MemcachedPeclBagOStuff.php

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<?php
class MemcachedPeclBagOStuff extends MemcachedBagOStuff {

        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 );
        }

        public function get( $key ) {
                $this->debugLog( "get($key)" );
                return $this->checkResult( $key, parent::get( $key ) );
        }

        public function set( $key, $value, $exptime = 0 ) {
                $this->debugLog( "set($key)" );
                return $this->checkResult( $key, parent::set( $key, $value, $exptime ) );
        }

        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 );
                }
        }

        public function add( $key, $value, $exptime = 0 ) {
                $this->debugLog( "add($key)" );
                return $this->checkResult( $key, parent::add( $key, $value, $exptime ) );
        }

        public function replace( $key, $value, $exptime = 0 ) {
                $this->debugLog( "replace($key)" );
                return $this->checkResult( $key, parent::replace( $key, $value, $exptime ) );
        }

        public function incr( $key, $value = 1 ) {
                $this->debugLog( "incr($key)" );
                $result = $this->client->increment( $key, $value );
                return $this->checkResult( $key, $result );
        }

        public function decr( $key, $value = 1 ) {
                $this->debugLog( "decr($key)" );
                $result = $this->client->decrement( $key, $value );
                return $this->checkResult( $key, $result );
        }

        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;
        }

        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.
         */
}