<?php // File: benchmark_drupal_static.php Version: 2010-07-16 23:00

// This drupal_static_new() is from post 10 from http://drupal.org/node/768090
function &drupal_static_new($name, $default_value = NULL, $reset = FALSE) {
  static $data = array(), $default = array();
  // First check if dealing with a previously defined static variable.
  if (isset($data[$name]) || array_key_exists($name, $data)) {
    // Non-NULL $name and both $data[$name] and $default[$name] statics exist.
    if ($reset) {
      // Reset pre-existing static variable to its default value.
      $data[$name] = $default[$name];
    }
    return $data[$name];
  }
  // Neither $data[$name] nor $default[$name] static variables exist.
  if (isset($name)) {
    if ($reset) {
      // Reset was called before a default is set and yet a variable must be
      // returned.
      return $data;
    }
    // First call with new non-NULL $name. Initialize a new static variable.
    $default[$name] = $data[$name] = $default_value;
    return $data[$name];
  }
  // Reset all: ($name == NULL). This needs to be done one at a time so that
  // references returned by earlier invocations of drupal_static() also get
  // reset.
  foreach ($default as $name => $value) {
    $data[$name] = $value;
  }
  // As the function returns a reference, the return should always be a
  // variable.
  return $data;
}

// This drupal_static_old() is from drupal-7.0-alpha6 (7.0 HEAD as of 2010-07-16)
function &drupal_static_old($name, $default_value = NULL, $reset = FALSE) {
  static $data = array(), $default = array();
  if (!isset($name)) {
    // All variables are reset. This needs to be done one at a time so that
    // references returned by earlier invocations of drupal_static() also get
    // reset.
    foreach ($default as $name => $value) {
      $data[$name] = $value;
    }
    // As the function returns a reference, the return should always be a
    // variable.
    return $data;
  }
  if ($reset) {
    // The reset means the default is loaded.
    if (array_key_exists($name, $default)) {
      $data[$name] = $default[$name];
    }
    else {
      // Reset was called before a default is set and yet a variable must be
      // returned.
      return $data;
    }
  }
  elseif (!array_key_exists($name, $data)) {
    // Store the default value internally and also copy it to the reference to
    // be returned.
    $default[$name] = $data[$name] = $default_value;
  }
  return $data[$name];
}

function test_old($nvars, $nreps) {
    $varnames = array();
    // create $nvars new static variables
    for ($j = 0; $j < $nvars; $j++) {
        $varnames[$j] = sprintf("%s_%03d", __FUNCTION__, $j);
        $var[$j] =& drupal_static_old($varnames[$j]);
        $var[$j] = $j;
    }
    // main loop. recall all $nvars variables, $nreps times
    $t0 = microtime(TRUE); // mark start time
    for ($i = 0; $i < $nreps; $i++) {
        for ($j = 0; $j < $nvars; $j++) {
            $var[$j] =& drupal_static_old($varnames[$j]);
        }
    }
    $t_elapsed = microtime(TRUE) - $t0; // elapsed seconds
    $t_microsec = $t_elapsed * 1000000 / ($nvars * $nreps);
    return $t_microsec;// return microseconds per call
}

function test_new($nvars, $nreps) {
    $varnames = array();
    // create $nvars new static variables
    for ($j = 0; $j < $nvars; $j++) {
        $varnames[$j] = sprintf("%s_%03d", __FUNCTION__, $j);
        $var[$j] =& drupal_static_new($varnames[$j]);
        $var[$j] = $j;
    }
    // main loop. recall all $nvars variables, $nreps times
    $t0 = microtime(TRUE);              // mark start time
    for ($i = 0; $i < $nreps; $i++) {
        for ($j = 0; $j < $nvars; $j++) {
            $var[$j] =& drupal_static_new($varnames[$j]);
        }
    }
    $t_elapsed = microtime(TRUE) - $t0; // elapsed seconds
    $t_microsec = $t_elapsed * 1000000 / ($nvars * $nreps);
    return $t_microsec;                 // return microseconds per call
}

function test($nvars, $nreps) {
    // $nvars is the number of static variables to be created and recalled
    // $nreps is number of times all $nvars will be called during measurement
    // The total number of drupal_static calls measured is $nvars * $nreps.
    static $testnum = 0;                // current test number
    $msg = sprintf("%2d: ", ++$testnum);// assemble output string
    $ncalls = $nvars * $nreps;          // number of calls made
    $msg .= sprintf("nVars=%4d nCalls=%6d ", $nvars, $ncalls);
    $t_old = test_old($nvars, $nreps);
    $msg .= sprintf("t_old=%5.1fus ", $t_old);
    $t_new = test_new($nvars, $nreps);
    $msg .= sprintf("t_new=%5.1fus ", $t_new);
    $gain = 100.0 * ($t_old - $t_new) / $t_old;
    $speedX = $t_old / $t_new;
    $msg .= sprintf("gain=%3.1f%% speed=%5.2fx\n", $gain, $speedX);
    echo($msg);
}
// Ok run a series of tests with 100000 calls each. (This value determined by
// trial and error to take about a second to rum on a Athlon64 3700+ WinXP box.)
// Note that multiple tests should be run with increasing values of $nvars,
// because drupal_static "remembers" all values stored from the previous run.
//   nVar  nReps
test(   1,100000);
test(   5, 20000);
test(  10, 10000);
test(  50,  2000);
test( 100,  1000);
test( 500,   200);
test(1000,   100);
?>