diff options
Diffstat (limited to 'wp-includes/cache.php')
| -rw-r--r-- | wp-includes/cache.php | 585 |
1 files changed, 285 insertions, 300 deletions
diff --git a/wp-includes/cache.php b/wp-includes/cache.php index 338f20b..9736da4 100644 --- a/wp-includes/cache.php +++ b/wp-includes/cache.php @@ -1,83 +1,204 @@ <?php +/** + * Object Cache API + * + * @package WordPress + * @subpackage Cache + */ + +/** + * wp_cache_add() - Adds data to the cache, if the cache key doesn't aleady exist + * + * @since 2.0 + * @uses $wp_object_cache Object Cache Class + * @see WP_Object_Cache::add() + * + * @param int|string $key The cache ID to use for retrieval later + * @param mixed $data The data to add to the cache store + * @param string $flag The group to add the cache to + * @param int $expire When the cache data should be expired + * @return unknown + */ function wp_cache_add($key, $data, $flag = '', $expire = 0) { global $wp_object_cache; - $data = unserialize(serialize($data)); return $wp_object_cache->add($key, $data, $flag, $expire); } +/** + * wp_cache_close() - Closes the cache + * + * This function has ceased to do anything since WordPress 2.5. + * The functionality was removed along with the rest of the + * persistant cache. + * + * @since 2.0 + * + * @return bool Always returns True + */ function wp_cache_close() { - global $wp_object_cache; - - if ( ! isset($wp_object_cache) ) - return; - return $wp_object_cache->save(); + return true; } +/** + * wp_cache_delete() - Removes the cache contents matching ID and flag + * + * @since 2.0 + * @uses $wp_object_cache Object Cache Class + * @see WP_Object_Cache::delete() + * + * @param int|string $id What the contents in the cache are called + * @param string $flag Where the cache contents are grouped + * @return bool True on successful removal, false on failure + */ function wp_cache_delete($id, $flag = '') { global $wp_object_cache; return $wp_object_cache->delete($id, $flag); } +/** + * wp_cache_flush() - Removes all cache items + * + * @since 2.0 + * @uses $wp_object_cache Object Cache Class + * @see WP_Object_Cache::flush() + * + * @return bool Always returns true + */ function wp_cache_flush() { global $wp_object_cache; return $wp_object_cache->flush(); } +/** + * wp_cache_get() - Retrieves the cache contents from the cache by ID and flag + * + * @since 2.0 + * @uses $wp_object_cache Object Cache Class + * @see WP_Object_Cache::get() + * + * @param int|string $id What the contents in the cache are called + * @param string $flag Where the cache contents are grouped + * @return bool|mixed False on failure to retrieve contents or the cache contents on success + */ function wp_cache_get($id, $flag = '') { global $wp_object_cache; return $wp_object_cache->get($id, $flag); } +/** + * wp_cache_init() - Sets up Object Cache Global and assigns it + * + * @since 2.0 + * @global WP_Object_Cache $wp_object_cache WordPress Object Cache + */ function wp_cache_init() { $GLOBALS['wp_object_cache'] =& new WP_Object_Cache(); } +/** + * wp_cache_replace() - Replaces the contents of the cache with new data + * + * @since 2.0 + * @uses $wp_object_cache Object Cache Class + * @see WP_Object_Cache::replace() + * + * @param int|string $id What to call the contents in the cache + * @param mixed $data The contents to store in the cache + * @param string $flag Where to group the cache contents + * @param int $expire When to expire the cache contents + * @return bool False if cache ID and group already exists, true on success + */ function wp_cache_replace($key, $data, $flag = '', $expire = 0) { global $wp_object_cache; - $data = unserialize(serialize($data)); return $wp_object_cache->replace($key, $data, $flag, $expire); } +/** + * wp_cache_set() - Saves the data to the cache + * + * @since 2.0 + * @uses $wp_object_cache Object Cache Class + * @see WP_Object_Cache::set() + * + * @param int|string $id What to call the contents in the cache + * @param mixed $data The contents to