Permalink
Find file Copy path
596 lines (435 sloc) 13.8 KB
<?php
/*
Plugin Name: Memcached
Description: Memcached backend for the WP Object Cache.
Version: 3.0.1
Plugin URI: http://wordpress.org/extend/plugins/memcached/
Author: Ryan Boren, Denis de Bernardy, Matt Martz, Andy Skelton
Install this file to wp-content/object-cache.php
*/
// Users with setups where multiple installs share a common wp-config.php or $table_prefix
// can use this to guarantee uniqueness for the keys generated by this object cache
if ( ! defined( 'WP_CACHE_KEY_SALT' ) ) {
define( 'WP_CACHE_KEY_SALT', '' );
}
function wp_cache_add( $key, $data, $group = '', $expire = 0 ) {
global $wp_object_cache;
return $wp_object_cache->add( $key, $data, $group, $expire );
}
function wp_cache_incr( $key, $n = 1, $group = '' ) {
global $wp_object_cache;
return $wp_object_cache->incr( $key, $n, $group );
}
function wp_cache_decr( $key, $n = 1, $group = '' ) {
global $wp_object_cache;
return $wp_object_cache->decr( $key, $n, $group );
}
function wp_cache_close() {
global $wp_object_cache;
return $wp_object_cache->close();
}
function wp_cache_delete( $key, $group = '' ) {
global $wp_object_cache;
return $wp_object_cache->delete( $key, $group );
}
function wp_cache_flush() {
global $wp_object_cache;
return $wp_object_cache->flush();
}
function wp_cache_get( $key, $group = '', $force = false ) {
global $wp_object_cache;
return $wp_object_cache->get( $key, $group, $force );
}
/**
* Retrieve multiple cache entries
*
* @param array $groups Array of arrays, of groups and keys to retrieve
* @return mixed
*/
function wp_cache_get_multi( $groups ) {
global $wp_object_cache;
return $wp_object_cache->get_multi( $groups );
}
function wp_cache_init() {
global $wp_object_cache;
$wp_object_cache = new WP_Object_Cache();
}
function wp_cache_replace( $key, $data, $group = '', $expire = 0 ) {
global $wp_object_cache;
return $wp_object_cache->replace( $key, $data, $group, $expire );
}
function wp_cache_set( $key, $data, $group = '', $expire = 0 ) {
global $wp_object_cache;
if ( defined( 'WP_INSTALLING' ) == false ) {
return $wp_object_cache->set( $key, $data, $group, $expire );
} else {
return $wp_object_cache->delete( $key, $group );
}
}
function wp_cache_switch_to_blog( $blog_id ) {
global $wp_object_cache;
return $wp_object_cache->switch_to_blog( $blog_id );
}
function wp_cache_add_global_groups( $groups ) {
global $wp_object_cache;
$wp_object_cache->add_global_groups( $groups );
}
function wp_cache_add_non_persistent_groups( $groups ) {
global $wp_object_cache;
$wp_object_cache->add_non_persistent_groups( $groups );
}
class WP_Object_Cache {
var $global_groups = array( 'WP_Object_Cache_global' );
var $no_mc_groups = array();
var $cache = array();
var $mc = array();
var $stats = array();
var $group_ops = array();
var $flush_number = array();
var $global_flush_number = null;
var $cache_enabled = true;
var $default_expiration = 0;
var $max_expiration = 2592000; // 30 days
var $stats_callback = null;
var $connection_errors = array();
function add( $id, $data, $group = 'default', $expire = 0 ) {
$key = $this->key( $id, $group );
if ( is_object( $data ) ) {
$data = clone $data;
}
if ( in_array( $group, $this->no_mc_groups ) ) {
$this->cache[ $key ] = $data;
return true;
} elseif ( isset( $this->cache[ $key ] ) && false !== $this->cache[ $key ] ) {
return false;
}
$mc =& $this->get_mc( $group );
$expire = intval( $expire );
if ( 0 === $expire || $expire > $this->max_expiration ) {
$expire = $this->default_expiration;
}
$result = $mc->add( $key, $data, false, $expire );
if ( false !== $result ) {
++$this->stats['add'];
$this->group_ops[ $group ][] = "add $id";
$this->cache[ $key ] = $data;
} else if ( false === $result && true === isset( $this->cache[$key] ) && false === $this->cache[$key] ) {
/*
* Here we unset local cache if remote add failed and local cache value is equal to `false` in order
* to update the local cache anytime we get a new information from remote server. This way, the next
* cache get will go to remote server and will fetch recent data.
