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Erick Hitter authoredErick Hitter authored
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object-cache.php 20.41 KiB
<?php
/**
* Adds a value to cache.
*
* If the specified key already exists, the value is not stored and the function
* returns false.
*
* @param string $key The key under which to store the value.
* @param mixed $value The value to store.
* @param string $group The group value appended to the $key.
* @param int $expiration The expiration time, defaults to 0.
*
* @return bool Returns TRUE on success or FALSE on failure.
*/
function wp_cache_add( $key, $value, $group = '', $expiration = 0 ) {
global $wp_object_cache;
return $wp_object_cache->add( $key, $value, $group, $expiration );
}
/**
* Closes the cache.
*
* This function has ceased to do anything since WordPress 2.5. The
* functionality was removed along with the rest of the persistent 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() {
return true;
}
/**
* Decrement a numeric item's value.
*
* @param string $key The key under which to store the value.
* @param int $offset The amount by which to decrement the item's value.
* @param string $group The group value appended to the $key.
*
* @return int|bool Returns item's new value on success or FALSE on failure.
*/
function wp_cache_decr( $key, $offset = 1, $group = '' ) {
global $wp_object_cache;
return $wp_object_cache->decrement( $key, $offset, $group );
}
/**
* Remove the item from the cache.
*
* @param string $key The key under which to store the value.
* @param string $group The group value appended to the $key.
* @param int $time The amount of time the server will wait to delete the item in seconds.
*
* @return bool Returns TRUE on success or FALSE on failure.
*/
function wp_cache_delete( $key, $group = '', $time = 0 ) {
global $wp_object_cache;
return $wp_object_cache->delete( $key, $group, $time );
}
/**
* Invalidate all items in the cache.
*
* @param int $delay Number of seconds to wait before invalidating the items.
*
* @return bool Returns TRUE on success or FALSE on failure.
*/
function wp_cache_flush( $delay = 0 ) {
global $wp_object_cache;
return $wp_object_cache->flush( $delay );
}
/**
* Retrieve object from cache.
*
* Gets an object from cache based on $key and $group.
*
* @param string $key The key under which to store the value.
* @param string $group The group value appended to the $key.
*
* @return bool|mixed Cached object value.
*/
function wp_cache_get( $key, $group = '' ) {
global $wp_object_cache;
return $wp_object_cache->get( $key, $group );
}
/**
* Increment a numeric item's value.
*
* @param string $key The key under which to store the value.
* @param int $offset The amount by which to increment the item's value.
* @param string $group The group value appended to the $key.
*
* @return int|bool Returns item's new value on success or FALSE on failure.
*/
function wp_cache_incr( $key, $offset = 1, $group = '' ) {
global $wp_object_cache;
return $wp_object_cache->increment( $key, $offset, $group );
}
/**
* Sets up Object Cache Global and assigns it.
*
* @global WP_Object_Cache $wp_object_cache WordPress Object Cache
* @return void
*/
function wp_cache_init() {
global $wp_object_cache;
$wp_object_cache = new WP_Object_Cache();
}
/**
* Replaces a value in cache.
*
* This method is similar to "add"; however, is does not successfully set a value if
* the object's key is not already set in cache.
*
* @param string $key The key under which to store the value.
* @param mixed $value The value to store.
* @param string $group The group value appended to the $key.
* @param int $expiration The expiration time, defaults to 0.
*
* @return bool Returns TRUE on success or FALSE on failure.
*/
function wp_cache_replace( $key, $value, $group = '', $expiration = 0 ) {
global $wp_object_cache;
return $wp_object_cache->replace( $key, $value, $group, $expiration );
}
/**
* Sets a value in cache.
*
* The value is set whether or not this key already exists in Redis.
*
* @param string $key The key under which to store the value.
* @param mixed $value The value to store.
* @param string $group The group value appended to the $key.
* @param int $expiration The expiration time, defaults to 0.
*
* @return bool Returns TRUE on success or FALSE on failure.
*/
function wp_cache_set( $key, $value, $group = '', $expiration = 0 ) {
global $wp_object_cache;
return $wp_object_cache->set( $key, $value, $group, $expiration );
}
/**
* Switch the interal blog id.
*
* This changes the blog id used to create keys in blog specific groups.
*
* @param int $_blog_id Blog ID
* @return bool
*/
function wp_cache_switch_to_blog( $_blog_id ) {
global $wp_object_cache;
return $wp_object_cache->switch_to_blog( $_blog_id );
}
/**
* Adds a group or set of groups to the list of Redis groups.
*
* @param string|array $groups A group or an array of groups to add.
