<?php
/**
- * Functions to get cache objects
+ * Functions to get cache objects.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
*
* @file
* @ingroup Cache
*/
-global $wgCaches;
-$wgCaches = array();
-
/**
- * Get a cache object.
- * @param $inputType Integer: cache type, one the the CACHE_* constants.
+ * Functions to get cache objects
*
- * @return BagOStuff
+ * @ingroup Cache
*/
-function &wfGetCache( $inputType ) {
- global $wgCaches, $wgMemCachedServers, $wgMemCachedDebug, $wgMemCachedPersistent;
- $cache = false;
+class ObjectCache {
+ static $instances = array();
- if ( $inputType == CACHE_ANYTHING ) {
- reset( $wgCaches );
- $type = key( $wgCaches );
- if ( $type === false || $type === CACHE_NONE ) {
- $type = CACHE_DB;
+ /**
+ * Get a cached instance of the specified type of cache object.
+ *
+ * @param $id
+ *
+ * @return object
+ */
+ static function getInstance( $id ) {
+ if ( isset( self::$instances[$id] ) ) {
+ return self::$instances[$id];
}
- } else {
- $type = $inputType;
+
+ $object = self::newFromId( $id );
+ self::$instances[$id] = $object;
+ return $object;
}
- if ( $type == CACHE_MEMCACHED ) {
- if ( !array_key_exists( CACHE_MEMCACHED, $wgCaches ) ) {
- $wgCaches[CACHE_MEMCACHED] = new MemCachedClientforWiki(
- array('persistant' => $wgMemCachedPersistent, 'compress_threshold' => 1500 ) );
- $wgCaches[CACHE_MEMCACHED]->set_servers( $wgMemCachedServers );
- $wgCaches[CACHE_MEMCACHED]->set_debug( $wgMemCachedDebug );
- }
- $cache =& $wgCaches[CACHE_MEMCACHED];
- } 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( 'xcache_get' ) ) {
- $wgCaches[CACHE_ACCEL] = new XCacheBagOStuff();
- } elseif( function_exists( 'wincache_ucache_get' ) ) {
- $wgCaches[CACHE_ACCEL] = new WinCacheBagOStuff();
- } else {
- $wgCaches[CACHE_ACCEL] = false;
- }
- }
- if ( $wgCaches[CACHE_ACCEL] !== false ) {
- $cache =& $wgCaches[CACHE_ACCEL];
- }
- } elseif ( $type == CACHE_DBA ) {
- if ( !array_key_exists( CACHE_DBA, $wgCaches ) ) {
- $wgCaches[CACHE_DBA] = new DBABagOStuff;
- }
- $cache =& $wgCaches[CACHE_DBA];
+ /**
+ * Clear all the cached instances.
+ */
+ static function clear() {
+ self::$instances = array();
}
- if ( $type == CACHE_DB || ( $inputType == CACHE_ANYTHING && $cache === false ) ) {
- if ( !array_key_exists( CACHE_DB, $wgCaches ) ) {
- $wgCaches[CACHE_DB] = new SqlBagOStuff('objectcache');
+ /**
+ * Create a new cache object of the specified type.
+ *
+ * @param $id
+ *
+ * @return ObjectCache
+ */
+ static function newFromId( $id ) {
+ global $wgObjectCaches;
+
+ if ( !isset( $wgObjectCaches[$id] ) ) {
+ throw new MWException( "Invalid object cache type \"$id\" requested. " .
+ "It is not present in \$wgObjectCaches." );
}
- $cache =& $wgCaches[CACHE_DB];
+
+ return self::newFromParams( $wgObjectCaches[$id] );
}
- if ( $cache === false ) {
- if ( !array_key_exists( CACHE_NONE, $wgCaches ) ) {
- $wgCaches[CACHE_NONE] = new FakeMemCachedClient;
+ /**
+ * Create a new cache object from parameters
+ *
+ * @param $params array
+ *
+ * @return ObjectCache
+ */
+ static function newFromParams( $params ) {
+ if ( isset( $params['factory'] ) ) {
+ return call_user_func( $params['factory'], $params );
+ } elseif ( isset( $params['class'] ) ) {
+ $class = $params['class'];
+ return new $class( $params );
+ } else {
+ throw new MWException( "The definition of cache type \"" . print_r( $params, true ) . "\" lacks both " .
+ "factory and class parameters." );
}
- $cache =& $wgCaches[CACHE_NONE];
}
- return $cache;
-}
-
-/** Get the main cache object */
-function &wfGetMainCache() {
- global $wgMainCacheType;
- $ret =& wfGetCache( $wgMainCacheType );
- return $ret;
-}
+ /**
+ * Factory function referenced from DefaultSettings.php for CACHE_ANYTHING
+ *
+ * CACHE_ANYTHING means that stuff has to be cached, not caching is not an option.
+ * If a caching method is configured for any of the main caches ($wgMainCacheType,
+ * $wgMessageCacheType, $wgParserCacheType), then CACHE_ANYTHING will effectively
+ * be an alias to the configured cache choice for that.
+ * If no cache choice is configured (by default $wgMainCacheType is CACHE_NONE),
+ * then CACHE_ANYTHING will forward to CACHE_DB.
+ */
+ static function newAnything( $params ) {
+ global $wgMainCacheType, $wgMessageCacheType, $wgParserCacheType;
+ $candidates = array( $wgMainCacheType, $wgMessageCacheType, $wgParserCacheType );
+ foreach ( $candidates as $candidate ) {
+ if ( $candidate !== CACHE_NONE && $candidate !== CACHE_ANYTHING ) {
+ return self::getInstance( $candidate );
+ }
+ }
+ return self::getInstance( CACHE_DB );
+ }
-/** Get the cache object used by the message cache */
-function &wfGetMessageCacheStorage() {
- global $wgMessageCacheType;
- $ret =& wfGetCache( $wgMessageCacheType );
- return $ret;
-}
+ /**
+ * Factory function referenced from DefaultSettings.php for CACHE_ACCEL.
+ *
+ * @return ObjectCache
+ */
+ static function newAccelerator( $params ) {
+ if ( function_exists( 'apc_fetch') ) {
+ $id = 'apc';
+ } elseif( function_exists( 'xcache_get' ) && wfIniGetBool( 'xcache.var_size' ) ) {
+ $id = 'xcache';
+ } elseif( function_exists( 'wincache_ucache_get' ) ) {
+ $id = 'wincache';
+ } else {
+ throw new MWException( "CACHE_ACCEL requested but no suitable object " .
+ "cache is present. You may want to install APC." );
+ }
+ return self::newFromId( $id );
+ }
-/** Get the cache object used by the parser cache */
-function &wfGetParserCacheStorage() {
- global $wgParserCacheType;
- $ret =& wfGetCache( $wgParserCacheType );
- return $ret;
+ /**
+ * Factory function that creates a memcached client object.
+ *
+ * This always uses the PHP client, since the PECL client has a different
+ * hashing scheme and a different interpretation of the flags bitfield, so
+ * switching between the two clients randomly would be disasterous.
+ *
+ * @param $params array
+ *
+ * @return MemcachedPhpBagOStuff
+ */
+ static function newMemcached( $params ) {
+ return new MemcachedPhpBagOStuff( $params );
+ }
}