*/
unset( $this->cache[$key] );
}
return $result;
}
function add_global_groups( $groups ) {
if ( ! is_array( $groups ) ) {
$groups = (array) $groups;
}
$this->global_groups = array_merge( $this->global_groups, $groups );
$this->global_groups = array_unique( $this->global_groups );
}
function add_non_persistent_groups( $groups ) {
if ( ! is_array( $groups ) ) {
$groups = (array) $groups;
}
$this->no_mc_groups = array_merge( $this->no_mc_groups, $groups );
$this->no_mc_groups = array_unique( $this->no_mc_groups );
}
function incr( $id, $n = 1, $group = 'default' ) {
$key = $this->key( $id, $group );
$mc =& $this->get_mc( $group );
$this->cache[ $key ] = $mc->increment( $key, $n );
return $this->cache[ $key ];
}
function decr( $id, $n = 1, $group = 'default' ) {
$key = $this->key( $id, $group );
$mc =& $this->get_mc( $group );
$this->cache[ $key ] = $mc->decrement( $key, $n );
return $this->cache[ $key ];
}
function close() {
foreach ( $this->mc as $bucket => $mc ) {
$mc->close();
}
}
function delete( $id, $group = 'default' ) {
$key = $this->key( $id, $group );
if ( in_array( $group, $this->no_mc_groups ) ) {
unset( $this->cache[ $key ] );
return true;
}
$mc =& $this->get_mc( $group );
$result = $mc->delete( $key );
++$this->stats['delete'];
$this->group_ops[ $group ][] = "delete $id";
if ( false !== $result ) {
unset( $this->cache[ $key ] );
}
return $result;
}
function flush() {
// Do not use the memcached flush method. It acts on an
// entire memcached server, affecting all sites.
// Flush is also unusable in some setups, e.g. twemproxy.
// Instead, rotate the key prefix for the current site.
// Global keys are rotated when flushing on the main site.
$this->cache = array();
$this->rotate_site_keys();
if ( is_main_site() ) {
$this->rotate_global_keys();
}
}
function rotate_site_keys() {
$this->add( 'flush_number', intval( microtime( true ) * 1e6 ), 'WP_Object_Cache' );
$this->flush_number[ $this->blog_prefix ] = $this->incr( 'flush_number', 1, 'WP_Object_Cache' );
}
function rotate_global_keys() {
$this->add( 'flush_number', intval( microtime( true ) * 1e6 ), 'WP_Object_Cache_global' );
$this->global_flush_number = $this->incr( 'flush_number', 1, 'WP_Object_Cache_global' );
}
function get( $id, $group = 'default', $force = false ) {
$key = $this->key( $id, $group );
$mc =& $this->get_mc( $group );
if ( isset( $this->cache[ $key ] ) && ( ! $force || in_array( $group, $this->no_mc_groups ) ) ) {
if ( is_object( $this->cache[ $key ] ) ) {
$value = clone $this->cache[ $key ];
} else {
$value = $this->cache[ $key ];
}
} else if ( in_array( $group, $this->no_mc_groups ) ) {
$this->cache[ $key ] = $value = false;
} else {
$value = $mc->get( $key );
if ( null === $value ) {
$value = false;
}
$this->cache[ $key ] = $value;
}
++$this->stats['get'];
$this->group_ops[ $group ][] = "get $id";
if ( 'checkthedatabaseplease' === $value ) {
unset( $this->cache[ $key ] );
$value = false;
}
return $value;
}
function get_multi( $groups ) {
/*
format: $get['group-name'] = array( 'key1', 'key2' );
*/
$return = array();
foreach ( $groups as $group => $ids ) {
$mc =& $this->get_mc( $group );
foreach ( $ids as $id ) {
$key = $this->key( $id, $group );
if ( isset( $this->cache[ $key ] ) ) {
if ( is_object( $this->cache[ $key ] ) ) {
$return[ $key ] = clone $this->cache[ $key ];
} else {
$return[ $key ] = $this->cache[ $key ];
}
continue;
} else if ( in_array( $group, $this->no_mc_groups ) ) {
$return[ $key ] = false;
continue;
} else {
$return[ $key ] = $mc->get( $key );
}
}
if ( $to_get ) {
$vals = $mc->get_multi( $to_get );
$return = array_merge( $return, $vals );
}
}
++$this->stats['get_multi'];
$this->group_ops[ $group ][] = "get_multi $id";
$this->cache = array_merge( $this->cache, $return );
return $return;
}
function flush_prefix( $group ) {
if ( 'WP_Object_Cache' === $group || 'WP_Object_Cache_global' === $group ) {
// Never flush the flush numbers.