store in the cache + * @param string $flag Where to group the cache contents + * @param int $expire When to expire the cache contents + * @return bool False if cache ID and group already exists, true on success + */ function wp_cache_set($key, $data, $flag = '', $expire = 0) { global $wp_object_cache; - $data = unserialize(serialize($data)); return $wp_object_cache->set($key, $data, $flag, $expire); } -define('CACHE_SERIAL_HEADER', "<?php\n/*"); -define('CACHE_SERIAL_FOOTER', "*/\n?".">"); - +/** + * WordPress Object Cache + * + * The WordPress Object Cache is used to save on trips to the database. + * The Object Cache stores all of the cache data to memory and makes the + * cache contents available by using a key, which is used to name and + * later retrieve the cache contents. + * + * The Object Cache can be replaced by other caching mechanisms by placing + * files in the wp-content folder which is looked at in wp-settings. If + * that file exists, then this file will not be included. + * + * @package WordPress + * @subpackage Cache + * @since 2.0 + */ class WP_Object_Cache { - var $cache_dir; - var $cache_enabled = false; - var $expiration_time = 900; - var $flock_filename = 'wp_object_cache.lock'; - var $mutex; + + /** + * Holds the cached objects + * + * @var array + * @access private + * @since 2.0 + */ var $cache = array (); - var $dirty_objects = array (); + + /** + * Cache objects that do not exist in the cache + * + * @var array + * @access private + * @since 2.0 + */ var $non_existant_objects = array (); + + /** + * Object caches that are global + * + * @var array + * @access private + * @since 2.0 + */ var $global_groups = array ('users', 'userlogins', 'usermeta', 'site-options', 'site-lookup', 'blog-lookup', 'blog-details'); - var $non_persistent_groups = array('comment'); - var $blog_id; - var $cold_cache_hits = 0; - var $warm_cache_hits = 0; - var $cache_misses = 0; - var $secret = ''; - function acquire_lock() { - // Acquire a write lock. - $this->mutex = @fopen($this->cache_dir.$this->flock_filename, 'w'); - if ( false == $this->mutex) - return false; - flock($this->mutex, LOCK_EX); - return true; - } + /** + * The amount of times the cache data was already stored in the cache. + * + * @since 2.5 + * @access private + * @var int + */ + var $cache_hits = 0; + + /** + * Amount of times the cache did not have the request in cache + * + * @var int + * @access public + * @since 2.0 + */ + var $cache_misses = 0; function maybe_localize_group( $group ) { global $wpdb; @@ -95,6 +216,20 @@ class WP_Object_Cache { return "$prefix$group"; } + /** + * Adds data to the cache if it doesn't already exist. + * + * @uses WP_Object_Cache::get Checks to see if the cache already has data. + * @uses WP_Object_Cache::set Sets the data after the checking the cache contents existance. + * + * @since 2.0 + * + * @param int|string $id What to call the contents in the cache + * @param mixed $data The contents to store in the cache + * @param string $group Where to group the cache contents + * @param int $expire When to expire the cache contents + * @return bool False if cache ID and group already exists, true on success + */ function add($id, $data, $group = 'default', $expire = '') { if (empty ($group)) $group = 'default'; @@ -105,6 +240,23 @@ class WP_Object_Cache { return $this->set($id, $data, $group, $expire); } + /** + * Remove the contents of the cache ID in the group + * + * If the cache ID does not exist in the group and $force parameter + * is set to false, then nothing will happen. The $force parameter + * is set to false by default. + * + * On success the group and the id will be added to the + * $non_existant_objects property in the class. + * + * @since 2.0 + * + * @param int|string $id What the contents in the cache are called + * @param string $group Where the cache contents are grouped + * @param bool $force Optional. Whether to force the unsetting of the cache ID in the group + * @return bool False if the contents weren't deleted and true on success + */ function delete($id, $group = 'default', $force = false) { if (empty ($group)) $group = 'default'; @@ -115,172 +267,71 @@ class WP_Object_Cache { unset ($this->cache[$group][$id]); $this->non_existant_objects[$group][$id] = true; - $this->dirty_objects[$group][] = $id; return true; } + /** + * Clears the object cache of all data + * + * @since 2.0 + * + * @return bool Always returns true + */ function flush() { - if ( !