' . filter_xss($old_node->log) . '
' : ''; @@ -248,7 +248,7 @@ function diff_diffs_show($node, $old_vid, $new_vid, $state = NULL) { ); } if (count($links) > 1) { - $state_links = theme('links', array( + $state_links = _theme('links', array( 'links' => $links, 'attributes' => array('class' => array('links', 'inline')), )); @@ -272,7 +272,7 @@ function diff_diffs_show($node, $old_vid, $new_vid, $state = NULL) { ); // Allow users to hide or set the display mode of the preview. - if (node_is_page($node) && $view_mode = variable_get('diff_view_mode_preview_node_' . $new_node->type, 'full')) { + if (node_is_page($node) && $view_mode = \Drupal::config('diff.settings')->get('diff_view_mode_preview_node_' . $new_node->type)) { $header = ''; if ($node->vid == $new_vid) { $header .= '' . filter_xss($old_node->log) . '
' : ''; + $new_log = $new_node->log != '' ? '' . filter_xss($new_node->log) . '
' : ''; + + // Generate previous diff/next diff links. + $nav_suffix = ($default_state != $state) ? '/' . str_replace('_', '-', $state) : ''; + $next_vid = _diff_get_next_vid($node_revisions, $new_vid); + if ($next_vid) { + $next_link = l(t('Next difference >'), 'node/' . $node->id() . '/revisions/view/' . $new_vid . '/' . $next_vid . $nav_suffix, array('absolute' => 1)); + } + else { + $next_link = ''; + } + $prev_vid = _diff_get_previous_vid($node_revisions, $old_vid); + if ($prev_vid) { + $prev_link = l(t('< Previous difference'), 'node/' . $node->id() . '/revisions/view/' . $prev_vid . '/' . $old_vid . $nav_suffix, array('absolute' => 1)); + } + else { + $prev_link = ''; + } + + $header = _diff_default_header($old_header, $new_header); + $rows = array(); + if ($old_log || $new_log) { + $rows['logs'] = array( + array( + 'data' => $old_log, + 'colspan' => 2, + ), + array( + 'data' => $new_log, + 'colspan' => 2, + ), + ); + } + $rows['navigation'] = array( + array( + 'data' => $prev_link, + 'class' => array('diff-prevlink'), + 'colspan' => 2, + ), + array( + 'data' => $next_link, + 'class' => array('diff-nextlink'), + 'colspan' => 2, + ), + ); + + $links = array(); + foreach (diff_available_states('node') as $alternative_state => $label) { + if ($alternative_state == $state) { + // @todo: Should we show both or just alternatives? + } + $links[$alternative_state] = array( + 'title' => $label, + 'href' => "node/{$node->id()}/revisions/view/{$old_vid}/{$new_vid}" . ($alternative_state == $default_state ? '' : '/' . str_replace('_', '-', $alternative_state)), + ); + } + if (count($links) > 1) { + $state_links = _theme('links', array( + 'links' => $links, + 'attributes' => array('class' => array('links', 'inline')), + )); + $rows['states'] = array( + array( + 'data' => $state_links, + 'class' => 'diff-links', + 'colspan' => 4, + ), + ); + } + $rows = array_merge($rows, _diff_body_rows($old_node, $new_node, $state)); + + $build['diff_table'] = array( + '#theme' => 'table__diff__standard', + '#header' => $header, + '#rows' => $rows, + '#attributes' => array('class' => array('diff')), + '#colgroups' => _diff_default_cols(), + '#sticky' => FALSE, + ); + + // Allow users to hide or set the display mode of the preview. + if (node_is_page($node) && $view_mode = \Drupal::config('diff.settings')->get('diff_view_mode_preview_node_' . $new_node->type)) { + $header = ''; + if ($node->vid == $new_vid) { + $header .= '' . t('This table provides a summary of the field type support found on the system. It is recommended that you use global settings whenever possible to configure field comparison settings.') . '
', + ); + + $header = array(t('Type'), t('Module'), t('Operations')); + $rows = array(); + + // Skip field types which have no widget types. + $field_types = \Drupal::service('plugin.manager.field.field_type')->getDefinitions(); + $widgets = array(); + foreach (field_info_widget_types() as $name => $widget_type) { + foreach ($widget_type['field types'] as $widget_field_type) { + if (isset($field_types[$widget_field_type])) { + $widgets[$widget_field_type][$name] = $widget_type['label']; + } + } + } + + foreach ($field_types as $field_name => $field_type) { + if (!empty($widgets[$field_name])) { + $row = array(); + $row[] = t('@field_label (%field_type)', array( + '@field_label' => $field_type['label'], + '%field_type' => $field_name, + )); + $row[] = $field_type['module']; + $row[] = l(t('Global settings'), 'admin/config/content/diff/fields/' . $field_name); + $rows[] = $row; + } + } + + $build['category_table'] = array( + '#theme' => 'table', + '#header' => $header, + '#rows' => $rows, + '#empty' => t('The system has no configurable fields.'), + ); + return $build; +} + +} diff --git a/src/Diff.php b/src/Diff.php new file mode 100644 index 0000000..f0c0d51 --- /dev/null +++ b/src/Diff.php @@ -0,0 +1,1355 @@ + + * You may copy this code freely under the conditions of the GPL. + */ + +define('USE_ASSERTS', FALSE); + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp { + var $type; + var $orig; + var $closing; + + function reverse() { + trigger_error('pure virtual', E_USER_ERROR); + } + + function norig() { + return $this->orig ? sizeof($this->orig) : 0; + } + + function nclosing() { + return $this->closing ? sizeof($this->closing) : 0; + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Copy extends _DiffOp { + var $type = 'copy'; + + function _DiffOp_Copy($orig, $closing = FALSE) { + if (!is_array($closing)) { + $closing = $orig; + } + $this->orig = $orig; + $this->closing = $closing; + } + + function reverse() { + return new _DiffOp_Copy($this->closing, $this->orig); + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Delete extends _DiffOp { + var $type = 'delete'; + + function _DiffOp_Delete($lines) { + $this->orig = $lines; + $this->closing = FALSE; + } + + function reverse() { + return new _DiffOp_Add($this->orig); + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Add extends _DiffOp { + var $type = 'add'; + + function _DiffOp_Add($lines) { + $this->closing = $lines; + $this->orig = FALSE; + } + + function reverse() { + return new _DiffOp_Delete($this->closing); + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Change extends _DiffOp { + var $type = 'change'; + + function _DiffOp_Change($orig, $closing) { + $this->orig = $orig; + $this->closing = $closing; + } + + function reverse() { + return new _DiffOp_Change($this->closing, $this->orig); + } +} + + +/** + * Class used internally by Diff to actually compute the diffs. + * + * The algorithm used here is mostly lifted from the perl module + * Algorithm::Diff (version 1.06) by Ned Konz, which is available at: + * http://www.perl.com/CPAN/authors/id/N/NE/NEDKONZ/Algorithm-Diff-1.06.zip + * + * More ideas are taken from: + * http://www.ics.uci.edu/~eppstein/161/960229.html + * + * Some ideas are (and a bit of code) are from from analyze.c, from GNU + * diffutils-2.7, which can be found at: + * ftp://gnudist.gnu.org/pub/gnu/diffutils/diffutils-2.7.tar.gz + * + * closingly, some ideas (subdivision by NCHUNKS > 2, and some optimizations) + * are my own. + * + * Line length limits for robustness added by Tim Starling, 2005-08-31 + * + * @author Geoffrey T. Dairiki, Tim Starling + * @private + * @subpackage DifferenceEngine + */ +class _DiffEngine { + function MAX_XREF_LENGTH() { + return 10000; + } + + function diff($from_lines, $to_lines) { + + $n_from = sizeof($from_lines); + $n_to = sizeof($to_lines); + + $this->xchanged = $this->ychanged = array(); + $this->xv = $this->yv = array(); + $this->xind = $this->yind = array(); + unset($this->seq); + unset($this->in_seq); + unset($this->lcs); + + // Skip leading common lines. + for ($skip = 0; $skip < $n_from && $skip < $n_to; $skip++) { + if ($from_lines[$skip] !== $to_lines[$skip]) { + break; + } + $this->xchanged[$skip] = $this->ychanged[$skip] = FALSE; + } + // Skip trailing common lines. + $xi = $n_from; + $yi = $n_to; + for ($endskip = 0; --$xi > $skip && --$yi > $skip; $endskip++) { + if ($from_lines[$xi] !== $to_lines[$yi]) { + break; + } + $this->xchanged[$xi] = $this->ychanged[$yi] = FALSE; + } + + // Ignore lines which do not exist in both files. + for ($xi = $skip; $xi < $n_from - $endskip; $xi++) { + $xhash[$this->_line_hash($from_lines[$xi])] = 1; + } + + for ($yi = $skip; $yi < $n_to - $endskip; $yi++) { + $line = $to_lines[$yi]; + if ($this->ychanged[$yi] = empty($xhash[$this->_line_hash($line)])) { + continue; + } + $yhash[$this->_line_hash($line)] = 1; + $this->yv[] = $line; + $this->yind[] = $yi; + } + for ($xi = $skip; $xi < $n_from - $endskip; $xi++) { + $line = $from_lines[$xi]; + if ($this->xchanged[$xi] = empty($yhash[$this->_line_hash($line)])) { + continue; + } + $this->xv[] = $line; + $this->xind[] = $xi; + } + + // Find the LCS. + $this->_compareseq(0, sizeof($this->xv), 0, sizeof($this->yv)); + + // Merge edits when possible + $this->_shift_boundaries($from_lines, $this->xchanged, $this->ychanged); + $this->_shift_boundaries($to_lines, $this->ychanged, $this->xchanged); + + // Compute the edit operations. + $edits = array(); + $xi = $yi = 0; + while ($xi < $n_from || $yi < $n_to) { + USE_ASSERTS && assert($yi < $n_to || $this->xchanged[$xi]); + USE_ASSERTS && assert($xi < $n_from || $this->ychanged[$yi]); + + // Skip matching "snake". + $copy = array(); + while ( $xi < $n_from && $yi < $n_to && !$this->xchanged[$xi] && !$this->ychanged[$yi]) { + $copy[] = $from_lines[$xi++]; + ++$yi; + } + if ($copy) { + $edits[] = new _DiffOp_Copy($copy); + } + // Find deletes & adds. + $delete = array(); + while ($xi < $n_from && $this->xchanged[$xi]) { + $_fl = $from_lines[$xi++]; + if (strlen($_fl)) { + $delete[] = $_fl; + } + } + $add = array(); + while ($yi < $n_to && $this->ychanged[$yi]) { + $_tl = $to_lines[$yi++]; + if (strlen($_tl)) { + $add[] = $_tl; + } + } + if ($delete && $add) { + $edits[] = new _DiffOp_Change($delete, $add); + } + elseif ($delete) { + $edits[] = new _DiffOp_Delete($delete); + } + elseif ($add) { + $edits[] = new _DiffOp_Add($add); + } + } + return $edits; + } + + /** + * Returns the whole line if it's small enough, or the MD5 hash otherwise. + */ + function _line_hash($line) { + if (drupal_strlen($line) > $this->MAX_XREF_LENGTH()) { + return md5($line); + } + else { + return $line; + } + } + + + /** + * Divide the Largest Common Subsequence (LCS) of the sequences + * [XOFF, XLIM) and [YOFF, YLIM) into NCHUNKS approximately equally + * sized segments. + * + * Returns (LCS, PTS). LCS is the length of the LCS. PTS is an + * array of NCHUNKS+1 (X, Y) indexes giving the diving points between + * sub sequences. The first sub-sequence is contained in [X0, X1), + * [Y0, Y1), the second in [X1, X2), [Y1, Y2) and so on. Note + * that (X0, Y0) == (XOFF, YOFF) and + * (X[NCHUNKS], Y[NCHUNKS]) == (XLIM, YLIM). + * + * This function assumes that the first lines of the specified portions + * of the two files do not match, and likewise that the last lines do not + * match. The caller must trim matching lines from the beginning and end + * of the portions it is going to specify. + */ + function _diag($xoff, $xlim, $yoff, $ylim, $nchunks) { + $flip = FALSE; + + if ($xlim - $xoff > $ylim - $yoff) { + // Things seems faster (I'm not sure I understand why) + // when the shortest sequence in X. + $flip = TRUE; + list($xoff, $xlim, $yoff, $ylim) = array($yoff, $ylim, $xoff, $xlim); + } + + if ($flip) { + for ($i = $ylim - 1; $i >= $yoff; $i--) { + $ymatches[$this->xv[$i]][] = $i; + } + } + else { + for ($i = $ylim - 1; $i >= $yoff; $i--) { + $ymatches[$this->yv[$i]][] = $i; + } + } + $this->lcs = 0; + $this->seq[0]= $yoff - 1; + $this->in_seq = array(); + $ymids[0] = array(); + + $numer = $xlim - $xoff + $nchunks - 1; + $x = $xoff; + for ($chunk = 0; $chunk < $nchunks; $chunk++) { + if ($chunk > 0) { + for ($i = 0; $i <= $this->lcs; $i++) { + $ymids[$i][$chunk-1] = $this->seq[$i]; + } + } + + $x1 = $xoff + (int)(($numer + ($xlim-$xoff)*$chunk) / $nchunks); + for ( ; $x < $x1; $x++) { + $line = $flip ? $this->yv[$x] : $this->xv[$x]; + if (empty($ymatches[$line])) { + continue; + } + $matches = $ymatches[$line]; + reset($matches); + while (list ($junk, $y) = each($matches)) { + if (empty($this->in_seq[$y])) { + $k = $this->_lcs_pos($y); + USE_ASSERTS && assert($k > 0); + $ymids[$k] = $ymids[$k-1]; + break; + } + } + while (list ($junk, $y) = each($matches)) { + if ($y > $this->seq[$k-1]) { + USE_ASSERTS && assert($y < $this->seq[$k]); + // Optimization: this is a common case: + // next match is just replacing previous match. + $this->in_seq[$this->seq[$k]] = FALSE; + $this->seq[$k] = $y; + $this->in_seq[$y] = 1; + } + elseif (empty($this->in_seq[$y])) { + $k = $this->_lcs_pos($y); + USE_ASSERTS && assert($k > 0); + $ymids[$k] = $ymids[$k-1]; + } + } + } + } + + $seps[] = $flip ? array($yoff, $xoff) : array($xoff, $yoff); + $ymid = $ymids[$this->lcs]; + for ($n = 0; $n < $nchunks - 1; $n++) { + $x1 = $xoff + (int)(($numer + ($xlim - $xoff) * $n) / $nchunks); + $y1 = $ymid[$n] + 1; + $seps[] = $flip ? array($y1, $x1) : array($x1, $y1); + } + $seps[] = $flip ? array($ylim, $xlim) : array($xlim, $ylim); + + return array($this->lcs, $seps); + } + + function _lcs_pos($ypos) { + + $end = $this->lcs; + if ($end == 0 || $ypos > $this->seq[$end]) { + $this->seq[++$this->lcs] = $ypos; + $this->in_seq[$ypos] = 1; + return $this->lcs; + } + + $beg = 1; + while ($beg < $end) { + $mid = (int)(($beg + $end) / 2); + if ($ypos > $this->seq[$mid]) { + $beg = $mid + 1; + } + else { + $end = $mid; + } + } + + USE_ASSERTS && assert($ypos != $this->seq[$end]); + + $this->in_seq[$this->seq[$end]] = FALSE; + $this->seq[$end] = $ypos; + $this->in_seq[$ypos] = 1; + return $end; + } + + /** + * Find LCS of two sequences. + * + * The results are recorded in the vectors $this->{x,y}changed[], by + * storing a 1 in the element for each line that is an insertion + * or deletion (ie. is not in the LCS). + * + * The subsequence of file 0 is [XOFF, XLIM) and likewise for file 1. + * + * Note that XLIM, YLIM are exclusive bounds. + * All line numbers are origin-0 and discarded lines are not counted. + */ + function _compareseq($xoff, $xlim, $yoff, $ylim) { + + // Slide down the bottom initial diagonal. + while ($xoff < $xlim && $yoff < $ylim && $this->xv[$xoff] == $this->yv[$yoff]) { + ++$xoff; + ++$yoff; + } + + // Slide up the top initial diagonal. + while ($xlim > $xoff && $ylim > $yoff && $this->xv[$xlim - 1] == $this->yv[$ylim - 1]) { + --$xlim; + --$ylim; + } + + if ($xoff == $xlim || $yoff == $ylim) { + $lcs = 0; + } + else { + // This is ad hoc but seems to work well. + //$nchunks = sqrt(min($xlim - $xoff, $ylim - $yoff) / 2.5); + //$nchunks = max(2, min(8, (int)$nchunks)); + $nchunks = min(7, $xlim - $xoff, $ylim - $yoff) + 1; + list($lcs, $seps) + = $this->_diag($xoff, $xlim, $yoff, $ylim, $nchunks); + } + + if ($lcs == 0) { + // X and Y sequences have no common subsequence: + // mark all changed. + while ($yoff < $ylim) { + $this->ychanged[$this->yind[$yoff++]] = 1; + } + while ($xoff < $xlim) { + $this->xchanged[$this->xind[$xoff++]] = 1; + } + } + else { + // Use the partitions to split this problem into subproblems. + reset($seps); + $pt1 = $seps[0]; + while ($pt2 = next($seps)) { + $this->_compareseq ($pt1[0], $pt2[0], $pt1[1], $pt2[1]); + $pt1 = $pt2; + } + } + } + + /** + * Adjust inserts/deletes of identical lines to join changes + * as much as possible. + * + * We do something when a run of changed lines include a + * line at one end and has an excluded, identical line at the other. + * We are free to choose which identical line is included. + * `compareseq' usually chooses the one at the beginning, + * but usually it is cleaner to consider the following identical line + * to be the "change". + * + * This is extracted verbatim from analyze.c (GNU diffutils-2.7). + */ + function _shift_boundaries($lines, &$changed, $other_changed) { + $i = 0; + $j = 0; + + USE_ASSERTS && assert('sizeof($lines) == sizeof($changed)'); + $len = sizeof($lines); + $other_len = sizeof($other_changed); + + while (1) { + /* + * Scan forwards to find beginning of another run of changes. + * Also keep track of the corresponding point in the other file. + * + * Throughout this code, $i and $j are adjusted together so that + * the first $i elements of $changed and the first $j elements + * of $other_changed both contain the same number of zeros + * (unchanged lines). + * Furthermore, $j is always kept so that $j == $other_len or + * $other_changed[$j] == FALSE. + */ + while ($j < $other_len && $other_changed[$j]) { + $j++; + } + while ($i < $len && ! $changed[$i]) { + USE_ASSERTS && assert('$j < $other_len && ! $other_changed[$j]'); + $i++; + $j++; + while ($j < $other_len && $other_changed[$j]) { + $j++; + } + } + + if ($i == $len) { + break; + } + $start = $i; + + // Find the end of this run of changes. + while (++$i < $len && $changed[$i]) { + continue; + } + + do { + /* + * Record the length of this run of changes, so that + * we can later determine whether the run has grown. + */ + $runlength = $i - $start; + + /* + * Move the changed region back, so long as the + * previous unchanged line matches the last changed one. + * This merges with previous changed regions. + */ + while ($start > 0 && $lines[$start - 1] == $lines[$i - 1]) { + $changed[--$start] = 1; + $changed[--$i] = FALSE; + while ($start > 0 && $changed[$start - 1]) { + $start--; + } + USE_ASSERTS && assert('$j > 0'); + while ($other_changed[--$j]) { + continue; + } + USE_ASSERTS && assert('$j >= 0 && !$other_changed[$j]'); + } + + /* + * Set CORRESPONDING to the end of the changed run, at the last + * point where it corresponds to a changed run in the other file. + * CORRESPONDING == LEN means no such point has been found. + */ + $corresponding = $j < $other_len ? $i : $len; + + /* + * Move the changed region forward, so long as the + * first changed line matches the following unchanged one. + * This merges with following changed regions. + * Do this second, so that if there are no merges, + * the changed region is moved forward as far as possible. + */ + while ($i < $len && $lines[$start] == $lines[$i]) { + $changed[$start++] = FALSE; + $changed[$i++] = 1; + while ($i < $len && $changed[$i]) { + $i++; + } + USE_ASSERTS && assert('$j < $other_len && ! $other_changed[$j]'); + $j++; + if ($j < $other_len && $other_changed[$j]) { + $corresponding = $i; + while ($j < $other_len && $other_changed[$j]) { + $j++; + } + } + } + } while ($runlength != $i - $start); + + /* + * If possible, move the fully-merged run of changes + * back to a corresponding run in the other file. + */ + while ($corresponding < $i) { + $changed[--$start] = 1; + $changed[--$i] = 0; + USE_ASSERTS && assert('$j > 0'); + while ($other_changed[--$j]) { + continue; + } + USE_ASSERTS && assert('$j >= 0 && !$other_changed[$j]'); + } + } + } +} + +/** + * Class representing a 'diff' between two sequences of strings. + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class Diff { + var $edits; + + /** + * Constructor. + * Computes diff between sequences of strings. + * + * @param $from_lines array An array of strings. + * (Typically these are lines from a file.) + * @param $to_lines array An array of strings. + */ + function Diff($from_lines, $to_lines) { + $eng = new _DiffEngine; + $this->edits = $eng->diff($from_lines, $to_lines); + //$this->_check($from_lines, $to_lines); + } + + /** + * Compute reversed Diff. + * + * SYNOPSIS: + * + * $diff = new Diff($lines1, $lines2); + * $rev = $diff->reverse(); + * @return object A Diff object representing the inverse of the + * original diff. + */ + function reverse() { + $rev = $this; + $rev->edits = array(); + foreach ($this->edits as $edit) { + $rev->edits[] = $edit->reverse(); + } + return $rev; + } + + /** + * Check for empty diff. + * + * @return bool True iff two sequences were identical. + */ + function isEmpty() { + foreach ($this->edits as $edit) { + if ($edit->type != 'copy') { + return FALSE; + } + } + return TRUE; + } + + /** + * Compute the length of the Longest Common Subsequence (LCS). + * + * This is mostly for diagnostic purposed. + * + * @return int The length of the LCS. + */ + function lcs() { + $lcs = 0; + foreach ($this->edits as $edit) { + if ($edit->type == 'copy') { + $lcs += sizeof($edit->orig); + } + } + return $lcs; + } + + /** + * Get the original set of lines. + * + * This reconstructs the $from_lines parameter passed to the + * constructor. + * + * @return array The original sequence of strings. + */ + function orig() { + $lines = array(); + + foreach ($this->edits as $edit) { + if ($edit->orig) { + array_splice($lines, sizeof($lines), 0, $edit->orig); + } + } + return $lines; + } + + /** + * Get the closing set of lines. + * + * This reconstructs the $to_lines parameter passed to the + * constructor. + * + * @return array The sequence of strings. + */ + function closing() { + $lines = array(); + + foreach ($this->edits as $edit) { + if ($edit->closing) { + array_splice($lines, sizeof($lines), 0, $edit->closing); + } + } + return $lines; + } + + /** + * Check a Diff for validity. + * + * This is here only for debugging purposes. + */ + function _check($from_lines, $to_lines) { + if (serialize($from_lines) != serialize($this->orig())) { + trigger_error("Reconstructed original doesn't match", E_USER_ERROR); + } + if (serialize($to_lines) != serialize($this->closing())) { + trigger_error("Reconstructed closing doesn't match", E_USER_ERROR); + } + + $rev = $this->reverse(); + if (serialize($to_lines) != serialize($rev->orig())) { + trigger_error("Reversed original doesn't match", E_USER_ERROR); + } + if (serialize($from_lines) != serialize($rev->closing())) { + trigger_error("Reversed closing doesn't match", E_USER_ERROR); + } + + + $prevtype = 'none'; + foreach ($this->edits as $edit) { + if ( $prevtype == $edit->type ) { + trigger_error("Edit sequence is non-optimal", E_USER_ERROR); + } + $prevtype = $edit->type; + } + + $lcs = $this->lcs(); + trigger_error('Diff okay: LCS = ' . $lcs, E_USER_NOTICE); + } +} + +/** + * FIXME: bad name. + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class MappedDiff extends Diff { + /** + * Constructor. + * + * Computes diff between sequences of strings. + * + * This can be used to compute things like + * case-insensitve diffs, or diffs which ignore + * changes in white-space. + * + * @param $from_lines array An array of strings. + * (Typically these are lines from a file.) + * + * @param $to_lines array An array of strings. + * + * @param $mapped_from_lines array This array should + * have the same size number of elements as $from_lines. + * The elements in $mapped_from_lines and + * $mapped_to_lines are what is actually compared + * when computing the diff. + * + * @param $mapped_to_lines array This array should + * have the same number of elements as $to_lines. + */ + function MappedDiff($from_lines, $to_lines, $mapped_from_lines, $mapped_to_lines) { + + assert(sizeof($from_lines) == sizeof($mapped_from_lines)); + assert(sizeof($to_lines) == sizeof($mapped_to_lines)); + + $this->Diff($mapped_from_lines, $mapped_to_lines); + + $xi = $yi = 0; + for ($i = 0; $i < sizeof($this->edits); $i++) { + $orig = &$this->edits[$i]->orig; + if (is_array($orig)) { + $orig = array_slice($from_lines, $xi, sizeof($orig)); + $xi += sizeof($orig); + } + + $closing = &$this->edits[$i]->closing; + if (is_array($closing)) { + $closing = array_slice($to_lines, $yi, sizeof($closing)); + $yi += sizeof($closing); + } + } + } +} + +/** + * A class to format Diffs + * + * This class formats the diff in classic diff format. + * It is intended that this class be customized via inheritance, + * to obtain fancier outputs. + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class DiffFormatter { + /** + * Should a block header be shown? + */ + var $show_header = TRUE; + + /** + * Number of leading context "lines" to preserve. + * + * This should be left at zero for this class, but subclasses + * may want to set this to other values. + */ + var $leading_context_lines = 0; + + /** + * Number of trailing context "lines" to preserve. + * + * This should be left at zero for this class, but subclasses + * may want to set this to other values. + */ + var $trailing_context_lines = 0; + + /** + * Format a diff. + * + * @param $diff object A Diff object. + * @return string The formatted output. + */ + function format($diff) { + $xi = $yi = 1; + $block = FALSE; + $context = array(); + + $nlead = $this->leading_context_lines; + $ntrail = $this->trailing_context_lines; + + $this->_start_diff(); + + foreach ($diff->edits as $edit) { + if ($edit->type == 'copy') { + if (is_array($block)) { + if (sizeof($edit->orig) <= $nlead + $ntrail) { + $block[] = $edit; + } + else { + if ($ntrail) { + $context = array_slice($edit->orig, 0, $ntrail); + $block[] = new _DiffOp_Copy($context); + } + $this->_block($x0, $ntrail + $xi - $x0, $y0, $ntrail + $yi - $y0, $block); + $block = FALSE; + } + } + $context = $edit->orig; + } + else { + if (! is_array($block)) { + $context = array_slice($context, sizeof($context) - $nlead); + $x0 = $xi - sizeof($context); + $y0 = $yi - sizeof($context); + $block = array(); + if ($context) { + $block[] = new _DiffOp_Copy($context); + } + } + $block[] = $edit; + } + + if ($edit->orig) { + $xi += sizeof($edit->orig); + } + if ($edit->closing) { + $yi += sizeof($edit->closing); + } + } + + if (is_array($block)) { + $this->_block($x0, $xi - $x0, $y0, $yi - $y0, $block); + } + $end = $this->_end_diff(); + + if (!empty($xi)) { + $this->line_stats['counter']['x'] += $xi; + } + if (!empty($yi)) { + $this->line_stats['counter']['y'] += $yi; + } + + return $end; + } + + function _block($xbeg, $xlen, $ybeg, $ylen, &$edits) { + $this->_start_block($this->_block_header($xbeg, $xlen, $ybeg, $ylen)); + foreach ($edits as $edit) { + if ($edit->type == 'copy') { + $this->_context($edit->orig); + } + elseif ($edit->type == 'add') { + $this->_added($edit->closing); + } + elseif ($edit->type == 'delete') { + $this->_deleted($edit->orig); + } + elseif ($edit->type == 'change') { + $this->_changed($edit->orig, $edit->closing); + } + else { + trigger_error('Unknown edit type', E_USER_ERROR); + } + } + $this->_end_block(); + } + + function _start_diff() { + ob_start(); + } + + function _end_diff() { + $val = ob_get_contents(); + ob_end_clean(); + return $val; + } + + function _block_header($xbeg, $xlen, $ybeg, $ylen) { + if ($xlen > 1) { + $xbeg .= "," . ($xbeg + $xlen - 1); + } + if ($ylen > 1) { + $ybeg .= "," . ($ybeg + $ylen - 1); + } + + return $xbeg . ($xlen ? ($ylen ? 'c' : 'd') : 'a') . $ybeg; + } + + function _start_block($header) { + if ($this->show_header) { + echo $header . "\n"; + } + } + + function _end_block() { + } + + function _lines($lines, $prefix = ' ') { + foreach ($lines as $line) { + echo "$prefix $line\n"; + } + } + + function _context($lines) { + $this->_lines($lines); + } + + function _added($lines) { + $this->_lines($lines, '>'); + } + function _deleted($lines) { + $this->_lines($lines, '<'); + } + + function _changed($orig, $closing) { + $this->_deleted($orig); + echo "---\n"; + $this->_added($closing); + } +} + + +/** + * Additions by Axel Boldt follow, partly taken from diff.php, phpwiki-1.3.3 + * + */ + +define('NBSP', ' '); // iso-8859-x non-breaking space. + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _HWLDF_WordAccumulator { + function _HWLDF_WordAccumulator() { + $this->_lines = array(); + $this->_line = ''; + $this->_group = ''; + $this->_tag = ''; + } + + function _flushGroup($new_tag) { + if ($this->_group !== '') { + if ($this->_tag == 'mark') { + $this->_line .= '' . check_plain($this->_group) . ''; + } + else { + $this->_line .= check_plain($this->_group); + } + } + $this->_group = ''; + $this->_tag = $new_tag; + } + + function _flushLine($new_tag) { + $this->_flushGroup($new_tag); + if ($this->_line != '') { + array_push($this->_lines, $this->_line); + } + else { + // make empty lines visible by inserting an NBSP + array_push($this->_lines, NBSP); + } + $this->_line = ''; + } + + function addWords($words, $tag = '') { + if ($tag != $this->_tag) { + $this->_flushGroup($tag); + } + foreach ($words as $word) { + // new-line should only come as first char of word. + if ($word == '') { + continue; + } + if ($word[0] == "\n") { + $this->_flushLine($tag); + $word = drupal_substr($word, 1); + } + assert(!strstr($word, "\n")); + $this->_group .= $word; + } + } + + function getLines() { + $this->_flushLine('~done'); + return $this->_lines; + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class WordLevelDiff extends MappedDiff { + function MAX_LINE_LENGTH() { + return 10000; + } + + function WordLevelDiff($orig_lines, $closing_lines) { + list($orig_words, $orig_stripped) = $this->_split($orig_lines); + list($closing_words, $closing_stripped) = $this->_split($closing_lines); + + $this->MappedDiff($orig_words, $closing_words, $orig_stripped, $closing_stripped); + } + + function _split($lines) { + $words = array(); + $stripped = array(); + $first = TRUE; + foreach ($lines as $line) { + // If the line is too long, just pretend the entire line is one big word + // This prevents resource exhaustion problems + if ( $first ) { + $first = FALSE; + } + else { + $words[] = "\n"; + $stripped[] = "\n"; + } + if ( drupal_strlen( $line ) > $this->MAX_LINE_LENGTH() ) { + $words[] = $line; + $stripped[] = $line; + } + else { + if (preg_match_all('/ ( [^\S\n]+ | [0-9_A-Za-z\x80-\xff]+ | . ) (?: (?!< \n) [^\S\n])? /xs', $line, $m)) { + $words = array_merge($words, $m[0]); + $stripped = array_merge($stripped, $m[1]); + } + } + } + return array($words, $stripped); + } + + function orig() { + $orig = new _HWLDF_WordAccumulator; + + foreach ($this->edits as $edit) { + if ($edit->type == 'copy') { + $orig->addWords($edit->orig); + } + elseif ($edit->orig) { + $orig->addWords($edit->orig, 'mark'); + } + } + $lines = $orig->getLines(); + return $lines; + } + + function closing() { + $closing = new _HWLDF_WordAccumulator; + + foreach ($this->edits as $edit) { + if ($edit->type == 'copy') { + $closing->addWords($edit->closing); + } + elseif ($edit->closing) { + $closing->addWords($edit->closing, 'mark'); + } + } + $lines = $closing->getLines(); + return $lines; + } +} + +/** + * Diff formatter which uses Drupal theme functions. + * @private + * @subpackage DifferenceEngine + */ +class DrupalDiffFormatter extends DiffFormatter { + + var $rows; + var $line_stats = array( + 'counter' => array('x' => 0, 'y' => 0), + 'offset' => array('x' => 0, 'y' => 0), + ); + + function DrupalDiffFormatter() { + $this->leading_context_lines = \Drupal::config('diff.settings')->get('diff_context_lines_leading'); + $this->trailing_context_lines = \Drupal::config('diff.settings')->get('diff_context_lines_trailing'); + } + + function _start_diff() { + $this->rows = array(); + } + + function _end_diff() { + return $this->rows; + } + + function _block_header($xbeg, $xlen, $ybeg, $ylen) { + return array( + array( + 'data' => _theme('diff_header_line', array('lineno' => $xbeg + $this->line_stats['offset']['x'])), + 'colspan' => 2, + ), + array( + 'data' => _theme('diff_header_line', array('lineno' => $ybeg + $this->line_stats['offset']['y'])), + 'colspan' => 2, + ) + ); + } + + function _start_block($header) { + if ($this->show_header) { + $this->rows[] = $header; + } + } + + function _end_block() { + } + + function _lines($lines, $prefix=' ', $color='white') { + } + + /** + * Note: you should HTML-escape parameter before calling this. + */ + function addedLine($line) { + return array( + array( + 'data' => '+', + 'class' => 'diff-marker', + ), + array( + 'data' => _theme('diff_content_line', array('line' => $line)), + 'class' => 'diff-context diff-addedline', + ) + ); + } + + /** + * Note: you should HTML-escape parameter before calling this. + */ + function deletedLine($line) { + return array( + array( + 'data' => '-', + 'class' => 'diff-marker', + ), + array( + 'data' => _theme('diff_content_line', array('line' => $line)), + 'class' => 'diff-context diff-deletedline', + ) + ); + } + + /** + * Note: you should HTML-escape parameter before calling this. + */ + function contextLine($line) { + return array( + ' ', + array( + 'data' => _theme('diff_content_line', array('line' => $line)), + 'class' => 'diff-context', + ) + ); + } + + function emptyLine() { + return array( + ' ', + _theme('diff_empty_line', array('line' => ' ')), + ); + } + + function _added($lines) { + foreach ($lines as $line) { + $this->rows[] = array_merge($this->emptyLine(), $this->addedLine(check_plain($line))); + } + } + + function _deleted($lines) { + foreach ($lines as $line) { + $this->rows[] = array_merge($this->deletedLine(check_plain($line)), $this->emptyLine()); + } + } + + function _context($lines) { + foreach ($lines as $line) { + $this->rows[] = array_merge($this->contextLine(check_plain($line)), $this->contextLine(check_plain($line))); + } + } + + function _changed($orig, $closing) { + $diff = new WordLevelDiff($orig, $closing); + $del = $diff->orig(); + $add = $diff->closing(); + + // Notice that WordLevelDiff returns HTML-escaped output. + // Hence, we will be calling addedLine/deletedLine without HTML-escaping. + + while ($line = array_shift($del)) { + $aline = array_shift( $add ); + $this->rows[] = array_merge($this->deletedLine($line), isset($aline) ? $this->addedLine($aline) : $this->emptyLine()); + } + foreach ($add as $line) { // If any leftovers + $this->rows[] = array_merge($this->emptyLine(), $this->addedLine($line)); + } + } +} + +/** + * Drupal inline Diff formatter. + * @private + * @subpackage DifferenceEngine + */ +class DrupalDiffInline { + var $a; + var $b; + + /** + * Constructor. + */ + function __construct($a, $b) { + $this->a = $a; + $this->b = $b; + } + + /** + * Render differences inline using HTML markup. + */ + function render() { + $a = preg_split('/(<[^>]+?>| )/', $this->a, -1, PREG_SPLIT_DELIM_CAPTURE); + $b = preg_split('/(<[^>]+?>| )/', $this->b, -1, PREG_SPLIT_DELIM_CAPTURE); + $diff = new Diff($a, $b); + $diff->edits = $this->process_edits($diff->edits); + + // Assemble highlighted output + $output = ''; + foreach ($diff->edits as $chunk) { + switch ($chunk->type) { + case 'copy': + $output .= implode('', $chunk->closing); + break; + case 'delete': + foreach ($chunk->orig as $i => $piece) { + if (strpos($piece, '<') === 0 && drupal_substr($piece, drupal_strlen($piece) - 1) === '>') { + $output .= $piece; + } + else { + $output .= _theme('diff_inline_chunk', array('text' => $piece, 'type' => $chunk->type)); + } + } + break; + default: + $chunk->closing = $this->process_chunk($chunk->closing); + foreach ($chunk->closing as $i => $piece) { + if ($piece === ' ' || (strpos($piece, '<') === 0 && drupal_substr($piece, drupal_strlen($piece) - 1) === '>' && drupal_strtolower(drupal_substr($piece, 1, 3)) != 'img')) { + $output .= $piece; + } + else { + $output .= _theme('diff_inline_chunk', array('text' => $piece, 'type' => $chunk->type)); + } + } + break; + } + } + return $output; + } + + /** + * Merge chunk segments between tag delimiters. + */ + function process_chunk($chunk) { + $processed = array(); + $j = 0; + foreach ($chunk as $i => $piece) { + $next = isset($chunk[$i+1]) ? $chunk[$i+1] : NULL; + if (!isset($processed[$j])) { + $processed[$j] = ''; + } + if (strpos($piece, '<') === 0 && drupal_substr($piece, drupal_strlen($piece) - 1) === '>') { + $processed[$j] = $piece; + $j++; + } + elseif (isset($next) && strpos($next, '<') === 0 && drupal_substr($next, drupal_strlen($next) - 1) === '>') { + $processed[$j] .= $piece; + $j++; + } + else { + $processed[$j] .= $piece; + } + } + return $processed; + } + + /** + * Merge copy and equivalent edits into intelligible chunks. + */ + function process_edits($edits) { + $processed = array(); + $current = array_shift($edits); + + // Make two passes -- first merge space delimiter copies back into their originals. + while ($chunk = array_shift($edits)) { + if ($chunk->type == 'copy' && $chunk->orig === array(' ')) { + $current->orig = array_merge((array) $current->orig, (array) $chunk->orig); + $current->closing = array_merge((array) $current->closing, (array) $chunk->closing); + } + else { + $processed[] = $current; + $current = $chunk; + } + } + $processed[] = $current; + + // Initial setup + $edits = $processed; + $processed = array(); + $current = array_shift($edits); + + // Second, merge equivalent chunks into each other. + while ($chunk = array_shift($edits)) { + if ($current->type == $chunk->type) { + $current->orig = array_merge((array) $current->orig, (array) $chunk->orig); + $current->closing = array_merge((array) $current->closing, (array) $chunk->closing); + } + else { + $processed[] = $current; + $current = $chunk; + } + } + $processed[] = $current; + + return $processed; + } +} diff --git a/src/DiffFormatter.php b/src/DiffFormatter.php new file mode 100644 index 0000000..f0c0d51 --- /dev/null +++ b/src/DiffFormatter.php @@ -0,0 +1,1355 @@ + + * You may copy this code freely under the conditions of the GPL. + */ + +define('USE_ASSERTS', FALSE); + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp { + var $type; + var $orig; + var $closing; + + function reverse() { + trigger_error('pure virtual', E_USER_ERROR); + } + + function norig() { + return $this->orig ? sizeof($this->orig) : 0; + } + + function nclosing() { + return $this->closing ? sizeof($this->closing) : 0; + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Copy extends _DiffOp { + var $type = 'copy'; + + function _DiffOp_Copy($orig, $closing = FALSE) { + if (!is_array($closing)) { + $closing = $orig; + } + $this->orig = $orig; + $this->closing = $closing; + } + + function reverse() { + return new _DiffOp_Copy($this->closing, $this->orig); + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Delete extends _DiffOp { + var $type = 'delete'; + + function _DiffOp_Delete($lines) { + $this->orig = $lines; + $this->closing = FALSE; + } + + function reverse() { + return new _DiffOp_Add($this->orig); + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Add extends _DiffOp { + var $type = 'add'; + + function _DiffOp_Add($lines) { + $this->closing = $lines; + $this->orig = FALSE; + } + + function reverse() { + return new _DiffOp_Delete($this->closing); + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Change extends _DiffOp { + var $type = 'change'; + + function _DiffOp_Change($orig, $closing) { + $this->orig = $orig; + $this->closing = $closing; + } + + function reverse() { + return new _DiffOp_Change($this->closing, $this->orig); + } +} + + +/** + * Class used internally by Diff to actually compute the diffs. + * + * The algorithm used here is mostly lifted from the perl module + * Algorithm::Diff (version 1.06) by Ned Konz, which is available at: + * http://www.perl.com/CPAN/authors/id/N/NE/NEDKONZ/Algorithm-Diff-1.06.zip + * + * More ideas are taken from: + * http://www.ics.uci.edu/~eppstein/161/960229.html + * + * Some ideas are (and a bit of code) are from from analyze.c, from GNU + * diffutils-2.7, which can be found at: + * ftp://gnudist.gnu.org/pub/gnu/diffutils/diffutils-2.7.tar.gz + * + * closingly, some ideas (subdivision by NCHUNKS > 2, and some optimizations) + * are my own. + * + * Line length limits for robustness added by Tim Starling, 2005-08-31 + * + * @author Geoffrey T. Dairiki, Tim Starling + * @private + * @subpackage DifferenceEngine + */ +class _DiffEngine { + function MAX_XREF_LENGTH() { + return 10000; + } + + function diff($from_lines, $to_lines) { + + $n_from = sizeof($from_lines); + $n_to = sizeof($to_lines); + + $this->xchanged = $this->ychanged = array(); + $this->xv = $this->yv = array(); + $this->xind = $this->yind = array(); + unset($this->seq); + unset($this->in_seq); + unset($this->lcs); + + // Skip leading common lines. + for ($skip = 0; $skip < $n_from && $skip < $n_to; $skip++) { + if ($from_lines[$skip] !== $to_lines[$skip]) { + break; + } + $this->xchanged[$skip] = $this->ychanged[$skip] = FALSE; + } + // Skip trailing common lines. + $xi = $n_from; + $yi = $n_to; + for ($endskip = 0; --$xi > $skip && --$yi > $skip; $endskip++) { + if ($from_lines[$xi] !== $to_lines[$yi]) { + break; + } + $this->xchanged[$xi] = $this->ychanged[$yi] = FALSE; + } + + // Ignore lines which do not exist in both files. + for ($xi = $skip; $xi < $n_from - $endskip; $xi++) { + $xhash[$this->_line_hash($from_lines[$xi])] = 1; + } + + for ($yi = $skip; $yi < $n_to - $endskip; $yi++) { + $line = $to_lines[$yi]; + if ($this->ychanged[$yi] = empty($xhash[$this->_line_hash($line)])) { + continue; + } + $yhash[$this->_line_hash($line)] = 1; + $this->yv[] = $line; + $this->yind[] = $yi; + } + for ($xi = $skip; $xi < $n_from - $endskip; $xi++) { + $line = $from_lines[$xi]; + if ($this->xchanged[$xi] = empty($yhash[$this->_line_hash($line)])) { + continue; + } + $this->xv[] = $line; + $this->xind[] = $xi; + } + + // Find the LCS. + $this->_compareseq(0, sizeof($this->xv), 0, sizeof($this->yv)); + + // Merge edits when possible + $this->_shift_boundaries($from_lines, $this->xchanged, $this->ychanged); + $this->_shift_boundaries($to_lines, $this->ychanged, $this->xchanged); + + // Compute the edit operations. + $edits = array(); + $xi = $yi = 0; + while ($xi < $n_from || $yi < $n_to) { + USE_ASSERTS && assert($yi < $n_to || $this->xchanged[$xi]); + USE_ASSERTS && assert($xi < $n_from || $this->ychanged[$yi]); + + // Skip matching "snake". + $copy = array(); + while ( $xi < $n_from && $yi < $n_to && !$this->xchanged[$xi] && !$this->ychanged[$yi]) { + $copy[] = $from_lines[$xi++]; + ++$yi; + } + if ($copy) { + $edits[] = new _DiffOp_Copy($copy); + } + // Find deletes & adds. + $delete = array(); + while ($xi < $n_from && $this->xchanged[$xi]) { + $_fl = $from_lines[$xi++]; + if (strlen($_fl)) { + $delete[] = $_fl; + } + } + $add = array(); + while ($yi < $n_to && $this->ychanged[$yi]) { + $_tl = $to_lines[$yi++]; + if (strlen($_tl)) { + $add[] = $_tl; + } + } + if ($delete && $add) { + $edits[] = new _DiffOp_Change($delete, $add); + } + elseif ($delete) { + $edits[] = new _DiffOp_Delete($delete); + } + elseif ($add) { + $edits[] = new _DiffOp_Add($add); + } + } + return $edits; + } + + /** + * Returns the whole line if it's small enough, or the MD5 hash otherwise. + */ + function _line_hash($line) { + if (drupal_strlen($line) > $this->MAX_XREF_LENGTH()) { + return md5($line); + } + else { + return $line; + } + } + + + /** + * Divide the Largest Common Subsequence (LCS) of the sequences + * [XOFF, XLIM) and [YOFF, YLIM) into NCHUNKS approximately equally + * sized segments. + * + * Returns (LCS, PTS). LCS is the length of the LCS. PTS is an + * array of NCHUNKS+1 (X, Y) indexes giving the diving points between + * sub sequences. The first sub-sequence is contained in [X0, X1), + * [Y0, Y1), the second in [X1, X2), [Y1, Y2) and so on. Note + * that (X0, Y0) == (XOFF, YOFF) and + * (X[NCHUNKS], Y[NCHUNKS]) == (XLIM, YLIM). + * + * This function assumes that the first lines of the specified portions + * of the two files do not match, and likewise that the last lines do not + * match. The caller must trim matching lines from the beginning and end + * of the portions it is going to specify. + */ + function _diag($xoff, $xlim, $yoff, $ylim, $nchunks) { + $flip = FALSE; + + if ($xlim - $xoff > $ylim - $yoff) { + // Things seems faster (I'm not sure I understand why) + // when the shortest sequence in X. + $flip = TRUE; + list($xoff, $xlim, $yoff, $ylim) = array($yoff, $ylim, $xoff, $xlim); + } + + if ($flip) { + for ($i = $ylim - 1; $i >= $yoff; $i--) { + $ymatches[$this->xv[$i]][] = $i; + } + } + else { + for ($i = $ylim - 1; $i >= $yoff; $i--) { + $ymatches[$this->yv[$i]][] = $i; + } + } + $this->lcs = 0; + $this->seq[0]= $yoff - 1; + $this->in_seq = array(); + $ymids[0] = array(); + + $numer = $xlim - $xoff + $nchunks - 1; + $x = $xoff; + for ($chunk = 0; $chunk < $nchunks; $chunk++) { + if ($chunk > 0) { + for ($i = 0; $i <= $this->lcs; $i++) { + $ymids[$i][$chunk-1] = $this->seq[$i]; + } + } + + $x1 = $xoff + (int)(($numer + ($xlim-$xoff)*$chunk) / $nchunks); + for ( ; $x < $x1; $x++) { + $line = $flip ? $this->yv[$x] : $this->xv[$x]; + if (empty($ymatches[$line])) { + continue; + } + $matches = $ymatches[$line]; + reset($matches); + while (list ($junk, $y) = each($matches)) { + if (empty($this->in_seq[$y])) { + $k = $this->_lcs_pos($y); + USE_ASSERTS && assert($k > 0); + $ymids[$k] = $ymids[$k-1]; + break; + } + } + while (list ($junk, $y) = each($matches)) { + if ($y > $this->seq[$k-1]) { + USE_ASSERTS && assert($y < $this->seq[$k]); + // Optimization: this is a common case: + // next match is just replacing previous match. + $this->in_seq[$this->seq[$k]] = FALSE; + $this->seq[$k] = $y; + $this->in_seq[$y] = 1; + } + elseif (empty($this->in_seq[$y])) { + $k = $this->_lcs_pos($y); + USE_ASSERTS && assert($k > 0); + $ymids[$k] = $ymids[$k-1]; + } + } + } + } + + $seps[] = $flip ? array($yoff, $xoff) : array($xoff, $yoff); + $ymid = $ymids[$this->lcs]; + for ($n = 0; $n < $nchunks - 1; $n++) { + $x1 = $xoff + (int)(($numer + ($xlim - $xoff) * $n) / $nchunks); + $y1 = $ymid[$n] + 1; + $seps[] = $flip ? array($y1, $x1) : array($x1, $y1); + } + $seps[] = $flip ? array($ylim, $xlim) : array($xlim, $ylim); + + return array($this->lcs, $seps); + } + + function _lcs_pos($ypos) { + + $end = $this->lcs; + if ($end == 0 || $ypos > $this->seq[$end]) { + $this->seq[++$this->lcs] = $ypos; + $this->in_seq[$ypos] = 1; + return $this->lcs; + } + + $beg = 1; + while ($beg < $end) { + $mid = (int)(($beg + $end) / 2); + if ($ypos > $this->seq[$mid]) { + $beg = $mid + 1; + } + else { + $end = $mid; + } + } + + USE_ASSERTS && assert($ypos != $this->seq[$end]); + + $this->in_seq[$this->seq[$end]] = FALSE; + $this->seq[$end] = $ypos; + $this->in_seq[$ypos] = 1; + return $end; + } + + /** + * Find LCS of two sequences. + * + * The results are recorded in the vectors $this->{x,y}changed[], by + * storing a 1 in the element for each line that is an insertion + * or deletion (ie. is not in the LCS). + * + * The subsequence of file 0 is [XOFF, XLIM) and likewise for file 1. + * + * Note that XLIM, YLIM are exclusive bounds. + * All line numbers are origin-0 and discarded lines are not counted. + */ + function _compareseq($xoff, $xlim, $yoff, $ylim) { + + // Slide down the bottom initial diagonal. + while ($xoff < $xlim && $yoff < $ylim && $this->xv[$xoff] == $this->yv[$yoff]) { + ++$xoff; + ++$yoff; + } + + // Slide up the top initial diagonal. + while ($xlim > $xoff && $ylim > $yoff && $this->xv[$xlim - 1] == $this->yv[$ylim - 1]) { + --$xlim; + --$ylim; + } + + if ($xoff == $xlim || $yoff == $ylim) { + $lcs = 0; + } + else { + // This is ad hoc but seems to work well. + //$nchunks = sqrt(min($xlim - $xoff, $ylim - $yoff) / 2.5); + //$nchunks = max(2, min(8, (int)$nchunks)); + $nchunks = min(7, $xlim - $xoff, $ylim - $yoff) + 1; + list($lcs, $seps) + = $this->_diag($xoff, $xlim, $yoff, $ylim, $nchunks); + } + + if ($lcs == 0) { + // X and Y sequences have no common subsequence: + // mark all changed. + while ($yoff < $ylim) { + $this->ychanged[$this->yind[$yoff++]] = 1; + } + while ($xoff < $xlim) { + $this->xchanged[$this->xind[$xoff++]] = 1; + } + } + else { + // Use the partitions to split this problem into subproblems. + reset($seps); + $pt1 = $seps[0]; + while ($pt2 = next($seps)) { + $this->_compareseq ($pt1[0], $pt2[0], $pt1[1], $pt2[1]); + $pt1 = $pt2; + } + } + } + + /** + * Adjust inserts/deletes of identical lines to join changes + * as much as possible. + * + * We do something when a run of changed lines include a + * line at one end and has an excluded, identical line at the other. + * We are free to choose which identical line is included. + * `compareseq' usually chooses the one at the beginning, + * but usually it is cleaner to consider the following identical line + * to be the "change". + * + * This is extracted verbatim from analyze.c (GNU diffutils-2.7). + */ + function _shift_boundaries($lines, &$changed, $other_changed) { + $i = 0; + $j = 0; + + USE_ASSERTS && assert('sizeof($lines) == sizeof($changed)'); + $len = sizeof($lines); + $other_len = sizeof($other_changed); + + while (1) { + /* + * Scan forwards to find beginning of another run of changes. + * Also keep track of the corresponding point in the other file. + * + * Throughout this code, $i and $j are adjusted together so that + * the first $i elements of $changed and the first $j elements + * of $other_changed both contain the same number of zeros + * (unchanged lines). + * Furthermore, $j is always kept so that $j == $other_len or + * $other_changed[$j] == FALSE. + */ + while ($j < $other_len && $other_changed[$j]) { + $j++; + } + while ($i < $len && ! $changed[$i]) { + USE_ASSERTS && assert('$j < $other_len && ! $other_changed[$j]'); + $i++; + $j++; + while ($j < $other_len && $other_changed[$j]) { + $j++; + } + } + + if ($i == $len) { + break; + } + $start = $i; + + // Find the end of this run of changes. + while (++$i < $len && $changed[$i]) { + continue; + } + + do { + /* + * Record the length of this run of changes, so that + * we can later determine whether the run has grown. + */ + $runlength = $i - $start; + + /* + * Move the changed region back, so long as the + * previous unchanged line matches the last changed one. + * This merges with previous changed regions. + */ + while ($start > 0 && $lines[$start - 1] == $lines[$i - 1]) { + $changed[--$start] = 1; + $changed[--$i] = FALSE; + while ($start > 0 && $changed[$start - 1]) { + $start--; + } + USE_ASSERTS && assert('$j > 0'); + while ($other_changed[--$j]) { + continue; + } + USE_ASSERTS && assert('$j >= 0 && !$other_changed[$j]'); + } + + /* + * Set CORRESPONDING to the end of the changed run, at the last + * point where it corresponds to a changed run in the other file. + * CORRESPONDING == LEN means no such point has been found. + */ + $corresponding = $j < $other_len ? $i : $len; + + /* + * Move the changed region forward, so long as the + * first changed line matches the following unchanged one. + * This merges with following changed regions. + * Do this second, so that if there are no merges, + * the changed region is moved forward as far as possible. + */ + while ($i < $len && $lines[$start] == $lines[$i]) { + $changed[$start++] = FALSE; + $changed[$i++] = 1; + while ($i < $len && $changed[$i]) { + $i++; + } + USE_ASSERTS && assert('$j < $other_len && ! $other_changed[$j]'); + $j++; + if ($j < $other_len && $other_changed[$j]) { + $corresponding = $i; + while ($j < $other_len && $other_changed[$j]) { + $j++; + } + } + } + } while ($runlength != $i - $start); + + /* + * If possible, move the fully-merged run of changes + * back to a corresponding run in the other file. + */ + while ($corresponding < $i) { + $changed[--$start] = 1; + $changed[--$i] = 0; + USE_ASSERTS && assert('$j > 0'); + while ($other_changed[--$j]) { + continue; + } + USE_ASSERTS && assert('$j >= 0 && !