<?php
+/**
+ * Object Cache API
+ *
+ * @link http://codex.wordpress.org/Function_Reference/WP_Cache
+ *
+ * @package WordPress
+ * @subpackage Cache
+ */
+
+/**
+ * Adds data to the cache, if the cache key doesn't aleady exist.
+ *
+ * @since 2.0.0
+ * @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;
return $wp_object_cache->add($key, $data, $flag, $expire);
}
+/**
+ * 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. This
+ * does not mean that plugins can't implement this function when they need to
+ * make sure that the cache is cleaned up after WordPress no longer needs it.
+ *
+ * @since 2.0.0
+ *
+ * @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;
}
+/**
+ * Removes the cache contents matching ID and flag.
+ *
+ * @since 2.0.0
+ * @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);
}
+/**
+ * Removes all cache items.
+ *
+ * @since 2.0.0
+ * @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();
}
+/**
+ * Retrieves the cache contents from the cache by ID and flag.
+ *
+ * @since 2.0.0
+ * @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);
}
+/**
+ * Sets up Object Cache Global and assigns it.
+ *
+ * @since 2.0.0
+ * @global WP_Object_Cache $wp_object_cache WordPress Object Cache
+ */
function wp_cache_init() {
$GLOBALS['wp_object_cache'] =& new WP_Object_Cache();
}
+/**
+ * Replaces the contents of the cache with new data.
+ *
+ * @since 2.0.0
+ * @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;
return $wp_object_cache->replace($key, $data, $flag, $expire);
}
+/**
+ * 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;
return $wp_object_cache->set($key, $data, $flag, $expire);
}
-define('CACHE_SERIAL_HEADER', "<?php\n/*");
-define('CACHE_SERIAL_FOOTER', "*/\n?".">");
+/**
+ * Adds a group or set of groups to the list of global groups.
+ *
+ * @since 2.6.0
+ *
+ * @param string|array $groups A group or an array of groups to add
+ */
+function wp_cache_add_global_groups( $groups ) {
+ // Default cache doesn't persist so nothing to do here.
+ return;
+}
+
+/**
+ * Adds a group or set of groups to the list of non-persistent groups.
+ *
+ * @since 2.6.0
+ *
+ * @param string|array $groups A group or an array of groups to add
+ */
+function wp_cache_add_non_persistent_groups( $groups ) {
+ // Default cache doesn't persist so nothing to do here.
+ return;
+}
+/**
+ * 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 2.0.0
+ */
var $cache = array ();
- var $dirty_objects = array ();
+
+ /**
+ * Cache objects that do not exist in the cache
+ *
+ * @var array
+ * @access private
+ * @since 2.0.0
+ */
var $non_existant_objects = array ();
- var $global_groups = array ('users', 'userlogins', 'usermeta');
- 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 2.5.0
+ * @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 2.0.0
+ */
+ var $cache_misses = 0;
+ /**
+ * 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 2.0.0
+ *
+ * @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';
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 2.0.0
+ *
+ * @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))
$group = 'default';
unset ($this->cache[$group][$id]);
$this->non_existant_objects[$group][$id] = true;
- $this->dirty_objects[$group][] = $id;
return true;
}
+ /**
+ * Clears the object cache of all data
+ *
+ * @since 2.0.0
+ *
+ * @return bool Always returns true
+ */
function flush() {
- if ( !$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 2.0.0
+ *
+ * @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))
$group = 'default';
if (isset ($this->cache[$group][$id])) {
- if ($count_hits)
- $this->warm_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;
+ $this->cache_hits += 1;
+ if ( is_object($this->cache[$group][$id]) )
+ return wp_clone($this->cache[$group][$id]);
+ else
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;
- 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, $group, true);
+ if ( isset ($this->non_existant_objects[$group][$id]) )
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) {
- 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] = $catt;
-
- foreach ($this->cache['category'] as $catt) {
- $curcat = $catt->cat_ID;
- $fullpath = '/'.$this->cache['category'][$catt->cat_ID]->category_nicename;
- while ($this->cache['category'][$curcat]->category_parent != 0) {
- $curcat = $this->cache['category'][$curcat]->category_parent;
- $fullpath = '/'.$this->cache['category'][$curcat]->category_nicename.$fullpath;
- }
- $this->cache['category'][$catt->cat_ID]->fullpath = $fullpath;
- }
- }
- } else
- if ('options' == $group) {
- $wpdb->hide_errors();
- if (!$options = $wpdb->get_results("SELECT option_name, option_value FROM $wpdb->options WHERE autoload = 'yes'")) {
- $options = $wpdb->get_results("SELECT option_name, option_value FROM $wpdb->options");
- }
- $wpdb->show_errors();
-
- if ( ! $options )
- return;
-
- foreach ($options as $option) {
- $this->cache['options'][$option->option_name] = $option->option_value;
- }
- }
- }
-
- function make_group_dir($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 2.0.0
+ * @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';
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 2.0.0
+ *
+ * @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';
- 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 (!$this->cache_enabled)
- return true;
+ if ( is_object($data) )
+ $data = wp_clone($data);
- 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, $cache_file))
- @ unlink($temp_file);
- else
- $errors++;
- }
- @ chmod($cache_file, $file_perms);
- }
- }
-
- $this->dirty_objects = array();
+ $this->cache[$group][$id] = $data;
- $this->release_lock();
-
- if ( $errors )
- return false;
+ if(isset($this->non_existant_objects[$group][$id]))
+ unset ($this->non_existant_objects[$group][$id]);
return true;
}
+ /**
+ * Echos the stats of the caching.
+ *
+ * Gives the cache hits, and cache misses. Also prints every cached group,
+ * key and the data.
+ *
+ * @since 2.0.0
+ */
function stats() {
echo "<p>";
- echo "<strong>Cold Cache Hits:</strong> {$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 2.0.0
+ *
+ * @return WP_Object_Cache
+ */
function WP_Object_Cache() {
return $this->__construct();
}
-
- function __construct() {
- global $blog_id;
+ /**
+ * Sets up object properties; PHP 5 style constructor
+ *
+ * @since 2.0.8
+ * @return null|WP_Object_Cache If cache is disabled, returns null.
+ */
+ function __construct() {
+ /**
+ * @todo This should be moved to the PHP4 style constructor, PHP5
+ * already calls __destruct()
+ */
register_shutdown_function(array(&$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);
}
+ /**
+ * 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;
+ return true;
}
}
?>
scripts.mit.edu / autoinstalls / wordpress.git / blobdiff