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 reuse 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';
        }

        if ( isset( $params['retry_timeout'] ) ) {
            $this->client->setOption( Memcached::OPT_RETRY_TIMEOUT, $params['retry_timeout'] );
        }

        if ( isset( $params['server_failure_limit'] ) ) {
            $this->client->setOption( Memcached::OPT_SERVER_FAILURE_LIMIT, $params['server_failure_limit'] );
        }

        // 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( $key, &$casToken = null ) {
        wfProfileIn( __METHOD__ );
        $this->debugLog( "get($key)" );
        $result = $this->client->get( $this->encodeKey( $key ), null, $casToken );
        $result = $this->checkResult( $key, $result );
        wfProfileOut( __METHOD__ );
        return $result;
    }

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

    public function cas( $casToken, $key, $value, $exptime = 0 ) {
        $this->debugLog( "cas($key)" );
        return $this->checkResult( $key, parent::cas( $casToken, $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 ) {
        wfProfileIn( __METHOD__ );
        $this->debugLog( 'getMulti(' . implode( ', ', $keys ) . ')' );
        $callback = array( $this, 'encodeKey' );
        $result = $this->client->getMulti( array_map( $callback, $keys ) );
        wfProfileOut( __METHOD__ );
        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.
     */
}