*
* @return void
*/
function wp_cache_add_global_groups( $groups ) {
global $wp_object_cache;
$wp_object_cache->add_global_groups( $groups );
}
/**
* Adds a group or set of groups to the list of non-Redis groups.
*
* @param string|array $groups A group or an array of groups to add.
*
* @return void
*/
function wp_cache_add_non_persistent_groups( $groups ) {
global $wp_object_cache;
$wp_object_cache->add_non_persistent_groups( $groups );
}
class WP_Object_Cache {
/**
* Holds the Redis client.
*
* @var Predis\Client
*/
public $redis;
/**
* Holds the non-Redis objects.
*
* @var array
*/
public $cache = array();
/**
* List of global groups.
*
* @var array
*/
public $global_groups = array( 'users', 'userlogins', 'usermeta', 'site-options', 'site-lookup', 'blog-lookup', 'blog-details', 'rss' );
/**
* List of groups not saved to Redis.
*
* @var array
*/
public $no_redis_groups = array( 'comment', 'counts' );
/**
* Prefix used for global groups.
*
* @var string
*/
public $global_prefix = '';
/**
* Prefix used for non-global groups.
*
* @var string
*/
public $blog_prefix = '';
/**
* Track how many requests were found in cache
*
* @var int
*/
public $cache_hits = 0;
/**
* Track how may requests were not cached
*
* @var int
*/
public $cache_misses = 0;
/**
* Instantiate the Redis class.
*
* Instantiates the Redis class.
*
* @param null $persistent_id To create an instance that persists between requests, use persistent_id to specify a unique ID for the instance.
*/
public function __construct() {
require_once 'predis/autoload.php';
$redis = array(
'host' => '127.0.0.1',
'port' => 6379,
);
if ( defined( 'WP_REDIS_BACKEND_HOST' ) && WP_REDIS_BACKEND_HOST ) {
$redis['host'] = WP_REDIS_BACKEND_HOST;
}
if ( defined( 'WP_REDIS_BACKEND_PORT' ) && WP_REDIS_BACKEND_PORT ) {
$redis['port'] = WP_REDIS_BACKEND_PORT;
}
if ( defined( 'WP_REDIS_BACKEND_DB' ) && WP_REDIS_BACKEND_DB ) {
$redis['database'] = WP_REDIS_BACKEND_DB;
}
$this->redis = new Predis\Client( $redis );
unset( $redis );
global $blog_id, $table_prefix;
/**
* This approach is borrowed from Sivel and Boren. Use the salt for easy cache invalidation and for
* multi single WP installs on the same server.
*/
if ( ! defined( 'WP_CACHE_KEY_SALT' ) ) {
define( 'WP_CACHE_KEY_SALT', '' );
}
// Assign global and blog prefixes for use with keys
$this->global_prefix = ( is_multisite() || defined( 'CUSTOM_USER_TABLE' ) && defined( 'CUSTOM_USER_META_TABLE' ) ) ? '' : $table_prefix;
$this->blog_prefix = ( is_multisite() ? $blog_id : $table_prefix ) . ':';
}
/**
* Adds a value to cache.
*
* If the specified key already exists, the value is not stored and the function
* returns false.
*
* @param string $key The key under which to store the value.
* @param mixed $value The value to store.
* @param string $group The group value appended to the $key.
* @param int $expiration The expiration time, defaults to 0.
* @return bool Returns TRUE on success or FALSE on failure.
*/
public function add( $key, $value, $group = 'default', $expiration = 0 ) {
return $this->add_or_replace( true, $key, $value, $group, $expiration );
}
/**
* Replace a value in the cache.
*
* If the specified key doesn't exist, the value is not stored and the function
* returns false.
*
* @param string $key The key under which to store the value.
* @param mixed $value The value to store.
* @param string $group The group value appended to the $key.
* @param int $expiration The expiration time, defaults to 0.
* @return bool Returns TRUE on success or FALSE on failure.
*/
public function replace( $key, $value, $group = 'default', $expiration = 0 ) {
return $this->add_or_replace( false, $key, $value, $group, $expiration );
}
/**
* Add or replace a value in the cache.
*
* Add does not set the value if the key exists; replace does not replace if the value doesn't exist.
*
* @param bool $add True if should only add if value doesn't exist, false to only add when value already exists
* @param string $key The key under which to store the value.
* @param mixed $value The value to store.
* @param string $group The group value appended to the $key.
* @param int $expiration The expiration time, defaults to 0.
* @return bool Returns TRUE on success or FALSE on failure.
