BloomCache.php

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<?php
abstract class BloomCache {
    protected $cacheID;

    protected static $instances = array();

    final public static function get( $id ) {
        global $wgBloomFilterStores;

        if ( !isset( self::$instances[$id] ) ) {
            if ( isset( $wgBloomFilterStores[$id] ) ) {
                $class = $wgBloomFilterStores[$id]['class'];
                self::$instances[$id] = new $class( $wgBloomFilterStores[$id] );
            } else {
                wfDebug( "No bloom filter store '$id'; using EmptyBloomCache." );
                return new EmptyBloomCache( array() );
            }
        }

        return self::$instances[$id];
    }

    public function __construct( array $config ) {
        $this->cacheID = $config['cacheId'];
        if ( !preg_match( '!^[a-zA-Z0-9-_]{1,32}$!', $this->cacheID ) ) {
            throw new MWException( "Cache ID '{$this->cacheID}' is invalid." );
        }
    }

    final public function check( $domain, $type, $member ) {
        $section = new ProfileSection( get_class( $this ) . '::' . __FUNCTION__ );

        if ( method_exists( "BloomFilter{$type}", 'mergeAndCheck' ) ) {
            try {
                $virtualKey = "$domain:$type";

                $status = $this->getStatus( $virtualKey );
                if ( $status == false ) {
                    wfDebug( "Could not query virtual bloom filter '$virtualKey'." );
                    return null;
                }

                $useFilter = call_user_func_array(
                    array( "BloomFilter{$type}", 'mergeAndCheck' ),
                    array( $this, $domain, $virtualKey, $status )
                );

                if ( $useFilter ) {
                    return ( $this->isHit( 'shared', "$virtualKey:$member" ) !== false );
                }
            } catch ( MWException $e ) {
                MWExceptionHandler::logException( $e );
                return true;
            }
        }

        return true;
    }

    final public function insert( $domain, $type, $members ) {
        $section = new ProfileSection( get_class( $this ) . '::' . __FUNCTION__ );

        if ( method_exists( "BloomFilter{$type}", 'mergeAndCheck' ) ) {
            try {
                $virtualKey = "$domain:$type";
                $prefixedMembers = array();
                foreach ( (array)$members as $member ) {
                    $prefixedMembers[] = "$virtualKey:$member";
                }

                return $this->add( 'shared', $prefixedMembers );
            } catch ( MWException $e ) {
                MWExceptionHandler::logException( $e );
                return false;
            }
        }

        return true;
    }

    final public function init( $key, $size = 1000000, $precision = .001 ) {
        $section = new ProfileSection( get_class( $this ) . '::' . __FUNCTION__ );

        return $this->doInit( "{$this->cacheID}:$key", $size, min( .1, $precision ) );
    }

    final public function add( $key, $members ) {
        $section = new ProfileSection( get_class( $this ) . '::' . __FUNCTION__ );

        return $this->doAdd( "{$this->cacheID}:$key", (array)$members );
    }

    final public function isHit( $key, $member ) {
        $section = new ProfileSection( get_class( $this ) . '::' . __FUNCTION__ );

        return $this->doIsHit( "{$this->cacheID}:$key", $member );
    }

    final public function delete( $key ) {
        $section = new ProfileSection( get_class( $this ) . '::' . __FUNCTION__ );

        return $this->doDelete( "{$this->cacheID}:$key" );
    }

    final public function setStatus( $virtualKey, array $values ) {
        $section = new ProfileSection( get_class( $this ) . '::' . __FUNCTION__ );

        return $this->doSetStatus( "{$this->cacheID}:$virtualKey", $values );
    }

    final public function getStatus( $virtualKey ) {
        $section = new ProfileSection( get_class( $this ) . '::' . __FUNCTION__ );

        return $this->doGetStatus( "{$this->cacheID}:$virtualKey" );
    }

    public function getScopedLock( $virtualKey ) {
        return null;
    }

    abstract protected function doInit( $key, $size, $precision );

    abstract protected function doAdd( $key, array $members );

    abstract protected function doIsHit( $key, $member );

    abstract protected function doDelete( $key );

    abstract protected function doSetStatus( $virtualKey, array $values );

    abstract protected function doGetStatus( $key );
}

class EmptyBloomCache extends BloomCache {
    public function __construct( array $config ) {
        parent::__construct( array( 'cacheId' => 'none' ) );
    }

    protected function doInit( $key, $size, $precision ) {
        return true;
    }

    protected function doAdd( $key, array $members ) {
        return true;
    }

    protected function doIsHit( $key, $member ) {
        return true;
    }

    protected function doDelete( $key ) {
        return true;
    }

    protected function doSetStatus( $virtualKey, array $values ) {
        return true;
    }

    protected function doGetStatus( $virtualKey ) {
        return array( 'lastID' => null, 'asOfTime' => null, 'epoch' => null ) ;
    }
}