$other_changed[$j]'); + } + } + } +} + +/** + * Class representing a 'diff' between two sequences of strings. + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class Diff { + var $edits; + + /** + * Constructor. + * Computes diff between sequences of strings. + * + * @param $from_lines array An array of strings. + * (Typically these are lines from a file.) + * @param $to_lines array An array of strings. + */ + function Diff($from_lines, $to_lines) { + $eng = new _DiffEngine; + $this->edits = $eng->diff($from_lines, $to_lines); + //$this->_check($from_lines, $to_lines); + } + + /** + * Compute reversed Diff. + * + * SYNOPSIS: + * + * $diff = new Diff($lines1, $lines2); + * $rev = $diff->reverse(); + * @return object A Diff object representing the inverse of the + * original diff. + */ + function reverse() { + $rev = $this; + $rev->edits = array(); + foreach ($this->edits as $edit) { + $rev->edits[] = $edit->reverse(); + } + return $rev; + } + + /** + * Check for empty diff. + * + * @return bool True iff two sequences were identical. + */ + function isEmpty() { + foreach ($this->edits as $edit) { + if ($edit->type != 'copy') { + return FALSE; + } + } + return TRUE; + } + + /** + * Compute the length of the Longest Common Subsequence (LCS). + * + * This is mostly for diagnostic purposed. + * + * @return int The length of the LCS. + */ + function lcs() { + $lcs = 0; + foreach ($this->edits as $edit) { + if ($edit->type == 'copy') { + $lcs += sizeof($edit->orig); + } + } + return $lcs; + } + + /** + * Get the original set of lines. + * + * This reconstructs the $from_lines parameter passed to the + * constructor. + * + * @return array The original sequence of strings. + */ + function orig() { + $lines = array(); + + foreach ($this->edits as $edit) { + if ($edit->orig) { + array_splice($lines, sizeof($lines), 0, $edit->orig); + } + } + return $lines; + } + + /** + * Get the closing set of lines. + * + * This reconstructs the $to_lines parameter passed to the + * constructor. + * + * @return array The sequence of strings. + */ + function closing() { + $lines = array(); + + foreach ($this->edits as $edit) { + if ($edit->closing) { + array_splice($lines, sizeof($lines), 0, $edit->closing); + } + } + return $lines; + } + + /** + * Check a Diff for validity. + * + * This is here only for debugging purposes. + */ + function _check($from_lines, $to_lines) { + if (serialize($from_lines) != serialize($this->orig())) { + trigger_error("Reconstructed original doesn't match", E_USER_ERROR); + } + if (serialize($to_lines) != serialize($this->closing())) { + trigger_error("Reconstructed closing doesn't match", E_USER_ERROR); + } + + $rev = $this->reverse(); + if (serialize($to_lines) != serialize($rev->orig())) { + trigger_error("Reversed original doesn't match", E_USER_ERROR); + } + if (serialize($from_lines) != serialize($rev->closing())) { + trigger_error("Reversed closing doesn't match", E_USER_ERROR); + } + + + $prevtype = 'none'; + foreach ($this->edits as $edit) { + if ( $prevtype == $edit->type ) { + trigger_error("Edit sequence is non-optimal", E_USER_ERROR); + } + $prevtype = $edit->type; + } + + $lcs = $this->lcs(); + trigger_error('Diff okay: LCS = ' . $lcs, E_USER_NOTICE); + } +} + +/** + * FIXME: bad name. + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class MappedDiff extends Diff { + /** + * Constructor. + * + * Computes diff between sequences of strings. + * + * This can be used to compute things like + * case-insensitve diffs, or diffs which ignore + * changes in white-space. + * + * @param $from_lines array An array of strings. + * (Typically these are lines from a file.) + * + * @param $to_lines array An array of strings. + * + * @param $mapped_from_lines array This array should + * have the same size number of elements as $from_lines. + * The elements in $mapped_from_lines and + * $mapped_to_lines are what is actually compared + * when computing the diff. + * + * @param $mapped_to_lines array This array should + * have the same number of elements as $to_lines. + */ + function MappedDiff($from_lines, $to_lines, $mapped_from_lines, $mapped_to_lines) { + + assert(sizeof($from_lines) == sizeof($mapped_from_lines)); + assert(sizeof($to_lines) == sizeof($mapped_to_lines)); + + $this->Diff($mapped_from_lines, $mapped_to_lines); + + $xi = $yi = 0; + for ($i = 0; $i < sizeof($this->edits); $i++) { + $orig = &$this->edits[$i]->orig; + if (is_array($orig)) { + $orig = array_slice($from_lines, $xi, sizeof($orig)); + $xi += sizeof($orig); + } + + $closing = &$this->edits[$i]->closing; + if (is_array($closing)) { + $closing = array_slice($to_lines, $yi, sizeof($closing)); + $yi += sizeof($closing); + } + } + } +} + +/** + * A class to format Diffs + * + * This class formats the diff in classic diff format. + * It is intended that this class be customized via inheritance, + * to obtain fancier outputs. + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class DiffFormatter { + /** + * Should a block header be shown? + */ + var $show_header = TRUE; + + /** + * Number of leading context "lines" to preserve. + * + * This should be left at zero for this class, but subclasses + * may want to set this to other values. + */ + var $leading_context_lines = 0; + + /** + * Number of trailing context "lines" to preserve. + * + * This should be left at zero for this class, but subclasses + * may want to set this to other values. + */ + var $trailing_context_lines = 0; + + /** + * Format a diff. + * + * @param $diff object A Diff object. + * @return string The formatted output. + */ + function format($diff) { + $xi = $yi = 1; + $block = FALSE; + $context = array(); + + $nlead = $this->leading_context_lines; + $ntrail = $this->trailing_context_lines; + + $this->_start_diff(); + + foreach ($diff->edits as $edit) { + if ($edit->type == 'copy') { + if (is_array($block)) { + if (sizeof($edit->orig) <= $nlead + $ntrail) { + $block[] = $edit; + } + else { + if ($ntrail) { + $context = array_slice($edit->orig, 0, $ntrail); + $block[] = new _DiffOp_Copy($context); + } + $this->_block($x0, $ntrail + $xi - $x0, $y0, $ntrail + $yi - $y0, $block); + $block = FALSE; + } + } + $context = $edit->orig; + } + else { + if (! is_array($block)) { + $context = array_slice($context, sizeof($context) - $nlead); + $x0 = $xi - sizeof($context); + $y0 = $yi - sizeof($context); + $block = array(); + if ($context) { + $block[] = new _DiffOp_Copy($context); + } + } + $block[] = $edit; + } + + if ($edit->orig) { + $xi += sizeof($edit->orig); + } + if ($edit->closing) { + $yi += sizeof($edit->closing); + } + } + + if (is_array($block)) { + $this->_block($x0, $xi - $x0, $y0, $yi - $y0, $block); + } + $end = $this->_end_diff(); + + if (!empty($xi)) { + $this->line_stats['counter']['x'] += $xi; + } + if (!empty($yi)) { + $this->line_stats['counter']['y'] += $yi; + } + + return $end; + } + + function _block($xbeg, $xlen, $ybeg, $ylen, &$edits) { + $this->_start_block($this->_block_header($xbeg, $xlen, $ybeg, $ylen)); + foreach ($edits as $edit) { + if ($edit->type == 'copy') { + $this->_context($edit->orig); + } + elseif ($edit->type == 'add') { + $this->_added($edit->closing); + } + elseif ($edit->type == 'delete') { + $this->_deleted($edit->orig); + } + elseif ($edit->type == 'change') { + $this->_changed($edit->orig, $edit->closing); + } + else { + trigger_error('Unknown edit type', E_USER_ERROR); + } + } + $this->_end_block(); + } + + function _start_diff() { + ob_start(); + } + + function _end_diff() { + $val = ob_get_contents(); + ob_end_clean(); + return $val; + } + + function _block_header($xbeg, $xlen, $ybeg, $ylen) { + if ($xlen > 1) { + $xbeg .= "," . ($xbeg + $xlen - 1); + } + if ($ylen > 1) { + $ybeg .= "," . ($ybeg + $ylen - 1); + } + + return $xbeg . ($xlen ? ($ylen ? 'c' : 'd') : 'a') . $ybeg; + } + + function _start_block($header) { + if ($this->show_header) { + echo $header . "\n"; + } + } + + function _end_block() { + } + + function _lines($lines, $prefix = ' ') { + foreach ($lines as $line) { + echo "$prefix $line\n"; + } + } + + function _context($lines) { + $this->_lines($lines); + } + + function _added($lines) { + $this->_lines($lines, '>'); + } + function _deleted($lines) { + $this->_lines($lines, '<'); + } + + function _changed($orig, $closing) { + $this->_deleted($orig); + echo "---\n"; + $this->_added($closing); + } +} + + +/** + * Additions by Axel Boldt follow, partly taken from diff.php, phpwiki-1.3.3 + * + */ + +define('NBSP', ' '); // iso-8859-x non-breaking space. + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _HWLDF_WordAccumulator { + function _HWLDF_WordAccumulator() { + $this->_lines = array(); + $this->_line = ''; + $this->_group = ''; + $this->_tag = ''; + } + + function _flushGroup($new_tag) { + if ($this->_group !== '') { + if ($this->_tag == 'mark') { + $this->_line .= '' . check_plain($this->_group) . ''; + } + else { + $this->_line .= check_plain($this->_group); + } + } + $this->_group = ''; + $this->_tag = $new_tag; + } + + function _flushLine($new_tag) { + $this->_flushGroup($new_tag); + if ($this->_line != '') { + array_push($this->_lines, $this->_line); + } + else { + // make empty lines visible by inserting an NBSP + array_push($this->_lines, NBSP); + } + $this->_line = ''; + } + + function addWords($words, $tag = '') { + if ($tag != $this->_tag) { + $this->_flushGroup($tag); + } + foreach ($words as $word) { + // new-line should only come as first char of word. + if ($word == '') { + continue; + } + if ($word[0] == "\n") { + $this->_flushLine($tag); + $word = drupal_substr($word, 1); + } + assert(!strstr($word, "\n")); + $this->_group .= $word; + } + } + + function getLines() { + $this->_flushLine('~done'); + return $this->_lines; + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class WordLevelDiff extends MappedDiff { + function MAX_LINE_LENGTH() { + return 10000; + } + + function WordLevelDiff($orig_lines, $closing_lines) { + list($orig_words, $orig_stripped) = $this->_split($orig_lines); + list($closing_words, $closing_stripped) = $this->_split($closing_lines); + + $this->MappedDiff($orig_words, $closing_words, $orig_stripped, $closing_stripped); + } + + function _split($lines) { + $words = array(); + $stripped = array(); + $first = TRUE; + foreach ($lines as $line) { + // If the line is too long, just pretend the entire line is one big word + // This prevents resource exhaustion problems + if ( $first ) { + $first = FALSE; + } + else { + $words[] = "\n"; + $stripped[] = "\n"; + } + if ( drupal_strlen( $line ) > $this->MAX_LINE_LENGTH() ) { + $words[] = $line; + $stripped[] = $line; + } + else { + if (preg_match_all('/ ( [^\S\n]+ | [0-9_A-Za-z\x80-\xff]+ | . ) (?: (?!< \n) [^\S\n])? /xs', $line, $m)) { + $words = array_merge($words, $m[0]); + $stripped = array_merge($stripped, $m[1]); + } + } + } + return array($words, $stripped); + } + + function orig() { + $orig = new _HWLDF_WordAccumulator; + + foreach ($this->edits as $edit) { + if ($edit->type == 'copy') { + $orig->addWords($edit->orig); + } + elseif ($edit->orig) { + $orig->addWords($edit->orig, 'mark'); + } + } + $lines = $orig->getLines(); + return $lines; + } + + function closing() { + $closing = new _HWLDF_WordAccumulator; + + foreach ($this->edits as $edit) { + if ($edit->type == 'copy') { + $closing->addWords($edit->closing); + } + elseif ($edit->closing) { + $closing->addWords($edit->closing, 'mark'); + } + } + $lines = $closing->getLines(); + return $lines; + } +} + +/** + * Diff formatter which uses Drupal theme functions. + * @private + * @subpackage DifferenceEngine + */ +class DrupalDiffFormatter extends DiffFormatter { + + var $rows; + var $line_stats = array( + 'counter' => array('x' => 0, 'y' => 0), + 'offset' => array('x' => 0, 'y' => 0), + ); + + function DrupalDiffFormatter() { + $this->leading_context_lines = \Drupal::config('diff.settings')->get('diff_context_lines_leading'); + $this->trailing_context_lines = \Drupal::config('diff.settings')->get('diff_context_lines_trailing'); + } + + function _start_diff() { + $this->rows = array(); + } + + function _end_diff() { + return $this->rows; + } + + function _block_header($xbeg, $xlen, $ybeg, $ylen) { + return array( + array( + 'data' => _theme('diff_header_line', array('lineno' => $xbeg + $this->line_stats['offset']['x'])), + 'colspan' => 2, + ), + array( + 'data' => _theme('diff_header_line', array('lineno' => $ybeg + $this->line_stats['offset']['y'])), + 'colspan' => 2, + ) + ); + } + + function _start_block($header) { + if ($this->show_header) { + $this->rows[] = $header; + } + } + + function _end_block() { + } + + function _lines($lines, $prefix=' ', $color='white') { + } + + /** + * Note: you should HTML-escape parameter before calling this. + */ + function addedLine($line) { + return array( + array( + 'data' => '+', + 'class' => 'diff-marker', + ), + array( + 'data' => _theme('diff_content_line', array('line' => $line)), + 'class' => 'diff-context diff-addedline', + ) + ); + } + + /** + * Note: you should HTML-escape parameter before calling this. + */ + function deletedLine($line) { + return array( + array( + 'data' => '-', + 'class' => 'diff-marker', + ), + array( + 'data' => _theme('diff_content_line', array('line' => $line)), + 'class' => 'diff-context diff-deletedline', + ) + ); + } + + /** + * Note: you should HTML-escape parameter before calling this. + */ + function contextLine($line) { + return array( + ' ', + array( + 'data' => _theme('diff_content_line', array('line' => $line)), + 'class' => 'diff-context', + ) + ); + } + + function emptyLine() { + return array( + ' ', + _theme('diff_empty_line', array('line' => ' ')), + ); + } + + function _added($lines) { + foreach ($lines as $line) { + $this->rows[] = array_merge($this->emptyLine(), $this->addedLine(check_plain($line))); + } + } + + function _deleted($lines) { + foreach ($lines as $line) { + $this->rows[] = array_merge($this->deletedLine(check_plain($line)), $this->emptyLine()); + } + } + + function _context($lines) { + foreach ($lines as $line) { + $this->rows[] = array_merge($this->contextLine(check_plain($line)), $this->contextLine(check_plain($line))); + } + } + + function _changed($orig, $closing) { + $diff = new WordLevelDiff($orig, $closing); + $del = $diff->orig(); + $add = $diff->closing(); + + // Notice that WordLevelDiff returns HTML-escaped output. + // Hence, we will be calling addedLine/deletedLine without HTML-escaping. + + while ($line = array_shift($del)) { + $aline = array_shift( $add ); + $this->rows[] = array_merge($this->deletedLine($line), isset($aline) ? $this->addedLine($aline) : $this->emptyLine()); + } + foreach ($add as $line) { // If any leftovers + $this->rows[] = array_merge($this->emptyLine(), $this->addedLine($line)); + } + } +} + +/** + * Drupal inline Diff formatter. + * @private + * @subpackage DifferenceEngine + */ +class DrupalDiffInline { + var $a; + var $b; + + /** + * Constructor. + */ + function __construct($a, $b) { + $this->a = $a; + $this->b = $b; + } + + /** + * Render differences inline using HTML markup. + */ + function render() { + $a = preg_split('/(<[^>]+?>| )/', $this->a, -1, PREG_SPLIT_DELIM_CAPTURE); + $b = preg_split('/(<[^>]+?>| )/', $this->b, -1, PREG_SPLIT_DELIM_CAPTURE); + $diff = new Diff($a, $b); + $diff->edits = $this->process_edits($diff->edits); + + // Assemble highlighted output + $output = ''; + foreach ($diff->edits as $chunk) { + switch ($chunk->type) { + case 'copy': + $output .= implode('', $chunk->closing); + break; + case 'delete': + foreach ($chunk->orig as $i => $piece) { + if (strpos($piece, '<') === 0 && drupal_substr($piece, drupal_strlen($piece) - 1) === '>') { + $output .= $piece; + } + else { + $output .= _theme('diff_inline_chunk', array('text' => $piece, 'type' => $chunk->type)); + } + } + break; + default: + $chunk->closing = $this->process_chunk($chunk->closing); + foreach ($chunk->closing as $i => $piece) { + if ($piece === ' ' || (strpos($piece, '<') === 0 && drupal_substr($piece, drupal_strlen($piece) - 1) === '>' && drupal_strtolower(drupal_substr($piece, 1, 3)) != 'img')) { + $output .= $piece; + } + else { + $output .= _theme('diff_inline_chunk', array('text' => $piece, 'type' => $chunk->type)); + } + } + break; + } + } + return $output; + } + + /** + * Merge chunk segments between tag delimiters. + */ + function process_chunk($chunk) { + $processed = array(); + $j = 0; + foreach ($chunk as $i => $piece) { + $next = isset($chunk[$i+1]) ? $chunk[$i+1] : NULL; + if (!isset($processed[$j])) { + $processed[$j] = ''; + } + if (strpos($piece, '<') === 0 && drupal_substr($piece, drupal_strlen($piece) - 1) === '>') { + $processed[$j] = $piece; + $j++; + } + elseif (isset($next) && strpos($next, '<') === 0 && drupal_substr($next, drupal_strlen($next) - 1) === '>') { + $processed[$j] .= $piece; + $j++; + } + else { + $processed[$j] .= $piece; + } + } + return $processed; + } + + /** + * Merge copy and equivalent edits into intelligible chunks. + */ + function process_edits($edits) { + $processed = array(); + $current = array_shift($edits); + + // Make two passes -- first merge space delimiter copies back into their originals. + while ($chunk = array_shift($edits)) { + if ($chunk->type == 'copy' && $chunk->orig === array(' ')) { + $current->orig = array_merge((array) $current->orig, (array) $chunk->orig); + $current->closing = array_merge((array) $current->closing, (array) $chunk->closing); + } + else { + $processed[] = $current; + $current = $chunk; + } + } + $processed[] = $current; + + // Initial setup + $edits = $processed; + $processed = array(); + $current = array_shift($edits); + + // Second, merge equivalent chunks into each other. + while ($chunk = array_shift($edits)) { + if ($current->type == $chunk->type) { + $current->orig = array_merge((array) $current->orig, (array) $chunk->orig); + $current->closing = array_merge((array) $current->closing, (array) $chunk->closing); + } + else { + $processed[] = $current; + $current = $chunk; + } + } + $processed[] = $current; + + return $processed; + } +} diff --git a/src/DrupalDiffFormatter.php b/src/DrupalDiffFormatter.php new file mode 100644 index 0000000..f0c0d51 --- /dev/null +++ b/src/DrupalDiffFormatter.php @@ -0,0 +1,1355 @@ + + * You may copy this code freely under the conditions of the GPL. + */ + +define('USE_ASSERTS', FALSE); + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp { + var $type; + var $orig; + var $closing; + + function reverse() { + trigger_error('pure virtual', E_USER_ERROR); + } + + function norig() { + return $this->orig ? sizeof($this->orig) : 0; + } + + function nclosing() { + return $this->closing ? sizeof($this->closing) : 0; + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Copy extends _DiffOp { + var $type = 'copy'; + + function _DiffOp_Copy($orig, $closing = FALSE) { + if (!is_array($closing)) { + $closing = $orig; + } + $this->orig = $orig; + $this->closing = $closing; + } + + function reverse() { + return new _DiffOp_Copy($this->closing, $this->orig); + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Delete extends _DiffOp { + var $type = 'delete'; + + function _DiffOp_Delete($lines) { + $this->orig = $lines; + $this->closing = FALSE; + } + + function reverse() { + return new _DiffOp_Add($this->orig); + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Add extends _DiffOp { + var $type = 'add'; + + function _DiffOp_Add($lines) { + $this->closing = $lines; + $this->orig = FALSE; + } + + function reverse() { + return new _DiffOp_Delete($this->closing); + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Change extends _DiffOp { + var $type = 'change'; + + function _DiffOp_Change($orig, $closing) { + $this->orig = $orig; + $this->closing = $closing; + } + + function reverse() { + return new _DiffOp_Change($this->closing, $this->orig); + } +} + + +/** + * Class used internally by Diff to actually compute the diffs. + * + * The algorithm used here is mostly lifted from the perl module + * Algorithm::Diff (version 1.06) by Ned Konz, which is available at: + * http://www.perl.com/CPAN/authors/id/N/NE/NEDKONZ/Algorithm-Diff-1.06.zip + * + * More ideas are taken from: + * http://www.ics.uci.edu/~eppstein/161/960229.html + * + * Some ideas are (and a bit of code) are from from analyze.c, from GNU + * diffutils-2.7, which can be found at: + * ftp://gnudist.gnu.org/pub/gnu/diffutils/diffutils-2.7.tar.gz + * + * closingly, some ideas (subdivision by NCHUNKS > 2, and some optimizations) + * are my own. + * + * Line length limits for robustness added by Tim Starling, 2005-08-31 + * + * @author Geoffrey T. Dairiki, Tim Starling + * @private + * @subpackage DifferenceEngine + */ +class _DiffEngine { + function MAX_XREF_LENGTH() { + return 10000; + } + + function diff($from_lines, $to_lines) { + + $n_from = sizeof($from_lines); + $n_to = sizeof($to_lines); + + $this->xchanged = $this->ychanged = array(); + $this->xv = $this->yv = array(); + $this->xind = $this->yind = array(); + unset($this->seq); + unset($this->in_seq); + unset($this->lcs); + + // Skip leading common lines. + for ($skip = 0; $skip < $n_from && $skip < $n_to; $skip++) { + if ($from_lines[$skip] !== $to_lines[$skip]) { + break; + } + $this->xchanged[$skip] = $this->ychanged[$skip] = FALSE; + } + // Skip trailing common lines. + $xi = $n_from; + $yi = $n_to; + for ($endskip = 0; --$xi > $skip && --$yi > $skip; $endskip++) { + if ($from_lines[$xi] !== $to_lines[$yi]) { + break; + } + $this->xchanged[$xi] = $this->ychanged[$yi] = FALSE; + } + + // Ignore lines which do not exist in both files. + for ($xi = $skip; $xi < $n_from - $endskip; $xi++) { + $xhash[$this->_line_hash($from_lines[$xi])] = 1; + } + + for ($yi = $skip; $yi < $n_to - $endskip; $yi++) { + $line = $to_lines[$yi]; + if ($this->ychanged[$yi] = empty($xhash[$this->_line_hash($line)])) { + continue; + } + $yhash[$this->_line_hash($line)] = 1; + $this->yv[] = $line; + $this->yind[] = $yi; + } + for ($xi = $skip; $xi < $n_from - $endskip; $xi++) { + $line = $from_lines[$xi]; + if ($this->xchanged[$xi] = empty($yhash[$this->_line_hash($line)])) { + continue; + } + $this->xv[] = $line; + $this->xind[] = $xi; + } + + // Find the LCS. + $this->_compareseq(0, sizeof($this->xv), 0, sizeof($this->yv)); + + // Merge edits when possible + $this->_shift_boundaries($from_lines, $this->xchanged, $this->ychanged); + $this->_shift_boundaries($to_lines, $this->ychanged, $this->xchanged); + + // Compute the edit operations. + $edits = array(); + $xi = $yi = 0; + while ($xi < $n_from || $yi < $n_to) { + USE_ASSERTS && assert($yi < $n_to || $this->xchanged[$xi]); + USE_ASSERTS && assert($xi < $n_from || $this->ychanged[$yi]); + + // Skip matching "snake". + $copy = array(); + while ( $xi < $n_from && $yi < $n_to && !$this->xchanged[$xi] && !$this->ychanged[$yi]) { + $copy[] = $from_lines[$xi++]; + ++$yi; + } + if ($copy) { + $edits[] = new _DiffOp_Copy($copy); + } + // Find deletes & adds. + $delete = array(); + while ($xi < $n_from && $this->xchanged[$xi]) { + $_fl = $from_lines[$xi++]; + if (strlen($_fl)) { + $delete[] = $_fl; + } + } + $add = array(); + while ($yi < $n_to && $this->ychanged[$yi]) { + $_tl = $to_lines[$yi++]; + if (strlen($_tl)) { + $add[] = $_tl; + } + } + if ($delete && $add) { + $edits[] = new _DiffOp_Change($delete, $add); + } + elseif ($delete) { + $edits[] = new _DiffOp_Delete($delete); + } + elseif ($add) { + $edits[] = new _DiffOp_Add($add); + } + } + return $edits; + } + + /** + * Returns the whole line if it's small enough, or the MD5 hash otherwise. + */ + function _line_hash($line) { + if (drupal_strlen($line) > $this->MAX_XREF_LENGTH()) { + return md5($line); + } + else { + return $line; + } + } + + + /** + * Divide the Largest Common Subsequence (LCS) of the sequences + * [XOFF, XLIM) and [YOFF, YLIM) into NCHUNKS approximately equally + * sized segments. + * + * Returns (LCS, PTS). LCS is the length of the LCS. PTS is an + * array of NCHUNKS+1 (X, Y) indexes giving the diving points between + * sub sequences. The first sub-sequence is contained in [X0, X1), + * [Y0, Y1), the second in [X1, X2), [Y1, Y2) and so on. Note + * that (X0, Y0) == (XOFF, YOFF) and + * (X[NCHUNKS], Y[NCHUNKS]) == (XLIM, YLIM). + * + * This function assumes that the first lines of the specified portions + * of the two files do not match, and likewise that the last lines do not + * match. The caller must trim matching lines from the beginning and end + * of the portions it is going to specify. + */ + function _diag($xoff, $xlim, $yoff, $ylim, $nchunks) { + $flip = FALSE; + + if ($xlim - $xoff > $ylim - $yoff) { + // Things seems faster (I'm not sure I understand why) + // when the shortest sequence in X. + $flip = TRUE; + list($xoff, $xlim, $yoff, $ylim) = array($yoff, $ylim, $xoff, $xlim); + } + + if ($flip) { + for ($i = $ylim - 1; $i >= $yoff; $i--) { + $ymatches[$this->xv[$i]][] = $i; + } + } + else { + for ($i = $ylim - 1; $i >= $yoff; $i--) { + $ymatches[$this->yv[$i]][] = $i; + } + } + $this->lcs = 0; + $this->seq[0]= $yoff - 1; + $this->in_seq = array(); + $ymids[0] = array(); + + $numer = $xlim - $xoff + $nchunks - 1; + $x = $xoff; + for ($chunk = 0; $chunk < $nchunks; $chunk++) { + if ($chunk > 0) { + for ($i = 0; $i <= $this->lcs; $i++) { + $ymids[$i][$chunk-1] = $this->seq[$i]; + } + } + + $x1 = $xoff + (int)(($numer + ($xlim-$xoff)*$chunk) / $nchunks); + for ( ; $x < $x1; $x++) { + $line = $flip ? $this->yv[$x] : $this->xv[$x]; + if (empty($ymatches[$line])) { + continue; + } + $matches = $ymatches[$line]; + reset($matches); + while (list ($junk, $y) = each($matches)) { + if (empty($this->in_seq[$y])) { + $k = $this->_lcs_pos($y); + USE_ASSERTS && assert($k > 0); + $ymids[$k] = $ymids[$k-1]; + break; + } + } + while (list ($junk, $y) = each($matches)) { + if ($y > $this->seq[$k-1]) { + USE_ASSERTS && assert($y < $this->seq[$k]); + // Optimization: this is a common case: + // next match is just replacing previous match. + $this->in_seq[$this->seq[$k]] = FALSE; + $this->seq[$k] = $y; + $this->in_seq[$y] = 1; + } + elseif (empty($this->in_seq[$y])) { + $k = $this->_lcs_pos($y); + USE_ASSERTS && assert($k > 0); + $ymids[$k] = $ymids[$k-1]; + } + } + } + } + + $seps[] = $flip ? array($yoff, $xoff) : array($xoff, $yoff); + $ymid = $ymids[$this->lcs]; + for ($n = 0; $n < $nchunks - 1; $n++) { + $x1 = $xoff + (int)(($numer + ($xlim - $xoff) * $n) / $nchunks); + $y1 = $ymid[$n] + 1; + $seps[] = $flip ? array($y1, $x1) : array($x1, $y1); + } + $seps[] = $flip ? array($ylim, $xlim) : array($xlim, $ylim); + + return array($this->lcs, $seps); + } + + function _lcs_pos($ypos) { + + $end = $this->lcs; + if ($end == 0 || $ypos > $this->seq[$end]) { + $this->seq[++$this->lcs] = $ypos; + $this->in_seq[$ypos] = 1; + return $this->lcs; + } + + $beg = 1; + while ($beg < $end) { + $mid = (int)(($beg + $end) / 2); + if ($ypos > $this->seq[$mid]) { + $beg = $mid + 1; + } + else { + $end = $mid; + } + } + + USE_ASSERTS && assert($ypos != $this->seq[$end]); + + $this->in_seq[$this->seq[$end]] = FALSE; + $this->seq[$end] = $ypos; + $this->in_seq[$ypos] = 1; + return $end; + } + + /** + * Find LCS of two sequences. + * + * The results are recorded in the vectors $this->{x,y}changed[], by + * storing a 1 in the element for each line that is an insertion + * or deletion (ie. is not in the LCS). + * + * The subsequence of file 0 is [XOFF, XLIM) and likewise for file 1. + * + * Note that XLIM, YLIM are exclusive bounds. + * All line numbers are origin-0 and discarded lines are not counted. + */ + function _compareseq($xoff, $xlim, $yoff, $ylim) { + + // Slide down the bottom initial diagonal. + while ($xoff < $xlim && $yoff < $ylim && $this->xv[$xoff] == $this->yv[$yoff]) { + ++$xoff; + ++$yoff; + } + + // Slide up the top initial diagonal. + while ($xlim > $xoff && $ylim > $yoff && $this->xv[$xlim - 1] == $this->yv[$ylim - 1]) { + --$xlim; + --$ylim; + } + + if ($xoff == $xlim || $yoff == $ylim) { + $lcs = 0; + } + else { + // This is ad hoc but seems to work well. + //$nchunks = sqrt(min($xlim - $xoff, $ylim - $yoff) / 2.5); + //$nchunks = max(2, min(8, (int)$nchunks)); + $nchunks = min(7, $xlim - $xoff, $ylim - $yoff) + 1; + list($lcs, $seps) + = $this->_diag($xoff, $xlim, $yoff, $ylim, $nchunks); + } + + if ($lcs == 0) { + // X and Y sequences have no common subsequence: + // mark all changed. + while ($yoff < $ylim) { + $this->ychanged[$this->yind[$yoff++]] = 1; + } + while ($xoff < $xlim) { + $this->xchanged[$this->xind[$xoff++]] = 1; + } + } + else { + // Use the partitions to split this problem into subproblems. + reset($seps); + $pt1 = $seps[0]; + while ($pt2 = next($seps)) { + $this->_compareseq ($pt1[0], $pt2[0], $pt1[1], $pt2[1]); + $pt1 = $pt2; + } + } + } + + /** + * Adjust inserts/deletes of identical lines to join changes + * as much as possible. + * + * We do something when a run of changed lines include a + * line at one end and has an excluded, identical line at the other. + * We are free to choose which identical line is included. + * `compareseq' usually chooses the one at the beginning, + * but usually it is cleaner to consider the following identical line + * to be the "change". + * + * This is extracted verbatim from analyze.c (GNU diffutils-2.7). + */ + function _shift_boundaries($lines, &$changed, $other_changed) { + $i = 0; + $j = 0; + + USE_ASSERTS && assert('sizeof($lines) == sizeof($changed)'); + $len = sizeof($lines); + $other_len = sizeof($other_changed); + + while (1) { + /* + * Scan forwards to find beginning of another run of changes. + * Also keep track of the corresponding point in the other file. + * + * Throughout this code, $i and $j are adjusted together so that + * the first $i elements of $changed and the first $j elements + * of $other_changed both contain the same number of zeros + * (unchanged lines). + * Furthermore, $j is always kept so that $j == $other_len or + * $other_changed[$j] == FALSE. + */ + while ($j < $other_len && $other_changed[$j]) { + $j++; + } + while ($i < $len && ! $changed[$i]) { + USE_ASSERTS && assert('$j < $other_len && ! $other_changed[$j]'); + $i++; + $j++; + while ($j < $other_len && $other_changed[$j]) { + $j++; + } + } + + if ($i == $len) { + break; + } + $start = $i; + + // Find the end of this run of changes. + while (++$i < $len && $changed[$i]) { + continue; + } + + do { + /* + * Record the length of this run of changes, so that + * we can later determine whether the run has grown. + */ + $runlength = $i - $start; + + /* + * Move the changed region back, so long as the + * previous unchanged line matches the last changed one. + * This merges with previous changed regions. + */ + while ($start > 0 && $lines[$start - 1] == $lines[$i - 1]) { + $changed[--$start] = 1; + $changed[--$i] = FALSE; + while ($start > 0 && $changed[$start - 1]) { + $start--; + } + USE_ASSERTS && assert('$j > 0'); + while ($other_changed[--$j]) { + continue; + } + USE_ASSERTS && assert('$j >= 0 && !$other_changed[$j]'); + } + + /* + * Set CORRESPONDING to the end of the changed run, at the last + * point where it corresponds to a changed run in the other file. + * CORRESPONDING == LEN means no such point has been found. + */ + $corresponding = $j < $other_len ? $i : $len; + + /* + * Move the changed region forward, so long as the + * first changed line matches the following unchanged one. + * This merges with following changed regions. + * Do this second, so that if there are no merges, + * the changed region is moved forward as far as possible. + */ + while ($i < $len && $lines[$start] == $lines[$i]) { + $changed[$start++] = FALSE; + $changed[$i++] = 1; + while ($i < $len && $changed[$i]) { + $i++; + } + USE_ASSERTS && assert('$j < $other_len && ! $other_changed[$j]'); + $j++; + if ($j < $other_len && $other_changed[$j]) { + $corresponding = $i; + while ($j < $other_len && $other_changed[$j]) { + $j++; + } + } + } + } while ($runlength != $i - $start); + + /* + * If possible, move the fully-merged run of changes + * back to a corresponding run in the other file. + */ + while ($corresponding < $i) { + $changed[--$start] = 1; + $changed[--$i] = 0; + USE_ASSERTS && assert('$j > 0'); + while ($other_changed[--$j]) { + continue; + } + USE_ASSERTS && assert('$j >= 0 && !$other_changed[$j]'); + } + } + } +} + +/** + * Class representing a 'diff' between two sequences of strings. + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class Diff { + var $edits; + + /** + * Constructor. + * Computes diff between sequences of strings. + * + * @param $from_lines array An array of strings. + * (Typically these are lines from a file.) + * @param $to_lines array An array of strings. + */ + function Diff($from_lines, $to_lines) { + $eng = new _DiffEngine; + $this->edits = $eng->diff($from_lines, $to_lines); + //$this->_check($from_lines, $to_lines); + } + + /** + * Compute reversed Diff. + * + * SYNOPSIS: + * + * $diff = new Diff($lines1, $lines2); + * $rev = $diff->reverse(); + * @return object A Diff object representing the inverse of the + * original diff. + */ + function reverse() { + $rev = $this; + $rev->edits = array(); + foreach ($this->edits as $edit) { + $rev->edits[] = $edit->reverse(); + } + return $rev; + } + + /** + * Check for empty diff. + * + * @return bool True iff two sequences were identical. + */ + function isEmpty() { + foreach ($this->edits as $edit) { + if ($edit->type != 'copy') { + return FALSE; + } + } + return TRUE; + } + + /** + * Compute the length of the Longest Common Subsequence (LCS). + * + * This is mostly for diagnostic purposed. + * + * @return int The length of the LCS. + */ + function lcs() { + $lcs = 0; + foreach ($this->edits as $edit) { + if ($edit->type == 'copy') { + $lcs += sizeof($edit->orig); + } + } + return $lcs; + } + + /** + * Get the original set of lines. + * + * This reconstructs the $from_lines parameter passed to the + * constructor. + * + * @return array The original sequence of strings. + */ + function orig() { + $lines = array(); + + foreach ($this->edits as $edit) { + if ($edit->orig) { + array_splice($lines, sizeof($lines), 0, $edit->orig); + } + } + return $lines; + } + + /** + * Get the closing set of lines. + * + * This reconstructs the $to_lines parameter passed to the + * constructor. + * + * @return array The sequence of strings. + */ + function closing() { + $lines = array(); + + foreach ($this->edits as $edit) { + if ($edit->closing) { + array_splice($lines, sizeof($lines), 0, $edit->closing); + } + } + return $lines; + } + + /** + * Check a Diff for validity. + * + * This is here only for debugging purposes. + */ + function _check($from_lines, $to_lines) { + if (serialize($from_lines) != serialize($this->orig())) { + trigger_error("Reconstructed original doesn't match", E_USER_ERROR); + } + if (serialize($to_lines) != serialize($this->closing())) { + trigger_error("Reconstructed closing doesn't match", E_USER_ERROR); + } + + $rev = $this->reverse(); + if (serialize($to_lines) != serialize($rev->orig())) { + trigger_error("Reversed original doesn't match", E_USER_ERROR); + } + if (serialize($from_lines) != serialize($rev->closing())) { + trigger_error("Reversed closing doesn't match", E_USER_ERROR); + } + + + $prevtype = 'none'; + foreach ($this->edits as $edit) { + if ( $prevtype == $edit->type ) { + trigger_error("Edit sequence is non-optimal", E_USER_ERROR); + } + $prevtype = $edit->type; + } + + $lcs = $this->lcs(); + trigger_error('Diff okay: LCS = ' . $lcs, E_USER_NOTICE); + } +} + +/** + * FIXME: bad name. + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class MappedDiff extends Diff { + /** + * Constructor. + * + * Computes diff between sequences of strings. + * + * This can be used to compute things like + * case-insensitve diffs, or diffs which ignore + * changes in white-space. + * + * @param $from_lines array An array of strings. + * (Typically these are lines from a file.) + * + * @param $to_lines array An array of strings. + * + * @param $mapped_from_lines array This array should + * have the same size number of elements as $from_lines. + * The elements in $mapped_from_lines and + * $mapped_to_lines are what is actually compared + * when computing the diff. + * + * @param $mapped_to_lines array This array should + * have the same number of elements as $to_lines. + */ + function MappedDiff($from_lines, $to_lines, $mapped_from_lines, $mapped_to_lines) { + + assert(sizeof($from_lines) == sizeof($mapped_from_lines)); + assert(sizeof($to_lines) == sizeof($mapped_to_lines)); + + $this->Diff($mapped_from_lines, $mapped_to_lines); + + $xi = $yi = 0; + for ($i = 0; $i < sizeof($this->edits); $i++) { + $orig = &$this->edits[$i]->orig; + if (is_array($orig)) { + $orig = array_slice($from_lines, $xi, sizeof($orig)); + $xi += sizeof($orig); + } + + $closing = &$this->edits[$i]->closing; + if (is_array($closing)) { + $closing = array_slice($to_lines, $yi, sizeof($closing)); + $yi += sizeof($closing); + } + } + } +} + +/** + * A class to format Diffs + * + * This class formats the diff in classic diff format. + * It is intended that this class be customized via inheritance, + * to obtain fancier outputs. + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class DiffFormatter { + /** + * Should a block header be shown? + */ + var $show_header = TRUE; + + /** + * Number of leading context "lines" to preserve. + * + * This should be left at zero for this class, but subclasses + * may want to set this to other values. + */ + var $leading_context_lines = 0; + + /** + * Number of trailing context "lines" to preserve. + * + * This should be left at zero for this class, but subclasses + * may want to set this to other values. + */ + var $trailing_context_lines = 0; + + /** + * Format a diff. + * + * @param $diff object A Diff object. + * @return string The formatted output. + */ + function format($diff) { + $xi = $yi = 1; + $block = FALSE; + $context = array(); + + $nlead = $this->leading_context_lines; + $ntrail = $this->trailing_context_lines; + + $this->_start_diff(); + + foreach ($diff->edits as $edit) { + if ($edit->type == 'copy') { + if (is_array($block)) { + if (sizeof($edit->orig) <= $nlead + $ntrail) { + $block[] = $edit; + } + else { + if ($ntrail) { + $context = array_slice($edit->orig, 0, $ntrail); + $block[] = new _DiffOp_Copy($context); + } + $this->_block($x0, $ntrail + $xi - $x0, $y0, $ntrail + $yi - $y0, $block); + $block = FALSE; + } + } + $context = $edit->orig; + } + else { + if (! is_array($block)) { + $context = array_slice($context, sizeof($context) - $nlead); + $x0 = $xi - sizeof($context); + $y0 = $yi - sizeof($context); + $block = array(); + if ($context) { + $block[] = new _DiffOp_Copy($context); + } + } + $block[] = $edit; + } + + if ($edit->orig) { + $xi += sizeof($edit->orig); + } + if ($edit->closing) { + $yi += sizeof($edit->closing); + } + } + + if (is_array($block)) { + $this->_block($x0, $xi - $x0, $y0, $yi - $y0, $block); + } + $end = $this->_end_diff(); + + if (!empty($xi)) { + $this->line_stats['counter']['x'] += $xi; + } + if (!empty($yi)) { + $this->line_stats['counter']['y'] += $yi; + } + + return $end; + } + + function _block($xbeg, $xlen, $ybeg, $ylen, &$edits) { + $this->_start_block($this->_block_header($xbeg, $xlen, $ybeg, $ylen)); + foreach ($edits as $edit) { + if ($edit->type == 'copy') { + $this->_context($edit->orig); + } + elseif ($edit->type == 'add') { + $this->_added($edit->closing); + } + elseif ($edit->type == 'delete') { + $this->_deleted($edit->orig); + } + elseif ($edit->type == 'change') { + $this->_changed($edit->orig, $edit->closing); + } + else { + trigger_error('Unknown edit type', E_USER_ERROR); + } + } + $this->_end_block(); + } + + function _start_diff() { + ob_start(); + } + + function _end_diff() { + $val = ob_get_contents(); + ob_end_clean(); + return $val; + } + + function _block_header($xbeg, $xlen, $ybeg, $ylen) { + if ($xlen > 1) { + $xbeg .= "," . ($xbeg + $xlen - 1); + } + if ($ylen > 1) { + $ybeg .= "," . ($ybeg + $ylen - 1); + } + + return $xbeg . ($xlen ? ($ylen ? 'c' : 'd') : 'a') . $ybeg; + } + + function _start_block($header) { + if ($this->show_header) { + echo $header . "\n"; + } + } + + function _end_block() { + } + + function _lines($lines, $prefix = ' ') { + foreach ($lines as $line) { + echo "$prefix $line\n"; + } + } + + function _context($lines) { + $this->_lines($lines); + } + + function _added($lines) { + $this->_lines($lines, '>'); + } + function _deleted($lines) { + $this->_lines($lines, '<'); + } + + function _changed($orig, $closing) { + $this->_deleted($orig); + echo "---\n"; + $this->_added($closing); + } +} + + +/** + * Additions by Axel Boldt follow, partly taken from diff.php, phpwiki-1.3.3 + * + */ + +define('NBSP', ' '); // iso-8859-x non-breaking space. + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _HWLDF_WordAccumulator { + function _HWLDF_WordAccumulator() { + $this->_lines = array(); + $this->_line = ''; + $this->_group = ''; + $this->_tag = ''; + } + + function _flushGroup($new_tag) { + if ($this->_group !== '') { + if ($this->_tag == 'mark') { + $this->_line .= '' . check_plain($this->_group) . ''; + } + else { + $this->_line .= check_plain($this->_group); + } + } + $this->_group = ''; + $this->_tag = $new_tag; + } + + function _flushLine($new_tag) { + $this->_flushGroup($new_tag); + if ($this->_line != '') { + array_push($this->_lines, $this->_line); + } + else { + // make empty lines visible by inserting an NBSP + array_push($this->_lines, NBSP); + } + $this->_line = ''; + } + + function addWords($words, $tag = '') { + if ($tag != $this->_tag) { + $this->_flushGroup($tag); + } + foreach ($words as $word) { + // new-line should only come as first char of word. + if ($word == '') { + continue; + } + if ($word[0] == "\n") { + $this->_flushLine($tag); + $word = drupal_substr($word, 1); + } + assert(!strstr($word, "\n")); + $this->_group .= $word; + } + } + + function getLines() { + $this->_flushLine('~done'); + return $this->_lines; + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class WordLevelDiff extends MappedDiff { + function MAX_LINE_LENGTH() { + return 10000; + } + + function WordLevelDiff($orig_lines, $closing_lines) { + list($orig_words, $orig_stripped) = $this->_split($orig_lines); + list($closing_words, $closing_stripped) = $this->_split($closing_lines); + + $this->MappedDiff($orig_words, $closing_words, $orig_stripped, $closing_stripped); + } + + function _split($lines) { + $words = array(); + $stripped = array(); + $first = TRUE; + foreach ($lines as $line) { + // If the line is too long, just pretend the entire line is one big word + // This prevents resource exhaustion problems + if ( $first ) { + $first = FALSE; + } + else { + $words[] = "\n"; + $stripped[] = "\n"; + } + if ( drupal_strlen( $line ) > $this->MAX_LINE_LENGTH() ) { + $words[] = $line; + $stripped[] = $line; + } + else { + if (preg_match_all('/ ( [^\S\n]+ | [0-9_A-Za-z\x80-\xff]+ | . ) (?: (?!< \n) [^\S\n])? /xs', $line, $m)) { + $words = array_merge($words, $m[0]); + $stripped = array_merge($stripped, $m[1]); + } + } + } + return array($words, $stripped); + } + + function orig() { + $orig = new _HWLDF_WordAccumulator; + + foreach ($this->edits as $edit) { + if ($edit->type == 'copy') { + $orig->addWords($edit->orig); + } + elseif ($edit->orig) { + $orig->addWords($edit->orig, 'mark'); + } + } + $lines = $orig->getLines(); + return $lines; + } + + function closing() { + $closing = new _HWLDF_WordAccumulator; + + foreach ($this->edits as $edit) { + if ($edit->type == 'copy') { + $closing->addWords($edit->closing); + } + elseif ($edit->closing) { + $closing->addWords($edit->closing, 'mark'); + } + } + $lines = $closing->getLines(); + return $lines; + } +} + +/** + * Diff formatter which uses Drupal theme functions. + * @private + * @subpackage DifferenceEngine + */ +class DrupalDiffFormatter extends DiffFormatter { + + var $rows; + var $line_stats = array( + 'counter' => array('x' => 0, 'y' => 0), + 'offset' => array('x' => 0, 'y' => 0), + ); + + function DrupalDiffFormatter() { + $this->leading_context_lines = \Drupal::config('diff.settings')->get('diff_context_lines_leading'); + $this->trailing_context_lines = \Drupal::config('diff.settings')->get('diff_context_lines_trailing'); + } + + function _start_diff() { + $this->rows = array(); + } + + function _end_diff() { + return $this->rows; + } + + function _block_header($xbeg, $xlen, $ybeg, $ylen) { + return array( + array( + 'data' => _theme('diff_header_line', array('lineno' => $xbeg + $this->line_stats['offset']['x'])), + 'colspan' => 2, + ), + array( + 'data' => _theme('diff_header_line', array('lineno' => $ybeg + $this->line_stats['offset']['y'])), + 'colspan' => 2, + ) + ); + } + + function _start_block($header) { + if ($this->show_header) { + $this->rows[] = $header; + } + } + + function _end_block() { + } + + function _lines($lines, $prefix=' ', $color='white') { + } + + /** + * Note: you should HTML-escape parameter before calling this. + */ + function addedLine($line) { + return array( + array( + 'data' => '+', + 'class' => 'diff-marker', + ), + array( + 'data' => _theme('diff_content_line', array('line' => $line)), + 'class' => 'diff-context diff-addedline', + ) + ); + } + + /** + * Note: you should HTML-escape parameter before calling this. + */ + function deletedLine($line) { + return array( + array( + 'data' => '-', + 'class' => 'diff-marker', + ), + array( + 'data' => _theme('diff_content_line', array('line' => $line)), + 'class' => 'diff-context diff-deletedline', + ) + ); + } + + /** + * Note: you should HTML-escape parameter before calling this. + */ + function contextLine($line) { + return array( + ' ', + array( + 'data' => _theme('diff_content_line', array('line' => $line)), + 'class' => 'diff-context', + ) + ); + } + + function emptyLine() { + return array( + ' ', + _theme('diff_empty_line', array('line' => ' ')), + ); + } + + function _added($lines) { + foreach ($lines as $line) { + $this->rows[] = array_merge($this->emptyLine(), $this->addedLine(check_plain($line))); + } + } + + function _deleted($lines) { + foreach ($lines as $line) { + $this->rows[] = array_merge($this->deletedLine(check_plain($line)), $this->emptyLine()); + } + } + + function _context($lines) { + foreach ($lines as $line) { + $this->rows[] = array_merge($this->contextLine(check_plain($line)), $this->contextLine(check_plain($line))); + } + } + + function _changed($orig, $closing) { + $diff = new WordLevelDiff($orig, $closing); + $del = $diff->orig(); + $add = $diff->closing(); + + // Notice that WordLevelDiff returns HTML-escaped output. + // Hence, we will be calling addedLine/deletedLine without HTML-escaping. + + while ($line = array_shift($del)) { + $aline = array_shift( $add ); + $this->rows[] = array_merge($this->deletedLine($line), isset($aline) ? $this->addedLine($aline) : $this->emptyLine()); + } + foreach ($add as $line) { // If any leftovers + $this->rows[] = array_merge($this->emptyLine(), $this->addedLine($line)); + } + } +} + +/** + * Drupal inline Diff formatter. + * @private + * @subpackage DifferenceEngine + */ +class DrupalDiffInline { + var $a; + var $b; + + /** + * Constructor. + */ + function __construct($a, $b) { + $this->a = $a; + $this->b = $b; + } + + /** + * Render differences inline using HTML markup. + */ + function render() { + $a = preg_split('/(<[^>]+?>| )/', $this->a, -1, PREG_SPLIT_DELIM_CAPTURE); + $b = preg_split('/(<[^>]+?>| )/', $this->b, -1, PREG_SPLIT_DELIM_CAPTURE); + $diff = new Diff($a, $b); + $diff->edits = $this->process_edits($diff->edits); + + // Assemble highlighted output + $output = ''; + foreach ($diff->edits as $chunk) { + switch ($chunk->type) { + case 'copy': + $output .= implode('', $chunk->closing); + break; + case 'delete': + foreach ($chunk->orig as $i => $piece) { + if (strpos($piece, '<') === 0 && drupal_substr($piece, drupal_strlen($piece) - 1) === '>') { + $output .= $piece; + } + else { + $output .= _theme('diff_inline_chunk', array('text' => $piece, 'type' => $chunk->type)); + } + } + break; + default: + $chunk->closing = $this->process_chunk($chunk->closing); + foreach ($chunk->closing as $i => $piece) { + if ($piece === ' ' || (strpos($piece, '<') === 0 && drupal_substr($piece, drupal_strlen($piece) - 1) === '>' && drupal_strtolower(drupal_substr($piece, 1, 3)) != 'img')) { + $output .= $piece; + } + else { + $output .= _theme('diff_inline_chunk', array('text' => $piece, 'type' => $chunk->type)); + } + } + break; + } + } + return $output; + } + + /** + * Merge chunk segments between tag delimiters. + */ + function process_chunk($chunk) { + $processed = array(); + $j = 0; + foreach ($chunk as $i => $piece) { + $next = isset($chunk[$i+1]) ? $chunk[$i+1] : NULL; + if (!isset($processed[$j])) { + $processed[$j] = ''; + } + if (strpos($piece, '<') === 0 && drupal_substr($piece, drupal_strlen($piece) - 1) === '>') { + $processed[$j] = $piece; + $j++; + } + elseif (isset($next) && strpos($next, '<') === 0 && drupal_substr($next, drupal_strlen($next) - 1) === '>') { + $processed[$j] .= $piece; + $j++; + } + else { + $processed[$j] .= $piece; + } + } + return $processed; + } + + /** + * Merge copy and equivalent edits into intelligible chunks. + */ + function process_edits($edits) { + $processed = array(); + $current = array_shift($edits); + + // Make two passes -- first merge space delimiter copies back into their originals. + while ($chunk = array_shift($edits)) { + if ($chunk->type == 'copy' && $chunk->orig === array(' ')) { + $current->orig = array_merge((array) $current->orig, (array) $chunk->orig); + $current->closing = array_merge((array) $current->closing, (array) $chunk->closing); + } + else { + $processed[] = $current; + $current = $chunk; + } + } + $processed[] = $current; + + // Initial setup + $edits = $processed; + $processed = array(); + $current = array_shift($edits); + + // Second, merge equivalent chunks into each other. + while ($chunk = array_shift($edits)) { + if ($current->type == $chunk->type) { + $current->orig = array_merge((array) $current->orig, (array) $chunk->orig); + $current->closing = array_merge((array) $current->closing, (array) $chunk->closing); + } + else { + $processed[] = $current; + $current = $chunk; + } + } + $processed[] = $current; + + return $processed; + } +} diff --git a/src/DrupalDiffInline.php b/src/DrupalDiffInline.php new file mode 100644 index 0000000..f0c0d51 --- /dev/null +++ b/src/DrupalDiffInline.php @@ -0,0 +1,1355 @@ + + * You may copy this code freely under the conditions of the GPL. + */ + +define('USE_ASSERTS', FALSE); + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp { + var $type; + var $orig; + var $closing; + + function reverse() { + trigger_error('pure virtual', E_USER_ERROR); + } + + function norig() { + return $this->orig ? sizeof($this->orig) : 0; + } + + function nclosing() { + return $this->closing ? sizeof($this->closing) : 0; + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Copy extends _DiffOp { + var $type = 'copy'; + + function _DiffOp_Copy($orig, $closing = FALSE) { + if (!is_array($closing)) { + $closing = $orig; + } + $this->orig = $orig; + $this->closing = $closing; + } + + function reverse() { + return new _DiffOp_Copy($this->closing, $this->orig); + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Delete extends _DiffOp { + var $type = 'delete'; + + function _DiffOp_Delete($lines) { + $this->orig = $lines; + $this->closing = FALSE; + } + + function reverse() { + return new _DiffOp_Add($this->orig); + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Add extends _DiffOp { + var $type = 'add'; + + function _DiffOp_Add($lines) { + $this->closing = $lines; + $this->orig = FALSE; + } + + function reverse() { + return new _DiffOp_Delete($this->closing); + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Change extends _DiffOp { + var $type = 'change'; + + function _DiffOp_Change($orig, $closing) { + $this->orig = $orig; + $this->closing = $closing; + } + + function reverse() { + return new _DiffOp_Change($this->closing, $this->orig); + } +} + + +/** + * Class used internally by Diff to actually compute the diffs. + * + * The algorithm used here is mostly lifted from the perl module + * Algorithm::Diff (version 1.06) by Ned Konz, which is available at: + * http://www.perl.com/CPAN/authors/id/N/NE/NEDKONZ/Algorithm-Diff-1.06.zip + * + * More ideas are taken from: + * http://www.ics.uci.edu/~eppstein/161/960229.html + * + * Some ideas are (and a bit of code) are from from analyze.c, from GNU + * diffutils-2.7, which can be found at: + * ftp://gnudist.gnu.org/pub/gnu/diffutils/diffutils-2.7.tar.gz + * + * closingly, some ideas (subdivision by NCHUNKS > 2, and some optimizations) + * are my own. + * + * Line length limits for robustness added by Tim Starling, 2005-08-31 + * + * @author Geoffrey T. Dairiki, Tim Starling + * @private + * @subpackage DifferenceEngine + */ +class _DiffEngine { + function MAX_XREF_LENGTH() { + return 10000; + } + + function diff($from_lines, $to_lines) { + + $n_from = sizeof($from_lines); + $n_to = sizeof($to_lines); + + $this->xchanged = $this->ychanged = array(); + $this->xv = $this->yv = array(); + $this->xind = $this->yind = array(); + unset($this->seq); + unset($this->in_seq); + unset($this->lcs); + + // Skip leading common lines. + for ($skip = 0; $skip < $n_from && $skip < $n_to; $skip++) { + if ($from_lines[$skip] !== $to_lines[$skip]) { + break; + } + $this->xchanged[$skip] = $this->ychanged[$skip] = FALSE; + } + // Skip trailing common lines. + $xi = $n_from; + $yi = $n_to; + for ($endskip = 0; --$xi > $skip && --$yi > $skip; $endskip++) { + if ($from_lines[$xi] !== $to_lines[$yi]) { + break; + } + $this->xchanged[$xi] = $this->ychanged[$yi] = FALSE; + } + + // Ignore lines which do not exist in both files. + for ($xi = $skip; $xi < $n_from - $endskip; $xi++) { + $xhash[$this->_line_hash($from_lines[$xi])] = 1; + } + + for ($yi = $skip; $yi < $n_to - $endskip; $yi++) { + $line = $to_lines[$yi]; + if ($this->ychanged[$yi] = empty($xhash[$this->_line_hash($line)])) { + continue; + } + $yhash[$this->_line_hash($line)] = 1; + $this->yv[] = $line; + $this->yind[] = $yi; + } + for ($xi = $skip; $xi < $n_from - $endskip; $xi++) { + $line = $from_lines[$xi]; + if ($this->xchanged[$xi] = empty($yhash[$this->_line_hash($line)])) { + continue; + } + $this->xv[] = $line; + $this->xind[] = $xi; + } + + // Find the LCS. + $this->_compareseq(0, sizeof($this->xv), 0, sizeof($this->yv)); + + // Merge edits when possible + $this->_shift_boundaries($from_lines, $this->xchanged, $this->ychanged); + $this->_shift_boundaries($to_lines, $this->ychanged, $this->xchanged); + + // Compute the edit operations. + $edits = array(); + $xi = $yi = 0; + while ($xi < $n_from || $yi < $n_to) { + USE_ASSERTS && assert($yi < $n_to || $this->xchanged[$xi]); + USE_ASSERTS && assert($xi < $n_from || $this->ychanged[$yi]); + + // Skip matching "snake". + $copy = array(); + while ( $xi < $n_from && $yi < $n_to && !$this->xchanged[$xi] && !