$this->cache_enabled ) - return true; - - if ( ! $this->acquire_lock() ) - return false; - - $this->rm_cache_dir(); $this->cache = array (); - $this->dirty_objects = array (); - $this->non_existant_objects = array (); - - $this->release_lock(); return true; } - function get($id, $group = 'default', $count_hits = true) { + /** + * Retrieves the cache contents, if it exists + * + * The contents will be first attempted to be retrieved by searching + * by the ID in the cache group. If the cache is hit (success) then + * the contents are returned. + * + * On failure, the $non_existant_objects property is checked and if + * the cache group and ID exist in there the cache misses will not be + * incremented. If not in the nonexistant objects property, then the + * cache misses will be incremented and the cache group and ID will + * be added to the nonexistant objects. + * + * @since 2.0 + * + * @param int|string $id What the contents in the cache are called + * @param string $group Where the cache contents are grouped + * @return bool|mixed False on failure to retrieve contents or the cache contents on success + */ + function get($id, $group = 'default') { if (empty ($group)) $group = 'default'; $group = $this->maybe_localize_group( $group ); if (isset ($this->cache[$group][$id])) { - if ($count_hits) - $this->warm_cache_hits += 1; + $this->cache_hits += 1; return $this->cache[$group][$id]; } - if (isset ($this->non_existant_objects[$group][$id])) - return false; - - // If caching is not enabled, we have to fall back to pulling from the DB. - if (!$this->cache_enabled) { - if (!isset ($this->cache[$group])) - $this->load_group_from_db($group); - - if (isset ($this->cache[$group][$id])) { - $this->cold_cache_hits += 1; - return $this->cache[$group][$id]; - } - - $this->non_existant_objects[$group][$id] = true; - $this->cache_misses += 1; - return false; - } - - $cache_file = $this->cache_dir.$this->get_group_dir($group)."/".$this->hash($id).'.php'; - if (!file_exists($cache_file)) { - $this->non_existant_objects[$group][$id] = true; - $this->cache_misses += 1; + if ( isset ($this->non_existant_objects[$group][$id]) ) return false; - } - - // If the object has expired, remove it from the cache and return false to force - // a refresh. - $now = time(); - if ((filemtime($cache_file) + $this->expiration_time) <= $now) { - $this->cache_misses += 1; - $this->delete($id, $group, true); - return false; - } - - $this->cache[$group][$id] = unserialize(base64_decode(substr(@ file_get_contents($cache_file), strlen(CACHE_SERIAL_HEADER), -strlen(CACHE_SERIAL_FOOTER)))); - if (false === $this->cache[$group][$id]) - $this->cache[$group][$id] = ''; - - $this->cold_cache_hits += 1; - return $this->cache[$group][$id]; - } - - function get_group_dir($group) { - if (false !== array_search($group, $this->global_groups)) - return $group; - - return "{$this->blog_id}/$group"; - } - - function hash($data) { - if ( function_exists('hash_hmac') ) { - return hash_hmac('md5', $data, $this->secret); - } else { - return md5($data . $this->secret); - } - } - - function load_group_from_db($group) { - return; - global $wpdb; - - if ('category' == $group) { - $this->cache['category'] = array (); - if ($dogs = $wpdb->get_results("SELECT * FROM $wpdb->categories")) { - foreach ($dogs as $catt) - $this->cache['category'][$catt->cat_ID] = $catt; - } - } - - } - - function make_group_dir($group, $perms) { - $group_dir = $this->get_group_dir($group); - $make_dir = ''; - foreach (split('/', $group_dir) as $subdir) { - $make_dir .