*/
protected function add_or_replace( $add, $key, $value, $group = 'default', $expiration = 0 ) {
$derived_key = $this->build_key( $key, $group );
// If group is a non-Redis group, save to internal cache, not Redis
if ( in_array( $group, $this->no_redis_groups ) ) {
// Check if conditions are right to continue
if (
( $add && isset( $this->cache[$derived_key] ) ) ||
( ! $add && ! isset( $this->cache[$derived_key] ) )
) {
return false;
}
$this->add_to_internal_cache( $derived_key, $value );
return true;
}
// Check if conditions are right to continue
if (
( $add && $this->redis->exists( $derived_key ) ) ||
( ! $add && ! $this->redis->exists( $derived_key ) )
) {
return false;
}
// Save to Redis
$expiration = absint( $expiration );
if ( $expiration ) {
$result = $this->parse_predis_response( $this->redis->setex( $derived_key, $expiration, $this->prepare_value_for_redis( $value ) ) );
} else {
$result = $this->parse_predis_response( $this->redis->set( $derived_key, $this->prepare_value_for_redis( $value ) ) );
}
return $result;
}
/**
* Remove the item from the cache.
*
* @param string $key The key under which to store the value.
* @param string $group The group value appended to the $key.
* @return bool Returns TRUE on success or FALSE on failure.
*/
public function delete( $key, $group = 'default' ) {
$derived_key = $this->build_key( $key, $group );
// Remove from no_mc_groups array
if ( in_array( $group, $this->no_redis_groups ) ) {
if ( isset( $this->cache[$derived_key] ) ) {
unset( $this->cache[$derived_key] );
return true;
}
}
$result = $this->parse_predis_response( $this->redis->del( $derived_key ) );
unset( $this->cache[$derived_key] );
return $result;
}
/**
* Invalidate all items in the cache.
*
* @param int $delay Number of seconds to wait before invalidating the items.
*
* @return bool Returns TRUE on success or FALSE on failure.
*/
public function flush( $delay = 0 ) {
$delay = absint( $delay );
if ( $delay ) {
sleep( $delay );
}
$this->cache = array();
$result = $this->parse_predis_response( $this->redis->flushdb() );
return $result;
}
/**
* Retrieve object from cache.
*
* Gets an object from cache based on $key and $group.
*
* @param string $key The key under which to store the value.
* @param string $group The group value appended to the $key.
*
* @return bool|mixed Cached object value.
*/
public function get( $key, $group = 'default' ) {
$derived_key = $this->build_key( $key, $group );
if ( in_array( $group, $this->no_redis_groups ) ) {
if ( isset( $this->cache[$derived_key] ) ) {
$this->cache_hits++;
return is_object( $this->cache[$derived_key] ) ? clone $this->cache[$derived_key] : $this->cache[$derived_key];
} else {
$this->cache_misses++;
return false;
}
}
if ( $this->redis->exists( $derived_key ) ) {
$this->cache_hits++;
$value = $this->restore_value_from_redis( $this->redis->get( $derived_key ) );
} else {
$this->cache_misses;
return false;
}
$this->add_to_internal_cache( $derived_key, $value );
return is_object( $value ) ? clone $value : $value;
}
/**
* Sets a value in cache.
*
* The value is set whether or not this key already exists in Redis.
*
* @param string $key The key under which to store the value.
* @param mixed $value The value to store.
* @param string $group The group value appended to the $key.
* @param int $expiration The expiration time, defaults to 0.
*
* @return bool Returns TRUE on success or FALSE on failure.
*/
public function set( $key, $value, $group = 'default', $expiration = 0 ) {
$derived_key = $this->build_key( $key, $group );
// If group is a non-Redis group, save to internal cache, not Redis
if ( in_array( $group, $this->no_redis_groups ) ) {
$this->add_to_internal_cache( $derived_key, $value );
return true;
}
// Save to Redis
$expiration = absint( $expiration );
if ( $expiration ) {
$result = $this->parse_predis_response( $this->redis->setex( $derived_key, $expiration, $this->prepare_value_for_redis( $value ) ) );
} else {
$result = $this->parse_predis_response( $this->redis->set( $derived_key, $this->prepare_value_for_redis( $value ) ) );
}
return $result;
}
/**
* Increment a Redis counter by the amount specified
*
* @param string $key
* @param int $offset
* @param string $group
* @return bool
*/
public function increment( $key, $offset = 1, $group = 'default' ) {
$derived_key = $this->build_key( $key, $group );
$offset = (int) $offset;
// If group is a non-Redis group, save to internal cache, not Redis
if ( in_array( $group, $this->no_redis_groups ) ) {
$value = $this->get_from_internal_cache( $derived_key );
$value += $offset;
$this->add_to_internal_cache( $derived_key, $value );
return true;
}