$this->ychanged[$yi]) { + $copy[] = $from_lines[$xi++]; + ++$yi; + } + if ($copy) { + $edits[] = new _DiffOp_Copy($copy); + } + // Find deletes & adds. + $delete = array(); + while ($xi < $n_from && $this->xchanged[$xi]) { + $_fl = $from_lines[$xi++]; + if (strlen($_fl)) { + $delete[] = $_fl; + } + } + $add = array(); + while ($yi < $n_to && $this->ychanged[$yi]) { + $_tl = $to_lines[$yi++]; + if (strlen($_tl)) { + $add[] = $_tl; + } + } + if ($delete && $add) { + $edits[] = new _DiffOp_Change($delete, $add); + } + elseif ($delete) { + $edits[] = new _DiffOp_Delete($delete); + } + elseif ($add) { + $edits[] = new _DiffOp_Add($add); + } + } + return $edits; + } + + /** + * Returns the whole line if it's small enough, or the MD5 hash otherwise. + */ + function _line_hash($line) { + if (drupal_strlen($line) > $this->MAX_XREF_LENGTH()) { + return md5($line); + } + else { + return $line; + } + } + + + /** + * Divide the Largest Common Subsequence (LCS) of the sequences + * [XOFF, XLIM) and [YOFF, YLIM) into NCHUNKS approximately equally + * sized segments. + * + * Returns (LCS, PTS). LCS is the length of the LCS. PTS is an + * array of NCHUNKS+1 (X, Y) indexes giving the diving points between + * sub sequences. The first sub-sequence is contained in [X0, X1), + * [Y0, Y1), the second in [X1, X2), [Y1, Y2) and so on. Note + * that (X0, Y0) == (XOFF, YOFF) and + * (X[NCHUNKS], Y[NCHUNKS]) == (XLIM, YLIM). + * + * This function assumes that the first lines of the specified portions + * of the two files do not match, and likewise that the last lines do not + * match. The caller must trim matching lines from the beginning and end + * of the portions it is going to specify. + */ + function _diag($xoff, $xlim, $yoff, $ylim, $nchunks) { + $flip = FALSE; + + if ($xlim - $xoff > $ylim - $yoff) { + // Things seems faster (I'm not sure I understand why) + // when the shortest sequence in X. + $flip = TRUE; + list($xoff, $xlim, $yoff, $ylim) = array($yoff, $ylim, $xoff, $xlim); + } + + if ($flip) { + for ($i = $ylim - 1; $i >= $yoff; $i--) { + $ymatches[$this->xv[$i]][] = $i; + } + } + else { + for ($i = $ylim - 1; $i >= $yoff; $i--) { + $ymatches[$this->yv[$i]][] = $i; + } + } + $this->lcs = 0; + $this->seq[0]= $yoff - 1; + $this->in_seq = array(); + $ymids[0] = array(); + + $numer = $xlim - $xoff + $nchunks - 1; + $x = $xoff; + for ($chunk = 0; $chunk < $nchunks; $chunk++) { + if ($chunk > 0) { + for ($i = 0; $i <= $this->lcs; $i++) { + $ymids[$i][$chunk-1] = $this->seq[$i]; + } + } + + $x1 = $xoff + (int)(($numer + ($xlim-$xoff)*$chunk) / $nchunks); + for ( ; $x < $x1; $x++) { + $line = $flip ? $this->yv[$x] : $this->xv[$x]; + if (empty($ymatches[$line])) { + continue; + } + $matches = $ymatches[$line]; + reset($matches); + while (list ($junk, $y) = each($matches)) { + if (empty($this->in_seq[$y])) { + $k = $this->_lcs_pos($y); + USE_ASSERTS && assert($k > 0); + $ymids[$k] = $ymids[$k-1]; + break; + } + } + while (list ($junk, $y) = each($matches)) { + if ($y > $this->seq[$k-1]) { + USE_ASSERTS && assert($y < $this->seq[$k]); + // Optimization: this is a common case: + // next match is just replacing previous match. + $this->in_seq[$this->seq[$k]] = FALSE; + $this->seq[$k] = $y; + $this->in_seq[$y] = 1; + } + elseif (empty($this->in_seq[$y])) { + $k = $this->_lcs_pos($y); + USE_ASSERTS && assert($k > 0); + $ymids[$k] = $ymids[$k-1]; + } + } + } + } + + $seps[] = $flip ? array($yoff, $xoff) : array($xoff, $yoff); + $ymid = $ymids[$this->lcs]; + for ($n = 0; $n < $nchunks - 1; $n++) { + $x1 = $xoff + (int)(($numer + ($xlim - $xoff) * $n) / $nchunks); + $y1 = $ymid[$n] + 1; + $seps[] = $flip ? array($y1, $x1) : array($x1, $y1); + } + $seps[] = $flip ? array($ylim, $xlim) : array($xlim, $ylim); + + return array($this->lcs, $seps); + } + + function _lcs_pos($ypos) { + + $end = $this->lcs; + if ($end == 0 || $ypos > $this->seq[$end]) { + $this->seq[++$this->lcs] = $ypos; + $this->in_seq[$ypos] = 1; + return $this->lcs; + } + + $beg = 1; + while ($beg < $end) { + $mid = (int)(($beg + $end) / 2); + if ($ypos > $this->seq[$mid]) { + $beg = $mid + 1; + } + else { + $end = $mid; + } + } + + USE_ASSERTS && assert($ypos != $this->seq[$end]); + + $this->in_seq[$this->seq[$end]] = FALSE; + $this->seq[$end] = $ypos; + $this->in_seq[$ypos] = 1; + return $end; + } + + /** + * Find LCS of two sequences. + * + * The results are recorded in the vectors $this->{x,y}changed[], by + * storing a 1 in the element for each line that is an insertion + * or deletion (ie. is not in the LCS). + * + * The subsequence of file 0 is [XOFF, XLIM) and likewise for file 1. + * + * Note that XLIM, YLIM are exclusive bounds. + * All line numbers are origin-0 and discarded lines are not counted. + */ + function _compareseq($xoff, $xlim, $yoff, $ylim) { + + // Slide down the bottom initial diagonal. + while ($xoff < $xlim && $yoff < $ylim && $this->xv[$xoff] == $this->yv[$yoff]) { + ++$xoff; + ++$yoff; + } + + // Slide up the top initial diagonal. + while ($xlim > $xoff && $ylim > $yoff && $this->xv[$xlim - 1] == $this->yv[$ylim - 1]) { + --$xlim; + --$ylim; + } + + if ($xoff == $xlim || $yoff == $ylim) { + $lcs = 0; + } + else { + // This is ad hoc but seems to work well. + //$nchunks = sqrt(min($xlim - $xoff, $ylim - $yoff) / 2.5); + //$nchunks = max(2, min(8, (int)$nchunks)); + $nchunks = min(7, $xlim - $xoff, $ylim - $yoff) + 1; + list($lcs, $seps) + = $this->_diag($xoff, $xlim, $yoff, $ylim, $nchunks); + } + + if ($lcs == 0) { + // X and Y sequences have no common subsequence: + // mark all changed. + while ($yoff < $ylim) { + $this->ychanged[$this->yind[$yoff++]] = 1; + } + while ($xoff < $xlim) { + $this->xchanged[$this->xind[$xoff++]] = 1; + } + } + else { + // Use the partitions to split this problem into subproblems. + reset($seps); + $pt1 = $seps[0]; + while ($pt2 = next($seps)) { + $this->_compareseq ($pt1[0], $pt2[0], $pt1[1], $pt2[1]); + $pt1 = $pt2; + } + } + } + + /** + * Adjust inserts/deletes of identical lines to join changes + * as much as possible. + * + * We do something when a run of changed lines include a + * line at one end and has an excluded, identical line at the other. + * We are free to choose which identical line is included. + * `compareseq' usually chooses the one at the beginning, + * but usually it is cleaner to consider the following identical line + * to be the "change". + * + * This is extracted verbatim from analyze.c (GNU diffutils-2.7). + */ + function _shift_boundaries($lines, &$changed, $other_changed) { + $i = 0; + $j = 0; + + USE_ASSERTS && assert('sizeof($lines) == sizeof($changed)'); + $len = sizeof($lines); + $other_len = sizeof($other_changed); + + while (1) { + /* + * Scan forwards to find beginning of another run of changes. + * Also keep track of the corresponding point in the other file. + * + * Throughout this code, $i and $j are adjusted together so that + * the first $i elements of $changed and the first $j elements + * of $other_changed both contain the same number of zeros + * (unchanged lines). + * Furthermore, $j is always kept so that $j == $other_len or + * $other_changed[$j] == FALSE. + */ + while ($j < $other_len && $other_changed[$j]) { + $j++; + } + while ($i < $len && ! $changed[$i]) { + USE_ASSERTS && assert('$j < $other_len && ! $other_changed[$j]'); + $i++; + $j++; + while ($j < $other_len && $other_changed[$j]) { + $j++; + } + } + + if ($i == $len) { + break; + } + $start = $i; + + // Find the end of this run of changes. + while (++$i < $len && $changed[$i]) { + continue; + } + + do { + /* + * Record the length of this run of changes, so that + * we can later determine whether the run has grown. + */ + $runlength = $i - $start; + + /* + * Move the changed region back, so long as the + * previous unchanged line matches the last changed one. + * This merges with previous changed regions. + */ + while ($start > 0 && $lines[$start - 1] == $lines[$i - 1]) { + $changed[--$start] = 1; + $changed[--$i] = FALSE; + while ($start > 0 && $changed[$start - 1]) { + $start--; + } + USE_ASSERTS && assert('$j > 0'); + while ($other_changed[--$j]) { + continue; + } + USE_ASSERTS && assert('$j >= 0 && !$other_changed[$j]'); + } + + /* + * Set CORRESPONDING to the end of the changed run, at the last + * point where it corresponds to a changed run in the other file. + * CORRESPONDING == LEN means no such point has been found. + */ + $corresponding = $j < $other_len ? $i : $len; + + /* + * Move the changed region forward, so long as the + * first changed line matches the following unchanged one. + * This merges with following changed regions. + * Do this second, so that if there are no merges, + * the changed region is moved forward as far as possible. + */ + while ($i < $len && $lines[$start] == $lines[$i]) { + $changed[$start++] = FALSE; + $changed[$i++] = 1; + while ($i < $len && $changed[$i]) { + $i++; + } + USE_ASSERTS && assert('$j < $other_len && ! $other_changed[$j]'); + $j++; + if ($j < $other_len && $other_changed[$j]) { + $corresponding = $i; + while ($j < $other_len && $other_changed[$j]) { + $j++; + } + } + } + } while ($runlength != $i - $start); + + /* + * If possible, move the fully-merged run of changes + * back to a corresponding run in the other file. + */ + while ($corresponding < $i) { + $changed[--$start] = 1; + $changed[--$i] = 0; + USE_ASSERTS && assert('$j > 0'); + while ($other_changed[--$j]) { + continue; + } + USE_ASSERTS && assert('$j >= 0 && !$other_changed[$j]'); + } + } + } +} + +/** + * Class representing a 'diff' between two sequences of strings. + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class Diff { + var $edits; + + /** + * Constructor. + * Computes diff between sequences of strings. + * + * @param $from_lines array An array of strings. + * (Typically these are lines from a file.) + * @param $to_lines array An array of strings. + */ + function Diff($from_lines, $to_lines) { + $eng = new _DiffEngine; + $this->edits = $eng->diff($from_lines, $to_lines); + //$this->_check($from_lines, $to_lines); + } + + /** + * Compute reversed Diff. + * + * SYNOPSIS: + * + * $diff = new Diff($lines1, $lines2); + * $rev = $diff->reverse(); + * @return object A Diff object representing the inverse of the + * original diff. + */ + function reverse() { + $rev = $this; + $rev->edits = array(); + foreach ($this->edits as $edit) { + $rev->edits[] = $edit->reverse(); + } + return $rev; + } + + /** + * Check for empty diff. + * + * @return bool True iff two sequences were identical. + */ + function isEmpty() { + foreach ($this->edits as $edit) { + if ($edit->type != 'copy') { + return FALSE; + } + } + return TRUE; + } + + /** + * Compute the length of the Longest Common Subsequence (LCS). + * + * This is mostly for diagnostic purposed. + * + * @return int The length of the LCS. + */ + function lcs() { + $lcs = 0; + foreach ($this->edits as $edit) { + if ($edit->type == 'copy') { + $lcs += sizeof($edit->orig); + } + } + return $lcs; + } + + /** + * Get the original set of lines. + * + * This reconstructs the $from_lines parameter passed to the + * constructor. + * + * @return array The original sequence of strings. + */ + function orig() { + $lines = array(); + + foreach ($this->edits as $edit) { + if ($edit->orig) { + array_splice($lines, sizeof($lines), 0, $edit->orig); + } + } + return $lines; + } + + /** + * Get the closing set of lines. + * + * This reconstructs the $to_lines parameter passed to the + * constructor. + * + * @return array The sequence of strings. + */ + function closing() { + $lines = array(); + + foreach ($this->edits as $edit) { + if ($edit->closing) { + array_splice($lines, sizeof($lines), 0, $edit->closing); + } + } + return $lines; + } + + /** + * Check a Diff for validity. + * + * This is here only for debugging purposes. + */ + function _check($from_lines, $to_lines) { + if (serialize($from_lines) != serialize($this->orig())) { + trigger_error("Reconstructed original doesn't match", E_USER_ERROR); + } + if (serialize($to_lines) != serialize($this->closing())) { + trigger_error("Reconstructed closing doesn't match", E_USER_ERROR); + } + + $rev = $this->reverse(); + if (serialize($to_lines) != serialize($rev->orig())) { + trigger_error("Reversed original doesn't match", E_USER_ERROR); + } + if (serialize($from_lines) != serialize($rev->closing())) { + trigger_error("Reversed closing doesn't match", E_USER_ERROR); + } + + + $prevtype = 'none'; + foreach ($this->edits as $edit) { + if ( $prevtype == $edit->type ) { + trigger_error("Edit sequence is non-optimal", E_USER_ERROR); + } + $prevtype = $edit->type; + } + + $lcs = $this->lcs(); + trigger_error('Diff okay: LCS = ' . $lcs, E_USER_NOTICE); + } +} + +/** + * FIXME: bad name. + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class MappedDiff extends Diff { + /** + * Constructor. + * + * Computes diff between sequences of strings. + * + * This can be used to compute things like + * case-insensitve diffs, or diffs which ignore + * changes in white-space. + * + * @param $from_lines array An array of strings. + * (Typically these are lines from a file.) + * + * @param $to_lines array An array of strings. + * + * @param $mapped_from_lines array This array should + * have the same size number of elements as $from_lines. + * The elements in $mapped_from_lines and + * $mapped_to_lines are what is actually compared + * when computing the diff. + * + * @param $mapped_to_lines array This array should + * have the same number of elements as $to_lines. + */ + function MappedDiff($from_lines, $to_lines, $mapped_from_lines, $mapped_to_lines) { + + assert(sizeof($from_lines) == sizeof($mapped_from_lines)); + assert(sizeof($to_lines) == sizeof($mapped_to_lines)); + + $this->Diff($mapped_from_lines, $mapped_to_lines); + + $xi = $yi = 0; + for ($i = 0; $i < sizeof($this->edits); $i++) { + $orig = &$this->edits[$i]->orig; + if (is_array($orig)) { + $orig = array_slice($from_lines, $xi, sizeof($orig)); + $xi += sizeof($orig); + } + + $closing = &$this->edits[$i]->closing; + if (is_array($closing)) { + $closing = array_slice($to_lines, $yi, sizeof($closing)); + $yi += sizeof($closing); + } + } + } +} + +/** + * A class to format Diffs + * + * This class formats the diff in classic diff format. + * It is intended that this class be customized via inheritance, + * to obtain fancier outputs. + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class DiffFormatter { + /** + * Should a block header be shown? + */ + var $show_header = TRUE; + + /** + * Number of leading context "lines" to preserve. + * + * This should be left at zero for this class, but subclasses + * may want to set this to other values. + */ + var $leading_context_lines = 0; + + /** + * Number of trailing context "lines" to preserve. + * + * This should be left at zero for this class, but subclasses + * may want to set this to other values. + */ + var $trailing_context_lines = 0; + + /** + * Format a diff. + * + * @param $diff object A Diff object. + * @return string The formatted output. + */ + function format($diff) { + $xi = $yi = 1; + $block = FALSE; + $context = array(); + + $nlead = $this->leading_context_lines; + $ntrail = $this->trailing_context_lines; + + $this->_start_diff(); + + foreach ($diff->edits as $edit) { + if ($edit->type == 'copy') { + if (is_array($block)) { + if (sizeof($edit->orig) <= $nlead + $ntrail) { + $block[] = $edit; + } + else { + if ($ntrail) { + $context = array_slice($edit->orig, 0, $ntrail); + $block[] = new _DiffOp_Copy($context); + } + $this->_block($x0, $ntrail + $xi - $x0, $y0, $ntrail + $yi - $y0, $block); + $block = FALSE; + } + } + $context = $edit->orig; + } + else { + if (! is_array($block)) { + $context = array_slice($context, sizeof($context) - $nlead); + $x0 = $xi - sizeof($context); + $y0 = $yi - sizeof($context); + $block = array(); + if ($context) { + $block[] = new _DiffOp_Copy($context); + } + } + $block[] = $edit; + } + + if ($edit->orig) { + $xi += sizeof($edit->orig); + } + if ($edit->closing) { + $yi += sizeof($edit->closing); + } + } + + if (is_array($block)) { + $this->_block($x0, $xi - $x0, $y0, $yi - $y0, $block); + } + $end = $this->_end_diff(); + + if (!empty($xi)) { + $this->line_stats['counter']['x'] += $xi; + } + if (!empty($yi)) { + $this->line_stats['counter']['y'] += $yi; + } + + return $end; + } + + function _block($xbeg, $xlen, $ybeg, $ylen, &$edits) { + $this->_start_block($this->_block_header($xbeg, $xlen, $ybeg, $ylen)); + foreach ($edits as $edit) { + if ($edit->type == 'copy') { + $this->_context($edit->orig); + } + elseif ($edit->type == 'add') { + $this->_added($edit->closing); + } + elseif ($edit->type == 'delete') { + $this->_deleted($edit->orig); + } + elseif ($edit->type == 'change') { + $this->_changed($edit->orig, $edit->closing); + } + else { + trigger_error('Unknown edit type', E_USER_ERROR); + } + } + $this->_end_block(); + } + + function _start_diff() { + ob_start(); + } + + function _end_diff() { + $val = ob_get_contents(); + ob_end_clean(); + return $val; + } + + function _block_header($xbeg, $xlen, $ybeg, $ylen) { + if ($xlen > 1) { + $xbeg .= "," . ($xbeg + $xlen - 1); + } + if ($ylen > 1) { + $ybeg .= "," . ($ybeg + $ylen - 1); + } + + return $xbeg . ($xlen ? ($ylen ? 'c' : 'd') : 'a') . $ybeg; + } + + function _start_block($header) { + if ($this->show_header) { + echo $header . "\n"; + } + } + + function _end_block() { + } + + function _lines($lines, $prefix = ' ') { + foreach ($lines as $line) { + echo "$prefix $line\n"; + } + } + + function _context($lines) { + $this->_lines($lines); + } + + function _added($lines) { + $this->_lines($lines, '>'); + } + function _deleted($lines) { + $this->_lines($lines, '<'); + } + + function _changed($orig, $closing) { + $this->_deleted($orig); + echo "---\n"; + $this->_added($closing); + } +} + + +/** + * Additions by Axel Boldt follow, partly taken from diff.php, phpwiki-1.3.3 + * + */ + +define('NBSP', ' '); // iso-8859-x non-breaking space. + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _HWLDF_WordAccumulator { + function _HWLDF_WordAccumulator() { + $this->_lines = array(); + $this->_line = ''; + $this->_group = ''; + $this->_tag = ''; + } + + function _flushGroup($new_tag) { + if ($this->_group !== '') { + if ($this->_tag == 'mark') { + $this->_line .= '' . check_plain($this->_group) . ''; + } + else { + $this->_line .= check_plain($this->_group); + } + } + $this->_group = ''; + $this->_tag = $new_tag; + } + + function _flushLine($new_tag) { + $this->_flushGroup($new_tag); + if ($this->_line != '') { + array_push($this->_lines, $this->_line); + } + else { + // make empty lines visible by inserting an NBSP + array_push($this->_lines, NBSP); + } + $this->_line = ''; + } + + function addWords($words, $tag = '') { + if ($tag != $this->_tag) { + $this->_flushGroup($tag); + } + foreach ($words as $word) { + // new-line should only come as first char of word. + if ($word == '') { + continue; + } + if ($word[0] == "\n") { + $this->_flushLine($tag); + $word = drupal_substr($word, 1); + } + assert(!strstr($word, "\n")); + $this->_group .= $word; + } + } + + function getLines() { + $this->_flushLine('~done'); + return $this->_lines; + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class WordLevelDiff extends MappedDiff { + function MAX_LINE_LENGTH() { + return 10000; + } + + function WordLevelDiff($orig_lines, $closing_lines) { + list($orig_words, $orig_stripped) = $this->_split($orig_lines); + list($closing_words, $closing_stripped) = $this->_split($closing_lines); + + $this->MappedDiff($orig_words, $closing_words, $orig_stripped, $closing_stripped); + } + + function _split($lines) { + $words = array(); + $stripped = array(); + $first = TRUE; + foreach ($lines as $line) { + // If the line is too long, just pretend the entire line is one big word + // This prevents resource exhaustion problems + if ( $first ) { + $first = FALSE; + } + else { + $words[] = "\n"; + $stripped[] = "\n"; + } + if ( drupal_strlen( $line ) > $this->MAX_LINE_LENGTH() ) { + $words[] = $line; + $stripped[] = $line; + } + else { + if (preg_match_all('/ ( [^\S\n]+ | [0-9_A-Za-z\x80-\xff]+ | . ) (?: (?!< \n) [^\S\n])? /xs', $line, $m)) { + $words = array_merge($words, $m[0]); + $stripped = array_merge($stripped, $m[1]); + } + } + } + return array($words, $stripped); + } + + function orig() { + $orig = new _HWLDF_WordAccumulator; + + foreach ($this->edits as $edit) { + if ($edit->type == 'copy') { + $orig->addWords($edit->orig); + } + elseif ($edit->orig) { + $orig->addWords($edit->orig, 'mark'); + } + } + $lines = $orig->getLines(); + return $lines; + } + + function closing() { + $closing = new _HWLDF_WordAccumulator; + + foreach ($this->edits as $edit) { + if ($edit->type == 'copy') { + $closing->addWords($edit->closing); + } + elseif ($edit->closing) { + $closing->addWords($edit->closing, 'mark'); + } + } + $lines = $closing->getLines(); + return $lines; + } +} + +/** + * Diff formatter which uses Drupal theme functions. + * @private + * @subpackage DifferenceEngine + */ +class DrupalDiffFormatter extends DiffFormatter { + + var $rows; + var $line_stats = array( + 'counter' => array('x' => 0, 'y' => 0), + 'offset' => array('x' => 0, 'y' => 0), + ); + + function DrupalDiffFormatter() { + $this->leading_context_lines = \Drupal::config('diff.settings')->get('diff_context_lines_leading'); + $this->trailing_context_lines = \Drupal::config('diff.settings')->get('diff_context_lines_trailing'); + } + + function _start_diff() { + $this->rows = array(); + } + + function _end_diff() { + return $this->rows; + } + + function _block_header($xbeg, $xlen, $ybeg, $ylen) { + return array( + array( + 'data' => _theme('diff_header_line', array('lineno' => $xbeg + $this->line_stats['offset']['x'])), + 'colspan' => 2, + ), + array( + 'data' => _theme('diff_header_line', array('lineno' => $ybeg + $this->line_stats['offset']['y'])), + 'colspan' => 2, + ) + ); + } + + function _start_block($header) { + if ($this->show_header) { + $this->rows[] = $header; + } + } + + function _end_block() { + } + + function _lines($lines, $prefix=' ', $color='white') { + } + + /** + * Note: you should HTML-escape parameter before calling this. + */ + function addedLine($line) { + return array( + array( + 'data' => '+', + 'class' => 'diff-marker', + ), + array( + 'data' => _theme('diff_content_line', array('line' => $line)), + 'class' => 'diff-context diff-addedline', + ) + ); + } + + /** + * Note: you should HTML-escape parameter before calling this. + */ + function deletedLine($line) { + return array( + array( + 'data' => '-', + 'class' => 'diff-marker', + ), + array( + 'data' => _theme('diff_content_line', array('line' => $line)), + 'class' => 'diff-context diff-deletedline', + ) + ); + } + + /** + * Note: you should HTML-escape parameter before calling this. + */ + function contextLine($line) { + return array( + ' ', + array( + 'data' => _theme('diff_content_line', array('line' => $line)), + 'class' => 'diff-context', + ) + ); + } + + function emptyLine() { + return array( + ' ', + _theme('diff_empty_line', array('line' => ' ')), + ); + } + + function _added($lines) { + foreach ($lines as $line) { + $this->rows[] = array_merge($this->emptyLine(), $this->addedLine(check_plain($line))); + } + } + + function _deleted($lines) { + foreach ($lines as $line) { + $this->rows[] = array_merge($this->deletedLine(check_plain($line)), $this->emptyLine()); + } + } + + function _context($lines) { + foreach ($lines as $line) { + $this->rows[] = array_merge($this->contextLine(check_plain($line)), $this->contextLine(check_plain($line))); + } + } + + function _changed($orig, $closing) { + $diff = new WordLevelDiff($orig, $closing); + $del = $diff->orig(); + $add = $diff->closing(); + + // Notice that WordLevelDiff returns HTML-escaped output. + // Hence, we will be calling addedLine/deletedLine without HTML-escaping. + + while ($line = array_shift($del)) { + $aline = array_shift( $add ); + $this->rows[] = array_merge($this->deletedLine($line), isset($aline) ? $this->addedLine($aline) : $this->emptyLine()); + } + foreach ($add as $line) { // If any leftovers + $this->rows[] = array_merge($this->emptyLine(), $this->addedLine($line)); + } + } +} + +/** + * Drupal inline Diff formatter. + * @private + * @subpackage DifferenceEngine + */ +class DrupalDiffInline { + var $a; + var $b; + + /** + * Constructor. + */ + function __construct($a, $b) { + $this->a = $a; + $this->b = $b; + } + + /** + * Render differences inline using HTML markup. + */ + function render() { + $a = preg_split('/(<[^>]+?>| )/', $this->a, -1, PREG_SPLIT_DELIM_CAPTURE); + $b = preg_split('/(<[^>]+?>| )/', $this->b, -1, PREG_SPLIT_DELIM_CAPTURE); + $diff = new Diff($a, $b); + $diff->edits = $this->process_edits($diff->edits); + + // Assemble highlighted output + $output = ''; + foreach ($diff->edits as $chunk) { + switch ($chunk->type) { + case 'copy': + $output .= implode('', $chunk->closing); + break; + case 'delete': + foreach ($chunk->orig as $i => $piece) { + if (strpos($piece, '<') === 0 && drupal_substr($piece, drupal_strlen($piece) - 1) === '>') { + $output .= $piece; + } + else { + $output .= _theme('diff_inline_chunk', array('text' => $piece, 'type' => $chunk->type)); + } + } + break; + default: + $chunk->closing = $this->process_chunk($chunk->closing); + foreach ($chunk->closing as $i => $piece) { + if ($piece === ' ' || (strpos($piece, '<') === 0 && drupal_substr($piece, drupal_strlen($piece) - 1) === '>' && drupal_strtolower(drupal_substr($piece, 1, 3)) != 'img')) { + $output .= $piece; + } + else { + $output .= _theme('diff_inline_chunk', array('text' => $piece, 'type' => $chunk->type)); + } + } + break; + } + } + return $output; + } + + /** + * Merge chunk segments between tag delimiters. + */ + function process_chunk($chunk) { + $processed = array(); + $j = 0; + foreach ($chunk as $i => $piece) { + $next = isset($chunk[$i+1]) ? $chunk[$i+1] : NULL; + if (!isset($processed[$j])) { + $processed[$j] = ''; + } + if (strpos($piece, '<') === 0 && drupal_substr($piece, drupal_strlen($piece) - 1) === '>') { + $processed[$j] = $piece; + $j++; + } + elseif (isset($next) && strpos($next, '<') === 0 && drupal_substr($next, drupal_strlen($next) - 1) === '>') { + $processed[$j] .= $piece; + $j++; + } + else { + $processed[$j] .= $piece; + } + } + return $processed; + } + + /** + * Merge copy and equivalent edits into intelligible chunks. + */ + function process_edits($edits) { + $processed = array(); + $current = array_shift($edits); + + // Make two passes -- first merge space delimiter copies back into their originals. + while ($chunk = array_shift($edits)) { + if ($chunk->type == 'copy' && $chunk->orig === array(' ')) { + $current->orig = array_merge((array) $current->orig, (array) $chunk->orig); + $current->closing = array_merge((array) $current->closing, (array) $chunk->closing); + } + else { + $processed[] = $current; + $current = $chunk; + } + } + $processed[] = $current; + + // Initial setup + $edits = $processed; + $processed = array(); + $current = array_shift($edits); + + // Second, merge equivalent chunks into each other. + while ($chunk = array_shift($edits)) { + if ($current->type == $chunk->type) { + $current->orig = array_merge((array) $current->orig, (array) $chunk->orig); + $current->closing = array_merge((array) $current->closing, (array) $chunk->closing); + } + else { + $processed[] = $current; + $current = $chunk; + } + } + $processed[] = $current; + + return $processed; + } +} diff --git a/src/Form/DiffAdminGlobalEntitySettings.php b/src/Form/DiffAdminGlobalEntitySettings.php new file mode 100644 index 0000000..d8ea8d0 --- /dev/null +++ b/src/Form/DiffAdminGlobalEntitySettings.php @@ -0,0 +1,92 @@ +config('diff.settings'); + + foreach (Element::children($form) as $variable) { + $config->set($variable, $form_state->getValue($form[$variable]['#parents'])); + } + $config->save(); + + if (method_exists($this, '_submitForm')) { + $this->_submitForm($form, $form_state); + } + + parent::submitForm($form, $form_state); + } + +/** + * Global entity settings. + */ +function buildForm(array $form, FormStateInterface $form_state, $entity_type = NULL) { + $entity_info = \Drupal::entityManager()->getDefinition($entity_type); + drupal_set_title(t('Diff settings for %entity_label entities', array('%entity_label' => $entity_info['label'])), PASS_THROUGH); + + if ($options = module_invoke_all('entity_diff_options', $entity_type)) { + $form['diff_additional_options_' . $entity_type] = array( + '#type' => 'checkboxes', + '#title' => t('Property options'), + '#default_value' => \Drupal::config('diff.settings')->get('diff_additional_options_' . $entity_type), + '#options' => $options, + ); + } + else { + $form['diff_additional_options_' . $entity_type] = array( + '#type' => 'value', + '#value' => array(), + ); + } + + $form['diff_show_header_' . $entity_type] = array( + '#type' => 'checkbox', + '#title' => t('Show entity label row header'), + '#default_value' => \Drupal::config('diff.settings')->get('diff_show_header_' . $entity_type), + ); + if (\Drupal::currentUser()->hasPermission('administer permissions')) { + $admin_link = l(t('View the administration theme'), 'admin/people/permissions', array('fragment' => 'edit-view-the-administration-theme')); + } + else { + $admin_link = t('View the administration theme'); + } + $form['diff_admin_path_' . $entity_type] = array( + '#type' => 'checkbox', + '#title' => t('Use administration theme'), + '#description' => t('This option will enable users with the !link permission to use the admin theme when doing comparisons.', array('!link' => $admin_link)), + '#default_value' => \Drupal::config('diff.settings')->get('diff_admin_path_' . $entity_type), + ); + $form['diff_default_state_' . $entity_type] = array( + '#type' => 'select', + '#title' => t('Diff default state'), + '#default_value' => \Drupal::config('diff.settings')->get('diff_default_state_' . $entity_type), + '#options' => array( + 'raw' => t('HTML view'), + 'raw_plain' => t('Plain view'), + ), + '#empty_option' => t('- None -'), + '#description' => t('Default display to show when viewing a diff, html tags in diffed result or as plain text.'), + ); + return parent::buildForm($form, $form_state); +} + +} diff --git a/src/Form/DiffAdminGlobalFieldSettings.php b/src/Form/DiffAdminGlobalFieldSettings.php new file mode 100644 index 0000000..291f798 --- /dev/null +++ b/src/Form/DiffAdminGlobalFieldSettings.php @@ -0,0 +1,70 @@ +config('diff.settings'); + + foreach (Element::children($form) as $variable) { + $config->set($variable, $form_state->getValue($form[$variable]['#parents'])); + } + $config->save(); + + if (method_exists($this, '_submitForm')) { + $this->_submitForm($form, $form_state); + } + + parent::submitForm($form, $form_state); + } + +/** + * Menu form callback for the field settings. + */ +function buildForm(array $form, FormStateInterface $form_state, $type = NULL) { + module_load_include('diff.inc', 'diff'); + + $field_types = \Drupal::service('plugin.manager.field.field_type')->getDefinitions(); + if (!isset($field_types[$type])) { + drupal_set_message(t('Invalid field type.'), 'error'); + drupal_goto('admin/config/content/diff/fields'); + } + $field_type = $field_types[$type]; + + // Set the title to give more context to this page. + drupal_set_title(t('Global settings for %label fields', array( + '%label' => $field_type['label'], + )), PASS_THROUGH); + + $variable_name = "diff_{$field_type['module']}_field_{$type}_default_options"; + $settings = \Drupal::config('diff.settings')->get($variable_name); + $settings = _diff_field_default_settings($field_type['module'], $type, $settings); + $func = $field_type['module'] . '_field_diff_options_form'; + if (function_exists($func) && ($options_form = $func($type, $settings))) { + $form[$variable_name] = $options_form; + } + $form[$variable_name]['#tree'] = TRUE; + + diff_global_settings_form($form[$variable_name], $form_state, $type, $settings); + return parent::buildForm($form, $form_state); +} + +} diff --git a/src/Form/DiffAdminSettings.php b/src/Form/DiffAdminSettings.php new file mode 100644 index 0000000..7052c9d --- /dev/null +++ b/src/Form/DiffAdminSettings.php @@ -0,0 +1,85 @@ +config('diff.settings'); + + foreach (Element::children($form) as $variable) { + $config->set($variable, $form_state->getValue($form[$variable]['#parents'])); + } + $config->save(); + + if (method_exists($this, '_submitForm')) { + $this->_submitForm($form, $form_state); + } + + parent::submitForm($form, $form_state); + } + +/** + * General configuration form for controlling the diff behaviour. + */ +function buildForm(array $form, FormStateInterface $form_state) { + $form['diff_theme'] = array( + '#type' => 'select', + '#title' => t('CSS options'), + '#default_value' => \Drupal::config('diff.settings')->get('diff_theme'), + '#options' => array( + 'default' => t('Classic'), + 'boxes' => t('Boxes'), + ), + '#empty_option' => t('- None -'), + '#description' => t('Alter the CSS used when displaying diff results.'), + ); + $form['diff_radio_behavior'] = array( + '#type' => 'select', + '#title' => t('Diff radio behavior'), + '#default_value' => \Drupal::config('diff.settings')->get('diff_radio_behavior'), + '#options' => array( + 'simple' => t('Simple exclusion'), + 'linear' => t('Linear restrictions'), + ), + '#empty_option' => t('- None -'), + '#description' => t('Simple exclusion means that users will not be able to select the same revision, Linear restrictions means that users can only select older or newer revisions of the current selections.'), + ); + + $options = array_combine(array(0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10), array(0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10)); + $form['diff_context_lines_leading'] = array( + '#type' => 'select', + '#title' => t('Leading context lines'), + '#description' => t('This governs the number of unchanged leading context "lines" to preserve.'), + '#default_value' => \Drupal::config('diff.settings')->get('diff_context_lines_leading'), + '#options' => $options, + ); + $form['diff_context_lines_trailing'] = array( + '#type' => 'select', + '#title' => t('Trailing context lines'), + '#description' => t('This governs the number of unchanged trailing context "lines" to preserve.'), + '#default_value' => \Drupal::config('diff.settings')->get('diff_context_lines_trailing'), + '#options' => $options, + ); + + return parent::buildForm($form, $form_state); +} + +} diff --git a/src/MappedDiff.php b/src/MappedDiff.php new file mode 100644 index 0000000..f0c0d51 --- /dev/null +++ b/src/MappedDiff.php @@ -0,0 +1,1355 @@ + + * You may copy this code freely under the conditions of the GPL. + */ + +define('USE_ASSERTS', FALSE); + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp { + var $type; + var $orig; + var $closing; + + function reverse() { + trigger_error('pure virtual', E_USER_ERROR); + } + + function norig() { + return $this->orig ? sizeof($this->orig) : 0; + } + + function nclosing() { + return $this->closing ? sizeof($this->closing) : 0; + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Copy extends _DiffOp { + var $type = 'copy'; + + function _DiffOp_Copy($orig, $closing = FALSE) { + if (!is_array($closing)) { + $closing = $orig; + } + $this->orig = $orig; + $this->closing = $closing; + } + + function reverse() { + return new _DiffOp_Copy($this->closing, $this->orig); + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Delete extends _DiffOp { + var $type = 'delete'; + + function _DiffOp_Delete($lines) { + $this->orig = $lines; + $this->closing = FALSE; + } + + function reverse() { + return new _DiffOp_Add($this->orig); + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Add extends _DiffOp { + var $type = 'add'; + + function _DiffOp_Add($lines) { + $this->closing = $lines; + $this->orig = FALSE; + } + + function reverse() { + return new _DiffOp_Delete($this->closing); + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Change extends _DiffOp { + var $type = 'change'; + + function _DiffOp_Change($orig, $closing) { + $this->orig = $orig; + $this->closing = $closing; + } + + function reverse() { + return new _DiffOp_Change($this->closing, $this->orig); + } +} + + +/** + * Class used internally by Diff to actually compute the diffs. + * + * The algorithm used here is mostly lifted from the perl module + * Algorithm::Diff (version 1.06) by Ned Konz, which is available at: + * http://www.perl.com/CPAN/authors/id/N/NE/NEDKONZ/Algorithm-Diff-1.06.zip + * + * More ideas are taken from: + * http://www.ics.uci.edu/~eppstein/161/960229.html + * + * Some ideas are (and a bit of code) are from from analyze.c, from GNU + * diffutils-2.7, which can be found at: + * ftp://gnudist.gnu.org/pub/gnu/diffutils/diffutils-2.7.tar.gz + * + * closingly, some ideas (subdivision by NCHUNKS > 2, and some optimizations) + * are my own. + * + * Line length limits for robustness added by Tim Starling, 2005-08-31 + * + * @author Geoffrey T. Dairiki, Tim Starling + * @private + * @subpackage DifferenceEngine + */ +class _DiffEngine { + function MAX_XREF_LENGTH() { + return 10000; + } + + function diff($from_lines, $to_lines) { + + $n_from = sizeof($from_lines); + $n_to = sizeof($to_lines); + + $this->xchanged = $this->ychanged = array(); + $this->xv = $this->yv = array(); + $this->xind = $this->yind = array(); + unset($this->seq); + unset($this->in_seq); + unset($this->lcs); + + // Skip leading common lines. + for ($skip = 0; $skip < $n_from && $skip < $n_to; $skip++) { + if ($from_lines[$skip] !== $to_lines[$skip]) { + break; + } + $this->xchanged[$skip] = $this->ychanged[$skip] = FALSE; + } + // Skip trailing common lines. + $xi = $n_from; + $yi = $n_to; + for ($endskip = 0; --$xi > $skip && --$yi > $skip; $endskip++) { + if ($from_lines[$xi] !== $to_lines[$yi]) { + break; + } + $this->xchanged[$xi] = $this->ychanged[$yi] = FALSE; + } + + // Ignore lines which do not exist in both files. + for ($xi = $skip; $xi < $n_from - $endskip; $xi++) { + $xhash[$this->_line_hash($from_lines[$xi])] = 1; + } + + for ($yi = $skip; $yi < $n_to - $endskip; $yi++) { + $line = $to_lines[$yi]; + if ($this->ychanged[$yi] = empty($xhash[$this->_line_hash($line)])) { + continue; + } + $yhash[$this->_line_hash($line)] = 1; + $this->yv[] = $line; + $this->yind[] = $yi; + } + for ($xi = $skip; $xi < $n_from - $endskip; $xi++) { + $line = $from_lines[$xi]; + if ($this->xchanged[$xi] = empty($yhash[$this->_line_hash($line)])) { + continue; + } + $this->xv[] = $line; + $this->xind[] = $xi; + } + + // Find the LCS. + $this->_compareseq(0, sizeof($this->xv), 0, sizeof($this->yv)); + + // Merge edits when possible + $this->_shift_boundaries($from_lines, $this->xchanged, $this->ychanged); + $this->_shift_boundaries($to_lines, $this->ychanged, $this->xchanged); + + // Compute the edit operations. + $edits = array(); + $xi = $yi = 0; + while ($xi < $n_from || $yi < $n_to) { + USE_ASSERTS && assert($yi < $n_to || $this->xchanged[$xi]); + USE_ASSERTS && assert($xi < $n_from || $this->ychanged[$yi]); + + // Skip matching "snake". + $copy = array(); + while ( $xi < $n_from && $yi < $n_to && !$this->xchanged[$xi] && !$this->ychanged[$yi]) { + $copy[] = $from_lines[$xi++]; + ++$yi; + } + if ($copy) { + $edits[] = new _DiffOp_Copy($copy); + } + // Find deletes & adds. + $delete = array(); + while ($xi < $n_from && $this->xchanged[$xi]) { + $_fl = $from_lines[$xi++]; + if (strlen($_fl)) { + $delete[] = $_fl; + } + } + $add = array(); + while ($yi < $n_to && $this->ychanged[$yi]) { + $_tl = $to_lines[$yi++]; + if (strlen($_tl)) { + $add[] = $_tl; + } + } + if ($delete && $add) { + $edits[] = new _DiffOp_Change($delete, $add); + } + elseif ($delete) { + $edits[] = new _DiffOp_Delete($delete); + } + elseif ($add) { + $edits[] = new _DiffOp_Add($add); + } + } + return $edits; + } + + /** + * Returns the whole line if it's small enough, or the MD5 hash otherwise. + */ + function _line_hash($line) { + if (drupal_strlen($line) > $this->MAX_XREF_LENGTH()) { + return md5($line); + } + else { + return $line; + } + } + + + /** + * Divide the Largest Common Subsequence (LCS) of the sequences + * [XOFF, XLIM) and [YOFF, YLIM) into NCHUNKS approximately equally + * sized segments. + * + * Returns (LCS, PTS). LCS is the length of the LCS. PTS is an + * array of NCHUNKS+1 (X, Y) indexes giving the diving points between + * sub sequences. The first sub-sequence is contained in [X0, X1), + * [Y0, Y1), the second in [X1, X2), [Y1, Y2) and so on. Note + * that (X0, Y0) == (XOFF, YOFF) and + * (X[NCHUNKS], Y[NCHUNKS]) == (XLIM, YLIM). + * + * This function assumes that the first lines of the specified portions + * of the two files do not match, and likewise that the last lines do not + * match. The caller must trim matching lines from the beginning and end + * of the portions it is going to specify. + */ + function _diag($xoff, $xlim, $yoff, $ylim, $nchunks) { + $flip = FALSE; + + if ($xlim - $xoff > $ylim - $yoff) { + // Things seems faster (I'm not sure I understand why) + // when the shortest sequence in X. + $flip = TRUE; + list($xoff, $xlim, $yoff, $ylim) = array($yoff, $ylim, $xoff, $xlim); + } + + if ($flip) { + for ($i = $ylim - 1; $i >= $yoff; $i--) { + $ymatches[$this->xv[$i]][] = $i; + } + } + else { + for ($i = $ylim - 1; $i >= $yoff; $i--) { + $ymatches[$this->yv[$i]][] = $i; + } + } + $this->lcs = 0; + $this->seq[0]= $yoff - 1; + $this->in_seq = array(); + $ymids[0] = array(); + + $numer = $xlim - $xoff + $nchunks - 1; + $x = $xoff; + for ($chunk = 0; $chunk < $nchunks; $chunk++) { + if ($chunk > 0) { + for ($i = 0; $i <= $this->lcs; $i++) { + $ymids[$i][$chunk-1] = $this->seq[$i]; + } + } + + $x1 = $xoff + (int)(($numer + ($xlim-$xoff)*$chunk) / $nchunks); + for ( ; $x < $x1; $x++) { + $line = $flip ? $this->yv[$x] : $this->xv[$x]; + if (empty($ymatches[$line])) { + continue; + } + $matches = $ymatches[$line]; + reset($matches); + while (list ($junk, $y) = each($matches)) { + if (empty($this->in_seq[$y])) { + $k = $this->_lcs_pos($y); + USE_ASSERTS && assert($k > 0); + $ymids[$k] = $ymids[$k-1]; + break; + } + } + while (list ($junk, $y) = each($matches)) { + if ($y > $this->seq[$k-1]) { + USE_ASSERTS && assert($y < $this->seq[$k]); + // Optimization: this is a common case: + // next match is just replacing previous match. + $this->in_seq[$this->seq[$k]] = FALSE; + $this->seq[$k] = $y; + $this->in_seq[$y] = 1; + } + elseif (empty($this->in_seq[$y])) { + $k = $this->_lcs_pos($y); + USE_ASSERTS && assert($k > 0); + $ymids[$k] = $ymids[$k-1]; + } + } + } + } + + $seps[] = $flip ? array($yoff, $xoff) : array($xoff, $yoff); + $ymid = $ymids[$this->lcs]; + for ($n = 0; $n < $nchunks - 1; $n++) { + $x1 = $xoff + (int)(($numer + ($xlim - $xoff) * $n) / $nchunks); + $y1 = $ymid[$n] + 1; + $seps[] = $flip ? array($y1, $x1) : array($x1, $y1); + } + $seps[] = $flip ? array($ylim, $xlim) : array($xlim, $ylim); + + return array($this->lcs, $seps); + } + + function _lcs_pos($ypos) { + + $end = $this->lcs; + if ($end == 0 || $ypos > $this->seq[$end]) { + $this->seq[++$this->lcs] = $ypos; + $this->in_seq[$ypos] = 1; + return $this->lcs; + } + + $beg = 1; + while ($beg < $end) { + $mid = (int)(($beg + $end) / 2); + if ($ypos > $this->seq[$mid]) { + $beg = $mid + 1; + } + else { + $end = $mid; + } + } + + USE_ASSERTS && assert($ypos != $this->seq[$end]); + + $this->in_seq[$this->seq[$end]] = FALSE; + $this->seq[$end] = $ypos; + $this->in_seq[$ypos] = 1; + return $end; + } + + /** + * Find LCS of two sequences. + * + * The results are recorded in the vectors $this->{x,y}changed[], by + * storing a 1 in the element for each line that is an insertion + * or deletion (ie. is not in the LCS). + * + * The subsequence of file 0 is [XOFF, XLIM) and likewise for file 1. + * + * Note that XLIM, YLIM are exclusive bounds. + * All line numbers are origin-0 and discarded lines are not counted. + */ + function _compareseq($xoff, $xlim, $yoff, $ylim) { + + // Slide down the bottom initial diagonal. + while ($xoff < $xlim && $yoff < $ylim && $this->xv[$xoff] == $this->yv[$yoff]) { + ++$xoff; + ++$yoff; + } + + // Slide up the top initial diagonal. + while ($xlim > $xoff && $ylim > $yoff && $this->xv[$xlim - 1] == $this->yv[$ylim - 1]) { + --$xlim; + --$ylim; + } + + if ($xoff == $xlim || $yoff == $ylim) { + $lcs = 0; + } + else { + // This is ad hoc but seems to work well. + //$nchunks = sqrt(min($xlim - $xoff, $ylim - $yoff) / 2.5); + //$nchunks = max(2, min(8, (int)$nchunks)); + $nchunks = min(7, $xlim - $xoff, $ylim - $yoff) + 1; + list($lcs, $seps) + = $this->_diag($xoff, $xlim, $yoff, $ylim, $nchunks); + } + + if ($lcs == 0) { + // X and Y sequences have no common subsequence: + // mark all changed. + while ($yoff < $ylim) { + $this->ychanged[$this->yind[$yoff++]] = 1; + } + while ($xoff < $xlim) { + $this->xchanged[$this->xind[$xoff++]] = 1; + } + } + else { + // Use the partitions to split this problem into subproblems. + reset($seps); + $pt1 = $seps[0]; + while ($pt2 = next($seps)) { + $this->_compareseq ($pt1[0], $pt2[0], $pt1[1], $pt2[1]); + $pt1 = $pt2; + } + } + } + + /** + * Adjust inserts/deletes of identical lines to join changes + * as much as possible. + * + * We do something when a run of changed lines include a + * line at one end and has an excluded, identical line at the other. + * We are free to choose which identical line is included. + * `compareseq' usually chooses the one at the beginning, + * but usually it is cleaner to consider the following identical line + * to be the "change". + * + * This is extracted verbatim from analyze.c (GNU diffutils-2.7). + */ + function _shift_boundaries($lines, &$changed, $other_changed) { + $i = 0; + $j = 0; + + USE_ASSERTS && assert('sizeof($lines) == sizeof($changed)'); + $len = sizeof($lines); + $other_len = sizeof($other_changed); + + while (1) { + /* + * Scan forwards to find beginning of another run of changes. + * Also keep track of the corresponding point in the other file. + * + * Throughout this code, $i and $j are adjusted together so that + * the first $i elements of $changed and the first $j elements + * of $other_changed both contain the same number of zeros + * (unchanged lines). + * Furthermore, $j is always kept so that $j == $other_len or + * $other_changed[$j] == FALSE. + */ + while ($j < $other_len && $other_changed[$j]) { + $j++; + } + while ($i < $len && ! $changed[$i]) { + USE_ASSERTS && assert('$j < $other_len && ! $other_changed[$j]'); + $i++; + $j++; + while ($j < $other_len && $other_changed[$j]) { + $j++; + } + } + + if ($i == $len) { + break; + } + $start = $i; + + // Find the end of this run of changes. + while (++$i < $len && $changed[$i]) { + continue; + } + + do { + /* + * Record the length of this run of changes, so that + * we can later determine whether the run has grown. + */ + $runlength = $i - $start; + + /* + * Move the changed region back, so long as the + * previous unchanged line matches the last changed one. + * This merges with previous changed regions. + */ + while ($start > 0 && $lines[$start - 1] == $lines[$i - 1]) { + $changed[--$start] = 1; + $changed[--$i] = FALSE; + while ($start > 0 && $changed[$start - 1]) { + $start--; + } + USE_ASSERTS && assert('$j > 0'); + while ($other_changed[--$j]) { + continue; + } + USE_ASSERTS && assert('$j >= 0 && !$other_changed[$j]'); + } + + /* + * Set CORRESPONDING to the end of the changed run, at the last + * point where it corresponds to a changed run in the other file. + * CORRESPONDING == LEN means no such point has been found. + */ + $corresponding = $j < $other_len ? $i : $len; + + /* + * Move the changed region forward, so long as the + * first changed line matches the following unchanged one. + * This merges with following changed regions. + * Do this second, so that if there are no merges, + * the changed region is moved forward as far as possible. + */ + while ($i < $len && $lines[$start] == $lines[$i]) { + $changed[$start++] = FALSE; + $changed[$i++] = 1; + while ($i < $len && $changed[$i]) { + $i++; + } + USE_ASSERTS && assert('$j < $other_len && ! $other_changed[$j]'); + $j++; + if ($j < $other_len && $other_changed[$j]) { + $corresponding = $i; + while ($j < $other_len && $other_changed[$j]) { + $j++; + } + } + } + } while ($runlength != $i - $start); + + /* + * If possible, move the fully-merged run of changes + * back to a corresponding run in the other file. + */ + while ($corresponding < $i) { + $changed[--$start] = 1; + $changed[--$i] = 0; + USE_ASSERTS && assert('$j > 0'); + while ($other_changed[--$j]) { + continue; + } + USE_ASSERTS && assert('$j >= 0 && !$other_changed[$j]'); + } + } + } +} + +/** + * Class representing a 'diff' between two sequences of strings. + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class Diff { + var $edits; + + /** + * Constructor. + * Computes diff between sequences of strings. + * + * @param $from_lines array An array of strings. + * (Typically these are lines from a file.) + * @param $to_lines array An array of strings. + */ + function Diff($from_lines, $to_lines) { + $eng = new _DiffEngine; + $this->edits = $eng->diff($from_lines, $to_lines); + //$this->_check($from_lines, $to_lines); + } + + /** + * Compute reversed Diff. + * + * SYNOPSIS: + * + * $diff = new Diff($lines1, $lines2); + * $rev = $diff->reverse(); + * @return object A Diff object representing the inverse of the + * original diff. + */ + function reverse() { + $rev = $this; + $rev->edits = array(); + foreach ($this->edits as $edit) { + $rev->edits[] = $edit->reverse(); + } + return $rev; + } + + /** + * Check for empty diff. + * + * @return bool True iff two sequences were identical. + */ + function isEmpty() { + foreach ($this->edits as $edit) { + if ($edit->type != 'copy') { + return FALSE; + } + } + return TRUE; + } + + /** + * Compute the length of the Longest Common Subsequence (LCS). + * + * This is mostly for diagnostic purposed. + * + * @return int The length of the LCS. + */ + function lcs() { + $lcs = 0; + foreach ($this->edits as $edit) { + if ($edit->type == 'copy') { + $lcs += sizeof($edit->orig); + } + } + return $lcs; + } + + /** + * Get the original set of lines. + * + * This reconstructs the $from_lines parameter passed to the + * constructor. + * + * @return array The original sequence of strings. + */ + function orig() { + $lines = array(); + + foreach ($this->edits as $edit) { + if ($edit->orig) { + array_splice($lines, sizeof($lines), 0, $edit->orig); + } + } + return $lines; + } + + /** + * Get the closing set of lines. + * + * This reconstructs the $to_lines parameter passed to the + * constructor. + * + * @return array The sequence of strings. + */ + function closing() { + $lines = array(); + + foreach ($this->edits as $edit) { + if ($edit->closing) { + array_splice($lines, sizeof($lines), 0, $edit->closing); + } + } + return $lines; + } + + /** + * Check a Diff for validity. + * + * This is here only for debugging purposes. + */ + function _check($from_lines, $to_lines) { + if (serialize($from_lines) != serialize($this->orig())) { + trigger_error("Reconstructed original doesn't match", E_USER_ERROR); + } + if (serialize($to_lines) != serialize($this->closing())) { + trigger_error("Reconstructed closing doesn't match", E_USER_ERROR); + } + + $rev = $this->reverse(); + if (serialize($to_lines) != serialize($rev->orig())) { + trigger_error("Reversed original doesn't match", E_USER_ERROR); + } + if (serialize($from_lines) != serialize($rev->closing())) { + trigger_error("Reversed closing doesn't match", E_USER_ERROR); + } + + + $prevtype = 'none'; + foreach ($this->edits as $edit) { + if ( $prevtype == $edit->type ) { + trigger_error("Edit sequence is non-optimal", E_USER_ERROR); + } + $prevtype = $edit->type; + } + + $lcs = $this->lcs(); + trigger_error('Diff okay: LCS = ' . $lcs, E_USER_NOTICE); + } +} + +/** + * FIXME: bad name. + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class MappedDiff extends Diff { + /** + * Constructor. + * + * Computes diff between sequences of strings. + * + * This can be used to compute things like + * case-insensitve diffs, or diffs which ignore + * changes in white-space. + * + * @param $from_lines array An array of strings. + * (Typically these are lines from a file.) + * + * @param $to_lines array An array of strings. + * + * @param $mapped_from_lines array This array should + * have the same size number of elements as $from_lines. + * The elements in $mapped_from_lines and + * $mapped_to_lines are what is actually compared + * when computing the diff. + * + * @param $mapped_to_lines array This array should + * have the same number of elements as $to_lines. + */ + function MappedDiff($from_lines, $to_lines, $mapped_from_lines, $mapped_to_lines) { + + assert(sizeof($from_lines) == sizeof($mapped_from_lines)); + assert(sizeof($to_lines) == sizeof($mapped_to_lines)); + + $this->Diff($mapped_from_lines, $mapped_to_lines); + + $xi = $yi = 0; + for ($i = 0; $i < sizeof($this->edits); $i++) { + $orig = &$this->edits[$i]->orig; + if (is_array($orig)) { + $orig = array_slice($from_lines, $xi, sizeof($orig)); + $xi += sizeof($orig); + } + + $closing = &$this->edits[$i]->closing; + if (is_array($closing)) { + $closing = array_slice($to_lines, $yi, sizeof($closing)); + $yi += sizeof($closing); + } + } + } +} + +/** + * A class to format Diffs + * + * This class formats the diff in classic diff format. + * It is intended that this class be customized via inheritance, + * to obtain fancier outputs. + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class DiffFormatter { + /** + * Should a block header be shown? + */ + var $show_header = TRUE; + + /** + * Number of leading context "lines" to preserve. + * + * This should be left at zero for this class, but subclasses + * may want to set this to other values. + */ + var $leading_context_lines = 0; + + /** + * Number of trailing context "lines" to preserve. + * + * This should be left at zero for this class, but subclasses + * may want to set this to other values. + */ + var $trailing_context_lines = 0; + + /** + * Format a diff. + * + * @param $diff object A Diff object. + * @return string The formatted output. + */ + function format($diff) { + $xi = $yi = 1; + $block = FALSE; + $context = array(); + + $nlead = $this->leading_context_lines; + $ntrail = $this->trailing_context_lines; + + $this->_start_diff(); + + foreach ($diff->edits as $edit) { + if ($edit->type == 'copy') { + if (is_array($block)) { + if (sizeof($edit->orig) <= $nlead + $ntrail) { + $block[] = $edit; + } + else { + if ($ntrail) { + $context = array_slice($edit->orig, 0, $ntrail); + $block[] = new _DiffOp_Copy($context); + } + $this->_block($x0, $ntrail + $xi - $x0, $y0, $ntrail + $yi - $y0, $block); + $block = FALSE; + } + } + $context = $edit->orig; + } + else { + if (! is_array($block)) { + $context = array_slice($context, sizeof($context) - $nlead); + $x0 = $xi - sizeof($context); + $y0 = $yi - sizeof($context); + $block = array(); + if ($context) { + $block[] = new _DiffOp_Copy($context); + } + } + $block[] = $edit; + } + + if ($edit->orig) { + $xi += sizeof($edit->orig); + } + if ($edit->closing) { + $yi += sizeof($edit->closing); + } + } + + if (is_array($block)) { + $this->_block($x0, $xi - $x0, $y0, $yi - $y0, $block); + } + $end = $this->_end_diff(); + + if (!empty($xi)) { + $this->line_stats['counter']['x'] += $xi; + } + if (!empty($yi)) { + $this->line_stats['counter']['y'] += $yi; + } + + return $end; + } + + function _block($xbeg, $xlen, $ybeg, $ylen, &$edits) { + $this->_start_block($this->_block_header($xbeg, $xlen, $ybeg, $ylen)); + foreach ($edits as $edit) { + if ($edit->type == 'copy') { + $this->_context($edit->orig); + } + elseif ($edit->type == 'add') { + $this->_added($edit->closing); + } + elseif ($edit->type == 'delete') { + $this->_deleted($edit->orig); + } + elseif ($edit->type == 'change') { + $this->_changed($edit->orig, $edit->closing); + } + else { + trigger_error('Unknown edit type', E_USER_ERROR); + } + } + $this->_end_block(); + } + + function _start_diff() { + ob_start(); + } + + function _end_diff() { + $val = ob_get_contents(); + ob_end_clean(); + return $val; + } + + function _block_header($xbeg, $xlen, $ybeg, $ylen) { + if ($xlen > 1) { + $xbeg .