wiki.techinc.nl/includes/ObjectCache.php

<?php
/**
 * @package MediaWiki
 * @subpackage Cache
 */

/**
 * FakeMemCachedClient imitates the API of memcached-client v. 0.1.2.
 * It acts as a memcached server with no RAM, that is, all objects are
 * cleared the moment they are set. All set operations succeed and all
 * get operations return null.
 * @package MediaWiki
 * @subpackage Cache
 */
class FakeMemCachedClient {
	function add ($key, $val, $exp = 0) { return true; }
	function decr ($key, $amt=1) { return null; }
	function delete ($key, $time = 0) { return false; }
	function disconnect_all () { }
	function enable_compress ($enable) { }
	function forget_dead_hosts () { }
	function get ($key) { return null; }
	function get_multi ($keys) { return array_pad(array(), count($keys), null); }
	function incr ($key, $amt=1) { return null; }
	function replace ($key, $value, $exp=0) { return false; }
	function run_command ($sock, $cmd) { return null; }
	function set ($key, $value, $exp=0){ return true; }
	function set_compress_threshold ($thresh){ }
	function set_debug ($dbg) { }
	function set_servers ($list) { }
}

global $wgCaches;
$wgCaches = array();

class ObjectCacheManager {
	/* @static */
	function getCache( $inputType ) {
		global $wgCaches, $wgMemCachedServers, $wgMemCachedDebug, $wgMemCachedPersistent;
		$cache = false;

		if ( $inputType == CACHE_ANYTHING ) {
			reset( $wgCaches );
			$type = key( $wgCaches );
			if ( $type === false || $type === CACHE_NONE ) {
				$type = CACHE_DB;
			}
		} else {
			$type = $inputType;
		}

		if ( $type == CACHE_MEMCACHED ) {
			if ( !array_key_exists( CACHE_MEMCACHED, $wgCaches ) ){
				$wgCaches[CACHE_DB] = new MemCachedClientforWiki(
					array('persistant' => $wgMemCachedPersistent, 'compress_threshold' => 1500 ) );
				$cache =& $wgCaches[CACHE_DB];
				$cache->set_servers( $wgMemCachedServers );
				$cache->set_debug( $wgMemCachedDebug );
			}
		} elseif ( $type == CACHE_ACCEL ) {
			if ( !array_key_exists( CACHE_ACCEL, $wgCaches ) ) {
				if ( function_exists( 'eaccelerator_get' ) ) {
					$wgCaches[CACHE_ACCEL] = new eAccelBagOStuff;
				} elseif ( function_exists( 'apc_fetch') ) {
					$wgCaches[CACHE_ACCEL] = new APCBagOStuff;
				} elseif ( function_exists( 'mmcache_get' ) ) {
					$wgCaches[CACHE_ACCEL] = new TurckBagOStuff;
				} else {
					$wgCaches[CACHE_ACCEL] = false;
				}
			}
			if ( $wgCaches[CACHE_ACCEL] !== false ) {
				$cache =& $wgCaches[CACHE_ACCEL];
			}
		}

		if ( $type == CACHE_DB || ( $inputType == CACHE_ANYTHING && $cache === false ) ) {
			if ( !array_key_exists( CACHE_DB, $wgCaches ) ) {
				$wgCaches[CACHE_DB] = new MediaWikiBagOStuff('objectcache');
			}
			$cache =& $wgCaches[CACHE_DB];
		}

		if ( $cache === false ) {
			if ( !array_key_exists( CACHE_NONE, $wgCaches ) ) {
				$wgCaches[CACHE_NONE] = new FakeMemCachedClient;
			}
			$cache =& $wgCaches[CACHE_NONE];
		}

		return $cache;
	}
	
	/** @static */
	function &getMainCache() {
		global $wgMainCacheType;
		$ret =& ObjectCacheManager::getCache( $wgMainCacheType );
		return $ret;
	}

	/** @static */
	function &getMessageCache() {
		global $wgMessageCacheType;
		$ret =& ObjectCacheManager::getCache( $wgMessageCacheType );
		return $ret;
	}
	
	/** @static */
	function &getParserCache() {
		global $wgParserCacheType;
		$ret =& ObjectCacheManager::getCache( $wgParserCacheType );
		return $ret;
	}
	
}

class MemCachedClientforWiki extends memcached {
	function _debugprint( $text ) {
		wfDebug( "memcached: $text\n" );
	}
}

?>