= "$subdir/"; - if (!file_exists($this->cache_dir.$make_dir)) { - if (! @ mkdir($this->cache_dir.$make_dir)) - break; - @ chmod($this->cache_dir.$make_dir, $perms); - } - - if (!file_exists($this->cache_dir.$make_dir."index.php")) { - $file_perms = $perms & 0000666; - @ touch($this->cache_dir.$make_dir."index.php"); - @ chmod($this->cache_dir.$make_dir."index.php", $file_perms); - } - } - return $this->cache_dir."$group_dir/"; - } - - function rm_cache_dir() { - $dir = $this->cache_dir; - $dir = rtrim($dir, DIRECTORY_SEPARATOR); - $top_dir = $dir; - $stack = array($dir); - $index = 0; - - while ($index < count($stack)) { - # Get indexed directory from stack - $dir = $stack[$index]; - - $dh = @ opendir($dir); - if (!$dh) - return false; - - while (($file = @ readdir($dh)) !== false) { - if ($file == '.' or $file == '..') - continue; - - if (@ is_dir($dir . DIRECTORY_SEPARATOR . $file)) - $stack[] = $dir . DIRECTORY_SEPARATOR . $file; - else if (@ is_file($dir . DIRECTORY_SEPARATOR . $file)) - @ unlink($dir . DIRECTORY_SEPARATOR . $file); - } - - $index++; - } - - $stack = array_reverse($stack); // Last added dirs are deepest - foreach($stack as $dir) { - if ( $dir != $top_dir) - @ rmdir($dir); - } - - } - - function release_lock() { - // Release write lock. - flock($this->mutex, LOCK_UN); - fclose($this->mutex); + $this->non_existant_objects[$group][$id] = true; + $this->cache_misses += 1; + return false; } + /** + * Replace the contents in the cache, if contents already exist + * + * @since 2.0 + * @see WP_Object_Cache::set() + * + * @param int|string $id What to call the contents in the cache + * @param mixed $data The contents to store in the cache + * @param string $group Where to group the cache contents + * @param int $expire When to expire the cache contents + * @return bool False if not exists, true if contents were replaced + */ function replace($id, $data, $group = 'default', $expire = '') { if (empty ($group)) $group = 'default'; @@ -291,164 +342,98 @@ class WP_Object_Cache { return $this->set($id, $data, $group, $expire); } + /** + * Sets the data contents into the cache + * + * The cache contents is grouped by the $group parameter followed + * by the $id. This allows for duplicate ids in unique groups. + * Therefore, naming of the group should be used with care and + * should follow normal function naming guidelines outside of + * core WordPress usage. + * + * The $expire parameter is not used, because the cache will + * automatically expire for each time a page is accessed and PHP + * finishes. The method is more for cache plugins which use files. + * + * @since 2.0 + * + * @param int|string $id What to call the contents in the cache + * @param mixed $data The contents to store in the cache + * @param string $group Where to group the cache contents + * @param int $expire Not Used + * @return bool Always returns true + */ function set($id, $data, $group = 'default', $expire = '') { if (empty ($group)) $group = 'default'; $group = $this->maybe_localize_group( $group ); - if (NULL == $data) + if (NULL === $data) $data = ''; $this->cache[$group][$id] = $data; - unset ($this->non_existant_objects[$group][$id]); - $this->dirty_objects[$group][] = $id; - - return true; - } - - function save() { - //$this->stats(); - - if (!$this->cache_enabled) - return true; - - if (empty ($this->dirty_objects)) - return true; - - // Give the new dirs the same perms as wp-content. - $stat = stat(ABSPATH.'wp-content'); - $dir_perms = $stat['mode'] & 0007777; // Get the permission bits. - $file_perms = $dir_perms & 0000666; // Remove execute bits for files. - // Make the base cache dir. - if (!file_exists($this->cache_dir)) { - if (! @ mkdir($this->cache_dir)) - return false; - @ chmod($this->cache_dir, $dir_perms); - } - - if (!file_exists($this->cache_dir."index.php")) { - @ touch($this->cache_dir."index.php"); - @ chmod($this->cache_dir."index.php", $file_perms); - } - - if ( ! $this->acquire_lock() ) - return false; - - // Loop over dirty objects and save them. - $errors = 0; - foreach ($this->dirty_objects as $group => $ids) { - $group_dir = $this->make_group_dir($group, $dir_perms); - - $ids = array_unique($ids); - foreach ($ids as $id) { - $cache_file = $group_dir.