= "," . ($xbeg + $xlen - 1); + } + if ($ylen > 1) { + $ybeg .= "," . ($ybeg + $ylen - 1); + } + + return $xbeg . ($xlen ? ($ylen ? 'c' : 'd') : 'a') . $ybeg; + } + + function _start_block($header) { + if ($this->show_header) { + echo $header . "\n"; + } + } + + function _end_block() { + } + + function _lines($lines, $prefix = ' ') { + foreach ($lines as $line) { + echo "$prefix $line\n"; + } + } + + function _context($lines) { + $this->_lines($lines); + } + + function _added($lines) { + $this->_lines($lines, '>'); + } + function _deleted($lines) { + $this->_lines($lines, '<'); + } + + function _changed($orig, $closing) { + $this->_deleted($orig); + echo "---\n"; + $this->_added($closing); + } +} + + +/** + * Additions by Axel Boldt follow, partly taken from diff.php, phpwiki-1.3.3 + * + */ + +define('NBSP', ' '); // iso-8859-x non-breaking space. + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _HWLDF_WordAccumulator { + function _HWLDF_WordAccumulator() { + $this->_lines = array(); + $this->_line = ''; + $this->_group = ''; + $this->_tag = ''; + } + + function _flushGroup($new_tag) { + if ($this->_group !== '') { + if ($this->_tag == 'mark') { + $this->_line .= '' . check_plain($this->_group) . ''; + } + else { + $this->_line .= check_plain($this->_group); + } + } + $this->_group = ''; + $this->_tag = $new_tag; + } + + function _flushLine($new_tag) { + $this->_flushGroup($new_tag); + if ($this->_line != '') { + array_push($this->_lines, $this->_line); + } + else { + // make empty lines visible by inserting an NBSP + array_push($this->_lines, NBSP); + } + $this->_line = ''; + } + + function addWords($words, $tag = '') { + if ($tag != $this->_tag) { + $this->_flushGroup($tag); + } + foreach ($words as $word) { + // new-line should only come as first char of word. + if ($word == '') { + continue; + } + if ($word[0] == "\n") { + $this->_flushLine($tag); + $word = drupal_substr($word, 1); + } + assert(!strstr($word, "\n")); + $this->_group .= $word; + } + } + + function getLines() { + $this->_flushLine('~done'); + return $this->_lines; + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class WordLevelDiff extends MappedDiff { + function MAX_LINE_LENGTH() { + return 10000; + } + + function WordLevelDiff($orig_lines, $closing_lines) { + list($orig_words, $orig_stripped) = $this->_split($orig_lines); + list($closing_words, $closing_stripped) = $this->_split($closing_lines); + + $this->MappedDiff($orig_words, $closing_words, $orig_stripped, $closing_stripped); + } + + function _split($lines) { + $words = array(); + $stripped = array(); + $first = TRUE; + foreach ($lines as $line) { + // If the line is too long, just pretend the entire line is one big word + // This prevents resource exhaustion problems + if ( $first ) { + $first = FALSE; + } + else { + $words[] = "\n"; + $stripped[] = "\n"; + } + if ( drupal_strlen( $line ) > $this->MAX_LINE_LENGTH() ) { + $words[] = $line; + $stripped[] = $line; + } + else { + if (preg_match_all('/ ( [^\S\n]+ | [0-9_A-Za-z\x80-\xff]+ | . ) (?: (?!< \n) [^\S\n])? /xs', $line, $m)) { + $words = array_merge($words, $m[0]); + $stripped = array_merge($stripped, $m[1]); + } + } + } + return array($words, $stripped); + } + + function orig() { + $orig = new _HWLDF_WordAccumulator; + + foreach ($this->edits as $edit) { + if ($edit->type == 'copy') { + $orig->addWords($edit->orig); + } + elseif ($edit->orig) { + $orig->addWords($edit->orig, 'mark'); + } + } + $lines = $orig->getLines(); + return $lines; + } + + function closing() { + $closing = new _HWLDF_WordAccumulator; + + foreach ($this->edits as $edit) { + if ($edit->type == 'copy') { + $closing->addWords($edit->closing); + } + elseif ($edit->closing) { + $closing->addWords($edit->closing, 'mark'); + } + } + $lines = $closing->getLines(); + return $lines; + } +} + +/** + * Diff formatter which uses Drupal theme functions. + * @private + * @subpackage DifferenceEngine + */ +class DrupalDiffFormatter extends DiffFormatter { + + var $rows; + var $line_stats = array( + 'counter' => array('x' => 0, 'y' => 0), + 'offset' => array('x' => 0, 'y' => 0), + ); + + function DrupalDiffFormatter() { + $this->leading_context_lines = \Drupal::config('diff.settings')->get('diff_context_lines_leading'); + $this->trailing_context_lines = \Drupal::config('diff.settings')->get('diff_context_lines_trailing'); + } + + function _start_diff() { + $this->rows = array(); + } + + function _end_diff() { + return $this->rows; + } + + function _block_header($xbeg, $xlen, $ybeg, $ylen) { + return array( + array( + 'data' => _theme('diff_header_line', array('lineno' => $xbeg + $this->line_stats['offset']['x'])), + 'colspan' => 2, + ), + array( + 'data' => _theme('diff_header_line', array('lineno' => $ybeg + $this->line_stats['offset']['y'])), + 'colspan' => 2, + ) + ); + } + + function _start_block($header) { + if ($this->show_header) { + $this->rows[] = $header; + } + } + + function _end_block() { + } + + function _lines($lines, $prefix=' ', $color='white') { + } + + /** + * Note: you should HTML-escape parameter before calling this. + */ + function addedLine($line) { + return array( + array( + 'data' => '+', + 'class' => 'diff-marker', + ), + array( + 'data' => _theme('diff_content_line', array('line' => $line)), + 'class' => 'diff-context diff-addedline', + ) + ); + } + + /** + * Note: you should HTML-escape parameter before calling this. + */ + function deletedLine($line) { + return array( + array( + 'data' => '-', + 'class' => 'diff-marker', + ), + array( + 'data' => _theme('diff_content_line', array('line' => $line)), + 'class' => 'diff-context diff-deletedline', + ) + ); + } + + /** + * Note: you should HTML-escape parameter before calling this. + */ + function contextLine($line) { + return array( + ' ', + array( + 'data' => _theme('diff_content_line', array('line' => $line)), + 'class' => 'diff-context', + ) + ); + } + + function emptyLine() { + return array( + ' ', + _theme('diff_empty_line', array('line' => ' ')), + ); + } + + function _added($lines) { + foreach ($lines as $line) { + $this->rows[] = array_merge($this->emptyLine(), $this->addedLine(check_plain($line))); + } + } + + function _deleted($lines) { + foreach ($lines as $line) { + $this->rows[] = array_merge($this->deletedLine(check_plain($line)), $this->emptyLine()); + } + } + + function _context($lines) { + foreach ($lines as $line) { + $this->rows[] = array_merge($this->contextLine(check_plain($line)), $this->contextLine(check_plain($line))); + } + } + + function _changed($orig, $closing) { + $diff = new WordLevelDiff($orig, $closing); + $del = $diff->orig(); + $add = $diff->closing(); + + // Notice that WordLevelDiff returns HTML-escaped output. + // Hence, we will be calling addedLine/deletedLine without HTML-escaping. + + while ($line = array_shift($del)) { + $aline = array_shift( $add ); + $this->rows[] = array_merge($this->deletedLine($line), isset($aline) ? $this->addedLine($aline) : $this->emptyLine()); + } + foreach ($add as $line) { // If any leftovers + $this->rows[] = array_merge($this->emptyLine(), $this->addedLine($line)); + } + } +} + +/** + * Drupal inline Diff formatter. + * @private + * @subpackage DifferenceEngine + */ +class DrupalDiffInline { + var $a; + var $b; + + /** + * Constructor. + */ + function __construct($a, $b) { + $this->a = $a; + $this->b = $b; + } + + /** + * Render differences inline using HTML markup. + */ + function render() { + $a = preg_split('/(<[^>]+?>| )/', $this->a, -1, PREG_SPLIT_DELIM_CAPTURE); + $b = preg_split('/(<[^>]+?>| )/', $this->b, -1, PREG_SPLIT_DELIM_CAPTURE); + $diff = new Diff($a, $b); + $diff->edits = $this->process_edits($diff->edits); + + // Assemble highlighted output + $output = ''; + foreach ($diff->edits as $chunk) { + switch ($chunk->type) { + case 'copy': + $output .= implode('', $chunk->closing); + break; + case 'delete': + foreach ($chunk->orig as $i => $piece) { + if (strpos($piece, '<') === 0 && drupal_substr($piece, drupal_strlen($piece) - 1) === '>') { + $output .= $piece; + } + else { + $output .= _theme('diff_inline_chunk', array('text' => $piece, 'type' => $chunk->type)); + } + } + break; + default: + $chunk->closing = $this->process_chunk($chunk->closing); + foreach ($chunk->closing as $i => $piece) { + if ($piece === ' ' || (strpos($piece, '<') === 0 && drupal_substr($piece, drupal_strlen($piece) - 1) === '>' && drupal_strtolower(drupal_substr($piece, 1, 3)) != 'img')) { + $output .= $piece; + } + else { + $output .= _theme('diff_inline_chunk', array('text' => $piece, 'type' => $chunk->type)); + } + } + break; + } + } + return $output; + } + + /** + * Merge chunk segments between tag delimiters. + */ + function process_chunk($chunk) { + $processed = array(); + $j = 0; + foreach ($chunk as $i => $piece) { + $next = isset($chunk[$i+1]) ? $chunk[$i+1] : NULL; + if (!isset($processed[$j])) { + $processed[$j] = ''; + } + if (strpos($piece, '<') === 0 && drupal_substr($piece, drupal_strlen($piece) - 1) === '>') { + $processed[$j] = $piece; + $j++; + } + elseif (isset($next) && strpos($next, '<') === 0 && drupal_substr($next, drupal_strlen($next) - 1) === '>') { + $processed[$j] .= $piece; + $j++; + } + else { + $processed[$j] .= $piece; + } + } + return $processed; + } + + /** + * Merge copy and equivalent edits into intelligible chunks. + */ + function process_edits($edits) { + $processed = array(); + $current = array_shift($edits); + + // Make two passes -- first merge space delimiter copies back into their originals. + while ($chunk = array_shift($edits)) { + if ($chunk->type == 'copy' && $chunk->orig === array(' ')) { + $current->orig = array_merge((array) $current->orig, (array) $chunk->orig); + $current->closing = array_merge((array) $current->closing, (array) $chunk->closing); + } + else { + $processed[] = $current; + $current = $chunk; + } + } + $processed[] = $current; + + // Initial setup + $edits = $processed; + $processed = array(); + $current = array_shift($edits); + + // Second, merge equivalent chunks into each other. + while ($chunk = array_shift($edits)) { + if ($current->type == $chunk->type) { + $current->orig = array_merge((array) $current->orig, (array) $chunk->orig); + $current->closing = array_merge((array) $current->closing, (array) $chunk->closing); + } + else { + $processed[] = $current; + $current = $chunk; + } + } + $processed[] = $current; + + return $processed; + } +} diff --git a/src/Plugin/Block/Inline.php b/src/Plugin/Block/Inline.php new file mode 100644 index 0000000..46398fd --- /dev/null +++ b/src/Plugin/Block/Inline.php @@ -0,0 +1,35 @@ + + * You may copy this code freely under the conditions of the GPL. + */ + +define('USE_ASSERTS', FALSE); + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp { + var $type; + var $orig; + var $closing; + + function reverse() { + trigger_error('pure virtual', E_USER_ERROR); + } + + function norig() { + return $this->orig ? sizeof($this->orig) : 0; + } + + function nclosing() { + return $this->closing ? sizeof($this->closing) : 0; + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Copy extends _DiffOp { + var $type = 'copy'; + + function _DiffOp_Copy($orig, $closing = FALSE) { + if (!is_array($closing)) { + $closing = $orig; + } + $this->orig = $orig; + $this->closing = $closing; + } + + function reverse() { + return new _DiffOp_Copy($this->closing, $this->orig); + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Delete extends _DiffOp { + var $type = 'delete'; + + function _DiffOp_Delete($lines) { + $this->orig = $lines; + $this->closing = FALSE; + } + + function reverse() { + return new _DiffOp_Add($this->orig); + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Add extends _DiffOp { + var $type = 'add'; + + function _DiffOp_Add($lines) { + $this->closing = $lines; + $this->orig = FALSE; + } + + function reverse() { + return new _DiffOp_Delete($this->closing); + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Change extends _DiffOp { + var $type = 'change'; + + function _DiffOp_Change($orig, $closing) { + $this->orig = $orig; + $this->closing = $closing; + } + + function reverse() { + return new _DiffOp_Change($this->closing, $this->orig); + } +} + + +/** + * Class used internally by Diff to actually compute the diffs. + * + * The algorithm used here is mostly lifted from the perl module + * Algorithm::Diff (version 1.06) by Ned Konz, which is available at: + * http://www.perl.com/CPAN/authors/id/N/NE/NEDKONZ/Algorithm-Diff-1.06.zip + * + * More ideas are taken from: + * http://www.ics.uci.edu/~eppstein/161/960229.html + * + * Some ideas are (and a bit of code) are from from analyze.c, from GNU + * diffutils-2.7, which can be found at: + * ftp://gnudist.gnu.org/pub/gnu/diffutils/diffutils-2.7.tar.gz + * + * closingly, some ideas (subdivision by NCHUNKS > 2, and some optimizations) + * are my own. + * + * Line length limits for robustness added by Tim Starling, 2005-08-31 + * + * @author Geoffrey T. Dairiki, Tim Starling + * @private + * @subpackage DifferenceEngine + */ +class _DiffEngine { + function MAX_XREF_LENGTH() { + return 10000; + } + + function diff($from_lines, $to_lines) { + + $n_from = sizeof($from_lines); + $n_to = sizeof($to_lines); + + $this->xchanged = $this->ychanged = array(); + $this->xv = $this->yv = array(); + $this->xind = $this->yind = array(); + unset($this->seq); + unset($this->in_seq); + unset($this->lcs); + + // Skip leading common lines. + for ($skip = 0; $skip < $n_from && $skip < $n_to; $skip++) { + if ($from_lines[$skip] !== $to_lines[$skip]) { + break; + } + $this->xchanged[$skip] = $this->ychanged[$skip] = FALSE; + } + // Skip trailing common lines. + $xi = $n_from; + $yi = $n_to; + for ($endskip = 0; --$xi > $skip && --$yi > $skip; $endskip++) { + if ($from_lines[$xi] !== $to_lines[$yi]) { + break; + } + $this->xchanged[$xi] = $this->ychanged[$yi] = FALSE; + } + + // Ignore lines which do not exist in both files. + for ($xi = $skip; $xi < $n_from - $endskip; $xi++) { + $xhash[$this->_line_hash($from_lines[$xi])] = 1; + } + + for ($yi = $skip; $yi < $n_to - $endskip; $yi++) { + $line = $to_lines[$yi]; + if ($this->ychanged[$yi] = empty($xhash[$this->_line_hash($line)])) { + continue; + } + $yhash[$this->_line_hash($line)] = 1; + $this->yv[] = $line; + $this->yind[] = $yi; + } + for ($xi = $skip; $xi < $n_from - $endskip; $xi++) { + $line = $from_lines[$xi]; + if ($this->xchanged[$xi] = empty($yhash[$this->_line_hash($line)])) { + continue; + } + $this->xv[] = $line; + $this->xind[] = $xi; + } + + // Find the LCS. + $this->_compareseq(0, sizeof($this->xv), 0, sizeof($this->yv)); + + // Merge edits when possible + $this->_shift_boundaries($from_lines, $this->xchanged, $this->ychanged); + $this->_shift_boundaries($to_lines, $this->ychanged, $this->xchanged); + + // Compute the edit operations. + $edits = array(); + $xi = $yi = 0; + while ($xi < $n_from || $yi < $n_to) { + USE_ASSERTS && assert($yi < $n_to || $this->xchanged[$xi]); + USE_ASSERTS && assert($xi < $n_from || $this->ychanged[$yi]); + + // Skip matching "snake". + $copy = array(); + while ( $xi < $n_from && $yi < $n_to && !$this->xchanged[$xi] && !$this->ychanged[$yi]) { + $copy[] = $from_lines[$xi++]; + ++$yi; + } + if ($copy) { + $edits[] = new _DiffOp_Copy($copy); + } + // Find deletes & adds. + $delete = array(); + while ($xi < $n_from && $this->xchanged[$xi]) { + $_fl = $from_lines[$xi++]; + if (strlen($_fl)) { + $delete[] = $_fl; + } + } + $add = array(); + while ($yi < $n_to && $this->ychanged[$yi]) { + $_tl = $to_lines[$yi++]; + if (strlen($_tl)) { + $add[] = $_tl; + } + } + if ($delete && $add) { + $edits[] = new _DiffOp_Change($delete, $add); + } + elseif ($delete) { + $edits[] = new _DiffOp_Delete($delete); + } + elseif ($add) { + $edits[] = new _DiffOp_Add($add); + } + } + return $edits; + } + + /** + * Returns the whole line if it's small enough, or the MD5 hash otherwise. + */ + function _line_hash($line) { + if (drupal_strlen($line) > $this->MAX_XREF_LENGTH()) { + return md5($line); + } + else { + return $line; + } + } + + + /** + * Divide the Largest Common Subsequence (LCS) of the sequences + * [XOFF, XLIM) and [YOFF, YLIM) into NCHUNKS approximately equally + * sized segments. + * + * Returns (LCS, PTS). LCS is the length of the LCS. PTS is an + * array of NCHUNKS+1 (X, Y) indexes giving the diving points between + * sub sequences. The first sub-sequence is contained in [X0, X1), + * [Y0, Y1), the second in [X1, X2), [Y1, Y2) and so on. Note + * that (X0, Y0) == (XOFF, YOFF) and + * (X[NCHUNKS], Y[NCHUNKS]) == (XLIM, YLIM). + * + * This function assumes that the first lines of the specified portions + * of the two files do not match, and likewise that the last lines do not + * match. The caller must trim matching lines from the beginning and end + * of the portions it is going to specify. + */ + function _diag($xoff, $xlim, $yoff, $ylim, $nchunks) { + $flip = FALSE; + + if ($xlim - $xoff > $ylim - $yoff) { + // Things seems faster (I'm not sure I understand why) + // when the shortest sequence in X. + $flip = TRUE; + list($xoff, $xlim, $yoff, $ylim) = array($yoff, $ylim, $xoff, $xlim); + } + + if ($flip) { + for ($i = $ylim - 1; $i >= $yoff; $i--) { + $ymatches[$this->xv[$i]][] = $i; + } + } + else { + for ($i = $ylim - 1; $i >= $yoff; $i--) { + $ymatches[$this->yv[$i]][] = $i; + } + } + $this->lcs = 0; + $this->seq[0]= $yoff - 1; + $this->in_seq = array(); + $ymids[0] = array(); + + $numer = $xlim - $xoff + $nchunks - 1; + $x = $xoff; + for ($chunk = 0; $chunk < $nchunks; $chunk++) { + if ($chunk > 0) { + for ($i = 0; $i <= $this->lcs; $i++) { + $ymids[$i][$chunk-1] = $this->seq[$i]; + } + } + + $x1 = $xoff + (int)(($numer + ($xlim-$xoff)*$chunk) / $nchunks); + for ( ; $x < $x1; $x++) { + $line = $flip ? $this->yv[$x] : $this->xv[$x]; + if (empty($ymatches[$line])) { + continue; + } + $matches = $ymatches[$line]; + reset($matches); + while (list ($junk, $y) = each($matches)) { + if (empty($this->in_seq[$y])) { + $k = $this->_lcs_pos($y); + USE_ASSERTS && assert($k > 0); + $ymids[$k] = $ymids[$k-1]; + break; + } + } + while (list ($junk, $y) = each($matches)) { + if ($y > $this->seq[$k-1]) { + USE_ASSERTS && assert($y < $this->seq[$k]); + // Optimization: this is a common case: + // next match is just replacing previous match. + $this->in_seq[$this->seq[$k]] = FALSE; + $this->seq[$k] = $y; + $this->in_seq[$y] = 1; + } + elseif (empty($this->in_seq[$y])) { + $k = $this->_lcs_pos($y); + USE_ASSERTS && assert($k > 0); + $ymids[$k] = $ymids[$k-1]; + } + } + } + } + + $seps[] = $flip ? array($yoff, $xoff) : array($xoff, $yoff); + $ymid = $ymids[$this->lcs]; + for ($n = 0; $n < $nchunks - 1; $n++) { + $x1 = $xoff + (int)(($numer + ($xlim - $xoff) * $n) / $nchunks); + $y1 = $ymid[$n] + 1; + $seps[] = $flip ? array($y1, $x1) : array($x1, $y1); + } + $seps[] = $flip ? array($ylim, $xlim) : array($xlim, $ylim); + + return array($this->lcs, $seps); + } + + function _lcs_pos($ypos) { + + $end = $this->lcs; + if ($end == 0 || $ypos > $this->seq[$end]) { + $this->seq[++$this->lcs] = $ypos; + $this->in_seq[$ypos] = 1; + return $this->lcs; + } + + $beg = 1; + while ($beg < $end) { + $mid = (int)(($beg + $end) / 2); + if ($ypos > $this->seq[$mid]) { + $beg = $mid + 1; + } + else { + $end = $mid; + } + } + + USE_ASSERTS && assert($ypos != $this->seq[$end]); + + $this->in_seq[$this->seq[$end]] = FALSE; + $this->seq[$end] = $ypos; + $this->in_seq[$ypos] = 1; + return $end; + } + + /** + * Find LCS of two sequences. + * + * The results are recorded in the vectors $this->{x,y}changed[], by + * storing a 1 in the element for each line that is an insertion + * or deletion (ie. is not in the LCS). + * + * The subsequence of file 0 is [XOFF, XLIM) and likewise for file 1. + * + * Note that XLIM, YLIM are exclusive bounds. + * All line numbers are origin-0 and discarded lines are not counted. + */ + function _compareseq($xoff, $xlim, $yoff, $ylim) { + + // Slide down the bottom initial diagonal. + while ($xoff < $xlim && $yoff < $ylim && $this->xv[$xoff] == $this->yv[$yoff]) { + ++$xoff; + ++$yoff; + } + + // Slide up the top initial diagonal. + while ($xlim > $xoff && $ylim > $yoff && $this->xv[$xlim - 1] == $this->yv[$ylim - 1]) { + --$xlim; + --$ylim; + } + + if ($xoff == $xlim || $yoff == $ylim) { + $lcs = 0; + } + else { + // This is ad hoc but seems to work well. + //$nchunks = sqrt(min($xlim - $xoff, $ylim - $yoff) / 2.5); + //$nchunks = max(2, min(8, (int)$nchunks)); + $nchunks = min(7, $xlim - $xoff, $ylim - $yoff) + 1; + list($lcs, $seps) + = $this->_diag($xoff, $xlim, $yoff, $ylim, $nchunks); + } + + if ($lcs == 0) { + // X and Y sequences have no common subsequence: + // mark all changed. + while ($yoff < $ylim) { + $this->ychanged[$this->yind[$yoff++]] = 1; + } + while ($xoff < $xlim) { + $this->xchanged[$this->xind[$xoff++]] = 1; + } + } + else { + // Use the partitions to split this problem into subproblems. + reset($seps); + $pt1 = $seps[0]; + while ($pt2 = next($seps)) { + $this->_compareseq ($pt1[0], $pt2[0], $pt1[1], $pt2[1]); + $pt1 = $pt2; + } + } + } + + /** + * Adjust inserts/deletes of identical lines to join changes + * as much as possible. + * + * We do something when a run of changed lines include a + * line at one end and has an excluded, identical line at the other. + * We are free to choose which identical line is included. + * `compareseq' usually chooses the one at the beginning, + * but usually it is cleaner to consider the following identical line + * to be the "change". + * + * This is extracted verbatim from analyze.c (GNU diffutils-2.7). + */ + function _shift_boundaries($lines, &$changed, $other_changed) { + $i = 0; + $j = 0; + + USE_ASSERTS && assert('sizeof($lines) == sizeof($changed)'); + $len = sizeof($lines); + $other_len = sizeof($other_changed); + + while (1) { + /* + * Scan forwards to find beginning of another run of changes. + * Also keep track of the corresponding point in the other file. + * + * Throughout this code, $i and $j are adjusted together so that + * the first $i elements of $changed and the first $j elements + * of $other_changed both contain the same number of zeros + * (unchanged lines). + * Furthermore, $j is always kept so that $j == $other_len or + * $other_changed[$j] == FALSE. + */ + while ($j < $other_len && $other_changed[$j]) { + $j++; + } + while ($i < $len && ! $changed[$i]) { + USE_ASSERTS && assert('$j < $other_len && ! $other_changed[$j]'); + $i++; + $j++; + while ($j < $other_len && $other_changed[$j]) { + $j++; + } + } + + if ($i == $len) { + break; + } + $start = $i; + + // Find the end of this run of changes. + while (++$i < $len && $changed[$i]) { + continue; + } + + do { + /* + * Record the length of this run of changes, so that + * we can later determine whether the run has grown. + */ + $runlength = $i - $start; + + /* + * Move the changed region back, so long as the + * previous unchanged line matches the last changed one. + * This merges with previous changed regions. + */ + while ($start > 0 && $lines[$start - 1] == $lines[$i - 1]) { + $changed[--$start] = 1; + $changed[--$i] = FALSE; + while ($start > 0 && $changed[$start - 1]) { + $start--; + } + USE_ASSERTS && assert('$j > 0'); + while ($other_changed[--$j]) { + continue; + } + USE_ASSERTS && assert('$j >= 0 && !$other_changed[$j]'); + } + + /* + * Set CORRESPONDING to the end of the changed run, at the last + * point where it corresponds to a changed run in the other file. + * CORRESPONDING == LEN means no such point has been found. + */ + $corresponding = $j < $other_len ? $i : $len; + + /* + * Move the changed region forward, so long as the + * first changed line matches the following unchanged one. + * This merges with following changed regions. + * Do this second, so that if there are no merges, + * the changed region is moved forward as far as possible. + */ + while ($i < $len && $lines[$start] == $lines[$i]) { + $changed[$start++] = FALSE; + $changed[$i++] = 1; + while ($i < $len && $changed[$i]) { + $i++; + } + USE_ASSERTS && assert('$j < $other_len && ! $other_changed[$j]'); + $j++; + if ($j < $other_len && $other_changed[$j]) { + $corresponding = $i; + while ($j < $other_len && $other_changed[$j]) { + $j++; + } + } + } + } while ($runlength != $i - $start); + + /* + * If possible, move the fully-merged run of changes + * back to a corresponding run in the other file. + */ + while ($corresponding < $i) { + $changed[--$start] = 1; + $changed[--$i] = 0; + USE_ASSERTS && assert('$j > 0'); + while ($other_changed[--$j]) { + continue; + } + USE_ASSERTS && assert('$j >= 0 && !$other_changed[$j]'); + } + } + } +} + +/** + * Class representing a 'diff' between two sequences of strings. + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class Diff { + var $edits; + + /** + * Constructor. + * Computes diff between sequences of strings. + * + * @param $from_lines array An array of strings. + * (Typically these are lines from a file.) + * @param $to_lines array An array of strings. + */ + function Diff($from_lines, $to_lines) { + $eng = new _DiffEngine; + $this->edits = $eng->diff($from_lines, $to_lines); + //$this->_check($from_lines, $to_lines); + } + + /** + * Compute reversed Diff. + * + * SYNOPSIS: + * + * $diff = new Diff($lines1, $lines2); + * $rev = $diff->reverse(); + * @return object A Diff object representing the inverse of the + * original diff. + */ + function reverse() { + $rev = $this; + $rev->edits = array(); + foreach ($this->edits as $edit) { + $rev->edits[] = $edit->reverse(); + } + return $rev; + } + + /** + * Check for empty diff. + * + * @return bool True iff two sequences were identical. + */ + function isEmpty() { + foreach ($this->edits as $edit) { + if ($edit->type != 'copy') { + return FALSE; + } + } + return TRUE; + } + + /** + * Compute the length of the Longest Common Subsequence (LCS). + * + * This is mostly for diagnostic purposed. + * + * @return int The length of the LCS. + */ + function lcs() { + $lcs = 0; + foreach ($this->edits as $edit) { + if ($edit->type == 'copy') { + $lcs += sizeof($edit->orig); + } + } + return $lcs; + } + + /** + * Get the original set of lines. + * + * This reconstructs the $from_lines parameter passed to the + * constructor. + * + * @return array The original sequence of strings. + */ + function orig() { + $lines = array(); + + foreach ($this->edits as $edit) { + if ($edit->orig) { + array_splice($lines, sizeof($lines), 0, $edit->orig); + } + } + return $lines; + } + + /** + * Get the closing set of lines. + * + * This reconstructs the $to_lines parameter passed to the + * constructor. + * + * @return array The sequence of strings. + */ + function closing() { + $lines = array(); + + foreach ($this->edits as $edit) { + if ($edit->closing) { + array_splice($lines, sizeof($lines), 0, $edit->closing); + } + } + return $lines; + } + + /** + * Check a Diff for validity. + * + * This is here only for debugging purposes. + */ + function _check($from_lines, $to_lines) { + if (serialize($from_lines) != serialize($this->orig())) { + trigger_error("Reconstructed original doesn't match", E_USER_ERROR); + } + if (serialize($to_lines) != serialize($this->closing())) { + trigger_error("Reconstructed closing doesn't match", E_USER_ERROR); + } + + $rev = $this->reverse(); + if (serialize($to_lines) != serialize($rev->orig())) { + trigger_error("Reversed original doesn't match", E_USER_ERROR); + } + if (serialize($from_lines) != serialize($rev->closing())) { + trigger_error("Reversed closing doesn't match", E_USER_ERROR); + } + + + $prevtype = 'none'; + foreach ($this->edits as $edit) { + if ( $prevtype == $edit->type ) { + trigger_error("Edit sequence is non-optimal", E_USER_ERROR); + } + $prevtype = $edit->type; + } + + $lcs = $this->lcs(); + trigger_error('Diff okay: LCS = ' . $lcs, E_USER_NOTICE); + } +} + +/** + * FIXME: bad name. + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class MappedDiff extends Diff { + /** + * Constructor. + * + * Computes diff between sequences of strings. + * + * This can be used to compute things like + * case-insensitve diffs, or diffs which ignore + * changes in white-space. + * + * @param $from_lines array An array of strings. + * (Typically these are lines from a file.) + * + * @param $to_lines array An array of strings. + * + * @param $mapped_from_lines array This array should + * have the same size number of elements as $from_lines. + * The elements in $mapped_from_lines and + * $mapped_to_lines are what is actually compared + * when computing the diff. + * + * @param $mapped_to_lines array This array should + * have the same number of elements as $to_lines. + */ + function MappedDiff($from_lines, $to_lines, $mapped_from_lines, $mapped_to_lines) { + + assert(sizeof($from_lines) == sizeof($mapped_from_lines)); + assert(sizeof($to_lines) == sizeof($mapped_to_lines)); + + $this->Diff($mapped_from_lines, $mapped_to_lines); + + $xi = $yi = 0; + for ($i = 0; $i < sizeof($this->edits); $i++) { + $orig = &$this->edits[$i]->orig; + if (is_array($orig)) { + $orig = array_slice($from_lines, $xi, sizeof($orig)); + $xi += sizeof($orig); + } + + $closing = &$this->edits[$i]->closing; + if (is_array($closing)) { + $closing = array_slice($to_lines, $yi, sizeof($closing)); + $yi += sizeof($closing); + } + } + } +} + +/** + * A class to format Diffs + * + * This class formats the diff in classic diff format. + * It is intended that this class be customized via inheritance, + * to obtain fancier outputs. + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class DiffFormatter { + /** + * Should a block header be shown? + */ + var $show_header = TRUE; + + /** + * Number of leading context "lines" to preserve. + * + * This should be left at zero for this class, but subclasses + * may want to set this to other values. + */ + var $leading_context_lines = 0; + + /** + * Number of trailing context "lines" to preserve. + * + * This should be left at zero for this class, but subclasses + * may want to set this to other values. + */ + var $trailing_context_lines = 0; + + /** + * Format a diff. + * + * @param $diff object A Diff object. + * @return string The formatted output. + */ + function format($diff) { + $xi = $yi = 1; + $block = FALSE; + $context = array(); + + $nlead = $this->leading_context_lines; + $ntrail = $this->trailing_context_lines; + + $this->_start_diff(); + + foreach ($diff->edits as $edit) { + if ($edit->type == 'copy') { + if (is_array($block)) { + if (sizeof($edit->orig) <= $nlead + $ntrail) { + $block[] = $edit; + } + else { + if ($ntrail) { + $context = array_slice($edit->orig, 0, $ntrail); + $block[] = new _DiffOp_Copy($context); + } + $this->_block($x0, $ntrail + $xi - $x0, $y0, $ntrail + $yi - $y0, $block); + $block = FALSE; + } + } + $context = $edit->orig; + } + else { + if (! is_array($block)) { + $context = array_slice($context, sizeof($context) - $nlead); + $x0 = $xi - sizeof($context); + $y0 = $yi - sizeof($context); + $block = array(); + if ($context) { + $block[] = new _DiffOp_Copy($context); + } + } + $block[] = $edit; + } + + if ($edit->orig) { + $xi += sizeof($edit->orig); + } + if ($edit->closing) { + $yi += sizeof($edit->closing); + } + } + + if (is_array($block)) { + $this->_block($x0, $xi - $x0, $y0, $yi - $y0, $block); + } + $end = $this->_end_diff(); + + if (!empty($xi)) { + $this->line_stats['counter']['x'] += $xi; + } + if (!empty($yi)) { + $this->line_stats['counter']['y'] += $yi; + } + + return $end; + } + + function _block($xbeg, $xlen, $ybeg, $ylen, &$edits) { + $this->_start_block($this->_block_header($xbeg, $xlen, $ybeg, $ylen)); + foreach ($edits as $edit) { + if ($edit->type == 'copy') { + $this->_context($edit->orig); + } + elseif ($edit->type == 'add') { + $this->_added($edit->closing); + } + elseif ($edit->type == 'delete') { + $this->_deleted($edit->orig); + } + elseif ($edit->type == 'change') { + $this->_changed($edit->orig, $edit->closing); + } + else { + trigger_error('Unknown edit type', E_USER_ERROR); + } + } + $this->_end_block(); + } + + function _start_diff() { + ob_start(); + } + + function _end_diff() { + $val = ob_get_contents(); + ob_end_clean(); + return $val; + } + + function _block_header($xbeg, $xlen, $ybeg, $ylen) { + if ($xlen > 1) { + $xbeg .= "," . ($xbeg + $xlen - 1); + } + if ($ylen > 1) { + $ybeg .= "," . ($ybeg + $ylen - 1); + } + + return $xbeg . ($xlen ? ($ylen ? 'c' : 'd') : 'a') . $ybeg; + } + + function _start_block($header) { + if ($this->show_header) { + echo $header . "\n"; + } + } + + function _end_block() { + } + + function _lines($lines, $prefix = ' ') { + foreach ($lines as $line) { + echo "$prefix $line\n"; + } + } + + function _context($lines) { + $this->_lines($lines); + } + + function _added($lines) { + $this->_lines($lines, '>'); + } + function _deleted($lines) { + $this->_lines($lines, '<'); + } + + function _changed($orig, $closing) { + $this->_deleted($orig); + echo "---\n"; + $this->_added($closing); + } +} + + +/** + * Additions by Axel Boldt follow, partly taken from diff.php, phpwiki-1.3.3 + * + */ + +define('NBSP', ' '); // iso-8859-x non-breaking space. + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _HWLDF_WordAccumulator { + function _HWLDF_WordAccumulator() { + $this->_lines = array(); + $this->_line = ''; + $this->_group = ''; + $this->_tag = ''; + } + + function _flushGroup($new_tag) { + if ($this->_group !== '') { + if ($this->_tag == 'mark') { + $this->_line .= '' . check_plain($this->_group) . ''; + } + else { + $this->_line .= check_plain($this->_group); + } + } + $this->_group = ''; + $this->_tag = $new_tag; + } + + function _flushLine($new_tag) { + $this->_flushGroup($new_tag); + if ($this->_line != '') { + array_push($this->_lines, $this->_line); + } + else { + // make empty lines visible by inserting an NBSP + array_push($this->_lines, NBSP); + } + $this->_line = ''; + } + + function addWords($words, $tag = '') { + if ($tag != $this->_tag) { + $this->_flushGroup($tag); + } + foreach ($words as $word) { + // new-line should only come as first char of word. + if ($word == '') { + continue; + } + if ($word[0] == "\n") { + $this->_flushLine($tag); + $word = drupal_substr($word, 1); + } + assert(!strstr($word, "\n")); + $this->_group .= $word; + } + } + + function getLines() { + $this->_flushLine('~done'); + return $this->_lines; + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class WordLevelDiff extends MappedDiff { + function MAX_LINE_LENGTH() { + return 10000; + } + + function WordLevelDiff($orig_lines, $closing_lines) { + list($orig_words, $orig_stripped) = $this->_split($orig_lines); + list($closing_words, $closing_stripped) = $this->_split($closing_lines); + + $this->MappedDiff($orig_words, $closing_words, $orig_stripped, $closing_stripped); + } + + function _split($lines) { + $words = array(); + $stripped = array(); + $first = TRUE; + foreach ($lines as $line) { + // If the line is too long, just pretend the entire line is one big word + // This prevents resource exhaustion problems + if ( $first ) { + $first = FALSE; + } + else { + $words[] = "\n"; + $stripped[] = "\n"; + } + if ( drupal_strlen( $line ) > $this->MAX_LINE_LENGTH() ) { + $words[] = $line; + $stripped[] = $line; + } + else { + if (preg_match_all('/ ( [^\S\n]+ | [0-9_A-Za-z\x80-\xff]+ | . ) (?: (?!< \n) [^\S\n])? /xs', $line, $m)) { + $words = array_merge($words, $m[0]); + $stripped = array_merge($stripped, $m[1]); + } + } + } + return array($words, $stripped); + } + + function orig() { + $orig = new _HWLDF_WordAccumulator; + + foreach ($this->edits as $edit) { + if ($edit->type == 'copy') { + $orig->addWords($edit->orig); + } + elseif ($edit->orig) { + $orig->addWords($edit->orig, 'mark'); + } + } + $lines = $orig->getLines(); + return $lines; + } + + function closing() { + $closing = new _HWLDF_WordAccumulator; + + foreach ($this->edits as $edit) { + if ($edit->type == 'copy') { + $closing->addWords($edit->closing); + } + elseif ($edit->closing) { + $closing->addWords($edit->closing, 'mark'); + } + } + $lines = $closing->getLines(); + return $lines; + } +} + +/** + * Diff formatter which uses Drupal theme functions. + * @private + * @subpackage DifferenceEngine + */ +class DrupalDiffFormatter extends DiffFormatter { + + var $rows; + var $line_stats = array( + 'counter' => array('x' => 0, 'y' => 0), + 'offset' => array('x' => 0, 'y' => 0), + ); + + function DrupalDiffFormatter() { + $this->leading_context_lines = \Drupal::config('diff.settings')->get('diff_context_lines_leading'); + $this->trailing_context_lines = \Drupal::config('diff.settings')->get('diff_context_lines_trailing'); + } + + function _start_diff() { + $this->rows = array(); + } + + function _end_diff() { + return $this->rows; + } + + function _block_header($xbeg, $xlen, $ybeg, $ylen) { + return array( + array( + 'data' => _theme('diff_header_line', array('lineno' => $xbeg + $this->line_stats['offset']['x'])), + 'colspan' => 2, + ), + array( + 'data' => _theme('diff_header_line', array('lineno' => $ybeg + $this->line_stats['offset']['y'])), + 'colspan' => 2, + ) + ); + } + + function _start_block($header) { + if ($this->show_header) { + $this->rows[] = $header; + } + } + + function _end_block() { + } + + function _lines($lines, $prefix=' ', $color='white') { + } + + /** + * Note: you should HTML-escape parameter before calling this. + */ + function addedLine($line) { + return array( + array( + 'data' => '+', + 'class' => 'diff-marker', + ), + array( + 'data' => _theme('diff_content_line', array('line' => $line)), + 'class' => 'diff-context diff-addedline', + ) + ); + } + + /** + * Note: you should HTML-escape parameter before calling this. + */ + function deletedLine($line) { + return array( + array( + 'data' => '-', + 'class' => 'diff-marker', + ), + array( + 'data' => _theme('diff_content_line', array('line' => $line)), + 'class' => 'diff-context diff-deletedline', + ) + ); + } + + /** + * Note: you should HTML-escape parameter before calling this. + */ + function contextLine($line) { + return array( + ' ', + array( + 'data' => _theme('diff_content_line', array('line' => $line)), + 'class' => 'diff-context', + ) + ); + } + + function emptyLine() { + return array( + ' ', + _theme('diff_empty_line', array('line' => ' ')), + ); + } + + function _added($lines) { + foreach ($lines as $line) { + $this->rows[] = array_merge($this->emptyLine(), $this->addedLine(check_plain($line))); + } + } + + function _deleted($lines) { + foreach ($lines as $line) { + $this->rows[] = array_merge($this->deletedLine(check_plain($line)), $this->emptyLine()); + } + } + + function _context($lines) { + foreach ($lines as $line) { + $this->rows[] = array_merge($this->contextLine(check_plain($line)), $this->contextLine(check_plain($line))); + } + } + + function _changed($orig, $closing) { + $diff = new WordLevelDiff($orig, $closing); + $del = $diff->orig(); + $add = $diff->closing(); + + // Notice that WordLevelDiff returns HTML-escaped output. + // Hence, we will be calling addedLine/deletedLine without HTML-escaping. + + while ($line = array_shift($del)) { + $aline = array_shift( $add ); + $this->rows[] = array_merge($this->deletedLine($line), isset($aline) ? $this->addedLine($aline) : $this->emptyLine()); + } + foreach ($add as $line) { // If any leftovers + $this->rows[] = array_merge($this->emptyLine(), $this->addedLine($line)); + } + } +} + +/** + * Drupal inline Diff formatter. + * @private + * @subpackage DifferenceEngine + */ +class DrupalDiffInline { + var $a; + var $b; + + /** + * Constructor. + */ + function __construct($a, $b) { + $this->a = $a; + $this->b = $b; + } + + /** + * Render differences inline using HTML markup. + */ + function render() { + $a = preg_split('/(<[^>]+?>| )/', $this->a, -1, PREG_SPLIT_DELIM_CAPTURE); + $b = preg_split('/(<[^>]+?>| )/', $this->b, -1, PREG_SPLIT_DELIM_CAPTURE); + $diff = new Diff($a, $b); + $diff->edits = $this->process_edits($diff->edits); + + // Assemble highlighted output + $output = ''; + foreach ($diff->edits as $chunk) { + switch ($chunk->type) { + case 'copy': + $output .= implode('', $chunk->closing); + break; + case 'delete': + foreach ($chunk->orig as $i => $piece) { + if (strpos($piece, '<') === 0 && drupal_substr($piece, drupal_strlen($piece) - 1) === '>') { + $output .= $piece; + } + else { + $output .= _theme('diff_inline_chunk', array('text' => $piece, 'type' => $chunk->type)); + } + } + break; + default: + $chunk->closing = $this->process_chunk($chunk->closing); + foreach ($chunk->closing as $i => $piece) { + if ($piece === ' ' || (strpos($piece, '<') === 0 && drupal_substr($piece, drupal_strlen($piece) - 1) === '>' && drupal_strtolower(drupal_substr($piece, 1, 3)) != 'img')) { + $output .= $piece; + } + else { + $output .= _theme('diff_inline_chunk', array('text' => $piece, 'type' => $chunk->type)); + } + } + break; + } + } + return $output; + } + + /** + * Merge chunk segments between tag delimiters. + */ + function process_chunk($chunk) { + $processed = array(); + $j = 0; + foreach ($chunk as $i => $piece) { + $next = isset($chunk[$i+1]) ? $chunk[$i+1] : NULL; + if (!isset($processed[$j])) { + $processed[$j] = ''; + } + if (strpos($piece, '<') === 0 && drupal_substr($piece, drupal_strlen($piece) - 1) === '>') { + $processed[$j] = $piece; + $j++; + } + elseif (isset($next) && strpos($next, '<') === 0 && drupal_substr($next, drupal_strlen($next) - 1) === '>') { + $processed[$j] .= $piece; + $j++; + } + else { + $processed[$j] .= $piece; + } + } + return $processed; + } + + /** + * Merge copy and equivalent edits into intelligible chunks. + */ + function process_edits($edits) { + $processed = array(); + $current = array_shift($edits); + + // Make two passes -- first merge space delimiter copies back into their originals. + while ($chunk = array_shift($edits)) { + if ($chunk->type == 'copy' && $chunk->orig === array(' ')) { + $current->orig = array_merge((array) $current->orig, (array) $chunk->orig); + $current->closing = array_merge((array) $current->closing, (array) $chunk->closing); + } + else { + $processed[] = $current; + $current = $chunk; + } + } + $processed[] = $current; + + // Initial setup + $edits = $processed; + $processed = array(); + $current = array_shift($edits); + + // Second, merge equivalent chunks into each other. + while ($chunk = array_shift($edits)) { + if ($current->type == $chunk->type) { + $current->orig = array_merge((array) $current->orig, (array) $chunk->orig); + $current->closing = array_merge((array) $current->closing, (array) $chunk->closing); + } + else { + $processed[] = $current; + $current = $chunk; + } + } + $processed[] = $current; + + return $processed; + } +} diff --git a/src/_DiffEngine.php b/src/_DiffEngine.php new file mode 100644 index 0000000..f0c0d51 --- /dev/null +++ b/src/_DiffEngine.php @@ -0,0 +1,1355 @@ + + * You may copy this code freely under the conditions of the GPL. + */ + +define('USE_ASSERTS', FALSE); + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp { + var $type; + var $orig; + var $closing; + + function reverse() { + trigger_error('pure virtual', E_USER_ERROR); + } + + function norig() { + return $this->orig ? sizeof($this->orig) : 0; + } + + function nclosing() { + return $this->closing ? sizeof($this->closing) : 0; + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Copy extends _DiffOp { + var $type = 'copy'; + + function _DiffOp_Copy($orig, $closing = FALSE) { + if (!is_array($closing)) { + $closing = $orig; + } + $this->orig = $orig; + $this->closing = $closing; + } + + function reverse() { + return new _DiffOp_Copy($this->closing, $this->orig); + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Delete extends _DiffOp { + var $type = 'delete'; + + function _DiffOp_Delete($lines) { + $this->orig = $lines; + $this->closing = FALSE; + } + + function reverse() { + return new _DiffOp_Add($this->orig); + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Add extends _DiffOp { + var $type = 'add'; + + function _DiffOp_Add($lines) { + $this->closing = $lines; + $this->orig = FALSE; + } + + function reverse() { + return new _DiffOp_Delete($this->closing); + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Change extends _DiffOp { + var $type = 'change'; + + function _DiffOp_Change($orig, $closing) { + $this->orig = $orig; + $this->closing = $closing; + } + + function reverse() { + return new _DiffOp_Change($this->closing, $this->orig); + } +} + + +/** + * Class used internally by Diff to actually compute the diffs. + * + * The algorithm used here is mostly lifted from the perl module + * Algorithm::Diff (version 1.06) by Ned Konz, which is available at: + * http://www.perl.com/CPAN/authors/id/N/NE/NEDKONZ/Algorithm-Diff-1.06.zip + * + * More ideas are taken from: + * http://www.ics.uci.edu/~eppstein/161/960229.html + * + * Some ideas are (and a bit of code) are from from analyze.c, from GNU + * diffutils-2.7, which can be found at: + * ftp://gnudist.gnu.org/pub/gnu/diffutils/diffutils-2.7.tar.gz + * + * closingly, some ideas (subdivision by NCHUNKS > 2, and some optimizations) + * are my own. + * + * Line length limits for robustness added by Tim Starling, 2005-08-31 + * + * @author Geoffrey T. Dairiki, Tim Starling + * @private + * @subpackage DifferenceEngine + */ +class _DiffEngine { + function MAX_XREF_LENGTH() { + return 10000; + } + + function diff($from_lines, $to_lines) { + + $n_from = sizeof($from_lines); + $n_to = sizeof($to_lines); + + $this->xchanged = $this->ychanged = array(); + $this->xv = $this->yv = array(); + $this->xind = $this->yind = array(); + unset($this->seq); + unset($this->in_seq); + unset($this->lcs); + + // Skip leading common lines. + for ($skip = 0; $skip < $n_from && $skip < $n_to; $skip++) { + if ($from_lines[$skip] !== $to_lines[$skip]) { + break; + } + $this->xchanged[$skip] = $this->ychanged[$skip] = FALSE; + } + // Skip trailing common lines. + $xi = $n_from; + $yi = $n_to; + for ($endskip = 0; --$xi > $skip && --$yi > $skip; $endskip++) { + if ($from_lines[$xi] !== $to_lines[$yi]) { + break; + } + $this->xchanged[$xi] = $this->ychanged[$yi] = FALSE; + } + + // Ignore lines which do not exist in both files. + for ($xi = $skip; $xi < $n_from - $endskip; $xi++) { + $xhash[$this->_line_hash($from_lines[$xi])] = 1; + } + + for ($yi = $skip; $yi < $n_to - $endskip; $yi++) { + $line = $to_lines[$yi]; + if ($this->ychanged[$yi] = empty($xhash[$this->_line_hash($line)])) { + continue; + } + $yhash[$this->_line_hash($line)] = 1; + $this->yv[] = $line; + $this->yind[] = $yi; + } + for ($xi = $skip; $xi < $n_from - $endskip; $xi++) { + $line = $from_lines[$xi]; + if ($this->xchanged[$xi] = empty($yhash[$this->_line_hash($line)])) { + continue; + } + $this->xv[] = $line; + $this->xind[] = $xi; + } + + // Find the LCS. + $this->_compareseq(0, sizeof($this->xv), 0, sizeof($this->yv)); + + // Merge edits when possible + $this->_shift_boundaries($from_lines, $this->xchanged, $this->ychanged); + $this->_shift_boundaries($to_lines, $this->ychanged, $this->xchanged); + + // Compute the edit operations. + $edits = array(); + $xi = $yi = 0; + while ($xi < $n_from || $yi < $n_to) { + USE_ASSERTS && assert($yi < $n_to || $this->xchanged[$xi]); + USE_ASSERTS && assert($xi < $n_from || $this->ychanged[$yi]); + + // Skip matching "snake". + $copy = array(); + while ( $xi < $n_from && $yi < $n_to && !$this->xchanged[$xi] && !$this->ychanged[$yi]) { + $copy[] = $from_lines[$xi++]; + ++$yi; + } + if ($copy) { + $edits[] = new _DiffOp_Copy($copy); + } + // Find deletes & adds. + $delete = array(); + while ($xi < $n_from && $this->xchanged[$xi]) { + $_fl = $from_lines[$xi++]; + if (strlen($_fl)) { + $delete[] = $_fl; + } + } + $add = array(); + while ($yi < $n_to && $this->ychanged[$yi]) { + $_tl = $to_lines[$yi++]; + if (strlen($_tl)) { + $add[] = $_tl; + } + } + if ($delete && $add) { + $edits[] = new _DiffOp_Change($delete, $add); + } + elseif ($delete) { + $edits[] = new _DiffOp_Delete($delete); + } + elseif ($add) { + $edits[] = new _DiffOp_Add($add); + } + } + return $edits; + } + + /** + * Returns the whole line if it's small enough, or the MD5 hash otherwise. + */ + function _line_hash($line) { + if (drupal_strlen($line) > $this->MAX_XREF_LENGTH()) { + return md5($line); + } + else { + return $line; + } + } + + + /** + * Divide the Largest Common Subsequence (LCS) of the sequences + * [XOFF, XLIM) and [YOFF, YLIM) into NCHUNKS approximately equally + * sized segments. + * + * Returns (LCS, PTS). LCS is the length of the LCS. PTS is an + * array of NCHUNKS+1 (X, Y) indexes giving the diving points between + * sub sequences. The first sub-sequence is contained in [X0, X1), + * [Y0, Y1), the second in [X1, X2), [Y1, Y2) and so on. Note + * that (X0, Y0) == (XOFF, YOFF) and + * (X[NCHUNKS], Y[NCHUNKS]) == (XLIM, YLIM). + * + * This function assumes that the first lines of the specified portions + * of the two files do not match, and likewise that the last lines do not + * match. The caller must trim matching lines from the beginning and end + * of the portions it is going to specify. + */ + function _diag($xoff, $xlim, $yoff, $ylim, $nchunks) { + $flip = FALSE; + + if ($xlim - $xoff > $ylim - $yoff) { + // Things seems faster (I'm not sure I understand why) + // when the shortest sequence in X. + $flip = TRUE; + list($xoff, $xlim, $yoff, $ylim) = array($yoff, $ylim, $xoff, $xlim); + } + + if ($flip) { + for ($i = $ylim - 1; $i >= $yoff; $i--) { + $ymatches[$this->xv[$i]][] = $i; + } + } + else { + for ($i = $ylim - 1; $i >= $yoff; $i--) { + $ymatches[$this->yv[$i]][] = $i; + } + } + $this->lcs = 0; + $this->seq[0]= $yoff - 1; + $this->in_seq = array(); + $ymids[0] = array(); + + $numer = $xlim - $xoff + $nchunks - 1; + $x = $xoff; + for ($chunk = 0; $chunk < $nchunks; $chunk++) { + if ($chunk > 0) { + for ($i = 0; $i <= $this->lcs; $i++) { + $ymids[$i][$chunk-1] = $this->seq[$i]; + } + } + + $x1 = $xoff + (int)(($numer + ($xlim-$xoff)*$chunk) / $nchunks); + for ( ; $x < $x1; $x++) { + $line = $flip ? $this->yv[$x] : $this->xv[$x]; + if (empty($ymatches[$line])) { + continue; + } + $matches = $ymatches[$line]; + reset($matches); + while (list ($junk, $y) = each($matches)) { + if (empty($this->in_seq[$y])) { + $k = $this->_lcs_pos($y); + USE_ASSERTS && assert($k > 0); + $ymids[$k] = $ymids[$k-1]; + break; + } + } + while (list ($junk, $y) = each($matches)) { + if ($y > $this->seq[$k-1]) { + USE_ASSERTS && assert($y < $this->seq[$k]); + // Optimization: this is a common case: + // next match is just replacing previous match. + $this->in_seq[$this->seq[$k]] = FALSE; + $this->seq[$k] = $y; + $this->in_seq[$y] = 1; + } + elseif (empty($this->in_seq[$y])) { + $k = $this->_lcs_pos($y); + USE_ASSERTS && assert($k > 0); + $ymids[$k] = $ymids[$k-1]; + } + } + } + } + + $seps[] = $flip ? array($yoff, $xoff) : array($xoff, $yoff); + $ymid = $ymids[$this->lcs]; + for ($n = 0; $n < $nchunks - 1; $n++) { + $x1 = $xoff + (int)(($numer + ($xlim - $xoff) * $n) / $nchunks); + $y1 = $ymid[$n] + 1; + $seps[] = $flip ? array($y1, $x1) : array($x1, $y1); + } + $seps[] = $flip ? array($ylim, $xlim) : array($xlim, $ylim); + + return array($this->lcs, $seps); + } + + function _lcs_pos($ypos) { + + $end = $this->lcs; + if ($end == 0 || $ypos > $this->seq[$end]) { + $this->seq[++$this->lcs] = $ypos; + $this->in_seq[$ypos] = 1; + return $this->lcs; + } + + $beg = 1; + while ($beg < $end) { + $mid = (int)(($beg + $end) / 2); + if ($ypos > $this->seq[$mid]) { + $beg = $mid + 1; + } + else { + $end = $mid; + } + } + + USE_ASSERTS && assert($ypos != $this->seq[$end]); + + $this->in_seq[$this->seq[$end]] = FALSE; + $this->seq[$end] = $ypos; + $this->in_seq[$ypos] = 1; + return $end; + } + + /** + * Find LCS of two sequences. + * + * The results are recorded in the vectors $this->{x,y}changed[], by + * storing a 1 in the element for each line that is an insertion + * or deletion (ie. is not in the LCS). + * + * The subsequence of file 0 is [XOFF, XLIM) and likewise for file 1. + * + * Note that XLIM, YLIM are exclusive bounds. + * All line numbers are origin-0 and discarded lines are not counted. + */ + function _compareseq($xoff, $xlim, $yoff, $ylim) { + + // Slide down the bottom initial diagonal. + while ($xoff < $xlim && $yoff < $ylim && $this->xv[$xoff] == $this->yv[$yoff]) { + ++$xoff; + ++$yoff; + } + + // Slide up the top initial diagonal. + while ($xlim > $xoff && $ylim > $yoff && $this->xv[$xlim - 1] == $this->yv[$ylim - 1]) { + --$xlim; + --$ylim; + } + + if ($xoff == $xlim || $yoff == $ylim) { + $lcs = 0; + } + else { + // This is ad hoc but seems to work well. + //$nchunks = sqrt(min($xlim - $xoff, $ylim - $yoff) / 2.5); + //$nchunks = max(2, min(8, (int)$nchunks)); + $nchunks = min(7, $xlim - $xoff, $ylim - $yoff) + 1; + list($lcs, $seps) + = $this->_diag($xoff, $xlim, $yoff, $ylim, $nchunks); + } + + if ($lcs == 0) { + // X and Y sequences have no common subsequence: + // mark all changed. + while ($yoff < $ylim) { + $this->ychanged[$this->yind[$yoff++]] = 1; + } + while ($xoff < $xlim) { + $this->xchanged[$this->xind[$xoff++]] = 1; + } + } + else { + // Use the partitions to split this problem into subproblems. + reset($seps); + $pt1 = $seps[0]; + while ($pt2 = next($seps)) { + $this->_compareseq ($pt1[0], $pt2[0], $pt1[1], $pt2[1]); + $pt1 = $pt2; + } + } + } + + /** + * Adjust inserts/deletes of identical lines to join changes + * as much as possible. + * + * We do something when a run of changed lines include a + * line at one end and has an excluded, identical line at the other. + * We are free to choose which identical line is included. + * `compareseq' usually chooses the one at the beginning, + * but usually it is cleaner to consider the following identical line + * to be the "change". + * + * This is extracted verbatim from analyze.c (GNU diffutils-2.7). + */ + function _shift_boundaries($lines, &$changed, $other_changed) { + $i = 0; + $j = 0; + + USE_ASSERTS && assert('sizeof($lines) == sizeof($changed)'); + $len = sizeof($lines); + $other_len = sizeof($other_changed); + + while (1) { + /* + * Scan forwards to find beginning of another run of changes. + * Also keep track of the corresponding point in the other file. + * + * Throughout this code, $i and $j are adjusted together so that + * the first $i elements of $changed and the first $j elements + * of $other_changed both contain the same number of zeros + * (unchanged lines). + * Furthermore, $j is always kept so that $j == $other_len or + * $other_changed[$j] == FALSE. + */ + while ($j < $other_len && $other_changed[$j]) { + $j++; + } + while ($i < $len && ! $changed[$i]) { + USE_ASSERTS && assert('$j < $other_len && ! $other_changed[$j]'); + $i++; + $j++; + while ($j < $other_len && $other_changed[$j]) { + $j++; + } + } + + if ($i == $len) { + break; + } + $start = $i; + + // Find the end of this run of changes. + while (++$i < $len && $changed[$i]) { + continue; + } + + do { + /* + * Record the length of this run of changes, so that + * we can later determine whether the run has grown. + */ + $runlength = $i - $start; + + /* + * Move the changed region back, so long as the + * previous unchanged line matches the last changed one. + * This merges with previous changed regions. + */ + while ($start > 0 && $lines[$start - 1] == $lines[$i - 1]) { + $changed[--$start] = 1; + $changed[--$i] = FALSE; + while ($start > 0 && $changed[$start - 1]) { + $start--; + } + USE_ASSERTS && assert('$j > 0'); + while ($other_changed[--$j]) { + continue; + } + USE_ASSERTS && assert('$j >= 0 && !