diff options
Diffstat (limited to 'includes/objectcache/MemcachedPeclBagOStuff.php')
-rw-r--r-- | includes/objectcache/MemcachedPeclBagOStuff.php | 237 |
1 files changed, 237 insertions, 0 deletions
diff --git a/includes/objectcache/MemcachedPeclBagOStuff.php b/includes/objectcache/MemcachedPeclBagOStuff.php new file mode 100644 index 00000000..76886ebb --- /dev/null +++ b/includes/objectcache/MemcachedPeclBagOStuff.php @@ -0,0 +1,237 @@ +<?php +/** + * Object caching using memcached. + * + * 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 + */ + +/** + * A wrapper class for the PECL memcached client + * + * @ingroup Cache + */ +class MemcachedPeclBagOStuff extends MemcachedBagOStuff { + + /** + * Constructor + * + * Available parameters are: + * - servers: The list of IP:port combinations holding the memcached servers. + * - persistent: Whether to use a persistent connection + * - compress_threshold: The minimum size an object must be before it is compressed + * - timeout: The read timeout in microseconds + * - connect_timeout: The connect timeout in seconds + * - serializer: May be either "php" or "igbinary". Igbinary produces more compact + * values, but serialization is much slower unless the php.ini option + * igbinary.compact_strings is off. + */ + function __construct( $params ) { + $params = $this->applyDefaultParams( $params ); + + if ( $params['persistent'] ) { + // The pool ID must be unique to the server/option combination. + // The Memcached object is essentially shared for each pool ID. + // We can only resuse a pool ID if we keep the config consistent. + $this->client = new Memcached( md5( serialize( $params ) ) ); + if ( count( $this->client->getServerList() ) ) { + wfDebug( __METHOD__ . ": persistent Memcached object already loaded.\n" ); + return; // already initialized; don't add duplicate servers + } + } else { + $this->client = new Memcached; + } + + if ( !isset( $params['serializer'] ) ) { + $params['serializer'] = 'php'; + } + + // The compression threshold is an undocumented php.ini option for some + // reason. There's probably not much harm in setting it globally, for + // compatibility with the settings for the PHP client. + ini_set( 'memcached.compression_threshold', $params['compress_threshold'] ); + + // Set timeouts + $this->client->setOption( Memcached::OPT_CONNECT_TIMEOUT, $params['connect_timeout'] * 1000 ); + $this->client->setOption( Memcached::OPT_SEND_TIMEOUT, $params['timeout'] ); + $this->client->setOption( Memcached::OPT_RECV_TIMEOUT, $params['timeout'] ); + $this->client->setOption( Memcached::OPT_POLL_TIMEOUT, $params['timeout'] / 1000 ); + + // Set libketama mode since it's recommended by the documentation and + // is as good as any. There's no way to configure libmemcached to use + // hashes identical to the ones currently in use by the PHP client, and + // even implementing one of the libmemcached hashes in pure PHP for + // forwards compatibility would require MWMemcached::get_sock() to be + // rewritten. + $this->client->setOption( Memcached::OPT_LIBKETAMA_COMPATIBLE, true ); + + // Set the serializer + switch ( $params['serializer'] ) { + case 'php': + $this->client->setOption( Memcached::OPT_SERIALIZER, Memcached::SERIALIZER_PHP ); + break; + case 'igbinary': + if ( !Memcached::HAVE_IGBINARY ) { + throw new MWException( __CLASS__.': the igbinary extension is not available ' . + 'but igbinary serialization was requested.' ); + } + $this->client->setOption( Memcached::OPT_SERIALIZER, Memcached::SERIALIZER_IGBINARY ); + break; + default: + throw new MWException( __CLASS__.': invalid value for serializer parameter' ); + } + $servers = array(); + foreach ( $params['servers'] as $host ) { + $servers[] = IP::splitHostAndPort( $host ); // (ip, port) + } + $this->client->addServers( $servers ); + } + + /** + * @param $key string + * @return Mixed + */ + public function get( $key ) { + $this->debugLog( "get($key)" ); + return $this->checkResult( $key, parent::get( $key ) ); + } + + /** + * @param $key string + * @param $value + * @param $exptime int + * @return bool + */ + public function set( $key, $value, $exptime = 0 ) { + $this->debugLog( "set($key)" ); + return $this->checkResult( $key, parent::set( $key, $value, $exptime ) ); + } + + /** + * @param $key string + * @param $time int + * @return bool + */ + public function delete( $key, $time = 0 ) { + $this->debugLog( "delete($key)" ); + $result = parent::delete( $key, $time ); + if ( $result === false && $this->client->getResultCode() === Memcached::RES_NOTFOUND ) { + // "Not found" is counted as success in our interface + return true; + } else { + return $this->checkResult( $key, $result ); + } + } + + /** + * @param $key string + * @param $value int + * @param $exptime int + * @return Mixed + */ + public function add( $key, $value, $exptime = 0 ) { + $this->debugLog( "add($key)" ); + return $this->checkResult( $key, parent::add( $key, $value, $exptime ) ); + } + + /** + * @param $key string + * @param $value int + * @param $exptime + * @return Mixed + */ + public function replace( $key, $value, $exptime = 0 ) { + $this->debugLog( "replace($key)" ); + return $this->checkResult( $key, parent::replace( $key, $value, $exptime ) ); + } + + /** + * @param $key string + * @param $value int + * @return Mixed + */ + public function incr( $key, $value = 1 ) { + $this->debugLog( "incr($key)" ); + $result = $this->client->increment( $key, $value ); + return $this->checkResult( $key, $result ); + } + + /** + * @param $key string + * @param $value int + * @return Mixed + */ + public function decr( $key, $value = 1 ) { + $this->debugLog( "decr($key)" ); + $result = $this->client->decrement( $key, $value ); + return $this->checkResult( $key, $result ); + } + + /** + * Check the return value from a client method call and take any necessary + * action. Returns the value that the wrapper function should return. At + * present, the return value is always the same as the return value from + * the client, but some day we might find a case where it should be + * different. + * + * @param $key string The key used by the caller, or false if there wasn't one. + * @param $result Mixed The return value + * @return Mixed + */ + protected function checkResult( $key, $result ) { + if ( $result !== false ) { + return $result; + } + switch ( $this->client->getResultCode() ) { + case Memcached::RES_SUCCESS: + break; + case Memcached::RES_DATA_EXISTS: + case Memcached::RES_NOTSTORED: + case Memcached::RES_NOTFOUND: + $this->debugLog( "result: " . $this->client->getResultMessage() ); + break; + default: + $msg = $this->client->getResultMessage(); + if ( $key !== false ) { + $server = $this->client->getServerByKey( $key ); + $serverName = "{$server['host']}:{$server['port']}"; + $msg = "Memcached error for key \"$key\" on server \"$serverName\": $msg"; + } else { + $msg = "Memcached error: $msg"; + } + wfDebugLog( 'memcached-serious', $msg ); + } + return $result; + } + + /** + * @param $keys Array + * @return Array + */ + public function getMulti( array $keys ) { + $this->debugLog( 'getMulti(' . implode( ', ', $keys ) . ')' ); + $callback = array( $this, 'encodeKey' ); + $result = $this->client->getMulti( array_map( $callback, $keys ) ); + return $this->checkResult( false, $result ); + } + + /* NOTE: there is no cas() method here because it is currently not supported + * by the BagOStuff interface and other BagOStuff subclasses, such as + * SqlBagOStuff. + */ +} |