Index: includes/common.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/common.inc,v
retrieving revision 1.593
diff -u -p -r1.593 common.inc
--- includes/common.inc	30 Nov 2006 08:13:31 -0000	1.593
+++ includes/common.inc	30 Nov 2006 15:53:24 -0000
@@ -1259,6 +1259,7 @@ function drupal_page_footer() {
   if (variable_get('cache', 0)) {
     page_set_cache();
   }
+  drupal_lookup_path('cache');
 
   module_invoke_all('exit');
 }
Index: includes/path.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/path.inc,v
retrieving revision 1.11
diff -u -p -r1.11 path.inc
--- includes/path.inc	26 Nov 2006 01:55:37 -0000	1.11
+++ includes/path.inc	30 Nov 2006 15:53:24 -0000
@@ -32,6 +32,7 @@ function drupal_init_path() {
  *   - wipe: delete the alias cache.
  *   - alias: return an alias for a given Drupal system path (if one exists).
  *   - source: return the Drupal system URL for a path alias (if one exists).
+ *   - cache: (internal use only) save the maps into the cache_path table.
  * @param $path
  *   The path to investigate for corresponding aliases or system URLs.
  *
@@ -41,46 +42,88 @@ function drupal_init_path() {
  */
 function drupal_lookup_path($action, $path = '') {
   // $map keys are Drupal paths and the values are the corresponding aliases
-  static $map = array(), $no_src = array();
-  static $count = NULL;
+  static
+    $map, $no_src,
+    $map_dirty = FALSE, $no_src_dirty = FALSE,
+    $count = NULL, $expire = 0;
+  global $base_root;
+
 
   // Use $count to avoid looking up paths in subsequent calls if there simply are no aliases
   if ($count === NULL) {
     $count = db_result(db_query('SELECT COUNT(pid) FROM {url_alias}'));
   }
 
-  if ($action == 'wipe') {
-    $map = array();
-    $no_src = array();
-  }
-  elseif ($count > 0 && $path != '') {
-    if ($action == 'alias') {
-      if (isset($map[$path]) || array_key_exists($path, $map)) {
-        return $map[$path];
-      }
-      $alias = db_result(db_query("SELECT dst FROM {url_alias} WHERE src = '%s'", $path));
-      $map[$path] = $alias;
-      return $alias;
+  if (!isset($map)) {
+    $cache = cache_get('map_'. $base_root . request_uri(), 'cache_path');
+    if ($cache) {
+      $map = unserialize($cache->data);
+      $expire = $cache->expire;
     }
-    // Check $no_src for this $path in case we've already determined that there
-    // isn't a path that has this alias
-    elseif ($action == 'source' && !isset($no_src[$path])) {
-      // Look for the value $path within the cached $map
-      if (!$src = array_search($path, $map)) {
-        if ($src = db_result(db_query("SELECT src FROM {url_alias} WHERE dst = '%s'", $path))) {
-          $map[$src] = $path;
+    else {
+      $map = array();
+    }
+
+    $cache = cache_get('no_src_'. $base_root . request_uri(), 'cache_path');
+    if ($cache) {
+      $no_src = unserialize($cache->data);
+      $expire = $cache->expire;
+    }
+    else {
+      $no_src = array();
+    }
+  }
+  switch ($action) {
+    case 'alias':
+      if ($count > 0 && $path) {
+        if (isset($map[$path])) {
+          return $map[$path];
         }
-        else {
-          // We can't record anything into $map because we do not have a valid
-          // index and there is no need because we have not learned anything
-          // about any Drupal path. Thus cache to $no_src.
-          $no_src[$path] = TRUE;
+        if (!$alias = db_result(db_query("SELECT dst FROM {url_alias} WHERE src = '%s'", $path))) {
+          $alias = FALSE;
         }
+        $map[$path] = $alias;
+        $map_dirty = TRUE;
+        return $alias;
       }
-      return $src;
-    }
+      break;
+    case 'source':
+      // Check $no_src for this $path in case we've already determined that there
+      // isn't a path that has this alias
+      if ($count > 0 && $path && !isset($no_src[$path])) {
+        if (!$src = array_search($path, $map)) {
+          if ($src = db_result(db_query("SELECT src FROM {url_alias} WHERE dst = '%s'", $path))) {
+            $map[$src] = $path;
+            $map_dirty = TRUE;
+          }
+          else {
+            // We can't record anything into $map because we do not have a valid
+            // index and there is no need because we have not learned anything
+            // about any Drupal path. Thus cache to $no_src.
+            $no_src[$path] = TRUE;
+            $no_src_dirty = TRUE;
+            return FALSE;
+          }
+        }
+        return $src;
+      }
+      break;
+    case 'wipe':
+      $map = array();
+      $no_src = array();
+      break;
+    case 'cache':
+      if (!$expire) {
+        $expire = time() + (60 * 60 * 24);
+      }
+      if ($map_dirty) {
+        cache_set('map_'. $base_root . request_uri(), 'cache_path', serialize($map), $expire);
+      }
+      if ($no_src_dirty) {
+        cache_set('no_src_' . $base_root . request_uri(), 'cache_path', serialize($no_src), $expire);
+      }
+      break;
   }
-
   return FALSE;
 }
 