$other_changed[$j]'); + } + + /* + * Set CORRESPONDING to the end of the changed run, at the last + * point where it corresponds to a changed run in the other file. + * CORRESPONDING == LEN means no such point has been found. + */ + $corresponding = $j < $other_len ? $i : $len; + + /* + * Move the changed region forward, so long as the + * first changed line matches the following unchanged one. + * This merges with following changed regions. + * Do this second, so that if there are no merges, + * the changed region is moved forward as far as possible. + */ + while ($i < $len && $lines[$start] == $lines[$i]) { + $changed[$start++] = FALSE; + $changed[$i++] = 1; + while ($i < $len && $changed[$i]) { + $i++; + } + USE_ASSERTS && assert('$j < $other_len && ! $other_changed[$j]'); + $j++; + if ($j < $other_len && $other_changed[$j]) { + $corresponding = $i; + while ($j < $other_len && $other_changed[$j]) { + $j++; + } + } + } + } while ($runlength != $i - $start); + + /* + * If possible, move the fully-merged run of changes + * back to a corresponding run in the other file. + */ + while ($corresponding < $i) { + $changed[--$start] = 1; + $changed[--$i] = 0; + USE_ASSERTS && assert('$j > 0'); + while ($other_changed[--$j]) { + continue; + } + USE_ASSERTS && assert('$j >= 0 && !$other_changed[$j]'); + } + } + } +} + +/** + * Class representing a 'diff' between two sequences of strings. + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class Diff { + var $edits; + + /** + * Constructor. + * Computes diff between sequences of strings. + * + * @param $from_lines array An array of strings. + * (Typically these are lines from a file.) + * @param $to_lines array An array of strings. + */ + function Diff($from_lines, $to_lines) { + $eng = new _DiffEngine; + $this->edits = $eng->diff($from_lines, $to_lines); + //$this->_check($from_lines, $to_lines); + } + + /** + * Compute reversed Diff. + * + * SYNOPSIS: + * + * $diff = new Diff($lines1, $lines2); + * $rev = $diff->reverse(); + * @return object A Diff object representing the inverse of the + * original diff. + */ + function reverse() { + $rev = $this; + $rev->edits = array(); + foreach ($this->edits as $edit) { + $rev->edits[] = $edit->reverse(); + } + return $rev; + } + + /** + * Check for empty diff. + * + * @return bool True iff two sequences were identical. + */ + function isEmpty() { + foreach ($this->edits as $edit) { + if ($edit->type != 'copy') { + return FALSE; + } + } + return TRUE; + } + + /** + * Compute the length of the Longest Common Subsequence (LCS). + * + * This is mostly for diagnostic purposed. + * + * @return int The length of the LCS. + */ + function lcs() { + $lcs = 0; + foreach ($this->edits as $edit) { + if ($edit->type == 'copy') { + $lcs += sizeof($edit->orig); + } + } + return $lcs; + } + + /** + * Get the original set of lines. + * + * This reconstructs the $from_lines parameter passed to the + * constructor. + * + * @return array The original sequence of strings. + */ + function orig() { + $lines = array(); + + foreach ($this->edits as $edit) { + if ($edit->orig) { + array_splice($lines, sizeof($lines), 0, $edit->orig); + } + } + return $lines; + } + + /** + * Get the closing set of lines. + * + * This reconstructs the $to_lines parameter passed to the + * constructor. + * + * @return array The sequence of strings. + */ + function closing() { + $lines = array(); + + foreach ($this->edits as $edit) { + if ($edit->closing) { + array_splice($lines, sizeof($lines), 0, $edit->closing); + } + } + return $lines; + } + + /** + * Check a Diff for validity. + * + * This is here only for debugging purposes. + */ + function _check($from_lines, $to_lines) { + if (serialize($from_lines) != serialize($this->orig())) { + trigger_error("Reconstructed original doesn't match", E_USER_ERROR); + } + if (serialize($to_lines) != serialize($this->closing())) { + trigger_error("Reconstructed closing doesn't match", E_USER_ERROR); + } + + $rev = $this->reverse(); + if (serialize($to_lines) != serialize($rev->orig())) { + trigger_error("Reversed original doesn't match", E_USER_ERROR); + } + if (serialize($from_lines) != serialize($rev->closing())) { + trigger_error("Reversed closing doesn't match", E_USER_ERROR); + } + + + $prevtype = 'none'; + foreach ($this->edits as $edit) { + if ( $prevtype == $edit->type ) { + trigger_error("Edit sequence is non-optimal", E_USER_ERROR); + } + $prevtype = $edit->type; + } + + $lcs = $this->lcs(); + trigger_error('Diff okay: LCS = ' . $lcs, E_USER_NOTICE); + } +} + +/** + * FIXME: bad name. + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class MappedDiff extends Diff { + /** + * Constructor. + * + * Computes diff between sequences of strings. + * + * This can be used to compute things like + * case-insensitve diffs, or diffs which ignore + * changes in white-space. + * + * @param $from_lines array An array of strings. + * (Typically these are lines from a file.) + * + * @param $to_lines array An array of strings. + * + * @param $mapped_from_lines array This array should + * have the same size number of elements as $from_lines. + * The elements in $mapped_from_lines and + * $mapped_to_lines are what is actually compared + * when computing the diff. + * + * @param $mapped_to_lines array This array should + * have the same number of elements as $to_lines. + */ + function MappedDiff($from_lines, $to_lines, $mapped_from_lines, $mapped_to_lines) { + + assert(sizeof($from_lines) == sizeof($mapped_from_lines)); + assert(sizeof($to_lines) == sizeof($mapped_to_lines)); + + $this->Diff($mapped_from_lines, $mapped_to_lines); + + $xi = $yi = 0; + for ($i = 0; $i < sizeof($this->edits); $i++) { + $orig = &$this->edits[$i]->orig; + if (is_array($orig)) { + $orig = array_slice($from_lines, $xi, sizeof($orig)); + $xi += sizeof($orig); + } + + $closing = &$this->edits[$i]->closing; + if (is_array($closing)) { + $closing = array_slice($to_lines, $yi, sizeof($closing)); + $yi += sizeof($closing); + } + } + } +} + +/** + * A class to format Diffs + * + * This class formats the diff in classic diff format. + * It is intended that this class be customized via inheritance, + * to obtain fancier outputs. + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class DiffFormatter { + /** + * Should a block header be shown? + */ + var $show_header = TRUE; + + /** + * Number of leading context "lines" to preserve. + * + * This should be left at zero for this class, but subclasses + * may want to set this to other values. + */ + var $leading_context_lines = 0; + + /** + * Number of trailing context "lines" to preserve. + * + * This should be left at zero for this class, but subclasses + * may want to set this to other values. + */ + var $trailing_context_lines = 0; + + /** + * Format a diff. + * + * @param $diff object A Diff object. + * @return string The formatted output. + */ + function format($diff) { + $xi = $yi = 1; + $block = FALSE; + $context = array(); + + $nlead = $this->leading_context_lines; + $ntrail = $this->trailing_context_lines; + + $this->_start_diff(); + + foreach ($diff->edits as $edit) { + if ($edit->type == 'copy') { + if (is_array($block)) { + if (sizeof($edit->orig) <= $nlead + $ntrail) { + $block[] = $edit; + } + else { + if ($ntrail) { + $context = array_slice($edit->orig, 0, $ntrail); + $block[] = new _DiffOp_Copy($context); + } + $this->_block($x0, $ntrail + $xi - $x0, $y0, $ntrail + $yi - $y0, $block); + $block = FALSE; + } + } + $context = $edit->orig; + } + else { + if (! is_array($block)) { + $context = array_slice($context, sizeof($context) - $nlead); + $x0 = $xi - sizeof($context); + $y0 = $yi - sizeof($context); + $block = array(); + if ($context) { + $block[] = new _DiffOp_Copy($context); + } + } + $block[] = $edit; + } + + if ($edit->orig) { + $xi += sizeof($edit->orig); + } + if ($edit->closing) { + $yi += sizeof($edit->closing); + } + } + + if (is_array($block)) { + $this->_block($x0, $xi - $x0, $y0, $yi - $y0, $block); + } + $end = $this->_end_diff(); + + if (!empty($xi)) { + $this->line_stats['counter']['x'] += $xi; + } + if (!empty($yi)) { + $this->line_stats['counter']['y'] += $yi; + } + + return $end; + } + + function _block($xbeg, $xlen, $ybeg, $ylen, &$edits) { + $this->_start_block($this->_block_header($xbeg, $xlen, $ybeg, $ylen)); + foreach ($edits as $edit) { + if ($edit->type == 'copy') { + $this->_context($edit->orig); + } + elseif ($edit->type == 'add') { + $this->_added($edit->closing); + } + elseif ($edit->type == 'delete') { + $this->_deleted($edit->orig); + } + elseif ($edit->type == 'change') { + $this->_changed($edit->orig, $edit->closing); + } + else { + trigger_error('Unknown edit type', E_USER_ERROR); + } + } + $this->_end_block(); + } + + function _start_diff() { + ob_start(); + } + + function _end_diff() { + $val = ob_get_contents(); + ob_end_clean(); + return $val; + } + + function _block_header($xbeg, $xlen, $ybeg, $ylen) { + if ($xlen > 1) { + $xbeg .= "," . ($xbeg + $xlen - 1); + } + if ($ylen > 1) { + $ybeg .= "," . ($ybeg + $ylen - 1); + } + + return $xbeg . ($xlen ? ($ylen ? 'c' : 'd') : 'a') . $ybeg; + } + + function _start_block($header) { + if ($this->show_header) { + echo $header . "\n"; + } + } + + function _end_block() { + } + + function _lines($lines, $prefix = ' ') { + foreach ($lines as $line) { + echo "$prefix $line\n"; + } + } + + function _context($lines) { + $this->_lines($lines); + } + + function _added($lines) { + $this->_lines($lines, '>'); + } + function _deleted($lines) { + $this->_lines($lines, '<'); + } + + function _changed($orig, $closing) { + $this->_deleted($orig); + echo "---\n"; + $this->_added($closing); + } +} + + +/** + * Additions by Axel Boldt follow, partly taken from diff.php, phpwiki-1.3.3 + * + */ + +define('NBSP', ' '); // iso-8859-x non-breaking space. + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _HWLDF_WordAccumulator { + function _HWLDF_WordAccumulator() { + $this->_lines = array(); + $this->_line = ''; + $this->_group = ''; + $this->_tag = ''; + } + + function _flushGroup($new_tag) { + if ($this->_group !== '') { + if ($this->_tag == 'mark') { + $this->_line .= '' . check_plain($this->_group) . ''; + } + else { + $this->_line .= check_plain($this->_group); + } + } + $this->_group = ''; + $this->_tag = $new_tag; + } + + function _flushLine($new_tag) { + $this->_flushGroup($new_tag); + if ($this->_line != '') { + array_push($this->_lines, $this->_line); + } + else { + // make empty lines visible by inserting an NBSP + array_push($this->_lines, NBSP); + } + $this->_line = ''; + } + + function addWords($words, $tag = '') { + if ($tag != $this->_tag) { + $this->_flushGroup($tag); + } + foreach ($words as $word) { + // new-line should only come as first char of word. + if ($word == '') { + continue; + } + if ($word[0] == "\n") { + $this->_flushLine($tag); + $word = drupal_substr($word, 1); + } + assert(!strstr($word, "\n")); + $this->_group .= $word; + } + } + + function getLines() { + $this->_flushLine('~done'); + return $this->_lines; + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class WordLevelDiff extends MappedDiff { + function MAX_LINE_LENGTH() { + return 10000; + } + + function WordLevelDiff($orig_lines, $closing_lines) { + list($orig_words, $orig_stripped) = $this->_split($orig_lines); + list($closing_words, $closing_stripped) = $this->_split($closing_lines); + + $this->MappedDiff($orig_words, $closing_words, $orig_stripped, $closing_stripped); + } + + function _split($lines) { + $words = array(); + $stripped = array(); + $first = TRUE; + foreach ($lines as $line) { + // If the line is too long, just pretend the entire line is one big word + // This prevents resource exhaustion problems + if ( $first ) { + $first = FALSE; + } + else { + $words[] = "\n"; + $stripped[] = "\n"; + } + if ( drupal_strlen( $line ) > $this->MAX_LINE_LENGTH() ) { + $words[] = $line; + $stripped[] = $line; + } + else { + if (preg_match_all('/ ( [^\S\n]+ | [0-9_A-Za-z\x80-\xff]+ | . ) (?: (?!< \n) [^\S\n])? /xs', $line, $m)) { + $words = array_merge($words, $m[0]); + $stripped = array_merge($stripped, $m[1]); + } + } + } + return array($words, $stripped); + } + + function orig() { + $orig = new _HWLDF_WordAccumulator; + + foreach ($this->edits as $edit) { + if ($edit->type == 'copy') { + $orig->addWords($edit->orig); + } + elseif ($edit->orig) { + $orig->addWords($edit->orig, 'mark'); + } + } + $lines = $orig->getLines(); + return $lines; + } + + function closing() { + $closing = new _HWLDF_WordAccumulator; + + foreach ($this->edits as $edit) { + if ($edit->type == 'copy') { + $closing->addWords($edit->closing); + } + elseif ($edit->closing) { + $closing->addWords($edit->closing, 'mark'); + } + } + $lines = $closing->getLines(); + return $lines; + } +} + +/** + * Diff formatter which uses Drupal theme functions. + * @private + * @subpackage DifferenceEngine + */ +class DrupalDiffFormatter extends DiffFormatter { + + var $rows; + var $line_stats = array( + 'counter' => array('x' => 0, 'y' => 0), + 'offset' => array('x' => 0, 'y' => 0), + ); + + function DrupalDiffFormatter() { + $this->leading_context_lines = \Drupal::config('diff.settings')->get('diff_context_lines_leading'); + $this->trailing_context_lines = \Drupal::config('diff.settings')->get('diff_context_lines_trailing'); + } + + function _start_diff() { + $this->rows = array(); + } + + function _end_diff() { + return $this->rows; + } + + function _block_header($xbeg, $xlen, $ybeg, $ylen) { + return array( + array( + 'data' => _theme('diff_header_line', array('lineno' => $xbeg + $this->line_stats['offset']['x'])), + 'colspan' => 2, + ), + array( + 'data' => _theme('diff_header_line', array('lineno' => $ybeg + $this->line_stats['offset']['y'])), + 'colspan' => 2, + ) + ); + } + + function _start_block($header) { + if ($this->show_header) { + $this->rows[] = $header; + } + } + + function _end_block() { + } + + function _lines($lines, $prefix=' ', $color='white') { + } + + /** + * Note: you should HTML-escape parameter before calling this. + */ + function addedLine($line) { + return array( + array( + 'data' => '+', + 'class' => 'diff-marker', + ), + array( + 'data' => _theme('diff_content_line', array('line' => $line)), + 'class' => 'diff-context diff-addedline', + ) + ); + } + + /** + * Note: you should HTML-escape parameter before calling this. + */ + function deletedLine($line) { + return array( + array( + 'data' => '-', + 'class' => 'diff-marker', + ), + array( + 'data' => _theme('diff_content_line', array('line' => $line)), + 'class' => 'diff-context diff-deletedline', + ) + ); + } + + /** + * Note: you should HTML-escape parameter before calling this. + */ + function contextLine($line) { + return array( + ' ', + array( + 'data' => _theme('diff_content_line', array('line' => $line)), + 'class' => 'diff-context', + ) + ); + } + + function emptyLine() { + return array( + ' ', + _theme('diff_empty_line', array('line' => ' ')), + ); + } + + function _added($lines) { + foreach ($lines as $line) { + $this->rows[] = array_merge($this->emptyLine(), $this->addedLine(check_plain($line))); + } + } + + function _deleted($lines) { + foreach ($lines as $line) { + $this->rows[] = array_merge($this->deletedLine(check_plain($line)), $this->emptyLine()); + } + } + + function _context($lines) { + foreach ($lines as $line) { + $this->rows[] = array_merge($this->contextLine(check_plain($line)), $this->contextLine(check_plain($line))); + } + } + + function _changed($orig, $closing) { + $diff = new WordLevelDiff($orig, $closing); + $del = $diff->orig(); + $add = $diff->closing(); + + // Notice that WordLevelDiff returns HTML-escaped output. + // Hence, we will be calling addedLine/deletedLine without HTML-escaping. + + while ($line = array_shift($del)) { + $aline = array_shift( $add ); + $this->rows[] = array_merge($this->deletedLine($line), isset($aline) ? $this->addedLine($aline) : $this->emptyLine()); + } + foreach ($add as $line) { // If any leftovers + $this->rows[] = array_merge($this->emptyLine(), $this->addedLine($line)); + } + } +} + +/** + * Drupal inline Diff formatter. + * @private + * @subpackage DifferenceEngine + */ +class DrupalDiffInline { + var $a; + var $b; + + /** + * Constructor. + */ + function __construct($a, $b) { + $this->a = $a; + $this->b = $b; + } + + /** + * Render differences inline using HTML markup. + */ + function render() { + $a = preg_split('/(<[^>]+?>| )/', $this->a, -1, PREG_SPLIT_DELIM_CAPTURE); + $b = preg_split('/(<[^>]+?>| )/', $this->b, -1, PREG_SPLIT_DELIM_CAPTURE); + $diff = new Diff($a, $b); + $diff->edits = $this->process_edits($diff->edits); + + // Assemble highlighted output + $output = ''; + foreach ($diff->edits as $chunk) { + switch ($chunk->type) { + case 'copy': + $output .= implode('', $chunk->closing); + break; + case 'delete': + foreach ($chunk->orig as $i => $piece) { + if (strpos($piece, '<') === 0 && drupal_substr($piece, drupal_strlen($piece) - 1) === '>') { + $output .= $piece; + } + else { + $output .= _theme('diff_inline_chunk', array('text' => $piece, 'type' => $chunk->type)); + } + } + break; + default: + $chunk->closing = $this->process_chunk($chunk->closing); + foreach ($chunk->closing as $i => $piece) { + if ($piece === ' ' || (strpos($piece, '<') === 0 && drupal_substr($piece, drupal_strlen($piece) - 1) === '>' && drupal_strtolower(drupal_substr($piece, 1, 3)) != 'img')) { + $output .= $piece; + } + else { + $output .= _theme('diff_inline_chunk', array('text' => $piece, 'type' => $chunk->type)); + } + } + break; + } + } + return $output; + } + + /** + * Merge chunk segments between tag delimiters. + */ + function process_chunk($chunk) { + $processed = array(); + $j = 0; + foreach ($chunk as $i => $piece) { + $next = isset($chunk[$i+1]) ? $chunk[$i+1] : NULL; + if (!isset($processed[$j])) { + $processed[$j] = ''; + } + if (strpos($piece, '<') === 0 && drupal_substr($piece, drupal_strlen($piece) - 1) === '>') { + $processed[$j] = $piece; + $j++; + } + elseif (isset($next) && strpos($next, '<') === 0 && drupal_substr($next, drupal_strlen($next) - 1) === '>') { + $processed[$j] .= $piece; + $j++; + } + else { + $processed[$j] .= $piece; + } + } + return $processed; + } + + /** + * Merge copy and equivalent edits into intelligible chunks. + */ + function process_edits($edits) { + $processed = array(); + $current = array_shift($edits); + + // Make two passes -- first merge space delimiter copies back into their originals. + while ($chunk = array_shift($edits)) { + if ($chunk->type == 'copy' && $chunk->orig === array(' ')) { + $current->orig = array_merge((array) $current->orig, (array) $chunk->orig); + $current->closing = array_merge((array) $current->closing, (array) $chunk->closing); + } + else { + $processed[] = $current; + $current = $chunk; + } + } + $processed[] = $current; + + // Initial setup + $edits = $processed; + $processed = array(); + $current = array_shift($edits); + + // Second, merge equivalent chunks into each other. + while ($chunk = array_shift($edits)) { + if ($current->type == $chunk->type) { + $current->orig = array_merge((array) $current->orig, (array) $chunk->orig); + $current->closing = array_merge((array) $current->closing, (array) $chunk->closing); + } + else { + $processed[] = $current; + $current = $chunk; + } + } + $processed[] = $current; + + return $processed; + } +} diff --git a/src/_DiffOp.php b/src/_DiffOp.php new file mode 100644 index 0000000..f0c0d51 --- /dev/null +++ b/src/_DiffOp.php @@ -0,0 +1,1355 @@ + + * You may copy this code freely under the conditions of the GPL. + */ + +define('USE_ASSERTS', FALSE); + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp { + var $type; + var $orig; + var $closing; + + function reverse() { + trigger_error('pure virtual', E_USER_ERROR); + } + + function norig() { + return $this->orig ? sizeof($this->orig) : 0; + } + + function nclosing() { + return $this->closing ? sizeof($this->closing) : 0; + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Copy extends _DiffOp { + var $type = 'copy'; + + function _DiffOp_Copy($orig, $closing = FALSE) { + if (!is_array($closing)) { + $closing = $orig; + } + $this->orig = $orig; + $this->closing = $closing; + } + + function reverse() { + return new _DiffOp_Copy($this->closing, $this->orig); + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Delete extends _DiffOp { + var $type = 'delete'; + + function _DiffOp_Delete($lines) { + $this->orig = $lines; + $this->closing = FALSE; + } + + function reverse() { + return new _DiffOp_Add($this->orig); + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Add extends _DiffOp { + var $type = 'add'; + + function _DiffOp_Add($lines) { + $this->closing = $lines; + $this->orig = FALSE; + } + + function reverse() { + return new _DiffOp_Delete($this->closing); + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Change extends _DiffOp { + var $type = 'change'; + + function _DiffOp_Change($orig, $closing) { + $this->orig = $orig; + $this->closing = $closing; + } + + function reverse() { + return new _DiffOp_Change($this->closing, $this->orig); + } +} + + +/** + * Class used internally by Diff to actually compute the diffs. + * + * The algorithm used here is mostly lifted from the perl module + * Algorithm::Diff (version 1.06) by Ned Konz, which is available at: + * http://www.perl.com/CPAN/authors/id/N/NE/NEDKONZ/Algorithm-Diff-1.06.zip + * + * More ideas are taken from: + * http://www.ics.uci.edu/~eppstein/161/960229.html + * + * Some ideas are (and a bit of code) are from from analyze.c, from GNU + * diffutils-2.7, which can be found at: + * ftp://gnudist.gnu.org/pub/gnu/diffutils/diffutils-2.7.tar.gz + * + * closingly, some ideas (subdivision by NCHUNKS > 2, and some optimizations) + * are my own. + * + * Line length limits for robustness added by Tim Starling, 2005-08-31 + * + * @author Geoffrey T. Dairiki, Tim Starling + * @private + * @subpackage DifferenceEngine + */ +class _DiffEngine { + function MAX_XREF_LENGTH() { + return 10000; + } + + function diff($from_lines, $to_lines) { + + $n_from = sizeof($from_lines); + $n_to = sizeof($to_lines); + + $this->xchanged = $this->ychanged = array(); + $this->xv = $this->yv = array(); + $this->xind = $this->yind = array(); + unset($this->seq); + unset($this->in_seq); + unset($this->lcs); + + // Skip leading common lines. + for ($skip = 0; $skip < $n_from && $skip < $n_to; $skip++) { + if ($from_lines[$skip] !== $to_lines[$skip]) { + break; + } + $this->xchanged[$skip] = $this->ychanged[$skip] = FALSE; + } + // Skip trailing common lines. + $xi = $n_from; + $yi = $n_to; + for ($endskip = 0; --$xi > $skip && --$yi > $skip; $endskip++) { + if ($from_lines[$xi] !== $to_lines[$yi]) { + break; + } + $this->xchanged[$xi] = $this->ychanged[$yi] = FALSE; + } + + // Ignore lines which do not exist in both files. + for ($xi = $skip; $xi < $n_from - $endskip; $xi++) { + $xhash[$this->_line_hash($from_lines[$xi])] = 1; + } + + for ($yi = $skip; $yi < $n_to - $endskip; $yi++) { + $line = $to_lines[$yi]; + if ($this->ychanged[$yi] = empty($xhash[$this->_line_hash($line)])) { + continue; + } + $yhash[$this->_line_hash($line)] = 1; + $this->yv[] = $line; + $this->yind[] = $yi; + } + for ($xi = $skip; $xi < $n_from - $endskip; $xi++) { + $line = $from_lines[$xi]; + if ($this->xchanged[$xi] = empty($yhash[$this->_line_hash($line)])) { + continue; + } + $this->xv[] = $line; + $this->xind[] = $xi; + } + + // Find the LCS. + $this->_compareseq(0, sizeof($this->xv), 0, sizeof($this->yv)); + + // Merge edits when possible + $this->_shift_boundaries($from_lines, $this->xchanged, $this->ychanged); + $this->_shift_boundaries($to_lines, $this->ychanged, $this->xchanged); + + // Compute the edit operations. + $edits = array(); + $xi = $yi = 0; + while ($xi < $n_from || $yi < $n_to) { + USE_ASSERTS && assert($yi < $n_to || $this->xchanged[$xi]); + USE_ASSERTS && assert($xi < $n_from || $this->ychanged[$yi]); + + // Skip matching "snake". + $copy = array(); + while ( $xi < $n_from && $yi < $n_to && !$this->xchanged[$xi] && !$this->ychanged[$yi]) { + $copy[] = $from_lines[$xi++]; + ++$yi; + } + if ($copy) { + $edits[] = new _DiffOp_Copy($copy); + } + // Find deletes & adds. + $delete = array(); + while ($xi < $n_from && $this->xchanged[$xi]) { + $_fl = $from_lines[$xi++]; + if (strlen($_fl)) { + $delete[] = $_fl; + } + } + $add = array(); + while ($yi < $n_to && $this->ychanged[$yi]) { + $_tl = $to_lines[$yi++]; + if (strlen($_tl)) { + $add[] = $_tl; + } + } + if ($delete && $add) { + $edits[] = new _DiffOp_Change($delete, $add); + } + elseif ($delete) { + $edits[] = new _DiffOp_Delete($delete); + } + elseif ($add) { + $edits[] = new _DiffOp_Add($add); + } + } + return $edits; + } + + /** + * Returns the whole line if it's small enough, or the MD5 hash otherwise. + */ + function _line_hash($line) { + if (drupal_strlen($line) > $this->MAX_XREF_LENGTH()) { + return md5($line); + } + else { + return $line; + } + } + + + /** + * Divide the Largest Common Subsequence (LCS) of the sequences + * [XOFF, XLIM) and [YOFF, YLIM) into NCHUNKS approximately equally + * sized segments. + * + * Returns (LCS, PTS). LCS is the length of the LCS. PTS is an + * array of NCHUNKS+1 (X, Y) indexes giving the diving points between + * sub sequences. The first sub-sequence is contained in [X0, X1), + * [Y0, Y1), the second in [X1, X2), [Y1, Y2) and so on. Note + * that (X0, Y0) == (XOFF, YOFF) and + * (X[NCHUNKS], Y[NCHUNKS]) == (XLIM, YLIM). + * + * This function assumes that the first lines of the specified portions + * of the two files do not match, and likewise that the last lines do not + * match. The caller must trim matching lines from the beginning and end + * of the portions it is going to specify. + */ + function _diag($xoff, $xlim, $yoff, $ylim, $nchunks) { + $flip = FALSE; + + if ($xlim - $xoff > $ylim - $yoff) { + // Things seems faster (I'm not sure I understand why) + // when the shortest sequence in X. + $flip = TRUE; + list($xoff, $xlim, $yoff, $ylim) = array($yoff, $ylim, $xoff, $xlim); + } + + if ($flip) { + for ($i = $ylim - 1; $i >= $yoff; $i--) { + $ymatches[$this->xv[$i]][] = $i; + } + } + else { + for ($i = $ylim - 1; $i >= $yoff; $i--) { + $ymatches[$this->yv[$i]][] = $i; + } + } + $this->lcs = 0; + $this->seq[0]= $yoff - 1; + $this->in_seq = array(); + $ymids[0] = array(); + + $numer = $xlim - $xoff + $nchunks - 1; + $x = $xoff; + for ($chunk = 0; $chunk < $nchunks; $chunk++) { + if ($chunk > 0) { + for ($i = 0; $i <= $this->lcs; $i++) { + $ymids[$i][$chunk-1] = $this->seq[$i]; + } + } + + $x1 = $xoff + (int)(($numer + ($xlim-$xoff)*$chunk) / $nchunks); + for ( ; $x < $x1; $x++) { + $line = $flip ? $this->yv[$x] : $this->xv[$x]; + if (empty($ymatches[$line])) { + continue; + } + $matches = $ymatches[$line]; + reset($matches); + while (list ($junk, $y) = each($matches)) { + if (empty($this->in_seq[$y])) { + $k = $this->_lcs_pos($y); + USE_ASSERTS && assert($k > 0); + $ymids[$k] = $ymids[$k-1]; + break; + } + } + while (list ($junk, $y) = each($matches)) { + if ($y > $this->seq[$k-1]) { + USE_ASSERTS && assert($y < $this->seq[$k]); + // Optimization: this is a common case: + // next match is just replacing previous match. + $this->in_seq[$this->seq[$k]] = FALSE; + $this->seq[$k] = $y; + $this->in_seq[$y] = 1; + } + elseif (empty($this->in_seq[$y])) { + $k = $this->_lcs_pos($y); + USE_ASSERTS && assert($k > 0); + $ymids[$k] = $ymids[$k-1]; + } + } + } + } + + $seps[] = $flip ? array($yoff, $xoff) : array($xoff, $yoff); + $ymid = $ymids[$this->lcs]; + for ($n = 0; $n < $nchunks - 1; $n++) { + $x1 = $xoff + (int)(($numer + ($xlim - $xoff) * $n) / $nchunks); + $y1 = $ymid[$n] + 1; + $seps[] = $flip ? array($y1, $x1) : array($x1, $y1); + } + $seps[] = $flip ? array($ylim, $xlim) : array($xlim, $ylim); + + return array($this->lcs, $seps); + } + + function _lcs_pos($ypos) { + + $end = $this->lcs; + if ($end == 0 || $ypos > $this->seq[$end]) { + $this->seq[++$this->lcs] = $ypos; + $this->in_seq[$ypos] = 1; + return $this->lcs; + } + + $beg = 1; + while ($beg < $end) { + $mid = (int)(($beg + $end) / 2); + if ($ypos > $this->seq[$mid]) { + $beg = $mid + 1; + } + else { + $end = $mid; + } + } + + USE_ASSERTS && assert($ypos != $this->seq[$end]); + + $this->in_seq[$this->seq[$end]] = FALSE; + $this->seq[$end] = $ypos; + $this->in_seq[$ypos] = 1; + return $end; + } + + /** + * Find LCS of two sequences. + * + * The results are recorded in the vectors $this->{x,y}changed[], by + * storing a 1 in the element for each line that is an insertion + * or deletion (ie. is not in the LCS). + * + * The subsequence of file 0 is [XOFF, XLIM) and likewise for file 1. + * + * Note that XLIM, YLIM are exclusive bounds. + * All line numbers are origin-0 and discarded lines are not counted. + */ + function _compareseq($xoff, $xlim, $yoff, $ylim) { + + // Slide down the bottom initial diagonal. + while ($xoff < $xlim && $yoff < $ylim && $this->xv[$xoff] == $this->yv[$yoff]) { + ++$xoff; + ++$yoff; + } + + // Slide up the top initial diagonal. + while ($xlim > $xoff && $ylim > $yoff && $this->xv[$xlim - 1] == $this->yv[$ylim - 1]) { + --$xlim; + --$ylim; + } + + if ($xoff == $xlim || $yoff == $ylim) { + $lcs = 0; + } + else { + // This is ad hoc but seems to work well. + //$nchunks = sqrt(min($xlim - $xoff, $ylim - $yoff) / 2.5); + //$nchunks = max(2, min(8, (int)$nchunks)); + $nchunks = min(7, $xlim - $xoff, $ylim - $yoff) + 1; + list($lcs, $seps) + = $this->_diag($xoff, $xlim, $yoff, $ylim, $nchunks); + } + + if ($lcs == 0) { + // X and Y sequences have no common subsequence: + // mark all changed. + while ($yoff < $ylim) { + $this->ychanged[$this->yind[$yoff++]] = 1; + } + while ($xoff < $xlim) { + $this->xchanged[$this->xind[$xoff++]] = 1; + } + } + else { + // Use the partitions to split this problem into subproblems. + reset($seps); + $pt1 = $seps[0]; + while ($pt2 = next($seps)) { + $this->_compareseq ($pt1[0], $pt2[0], $pt1[1], $pt2[1]); + $pt1 = $pt2; + } + } + } + + /** + * Adjust inserts/deletes of identical lines to join changes + * as much as possible. + * + * We do something when a run of changed lines include a + * line at one end and has an excluded, identical line at the other. + * We are free to choose which identical line is included. + * `compareseq' usually chooses the one at the beginning, + * but usually it is cleaner to consider the following identical line + * to be the "change". + * + * This is extracted verbatim from analyze.c (GNU diffutils-2.7). + */ + function _shift_boundaries($lines, &$changed, $other_changed) { + $i = 0; + $j = 0; + + USE_ASSERTS && assert('sizeof($lines) == sizeof($changed)'); + $len = sizeof($lines); + $other_len = sizeof($other_changed); + + while (1) { + /* + * Scan forwards to find beginning of another run of changes. + * Also keep track of the corresponding point in the other file. + * + * Throughout this code, $i and $j are adjusted together so that + * the first $i elements of $changed and the first $j elements + * of $other_changed both contain the same number of zeros + * (unchanged lines). + * Furthermore, $j is always kept so that $j == $other_len or + * $other_changed[$j] == FALSE. + */ + while ($j < $other_len && $other_changed[$j]) { + $j++; + } + while ($i < $len && ! $changed[$i]) { + USE_ASSERTS && assert('$j < $other_len && ! $other_changed[$j]'); + $i++; + $j++; + while ($j < $other_len && $other_changed[$j]) { + $j++; + } + } + + if ($i == $len) { + break; + } + $start = $i; + + // Find the end of this run of changes. + while (++$i < $len && $changed[$i]) { + continue; + } + + do { + /* + * Record the length of this run of changes, so that + * we can later determine whether the run has grown. + */ + $runlength = $i - $start; + + /* + * Move the changed region back, so long as the + * previous unchanged line matches the last changed one. + * This merges with previous changed regions. + */ + while ($start > 0 && $lines[$start - 1] == $lines[$i - 1]) { + $changed[--$start] = 1; + $changed[--$i] = FALSE; + while ($start > 0 && $changed[$start - 1]) { + $start--; + } + USE_ASSERTS && assert('$j > 0'); + while ($other_changed[--$j]) { + continue; + } + USE_ASSERTS && assert('$j >= 0 && !$other_changed[$j]'); + } + + /* + * Set CORRESPONDING to the end of the changed run, at the last + * point where it corresponds to a changed run in the other file. + * CORRESPONDING == LEN means no such point has been found. + */ + $corresponding = $j < $other_len ? $i : $len; + + /* + * Move the changed region forward, so long as the + * first changed line matches the following unchanged one. + * This merges with following changed regions. + * Do this second, so that if there are no merges, + * the changed region is moved forward as far as possible. + */ + while ($i < $len && $lines[$start] == $lines[$i]) { + $changed[$start++] = FALSE; + $changed[$i++] = 1; + while ($i < $len && $changed[$i]) { + $i++; + } + USE_ASSERTS && assert('$j < $other_len && ! $other_changed[$j]'); + $j++; + if ($j < $other_len && $other_changed[$j]) { + $corresponding = $i; + while ($j < $other_len && $other_changed[$j]) { + $j++; + } + } + } + } while ($runlength != $i - $start); + + /* + * If possible, move the fully-merged run of changes + * back to a corresponding run in the other file. + */ + while ($corresponding < $i) { + $changed[--$start] = 1; + $changed[--$i] = 0; + USE_ASSERTS && assert('$j > 0'); + while ($other_changed[--$j]) { + continue; + } + USE_ASSERTS && assert('$j >= 0 && !$other_changed[$j]'); + } + } + } +} + +/** + * Class representing a 'diff' between two sequences of strings. + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class Diff { + var $edits; + + /** + * Constructor. + * Computes diff between sequences of strings. + * + * @param $from_lines array An array of strings. + * (Typically these are lines from a file.) + * @param $to_lines array An array of strings. + */ + function Diff($from_lines, $to_lines) { + $eng = new _DiffEngine; + $this->edits = $eng->diff($from_lines, $to_lines); + //$this->_check($from_lines, $to_lines); + } + + /** + * Compute reversed Diff. + * + * SYNOPSIS: + * + * $diff = new Diff($lines1, $lines2); + * $rev = $diff->reverse(); + * @return object A Diff object representing the inverse of the + * original diff. + */ + function reverse() { + $rev = $this; + $rev->edits = array(); + foreach ($this->edits as $edit) { + $rev->edits[] = $edit->reverse(); + } + return $rev; + } + + /** + * Check for empty diff. + * + * @return bool True iff two sequences were identical. + */ + function isEmpty() { + foreach ($this->edits as $edit) { + if ($edit->type != 'copy') { + return FALSE; + } + } + return TRUE; + } + + /** + * Compute the length of the Longest Common Subsequence (LCS). + * + * This is mostly for diagnostic purposed. + * + * @return int The length of the LCS. + */ + function lcs() { + $lcs = 0; + foreach ($this->edits as $edit) { + if ($edit->type == 'copy') { + $lcs += sizeof($edit->orig); + } + } + return $lcs; + } + + /** + * Get the original set of lines. + * + * This reconstructs the $from_lines parameter passed to the + * constructor. + * + * @return array The original sequence of strings. + */ + function orig() { + $lines = array(); + + foreach ($this->edits as $edit) { + if ($edit->orig) { + array_splice($lines, sizeof($lines), 0, $edit->orig); + } + } + return $lines; + } + + /** + * Get the closing set of lines. + * + * This reconstructs the $to_lines parameter passed to the + * constructor. + * + * @return array The sequence of strings. + */ + function closing() { + $lines = array(); + + foreach ($this->edits as $edit) { + if ($edit->closing) { + array_splice($lines, sizeof($lines), 0, $edit->closing); + } + } + return $lines; + } + + /** + * Check a Diff for validity. + * + * This is here only for debugging purposes. + */ + function _check($from_lines, $to_lines) { + if (serialize($from_lines) != serialize($this->orig())) { + trigger_error("Reconstructed original doesn't match", E_USER_ERROR); + } + if (serialize($to_lines) != serialize($this->closing())) { + trigger_error("Reconstructed closing doesn't match", E_USER_ERROR); + } + + $rev = $this->reverse(); + if (serialize($to_lines) != serialize($rev->orig())) { + trigger_error("Reversed original doesn't match", E_USER_ERROR); + } + if (serialize($from_lines) != serialize($rev->closing())) { + trigger_error("Reversed closing doesn't match", E_USER_ERROR); + } + + + $prevtype = 'none'; + foreach ($this->edits as $edit) { + if ( $prevtype == $edit->type ) { + trigger_error("Edit sequence is non-optimal", E_USER_ERROR); + } + $prevtype = $edit->type; + } + + $lcs = $this->lcs(); + trigger_error('Diff okay: LCS = ' . $lcs, E_USER_NOTICE); + } +} + +/** + * FIXME: bad name. + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class MappedDiff extends Diff { + /** + * Constructor. + * + * Computes diff between sequences of strings. + * + * This can be used to compute things like + * case-insensitve diffs, or diffs which ignore + * changes in white-space. + * + * @param $from_lines array An array of strings. + * (Typically these are lines from a file.) + * + * @param $to_lines array An array of strings. + * + * @param $mapped_from_lines array This array should + * have the same size number of elements as $from_lines. + * The elements in $mapped_from_lines and + * $mapped_to_lines are what is actually compared + * when computing the diff. + * + * @param $mapped_to_lines array This array should + * have the same number of elements as $to_lines. + */ + function MappedDiff($from_lines, $to_lines, $mapped_from_lines, $mapped_to_lines) { + + assert(sizeof($from_lines) == sizeof($mapped_from_lines)); + assert(sizeof($to_lines) == sizeof($mapped_to_lines)); + + $this->Diff($mapped_from_lines, $mapped_to_lines); + + $xi = $yi = 0; + for ($i = 0; $i < sizeof($this->edits); $i++) { + $orig = &$this->edits[$i]->orig; + if (is_array($orig)) { + $orig = array_slice($from_lines, $xi, sizeof($orig)); + $xi += sizeof($orig); + } + + $closing = &$this->edits[$i]->closing; + if (is_array($closing)) { + $closing = array_slice($to_lines, $yi, sizeof($closing)); + $yi += sizeof($closing); + } + } + } +} + +/** + * A class to format Diffs + * + * This class formats the diff in classic diff format. + * It is intended that this class be customized via inheritance, + * to obtain fancier outputs. + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class DiffFormatter { + /** + * Should a block header be shown? + */ + var $show_header = TRUE; + + /** + * Number of leading context "lines" to preserve. + * + * This should be left at zero for this class, but subclasses + * may want to set this to other values. + */ + var $leading_context_lines = 0; + + /** + * Number of trailing context "lines" to preserve. + * + * This should be left at zero for this class, but subclasses + * may want to set this to other values. + */ + var $trailing_context_lines = 0; + + /** + * Format a diff. + * + * @param $diff object A Diff object. + * @return string The formatted output. + */ + function format($diff) { + $xi = $yi = 1; + $block = FALSE; + $context = array(); + + $nlead = $this->leading_context_lines; + $ntrail = $this->trailing_context_lines; + + $this->_start_diff(); + + foreach ($diff->edits as $edit) { + if ($edit->type == 'copy') { + if (is_array($block)) { + if (sizeof($edit->orig) <= $nlead + $ntrail) { + $block[] = $edit; + } + else { + if ($ntrail) { + $context = array_slice($edit->orig, 0, $ntrail); + $block[] = new _DiffOp_Copy($context); + } + $this->_block($x0, $ntrail + $xi - $x0, $y0, $ntrail + $yi - $y0, $block); + $block = FALSE; + } + } + $context = $edit->orig; + } + else { + if (! is_array($block)) { + $context = array_slice($context, sizeof($context) - $nlead); + $x0 = $xi - sizeof($context); + $y0 = $yi - sizeof($context); + $block = array(); + if ($context) { + $block[] = new _DiffOp_Copy($context); + } + } + $block[] = $edit; + } + + if ($edit->orig) { + $xi += sizeof($edit->orig); + } + if ($edit->closing) { + $yi += sizeof($edit->closing); + } + } + + if (is_array($block)) { + $this->_block($x0, $xi - $x0, $y0, $yi - $y0, $block); + } + $end = $this->_end_diff(); + + if (!empty($xi)) { + $this->line_stats['counter']['x'] += $xi; + } + if (!empty($yi)) { + $this->line_stats['counter']['y'] += $yi; + } + + return $end; + } + + function _block($xbeg, $xlen, $ybeg, $ylen, &$edits) { + $this->_start_block($this->_block_header($xbeg, $xlen, $ybeg, $ylen)); + foreach ($edits as $edit) { + if ($edit->type == 'copy') { + $this->_context($edit->orig); + } + elseif ($edit->type == 'add') { + $this->_added($edit->closing); + } + elseif ($edit->type == 'delete') { + $this->_deleted($edit->orig); + } + elseif ($edit->type == 'change') { + $this->_changed($edit->orig, $edit->closing); + } + else { + trigger_error('Unknown edit type', E_USER_ERROR); + } + } + $this->_end_block(); + } + + function _start_diff() { + ob_start(); + } + + function _end_diff() { + $val = ob_get_contents(); + ob_end_clean(); + return $val; + } + + function _block_header($xbeg, $xlen, $ybeg, $ylen) { + if ($xlen > 1) { + $xbeg .= "," . ($xbeg + $xlen - 1); + } + if ($ylen > 1) { + $ybeg .= "," . ($ybeg + $ylen - 1); + } + + return $xbeg . ($xlen ? ($ylen ? 'c' : 'd') : 'a') . $ybeg; + } + + function _start_block($header) { + if ($this->show_header) { + echo $header . "\n"; + } + } + + function _end_block() { + } + + function _lines($lines, $prefix = ' ') { + foreach ($lines as $line) { + echo "$prefix $line\n"; + } + } + + function _context($lines) { + $this->_lines($lines); + } + + function _added($lines) { + $this->_lines($lines, '>'); + } + function _deleted($lines) { + $this->_lines($lines, '<'); + } + + function _changed($orig, $closing) { + $this->_deleted($orig); + echo "---\n"; + $this->_added($closing); + } +} + + +/** + * Additions by Axel Boldt follow, partly taken from diff.php, phpwiki-1.3.3 + * + */ + +define('NBSP', ' '); // iso-8859-x non-breaking space. + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _HWLDF_WordAccumulator { + function _HWLDF_WordAccumulator() { + $this->_lines = array(); + $this->_line = ''; + $this->_group = ''; + $this->_tag = ''; + } + + function _flushGroup($new_tag) { + if ($this->_group !== '') { + if ($this->_tag == 'mark') { + $this->_line .= '' . check_plain($this->_group) . ''; + } + else { + $this->_line .= check_plain($this->_group); + } + } + $this->_group = ''; + $this->_tag = $new_tag; + } + + function _flushLine($new_tag) { + $this->_flushGroup($new_tag); + if ($this->_line != '') { + array_push($this->_lines, $this->_line); + } + else { + // make empty lines visible by inserting an NBSP + array_push($this->_lines, NBSP); + } + $this->_line = ''; + } + + function addWords($words, $tag = '') { + if ($tag != $this->_tag) { + $this->_flushGroup($tag); + } + foreach ($words as $word) { + // new-line should only come as first char of word. + if ($word == '') { + continue; + } + if ($word[0] == "\n") { + $this->_flushLine($tag); + $word = drupal_substr($word, 1); + } + assert(!strstr($word, "\n")); + $this->_group .= $word; + } + } + + function getLines() { + $this->_flushLine('~done'); + return $this->_lines; + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class WordLevelDiff extends MappedDiff { + function MAX_LINE_LENGTH() { + return 10000; + } + + function WordLevelDiff($orig_lines, $closing_lines) { + list($orig_words, $orig_stripped) = $this->_split($orig_lines); + list($closing_words, $closing_stripped) = $this->_split($closing_lines); + + $this->MappedDiff($orig_words, $closing_words, $orig_stripped, $closing_stripped); + } + + function _split($lines) { + $words = array(); + $stripped = array(); + $first = TRUE; + foreach ($lines as $line) { + // If the line is too long, just pretend the entire line is one big word + // This prevents resource exhaustion problems + if ( $first ) { + $first = FALSE; + } + else { + $words[] = "\n"; + $stripped[] = "\n"; + } + if ( drupal_strlen( $line ) > $this->MAX_LINE_LENGTH() ) { + $words[] = $line; + $stripped[] = $line; + } + else { + if (preg_match_all('/ ( [^\S\n]+ | [0-9_A-Za-z\x80-\xff]+ | . ) (?: (?!< \n) [^\S\n])? /xs', $line, $m)) { + $words = array_merge($words, $m[0]); + $stripped = array_merge($stripped, $m[1]); + } + } + } + return array($words, $stripped); + } + + function orig() { + $orig = new _HWLDF_WordAccumulator; + + foreach ($this->edits as $edit) { + if ($edit->type == 'copy') { + $orig->addWords($edit->orig); + } + elseif ($edit->orig) { + $orig->addWords($edit->orig, 'mark'); + } + } + $lines = $orig->getLines(); + return $lines; + } + + function closing() { + $closing = new _HWLDF_WordAccumulator; + + foreach ($this->edits as $edit) { + if ($edit->type == 'copy') { + $closing->addWords($edit->closing); + } + elseif ($edit->closing) { + $closing->addWords($edit->closing, 'mark'); + } + } + $lines = $closing->getLines(); + return $lines; + } +} + +/** + * Diff formatter which uses Drupal theme functions. + * @private + * @subpackage DifferenceEngine + */ +class DrupalDiffFormatter extends DiffFormatter { + + var $rows; + var $line_stats = array( + 'counter' => array('x' => 0, 'y' => 0), + 'offset' => array('x' => 0, 'y' => 0), + ); + + function DrupalDiffFormatter() { + $this->leading_context_lines = \Drupal::config('diff.settings')->get('diff_context_lines_leading'); + $this->trailing_context_lines = \Drupal::config('diff.settings')->get('diff_context_lines_trailing'); + } + + function _start_diff() { + $this->rows = array(); + } + + function _end_diff() { + return $this->rows; + } + + function _block_header($xbeg, $xlen, $ybeg, $ylen) { + return array( + array( + 'data' => _theme('diff_header_line', array('lineno' => $xbeg + $this->line_stats['offset']['x'])), + 'colspan' => 2, + ), + array( + 'data' => _theme('diff_header_line', array('lineno' => $ybeg + $this->line_stats['offset']['y'])), + 'colspan' => 2, + ) + ); + } + + function _start_block($header) { + if ($this->show_header) { + $this->rows[] = $header; + } + } + + function _end_block() { + } + + function _lines($lines, $prefix=' ', $color='white') { + } + + /** + * Note: you should HTML-escape parameter before calling this. + */ + function addedLine($line) { + return array( + array( + 'data' => '+', + 'class' => 'diff-marker', + ), + array( + 'data' => _theme('diff_content_line', array('line' => $line)), + 'class' => 'diff-context diff-addedline', + ) + ); + } + + /** + * Note: you should HTML-escape parameter before calling this. + */ + function deletedLine($line) { + return array( + array( + 'data' => '-', + 'class' => 'diff-marker', + ), + array( + 'data' => _theme('diff_content_line', array('line' => $line)), + 'class' => 'diff-context diff-deletedline', + ) + ); + } + + /** + * Note: you should HTML-escape parameter before calling this. + */ + function contextLine($line) { + return array( + ' ', + array( + 'data' => _theme('diff_content_line', array('line' => $line)), + 'class' => 'diff-context', + ) + ); + } + + function emptyLine() { + return array( + ' ', + _theme('diff_empty_line', array('line' => ' ')), + ); + } + + function _added($lines) { + foreach ($lines as $line) { + $this->rows[] = array_merge($this->emptyLine(), $this->addedLine(check_plain($line))); + } + } + + function _deleted($lines) { + foreach ($lines as $line) { + $this->rows[] = array_merge($this->deletedLine(check_plain($line)), $this->emptyLine()); + } + } + + function _context($lines) { + foreach ($lines as $line) { + $this->rows[] = array_merge($this->contextLine(check_plain($line)), $this->contextLine(check_plain($line))); + } + } + + function _changed($orig, $closing) { + $diff = new WordLevelDiff($orig, $closing); + $del = $diff->orig(); + $add = $diff->closing(); + + // Notice that WordLevelDiff returns HTML-escaped output. + // Hence, we will be calling addedLine/deletedLine without HTML-escaping. + + while ($line = array_shift($del)) { + $aline = array_shift( $add ); + $this->rows[] = array_merge($this->deletedLine($line), isset($aline) ? $this->addedLine($aline) : $this->emptyLine()); + } + foreach ($add as $line) { // If any leftovers + $this->rows[] = array_merge($this->emptyLine(), $this->addedLine($line)); + } + } +} + +/** + * Drupal inline Diff formatter. + * @private + * @subpackage DifferenceEngine + */ +class DrupalDiffInline { + var $a; + var $b; + + /** + * Constructor. + */ + function __construct($a, $b) { + $this->a = $a; + $this->b = $b; + } + + /** + * Render differences inline using HTML markup. + */ + function render() { + $a = preg_split('/(<[^>]+?>| )/', $this->a, -1, PREG_SPLIT_DELIM_CAPTURE); + $b = preg_split('/(<[^>]+?>| )/', $this->b, -1, PREG_SPLIT_DELIM_CAPTURE); + $diff = new Diff($a, $b); + $diff->edits = $this->process_edits($diff->edits); + + // Assemble highlighted output + $output = ''; + foreach ($diff->edits as $chunk) { + switch ($chunk->type) { + case 'copy': + $output .= implode('', $chunk->closing); + break; + case 'delete': + foreach ($chunk->orig as $i => $piece) { + if (strpos($piece, '<') === 0 && drupal_substr($piece, drupal_strlen($piece) - 1) === '>') { + $output .= $piece; + } + else { + $output .= _theme('diff_inline_chunk', array('text' => $piece, 'type' => $chunk->type)); + } + } + break; + default: + $chunk->closing = $this->process_chunk($chunk->closing); + foreach ($chunk->closing as $i => $piece) { + if ($piece === ' ' || (strpos($piece, '<') === 0 && drupal_substr($piece, drupal_strlen($piece) - 1) === '>' && drupal_strtolower(drupal_substr($piece, 1, 3)) != 'img')) { + $output .= $piece; + } + else { + $output .= _theme('diff_inline_chunk', array('text' => $piece, 'type' => $chunk->type)); + } + } + break; + } + } + return $output; + } + + /** + * Merge chunk segments between tag delimiters. + */ + function process_chunk($chunk) { + $processed = array(); + $j = 0; + foreach ($chunk as $i => $piece) { + $next = isset($chunk[$i+1]) ? $chunk[$i+1] : NULL; + if (!isset($processed[$j])) { + $processed[$j] = ''; + } + if (strpos($piece, '<') === 0 && drupal_substr($piece, drupal_strlen($piece) - 1) === '>') { + $processed[$j] = $piece; + $j++; + } + elseif (isset($next) && strpos($next, '<') === 0 && drupal_substr($next, drupal_strlen($next) - 1) === '>') { + $processed[$j] .= $piece; + $j++; + } + else { + $processed[$j] .