JobQueueAggregatorRedis.php

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<?php
class JobQueueAggregatorRedis extends JobQueueAggregator {
    protected $redisPool;

    protected $servers;

    protected function __construct( array $params ) {
        parent::__construct( $params );
        $this->servers = isset( $params['redisServers'] )
            ? $params['redisServers']
            : array( $params['redisServer'] ); // b/c
        $params['redisConfig']['serializer'] = 'none';
        $this->redisPool = RedisConnectionPool::singleton( $params['redisConfig'] );
    }

    protected function doNotifyQueueEmpty( $wiki, $type ) {
        $conn = $this->getConnection();
        if ( !$conn ) {
            return false;
        }
        try {
            $conn->hDel( $this->getReadyQueueKey(), $this->encQueueName( $type, $wiki ) );

            return true;
        } catch ( RedisException $e ) {
            $this->handleException( $conn, $e );

            return false;
        }
    }

    protected function doNotifyQueueNonEmpty( $wiki, $type ) {
        $conn = $this->getConnection();
        if ( !$conn ) {
            return false;
        }
        try {
            $conn->multi( Redis::PIPELINE );
            $conn->hSetNx( $this->getQueueTypesKey(), $type, 'enabled' );
            $conn->hSet( $this->getReadyQueueKey(), $this->encQueueName( $type, $wiki ), time() );
            $conn->exec();

            return true;
        } catch ( RedisException $e ) {
            $this->handleException( $conn, $e );

            return false;
        }
    }

    protected function doGetAllReadyWikiQueues() {
        $conn = $this->getConnection();
        if ( !$conn ) {
            return array();
        }
        try {
            $map = $conn->hGetAll( $this->getReadyQueueKey() );

            if ( is_array( $map ) && isset( $map['_epoch'] ) ) {
                unset( $map['_epoch'] ); // ignore
                $pendingDBs = array(); // (type => list of wikis)
                foreach ( $map as $key => $time ) {
                    list( $type, $wiki ) = $this->dencQueueName( $key );
                    $pendingDBs[$type][] = $wiki;
                }
            } else {
                // Avoid duplicated effort
                $rand = wfRandomString( 32 );
                $conn->multi( Redis::MULTI );
                $conn->setex( "{$rand}:lock", 3600, 1 );
                $conn->renamenx( "{$rand}:lock", $this->getReadyQueueKey() . ":lock" );
                if ( $conn->exec() !== array( true, true ) ) { // lock
                    $conn->delete( "{$rand}:lock" );
                    return array(); // already in progress
                }

                $pendingDBs = $this->findPendingWikiQueues(); // (type => list of wikis)

                $conn->multi( Redis::PIPELINE );
                $now = time();
                $map = array( '_epoch' => time() ); // dummy key for empty Redis collections
                foreach ( $pendingDBs as $type => $wikis ) {
                    $conn->hSetNx( $this->getQueueTypesKey(), $type, 'enabled' );
                    foreach ( $wikis as $wiki ) {
                        $map[$this->encQueueName( $type, $wiki )] = $now;
                    }
                }
                $conn->hMSet( $this->getReadyQueueKey(), $map );
                $conn->exec();

                $conn->delete( $this->getReadyQueueKey() . ":lock" ); // unlock
            }

            return $pendingDBs;
        } catch ( RedisException $e ) {
            $this->handleException( $conn, $e );

            return array();
        }
    }

    protected function doPurge() {
        $conn = $this->getConnection();
        if ( !$conn ) {
            return false;
        }
        try {
            $conn->delete( $this->getReadyQueueKey() );
            // leave key at getQueueTypesKey() alone
        } catch ( RedisException $e ) {
            $this->handleException( $conn, $e );

            return false;
        }

        return true;
    }

    protected function getConnection() {
        $conn = false;
        foreach ( $this->servers as $server ) {
            $conn = $this->redisPool->getConnection( $server );
            if ( $conn ) {
                break;
            }
        }

        return $conn;
    }

    protected function handleException( RedisConnRef $conn, $e ) {
        $this->redisPool->handleError( $conn, $e );
    }

    private function getReadyQueueKey() {
        return "jobqueue:aggregator:h-ready-queues:v2"; // global
    }

    private function getQueueTypesKey() {
        return "jobqueue:aggregator:h-queue-types:v2"; // global
    }

    private function encQueueName( $type, $wiki ) {
        return rawurlencode( $type ) . '/' . rawurlencode( $wiki );
    }

    private function dencQueueName( $name ) {
        list( $type, $wiki ) = explode( '/', $name, 2 );

        return array( rawurldecode( $type ), rawurldecode( $wiki ) );
    }
}