// Save to Redis
$result = $this->parse_predis_response( $this->redis->incrBy( $derived_key, $offset ) );
$this->add_to_internal_cache( $derived_key, (int) $this->redis->get( $derived_key ) );
return $result;
}
/**
* Decrement a Redis counter by the amount specified
*
* @param string $key
* @param int $offset
* @param string $group
* @return bool
*/
public function decrement( $key, $offset = 1, $group = 'default' ) {
$derived_key = $this->build_key( $key, $group );
$offset = (int) $offset;
// If group is a non-Redis group, save to internal cache, not Redis
if ( in_array( $group, $this->no_redis_groups ) ) {
$value = $this->get_from_internal_cache( $derived_key );
$value -= $offset;
$this->add_to_internal_cache( $derived_key, $value );
return true;
}
// Save to Redis
$result = $this->parse_predis_response( $this->redis->decrBy( $derived_key, $offset ) );
$this->add_to_internal_cache( $derived_key, (int) $this->redis->get( $derived_key ) );
return $result;
}
/**
* Render data about current cache requests
*
* @return string
*/
public function stats() {
?><p>
<strong>Cache Hits:</strong> <?php echo number_format_i18n( $this->cache_hits ); ?><br />
<strong>Cache Misses:</strong> <?php echo number_format_i18n( $this->cache_misses ); ?><br />
</p>
<p> </p>
<p><strong>Caches Retrieved:</strong></p>
<ul>
<li><em>prefix:group:key - size in kilobytes</em></li>
<?php foreach ( $this->cache as $group => $cache ) : ?>
<li><?php echo esc_html( $group ); ?> - <?php echo number_format_i18n( strlen( serialize( $cache ) ) / 1024, 2 ); ?> kb</li>
<?php endforeach; ?>
</ul><?php
}
/**
* Builds a key for the cached object using the blog_id, key, and group values.
*
* @author Ryan Boren This function is inspired by the original WP Memcached Object cache.
* @link http://wordpress.org/extend/plugins/memcached/
*
* @param string $key The key under which to store the value.
* @param string $group The group value appended to the $key.
*
* @return string
*/
public function build_key( $key, $group = 'default' ) {
if ( empty( $group ) ) {
$group = 'default';
}
if ( false !== array_search( $group, $this->global_groups ) ) {
$prefix = $this->global_prefix;
} else {
$prefix = $this->blog_prefix;
}
return preg_replace( '/\s+/', '', WP_CACHE_KEY_SALT . "$prefix$group:$key" );
}
/**
* Prepare a value for storage in Redis, which only accepts strings
*
* @param mixed $value
* @return string
*/
protected function prepare_value_for_redis( $value ) {
$value = maybe_serialize( $value );
return $value;
}
/**
* Restore a value stored in Redis to its original data type
*
* @param string $value
* @return mixed
*/
protected function restore_value_from_redis( $value ) {
$value = maybe_unserialize( $value );
return $value;
}
/**
* Convert the response fro Predis into something meaningful
*
* @param mixed $response
* @return mixed
*/
protected function parse_predis_response( $response ) {
if ( is_bool( $response ) ) {
return $response;
}
if ( is_numeric( $response ) ) {
return (bool) $response;
}
if ( is_object( $response ) && method_exists( $response, 'getPayload' ) ) {
return 'OK' === $response->getPayload();
}
return false;
}
/**
* Simple wrapper for saving object to the internal cache.
*
* @param string $derived_key Key to save value under.
* @param mixed $value Object value.
*/
public function add_to_internal_cache( $derived_key, $value ) {
$this->cache[$derived_key] = $value;
}
/**
* Get a value specifically from the internal, run-time cache, not Redis.
*
* @param int|string $key Key value.
* @param int|string $group Group that the value belongs to.
*
* @return bool|mixed Value on success; false on failure.
*/
public function get_from_internal_cache( $key, $group ) {
$derived_key = $this->build_key( $key, $group );
if ( isset( $this->cache[ $derived_key ] ) ) {
return $this->cache[ $derived_key ];
}
return false;
}
/**
* In multisite, switch blog prefix when switching blogs
*
* @param int $_blog_id
* @return bool
*/
public function switch_to_blog( $_blog_id ) {
if ( ! is_multisite() ) {
return false;
}
$this->blog_prefix = $_blog_id . ':';
return true;
}
/**
* Sets the list of global groups.
*
* @param array $groups List of groups that are global.
*/
public function add_global_groups( $groups ) {
$groups = (array) $groups;
$this->global_groups = array_unique( array_merge( $this->global_groups, $groups ) );
}
/**
* Sets the list of groups not to be cached by Redis.
*
* @param array $groups List of groups that are to be ignored.
*/
public function add_non_persistent_groups( $groups ) {
$groups = (array) $groups;
$this->no_redis_groups = array_unique( array_merge( $this->no_redis_groups, $groups ) );
}
}