= $piece; + } + } + return $processed; + } + + /** + * Merge copy and equivalent edits into intelligible chunks. + */ + function process_edits($edits) { + $processed = array(); + $current = array_shift($edits); + + // Make two passes -- first merge space delimiter copies back into their originals. + while ($chunk = array_shift($edits)) { + if ($chunk->type == 'copy' && $chunk->orig === array(' ')) { + $current->orig = array_merge((array) $current->orig, (array) $chunk->orig); + $current->closing = array_merge((array) $current->closing, (array) $chunk->closing); + } + else { + $processed[] = $current; + $current = $chunk; + } + } + $processed[] = $current; + + // Initial setup + $edits = $processed; + $processed = array(); + $current = array_shift($edits); + + // Second, merge equivalent chunks into each other. + while ($chunk = array_shift($edits)) { + if ($current->type == $chunk->type) { + $current->orig = array_merge((array) $current->orig, (array) $chunk->orig); + $current->closing = array_merge((array) $current->closing, (array) $chunk->closing); + } + else { + $processed[] = $current; + $current = $chunk; + } + } + $processed[] = $current; + + return $processed; + } +} diff --git a/src/_DiffOp_Add.php b/src/_DiffOp_Add.php new file mode 100644 index 0000000..f0c0d51 --- /dev/null +++ b/src/_DiffOp_Add.php @@ -0,0 +1,1355 @@ + + * You may copy this code freely under the conditions of the GPL. + */ + +define('USE_ASSERTS', FALSE); + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp { + var $type; + var $orig; + var $closing; + + function reverse() { + trigger_error('pure virtual', E_USER_ERROR); + } + + function norig() { + return $this->orig ? sizeof($this->orig) : 0; + } + + function nclosing() { + return $this->closing ? sizeof($this->closing) : 0; + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Copy extends _DiffOp { + var $type = 'copy'; + + function _DiffOp_Copy($orig, $closing = FALSE) { + if (!is_array($closing)) { + $closing = $orig; + } + $this->orig = $orig; + $this->closing = $closing; + } + + function reverse() { + return new _DiffOp_Copy($this->closing, $this->orig); + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Delete extends _DiffOp { + var $type = 'delete'; + + function _DiffOp_Delete($lines) { + $this->orig = $lines; + $this->closing = FALSE; + } + + function reverse() { + return new _DiffOp_Add($this->orig); + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Add extends _DiffOp { + var $type = 'add'; + + function _DiffOp_Add($lines) { + $this->closing = $lines; + $this->orig = FALSE; + } + + function reverse() { + return new _DiffOp_Delete($this->closing); + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Change extends _DiffOp { + var $type = 'change'; + + function _DiffOp_Change($orig, $closing) { + $this->orig = $orig; + $this->closing = $closing; + } + + function reverse() { + return new _DiffOp_Change($this->closing, $this->orig); + } +} + + +/** + * Class used internally by Diff to actually compute the diffs. + * + * The algorithm used here is mostly lifted from the perl module + * Algorithm::Diff (version 1.06) by Ned Konz, which is available at: + * http://www.perl.com/CPAN/authors/id/N/NE/NEDKONZ/Algorithm-Diff-1.06.zip + * + * More ideas are taken from: + * http://www.ics.uci.edu/~eppstein/161/960229.html + * + * Some ideas are (and a bit of code) are from from analyze.c, from GNU + * diffutils-2.7, which can be found at: + * ftp://gnudist.gnu.org/pub/gnu/diffutils/diffutils-2.7.tar.gz + * + * closingly, some ideas (subdivision by NCHUNKS > 2, and some optimizations) + * are my own. + * + * Line length limits for robustness added by Tim Starling, 2005-08-31 + * + * @author Geoffrey T. Dairiki, Tim Starling + * @private + * @subpackage DifferenceEngine + */ +class _DiffEngine { + function MAX_XREF_LENGTH() { + return 10000; + } + + function diff($from_lines, $to_lines) { + + $n_from = sizeof($from_lines); + $n_to = sizeof($to_lines); + + $this->xchanged = $this->ychanged = array(); + $this->xv = $this->yv = array(); + $this->xind = $this->yind = array(); + unset($this->seq); + unset($this->in_seq); + unset($this->lcs); + + // Skip leading common lines. + for ($skip = 0; $skip < $n_from && $skip < $n_to; $skip++) { + if ($from_lines[$skip] !== $to_lines[$skip]) { + break; + } + $this->xchanged[$skip] = $this->ychanged[$skip] = FALSE; + } + // Skip trailing common lines. + $xi = $n_from; + $yi = $n_to; + for ($endskip = 0; --$xi > $skip && --$yi > $skip; $endskip++) { + if ($from_lines[$xi] !== $to_lines[$yi]) { + break; + } + $this->xchanged[$xi] = $this->ychanged[$yi] = FALSE; + } + + // Ignore lines which do not exist in both files. + for ($xi = $skip; $xi < $n_from - $endskip; $xi++) { + $xhash[$this->_line_hash($from_lines[$xi])] = 1; + } + + for ($yi = $skip; $yi < $n_to - $endskip; $yi++) { + $line = $to_lines[$yi]; + if ($this->ychanged[$yi] = empty($xhash[$this->_line_hash($line)])) { + continue; + } + $yhash[$this->_line_hash($line)] = 1; + $this->yv[] = $line; + $this->yind[] = $yi; + } + for ($xi = $skip; $xi < $n_from - $endskip; $xi++) { + $line = $from_lines[$xi]; + if ($this->xchanged[$xi] = empty($yhash[$this->_line_hash($line)])) { + continue; + } + $this->xv[] = $line; + $this->xind[] = $xi; + } + + // Find the LCS. + $this->_compareseq(0, sizeof($this->xv), 0, sizeof($this->yv)); + + // Merge edits when possible + $this->_shift_boundaries($from_lines, $this->xchanged, $this->ychanged); + $this->_shift_boundaries($to_lines, $this->ychanged, $this->xchanged); + + // Compute the edit operations. + $edits = array(); + $xi = $yi = 0; + while ($xi < $n_from || $yi < $n_to) { + USE_ASSERTS && assert($yi < $n_to || $this->xchanged[$xi]); + USE_ASSERTS && assert($xi < $n_from || $this->ychanged[$yi]); + + // Skip matching "snake". + $copy = array(); + while ( $xi < $n_from && $yi < $n_to && !$this->xchanged[$xi] && !$this->ychanged[$yi]) { + $copy[] = $from_lines[$xi++]; + ++$yi; + } + if ($copy) { + $edits[] = new _DiffOp_Copy($copy); + } + // Find deletes & adds. + $delete = array(); + while ($xi < $n_from && $this->xchanged[$xi]) { + $_fl = $from_lines[$xi++]; + if (strlen($_fl)) { + $delete[] = $_fl; + } + } + $add = array(); + while ($yi < $n_to && $this->ychanged[$yi]) { + $_tl = $to_lines[$yi++]; + if (strlen($_tl)) { + $add[] = $_tl; + } + } + if ($delete && $add) { + $edits[] = new _DiffOp_Change($delete, $add); + } + elseif ($delete) { + $edits[] = new _DiffOp_Delete($delete); + } + elseif ($add) { + $edits[] = new _DiffOp_Add($add); + } + } + return $edits; + } + + /** + * Returns the whole line if it's small enough, or the MD5 hash otherwise. + */ + function _line_hash($line) { + if (drupal_strlen($line) > $this->MAX_XREF_LENGTH()) { + return md5($line); + } + else { + return $line; + } + } + + + /** + * Divide the Largest Common Subsequence (LCS) of the sequences + * [XOFF, XLIM) and [YOFF, YLIM) into NCHUNKS approximately equally + * sized segments. + * + * Returns (LCS, PTS). LCS is the length of the LCS. PTS is an + * array of NCHUNKS+1 (X, Y) indexes giving the diving points between + * sub sequences. The first sub-sequence is contained in [X0, X1), + * [Y0, Y1), the second in [X1, X2), [Y1, Y2) and so on. Note + * that (X0, Y0) == (XOFF, YOFF) and + * (X[NCHUNKS], Y[NCHUNKS]) == (XLIM, YLIM). + * + * This function assumes that the first lines of the specified portions + * of the two files do not match, and likewise that the last lines do not + * match. The caller must trim matching lines from the beginning and end + * of the portions it is going to specify. + */ + function _diag($xoff, $xlim, $yoff, $ylim, $nchunks) { + $flip = FALSE; + + if ($xlim - $xoff > $ylim - $yoff) { + // Things seems faster (I'm not sure I understand why) + // when the shortest sequence in X. + $flip = TRUE; + list($xoff, $xlim, $yoff, $ylim) = array($yoff, $ylim, $xoff, $xlim); + } + + if ($flip) { + for ($i = $ylim - 1; $i >= $yoff; $i--) { + $ymatches[$this->xv[$i]][] = $i; + } + } + else { + for ($i = $ylim - 1; $i >= $yoff; $i--) { + $ymatches[$this->yv[$i]][] = $i; + } + } + $this->lcs = 0; + $this->seq[0]= $yoff - 1; + $this->in_seq = array(); + $ymids[0] = array(); + + $numer = $xlim - $xoff + $nchunks - 1; + $x = $xoff; + for ($chunk = 0; $chunk < $nchunks; $chunk++) { + if ($chunk > 0) { + for ($i = 0; $i <= $this->lcs; $i++) { + $ymids[$i][$chunk-1] = $this->seq[$i]; + } + } + + $x1 = $xoff + (int)(($numer + ($xlim-$xoff)*$chunk) / $nchunks); + for ( ; $x < $x1; $x++) { + $line = $flip ? $this->yv[$x] : $this->xv[$x]; + if (empty($ymatches[$line])) { + continue; + } + $matches = $ymatches[$line]; + reset($matches); + while (list ($junk, $y) = each($matches)) { + if (empty($this->in_seq[$y])) { + $k = $this->_lcs_pos($y); + USE_ASSERTS && assert($k > 0); + $ymids[$k] = $ymids[$k-1]; + break; + } + } + while (list ($junk, $y) = each($matches)) { + if ($y > $this->seq[$k-1]) { + USE_ASSERTS && assert($y < $this->seq[$k]); + // Optimization: this is a common case: + // next match is just replacing previous match. + $this->in_seq[$this->seq[$k]] = FALSE; + $this->seq[$k] = $y; + $this->in_seq[$y] = 1; + } + elseif (empty($this->in_seq[$y])) { + $k = $this->_lcs_pos($y); + USE_ASSERTS && assert($k > 0); + $ymids[$k] = $ymids[$k-1]; + } + } + } + } + + $seps[] = $flip ? array($yoff, $xoff) : array($xoff, $yoff); + $ymid = $ymids[$this->lcs]; + for ($n = 0; $n < $nchunks - 1; $n++) { + $x1 = $xoff + (int)(($numer + ($xlim - $xoff) * $n) / $nchunks); + $y1 = $ymid[$n] + 1; + $seps[] = $flip ? array($y1, $x1) : array($x1, $y1); + } + $seps[] = $flip ? array($ylim, $xlim) : array($xlim, $ylim); + + return array($this->lcs, $seps); + } + + function _lcs_pos($ypos) { + + $end = $this->lcs; + if ($end == 0 || $ypos > $this->seq[$end]) { + $this->seq[++$this->lcs] = $ypos; + $this->in_seq[$ypos] = 1; + return $this->lcs; + } + + $beg = 1; + while ($beg < $end) { + $mid = (int)(($beg + $end) / 2); + if ($ypos > $this->seq[$mid]) { + $beg = $mid + 1; + } + else { + $end = $mid; + } + } + + USE_ASSERTS && assert($ypos != $this->seq[$end]); + + $this->in_seq[$this->seq[$end]] = FALSE; + $this->seq[$end] = $ypos; + $this->in_seq[$ypos] = 1; + return $end; + } + + /** + * Find LCS of two sequences. + * + * The results are recorded in the vectors $this->{x,y}changed[], by + * storing a 1 in the element for each line that is an insertion + * or deletion (ie. is not in the LCS). + * + * The subsequence of file 0 is [XOFF, XLIM) and likewise for file 1. + * + * Note that XLIM, YLIM are exclusive bounds. + * All line numbers are origin-0 and discarded lines are not counted. + */ + function _compareseq($xoff, $xlim, $yoff, $ylim) { + + // Slide down the bottom initial diagonal. + while ($xoff < $xlim && $yoff < $ylim && $this->xv[$xoff] == $this->yv[$yoff]) { + ++$xoff; + ++$yoff; + } + + // Slide up the top initial diagonal. + while ($xlim > $xoff && $ylim > $yoff && $this->xv[$xlim - 1] == $this->yv[$ylim - 1]) { + --$xlim; + --$ylim; + } + + if ($xoff == $xlim || $yoff == $ylim) { + $lcs = 0; + } + else { + // This is ad hoc but seems to work well. + //$nchunks = sqrt(min($xlim - $xoff, $ylim - $yoff) / 2.5); + //$nchunks = max(2, min(8, (int)$nchunks)); + $nchunks = min(7, $xlim - $xoff, $ylim - $yoff) + 1; + list($lcs, $seps) + = $this->_diag($xoff, $xlim, $yoff, $ylim, $nchunks); + } + + if ($lcs == 0) { + // X and Y sequences have no common subsequence: + // mark all changed. + while ($yoff < $ylim) { + $this->ychanged[$this->yind[$yoff++]] = 1; + } + while ($xoff < $xlim) { + $this->xchanged[$this->xind[$xoff++]] = 1; + } + } + else { + // Use the partitions to split this problem into subproblems. + reset($seps); + $pt1 = $seps[0]; + while ($pt2 = next($seps)) { + $this->_compareseq ($pt1[0], $pt2[0], $pt1[1], $pt2[1]); + $pt1 = $pt2; + } + } + } + + /** + * Adjust inserts/deletes of identical lines to join changes + * as much as possible. + * + * We do something when a run of changed lines include a + * line at one end and has an excluded, identical line at the other. + * We are free to choose which identical line is included. + * `compareseq' usually chooses the one at the beginning, + * but usually it is cleaner to consider the following identical line + * to be the "change". + * + * This is extracted verbatim from analyze.c (GNU diffutils-2.7). + */ + function _shift_boundaries($lines, &$changed, $other_changed) { + $i = 0; + $j = 0; + + USE_ASSERTS && assert('sizeof($lines) == sizeof($changed)'); + $len = sizeof($lines); + $other_len = sizeof($other_changed); + + while (1) { + /* + * Scan forwards to find beginning of another run of changes. + * Also keep track of the corresponding point in the other file. + * + * Throughout this code, $i and $j are adjusted together so that + * the first $i elements of $changed and the first $j elements + * of $other_changed both contain the same number of zeros + * (unchanged lines). + * Furthermore, $j is always kept so that $j == $other_len or + * $other_changed[$j] == FALSE. + */ + while ($j < $other_len && $other_changed[$j]) { + $j++; + } + while ($i < $len && ! $changed[$i]) { + USE_ASSERTS && assert('$j < $other_len && ! $other_changed[$j]'); + $i++; + $j++; + while ($j < $other_len && $other_changed[$j]) { + $j++; + } + } + + if ($i == $len) { + break; + } + $start = $i; + + // Find the end of this run of changes. + while (++$i < $len && $changed[$i]) { + continue; + } + + do { + /* + * Record the length of this run of changes, so that + * we can later determine whether the run has grown. + */ + $runlength = $i - $start; + + /* + * Move the changed region back, so long as the + * previous unchanged line matches the last changed one. + * This merges with previous changed regions. + */ + while ($start > 0 && $lines[$start - 1] == $lines[$i - 1]) { + $changed[--$start] = 1; + $changed[--$i] = FALSE; + while ($start > 0 && $changed[$start - 1]) { + $start--; + } + USE_ASSERTS && assert('$j > 0'); + while ($other_changed[--$j]) { + continue; + } + USE_ASSERTS && assert('$j >= 0 && !$other_changed[$j]'); + } + + /* + * Set CORRESPONDING to the end of the changed run, at the last + * point where it corresponds to a changed run in the other file. + * CORRESPONDING == LEN means no such point has been found. + */ + $corresponding = $j < $other_len ? $i : $len; + + /* + * Move the changed region forward, so long as the + * first changed line matches the following unchanged one. + * This merges with following changed regions. + * Do this second, so that if there are no merges, + * the changed region is moved forward as far as possible. + */ + while ($i < $len && $lines[$start] == $lines[$i]) { + $changed[$start++] = FALSE; + $changed[$i++] = 1; + while ($i < $len && $changed[$i]) { + $i++; + } + USE_ASSERTS && assert('$j < $other_len && ! $other_changed[$j]'); + $j++; + if ($j < $other_len && $other_changed[$j]) { + $corresponding = $i; + while ($j < $other_len && $other_changed[$j]) { + $j++; + } + } + } + } while ($runlength != $i - $start); + + /* + * If possible, move the fully-merged run of changes + * back to a corresponding run in the other file. + */ + while ($corresponding < $i) { + $changed[--$start] = 1; + $changed[--$i] = 0; + USE_ASSERTS && assert('$j > 0'); + while ($other_changed[--$j]) { + continue; + } + USE_ASSERTS && assert('$j >= 0 && !$other_changed[$j]'); + } + } + } +} + +/** + * Class representing a 'diff' between two sequences of strings. + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class Diff { + var $edits; + + /** + * Constructor. + * Computes diff between sequences of strings. + * + * @param $from_lines array An array of strings. + * (Typically these are lines from a file.) + * @param $to_lines array An array of strings. + */ + function Diff($from_lines, $to_lines) { + $eng = new _DiffEngine; + $this->edits = $eng->diff($from_lines, $to_lines); + //$this->_check($from_lines, $to_lines); + } + + /** + * Compute reversed Diff. + * + * SYNOPSIS: + * + * $diff = new Diff($lines1, $lines2); + * $rev = $diff->reverse(); + * @return object A Diff object representing the inverse of the + * original diff. + */ + function reverse() { + $rev = $this; + $rev->edits = array(); + foreach ($this->edits as $edit) { + $rev->edits[] = $edit->reverse(); + } + return $rev; + } + + /** + * Check for empty diff. + * + * @return bool True iff two sequences were identical. + */ + function isEmpty() { + foreach ($this->edits as $edit) { + if ($edit->type != 'copy') { + return FALSE; + } + } + return TRUE; + } + + /** + * Compute the length of the Longest Common Subsequence (LCS). + * + * This is mostly for diagnostic purposed. + * + * @return int The length of the LCS. + */ + function lcs() { + $lcs = 0; + foreach ($this->edits as $edit) { + if ($edit->type == 'copy') { + $lcs += sizeof($edit->orig); + } + } + return $lcs; + } + + /** + * Get the original set of lines. + * + * This reconstructs the $from_lines parameter passed to the + * constructor. + * + * @return array The original sequence of strings. + */ + function orig() { + $lines = array(); + + foreach ($this->edits as $edit) { + if ($edit->orig) { + array_splice($lines, sizeof($lines), 0, $edit->orig); + } + } + return $lines; + } + + /** + * Get the closing set of lines. + * + * This reconstructs the $to_lines parameter passed to the + * constructor. + * + * @return array The sequence of strings. + */ + function closing() { + $lines = array(); + + foreach ($this->edits as $edit) { + if ($edit->closing) { + array_splice($lines, sizeof($lines), 0, $edit->closing); + } + } + return $lines; + } + + /** + * Check a Diff for validity. + * + * This is here only for debugging purposes. + */ + function _check($from_lines, $to_lines) { + if (serialize($from_lines) != serialize($this->orig())) { + trigger_error("Reconstructed original doesn't match", E_USER_ERROR); + } + if (serialize($to_lines) != serialize($this->closing())) { + trigger_error("Reconstructed closing doesn't match", E_USER_ERROR); + } + + $rev = $this->reverse(); + if (serialize($to_lines) != serialize($rev->orig())) { + trigger_error("Reversed original doesn't match", E_USER_ERROR); + } + if (serialize($from_lines) != serialize($rev->closing())) { + trigger_error("Reversed closing doesn't match", E_USER_ERROR); + } + + + $prevtype = 'none'; + foreach ($this->edits as $edit) { + if ( $prevtype == $edit->type ) { + trigger_error("Edit sequence is non-optimal", E_USER_ERROR); + } + $prevtype = $edit->type; + } + + $lcs = $this->lcs(); + trigger_error('Diff okay: LCS = ' . $lcs, E_USER_NOTICE); + } +} + +/** + * FIXME: bad name. + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class MappedDiff extends Diff { + /** + * Constructor. + * + * Computes diff between sequences of strings. + * + * This can be used to compute things like + * case-insensitve diffs, or diffs which ignore + * changes in white-space. + * + * @param $from_lines array An array of strings. + * (Typically these are lines from a file.) + * + * @param $to_lines array An array of strings. + * + * @param $mapped_from_lines array This array should + * have the same size number of elements as $from_lines. + * The elements in $mapped_from_lines and + * $mapped_to_lines are what is actually compared + * when computing the diff. + * + * @param $mapped_to_lines array This array should + * have the same number of elements as $to_lines. + */ + function MappedDiff($from_lines, $to_lines, $mapped_from_lines, $mapped_to_lines) { + + assert(sizeof($from_lines) == sizeof($mapped_from_lines)); + assert(sizeof($to_lines) == sizeof($mapped_to_lines)); + + $this->Diff($mapped_from_lines, $mapped_to_lines); + + $xi = $yi = 0; + for ($i = 0; $i < sizeof($this->edits); $i++) { + $orig = &$this->edits[$i]->orig; + if (is_array($orig)) { + $orig = array_slice($from_lines, $xi, sizeof($orig)); + $xi += sizeof($orig); + } + + $closing = &$this->edits[$i]->closing; + if (is_array($closing)) { + $closing = array_slice($to_lines, $yi, sizeof($closing)); + $yi += sizeof($closing); + } + } + } +} + +/** + * A class to format Diffs + * + * This class formats the diff in classic diff format. + * It is intended that this class be customized via inheritance, + * to obtain fancier outputs. + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class DiffFormatter { + /** + * Should a block header be shown? + */ + var $show_header = TRUE; + + /** + * Number of leading context "lines" to preserve. + * + * This should be left at zero for this class, but subclasses + * may want to set this to other values. + */ + var $leading_context_lines = 0; + + /** + * Number of trailing context "lines" to preserve. + * + * This should be left at zero for this class, but subclasses + * may want to set this to other values. + */ + var $trailing_context_lines = 0; + + /** + * Format a diff. + * + * @param $diff object A Diff object. + * @return string The formatted output. + */ + function format($diff) { + $xi = $yi = 1; + $block = FALSE; + $context = array(); + + $nlead = $this->leading_context_lines; + $ntrail = $this->trailing_context_lines; + + $this->_start_diff(); + + foreach ($diff->edits as $edit) { + if ($edit->type == 'copy') { + if (is_array($block)) { + if (sizeof($edit->orig) <= $nlead + $ntrail) { + $block[] = $edit; + } + else { + if ($ntrail) { + $context = array_slice($edit->orig, 0, $ntrail); + $block[] = new _DiffOp_Copy($context); + } + $this->_block($x0, $ntrail + $xi - $x0, $y0, $ntrail + $yi - $y0, $block); + $block = FALSE; + } + } + $context = $edit->orig; + } + else { + if (! is_array($block)) { + $context = array_slice($context, sizeof($context) - $nlead); + $x0 = $xi - sizeof($context); + $y0 = $yi - sizeof($context); + $block = array(); + if ($context) { + $block[] = new _DiffOp_Copy($context); + } + } + $block[] = $edit; + } + + if ($edit->orig) { + $xi += sizeof($edit->orig); + } + if ($edit->closing) { + $yi += sizeof($edit->closing); + } + } + + if (is_array($block)) { + $this->_block($x0, $xi - $x0, $y0, $yi - $y0, $block); + } + $end = $this->_end_diff(); + + if (!empty($xi)) { + $this->line_stats['counter']['x'] += $xi; + } + if (!empty($yi)) { + $this->line_stats['counter']['y'] += $yi; + } + + return $end; + } + + function _block($xbeg, $xlen, $ybeg, $ylen, &$edits) { + $this->_start_block($this->_block_header($xbeg, $xlen, $ybeg, $ylen)); + foreach ($edits as $edit) { + if ($edit->type == 'copy') { + $this->_context($edit->orig); + } + elseif ($edit->type == 'add') { + $this->_added($edit->closing); + } + elseif ($edit->type == 'delete') { + $this->_deleted($edit->orig); + } + elseif ($edit->type == 'change') { + $this->_changed($edit->orig, $edit->closing); + } + else { + trigger_error('Unknown edit type', E_USER_ERROR); + } + } + $this->_end_block(); + } + + function _start_diff() { + ob_start(); + } + + function _end_diff() { + $val = ob_get_contents(); + ob_end_clean(); + return $val; + } + + function _block_header($xbeg, $xlen, $ybeg, $ylen) { + if ($xlen > 1) { + $xbeg .= "," . ($xbeg + $xlen - 1); + } + if ($ylen > 1) { + $ybeg .= "," . ($ybeg + $ylen - 1); + } + + return $xbeg . ($xlen ? ($ylen ? 'c' : 'd') : 'a') . $ybeg; + } + + function _start_block($header) { + if ($this->show_header) { + echo $header . "\n"; + } + } + + function _end_block() { + } + + function _lines($lines, $prefix = ' ') { + foreach ($lines as $line) { + echo "$prefix $line\n"; + } + } + + function _context($lines) { + $this->_lines($lines); + } + + function _added($lines) { + $this->_lines($lines, '>'); + } + function _deleted($lines) { + $this->_lines($lines, '<'); + } + + function _changed($orig, $closing) { + $this->_deleted($orig); + echo "---\n"; + $this->_added($closing); + } +} + + +/** + * Additions by Axel Boldt follow, partly taken from diff.php, phpwiki-1.3.3 + * + */ + +define('NBSP', ' '); // iso-8859-x non-breaking space. + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _HWLDF_WordAccumulator { + function _HWLDF_WordAccumulator() { + $this->_lines = array(); + $this->_line = ''; + $this->_group = ''; + $this->_tag = ''; + } + + function _flushGroup($new_tag) { + if ($this->_group !== '') { + if ($this->_tag == 'mark') { + $this->_line .= '' . check_plain($this->_group) . ''; + } + else { + $this->_line .= check_plain($this->_group); + } + } + $this->_group = ''; + $this->_tag = $new_tag; + } + + function _flushLine($new_tag) { + $this->_flushGroup($new_tag); + if ($this->_line != '') { + array_push($this->_lines, $this->_line); + } + else { + // make empty lines visible by inserting an NBSP + array_push($this->_lines, NBSP); + } + $this->_line = ''; + } + + function addWords($words, $tag = '') { + if ($tag != $this->_tag) { + $this->_flushGroup($tag); + } + foreach ($words as $word) { + // new-line should only come as first char of word. + if ($word == '') { + continue; + } + if ($word[0] == "\n") { + $this->_flushLine($tag); + $word = drupal_substr($word, 1); + } + assert(!strstr($word, "\n")); + $this->_group .= $word; + } + } + + function getLines() { + $this->_flushLine('~done'); + return $this->_lines; + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class WordLevelDiff extends MappedDiff { + function MAX_LINE_LENGTH() { + return 10000; + } + + function WordLevelDiff($orig_lines, $closing_lines) { + list($orig_words, $orig_stripped) = $this->_split($orig_lines); + list($closing_words, $closing_stripped) = $this->_split($closing_lines); + + $this->MappedDiff($orig_words, $closing_words, $orig_stripped, $closing_stripped); + } + + function _split($lines) { + $words = array(); + $stripped = array(); + $first = TRUE; + foreach ($lines as $line) { + // If the line is too long, just pretend the entire line is one big word + // This prevents resource exhaustion problems + if ( $first ) { + $first = FALSE; + } + else { + $words[] = "\n"; + $stripped[] = "\n"; + } + if ( drupal_strlen( $line ) > $this->MAX_LINE_LENGTH() ) { + $words[] = $line; + $stripped[] = $line; + } + else { + if (preg_match_all('/ ( [^\S\n]+ | [0-9_A-Za-z\x80-\xff]+ | . ) (?: (?!< \n) [^\S\n])? /xs', $line, $m)) { + $words = array_merge($words, $m[0]); + $stripped = array_merge($stripped, $m[1]); + } + } + } + return array($words, $stripped); + } + + function orig() { + $orig = new _HWLDF_WordAccumulator; + + foreach ($this->edits as $edit) { + if ($edit->type == 'copy') { + $orig->addWords($edit->orig); + } + elseif ($edit->orig) { + $orig->addWords($edit->orig, 'mark'); + } + } + $lines = $orig->getLines(); + return $lines; + } + + function closing() { + $closing = new _HWLDF_WordAccumulator; + + foreach ($this->edits as $edit) { + if ($edit->type == 'copy') { + $closing->addWords($edit->closing); + } + elseif ($edit->closing) { + $closing->addWords($edit->closing, 'mark'); + } + } + $lines = $closing->getLines(); + return $lines; + } +} + +/** + * Diff formatter which uses Drupal theme functions. + * @private + * @subpackage DifferenceEngine + */ +class DrupalDiffFormatter extends DiffFormatter { + + var $rows; + var $line_stats = array( + 'counter' => array('x' => 0, 'y' => 0), + 'offset' => array('x' => 0, 'y' => 0), + ); + + function DrupalDiffFormatter() { + $this->leading_context_lines = \Drupal::config('diff.settings')->get('diff_context_lines_leading'); + $this->trailing_context_lines = \Drupal::config('diff.settings')->get('diff_context_lines_trailing'); + } + + function _start_diff() { + $this->rows = array(); + } + + function _end_diff() { + return $this->rows; + } + + function _block_header($xbeg, $xlen, $ybeg, $ylen) { + return array( + array( + 'data' => _theme('diff_header_line', array('lineno' => $xbeg + $this->line_stats['offset']['x'])), + 'colspan' => 2, + ), + array( + 'data' => _theme('diff_header_line', array('lineno' => $ybeg + $this->line_stats['offset']['y'])), + 'colspan' => 2, + ) + ); + } + + function _start_block($header) { + if ($this->show_header) { + $this->rows[] = $header; + } + } + + function _end_block() { + } + + function _lines($lines, $prefix=' ', $color='white') { + } + + /** + * Note: you should HTML-escape parameter before calling this. + */ + function addedLine($line) { + return array( + array( + 'data' => '+', + 'class' => 'diff-marker', + ), + array( + 'data' => _theme('diff_content_line', array('line' => $line)), + 'class' => 'diff-context diff-addedline', + ) + ); + } + + /** + * Note: you should HTML-escape parameter before calling this. + */ + function deletedLine($line) { + return array( + array( + 'data' => '-', + 'class' => 'diff-marker', + ), + array( + 'data' => _theme('diff_content_line', array('line' => $line)), + 'class' => 'diff-context diff-deletedline', + ) + ); + } + + /** + * Note: you should HTML-escape parameter before calling this. + */ + function contextLine($line) { + return array( + ' ', + array( + 'data' => _theme('diff_content_line', array('line' => $line)), + 'class' => 'diff-context', + ) + ); + } + + function emptyLine() { + return array( + ' ', + _theme('diff_empty_line', array('line' => ' ')), + ); + } + + function _added($lines) { + foreach ($lines as $line) { + $this->rows[] = array_merge($this->emptyLine(), $this->addedLine(check_plain($line))); + } + } + + function _deleted($lines) { + foreach ($lines as $line) { + $this->rows[] = array_merge($this->deletedLine(check_plain($line)), $this->emptyLine()); + } + } + + function _context($lines) { + foreach ($lines as $line) { + $this->rows[] = array_merge($this->contextLine(check_plain($line)), $this->contextLine(check_plain($line))); + } + } + + function _changed($orig, $closing) { + $diff = new WordLevelDiff($orig, $closing); + $del = $diff->orig(); + $add = $diff->closing(); + + // Notice that WordLevelDiff returns HTML-escaped output. + // Hence, we will be calling addedLine/deletedLine without HTML-escaping. + + while ($line = array_shift($del)) { + $aline = array_shift( $add ); + $this->rows[] = array_merge($this->deletedLine($line), isset($aline) ? $this->addedLine($aline) : $this->emptyLine()); + } + foreach ($add as $line) { // If any leftovers + $this->rows[] = array_merge($this->emptyLine(), $this->addedLine($line)); + } + } +} + +/** + * Drupal inline Diff formatter. + * @private + * @subpackage DifferenceEngine + */ +class DrupalDiffInline { + var $a; + var $b; + + /** + * Constructor. + */ + function __construct($a, $b) { + $this->a = $a; + $this->b = $b; + } + + /** + * Render differences inline using HTML markup. + */ + function render() { + $a = preg_split('/(<[^>]+?>| )/', $this->a, -1, PREG_SPLIT_DELIM_CAPTURE); + $b = preg_split('/(<[^>]+?>| )/', $this->b, -1, PREG_SPLIT_DELIM_CAPTURE); + $diff = new Diff($a, $b); + $diff->edits = $this->process_edits($diff->edits); + + // Assemble highlighted output + $output = ''; + foreach ($diff->edits as $chunk) { + switch ($chunk->type) { + case 'copy': + $output .= implode('', $chunk->closing); + break; + case 'delete': + foreach ($chunk->orig as $i => $piece) { + if (strpos($piece, '<') === 0 && drupal_substr($piece, drupal_strlen($piece) - 1) === '>') { + $output .= $piece; + } + else { + $output .= _theme('diff_inline_chunk', array('text' => $piece, 'type' => $chunk->type)); + } + } + break; + default: + $chunk->closing = $this->process_chunk($chunk->closing); + foreach ($chunk->closing as $i => $piece) { + if ($piece === ' ' || (strpos($piece, '<') === 0 && drupal_substr($piece, drupal_strlen($piece) - 1) === '>' && drupal_strtolower(drupal_substr($piece, 1, 3)) != 'img')) { + $output .= $piece; + } + else { + $output .= _theme('diff_inline_chunk', array('text' => $piece, 'type' => $chunk->type)); + } + } + break; + } + } + return $output; + } + + /** + * Merge chunk segments between tag delimiters. + */ + function process_chunk($chunk) { + $processed = array(); + $j = 0; + foreach ($chunk as $i => $piece) { + $next = isset($chunk[$i+1]) ? $chunk[$i+1] : NULL; + if (!isset($processed[$j])) { + $processed[$j] = ''; + } + if (strpos($piece, '<') === 0 && drupal_substr($piece, drupal_strlen($piece) - 1) === '>') { + $processed[$j] = $piece; + $j++; + } + elseif (isset($next) && strpos($next, '<') === 0 && drupal_substr($next, drupal_strlen($next) - 1) === '>') { + $processed[$j] .= $piece; + $j++; + } + else { + $processed[$j] .= $piece; + } + } + return $processed; + } + + /** + * Merge copy and equivalent edits into intelligible chunks. + */ + function process_edits($edits) { + $processed = array(); + $current = array_shift($edits); + + // Make two passes -- first merge space delimiter copies back into their originals. + while ($chunk = array_shift($edits)) { + if ($chunk->type == 'copy' && $chunk->orig === array(' ')) { + $current->orig = array_merge((array) $current->orig, (array) $chunk->orig); + $current->closing = array_merge((array) $current->closing, (array) $chunk->closing); + } + else { + $processed[] = $current; + $current = $chunk; + } + } + $processed[] = $current; + + // Initial setup + $edits = $processed; + $processed = array(); + $current = array_shift($edits); + + // Second, merge equivalent chunks into each other. + while ($chunk = array_shift($edits)) { + if ($current->type == $chunk->type) { + $current->orig = array_merge((array) $current->orig, (array) $chunk->orig); + $current->closing = array_merge((array) $current->closing, (array) $chunk->closing); + } + else { + $processed[] = $current; + $current = $chunk; + } + } + $processed[] = $current; + + return $processed; + } +} diff --git a/src/_DiffOp_Change.php b/src/_DiffOp_Change.php new file mode 100644 index 0000000..f0c0d51 --- /dev/null +++ b/src/_DiffOp_Change.php @@ -0,0 +1,1355 @@ + + * You may copy this code freely under the conditions of the GPL. + */ + +define('USE_ASSERTS', FALSE); + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp { + var $type; + var $orig; + var $closing; + + function reverse() { + trigger_error('pure virtual', E_USER_ERROR); + } + + function norig() { + return $this->orig ? sizeof($this->orig) : 0; + } + + function nclosing() { + return $this->closing ? sizeof($this->closing) : 0; + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Copy extends _DiffOp { + var $type = 'copy'; + + function _DiffOp_Copy($orig, $closing = FALSE) { + if (!is_array($closing)) { + $closing = $orig; + } + $this->orig = $orig; + $this->closing = $closing; + } + + function reverse() { + return new _DiffOp_Copy($this->closing, $this->orig); + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Delete extends _DiffOp { + var $type = 'delete'; + + function _DiffOp_Delete($lines) { + $this->orig = $lines; + $this->closing = FALSE; + } + + function reverse() { + return new _DiffOp_Add($this->orig); + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Add extends _DiffOp { + var $type = 'add'; + + function _DiffOp_Add($lines) { + $this->closing = $lines; + $this->orig = FALSE; + } + + function reverse() { + return new _DiffOp_Delete($this->closing); + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Change extends _DiffOp { + var $type = 'change'; + + function _DiffOp_Change($orig, $closing) { + $this->orig = $orig; + $this->closing = $closing; + } + + function reverse() { + return new _DiffOp_Change($this->closing, $this->orig); + } +} + + +/** + * Class used internally by Diff to actually compute the diffs. + * + * The algorithm used here is mostly lifted from the perl module + * Algorithm::Diff (version 1.06) by Ned Konz, which is available at: + * http://www.perl.com/CPAN/authors/id/N/NE/NEDKONZ/Algorithm-Diff-1.06.zip + * + * More ideas are taken from: + * http://www.ics.uci.edu/~eppstein/161/960229.html + * + * Some ideas are (and a bit of code) are from from analyze.c, from GNU + * diffutils-2.7, which can be found at: + * ftp://gnudist.gnu.org/pub/gnu/diffutils/diffutils-2.7.tar.gz + * + * closingly, some ideas (subdivision by NCHUNKS > 2, and some optimizations) + * are my own. + * + * Line length limits for robustness added by Tim Starling, 2005-08-31 + * + * @author Geoffrey T. Dairiki, Tim Starling + * @private + * @subpackage DifferenceEngine + */ +class _DiffEngine { + function MAX_XREF_LENGTH() { + return 10000; + } + + function diff($from_lines, $to_lines) { + + $n_from = sizeof($from_lines); + $n_to = sizeof($to_lines); + + $this->xchanged = $this->ychanged = array(); + $this->xv = $this->yv = array(); + $this->xind = $this->yind = array(); + unset($this->seq); + unset($this->in_seq); + unset($this->lcs); + + // Skip leading common lines. + for ($skip = 0; $skip < $n_from && $skip < $n_to; $skip++) { + if ($from_lines[$skip] !== $to_lines[$skip]) { + break; + } + $this->xchanged[$skip] = $this->ychanged[$skip] = FALSE; + } + // Skip trailing common lines. + $xi = $n_from; + $yi = $n_to; + for ($endskip = 0; --$xi > $skip && --$yi > $skip; $endskip++) { + if ($from_lines[$xi] !== $to_lines[$yi]) { + break; + } + $this->xchanged[$xi] = $this->ychanged[$yi] = FALSE; + } + + // Ignore lines which do not exist in both files. + for ($xi = $skip; $xi < $n_from - $endskip; $xi++) { + $xhash[$this->_line_hash($from_lines[$xi])] = 1; + } + + for ($yi = $skip; $yi < $n_to - $endskip; $yi++) { + $line = $to_lines[$yi]; + if ($this->ychanged[$yi] = empty($xhash[$this->_line_hash($line)])) { + continue; + } + $yhash[$this->_line_hash($line)] = 1; + $this->yv[] = $line; + $this->yind[] = $yi; + } + for ($xi = $skip; $xi < $n_from - $endskip; $xi++) { + $line = $from_lines[$xi]; + if ($this->xchanged[$xi] = empty($yhash[$this->_line_hash($line)])) { + continue; + } + $this->xv[] = $line; + $this->xind[] = $xi; + } + + // Find the LCS. + $this->_compareseq(0, sizeof($this->xv), 0, sizeof($this->yv)); + + // Merge edits when possible + $this->_shift_boundaries($from_lines, $this->xchanged, $this->ychanged); + $this->_shift_boundaries($to_lines, $this->ychanged, $this->xchanged); + + // Compute the edit operations. + $edits = array(); + $xi = $yi = 0; + while ($xi < $n_from || $yi < $n_to) { + USE_ASSERTS && assert($yi < $n_to || $this->xchanged[$xi]); + USE_ASSERTS && assert($xi < $n_from || $this->ychanged[$yi]); + + // Skip matching "snake". + $copy = array(); + while ( $xi < $n_from && $yi < $n_to && !$this->xchanged[$xi] && !$this->ychanged[$yi]) { + $copy[] = $from_lines[$xi++]; + ++$yi; + } + if ($copy) { + $edits[] = new _DiffOp_Copy($copy); + } + // Find deletes & adds. + $delete = array(); + while ($xi < $n_from && $this->xchanged[$xi]) { + $_fl = $from_lines[$xi++]; + if (strlen($_fl)) { + $delete[] = $_fl; + } + } + $add = array(); + while ($yi < $n_to && $this->ychanged[$yi]) { + $_tl = $to_lines[$yi++]; + if (strlen($_tl)) { + $add[] = $_tl; + } + } + if ($delete && $add) { + $edits[] = new _DiffOp_Change($delete, $add); + } + elseif ($delete) { + $edits[] = new _DiffOp_Delete($delete); + } + elseif ($add) { + $edits[] = new _DiffOp_Add($add); + } + } + return $edits; + } + + /** + * Returns the whole line if it's small enough, or the MD5 hash otherwise. + */ + function _line_hash($line) { + if (drupal_strlen($line) > $this->MAX_XREF_LENGTH()) { + return md5($line); + } + else { + return $line; + } + } + + + /** + * Divide the Largest Common Subsequence (LCS) of the sequences + * [XOFF, XLIM) and [YOFF, YLIM) into NCHUNKS approximately equally + * sized segments. + * + * Returns (LCS, PTS). LCS is the length of the LCS. PTS is an + * array of NCHUNKS+1 (X, Y) indexes giving the diving points between + * sub sequences. The first sub-sequence is contained in [X0, X1), + * [Y0, Y1), the second in [X1, X2), [Y1, Y2) and so on. Note + * that (X0, Y0) == (XOFF, YOFF) and + * (X[NCHUNKS], Y[NCHUNKS]) == (XLIM, YLIM). + * + * This function assumes that the first lines of the specified portions + * of the two files do not match, and likewise that the last lines do not + * match. The caller must trim matching lines from the beginning and end + * of the portions it is going to specify. + */ + function _diag($xoff, $xlim, $yoff, $ylim, $nchunks) { + $flip = FALSE; + + if ($xlim - $xoff > $ylim - $yoff) { + // Things seems faster (I'm not sure I understand why) + // when the shortest sequence in X. + $flip = TRUE; + list($xoff, $xlim, $yoff, $ylim) = array($yoff, $ylim, $xoff, $xlim); + } + + if ($flip) { + for ($i = $ylim - 1; $i >= $yoff; $i--) { + $ymatches[$this->xv[$i]][] = $i; + } + } + else { + for ($i = $ylim - 1; $i >= $yoff; $i--) { + $ymatches[$this->yv[$i]][] = $i; + } + } + $this->lcs = 0; + $this->seq[0]= $yoff - 1; + $this->in_seq = array(); + $ymids[0] = array(); + + $numer = $xlim - $xoff + $nchunks - 1; + $x = $xoff; + for ($chunk = 0; $chunk < $nchunks; $chunk++) { + if ($chunk > 0) { + for ($i = 0; $i <= $this->lcs; $i++) { + $ymids[$i][$chunk-1] = $this->seq[$i]; + } + } + + $x1 = $xoff + (int)(($numer + ($xlim-$xoff)*$chunk) / $nchunks); + for ( ; $x < $x1; $x++) { + $line = $flip ? $this->yv[$x] : $this->xv[$x]; + if (empty($ymatches[$line])) { + continue; + } + $matches = $ymatches[$line]; + reset($matches); + while (list ($junk, $y) = each($matches)) { + if (empty($this->in_seq[$y])) { + $k = $this->_lcs_pos($y); + USE_ASSERTS && assert($k > 0); + $ymids[$k] = $ymids[$k-1]; + break; + } + } + while (list ($junk, $y) = each($matches)) { + if ($y > $this->seq[$k-1]) { + USE_ASSERTS && assert($y < $this->seq[$k]); + // Optimization: this is a common case: + // next match is just replacing previous match. + $this->in_seq[$this->seq[$k]] = FALSE; + $this->seq[$k] = $y; + $this->in_seq[$y] = 1; + } + elseif (empty($this->in_seq[$y])) { + $k = $this->_lcs_pos($y); + USE_ASSERTS && assert($k > 0); + $ymids[$k] = $ymids[$k-1]; + } + } + } + } + + $seps[] = $flip ? array($yoff, $xoff) : array($xoff, $yoff); + $ymid = $ymids[$this->lcs]; + for ($n = 0; $n < $nchunks - 1; $n++) { + $x1 = $xoff + (int)(($numer + ($xlim - $xoff) * $n) / $nchunks); + $y1 = $ymid[$n] + 1; + $seps[] = $flip ? array($y1, $x1) : array($x1, $y1); + } + $seps[] = $flip ? array($ylim, $xlim) : array($xlim, $ylim); + + return array($this->lcs, $seps); + } + + function _lcs_pos($ypos) { + + $end = $this->lcs; + if ($end == 0 || $ypos > $this->seq[$end]) { + $this->seq[++$this->lcs] = $ypos; + $this->in_seq[$ypos] = 1; + return $this->lcs; + } + + $beg = 1; + while ($beg < $end) { + $mid = (int)(($beg + $end) / 2); + if ($ypos > $this->seq[$mid]) { + $beg = $mid + 1; + } + else { + $end = $mid; + } + } + + USE_ASSERTS && assert($ypos != $this->seq[$end]); + + $this->in_seq[$this->seq[$end]] = FALSE; + $this->seq[$end] = $ypos; + $this->in_seq[$ypos] = 1; + return $end; + } + + /** + * Find LCS of two sequences. + * + * The results are recorded in the vectors $this->{x,y}changed[], by + * storing a 1 in the element for each line that is an insertion + * or deletion (ie. is not in the LCS). + * + * The subsequence of file 0 is [XOFF, XLIM) and likewise for file 1. + * + * Note that XLIM, YLIM are exclusive bounds. + * All line numbers are origin-0 and discarded lines are not counted. + */ + function _compareseq($xoff, $xlim, $yoff, $ylim) { + + // Slide down the bottom initial diagonal. + while ($xoff < $xlim && $yoff < $ylim && $this->xv[$xoff] == $this->yv[$yoff]) { + ++$xoff; + ++$yoff; + } + + // Slide up the top initial diagonal. + while ($xlim > $xoff && $ylim > $yoff && $this->xv[$xlim - 1] == $this->yv[$ylim - 1]) { + --$xlim; + --$ylim; + } + + if ($xoff == $xlim || $yoff == $ylim) { + $lcs = 0; + } + else { + // This is ad hoc but seems to work well. + //$nchunks = sqrt(min($xlim - $xoff, $ylim - $yoff) / 2.5); + //$nchunks = max(2, min(8, (int)$nchunks)); + $nchunks = min(7, $xlim - $xoff, $ylim - $yoff) + 1; + list($lcs, $seps) + = $this->_diag($xoff, $xlim, $yoff, $ylim, $nchunks); + } + + if ($lcs == 0) { + // X and Y sequences have no common subsequence: + // mark all changed. + while ($yoff < $ylim) { + $this->ychanged[$this->yind[$yoff++]] = 1; + } + while ($xoff < $xlim) { + $this->xchanged[$this->xind[$xoff++]] = 1; + } + } + else { + // Use the partitions to split this problem into subproblems. + reset($seps); + $pt1 = $seps[0]; + while ($pt2 = next($seps)) { + $this->_compareseq ($pt1[0], $pt2[0], $pt1[1], $pt2[1]); + $pt1 = $pt2; + } + } + } + + /** + * Adjust inserts/deletes of identical lines to join changes + * as much as possible. + * + * We do something when a run of changed lines include a + * line at one end and has an excluded, identical line at the other. + * We are free to choose which identical line is included. + * `compareseq' usually chooses the one at the beginning, + * but usually it is cleaner to consider the following identical line + * to be the "change". + * + * This is extracted verbatim from analyze.c (GNU diffutils-2.7). + */ + function _shift_boundaries($lines, &$changed, $other_changed) { + $i = 0; + $j = 0; + + USE_ASSERTS && assert('sizeof($lines) == sizeof($changed)'); + $len = sizeof($lines); + $other_len = sizeof($other_changed); + + while (1) { + /* + * Scan forwards to find beginning of another run of changes. + * Also keep track of the corresponding point in the other file. + * + * Throughout this code, $i and $j are adjusted together so that + * the first $i elements of $changed and the first $j elements + * of $other_changed both contain the same number of zeros + * (unchanged lines). + * Furthermore, $j is always kept so that $j == $other_len or + * $other_changed[$j] == FALSE. + */ + while ($j < $other_len && $other_changed[$j]) { + $j++; + } + while ($i < $len && ! $changed[$i]) { + USE_ASSERTS && assert('$j < $other_len && ! $other_changed[$j]'); + $i++; + $j++; + while ($j < $other_len && $other_changed[$j]) { + $j++; + } + } + + if ($i == $len) { + break; + } + $start = $i; + + // Find the end of this run of changes. + while (++$i < $len && $changed[$i]) { + continue; + } + + do { + /* + * Record the length of this run of changes, so that + * we can later determine whether the run has grown. + */ + $runlength = $i - $start; + + /* + * Move the changed region back, so long as the + * previous unchanged line matches the last changed one. + * This merges with previous changed regions. + */ + while ($start > 0 && $lines[$start - 1] == $lines[$i - 1]) { + $changed[--$start] = 1; + $changed[--$i] = FALSE; + while ($start > 0 && $changed[$start - 1]) { + $start--; + } + USE_ASSERTS && assert('$j > 0'); + while ($other_changed[--$j]) { + continue; + } + USE_ASSERTS && assert('$j >= 0 && !$other_changed[$j]'); + } + + /* + * Set CORRESPONDING to the end of the changed run, at the last + * point where it corresponds to a changed run in the other file. + * CORRESPONDING == LEN means no such point has been found. + */ + $corresponding = $j < $other_len ? $i : $len; + + /* + * Move the changed region forward, so long as the + * first changed line matches the following unchanged one. + * This merges with following changed regions. + * Do this second, so that if there are no merges, + * the changed region is moved forward as far as possible. + */ + while ($i < $len && $lines[$start] == $lines[$i]) { + $changed[$start++] = FALSE; + $changed[$i++] = 1; + while ($i < $len && $changed[$i]) { + $i++; + } + USE_ASSERTS && assert('$j < $other_len && ! $other_changed[$j]'); + $j++; + if ($j < $other_len && $other_changed[$j]) { + $corresponding = $i; + while ($j < $other_len && $other_changed[$j]) { + $j++; + } + } + } + } while ($runlength != $i - $start); + + /* + * If possible, move the fully-merged run of changes + * back to a corresponding run in the other file. + */ + while ($corresponding < $i) { + $changed[--$start] = 1; + $changed[--$i] = 0; + USE_ASSERTS && assert('$j > 0'); + while ($other_changed[--$j]) { + continue; + } + USE_ASSERTS && assert('$j >= 0 && !$other_changed[$j]'); + } + } + } +} + +/** + * Class representing a 'diff' between two sequences of strings. + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class Diff { + var $edits; + + /** + * Constructor. + * Computes diff between sequences of strings. + * + * @param $from_lines array An array of strings. + * (Typically these are lines from a file.) + * @param $to_lines array An array of strings. + */ + function Diff($from_lines, $to_lines) { + $eng = new _DiffEngine; + $this->edits = $eng->diff($from_lines, $to_lines); + //$this->_check($from_lines, $to_lines); + } + + /** + * Compute reversed Diff. + * + * SYNOPSIS: + * + * $diff = new Diff($lines1, $lines2); + * $rev = $diff->reverse(); + * @return object A Diff object representing the inverse of the + * original diff. + */ + function reverse() { + $rev = $this; + $rev->edits = array(); + foreach ($this->edits as $edit) { + $rev->edits[] = $edit->reverse(); + } + return $rev; + } + + /** + * Check for empty diff. + * + * @return bool True iff two sequences were identical. + */ + function isEmpty() { + foreach ($this->edits as $edit) { + if ($edit->type != 'copy') { + return FALSE; + } + } + return TRUE; + } + + /** + * Compute the length of the Longest Common Subsequence (LCS). + * + * This is mostly for diagnostic purposed. + * + * @return int The length of the LCS. + */ + function lcs() { + $lcs = 0; + foreach ($this->edits as $edit) { + if ($edit->type == 'copy') { + $lcs += sizeof($edit->orig); + } + } + return $lcs; + } + + /** + * Get the original set of lines. + * + * This reconstructs the $from_lines parameter passed to the + * constructor. + * + * @return array The original sequence of strings. + */ + function orig() { + $lines = array(); + + foreach ($this->edits as $edit) { + if ($edit->orig) { + array_splice($lines, sizeof($lines), 0, $edit->orig); + } + } + return $lines; + } + + /** + * Get the closing set of lines. + * + * This reconstructs the $to_lines parameter passed to the + * constructor. + * + * @return array The sequence of strings. + */ + function closing() { + $lines = array(); + + foreach ($this->edits as $edit) { + if ($edit->closing) { + array_splice($lines, sizeof($lines), 0, $edit->closing); + } + } + return $lines; + } + + /** + * Check a Diff for validity. + * + * This is here only for debugging purposes. + */ + function _check($from_lines, $to_lines) { + if (serialize($from_lines) != serialize($this->orig())) { + trigger_error("Reconstructed original doesn't match", E_USER_ERROR); + } + if (serialize($to_lines) != serialize($this->closing())) { + trigger_error("Reconstructed closing doesn't match", E_USER_ERROR); + } + + $rev = $this->reverse(); + if (serialize($to_lines) != serialize($rev->orig())) { + trigger_error("Reversed original doesn't match", E_USER_ERROR); + } + if (serialize($from_lines) != serialize($rev->closing())) { + trigger_error("Reversed closing doesn't match", E_USER_ERROR); + } + + + $prevtype = 'none'; + foreach ($this->edits as $edit) { + if ( $prevtype == $edit->type ) { + trigger_error("Edit sequence is non-optimal", E_USER_ERROR); + } + $prevtype = $edit->type; + } + + $lcs = $this->lcs(); + trigger_error('Diff okay: LCS = ' . $lcs, E_USER_NOTICE); + } +} + +/** + * FIXME: bad name. + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class MappedDiff extends Diff { + /** + * Constructor. + * + * Computes diff between sequences of strings. + * + * This can be used to compute things like + * case-insensitve diffs, or diffs which ignore + * changes in white-space. + * + * @param $from_lines array An array of strings. + * (Typically these are lines from a file.) + * + * @param $to_lines array An array of strings. + * + * @param $mapped_from_lines array This array should + * have the same size number of elements as $from_lines. + * The elements in $mapped_from_lines and + * $mapped_to_lines are what is actually compared + * when computing the diff. + * + * @param $mapped_to_lines array This array should + * have the same number of elements as $to_lines. + */ + function MappedDiff($from_lines, $to_lines, $mapped_from_lines, $mapped_to_lines) { + + assert(sizeof($from_lines) == sizeof($mapped_from_lines)); + assert(sizeof($to_lines) == sizeof($mapped_to_lines)); + + $this->Diff($mapped_from_lines, $mapped_to_lines); + + $xi = $yi = 0; + for ($i = 0; $i < sizeof($this->edits); $i++) { + $orig = &$this->edits[$i]->orig; + if (is_array($orig)) { + $orig = array_slice($from_lines, $xi, sizeof($orig)); + $xi += sizeof($orig); + } + + $closing = &$this->edits[$i]->closing; + if (is_array($closing)) { + $closing = array_slice($to_lines, $yi, sizeof($closing)); + $yi += sizeof($closing); + } + } + } +} + +/** + * A class to format Diffs + * + * This class formats the diff in classic diff format. + * It is intended that this class be customized via inheritance, + * to obtain fancier outputs. + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class DiffFormatter { + /** + * Should a block header be shown? + */ + var $show_header = TRUE; + + /** + * Number of leading context "lines" to preserve. + * + * This should be left at zero for this class, but subclasses + * may want to set this to other values. + */ + var $leading_context_lines = 0; + + /** + * Number of trailing context "lines" to preserve. + * + * This should be left at zero for this class, but subclasses + * may want to set this to other values. + */ + var $trailing_context_lines = 0; + + /** + * Format a diff. + * + * @param $diff object A Diff object. + * @return string The formatted output. + */ + function format($diff) { + $xi = $yi = 1; + $block = FALSE; + $context = array(); + + $nlead = $this->leading_context_lines; + $ntrail = $this->trailing_context_lines; + + $this->_start_diff(); + + foreach ($diff->edits as $edit) { + if ($edit->type == 'copy') { + if (is_array($block)) { + if (sizeof($edit->orig) <= $nlead + $ntrail) { + $block[] = $edit; + } + else { + if ($ntrail) { + $context = array_slice($edit->orig, 0, $ntrail); + $block[] = new _DiffOp_Copy($context); + } + $this->_block($x0, $ntrail + $xi - $x0, $y0, $ntrail + $yi - $y0, $block); + $block = FALSE; + } + } + $context = $edit->orig; + } + else { + if (! is_array($block)) { + $context = array_slice($context, sizeof($context) - $nlead); + $x0 = $xi - sizeof($context); + $y0 = $yi - sizeof($context); + $block = array(); + if ($context) { + $block[] = new _DiffOp_Copy($context); + } + } + $block[] = $edit; + } + + if ($edit->orig) { + $xi += sizeof($edit->orig); + } + if ($edit->closing) { + $yi += sizeof($edit->closing); + } + } + + if (is_array($block)) { + $this->_block($x0, $xi - $x0, $y0, $yi - $y0, $block); + } + $end = $this->_end_diff(); + + if (!empty($xi)) { + $this->line_stats['counter']['x'] += $xi; + } + if (!empty($yi)) { + $this->line_stats['counter']['y'] += $yi; + } + + return $end; + } + + function _block($xbeg, $xlen, $ybeg, $ylen, &$edits) { + $this->_start_block($this->_block_header($xbeg, $xlen, $ybeg, $ylen)); + foreach ($edits as $edit) { + if ($edit->type == 'copy') { + $this->_context($edit->orig); + } + elseif ($edit->type == 'add') { + $this->_added($edit->closing); + } + elseif ($edit->type == 'delete') { + $this->_deleted($edit->orig); + } + elseif ($edit->type == 'change') { + $this->_changed($edit->orig, $edit->closing); + } + else { + trigger_error('Unknown edit type', E_USER_ERROR); + } + } + $this->_end_block(); + } + + function _start_diff() { + ob_start(); + } + + function _end_diff() { + $val = ob_get_contents(); + ob_end_clean(); + return $val; + } + + function _block_header($xbeg, $xlen, $ybeg, $ylen) { + if ($xlen > 1) { + $xbeg .