$this->hash($id).'.php'; - - // Remove the cache file if the key is not set. - if (!isset ($this->cache[$group][$id])) { - if (file_exists($cache_file)) - @ unlink($cache_file); - continue; - } - - $temp_file = tempnam($group_dir, 'tmp'); - $serial = CACHE_SERIAL_HEADER.base64_encode(serialize($this->cache[$group][$id])).CACHE_SERIAL_FOOTER; - $fd = @fopen($temp_file, 'w'); - if ( false === $fd ) { - $errors++; - continue; - } - fputs($fd, $serial); - fclose($fd); - if (!@ rename($temp_file, $cache_file)) { - if (!@ copy($temp_file, $cache_file)) - $errors++; - @ unlink($temp_file); - } - @ chmod($cache_file, $file_perms); - } - } - - $this->dirty_objects = array(); - - $this->release_lock(); - - if ( $errors ) - return false; + if(isset($this->non_existant_objects[$group][$id])) + unset ($this->non_existant_objects[$group][$id]); return true; } + /** + * Echos the stats of the caching. + * + * Gives the cache hits, and cache misses. Also prints every cached + * group, key and the data. + * + * @since 2.0 + */ function stats() { echo "<p>"; - echo "<strong>Cold Cache Hits:</strong> {$this->cold_cache_hits}<br/>"; - echo "<strong>Warm Cache Hits:</strong> {$this->warm_cache_hits}<br/>"; - echo "<strong>Cache Misses:</strong> {$this->cache_misses}<br/>"; + echo "<strong>Cache Hits:</strong> {$this->cache_hits}<br />"; + echo "<strong>Cache Misses:</strong> {$this->cache_misses}<br />"; echo "</p>"; foreach ($this->cache as $group => $cache) { echo "<p>"; - echo "<strong>Group:</strong> $group<br/>"; + echo "<strong>Group:</strong> $group<br />"; echo "<strong>Cache:</strong>"; echo "<pre>"; print_r($cache); echo "</pre>"; - if (isset ($this->dirty_objects[$group])) { - echo "<strong>Dirty Objects:</strong>"; - echo "<pre>"; - print_r(array_unique($this->dirty_objects[$group])); - echo "</pre>"; - echo "</p>"; - } } } + /** + * PHP4 constructor; Calls PHP 5 style constructor + * + * @since 2.0 + * + * @return WP_Object_Cache + */ function WP_Object_Cache() { return $this->__construct(); } + /** + * Sets up object properties; PHP 5 style constructor + * + * @since 2.0.8 + * @return null|WP_Object_Cache If cache is disabled, returns null. + */ function __construct() { - global $blog_id; - - register_shutdown_function(array(&$this, "__destruct")); - - if (defined('DISABLE_CACHE')) - return; - - if ( ! defined('ENABLE_CACHE') ) - return; - - // Disable the persistent cache if safe_mode is on. - if ( ini_get('safe_mode') && ! defined('ENABLE_CACHE') ) - return; - - if (defined('CACHE_PATH')) - $this->cache_dir = CACHE_PATH; - else - // Using the correct separator eliminates some cache flush errors on Windows - $this->cache_dir = ABSPATH.'wp-content'.DIRECTORY_SEPARATOR.'cache'.DIRECTORY_SEPARATOR; - - if (is_writable($this->cache_dir) && is_dir($this->cache_dir)) { - $this->cache_enabled = true; - } else { - if (is_writable(ABSPATH.'wp-content')) { - $this->cache_enabled = true; - } - } - - if (defined('CACHE_EXPIRATION_TIME')) - $this->expiration_time = CACHE_EXPIRATION_TIME; - - if ( defined('WP_SECRET') ) - $this->secret = WP_SECRET; - else - $this->secret = DB_PASSWORD . DB_USER . DB_NAME . DB_HOST . ABSPATH; - - $this->blog_id = $this->hash($blog_id); + register_shutdown_function(array(&$this, "__destruct")); /** @todo This should be moved to the PHP4 style constructor, PHP5 already calls __destruct() */ } + /** + * Will save the object cache before object is completely destroyed. + * + * Called upon object destruction, which should be when PHP ends. + * + * @since 2.0.8 + * + * @return bool True value. Won't be used by PHP + */ function __destruct() { - $this->save(); return true; } } |