Index: modules/path/path.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/path/path.module,v
retrieving revision 1.103
diff -u -p -r1.103 path.module
--- modules/path/path.module	26 Nov 2006 02:20:01 -0000	1.103
+++ modules/path/path.module	30 Nov 2006 15:53:24 -0000
@@ -130,11 +130,9 @@ function path_admin_delete($pid = 0) {
 function path_set_alias($path = NULL, $alias = NULL, $pid = NULL) {
   if ($path && !$alias) {
     db_query("DELETE FROM {url_alias} WHERE src = '%s'", $path);
-    drupal_clear_path_cache();
   }
   else if (!$path && $alias) {
     db_query("DELETE FROM {url_alias} WHERE dst = '%s'", $alias);
-    drupal_clear_path_cache();
   }
   else if ($path && $alias) {
     $path = urldecode($path);
@@ -145,7 +143,6 @@ function path_set_alias($path = NULL, $a
     // We have an insert:
     if ($path_count == 0 && $alias_count == 0) {
       db_query("INSERT INTO {url_alias} (src, dst) VALUES ('%s', '%s')", $path, $alias);
-      drupal_clear_path_cache();
     }
     else if ($path_count >= 1 && $alias_count == 0) {
       if ($pid) {
@@ -154,11 +151,9 @@ function path_set_alias($path = NULL, $a
       else {
         db_query("INSERT INTO {url_alias} (src, dst) VALUES ('%s', '%s')", $path, $alias);
       }
-      drupal_clear_path_cache();
     }
     else if ($path_count == 0 && $alias_count == 1) {
       db_query("UPDATE {url_alias} SET src = '%s' WHERE dst = '%s'", $path, $alias);
-      drupal_clear_path_cache();
     }
     else if ($path_count == 1 && $alias_count == 1) {
       // This will delete the path that alias was originally pointing to:
@@ -167,6 +162,10 @@ function path_set_alias($path = NULL, $a
       path_set_alias($path, $alias);
     }
   }
+
+  // Clear the static and the database cache.
+  drupal_clear_path_cache();
+  cache_clear_all(NULL, 'cache_path');
 }
 
 /**
Index: modules/system/system.install
===================================================================
RCS file: /cvs/drupal/drupal/modules/system/system.install,v
retrieving revision 1.50
diff -u -p -r1.50 system.install
--- modules/system/system.install	30 Nov 2006 02:19:38 -0000	1.50
+++ modules/system/system.install	30 Nov 2006 15:53:25 -0000
@@ -197,6 +197,15 @@ function system_install() {
         PRIMARY KEY (cid),
         INDEX expire (expire)
       ) /*!40100 DEFAULT CHARACTER SET UTF8 */ ");
+      db_query("CREATE TABLE {cache_path} (
+        cid varchar(255) BINARY NOT NULL default '',
+        data longblob,
+        expire int NOT NULL default '0',
+        created int NOT NULL default '0',
+        headers text,
+        PRIMARY KEY (cid),
+        INDEX expire (expire)
+      ) /*!40100 DEFAULT CHARACTER SET UTF8 */ ");
 
       db_query("CREATE TABLE {comments} (
         cid int NOT NULL auto_increment,
@@ -658,10 +667,19 @@ function system_install() {
         headers text,
         PRIMARY KEY (cid)
       )");
+      db_query("CREATE TABLE {cache_path} (
+        cid varchar(255) NOT NULL default '',
+        data bytea,
+        expire int NOT NULL default '0',
+        created int NOT NULL default '0',
+        headers text,
+        PRIMARY KEY (cid)
+      )");
       db_query("CREATE INDEX {cache}_expire_idx ON {cache} (expire)");
       db_query("CREATE INDEX {cache_filter}_expire_idx ON {cache_filter} (expire)");
       db_query("CREATE INDEX {cache_menu}_expire_idx ON {cache_menu} (expire)");
       db_query("CREATE INDEX {cache_page}_expire_idx ON {cache_page} (expire)");
+      db_query("CREATE INDEX {cache_path}_expire_idx ON {cache_page} (expire)");
 
       db_query("CREATE TABLE {comments} (
         cid serial,
@@ -3363,6 +3381,45 @@ function system_update_1016() {
 }
 
 /**
+ * Add table for caching URL aliases
+ */
+function system_update_1017() {
+  $ret = array();
+
+  switch ($GLOBALS['db_type']) {
+    case 'mysqli':
+    case 'mysql':
+      // Create node_type table
+      $ret[] = update_sql("CREATE TABLE {cache_path} (
+        cid varchar(255) BINARY NOT NULL default '',
+        data longblob,
+        expire int NOT NULL default '0',
+        created int NOT NULL default '0',
+        headers text,
+        PRIMARY KEY (cid),
+        INDEX expire (expire)
+      ) /*!40100 DEFAULT CHARACTER SET UTF8 */;");
+      break;
+
+    case 'pgsql':
+      // add new unsigned types for pgsql
+      $ret[] = update_sql("CREATE TABLE {cache_path} (
+        cid varchar(255) NOT NULL default '',
+        data bytea,
+        expire int NOT NULL default '0',
+        created int NOT NULL default '0',
+        headers text,
+        PRIMARY KEY (cid)
+      )");
+      $ret[] = update_sql("CREATE INDEX {cache_path}_expire_idx ON {cache_page} (expire)");
+
+      break;
+  }
+
+  return $ret;
+}
+
+/**
  * @} End of "defgroup updates-4.7-to-5.0"
  */