= "," . ($xbeg + $xlen - 1); + } + if ($ylen > 1) { + $ybeg .= "," . ($ybeg + $ylen - 1); + } + + return $xbeg . ($xlen ? ($ylen ? 'c' : 'd') : 'a') . $ybeg; + } + + function _start_block($header) { + if ($this->show_header) { + echo $header . "\n"; + } + } + + function _end_block() { + } + + function _lines($lines, $prefix = ' ') { + foreach ($lines as $line) { + echo "$prefix $line\n"; + } + } + + function _context($lines) { + $this->_lines($lines); + } + + function _added($lines) { + $this->_lines($lines, '>'); + } + function _deleted($lines) { + $this->_lines($lines, '<'); + } + + function _changed($orig, $closing) { + $this->_deleted($orig); + echo "---\n"; + $this->_added($closing); + } +} + + +/** + * Additions by Axel Boldt follow, partly taken from diff.php, phpwiki-1.3.3 + * + */ + +define('NBSP', ' '); // iso-8859-x non-breaking space. + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _HWLDF_WordAccumulator { + function _HWLDF_WordAccumulator() { + $this->_lines = array(); + $this->_line = ''; + $this->_group = ''; + $this->_tag = ''; + } + + function _flushGroup($new_tag) { + if ($this->_group !== '') { + if ($this->_tag == 'mark') { + $this->_line .= '' . check_plain($this->_group) . ''; + } + else { + $this->_line .= check_plain($this->_group); + } + } + $this->_group = ''; + $this->_tag = $new_tag; + } + + function _flushLine($new_tag) { + $this->_flushGroup($new_tag); + if ($this->_line != '') { + array_push($this->_lines, $this->_line); + } + else { + // make empty lines visible by inserting an NBSP + array_push($this->_lines, NBSP); + } + $this->_line = ''; + } + + function addWords($words, $tag = '') { + if ($tag != $this->_tag) { + $this->_flushGroup($tag); + } + foreach ($words as $word) { + // new-line should only come as first char of word. + if ($word == '') { + continue; + } + if ($word[0] == "\n") { + $this->_flushLine($tag); + $word = drupal_substr($word, 1); + } + assert(!strstr($word, "\n")); + $this->_group .= $word; + } + } + + function getLines() { + $this->_flushLine('~done'); + return $this->_lines; + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class WordLevelDiff extends MappedDiff { + function MAX_LINE_LENGTH() { + return 10000; + } + + function WordLevelDiff($orig_lines, $closing_lines) { + list($orig_words, $orig_stripped) = $this->_split($orig_lines); + list($closing_words, $closing_stripped) = $this->_split($closing_lines); + + $this->MappedDiff($orig_words, $closing_words, $orig_stripped, $closing_stripped); + } + + function _split($lines) { + $words = array(); + $stripped = array(); + $first = TRUE; + foreach ($lines as $line) { + // If the line is too long, just pretend the entire line is one big word + // This prevents resource exhaustion problems + if ( $first ) { + $first = FALSE; + } + else { + $words[] = "\n"; + $stripped[] = "\n"; + } + if ( drupal_strlen( $line ) > $this->MAX_LINE_LENGTH() ) { + $words[] = $line; + $stripped[] = $line; + } + else { + if (preg_match_all('/ ( [^\S\n]+ | [0-9_A-Za-z\x80-\xff]+ | . ) (?: (?!< \n) [^\S\n])? /xs', $line, $m)) { + $words = array_merge($words, $m[0]); + $stripped = array_merge($stripped, $m[1]); + } + } + } + return array($words, $stripped); + } + + function orig() { + $orig = new _HWLDF_WordAccumulator; + + foreach ($this->edits as $edit) { + if ($edit->type == 'copy') { + $orig->addWords($edit->orig); + } + elseif ($edit->orig) { + $orig->addWords($edit->orig, 'mark'); + } + } + $lines = $orig->getLines(); + return $lines; + } + + function closing() { + $closing = new _HWLDF_WordAccumulator; + + foreach ($this->edits as $edit) { + if ($edit->type == 'copy') { + $closing->addWords($edit->closing); + } + elseif ($edit->closing) { + $closing->addWords($edit->closing, 'mark'); + } + } + $lines = $closing->getLines(); + return $lines; + } +} + +/** + * Diff formatter which uses Drupal theme functions. + * @private + * @subpackage DifferenceEngine + */ +class DrupalDiffFormatter extends DiffFormatter { + + var $rows; + var $line_stats = array( + 'counter' => array('x' => 0, 'y' => 0), + 'offset' => array('x' => 0, 'y' => 0), + ); + + function DrupalDiffFormatter() { + $this->leading_context_lines = \Drupal::config('diff.settings')->get('diff_context_lines_leading'); + $this->trailing_context_lines = \Drupal::config('diff.settings')->get('diff_context_lines_trailing'); + } + + function _start_diff() { + $this->rows = array(); + } + + function _end_diff() { + return $this->rows; + } + + function _block_header($xbeg, $xlen, $ybeg, $ylen) { + return array( + array( + 'data' => _theme('diff_header_line', array('lineno' => $xbeg + $this->line_stats['offset']['x'])), + 'colspan' => 2, + ), + array( + 'data' => _theme('diff_header_line', array('lineno' => $ybeg + $this->line_stats['offset']['y'])), + 'colspan' => 2, + ) + ); + } + + function _start_block($header) { + if ($this->show_header) { + $this->rows[] = $header; + } + } + + function _end_block() { + } + + function _lines($lines, $prefix=' ', $color='white') { + } + + /** + * Note: you should HTML-escape parameter before calling this. + */ + function addedLine($line) { + return array( + array( + 'data' => '+', + 'class' => 'diff-marker', + ), + array( + 'data' => _theme('diff_content_line', array('line' => $line)), + 'class' => 'diff-context diff-addedline', + ) + ); + } + + /** + * Note: you should HTML-escape parameter before calling this. + */ + function deletedLine($line) { + return array( + array( + 'data' => '-', + 'class' => 'diff-marker', + ), + array( + 'data' => _theme('diff_content_line', array('line' => $line)), + 'class' => 'diff-context diff-deletedline', + ) + ); + } + + /** + * Note: you should HTML-escape parameter before calling this. + */ + function contextLine($line) { + return array( + ' ', + array( + 'data' => _theme('diff_content_line', array('line' => $line)), + 'class' => 'diff-context', + ) + ); + } + + function emptyLine() { + return array( + ' ', + _theme('diff_empty_line', array('line' => ' ')), + ); + } + + function _added($lines) { + foreach ($lines as $line) { + $this->rows[] = array_merge($this->emptyLine(), $this->addedLine(check_plain($line))); + } + } + + function _deleted($lines) { + foreach ($lines as $line) { + $this->rows[] = array_merge($this->deletedLine(check_plain($line)), $this->emptyLine()); + } + } + + function _context($lines) { + foreach ($lines as $line) { + $this->rows[] = array_merge($this->contextLine(check_plain($line)), $this->contextLine(check_plain($line))); + } + } + + function _changed($orig, $closing) { + $diff = new WordLevelDiff($orig, $closing); + $del = $diff->orig(); + $add = $diff->closing(); + + // Notice that WordLevelDiff returns HTML-escaped output. + // Hence, we will be calling addedLine/deletedLine without HTML-escaping. + + while ($line = array_shift($del)) { + $aline = array_shift( $add ); + $this->rows[] = array_merge($this->deletedLine($line), isset($aline) ? $this->addedLine($aline) : $this->emptyLine()); + } + foreach ($add as $line) { // If any leftovers + $this->rows[] = array_merge($this->emptyLine(), $this->addedLine($line)); + } + } +} + +/** + * Drupal inline Diff formatter. + * @private + * @subpackage DifferenceEngine + */ +class DrupalDiffInline { + var $a; + var $b; + + /** + * Constructor. + */ + function __construct($a, $b) { + $this->a = $a; + $this->b = $b; + } + + /** + * Render differences inline using HTML markup. + */ + function render() { + $a = preg_split('/(<[^>]+?>| )/', $this->a, -1, PREG_SPLIT_DELIM_CAPTURE); + $b = preg_split('/(<[^>]+?>| )/', $this->b, -1, PREG_SPLIT_DELIM_CAPTURE); + $diff = new Diff($a, $b); + $diff->edits = $this->process_edits($diff->edits); + + // Assemble highlighted output + $output = ''; + foreach ($diff->edits as $chunk) { + switch ($chunk->type) { + case 'copy': + $output .= implode('', $chunk->closing); + break; + case 'delete': + foreach ($chunk->orig as $i => $piece) { + if (strpos($piece, '<') === 0 && drupal_substr($piece, drupal_strlen($piece) - 1) === '>') { + $output .= $piece; + } + else { + $output .= _theme('diff_inline_chunk', array('text' => $piece, 'type' => $chunk->type)); + } + } + break; + default: + $chunk->closing = $this->process_chunk($chunk->closing); + foreach ($chunk->closing as $i => $piece) { + if ($piece === ' ' || (strpos($piece, '<') === 0 && drupal_substr($piece, drupal_strlen($piece) - 1) === '>' && drupal_strtolower(drupal_substr($piece, 1, 3)) != 'img')) { + $output .= $piece; + } + else { + $output .= _theme('diff_inline_chunk', array('text' => $piece, 'type' => $chunk->type)); + } + } + break; + } + } + return $output; + } + + /** + * Merge chunk segments between tag delimiters. + */ + function process_chunk($chunk) { + $processed = array(); + $j = 0; + foreach ($chunk as $i => $piece) { + $next = isset($chunk[$i+1]) ? $chunk[$i+1] : NULL; + if (!isset($processed[$j])) { + $processed[$j] = ''; + } + if (strpos($piece, '<') === 0 && drupal_substr($piece, drupal_strlen($piece) - 1) === '>') { + $processed[$j] = $piece; + $j++; + } + elseif (isset($next) && strpos($next, '<') === 0 && drupal_substr($next, drupal_strlen($next) - 1) === '>') { + $processed[$j] .= $piece; + $j++; + } + else { + $processed[$j] .= $piece; + } + } + return $processed; + } + + /** + * Merge copy and equivalent edits into intelligible chunks. + */ + function process_edits($edits) { + $processed = array(); + $current = array_shift($edits); + + // Make two passes -- first merge space delimiter copies back into their originals. + while ($chunk = array_shift($edits)) { + if ($chunk->type == 'copy' && $chunk->orig === array(' ')) { + $current->orig = array_merge((array) $current->orig, (array) $chunk->orig); + $current->closing = array_merge((array) $current->closing, (array) $chunk->closing); + } + else { + $processed[] = $current; + $current = $chunk; + } + } + $processed[] = $current; + + // Initial setup + $edits = $processed; + $processed = array(); + $current = array_shift($edits); + + // Second, merge equivalent chunks into each other. + while ($chunk = array_shift($edits)) { + if ($current->type == $chunk->type) { + $current->orig = array_merge((array) $current->orig, (array) $chunk->orig); + $current->closing = array_merge((array) $current->closing, (array) $chunk->closing); + } + else { + $processed[] = $current; + $current = $chunk; + } + } + $processed[] = $current; + + return $processed; + } +} diff --git a/src/_DiffOp_Copy.php b/src/_DiffOp_Copy.php new file mode 100644 index 0000000..f0c0d51 --- /dev/null +++ b/src/_DiffOp_Copy.php @@ -0,0 +1,1355 @@ + + * You may copy this code freely under the conditions of the GPL. + */ + +define('USE_ASSERTS', FALSE); + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp { + var $type; + var $orig; + var $closing; + + function reverse() { + trigger_error('pure virtual', E_USER_ERROR); + } + + function norig() { + return $this->orig ? sizeof($this->orig) : 0; + } + + function nclosing() { + return $this->closing ? sizeof($this->closing) : 0; + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Copy extends _DiffOp { + var $type = 'copy'; + + function _DiffOp_Copy($orig, $closing = FALSE) { + if (!is_array($closing)) { + $closing = $orig; + } + $this->orig = $orig; + $this->closing = $closing; + } + + function reverse() { + return new _DiffOp_Copy($this->closing, $this->orig); + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Delete extends _DiffOp { + var $type = 'delete'; + + function _DiffOp_Delete($lines) { + $this->orig = $lines; + $this->closing = FALSE; + } + + function reverse() { + return new _DiffOp_Add($this->orig); + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Add extends _DiffOp { + var $type = 'add'; + + function _DiffOp_Add($lines) { + $this->closing = $lines; + $this->orig = FALSE; + } + + function reverse() { + return new _DiffOp_Delete($this->closing); + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Change extends _DiffOp { + var $type = 'change'; + + function _DiffOp_Change($orig, $closing) { + $this->orig = $orig; + $this->closing = $closing; + } + + function reverse() { + return new _DiffOp_Change($this->closing, $this->orig); + } +} + + +/** + * Class used internally by Diff to actually compute the diffs. + * + * The algorithm used here is mostly lifted from the perl module + * Algorithm::Diff (version 1.06) by Ned Konz, which is available at: + * http://www.perl.com/CPAN/authors/id/N/NE/NEDKONZ/Algorithm-Diff-1.06.zip + * + * More ideas are taken from: + * http://www.ics.uci.edu/~eppstein/161/960229.html + * + * Some ideas are (and a bit of code) are from from analyze.c, from GNU + * diffutils-2.7, which can be found at: + * ftp://gnudist.gnu.org/pub/gnu/diffutils/diffutils-2.7.tar.gz + * + * closingly, some ideas (subdivision by NCHUNKS > 2, and some optimizations) + * are my own. + * + * Line length limits for robustness added by Tim Starling, 2005-08-31 + * + * @author Geoffrey T. Dairiki, Tim Starling + * @private + * @subpackage DifferenceEngine + */ +class _DiffEngine { + function MAX_XREF_LENGTH() { + return 10000; + } + + function diff($from_lines, $to_lines) { + + $n_from = sizeof($from_lines); + $n_to = sizeof($to_lines); + + $this->xchanged = $this->ychanged = array(); + $this->xv = $this->yv = array(); + $this->xind = $this->yind = array(); + unset($this->seq); + unset($this->in_seq); + unset($this->lcs); + + // Skip leading common lines. + for ($skip = 0; $skip < $n_from && $skip < $n_to; $skip++) { + if ($from_lines[$skip] !== $to_lines[$skip]) { + break; + } + $this->xchanged[$skip] = $this->ychanged[$skip] = FALSE; + } + // Skip trailing common lines. + $xi = $n_from; + $yi = $n_to; + for ($endskip = 0; --$xi > $skip && --$yi > $skip; $endskip++) { + if ($from_lines[$xi] !== $to_lines[$yi]) { + break; + } + $this->xchanged[$xi] = $this->ychanged[$yi] = FALSE; + } + + // Ignore lines which do not exist in both files. + for ($xi = $skip; $xi < $n_from - $endskip; $xi++) { + $xhash[$this->_line_hash($from_lines[$xi])] = 1; + } + + for ($yi = $skip; $yi < $n_to - $endskip; $yi++) { + $line = $to_lines[$yi]; + if ($this->ychanged[$yi] = empty($xhash[$this->_line_hash($line)])) { + continue; + } + $yhash[$this->_line_hash($line)] = 1; + $this->yv[] = $line; + $this->yind[] = $yi; + } + for ($xi = $skip; $xi < $n_from - $endskip; $xi++) { + $line = $from_lines[$xi]; + if ($this->xchanged[$xi] = empty($yhash[$this->_line_hash($line)])) { + continue; + } + $this->xv[] = $line; + $this->xind[] = $xi; + } + + // Find the LCS. + $this->_compareseq(0, sizeof($this->xv), 0, sizeof($this->yv)); + + // Merge edits when possible + $this->_shift_boundaries($from_lines, $this->xchanged, $this->ychanged); + $this->_shift_boundaries($to_lines, $this->ychanged, $this->xchanged); + + // Compute the edit operations. + $edits = array(); + $xi = $yi = 0; + while ($xi < $n_from || $yi < $n_to) { + USE_ASSERTS && assert($yi < $n_to || $this->xchanged[$xi]); + USE_ASSERTS && assert($xi < $n_from || $this->ychanged[$yi]); + + // Skip matching "snake". + $copy = array(); + while ( $xi < $n_from && $yi < $n_to && !$this->xchanged[$xi] && !$this->ychanged[$yi]) { + $copy[] = $from_lines[$xi++]; + ++$yi; + } + if ($copy) { + $edits[] = new _DiffOp_Copy($copy); + } + // Find deletes & adds. + $delete = array(); + while ($xi < $n_from && $this->xchanged[$xi]) { + $_fl = $from_lines[$xi++]; + if (strlen($_fl)) { + $delete[] = $_fl; + } + } + $add = array(); + while ($yi < $n_to && $this->ychanged[$yi]) { + $_tl = $to_lines[$yi++]; + if (strlen($_tl)) { + $add[] = $_tl; + } + } + if ($delete && $add) { + $edits[] = new _DiffOp_Change($delete, $add); + } + elseif ($delete) { + $edits[] = new _DiffOp_Delete($delete); + } + elseif ($add) { + $edits[] = new _DiffOp_Add($add); + } + } + return $edits; + } + + /** + * Returns the whole line if it's small enough, or the MD5 hash otherwise. + */ + function _line_hash($line) { + if (drupal_strlen($line) > $this->MAX_XREF_LENGTH()) { + return md5($line); + } + else { + return $line; + } + } + + + /** + * Divide the Largest Common Subsequence (LCS) of the sequences + * [XOFF, XLIM) and [YOFF, YLIM) into NCHUNKS approximately equally + * sized segments. + * + * Returns (LCS, PTS). LCS is the length of the LCS. PTS is an + * array of NCHUNKS+1 (X, Y) indexes giving the diving points between + * sub sequences. The first sub-sequence is contained in [X0, X1), + * [Y0, Y1), the second in [X1, X2), [Y1, Y2) and so on. Note + * that (X0, Y0) == (XOFF, YOFF) and + * (X[NCHUNKS], Y[NCHUNKS]) == (XLIM, YLIM). + * + * This function assumes that the first lines of the specified portions + * of the two files do not match, and likewise that the last lines do not + * match. The caller must trim matching lines from the beginning and end + * of the portions it is going to specify. + */ + function _diag($xoff, $xlim, $yoff, $ylim, $nchunks) { + $flip = FALSE; + + if ($xlim - $xoff > $ylim - $yoff) { + // Things seems faster (I'm not sure I understand why) + // when the shortest sequence in X. + $flip = TRUE; + list($xoff, $xlim, $yoff, $ylim) = array($yoff, $ylim, $xoff, $xlim); + } + + if ($flip) { + for ($i = $ylim - 1; $i >= $yoff; $i--) { + $ymatches[$this->xv[$i]][] = $i; + } + } + else { + for ($i = $ylim - 1; $i >= $yoff; $i--) { + $ymatches[$this->yv[$i]][] = $i; + } + } + $this->lcs = 0; + $this->seq[0]= $yoff - 1; + $this->in_seq = array(); + $ymids[0] = array(); + + $numer = $xlim - $xoff + $nchunks - 1; + $x = $xoff; + for ($chunk = 0; $chunk < $nchunks; $chunk++) { + if ($chunk > 0) { + for ($i = 0; $i <= $this->lcs; $i++) { + $ymids[$i][$chunk-1] = $this->seq[$i]; + } + } + + $x1 = $xoff + (int)(($numer + ($xlim-$xoff)*$chunk) / $nchunks); + for ( ; $x < $x1; $x++) { + $line = $flip ? $this->yv[$x] : $this->xv[$x]; + if (empty($ymatches[$line])) { + continue; + } + $matches = $ymatches[$line]; + reset($matches); + while (list ($junk, $y) = each($matches)) { + if (empty($this->in_seq[$y])) { + $k = $this->_lcs_pos($y); + USE_ASSERTS && assert($k > 0); + $ymids[$k] = $ymids[$k-1]; + break; + } + } + while (list ($junk, $y) = each($matches)) { + if ($y > $this->seq[$k-1]) { + USE_ASSERTS && assert($y < $this->seq[$k]); + // Optimization: this is a common case: + // next match is just replacing previous match. + $this->in_seq[$this->seq[$k]] = FALSE; + $this->seq[$k] = $y; + $this->in_seq[$y] = 1; + } + elseif (empty($this->in_seq[$y])) { + $k = $this->_lcs_pos($y); + USE_ASSERTS && assert($k > 0); + $ymids[$k] = $ymids[$k-1]; + } + } + } + } + + $seps[] = $flip ? array($yoff, $xoff) : array($xoff, $yoff); + $ymid = $ymids[$this->lcs]; + for ($n = 0; $n < $nchunks - 1; $n++) { + $x1 = $xoff + (int)(($numer + ($xlim - $xoff) * $n) / $nchunks); + $y1 = $ymid[$n] + 1; + $seps[] = $flip ? array($y1, $x1) : array($x1, $y1); + } + $seps[] = $flip ? array($ylim, $xlim) : array($xlim, $ylim); + + return array($this->lcs, $seps); + } + + function _lcs_pos($ypos) { + + $end = $this->lcs; + if ($end == 0 || $ypos > $this->seq[$end]) { + $this->seq[++$this->lcs] = $ypos; + $this->in_seq[$ypos] = 1; + return $this->lcs; + } + + $beg = 1; + while ($beg < $end) { + $mid = (int)(($beg + $end) / 2); + if ($ypos > $this->seq[$mid]) { + $beg = $mid + 1; + } + else { + $end = $mid; + } + } + + USE_ASSERTS && assert($ypos != $this->seq[$end]); + + $this->in_seq[$this->seq[$end]] = FALSE; + $this->seq[$end] = $ypos; + $this->in_seq[$ypos] = 1; + return $end; + } + + /** + * Find LCS of two sequences. + * + * The results are recorded in the vectors $this->{x,y}changed[], by + * storing a 1 in the element for each line that is an insertion + * or deletion (ie. is not in the LCS). + * + * The subsequence of file 0 is [XOFF, XLIM) and likewise for file 1. + * + * Note that XLIM, YLIM are exclusive bounds. + * All line numbers are origin-0 and discarded lines are not counted. + */ + function _compareseq($xoff, $xlim, $yoff, $ylim) { + + // Slide down the bottom initial diagonal. + while ($xoff < $xlim && $yoff < $ylim && $this->xv[$xoff] == $this->yv[$yoff]) { + ++$xoff; + ++$yoff; + } + + // Slide up the top initial diagonal. + while ($xlim > $xoff && $ylim > $yoff && $this->xv[$xlim - 1] == $this->yv[$ylim - 1]) { + --$xlim; + --$ylim; + } + + if ($xoff == $xlim || $yoff == $ylim) { + $lcs = 0; + } + else { + // This is ad hoc but seems to work well. + //$nchunks = sqrt(min($xlim - $xoff, $ylim - $yoff) / 2.5); + //$nchunks = max(2, min(8, (int)$nchunks)); + $nchunks = min(7, $xlim - $xoff, $ylim - $yoff) + 1; + list($lcs, $seps) + = $this->_diag($xoff, $xlim, $yoff, $ylim, $nchunks); + } + + if ($lcs == 0) { + // X and Y sequences have no common subsequence: + // mark all changed. + while ($yoff < $ylim) { + $this->ychanged[$this->yind[$yoff++]] = 1; + } + while ($xoff < $xlim) { + $this->xchanged[$this->xind[$xoff++]] = 1; + } + } + else { + // Use the partitions to split this problem into subproblems. + reset($seps); + $pt1 = $seps[0]; + while ($pt2 = next($seps)) { + $this->_compareseq ($pt1[0], $pt2[0], $pt1[1], $pt2[1]); + $pt1 = $pt2; + } + } + } + + /** + * Adjust inserts/deletes of identical lines to join changes + * as much as possible. + * + * We do something when a run of changed lines include a + * line at one end and has an excluded, identical line at the other. + * We are free to choose which identical line is included. + * `compareseq' usually chooses the one at the beginning, + * but usually it is cleaner to consider the following identical line + * to be the "change". + * + * This is extracted verbatim from analyze.c (GNU diffutils-2.7). + */ + function _shift_boundaries($lines, &$changed, $other_changed) { + $i = 0; + $j = 0; + + USE_ASSERTS && assert('sizeof($lines) == sizeof($changed)'); + $len = sizeof($lines); + $other_len = sizeof($other_changed); + + while (1) { + /* + * Scan forwards to find beginning of another run of changes. + * Also keep track of the corresponding point in the other file. + * + * Throughout this code, $i and $j are adjusted together so that + * the first $i elements of $changed and the first $j elements + * of $other_changed both contain the same number of zeros + * (unchanged lines). + * Furthermore, $j is always kept so that $j == $other_len or + * $other_changed[$j] == FALSE. + */ + while ($j < $other_len && $other_changed[$j]) { + $j++; + } + while ($i < $len && ! $changed[$i]) { + USE_ASSERTS && assert('$j < $other_len && ! $other_changed[$j]'); + $i++; + $j++; + while ($j < $other_len && $other_changed[$j]) { + $j++; + } + } + + if ($i == $len) { + break; + } + $start = $i; + + // Find the end of this run of changes. + while (++$i < $len && $changed[$i]) { + continue; + } + + do { + /* + * Record the length of this run of changes, so that + * we can later determine whether the run has grown. + */ + $runlength = $i - $start; + + /* + * Move the changed region back, so long as the + * previous unchanged line matches the last changed one. + * This merges with previous changed regions. + */ + while ($start > 0 && $lines[$start - 1] == $lines[$i - 1]) { + $changed[--$start] = 1; + $changed[--$i] = FALSE; + while ($start > 0 && $changed[$start - 1]) { + $start--; + } + USE_ASSERTS && assert('$j > 0'); + while ($other_changed[--$j]) { + continue; + } + USE_ASSERTS && assert('$j >= 0 && !$other_changed[$j]'); + } + + /* + * Set CORRESPONDING to the end of the changed run, at the last + * point where it corresponds to a changed run in the other file. + * CORRESPONDING == LEN means no such point has been found. + */ + $corresponding = $j < $other_len ? $i : $len; + + /* + * Move the changed region forward, so long as the + * first changed line matches the following unchanged one. + * This merges with following changed regions. + * Do this second, so that if there are no merges, + * the changed region is moved forward as far as possible. + */ + while ($i < $len && $lines[$start] == $lines[$i]) { + $changed[$start++] = FALSE; + $changed[$i++] = 1; + while ($i < $len && $changed[$i]) { + $i++; + } + USE_ASSERTS && assert('$j < $other_len && ! $other_changed[$j]'); + $j++; + if ($j < $other_len && $other_changed[$j]) { + $corresponding = $i; + while ($j < $other_len && $other_changed[$j]) { + $j++; + } + } + } + } while ($runlength != $i - $start); + + /* + * If possible, move the fully-merged run of changes + * back to a corresponding run in the other file. + */ + while ($corresponding < $i) { + $changed[--$start] = 1; + $changed[--$i] = 0; + USE_ASSERTS && assert('$j > 0'); + while ($other_changed[--$j]) { + continue; + } + USE_ASSERTS && assert('$j >= 0 && !$other_changed[$j]'); + } + } + } +} + +/** + * Class representing a 'diff' between two sequences of strings. + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class Diff { + var $edits; + + /** + * Constructor. + * Computes diff between sequences of strings. + * + * @param $from_lines array An array of strings. + * (Typically these are lines from a file.) + * @param $to_lines array An array of strings. + */ + function Diff($from_lines, $to_lines) { + $eng = new _DiffEngine; + $this->edits = $eng->diff($from_lines, $to_lines); + //$this->_check($from_lines, $to_lines); + } + + /** + * Compute reversed Diff. + * + * SYNOPSIS: + * + * $diff = new Diff($lines1, $lines2); + * $rev = $diff->reverse(); + * @return object A Diff object representing the inverse of the + * original diff. + */ + function reverse() { + $rev = $this; + $rev->edits = array(); + foreach ($this->edits as $edit) { + $rev->edits[] = $edit->reverse(); + } + return $rev; + } + + /** + * Check for empty diff. + * + * @return bool True iff two sequences were identical. + */ + function isEmpty() { + foreach ($this->edits as $edit) { + if ($edit->type != 'copy') { + return FALSE; + } + } + return TRUE; + } + + /** + * Compute the length of the Longest Common Subsequence (LCS). + * + * This is mostly for diagnostic purposed. + * + * @return int The length of the LCS. + */ + function lcs() { + $lcs = 0; + foreach ($this->edits as $edit) { + if ($edit->type == 'copy') { + $lcs += sizeof($edit->orig); + } + } + return $lcs; + } + + /** + * Get the original set of lines. + * + * This reconstructs the $from_lines parameter passed to the + * constructor. + * + * @return array The original sequence of strings. + */ + function orig() { + $lines = array(); + + foreach ($this->edits as $edit) { + if ($edit->orig) { + array_splice($lines, sizeof($lines), 0, $edit->orig); + } + } + return $lines; + } + + /** + * Get the closing set of lines. + * + * This reconstructs the $to_lines parameter passed to the + * constructor. + * + * @return array The sequence of strings. + */ + function closing() { + $lines = array(); + + foreach ($this->edits as $edit) { + if ($edit->closing) { + array_splice($lines, sizeof($lines), 0, $edit->closing); + } + } + return $lines; + } + + /** + * Check a Diff for validity. + * + * This is here only for debugging purposes. + */ + function _check($from_lines, $to_lines) { + if (serialize($from_lines) != serialize($this->orig())) { + trigger_error("Reconstructed original doesn't match", E_USER_ERROR); + } + if (serialize($to_lines) != serialize($this->closing())) { + trigger_error("Reconstructed closing doesn't match", E_USER_ERROR); + } + + $rev = $this->reverse(); + if (serialize($to_lines) != serialize($rev->orig())) { + trigger_error("Reversed original doesn't match", E_USER_ERROR); + } + if (serialize($from_lines) != serialize($rev->closing())) { + trigger_error("Reversed closing doesn't match", E_USER_ERROR); + } + + + $prevtype = 'none'; + foreach ($this->edits as $edit) { + if ( $prevtype == $edit->type ) { + trigger_error("Edit sequence is non-optimal", E_USER_ERROR); + } + $prevtype = $edit->type; + } + + $lcs = $this->lcs(); + trigger_error('Diff okay: LCS = ' . $lcs, E_USER_NOTICE); + } +} + +/** + * FIXME: bad name. + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class MappedDiff extends Diff { + /** + * Constructor. + * + * Computes diff between sequences of strings. + * + * This can be used to compute things like + * case-insensitve diffs, or diffs which ignore + * changes in white-space. + * + * @param $from_lines array An array of strings. + * (Typically these are lines from a file.) + * + * @param $to_lines array An array of strings. + * + * @param $mapped_from_lines array This array should + * have the same size number of elements as $from_lines. + * The elements in $mapped_from_lines and + * $mapped_to_lines are what is actually compared + * when computing the diff. + * + * @param $mapped_to_lines array This array should + * have the same number of elements as $to_lines. + */ + function MappedDiff($from_lines, $to_lines, $mapped_from_lines, $mapped_to_lines) { + + assert(sizeof($from_lines) == sizeof($mapped_from_lines)); + assert(sizeof($to_lines) == sizeof($mapped_to_lines)); + + $this->Diff($mapped_from_lines, $mapped_to_lines); + + $xi = $yi = 0; + for ($i = 0; $i < sizeof($this->edits); $i++) { + $orig = &$this->edits[$i]->orig; + if (is_array($orig)) { + $orig = array_slice($from_lines, $xi, sizeof($orig)); + $xi += sizeof($orig); + } + + $closing = &$this->edits[$i]->closing; + if (is_array($closing)) { + $closing = array_slice($to_lines, $yi, sizeof($closing)); + $yi += sizeof($closing); + } + } + } +} + +/** + * A class to format Diffs + * + * This class formats the diff in classic diff format. + * It is intended that this class be customized via inheritance, + * to obtain fancier outputs. + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class DiffFormatter { + /** + * Should a block header be shown? + */ + var $show_header = TRUE; + + /** + * Number of leading context "lines" to preserve. + * + * This should be left at zero for this class, but subclasses + * may want to set this to other values. + */ + var $leading_context_lines = 0; + + /** + * Number of trailing context "lines" to preserve. + * + * This should be left at zero for this class, but subclasses + * may want to set this to other values. + */ + var $trailing_context_lines = 0; + + /** + * Format a diff. + * + * @param $diff object A Diff object. + * @return string The formatted output. + */ + function format($diff) { + $xi = $yi = 1; + $block = FALSE; + $context = array(); + + $nlead = $this->leading_context_lines; + $ntrail = $this->trailing_context_lines; + + $this->_start_diff(); + + foreach ($diff->edits as $edit) { + if ($edit->type == 'copy') { + if (is_array($block)) { + if (sizeof($edit->orig) <= $nlead + $ntrail) { + $block[] = $edit; + } + else { + if ($ntrail) { + $context = array_slice($edit->orig, 0, $ntrail); + $block[] = new _DiffOp_Copy($context); + } + $this->_block($x0, $ntrail + $xi - $x0, $y0, $ntrail + $yi - $y0, $block); + $block = FALSE; + } + } + $context = $edit->orig; + } + else { + if (! is_array($block)) { + $context = array_slice($context, sizeof($context) - $nlead); + $x0 = $xi - sizeof($context); + $y0 = $yi - sizeof($context); + $block = array(); + if ($context) { + $block[] = new _DiffOp_Copy($context); + } + } + $block[] = $edit; + } + + if ($edit->orig) { + $xi += sizeof($edit->orig); + } + if ($edit->closing) { + $yi += sizeof($edit->closing); + } + } + + if (is_array($block)) { + $this->_block($x0, $xi - $x0, $y0, $yi - $y0, $block); + } + $end = $this->_end_diff(); + + if (!empty($xi)) { + $this->line_stats['counter']['x'] += $xi; + } + if (!empty($yi)) { + $this->line_stats['counter']['y'] += $yi; + } + + return $end; + } + + function _block($xbeg, $xlen, $ybeg, $ylen, &$edits) { + $this->_start_block($this->_block_header($xbeg, $xlen, $ybeg, $ylen)); + foreach ($edits as $edit) { + if ($edit->type == 'copy') { + $this->_context($edit->orig); + } + elseif ($edit->type == 'add') { + $this->_added($edit->closing); + } + elseif ($edit->type == 'delete') { + $this->_deleted($edit->orig); + } + elseif ($edit->type == 'change') { + $this->_changed($edit->orig, $edit->closing); + } + else { + trigger_error('Unknown edit type', E_USER_ERROR); + } + } + $this->_end_block(); + } + + function _start_diff() { + ob_start(); + } + + function _end_diff() { + $val = ob_get_contents(); + ob_end_clean(); + return $val; + } + + function _block_header($xbeg, $xlen, $ybeg, $ylen) { + if ($xlen > 1) { + $xbeg .= "," . ($xbeg + $xlen - 1); + } + if ($ylen > 1) { + $ybeg .= "," . ($ybeg + $ylen - 1); + } + + return $xbeg . ($xlen ? ($ylen ? 'c' : 'd') : 'a') . $ybeg; + } + + function _start_block($header) { + if ($this->show_header) { + echo $header . "\n"; + } + } + + function _end_block() { + } + + function _lines($lines, $prefix = ' ') { + foreach ($lines as $line) { + echo "$prefix $line\n"; + } + } + + function _context($lines) { + $this->_lines($lines); + } + + function _added($lines) { + $this->_lines($lines, '>'); + } + function _deleted($lines) { + $this->_lines($lines, '<'); + } + + function _changed($orig, $closing) { + $this->_deleted($orig); + echo "---\n"; + $this->_added($closing); + } +} + + +/** + * Additions by Axel Boldt follow, partly taken from diff.php, phpwiki-1.3.3 + * + */ + +define('NBSP', ' '); // iso-8859-x non-breaking space. + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _HWLDF_WordAccumulator { + function _HWLDF_WordAccumulator() { + $this->_lines = array(); + $this->_line = ''; + $this->_group = ''; + $this->_tag = ''; + } + + function _flushGroup($new_tag) { + if ($this->_group !== '') { + if ($this->_tag == 'mark') { + $this->_line .= '' . check_plain($this->_group) . ''; + } + else { + $this->_line .= check_plain($this->_group); + } + } + $this->_group = ''; + $this->_tag = $new_tag; + } + + function _flushLine($new_tag) { + $this->_flushGroup($new_tag); + if ($this->_line != '') { + array_push($this->_lines, $this->_line); + } + else { + // make empty lines visible by inserting an NBSP + array_push($this->_lines, NBSP); + } + $this->_line = ''; + } + + function addWords($words, $tag = '') { + if ($tag != $this->_tag) { + $this->_flushGroup($tag); + } + foreach ($words as $word) { + // new-line should only come as first char of word. + if ($word == '') { + continue; + } + if ($word[0] == "\n") { + $this->_flushLine($tag); + $word = drupal_substr($word, 1); + } + assert(!strstr($word, "\n")); + $this->_group .= $word; + } + } + + function getLines() { + $this->_flushLine('~done'); + return $this->_lines; + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class WordLevelDiff extends MappedDiff { + function MAX_LINE_LENGTH() { + return 10000; + } + + function WordLevelDiff($orig_lines, $closing_lines) { + list($orig_words, $orig_stripped) = $this->_split($orig_lines); + list($closing_words, $closing_stripped) = $this->_split($closing_lines); + + $this->MappedDiff($orig_words, $closing_words, $orig_stripped, $closing_stripped); + } + + function _split($lines) { + $words = array(); + $stripped = array(); + $first = TRUE; + foreach ($lines as $line) { + // If the line is too long, just pretend the entire line is one big word + // This prevents resource exhaustion problems + if ( $first ) { + $first = FALSE; + } + else { + $words[] = "\n"; + $stripped[] = "\n"; + } + if ( drupal_strlen( $line ) > $this->MAX_LINE_LENGTH() ) { + $words[] = $line; + $stripped[] = $line; + } + else { + if (preg_match_all('/ ( [^\S\n]+ | [0-9_A-Za-z\x80-\xff]+ | . ) (?: (?!< \n) [^\S\n])? /xs', $line, $m)) { + $words = array_merge($words, $m[0]); + $stripped = array_merge($stripped, $m[1]); + } + } + } + return array($words, $stripped); + } + + function orig() { + $orig = new _HWLDF_WordAccumulator; + + foreach ($this->edits as $edit) { + if ($edit->type == 'copy') { + $orig->addWords($edit->orig); + } + elseif ($edit->orig) { + $orig->addWords($edit->orig, 'mark'); + } + } + $lines = $orig->getLines(); + return $lines; + } + + function closing() { + $closing = new _HWLDF_WordAccumulator; + + foreach ($this->edits as $edit) { + if ($edit->type == 'copy') { + $closing->addWords($edit->closing); + } + elseif ($edit->closing) { + $closing->addWords($edit->closing, 'mark'); + } + } + $lines = $closing->getLines(); + return $lines; + } +} + +/** + * Diff formatter which uses Drupal theme functions. + * @private + * @subpackage DifferenceEngine + */ +class DrupalDiffFormatter extends DiffFormatter { + + var $rows; + var $line_stats = array( + 'counter' => array('x' => 0, 'y' => 0), + 'offset' => array('x' => 0, 'y' => 0), + ); + + function DrupalDiffFormatter() { + $this->leading_context_lines = \Drupal::config('diff.settings')->get('diff_context_lines_leading'); + $this->trailing_context_lines = \Drupal::config('diff.settings')->get('diff_context_lines_trailing'); + } + + function _start_diff() { + $this->rows = array(); + } + + function _end_diff() { + return $this->rows; + } + + function _block_header($xbeg, $xlen, $ybeg, $ylen) { + return array( + array( + 'data' => _theme('diff_header_line', array('lineno' => $xbeg + $this->line_stats['offset']['x'])), + 'colspan' => 2, + ), + array( + 'data' => _theme('diff_header_line', array('lineno' => $ybeg + $this->line_stats['offset']['y'])), + 'colspan' => 2, + ) + ); + } + + function _start_block($header) { + if ($this->show_header) { + $this->rows[] = $header; + } + } + + function _end_block() { + } + + function _lines($lines, $prefix=' ', $color='white') { + } + + /** + * Note: you should HTML-escape parameter before calling this. + */ + function addedLine($line) { + return array( + array( + 'data' => '+', + 'class' => 'diff-marker', + ), + array( + 'data' => _theme('diff_content_line', array('line' => $line)), + 'class' => 'diff-context diff-addedline', + ) + ); + } + + /** + * Note: you should HTML-escape parameter before calling this. + */ + function deletedLine($line) { + return array( + array( + 'data' => '-', + 'class' => 'diff-marker', + ), + array( + 'data' => _theme('diff_content_line', array('line' => $line)), + 'class' => 'diff-context diff-deletedline', + ) + ); + } + + /** + * Note: you should HTML-escape parameter before calling this. + */ + function contextLine($line) { + return array( + ' ', + array( + 'data' => _theme('diff_content_line', array('line' => $line)), + 'class' => 'diff-context', + ) + ); + } + + function emptyLine() { + return array( + ' ', + _theme('diff_empty_line', array('line' => ' ')), + ); + } + + function _added($lines) { + foreach ($lines as $line) { + $this->rows[] = array_merge($this->emptyLine(), $this->addedLine(check_plain($line))); + } + } + + function _deleted($lines) { + foreach ($lines as $line) { + $this->rows[] = array_merge($this->deletedLine(check_plain($line)), $this->emptyLine()); + } + } + + function _context($lines) { + foreach ($lines as $line) { + $this->rows[] = array_merge($this->contextLine(check_plain($line)), $this->contextLine(check_plain($line))); + } + } + + function _changed($orig, $closing) { + $diff = new WordLevelDiff($orig, $closing); + $del = $diff->orig(); + $add = $diff->closing(); + + // Notice that WordLevelDiff returns HTML-escaped output. + // Hence, we will be calling addedLine/deletedLine without HTML-escaping. + + while ($line = array_shift($del)) { + $aline = array_shift( $add ); + $this->rows[] = array_merge($this->deletedLine($line), isset($aline) ? $this->addedLine($aline) : $this->emptyLine()); + } + foreach ($add as $line) { // If any leftovers + $this->rows[] = array_merge($this->emptyLine(), $this->addedLine($line)); + } + } +} + +/** + * Drupal inline Diff formatter. + * @private + * @subpackage DifferenceEngine + */ +class DrupalDiffInline { + var $a; + var $b; + + /** + * Constructor. + */ + function __construct($a, $b) { + $this->a = $a; + $this->b = $b; + } + + /** + * Render differences inline using HTML markup. + */ + function render() { + $a = preg_split('/(<[^>]+?>| )/', $this->a, -1, PREG_SPLIT_DELIM_CAPTURE); + $b = preg_split('/(<[^>]+?>| )/', $this->b, -1, PREG_SPLIT_DELIM_CAPTURE); + $diff = new Diff($a, $b); + $diff->edits = $this->process_edits($diff->edits); + + // Assemble highlighted output + $output = ''; + foreach ($diff->edits as $chunk) { + switch ($chunk->type) { + case 'copy': + $output .= implode('', $chunk->closing); + break; + case 'delete': + foreach ($chunk->orig as $i => $piece) { + if (strpos($piece, '<') === 0 && drupal_substr($piece, drupal_strlen($piece) - 1) === '>') { + $output .= $piece; + } + else { + $output .= _theme('diff_inline_chunk', array('text' => $piece, 'type' => $chunk->type)); + } + } + break; + default: + $chunk->closing = $this->process_chunk($chunk->closing); + foreach ($chunk->closing as $i => $piece) { + if ($piece === ' ' || (strpos($piece, '<') === 0 && drupal_substr($piece, drupal_strlen($piece) - 1) === '>' && drupal_strtolower(drupal_substr($piece, 1, 3)) != 'img')) { + $output .= $piece; + } + else { + $output .= _theme('diff_inline_chunk', array('text' => $piece, 'type' => $chunk->type)); + } + } + break; + } + } + return $output; + } + + /** + * Merge chunk segments between tag delimiters. + */ + function process_chunk($chunk) { + $processed = array(); + $j = 0; + foreach ($chunk as $i => $piece) { + $next = isset($chunk[$i+1]) ? $chunk[$i+1] : NULL; + if (!isset($processed[$j])) { + $processed[$j] = ''; + } + if (strpos($piece, '<') === 0 && drupal_substr($piece, drupal_strlen($piece) - 1) === '>') { + $processed[$j] = $piece; + $j++; + } + elseif (isset($next) && strpos($next, '<') === 0 && drupal_substr($next, drupal_strlen($next) - 1) === '>') { + $processed[$j] .= $piece; + $j++; + } + else { + $processed[$j] .= $piece; + } + } + return $processed; + } + + /** + * Merge copy and equivalent edits into intelligible chunks. + */ + function process_edits($edits) { + $processed = array(); + $current = array_shift($edits); + + // Make two passes -- first merge space delimiter copies back into their originals. + while ($chunk = array_shift($edits)) { + if ($chunk->type == 'copy' && $chunk->orig === array(' ')) { + $current->orig = array_merge((array) $current->orig, (array) $chunk->orig); + $current->closing = array_merge((array) $current->closing, (array) $chunk->closing); + } + else { + $processed[] = $current; + $current = $chunk; + } + } + $processed[] = $current; + + // Initial setup + $edits = $processed; + $processed = array(); + $current = array_shift($edits); + + // Second, merge equivalent chunks into each other. + while ($chunk = array_shift($edits)) { + if ($current->type == $chunk->type) { + $current->orig = array_merge((array) $current->orig, (array) $chunk->orig); + $current->closing = array_merge((array) $current->closing, (array) $chunk->closing); + } + else { + $processed[] = $current; + $current = $chunk; + } + } + $processed[] = $current; + + return $processed; + } +} diff --git a/src/_DiffOp_Delete.php b/src/_DiffOp_Delete.php new file mode 100644 index 0000000..f0c0d51 --- /dev/null +++ b/src/_DiffOp_Delete.php @@ -0,0 +1,1355 @@ + + * You may copy this code freely under the conditions of the GPL. + */ + +define('USE_ASSERTS', FALSE); + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp { + var $type; + var $orig; + var $closing; + + function reverse() { + trigger_error('pure virtual', E_USER_ERROR); + } + + function norig() { + return $this->orig ? sizeof($this->orig) : 0; + } + + function nclosing() { + return $this->closing ? sizeof($this->closing) : 0; + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Copy extends _DiffOp { + var $type = 'copy'; + + function _DiffOp_Copy($orig, $closing = FALSE) { + if (!is_array($closing)) { + $closing = $orig; + } + $this->orig = $orig; + $this->closing = $closing; + } + + function reverse() { + return new _DiffOp_Copy($this->closing, $this->orig); + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Delete extends _DiffOp { + var $type = 'delete'; + + function _DiffOp_Delete($lines) { + $this->orig = $lines; + $this->closing = FALSE; + } + + function reverse() { + return new _DiffOp_Add($this->orig); + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Add extends _DiffOp { + var $type = 'add'; + + function _DiffOp_Add($lines) { + $this->closing = $lines; + $this->orig = FALSE; + } + + function reverse() { + return new _DiffOp_Delete($this->closing); + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Change extends _DiffOp { + var $type = 'change'; + + function _DiffOp_Change($orig, $closing) { + $this->orig = $orig; + $this->closing = $closing; + } + + function reverse() { + return new _DiffOp_Change($this->closing, $this->orig); + } +} + + +/** + * Class used internally by Diff to actually compute the diffs. + * + * The algorithm used here is mostly lifted from the perl module + * Algorithm::Diff (version 1.06) by Ned Konz, which is available at: + * http://www.perl.com/CPAN/authors/id/N/NE/NEDKONZ/Algorithm-Diff-1.06.zip + * + * More ideas are taken from: + * http://www.ics.uci.edu/~eppstein/161/960229.html + * + * Some ideas are (and a bit of code) are from from analyze.c, from GNU + * diffutils-2.7, which can be found at: + * ftp://gnudist.gnu.org/pub/gnu/diffutils/diffutils-2.7.tar.gz + * + * closingly, some ideas (subdivision by NCHUNKS > 2, and some optimizations) + * are my own. + * + * Line length limits for robustness added by Tim Starling, 2005-08-31 + * + * @author Geoffrey T. Dairiki, Tim Starling + * @private + * @subpackage DifferenceEngine + */ +class _DiffEngine { + function MAX_XREF_LENGTH() { + return 10000; + } + + function diff($from_lines, $to_lines) { + + $n_from = sizeof($from_lines); + $n_to = sizeof($to_lines); + + $this->xchanged = $this->ychanged = array(); + $this->xv = $this->yv = array(); + $this->xind = $this->yind = array(); + unset($this->seq); + unset($this->in_seq); + unset($this->lcs); + + // Skip leading common lines. + for ($skip = 0; $skip < $n_from && $skip < $n_to; $skip++) { + if ($from_lines[$skip] !== $to_lines[$skip]) { + break; + } + $this->xchanged[$skip] = $this->ychanged[$skip] = FALSE; + } + // Skip trailing common lines. + $xi = $n_from; + $yi = $n_to; + for ($endskip = 0; --$xi > $skip && --$yi > $skip; $endskip++) { + if ($from_lines[$xi] !== $to_lines[$yi]) { + break; + } + $this->xchanged[$xi] = $this->ychanged[$yi] = FALSE; + } + + // Ignore lines which do not exist in both files. + for ($xi = $skip; $xi < $n_from - $endskip; $xi++) { + $xhash[$this->_line_hash($from_lines[$xi])] = 1; + } + + for ($yi = $skip; $yi < $n_to - $endskip; $yi++) { + $line = $to_lines[$yi]; + if ($this->ychanged[$yi] = empty($xhash[$this->_line_hash($line)])) { + continue; + } + $yhash[$this->_line_hash($line)] = 1; + $this->yv[] = $line; + $this->yind[] = $yi; + } + for ($xi = $skip; $xi < $n_from - $endskip; $xi++) { + $line = $from_lines[$xi]; + if ($this->xchanged[$xi] = empty($yhash[$this->_line_hash($line)])) { + continue; + } + $this->xv[] = $line; + $this->xind[] = $xi; + } + + // Find the LCS. + $this->_compareseq(0, sizeof($this->xv), 0, sizeof($this->yv)); + + // Merge edits when possible + $this->_shift_boundaries($from_lines, $this->xchanged, $this->ychanged); + $this->_shift_boundaries($to_lines, $this->ychanged, $this->xchanged); + + // Compute the edit operations. + $edits = array(); + $xi = $yi = 0; + while ($xi < $n_from || $yi < $n_to) { + USE_ASSERTS && assert($yi < $n_to || $this->xchanged[$xi]); + USE_ASSERTS && assert($xi < $n_from || $this->ychanged[$yi]); + + // Skip matching "snake". + $copy = array(); + while ( $xi < $n_from && $yi < $n_to && !$this->xchanged[$xi] && !$this->ychanged[$yi]) { + $copy[] = $from_lines[$xi++]; + ++$yi; + } + if ($copy) { + $edits[] = new _DiffOp_Copy($copy); + } + // Find deletes & adds. + $delete = array(); + while ($xi < $n_from && $this->xchanged[$xi]) { + $_fl = $from_lines[$xi++]; + if (strlen($_fl)) { + $delete[] = $_fl; + } + } + $add = array(); + while ($yi < $n_to && $this->ychanged[$yi]) { + $_tl = $to_lines[$yi++]; + if (strlen($_tl)) { + $add[] = $_tl; + } + } + if ($delete && $add) { + $edits[] = new _DiffOp_Change($delete, $add); + } + elseif ($delete) { + $edits[] = new _DiffOp_Delete($delete); + } + elseif ($add) { + $edits[] = new _DiffOp_Add($add); + } + } + return $edits; + } + + /** + * Returns the whole line if it's small enough, or the MD5 hash otherwise. + */ + function _line_hash($line) { + if (drupal_strlen($line) > $this->MAX_XREF_LENGTH()) { + return md5($line); + } + else { + return $line; + } + } + + + /** + * Divide the Largest Common Subsequence (LCS) of the sequences + * [XOFF, XLIM) and [YOFF, YLIM) into NCHUNKS approximately equally + * sized segments. + * + * Returns (LCS, PTS). LCS is the length of the LCS. PTS is an + * array of NCHUNKS+1 (X, Y) indexes giving the diving points between + * sub sequences. The first sub-sequence is contained in [X0, X1), + * [Y0, Y1), the second in [X1, X2), [Y1, Y2) and so on. Note + * that (X0, Y0) == (XOFF, YOFF) and + * (X[NCHUNKS], Y[NCHUNKS]) == (XLIM, YLIM). + * + * This function assumes that the first lines of the specified portions + * of the two files do not match, and likewise that the last lines do not + * match. The caller must trim matching lines from the beginning and end + * of the portions it is going to specify. + */ + function _diag($xoff, $xlim, $yoff, $ylim, $nchunks) { + $flip = FALSE; + + if ($xlim - $xoff > $ylim - $yoff) { + // Things seems faster (I'm not sure I understand why) + // when the shortest sequence in X. + $flip = TRUE; + list($xoff, $xlim, $yoff, $ylim) = array($yoff, $ylim, $xoff, $xlim); + } + + if ($flip) { + for ($i = $ylim - 1; $i >= $yoff; $i--) { + $ymatches[$this->xv[$i]][] = $i; + } + } + else { + for ($i = $ylim - 1; $i >= $yoff; $i--) { + $ymatches[$this->yv[$i]][] = $i; + } + } + $this->lcs = 0; + $this->seq[0]= $yoff - 1; + $this->in_seq = array(); + $ymids[0] = array(); + + $numer = $xlim - $xoff + $nchunks - 1; + $x = $xoff; + for ($chunk = 0; $chunk < $nchunks; $chunk++) { + if ($chunk > 0) { + for ($i = 0; $i <= $this->lcs; $i++) { + $ymids[$i][$chunk-1] = $this->seq[$i]; + } + } + + $x1 = $xoff + (int)(($numer + ($xlim-$xoff)*$chunk) / $nchunks); + for ( ; $x < $x1; $x++) { + $line = $flip ? $this->yv[$x] : $this->xv[$x]; + if (empty($ymatches[$line])) { + continue; + } + $matches = $ymatches[$line]; + reset($matches); + while (list ($junk, $y) = each($matches)) { + if (empty($this->in_seq[$y])) { + $k = $this->_lcs_pos($y); + USE_ASSERTS && assert($k > 0); + $ymids[$k] = $ymids[$k-1]; + break; + } + } + while (list ($junk, $y) = each($matches)) { + if ($y > $this->seq[$k-1]) { + USE_ASSERTS && assert($y < $this->seq[$k]); + // Optimization: this is a common case: + // next match is just replacing previous match. + $this->in_seq[$this->seq[$k]] = FALSE; + $this->seq[$k] = $y; + $this->in_seq[$y] = 1; + } + elseif (empty($this->in_seq[$y])) { + $k = $this->_lcs_pos($y); + USE_ASSERTS && assert($k > 0); + $ymids[$k] = $ymids[$k-1]; + } + } + } + } + + $seps[] = $flip ? array($yoff, $xoff) : array($xoff, $yoff); + $ymid = $ymids[$this->lcs]; + for ($n = 0; $n < $nchunks - 1; $n++) { + $x1 = $xoff + (int)(($numer + ($xlim - $xoff) * $n) / $nchunks); + $y1 = $ymid[$n] + 1; + $seps[] = $flip ? array($y1, $x1) : array($x1, $y1); + } + $seps[] = $flip ? array($ylim, $xlim) : array($xlim, $ylim); + + return array($this->lcs, $seps); + } + + function _lcs_pos($ypos) { + + $end = $this->lcs; + if ($end == 0 || $ypos > $this->seq[$end]) { + $this->seq[++$this->lcs] = $ypos; + $this->in_seq[$ypos] = 1; + return $this->lcs; + } + + $beg = 1; + while ($beg < $end) { + $mid = (int)(($beg + $end) / 2); + if ($ypos > $this->seq[$mid]) { + $beg = $mid + 1; + } + else { + $end = $mid; + } + } + + USE_ASSERTS && assert($ypos != $this->seq[$end]); + + $this->in_seq[$this->seq[$end]] = FALSE; + $this->seq[$end] = $ypos; + $this->in_seq[$ypos] = 1; + return $end; + } + + /** + * Find LCS of two sequences. + * + * The results are recorded in the vectors $this->{x,y}changed[], by + * storing a 1 in the element for each line that is an insertion + * or deletion (ie. is not in the LCS). + * + * The subsequence of file 0 is [XOFF, XLIM) and likewise for file 1. + * + * Note that XLIM, YLIM are exclusive bounds. + * All line numbers are origin-0 and discarded lines are not counted. + */ + function _compareseq($xoff, $xlim, $yoff, $ylim) { + + // Slide down the bottom initial diagonal. + while ($xoff < $xlim && $yoff < $ylim && $this->xv[$xoff] == $this->yv[$yoff]) { + ++$xoff; + ++$yoff; + } + + // Slide up the top initial diagonal. + while ($xlim > $xoff && $ylim > $yoff && $this->xv[$xlim - 1] == $this->yv[$ylim - 1]) { + --$xlim; + --$ylim; + } + + if ($xoff == $xlim || $yoff == $ylim) { + $lcs = 0; + } + else { + // This is ad hoc but seems to work well. + //$nchunks = sqrt(min($xlim - $xoff, $ylim - $yoff) / 2.5); + //$nchunks = max(2, min(8, (int)$nchunks)); + $nchunks = min(7, $xlim - $xoff, $ylim - $yoff) + 1; + list($lcs, $seps) + = $this->_diag($xoff, $xlim, $yoff, $ylim, $nchunks); + } + + if ($lcs == 0) { + // X and Y sequences have no common subsequence: + // mark all changed. + while ($yoff < $ylim) { + $this->ychanged[$this->yind[$yoff++]] = 1; + } + while ($xoff < $xlim) { + $this->xchanged[$this->xind[$xoff++]] = 1; + } + } + else { + // Use the partitions to split this problem into subproblems. + reset($seps); + $pt1 = $seps[0]; + while ($pt2 = next($seps)) { + $this->_compareseq ($pt1[0], $pt2[0], $pt1[1], $pt2[1]); + $pt1 = $pt2; + } + } + } + + /** + * Adjust inserts/deletes of identical lines to join changes + * as much as possible. + * + * We do something when a run of changed lines include a + * line at one end and has an excluded, identical line at the other. + * We are free to choose which identical line is included. + * `compareseq' usually chooses the one at the beginning, + * but usually it is cleaner to consider the following identical line + * to be the "change". + * + * This is extracted verbatim from analyze.c (GNU diffutils-2.7). + */ + function _shift_boundaries($lines, &$changed, $other_changed) { + $i = 0; + $j = 0; + + USE_ASSERTS && assert('sizeof($lines) == sizeof($changed)'); + $len = sizeof($lines); + $other_len = sizeof($other_changed); + + while (1) { + /* + * Scan forwards to find beginning of another run of changes. + * Also keep track of the corresponding point in the other file. + * + * Throughout this code, $i and $j are adjusted together so that + * the first $i elements of $changed and the first $j elements + * of $other_changed both contain the same number of zeros + * (unchanged lines). + * Furthermore, $j is always kept so that $j == $other_len or + * $other_changed[$j] == FALSE. + */ + while ($j < $other_len && $other_changed[$j]) { + $j++; + } + while ($i < $len && ! $changed[$i]) { + USE_ASSERTS && assert('$j < $other_len && ! $other_changed[$j]'); + $i++; + $j++; + while ($j < $other_len && $other_changed[$j]) { + $j++; + } + } + + if ($i == $len) { + break; + } + $start = $i; + + // Find the end of this run of changes. + while (++$i < $len && $changed[$i]) { + continue; + } + + do { + /* + * Record the length of this run of changes, so that + * we can later determine whether the run has grown. + */ + $runlength = $i - $start; + + /* + * Move the changed region back, so long as the + * previous unchanged line matches the last changed one. + * This merges with previous changed regions. + */ + while ($start > 0 && $lines[$start - 1] == $lines[$i - 1]) { + $changed[--$start] = 1; + $changed[--$i] = FALSE; + while ($start > 0 && $changed[$start - 1]) { + $start--; + } + USE_ASSERTS && assert('$j > 0'); + while ($other_changed[--$j]) { + continue; + } + USE_ASSERTS && assert('$j >= 0 && !