<?php

/*
Plugin Name: Memcached
Description: Memcached backend for the WP Object Cache.
Version: 2.0.1
Plugin URI: http://wordpress.org/extend/plugins/memcached/
Author: Ryan Boren, Denis de Bernardy, Matt Martz

Install this file to wp-content/object-cache.php
*/

function wp_cache_add($key, $data, $flag = '', $expire = 0) {
global $wp_object_cache;

return $wp_object_cache->add($key, $data, $flag, $expire);
}

function wp_cache_incr($key, $n = 1, $flag = '') {
global $wp_object_cache;

return $wp_object_cache->incr($key, $n, $flag);
}

function wp_cache_decr($key, $n = 1, $flag = '') {
global $wp_object_cache;

return $wp_object_cache->decr($key, $n, $flag);
}

function wp_cache_close() {
global $wp_object_cache;

return $wp_object_cache->close();
}

function wp_cache_delete($id, $flag = '') {
global $wp_object_cache;

return $wp_object_cache->delete($id, $flag);
}

function wp_cache_key_delete($key) {
global $wp_object_cache;

return $wp_object_cache->key_delete($key);
}

function wp_cache_flush() {
global $wp_object_cache;

return $wp_object_cache->flush();
}

function wp_cache_get($id, $flag = '') {
global $wp_object_cache;

return $wp_object_cache->get($id, $flag);
}

function wp_cache_init() {
global $wp_object_cache;

$wp_object_cache = new WP_Object_Cache();
}

function wp_cache_replace($key, $data, $flag = '', $expire = 0) {
global $wp_object_cache;

return $wp_object_cache->replace($key, $data, $flag, $expire);
}

function wp_cache_set($key, $data, $flag = '', $expire = 0) {
global $wp_object_cache;

if ( defined('WP_INSTALLING') == false )
return $wp_object_cache->set($key, $data, $flag, $expire);
else
return $wp_object_cache->delete($key, $flag);
}

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 ('users', 'userlogins', 'usermeta', 'site-options', 'site-lookup', 'blog-lookup', 'blog-details', 'rss');

var $no_mc_groups = array( 'comment', 'counts' );

var $autoload_groups = array ('options');

var $cache = array();
var $mc = array();
var $stats = array();
var $group_ops = array();

var $cache_enabled = true;
var $default_expiration = 0;

function add($id, $data, $group = 'default', $expire = 0) {
$key = $this->key($id, $group);

if ( in_array($group, $this->no_mc_groups) ) {
$this->cache[$key] = $data;
return true;
} elseif ( isset($this->cache[$key]) && $this->cache[$key] !== false ) {
return false;
}

$mc =& $this->get_mc($group);
$expire = ($expire == 0) ? $this->default_expiration : $expire;
$result = $mc->add($key, $data, false, $expire);

if ( false !== $result ) {
@ ++$this->stats['add'];
$this->group_ops[$group][] = "add $id";
$this->cache[$key] = $data;
}

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, $group) {
$key = $this->key($id, $group);
$mc =& $this->get_mc($group);

return $mc->increment($key, $n);
}

function decr($id, $n, $group) {
$key = $this->key($id, $group);
$mc =& $this->get_mc($group);

return $mc->decrement($key, $n);
}

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 key_delete($key) {

$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() {
// Don't flush if multi-blog.
if ( function_exists('is_site_admin') || defined('CUSTOM_USER_TABLE') && defined('CUSTOM_USER_META_TABLE') )
return true;

$ret = true;
foreach ( array_keys($this->mc) as $group )
$ret &= $this->mc[$group]->flush();
return $ret;
}

function get($id, $group = 'default') {
$key = $this->key($id, $group);
$mc =& $this->get_mc($group);

if ( isset($this->cache[$key]) )
$value = $this->cache[$key];
else if ( in_array($group, $this->no_mc_groups) )
$value = false;
else
$value = $mc->get($key);

@ ++$this->stats['get'];
$this->group_ops[$group][] = "get $id";

if ( NULL === $value )
$value = false;

$this->cache[$key] = $value;

if ( 'checkthedatabaseplease' == $value )
$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]) ) {
$return[$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 key($key, $group) {
if ( empty($group) )
$group = 'default';

if ( false !== array_search($group, $this->global_groups) )
$prefix = $this->global_prefix;
else
$prefix = $this->blog_prefix;

return preg_replace('/\s+/', '', "$prefix$group:$key");
}

function replace($id, $data, $group = 'default', $expire = 0) {
$key = $this->key($id, $group);
$expire = ($expire == 0) ? $this->default_expiration : $expire;
$mc =& $this->get_mc($group);
$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;
$this->cache[$key] = $data;

if ( in_array($group, $this->no_mc_groups) )
return true;

$expire = ($expire == 0) ? $this->default_expiration : $expire;
$mc =& $this->get_mc($group);
$result = $mc->set($key, $data, false, $expire);

return $result;
}

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() {
echo "<p>\n";
foreach ( $this->stats as $stat => $n ) {
echo "$stat $n";
echo "
\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( $ops, 0, 500 );
echo "<big>Too many to show! Show them anyway.</big>\n";
}
echo "<h4>$group commands</h4>";
echo "
\n";
            $lines = array();
            foreach ( $ops as $op ) {
                $lines[] = $this->colorize_debug_line($op);
            }
            print_r($lines);
            echo "
\n";
}
if ( $this->debug )
var_dump($this->memcache_debug);
}

function &get_mc($group) {
if ( isset($this->mc[$group]) )
return $this->mc[$group];
return $this->mc['default'];
}

function failure_callback($host, $port) {
//error_log("Connection failure for $host:$port\n", 3, '/tmp/memcached.txt');
}

function WP_Object_Cache() {
global $memcached_servers;

if ( isset($memcached_servers) )
$buckets = $memcached_servers;
else
$buckets = array('127.0.0.1');

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 ) {
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 = ( is_multisite() || defined('CUSTOM_USER_TABLE') && defined('CUSTOM_USER_META_TABLE') ) ? '' : $table_prefix;
$this->blog_prefix = ( is_multisite() ? $blog_id : $table_prefix ) . ':';

$this->cache_hits =& $this->stats['get'];
$this->cache_misses =& $this->stats['add'];
}
}