$number = '_';
} elseif ( false !== array_search( $group, $this->global_groups ) ) {
if ( ! isset( $this->global_flush_number ) ) {
$this->global_flush_number = intval( $this->get( 'flush_number', 'WP_Object_Cache_global' ) );
}
if ( 0 === $this->global_flush_number ) {
$this->rotate_global_keys();
}
$number = $this->global_flush_number;
} else {
if ( ! isset( $this->flush_number[ $this->blog_prefix ] ) ) {
$this->flush_number[ $this->blog_prefix ] = intval( $this->get( 'flush_number', 'WP_Object_Cache' ) );
}
if ( 0 === $this->flush_number[ $this->blog_prefix ] ) {
$this->rotate_site_keys();
}
$number = $this->flush_number[ $this->blog_prefix ];
}
return $number . ':';
}
function key( $key, $group ) {
if ( empty( $group ) ) {
$group = 'default';
}
$prefix = $this->key_salt;
$prefix .= $this->flush_prefix( $group );
if ( false !== array_search( $group, $this->global_groups ) ) {
$prefix .= $this->global_prefix;
} else {
$prefix .= $this->blog_prefix;
}
return preg_replace( '/\s+/', '', "$prefix:$group:$key" );
}
function replace( $id, $data, $group = 'default', $expire = 0 ) {
$key = $this->key( $id, $group );
$expire = intval( $expire );
if ( 0 === $expire || $expire > $this->max_expiration ) {
$expire = $this->default_expiration;
}
$mc =& $this->get_mc( $group );
if ( is_object( $data ) ) {
$data = clone $data;
}
$result = $mc->replace( $key, $data, false, $expire );
if ( false !== $result ) {
$this->cache[ $key ] = $data;
}
return $result;
}
function set( $id, $data, $group = 'default', $expire = 0 ) {
$key = $this->key( $id, $group );
if ( isset( $this->cache[ $key ] ) && ( 'checkthedatabaseplease' === $this->cache[ $key ] ) ) {
return false;
}
if ( is_object( $data ) ) {
$data = clone $data;
}
$this->cache[ $key ] = $data;
if ( in_array( $group, $this->no_mc_groups ) ) {
return true;
}
$expire = intval( $expire );
if ( 0 === $expire || $expire > $this->max_expiration ) {
$expire = $this->default_expiration;
}
$mc =& $this->get_mc( $group );
$result = $mc->set( $key, $data, false, $expire );
++$this->stats[ 'set' ];
$this->group_ops[$group][] = "set $id";
return $result;
}
function switch_to_blog( $blog_id ) {
global $table_prefix;
$blog_id = (int) $blog_id;
$this->blog_prefix = ( is_multisite() ? $blog_id : $table_prefix );
}
function colorize_debug_line( $line ) {
$colors = array(
'get' => 'green',
'set' => 'purple',
'add' => 'blue',
'delete' => 'red',
);
$cmd = substr( $line, 0, strpos( $line, ' ' ) );
$cmd2 = "<span style='color:{$colors[$cmd]}'>$cmd</span>";
return $cmd2 . substr( $line, strlen( $cmd ) ) . "\n";
}
function stats() {
if ( $this->stats_callback && is_callable( $this->stats_callback ) ) {
return call_user_func( $this->stats_callback );
}
echo "<p>\n";
foreach ( $this->stats as $stat => $n ) {
echo "<strong>$stat</strong> $n";
echo "<br/>\n";
}
echo "</p>\n";
echo '<h3>Memcached:</h3>';
foreach ( $this->group_ops as $group => $ops ) {
if ( ! isset( $_GET['debug_queries'] ) && 500 < count( $ops ) ) {
$ops = array_slice( $ops, 0, 500 );
echo "<big>Too many to show! <a href='" . add_query_arg( 'debug_queries', 'true' ) . "'>Show them anyway</a>.</big>\n";
}
echo "<h4>$group commands</h4>";
echo "<pre>\n";
$lines = array();
foreach ( $ops as $op ) {
$lines[] = $this->colorize_debug_line( $op );
}
print_r( $lines );
echo "</pre>\n";
}
}
function &get_mc( $group ) {
if ( isset( $this->mc[ $group ] ) ) {
return $this->mc[ $group ];
}
return $this->mc['default'];
}
function failure_callback( $host, $port ) {
$this->connection_errors[] = array(
'host' => $host,
'port' => $port,
);
}
function salt_keys( $key_salt ) {
if ( strlen( $key_salt ) ) {
$this->key_salt = $key_salt . ':';
} else {
$this->key_salt = '';
}
}
function __construct() {
$this->stats = array(
'get' => 0,
'get_multi' => 0,
'add' => 0,
'set' => 0,
'delete' => 0,
);
global $memcached_servers;
if ( isset( $memcached_servers ) ) {
$buckets = $memcached_servers;
} else {
$buckets = array( '127.0.0.1:11211' );
}
reset( $buckets );
if ( is_int( key( $buckets ) ) ) {
$buckets = array( 'default' => $buckets );
}
foreach ( $buckets as $bucket => $servers ) {
$this->mc[ $bucket ] = new Memcache();
foreach ( $servers as $server ) {
if ( 'unix://' == substr( $server, 0, 7 ) ) {
$node = $server;
$port = 0;
} else {
list ( $node, $port ) = explode( ':', $server );
if ( ! $port ) {
$port = ini_get( 'memcache.default_port' );
}
$port = intval( $port );
if ( ! $port ) {
$port = 11211;
}
}
$this->mc[ $bucket ]->addServer( $node, $port, true, 1, 1, 15, true, array( $this, 'failure_callback' ) );
$this->mc[ $bucket ]->setCompressThreshold( 20000, 0.2 );
}
}
global $blog_id, $table_prefix;
$this->global_prefix = '';
$this->blog_prefix = '';
if ( function_exists( 'is_multisite' ) ) {
$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 );
}
$this->salt_keys( WP_CACHE_KEY_SALT );
$this->cache_hits =& $this->stats['get'];
$this->cache_misses =& $this->stats['add'];
}
}