$other_changed[$j]'); + } + + /* + * Set CORRESPONDING to the end of the changed run, at the last + * point where it corresponds to a changed run in the other file. + * CORRESPONDING == LEN means no such point has been found. + */ + $corresponding = $j < $other_len ? $i : $len; + + /* + * Move the changed region forward, so long as the + * first changed line matches the following unchanged one. + * This merges with following changed regions. + * Do this second, so that if there are no merges, + * the changed region is moved forward as far as possible. + */ + while ($i < $len && $lines[$start] == $lines[$i]) { + $changed[$start++] = FALSE; + $changed[$i++] = 1; + while ($i < $len && $changed[$i]) { + $i++; + } + USE_ASSERTS && assert('$j < $other_len && ! $other_changed[$j]'); + $j++; + if ($j < $other_len && $other_changed[$j]) { + $corresponding = $i; + while ($j < $other_len && $other_changed[$j]) { + $j++; + } + } + } + } while ($runlength != $i - $start); + + /* + * If possible, move the fully-merged run of changes + * back to a corresponding run in the other file. + */ + while ($corresponding < $i) { + $changed[--$start] = 1; + $changed[--$i] = 0; + USE_ASSERTS && assert('$j > 0'); + while ($other_changed[--$j]) { + continue; + } + USE_ASSERTS && assert('$j >= 0 && !$other_changed[$j]'); + } + } + } +} + +/** + * Class representing a 'diff' between two sequences of strings. + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class Diff { + var $edits; + + /** + * Constructor. + * Computes diff between sequences of strings. + * + * @param $from_lines array An array of strings. + * (Typically these are lines from a file.) + * @param $to_lines array An array of strings. + */ + function Diff($from_lines, $to_lines) { + $eng = new _DiffEngine; + $this->edits = $eng->diff($from_lines, $to_lines); + //$this->_check($from_lines, $to_lines); + } + + /** + * Compute reversed Diff. + * + * SYNOPSIS: + * + * $diff = new Diff($lines1, $lines2); + * $rev = $diff->reverse(); + * @return object A Diff object representing the inverse of the + * original diff. + */ + function reverse() { + $rev = $this; + $rev->edits = array(); + foreach ($this->edits as $edit) { + $rev->edits[] = $edit->reverse(); + } + return $rev; + } + + /** + * Check for empty diff. + * + * @return bool True iff two sequences were identical. + */ + function isEmpty() { + foreach ($this->edits as $edit) { + if ($edit->type != 'copy') { + return FALSE; + } + } + return TRUE; + } + + /** + * Compute the length of the Longest Common Subsequence (LCS). + * + * This is mostly for diagnostic purposed. + * + * @return int The length of the LCS. + */ + function lcs() { + $lcs = 0; + foreach ($this->edits as $edit) { + if ($edit->type == 'copy') { + $lcs += sizeof($edit->orig); + } + } + return $lcs; + } + + /** + * Get the original set of lines. + * + * This reconstructs the $from_lines parameter passed to the + * constructor. + * + * @return array The original sequence of strings. + */ + function orig() { + $lines = array(); + + foreach ($this->edits as $edit) { + if ($edit->orig) { + array_splice($lines, sizeof($lines), 0, $edit->orig); + } + } + return $lines; + } + + /** + * Get the closing set of lines. + * + * This reconstructs the $to_lines parameter passed to the + * constructor. + * + * @return array The sequence of strings. + */ + function closing() { + $lines = array(); + + foreach ($this->edits as $edit) { + if ($edit->closing) { + array_splice($lines, sizeof($lines), 0, $edit->closing); + } + } + return $lines; + } + + /** + * Check a Diff for validity. + * + * This is here only for debugging purposes. + */ + function _check($from_lines, $to_lines) { + if (serialize($from_lines) != serialize($this->orig())) { + trigger_error("Reconstructed original doesn't match", E_USER_ERROR); + } + if (serialize($to_lines) != serialize($this->closing())) { + trigger_error("Reconstructed closing doesn't match", E_USER_ERROR); + } + + $rev = $this->reverse(); + if (serialize($to_lines) != serialize($rev->orig())) { + trigger_error("Reversed original doesn't match", E_USER_ERROR); + } + if (serialize($from_lines) != serialize($rev->closing())) { + trigger_error("Reversed closing doesn't match", E_USER_ERROR); + } + + + $prevtype = 'none'; + foreach ($this->edits as $edit) { + if ( $prevtype == $edit->type ) { + trigger_error("Edit sequence is non-optimal", E_USER_ERROR); + } + $prevtype = $edit->type; + } + + $lcs = $this->lcs(); + trigger_error('Diff okay: LCS = ' . $lcs, E_USER_NOTICE); + } +} + +/** + * FIXME: bad name. + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class MappedDiff extends Diff { + /** + * Constructor. + * + * Computes diff between sequences of strings. + * + * This can be used to compute things like + * case-insensitve diffs, or diffs which ignore + * changes in white-space. + * + * @param $from_lines array An array of strings. + * (Typically these are lines from a file.) + * + * @param $to_lines array An array of strings. + * + * @param $mapped_from_lines array This array should + * have the same size number of elements as $from_lines. + * The elements in $mapped_from_lines and + * $mapped_to_lines are what is actually compared + * when computing the diff. + * + * @param $mapped_to_lines array This array should + * have the same number of elements as $to_lines. + */ + function MappedDiff($from_lines, $to_lines, $mapped_from_lines, $mapped_to_lines) { + + assert(sizeof($from_lines) == sizeof($mapped_from_lines)); + assert(sizeof($to_lines) == sizeof($mapped_to_lines)); + + $this->Diff($mapped_from_lines, $mapped_to_lines); + + $xi = $yi = 0; + for ($i = 0; $i < sizeof($this->edits); $i++) { + $orig = &$this->edits[$i]->orig; + if (is_array($orig)) { + $orig = array_slice($from_lines, $xi, sizeof($orig)); + $xi += sizeof($orig); + } + + $closing = &$this->edits[$i]->closing; + if (is_array($closing)) { + $closing = array_slice($to_lines, $yi, sizeof($closing)); + $yi += sizeof($closing); + } + } + } +} + +/** + * A class to format Diffs + * + * This class formats the diff in classic diff format. + * It is intended that this class be customized via inheritance, + * to obtain fancier outputs. + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class DiffFormatter { + /** + * Should a block header be shown? + */ + var $show_header = TRUE; + + /** + * Number of leading context "lines" to preserve. + * + * This should be left at zero for this class, but subclasses + * may want to set this to other values. + */ + var $leading_context_lines = 0; + + /** + * Number of trailing context "lines" to preserve. + * + * This should be left at zero for this class, but subclasses + * may want to set this to other values. + */ + var $trailing_context_lines = 0; + + /** + * Format a diff. + * + * @param $diff object A Diff object. + * @return string The formatted output. + */ + function format($diff) { + $xi = $yi = 1; + $block = FALSE; + $context = array(); + + $nlead = $this->leading_context_lines; + $ntrail = $this->trailing_context_lines; + + $this->_start_diff(); + + foreach ($diff->edits as $edit) { + if ($edit->type == 'copy') { + if (is_array($block)) { + if (sizeof($edit->orig) <= $nlead + $ntrail) { + $block[] = $edit; + } + else { + if ($ntrail) { + $context = array_slice($edit->orig, 0, $ntrail); + $block[] = new _DiffOp_Copy($context); + } + $this->_block($x0, $ntrail + $xi - $x0, $y0, $ntrail + $yi - $y0, $block); + $block = FALSE; + } + } + $context = $edit->orig; + } + else { + if (! is_array($block)) { + $context = array_slice($context, sizeof($context) - $nlead); + $x0 = $xi - sizeof($context); + $y0 = $yi - sizeof($context); + $block = array(); + if ($context) { + $block[] = new _DiffOp_Copy($context); + } + } + $block[] = $edit; + } + + if ($edit->orig) { + $xi += sizeof($edit->orig); + } + if ($edit->closing) { + $yi += sizeof($edit->closing); + } + } + + if (is_array($block)) { + $this->_block($x0, $xi - $x0, $y0, $yi - $y0, $block); + } + $end = $this->_end_diff(); + + if (!empty($xi)) { + $this->line_stats['counter']['x'] += $xi; + } + if (!empty($yi)) { + $this->line_stats['counter']['y'] += $yi; + } + + return $end; + } + + function _block($xbeg, $xlen, $ybeg, $ylen, &$edits) { + $this->_start_block($this->_block_header($xbeg, $xlen, $ybeg, $ylen)); + foreach ($edits as $edit) { + if ($edit->type == 'copy') { + $this->_context($edit->orig); + } + elseif ($edit->type == 'add') { + $this->_added($edit->closing); + } + elseif ($edit->type == 'delete') { + $this->_deleted($edit->orig); + } + elseif ($edit->type == 'change') { + $this->_changed($edit->orig, $edit->closing); + } + else { + trigger_error('Unknown edit type', E_USER_ERROR); + } + } + $this->_end_block(); + } + + function _start_diff() { + ob_start(); + } + + function _end_diff() { + $val = ob_get_contents(); + ob_end_clean(); + return $val; + } + + function _block_header($xbeg, $xlen, $ybeg, $ylen) { + if ($xlen > 1) { + $xbeg .= "," . ($xbeg + $xlen - 1); + } + if ($ylen > 1) { + $ybeg .= "," . ($ybeg + $ylen - 1); + } + + return $xbeg . ($xlen ? ($ylen ? 'c' : 'd') : 'a') . $ybeg; + } + + function _start_block($header) { + if ($this->show_header) { + echo $header . "\n"; + } + } + + function _end_block() { + } + + function _lines($lines, $prefix = ' ') { + foreach ($lines as $line) { + echo "$prefix $line\n"; + } + } + + function _context($lines) { + $this->_lines($lines); + } + + function _added($lines) { + $this->_lines($lines, '>'); + } + function _deleted($lines) { + $this->_lines($lines, '<'); + } + + function _changed($orig, $closing) { + $this->_deleted($orig); + echo "---\n"; + $this->_added($closing); + } +} + + +/** + * Additions by Axel Boldt follow, partly taken from diff.php, phpwiki-1.3.3 + * + */ + +define('NBSP', ' '); // iso-8859-x non-breaking space. + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _HWLDF_WordAccumulator { + function _HWLDF_WordAccumulator() { + $this->_lines = array(); + $this->_line = ''; + $this->_group = ''; + $this->_tag = ''; + } + + function _flushGroup($new_tag) { + if ($this->_group !== '') { + if ($this->_tag == 'mark') { + $this->_line .= '' . check_plain($this->_group) . ''; + } + else { + $this->_line .= check_plain($this->_group); + } + } + $this->_group = ''; + $this->_tag = $new_tag; + } + + function _flushLine($new_tag) { + $this->_flushGroup($new_tag); + if ($this->_line != '') { + array_push($this->_lines, $this->_line); + } + else { + // make empty lines visible by inserting an NBSP + array_push($this->_lines, NBSP); + } + $this->_line = ''; + } + + function addWords($words, $tag = '') { + if ($tag != $this->_tag) { + $this->_flushGroup($tag); + } + foreach ($words as $word) { + // new-line should only come as first char of word. + if ($word == '') { + continue; + } + if ($word[0] == "\n") { + $this->_flushLine($tag); + $word = drupal_substr($word, 1); + } + assert(!strstr($word, "\n")); + $this->_group .= $word; + } + } + + function getLines() { + $this->_flushLine('~done'); + return $this->_lines; + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class WordLevelDiff extends MappedDiff { + function MAX_LINE_LENGTH() { + return 10000; + } + + function WordLevelDiff($orig_lines, $closing_lines) { + list($orig_words, $orig_stripped) = $this->_split($orig_lines); + list($closing_words, $closing_stripped) = $this->_split($closing_lines); + + $this->MappedDiff($orig_words, $closing_words, $orig_stripped, $closing_stripped); + } + + function _split($lines) { + $words = array(); + $stripped = array(); + $first = TRUE; + foreach ($lines as $line) { + // If the line is too long, just pretend the entire line is one big word + // This prevents resource exhaustion problems + if ( $first ) { + $first = FALSE; + } + else { + $words[] = "\n"; + $stripped[] = "\n"; + } + if ( drupal_strlen( $line ) > $this->MAX_LINE_LENGTH() ) { + $words[] = $line; + $stripped[] = $line; + } + else { + if (preg_match_all('/ ( [^\S\n]+ | [0-9_A-Za-z\x80-\xff]+ | . ) (?: (?!< \n) [^\S\n])? /xs', $line, $m)) { + $words = array_merge($words, $m[0]); + $stripped = array_merge($stripped, $m[1]); + } + } + } + return array($words, $stripped); + } + + function orig() { + $orig = new _HWLDF_WordAccumulator; + + foreach ($this->edits as $edit) { + if ($edit->type == 'copy') { + $orig->addWords($edit->orig); + } + elseif ($edit->orig) { + $orig->addWords($edit->orig, 'mark'); + } + } + $lines = $orig->getLines(); + return $lines; + } + + function closing() { + $closing = new _HWLDF_WordAccumulator; + + foreach ($this->edits as $edit) { + if ($edit->type == 'copy') { + $closing->addWords($edit->closing); + } + elseif ($edit->closing) { + $closing->addWords($edit->closing, 'mark'); + } + } + $lines = $closing->getLines(); + return $lines; + } +} + +/** + * Diff formatter which uses Drupal theme functions. + * @private + * @subpackage DifferenceEngine + */ +class DrupalDiffFormatter extends DiffFormatter { + + var $rows; + var $line_stats = array( + 'counter' => array('x' => 0, 'y' => 0), + 'offset' => array('x' => 0, 'y' => 0), + ); + + function DrupalDiffFormatter() { + $this->leading_context_lines = \Drupal::config('diff.settings')->get('diff_context_lines_leading'); + $this->trailing_context_lines = \Drupal::config('diff.settings')->get('diff_context_lines_trailing'); + } + + function _start_diff() { + $this->rows = array(); + } + + function _end_diff() { + return $this->rows; + } + + function _block_header($xbeg, $xlen, $ybeg, $ylen) { + return array( + array( + 'data' => _theme('diff_header_line', array('lineno' => $xbeg + $this->line_stats['offset']['x'])), + 'colspan' => 2, + ), + array( + 'data' => _theme('diff_header_line', array('lineno' => $ybeg + $this->line_stats['offset']['y'])), + 'colspan' => 2, + ) + ); + } + + function _start_block($header) { + if ($this->show_header) { + $this->rows[] = $header; + } + } + + function _end_block() { + } + + function _lines($lines, $prefix=' ', $color='white') { + } + + /** + * Note: you should HTML-escape parameter before calling this. + */ + function addedLine($line) { + return array( + array( + 'data' => '+', + 'class' => 'diff-marker', + ), + array( + 'data' => _theme('diff_content_line', array('line' => $line)), + 'class' => 'diff-context diff-addedline', + ) + ); + } + + /** + * Note: you should HTML-escape parameter before calling this. + */ + function deletedLine($line) { + return array( + array( + 'data' => '-', + 'class' => 'diff-marker', + ), + array( + 'data' => _theme('diff_content_line', array('line' => $line)), + 'class' => 'diff-context diff-deletedline', + ) + ); + } + + /** + * Note: you should HTML-escape parameter before calling this. + */ + function contextLine($line) { + return array( + ' ', + array( + 'data' => _theme('diff_content_line', array('line' => $line)), + 'class' => 'diff-context', + ) + ); + } + + function emptyLine() { + return array( + ' ', + _theme('diff_empty_line', array('line' => ' ')), + ); + } + + function _added($lines) { + foreach ($lines as $line) { + $this->rows[] = array_merge($this->emptyLine(), $this->addedLine(check_plain($line))); + } + } + + function _deleted($lines) { + foreach ($lines as $line) { + $this->rows[] = array_merge($this->deletedLine(check_plain($line)), $this->emptyLine()); + } + } + + function _context($lines) { + foreach ($lines as $line) { + $this->rows[] = array_merge($this->contextLine(check_plain($line)), $this->contextLine(check_plain($line))); + } + } + + function _changed($orig, $closing) { + $diff = new WordLevelDiff($orig, $closing); + $del = $diff->orig(); + $add = $diff->closing(); + + // Notice that WordLevelDiff returns HTML-escaped output. + // Hence, we will be calling addedLine/deletedLine without HTML-escaping. + + while ($line = array_shift($del)) { + $aline = array_shift( $add ); + $this->rows[] = array_merge($this->deletedLine($line), isset($aline) ? $this->addedLine($aline) : $this->emptyLine()); + } + foreach ($add as $line) { // If any leftovers + $this->rows[] = array_merge($this->emptyLine(), $this->addedLine($line)); + } + } +} + +/** + * Drupal inline Diff formatter. + * @private + * @subpackage DifferenceEngine + */ +class DrupalDiffInline { + var $a; + var $b; + + /** + * Constructor. + */ + function __construct($a, $b) { + $this->a = $a; + $this->b = $b; + } + + /** + * Render differences inline using HTML markup. + */ + function render() { + $a = preg_split('/(<[^>]+?>| )/', $this->a, -1, PREG_SPLIT_DELIM_CAPTURE); + $b = preg_split('/(<[^>]+?>| )/', $this->b, -1, PREG_SPLIT_DELIM_CAPTURE); + $diff = new Diff($a, $b); + $diff->edits = $this->process_edits($diff->edits); + + // Assemble highlighted output + $output = ''; + foreach ($diff->edits as $chunk) { + switch ($chunk->type) { + case 'copy': + $output .= implode('', $chunk->closing); + break; + case 'delete': + foreach ($chunk->orig as $i => $piece) { + if (strpos($piece, '<') === 0 && drupal_substr($piece, drupal_strlen($piece) - 1) === '>') { + $output .= $piece; + } + else { + $output .= _theme('diff_inline_chunk', array('text' => $piece, 'type' => $chunk->type)); + } + } + break; + default: + $chunk->closing = $this->process_chunk($chunk->closing); + foreach ($chunk->closing as $i => $piece) { + if ($piece === ' ' || (strpos($piece, '<') === 0 && drupal_substr($piece, drupal_strlen($piece) - 1) === '>' && drupal_strtolower(drupal_substr($piece, 1, 3)) != 'img')) { + $output .= $piece; + } + else { + $output .= _theme('diff_inline_chunk', array('text' => $piece, 'type' => $chunk->type)); + } + } + break; + } + } + return $output; + } + + /** + * Merge chunk segments between tag delimiters. + */ + function process_chunk($chunk) { + $processed = array(); + $j = 0; + foreach ($chunk as $i => $piece) { + $next = isset($chunk[$i+1]) ? $chunk[$i+1] : NULL; + if (!isset($processed[$j])) { + $processed[$j] = ''; + } + if (strpos($piece, '<') === 0 && drupal_substr($piece, drupal_strlen($piece) - 1) === '>') { + $processed[$j] = $piece; + $j++; + } + elseif (isset($next) && strpos($next, '<') === 0 && drupal_substr($next, drupal_strlen($next) - 1) === '>') { + $processed[$j] .= $piece; + $j++; + } + else { + $processed[$j] .= $piece; + } + } + return $processed; + } + + /** + * Merge copy and equivalent edits into intelligible chunks. + */ + function process_edits($edits) { + $processed = array(); + $current = array_shift($edits); + + // Make two passes -- first merge space delimiter copies back into their originals. + while ($chunk = array_shift($edits)) { + if ($chunk->type == 'copy' && $chunk->orig === array(' ')) { + $current->orig = array_merge((array) $current->orig, (array) $chunk->orig); + $current->closing = array_merge((array) $current->closing, (array) $chunk->closing); + } + else { + $processed[] = $current; + $current = $chunk; + } + } + $processed[] = $current; + + // Initial setup + $edits = $processed; + $processed = array(); + $current = array_shift($edits); + + // Second, merge equivalent chunks into each other. + while ($chunk = array_shift($edits)) { + if ($current->type == $chunk->type) { + $current->orig = array_merge((array) $current->orig, (array) $chunk->orig); + $current->closing = array_merge((array) $current->closing, (array) $chunk->closing); + } + else { + $processed[] = $current; + $current = $chunk; + } + } + $processed[] = $current; + + return $processed; + } +} diff --git a/src/_HWLDF_WordAccumulator.php b/src/_HWLDF_WordAccumulator.php new file mode 100644 index 0000000..f0c0d51 --- /dev/null +++ b/src/_HWLDF_WordAccumulator.php @@ -0,0 +1,1355 @@ + + * You may copy this code freely under the conditions of the GPL. + */ + +define('USE_ASSERTS', FALSE); + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp { + var $type; + var $orig; + var $closing; + + function reverse() { + trigger_error('pure virtual', E_USER_ERROR); + } + + function norig() { + return $this->orig ? sizeof($this->orig) : 0; + } + + function nclosing() { + return $this->closing ? sizeof($this->closing) : 0; + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Copy extends _DiffOp { + var $type = 'copy'; + + function _DiffOp_Copy($orig, $closing = FALSE) { + if (!is_array($closing)) { + $closing = $orig; + } + $this->orig = $orig; + $this->closing = $closing; + } + + function reverse() { + return new _DiffOp_Copy($this->closing, $this->orig); + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Delete extends _DiffOp { + var $type = 'delete'; + + function _DiffOp_Delete($lines) { + $this->orig = $lines; + $this->closing = FALSE; + } + + function reverse() { + return new _DiffOp_Add($this->orig); + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Add extends _DiffOp { + var $type = 'add'; + + function _DiffOp_Add($lines) { + $this->closing = $lines; + $this->orig = FALSE; + } + + function reverse() { + return new _DiffOp_Delete($this->closing); + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _DiffOp_Change extends _DiffOp { + var $type = 'change'; + + function _DiffOp_Change($orig, $closing) { + $this->orig = $orig; + $this->closing = $closing; + } + + function reverse() { + return new _DiffOp_Change($this->closing, $this->orig); + } +} + + +/** + * Class used internally by Diff to actually compute the diffs. + * + * The algorithm used here is mostly lifted from the perl module + * Algorithm::Diff (version 1.06) by Ned Konz, which is available at: + * http://www.perl.com/CPAN/authors/id/N/NE/NEDKONZ/Algorithm-Diff-1.06.zip + * + * More ideas are taken from: + * http://www.ics.uci.edu/~eppstein/161/960229.html + * + * Some ideas are (and a bit of code) are from from analyze.c, from GNU + * diffutils-2.7, which can be found at: + * ftp://gnudist.gnu.org/pub/gnu/diffutils/diffutils-2.7.tar.gz + * + * closingly, some ideas (subdivision by NCHUNKS > 2, and some optimizations) + * are my own. + * + * Line length limits for robustness added by Tim Starling, 2005-08-31 + * + * @author Geoffrey T. Dairiki, Tim Starling + * @private + * @subpackage DifferenceEngine + */ +class _DiffEngine { + function MAX_XREF_LENGTH() { + return 10000; + } + + function diff($from_lines, $to_lines) { + + $n_from = sizeof($from_lines); + $n_to = sizeof($to_lines); + + $this->xchanged = $this->ychanged = array(); + $this->xv = $this->yv = array(); + $this->xind = $this->yind = array(); + unset($this->seq); + unset($this->in_seq); + unset($this->lcs); + + // Skip leading common lines. + for ($skip = 0; $skip < $n_from && $skip < $n_to; $skip++) { + if ($from_lines[$skip] !== $to_lines[$skip]) { + break; + } + $this->xchanged[$skip] = $this->ychanged[$skip] = FALSE; + } + // Skip trailing common lines. + $xi = $n_from; + $yi = $n_to; + for ($endskip = 0; --$xi > $skip && --$yi > $skip; $endskip++) { + if ($from_lines[$xi] !== $to_lines[$yi]) { + break; + } + $this->xchanged[$xi] = $this->ychanged[$yi] = FALSE; + } + + // Ignore lines which do not exist in both files. + for ($xi = $skip; $xi < $n_from - $endskip; $xi++) { + $xhash[$this->_line_hash($from_lines[$xi])] = 1; + } + + for ($yi = $skip; $yi < $n_to - $endskip; $yi++) { + $line = $to_lines[$yi]; + if ($this->ychanged[$yi] = empty($xhash[$this->_line_hash($line)])) { + continue; + } + $yhash[$this->_line_hash($line)] = 1; + $this->yv[] = $line; + $this->yind[] = $yi; + } + for ($xi = $skip; $xi < $n_from - $endskip; $xi++) { + $line = $from_lines[$xi]; + if ($this->xchanged[$xi] = empty($yhash[$this->_line_hash($line)])) { + continue; + } + $this->xv[] = $line; + $this->xind[] = $xi; + } + + // Find the LCS. + $this->_compareseq(0, sizeof($this->xv), 0, sizeof($this->yv)); + + // Merge edits when possible + $this->_shift_boundaries($from_lines, $this->xchanged, $this->ychanged); + $this->_shift_boundaries($to_lines, $this->ychanged, $this->xchanged); + + // Compute the edit operations. + $edits = array(); + $xi = $yi = 0; + while ($xi < $n_from || $yi < $n_to) { + USE_ASSERTS && assert($yi < $n_to || $this->xchanged[$xi]); + USE_ASSERTS && assert($xi < $n_from || $this->ychanged[$yi]); + + // Skip matching "snake". + $copy = array(); + while ( $xi < $n_from && $yi < $n_to && !$this->xchanged[$xi] && !$this->ychanged[$yi]) { + $copy[] = $from_lines[$xi++]; + ++$yi; + } + if ($copy) { + $edits[] = new _DiffOp_Copy($copy); + } + // Find deletes & adds. + $delete = array(); + while ($xi < $n_from && $this->xchanged[$xi]) { + $_fl = $from_lines[$xi++]; + if (strlen($_fl)) { + $delete[] = $_fl; + } + } + $add = array(); + while ($yi < $n_to && $this->ychanged[$yi]) { + $_tl = $to_lines[$yi++]; + if (strlen($_tl)) { + $add[] = $_tl; + } + } + if ($delete && $add) { + $edits[] = new _DiffOp_Change($delete, $add); + } + elseif ($delete) { + $edits[] = new _DiffOp_Delete($delete); + } + elseif ($add) { + $edits[] = new _DiffOp_Add($add); + } + } + return $edits; + } + + /** + * Returns the whole line if it's small enough, or the MD5 hash otherwise. + */ + function _line_hash($line) { + if (drupal_strlen($line) > $this->MAX_XREF_LENGTH()) { + return md5($line); + } + else { + return $line; + } + } + + + /** + * Divide the Largest Common Subsequence (LCS) of the sequences + * [XOFF, XLIM) and [YOFF, YLIM) into NCHUNKS approximately equally + * sized segments. + * + * Returns (LCS, PTS). LCS is the length of the LCS. PTS is an + * array of NCHUNKS+1 (X, Y) indexes giving the diving points between + * sub sequences. The first sub-sequence is contained in [X0, X1), + * [Y0, Y1), the second in [X1, X2), [Y1, Y2) and so on. Note + * that (X0, Y0) == (XOFF, YOFF) and + * (X[NCHUNKS], Y[NCHUNKS]) == (XLIM, YLIM). + * + * This function assumes that the first lines of the specified portions + * of the two files do not match, and likewise that the last lines do not + * match. The caller must trim matching lines from the beginning and end + * of the portions it is going to specify. + */ + function _diag($xoff, $xlim, $yoff, $ylim, $nchunks) { + $flip = FALSE; + + if ($xlim - $xoff > $ylim - $yoff) { + // Things seems faster (I'm not sure I understand why) + // when the shortest sequence in X. + $flip = TRUE; + list($xoff, $xlim, $yoff, $ylim) = array($yoff, $ylim, $xoff, $xlim); + } + + if ($flip) { + for ($i = $ylim - 1; $i >= $yoff; $i--) { + $ymatches[$this->xv[$i]][] = $i; + } + } + else { + for ($i = $ylim - 1; $i >= $yoff; $i--) { + $ymatches[$this->yv[$i]][] = $i; + } + } + $this->lcs = 0; + $this->seq[0]= $yoff - 1; + $this->in_seq = array(); + $ymids[0] = array(); + + $numer = $xlim - $xoff + $nchunks - 1; + $x = $xoff; + for ($chunk = 0; $chunk < $nchunks; $chunk++) { + if ($chunk > 0) { + for ($i = 0; $i <= $this->lcs; $i++) { + $ymids[$i][$chunk-1] = $this->seq[$i]; + } + } + + $x1 = $xoff + (int)(($numer + ($xlim-$xoff)*$chunk) / $nchunks); + for ( ; $x < $x1; $x++) { + $line = $flip ? $this->yv[$x] : $this->xv[$x]; + if (empty($ymatches[$line])) { + continue; + } + $matches = $ymatches[$line]; + reset($matches); + while (list ($junk, $y) = each($matches)) { + if (empty($this->in_seq[$y])) { + $k = $this->_lcs_pos($y); + USE_ASSERTS && assert($k > 0); + $ymids[$k] = $ymids[$k-1]; + break; + } + } + while (list ($junk, $y) = each($matches)) { + if ($y > $this->seq[$k-1]) { + USE_ASSERTS && assert($y < $this->seq[$k]); + // Optimization: this is a common case: + // next match is just replacing previous match. + $this->in_seq[$this->seq[$k]] = FALSE; + $this->seq[$k] = $y; + $this->in_seq[$y] = 1; + } + elseif (empty($this->in_seq[$y])) { + $k = $this->_lcs_pos($y); + USE_ASSERTS && assert($k > 0); + $ymids[$k] = $ymids[$k-1]; + } + } + } + } + + $seps[] = $flip ? array($yoff, $xoff) : array($xoff, $yoff); + $ymid = $ymids[$this->lcs]; + for ($n = 0; $n < $nchunks - 1; $n++) { + $x1 = $xoff + (int)(($numer + ($xlim - $xoff) * $n) / $nchunks); + $y1 = $ymid[$n] + 1; + $seps[] = $flip ? array($y1, $x1) : array($x1, $y1); + } + $seps[] = $flip ? array($ylim, $xlim) : array($xlim, $ylim); + + return array($this->lcs, $seps); + } + + function _lcs_pos($ypos) { + + $end = $this->lcs; + if ($end == 0 || $ypos > $this->seq[$end]) { + $this->seq[++$this->lcs] = $ypos; + $this->in_seq[$ypos] = 1; + return $this->lcs; + } + + $beg = 1; + while ($beg < $end) { + $mid = (int)(($beg + $end) / 2); + if ($ypos > $this->seq[$mid]) { + $beg = $mid + 1; + } + else { + $end = $mid; + } + } + + USE_ASSERTS && assert($ypos != $this->seq[$end]); + + $this->in_seq[$this->seq[$end]] = FALSE; + $this->seq[$end] = $ypos; + $this->in_seq[$ypos] = 1; + return $end; + } + + /** + * Find LCS of two sequences. + * + * The results are recorded in the vectors $this->{x,y}changed[], by + * storing a 1 in the element for each line that is an insertion + * or deletion (ie. is not in the LCS). + * + * The subsequence of file 0 is [XOFF, XLIM) and likewise for file 1. + * + * Note that XLIM, YLIM are exclusive bounds. + * All line numbers are origin-0 and discarded lines are not counted. + */ + function _compareseq($xoff, $xlim, $yoff, $ylim) { + + // Slide down the bottom initial diagonal. + while ($xoff < $xlim && $yoff < $ylim && $this->xv[$xoff] == $this->yv[$yoff]) { + ++$xoff; + ++$yoff; + } + + // Slide up the top initial diagonal. + while ($xlim > $xoff && $ylim > $yoff && $this->xv[$xlim - 1] == $this->yv[$ylim - 1]) { + --$xlim; + --$ylim; + } + + if ($xoff == $xlim || $yoff == $ylim) { + $lcs = 0; + } + else { + // This is ad hoc but seems to work well. + //$nchunks = sqrt(min($xlim - $xoff, $ylim - $yoff) / 2.5); + //$nchunks = max(2, min(8, (int)$nchunks)); + $nchunks = min(7, $xlim - $xoff, $ylim - $yoff) + 1; + list($lcs, $seps) + = $this->_diag($xoff, $xlim, $yoff, $ylim, $nchunks); + } + + if ($lcs == 0) { + // X and Y sequences have no common subsequence: + // mark all changed. + while ($yoff < $ylim) { + $this->ychanged[$this->yind[$yoff++]] = 1; + } + while ($xoff < $xlim) { + $this->xchanged[$this->xind[$xoff++]] = 1; + } + } + else { + // Use the partitions to split this problem into subproblems. + reset($seps); + $pt1 = $seps[0]; + while ($pt2 = next($seps)) { + $this->_compareseq ($pt1[0], $pt2[0], $pt1[1], $pt2[1]); + $pt1 = $pt2; + } + } + } + + /** + * Adjust inserts/deletes of identical lines to join changes + * as much as possible. + * + * We do something when a run of changed lines include a + * line at one end and has an excluded, identical line at the other. + * We are free to choose which identical line is included. + * `compareseq' usually chooses the one at the beginning, + * but usually it is cleaner to consider the following identical line + * to be the "change". + * + * This is extracted verbatim from analyze.c (GNU diffutils-2.7). + */ + function _shift_boundaries($lines, &$changed, $other_changed) { + $i = 0; + $j = 0; + + USE_ASSERTS && assert('sizeof($lines) == sizeof($changed)'); + $len = sizeof($lines); + $other_len = sizeof($other_changed); + + while (1) { + /* + * Scan forwards to find beginning of another run of changes. + * Also keep track of the corresponding point in the other file. + * + * Throughout this code, $i and $j are adjusted together so that + * the first $i elements of $changed and the first $j elements + * of $other_changed both contain the same number of zeros + * (unchanged lines). + * Furthermore, $j is always kept so that $j == $other_len or + * $other_changed[$j] == FALSE. + */ + while ($j < $other_len && $other_changed[$j]) { + $j++; + } + while ($i < $len && ! $changed[$i]) { + USE_ASSERTS && assert('$j < $other_len && ! $other_changed[$j]'); + $i++; + $j++; + while ($j < $other_len && $other_changed[$j]) { + $j++; + } + } + + if ($i == $len) { + break; + } + $start = $i; + + // Find the end of this run of changes. + while (++$i < $len && $changed[$i]) { + continue; + } + + do { + /* + * Record the length of this run of changes, so that + * we can later determine whether the run has grown. + */ + $runlength = $i - $start; + + /* + * Move the changed region back, so long as the + * previous unchanged line matches the last changed one. + * This merges with previous changed regions. + */ + while ($start > 0 && $lines[$start - 1] == $lines[$i - 1]) { + $changed[--$start] = 1; + $changed[--$i] = FALSE; + while ($start > 0 && $changed[$start - 1]) { + $start--; + } + USE_ASSERTS && assert('$j > 0'); + while ($other_changed[--$j]) { + continue; + } + USE_ASSERTS && assert('$j >= 0 && !$other_changed[$j]'); + } + + /* + * Set CORRESPONDING to the end of the changed run, at the last + * point where it corresponds to a changed run in the other file. + * CORRESPONDING == LEN means no such point has been found. + */ + $corresponding = $j < $other_len ? $i : $len; + + /* + * Move the changed region forward, so long as the + * first changed line matches the following unchanged one. + * This merges with following changed regions. + * Do this second, so that if there are no merges, + * the changed region is moved forward as far as possible. + */ + while ($i < $len && $lines[$start] == $lines[$i]) { + $changed[$start++] = FALSE; + $changed[$i++] = 1; + while ($i < $len && $changed[$i]) { + $i++; + } + USE_ASSERTS && assert('$j < $other_len && ! $other_changed[$j]'); + $j++; + if ($j < $other_len && $other_changed[$j]) { + $corresponding = $i; + while ($j < $other_len && $other_changed[$j]) { + $j++; + } + } + } + } while ($runlength != $i - $start); + + /* + * If possible, move the fully-merged run of changes + * back to a corresponding run in the other file. + */ + while ($corresponding < $i) { + $changed[--$start] = 1; + $changed[--$i] = 0; + USE_ASSERTS && assert('$j > 0'); + while ($other_changed[--$j]) { + continue; + } + USE_ASSERTS && assert('$j >= 0 && !$other_changed[$j]'); + } + } + } +} + +/** + * Class representing a 'diff' between two sequences of strings. + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class Diff { + var $edits; + + /** + * Constructor. + * Computes diff between sequences of strings. + * + * @param $from_lines array An array of strings. + * (Typically these are lines from a file.) + * @param $to_lines array An array of strings. + */ + function Diff($from_lines, $to_lines) { + $eng = new _DiffEngine; + $this->edits = $eng->diff($from_lines, $to_lines); + //$this->_check($from_lines, $to_lines); + } + + /** + * Compute reversed Diff. + * + * SYNOPSIS: + * + * $diff = new Diff($lines1, $lines2); + * $rev = $diff->reverse(); + * @return object A Diff object representing the inverse of the + * original diff. + */ + function reverse() { + $rev = $this; + $rev->edits = array(); + foreach ($this->edits as $edit) { + $rev->edits[] = $edit->reverse(); + } + return $rev; + } + + /** + * Check for empty diff. + * + * @return bool True iff two sequences were identical. + */ + function isEmpty() { + foreach ($this->edits as $edit) { + if ($edit->type != 'copy') { + return FALSE; + } + } + return TRUE; + } + + /** + * Compute the length of the Longest Common Subsequence (LCS). + * + * This is mostly for diagnostic purposed. + * + * @return int The length of the LCS. + */ + function lcs() { + $lcs = 0; + foreach ($this->edits as $edit) { + if ($edit->type == 'copy') { + $lcs += sizeof($edit->orig); + } + } + return $lcs; + } + + /** + * Get the original set of lines. + * + * This reconstructs the $from_lines parameter passed to the + * constructor. + * + * @return array The original sequence of strings. + */ + function orig() { + $lines = array(); + + foreach ($this->edits as $edit) { + if ($edit->orig) { + array_splice($lines, sizeof($lines), 0, $edit->orig); + } + } + return $lines; + } + + /** + * Get the closing set of lines. + * + * This reconstructs the $to_lines parameter passed to the + * constructor. + * + * @return array The sequence of strings. + */ + function closing() { + $lines = array(); + + foreach ($this->edits as $edit) { + if ($edit->closing) { + array_splice($lines, sizeof($lines), 0, $edit->closing); + } + } + return $lines; + } + + /** + * Check a Diff for validity. + * + * This is here only for debugging purposes. + */ + function _check($from_lines, $to_lines) { + if (serialize($from_lines) != serialize($this->orig())) { + trigger_error("Reconstructed original doesn't match", E_USER_ERROR); + } + if (serialize($to_lines) != serialize($this->closing())) { + trigger_error("Reconstructed closing doesn't match", E_USER_ERROR); + } + + $rev = $this->reverse(); + if (serialize($to_lines) != serialize($rev->orig())) { + trigger_error("Reversed original doesn't match", E_USER_ERROR); + } + if (serialize($from_lines) != serialize($rev->closing())) { + trigger_error("Reversed closing doesn't match", E_USER_ERROR); + } + + + $prevtype = 'none'; + foreach ($this->edits as $edit) { + if ( $prevtype == $edit->type ) { + trigger_error("Edit sequence is non-optimal", E_USER_ERROR); + } + $prevtype = $edit->type; + } + + $lcs = $this->lcs(); + trigger_error('Diff okay: LCS = ' . $lcs, E_USER_NOTICE); + } +} + +/** + * FIXME: bad name. + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class MappedDiff extends Diff { + /** + * Constructor. + * + * Computes diff between sequences of strings. + * + * This can be used to compute things like + * case-insensitve diffs, or diffs which ignore + * changes in white-space. + * + * @param $from_lines array An array of strings. + * (Typically these are lines from a file.) + * + * @param $to_lines array An array of strings. + * + * @param $mapped_from_lines array This array should + * have the same size number of elements as $from_lines. + * The elements in $mapped_from_lines and + * $mapped_to_lines are what is actually compared + * when computing the diff. + * + * @param $mapped_to_lines array This array should + * have the same number of elements as $to_lines. + */ + function MappedDiff($from_lines, $to_lines, $mapped_from_lines, $mapped_to_lines) { + + assert(sizeof($from_lines) == sizeof($mapped_from_lines)); + assert(sizeof($to_lines) == sizeof($mapped_to_lines)); + + $this->Diff($mapped_from_lines, $mapped_to_lines); + + $xi = $yi = 0; + for ($i = 0; $i < sizeof($this->edits); $i++) { + $orig = &$this->edits[$i]->orig; + if (is_array($orig)) { + $orig = array_slice($from_lines, $xi, sizeof($orig)); + $xi += sizeof($orig); + } + + $closing = &$this->edits[$i]->closing; + if (is_array($closing)) { + $closing = array_slice($to_lines, $yi, sizeof($closing)); + $yi += sizeof($closing); + } + } + } +} + +/** + * A class to format Diffs + * + * This class formats the diff in classic diff format. + * It is intended that this class be customized via inheritance, + * to obtain fancier outputs. + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class DiffFormatter { + /** + * Should a block header be shown? + */ + var $show_header = TRUE; + + /** + * Number of leading context "lines" to preserve. + * + * This should be left at zero for this class, but subclasses + * may want to set this to other values. + */ + var $leading_context_lines = 0; + + /** + * Number of trailing context "lines" to preserve. + * + * This should be left at zero for this class, but subclasses + * may want to set this to other values. + */ + var $trailing_context_lines = 0; + + /** + * Format a diff. + * + * @param $diff object A Diff object. + * @return string The formatted output. + */ + function format($diff) { + $xi = $yi = 1; + $block = FALSE; + $context = array(); + + $nlead = $this->leading_context_lines; + $ntrail = $this->trailing_context_lines; + + $this->_start_diff(); + + foreach ($diff->edits as $edit) { + if ($edit->type == 'copy') { + if (is_array($block)) { + if (sizeof($edit->orig) <= $nlead + $ntrail) { + $block[] = $edit; + } + else { + if ($ntrail) { + $context = array_slice($edit->orig, 0, $ntrail); + $block[] = new _DiffOp_Copy($context); + } + $this->_block($x0, $ntrail + $xi - $x0, $y0, $ntrail + $yi - $y0, $block); + $block = FALSE; + } + } + $context = $edit->orig; + } + else { + if (! is_array($block)) { + $context = array_slice($context, sizeof($context) - $nlead); + $x0 = $xi - sizeof($context); + $y0 = $yi - sizeof($context); + $block = array(); + if ($context) { + $block[] = new _DiffOp_Copy($context); + } + } + $block[] = $edit; + } + + if ($edit->orig) { + $xi += sizeof($edit->orig); + } + if ($edit->closing) { + $yi += sizeof($edit->closing); + } + } + + if (is_array($block)) { + $this->_block($x0, $xi - $x0, $y0, $yi - $y0, $block); + } + $end = $this->_end_diff(); + + if (!empty($xi)) { + $this->line_stats['counter']['x'] += $xi; + } + if (!empty($yi)) { + $this->line_stats['counter']['y'] += $yi; + } + + return $end; + } + + function _block($xbeg, $xlen, $ybeg, $ylen, &$edits) { + $this->_start_block($this->_block_header($xbeg, $xlen, $ybeg, $ylen)); + foreach ($edits as $edit) { + if ($edit->type == 'copy') { + $this->_context($edit->orig); + } + elseif ($edit->type == 'add') { + $this->_added($edit->closing); + } + elseif ($edit->type == 'delete') { + $this->_deleted($edit->orig); + } + elseif ($edit->type == 'change') { + $this->_changed($edit->orig, $edit->closing); + } + else { + trigger_error('Unknown edit type', E_USER_ERROR); + } + } + $this->_end_block(); + } + + function _start_diff() { + ob_start(); + } + + function _end_diff() { + $val = ob_get_contents(); + ob_end_clean(); + return $val; + } + + function _block_header($xbeg, $xlen, $ybeg, $ylen) { + if ($xlen > 1) { + $xbeg .= "," . ($xbeg + $xlen - 1); + } + if ($ylen > 1) { + $ybeg .= "," . ($ybeg + $ylen - 1); + } + + return $xbeg . ($xlen ? ($ylen ? 'c' : 'd') : 'a') . $ybeg; + } + + function _start_block($header) { + if ($this->show_header) { + echo $header . "\n"; + } + } + + function _end_block() { + } + + function _lines($lines, $prefix = ' ') { + foreach ($lines as $line) { + echo "$prefix $line\n"; + } + } + + function _context($lines) { + $this->_lines($lines); + } + + function _added($lines) { + $this->_lines($lines, '>'); + } + function _deleted($lines) { + $this->_lines($lines, '<'); + } + + function _changed($orig, $closing) { + $this->_deleted($orig); + echo "---\n"; + $this->_added($closing); + } +} + + +/** + * Additions by Axel Boldt follow, partly taken from diff.php, phpwiki-1.3.3 + * + */ + +define('NBSP', ' '); // iso-8859-x non-breaking space. + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class _HWLDF_WordAccumulator { + function _HWLDF_WordAccumulator() { + $this->_lines = array(); + $this->_line = ''; + $this->_group = ''; + $this->_tag = ''; + } + + function _flushGroup($new_tag) { + if ($this->_group !== '') { + if ($this->_tag == 'mark') { + $this->_line .= '' . check_plain($this->_group) . ''; + } + else { + $this->_line .= check_plain($this->_group); + } + } + $this->_group = ''; + $this->_tag = $new_tag; + } + + function _flushLine($new_tag) { + $this->_flushGroup($new_tag); + if ($this->_line != '') { + array_push($this->_lines, $this->_line); + } + else { + // make empty lines visible by inserting an NBSP + array_push($this->_lines, NBSP); + } + $this->_line = ''; + } + + function addWords($words, $tag = '') { + if ($tag != $this->_tag) { + $this->_flushGroup($tag); + } + foreach ($words as $word) { + // new-line should only come as first char of word. + if ($word == '') { + continue; + } + if ($word[0] == "\n") { + $this->_flushLine($tag); + $word = drupal_substr($word, 1); + } + assert(!strstr($word, "\n")); + $this->_group .= $word; + } + } + + function getLines() { + $this->_flushLine('~done'); + return $this->_lines; + } +} + +/** + * @todo document + * @private + * @subpackage DifferenceEngine + */ +class WordLevelDiff extends MappedDiff { + function MAX_LINE_LENGTH() { + return 10000; + } + + function WordLevelDiff($orig_lines, $closing_lines) { + list($orig_words, $orig_stripped) = $this->_split($orig_lines); + list($closing_words, $closing_stripped) = $this->_split($closing_lines); + + $this->MappedDiff($orig_words, $closing_words, $orig_stripped, $closing_stripped); + } + + function _split($lines) { + $words = array(); + $stripped = array(); + $first = TRUE; + foreach ($lines as $line) { + // If the line is too long, just pretend the entire line is one big word + // This prevents resource exhaustion problems + if ( $first ) { + $first = FALSE; + } + else { + $words[] = "\n"; + $stripped[] = "\n"; + } + if ( drupal_strlen( $line ) > $this->MAX_LINE_LENGTH() ) { + $words[] = $line; + $stripped[] = $line; + } + else { + if (preg_match_all('/ ( [^\S\n]+ | [0-9_A-Za-z\x80-\xff]+ | . ) (?: (?!< \n) [^\S\n])? /xs', $line, $m)) { + $words = array_merge($words, $m[0]); + $stripped = array_merge($stripped, $m[1]); + } + } + } + return array($words, $stripped); + } + + function orig() { + $orig = new _HWLDF_WordAccumulator; + + foreach ($this->edits as $edit) { + if ($edit->type == 'copy') { + $orig->addWords($edit->orig); + } + elseif ($edit->orig) { + $orig->addWords($edit->orig, 'mark'); + } + } + $lines = $orig->getLines(); + return $lines; + } + + function closing() { + $closing = new _HWLDF_WordAccumulator; + + foreach ($this->edits as $edit) { + if ($edit->type == 'copy') { + $closing->addWords($edit->closing); + } + elseif ($edit->closing) { + $closing->addWords($edit->closing, 'mark'); + } + } + $lines = $closing->getLines(); + return $lines; + } +} + +/** + * Diff formatter which uses Drupal theme functions. + * @private + * @subpackage DifferenceEngine + */ +class DrupalDiffFormatter extends DiffFormatter { + + var $rows; + var $line_stats = array( + 'counter' => array('x' => 0, 'y' => 0), + 'offset' => array('x' => 0, 'y' => 0), + ); + + function DrupalDiffFormatter() { + $this->leading_context_lines = \Drupal::config('diff.settings')->get('diff_context_lines_leading'); + $this->trailing_context_lines = \Drupal::config('diff.settings')->get('diff_context_lines_trailing'); + } + + function _start_diff() { + $this->rows = array(); + } + + function _end_diff() { + return $this->rows; + } + + function _block_header($xbeg, $xlen, $ybeg, $ylen) { + return array( + array( + 'data' => _theme('diff_header_line', array('lineno' => $xbeg + $this->line_stats['offset']['x'])), + 'colspan' => 2, + ), + array( + 'data' => _theme('diff_header_line', array('lineno' => $ybeg + $this->line_stats['offset']['y'])), + 'colspan' => 2, + ) + ); + } + + function _start_block($header) { + if ($this->show_header) { + $this->rows[] = $header; + } + } + + function _end_block() { + } + + function _lines($lines, $prefix=' ', $color='white') { + } + + /** + * Note: you should HTML-escape parameter before calling this. + */ + function addedLine($line) { + return array( + array( + 'data' => '+', + 'class' => 'diff-marker', + ), + array( + 'data' => _theme('diff_content_line', array('line' => $line)), + 'class' => 'diff-context diff-addedline', + ) + ); + } + + /** + * Note: you should HTML-escape parameter before calling this. + */ + function deletedLine($line) { + return array( + array( + 'data' => '-', + 'class' => 'diff-marker', + ), + array( + 'data' => _theme('diff_content_line', array('line' => $line)), + 'class' => 'diff-context diff-deletedline', + ) + ); + } + + /** + * Note: you should HTML-escape parameter before calling this. + */ + function contextLine($line) { + return array( + ' ', + array( + 'data' => _theme('diff_content_line', array('line' => $line)), + 'class' => 'diff-context', + ) + ); + } + + function emptyLine() { + return array( + ' ', + _theme('diff_empty_line', array('line' => ' ')), + ); + } + + function _added($lines) { + foreach ($lines as $line) { + $this->rows[] = array_merge($this->emptyLine(), $this->addedLine(check_plain($line))); + } + } + + function _deleted($lines) { + foreach ($lines as $line) { + $this->rows[] = array_merge($this->deletedLine(check_plain($line)), $this->emptyLine()); + } + } + + function _context($lines) { + foreach ($lines as $line) { + $this->rows[] = array_merge($this->contextLine(check_plain($line)), $this->contextLine(check_plain($line))); + } + } + + function _changed($orig, $closing) { + $diff = new WordLevelDiff($orig, $closing); + $del = $diff->orig(); + $add = $diff->closing(); + + // Notice that WordLevelDiff returns HTML-escaped output. + // Hence, we will be calling addedLine/deletedLine without HTML-escaping. + + while ($line = array_shift($del)) { + $aline = array_shift( $add ); + $this->rows[] = array_merge($this->deletedLine($line), isset($aline) ? $this->addedLine($aline) : $this->emptyLine()); + } + foreach ($add as $line) { // If any leftovers + $this->rows[] = array_merge($this->emptyLine(), $this->addedLine($line)); + } + } +} + +/** + * Drupal inline Diff formatter. + * @private + * @subpackage DifferenceEngine + */ +class DrupalDiffInline { + var $a; + var $b; + + /** + * Constructor. + */ + function __construct($a, $b) { + $this->a = $a; + $this->b = $b; + } + + /** + * Render differences inline using HTML markup. + */ + function render() { + $a = preg_split('/(<[^>]+?>| )/', $this->a, -1, PREG_SPLIT_DELIM_CAPTURE); + $b = preg_split('/(<[^>]+?>| )/', $this->b, -1, PREG_SPLIT_DELIM_CAPTURE); + $diff = new Diff($a, $b); + $diff->edits = $this->process_edits($diff->edits); + + // Assemble highlighted output + $output = ''; + foreach ($diff->edits as $chunk) { + switch ($chunk->type) { + case 'copy': + $output .= implode('', $chunk->closing); + break; + case 'delete': + foreach ($chunk->orig as $i => $piece) { + if (strpos($piece, '<') === 0 && drupal_substr($piece, drupal_strlen($piece) - 1) === '>') { + $output .= $piece; + } + else { + $output .= _theme('diff_inline_chunk', array('text' => $piece, 'type' => $chunk->type)); + } + } + break; + default: + $chunk->closing = $this->process_chunk($chunk->closing); + foreach ($chunk->closing as $i => $piece) { + if ($piece === ' ' || (strpos($piece, '<') === 0 && drupal_substr($piece, drupal_strlen($piece) - 1) === '>' && drupal_strtolower(drupal_substr($piece, 1, 3)) != 'img')) { + $output .= $piece; + } + else { + $output .= _theme('diff_inline_chunk', array('text' => $piece, 'type' => $chunk->type)); + } + } + break; + } + } + return $output; + } + + /** + * Merge chunk segments between tag delimiters. + */ + function process_chunk($chunk) { + $processed = array(); + $j = 0; + foreach ($chunk as $i => $piece) { + $next = isset($chunk[$i+1]) ? $chunk[$i+1] : NULL; + if (!isset($processed[$j])) { + $processed[$j] = ''; + } + if (strpos($piece, '<') === 0 && drupal_substr($piece, drupal_strlen($piece) - 1) === '>') { + $processed[$j] = $piece; + $j++; + } + elseif (isset($next) && strpos($next, '<') === 0 && drupal_substr($next, drupal_strlen($next) - 1) === '>') { + $processed[$j] .= $piece; + $j++; + } + else { + $processed[$j] .= $piece; + } + } + return $processed; + } + + /** + * Merge copy and equivalent edits into intelligible chunks. + */ + function process_edits($edits) { + $processed = array(); + $current = array_shift($edits); + + // Make two passes -- first merge space delimiter copies back into their originals. + while ($chunk = array_shift($edits)) { + if ($chunk->type == 'copy' && $chunk->orig === array(' ')) { + $current->orig = array_merge((array) $current->orig, (array) $chunk->orig); + $current->closing = array_merge((array) $current->closing, (array) $chunk->closing); + } + else { + $processed[] = $current; + $current = $chunk; + } + } + $processed[] = $current; + + // Initial setup + $edits = $processed; + $processed = array(); + $current = array_shift($edits); + + // Second, merge equivalent chunks into each other. + while ($chunk = array_shift($edits)) { + if ($current->type == $chunk->type) { + $current->orig = array_merge((array) $current->orig, (array) $chunk->orig); + $current->closing = array_merge((array) $current->closing, (array) $chunk->closing); + } + else { + $processed[] = $current; + $current = $chunk; + } + } + $processed[] = $current; + + return $processed; + } +}