ObjectCacheFactory.php

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<?php
use MediaWiki\Config\ServiceOptions;
use MediaWiki\Deferred\DeferredUpdates;
use MediaWiki\Http\Telemetry;
use MediaWiki\Logger\Spi;
use MediaWiki\MainConfigNames;
use MediaWiki\MediaWikiServices;
use Wikimedia\ObjectCache\APCUBagOStuff;
use Wikimedia\ObjectCache\BagOStuff;
use Wikimedia\ObjectCache\EmptyBagOStuff;
use Wikimedia\ObjectCache\HashBagOStuff;
use Wikimedia\ObjectCache\MemcachedBagOStuff;
use Wikimedia\ObjectCache\MultiWriteBagOStuff;
use Wikimedia\ObjectCache\RESTBagOStuff;
use Wikimedia\ObjectCache\WinCacheBagOStuff;
use Wikimedia\Stats\StatsFactory;
 
class ObjectCacheFactory {
    public const CONSTRUCTOR_OPTIONS = [
        MainConfigNames::SQLiteDataDir,
        MainConfigNames::UpdateRowsPerQuery,
        MainConfigNames::MemCachedServers,
        MainConfigNames::MemCachedPersistent,
        MainConfigNames::MemCachedTimeout,
        MainConfigNames::CachePrefix,
        MainConfigNames::ObjectCaches,
        MainConfigNames::MainCacheType,
        MainConfigNames::MessageCacheType,
        MainConfigNames::ParserCacheType,
    ];
 
    private ServiceOptions $options;
    private StatsFactory $stats;
    private Spi $logger;
    private $instances = [];
    private string $domainId;
    private $dbLoadBalancerFactory;
    public static $localServerCacheClass;
 
    public function __construct(
        ServiceOptions $options,
        StatsFactory $stats,
        Spi $loggerSpi,
        callable $dbLoadBalancerFactory,
        string $domainId
    ) {
        $options->assertRequiredOptions( self::CONSTRUCTOR_OPTIONS );
        $this->options = $options;
        $this->stats = $stats;
        $this->logger = $loggerSpi;
        $this->dbLoadBalancerFactory = $dbLoadBalancerFactory;
        $this->domainId = $domainId;
    }
 
    private function getDefaultKeyspace(): string {
        $cachePrefix = $this->options->get( MainConfigNames::CachePrefix );
        if ( is_string( $cachePrefix ) && $cachePrefix !== '' ) {
            return $cachePrefix;
        }
 
        return $this->domainId;
    }
 
    private function newFromId( $id ): BagOStuff {
        if ( $id === CACHE_ANYTHING ) {
            $id = $this->getAnythingId();
        }
 
        if ( !isset( $this->options->get( MainConfigNames::ObjectCaches )[$id] ) ) {
            // Always recognize these
            if ( $id === CACHE_NONE ) {
                return new EmptyBagOStuff();
            } elseif ( $id === CACHE_HASH ) {
                return new HashBagOStuff();
            } elseif ( $id === CACHE_ACCEL ) {
                return self::makeLocalServerCache( $this->getDefaultKeyspace() );
            }
 
            throw new InvalidArgumentException( "Invalid object cache type \"$id\" requested. " .
                "It is not present in \$wgObjectCaches." );
        }
 
        return $this->newFromParams( $this->options->get( MainConfigNames::ObjectCaches )[$id] );
    }
 
    public function getInstance( $id ): BagOStuff {
        if ( !isset( $this->instances[$id] ) ) {
            $this->instances[$id] = $this->newFromId( $id );
        }
 
        return $this->instances[$id];
    }
 
    public function newFromParams( array $params ): BagOStuff {
        $logger = $this->logger->getLogger( $params['loggroup'] ?? 'objectcache' );
        // Apply default parameters and resolve the logger instance
        $params += [
            'logger' => $logger,
            'keyspace' => $this->getDefaultKeyspace(),
            'asyncHandler' => [ DeferredUpdates::class, 'addCallableUpdate' ],
            'reportDupes' => true,
            'stats' => $this->stats,
        ];
 
        if ( isset( $params['factory'] ) ) {
            $args = $params['args'] ?? [ $params ];
 
            return call_user_func( $params['factory'], ...$args );
        }
 
        if ( !isset( $params['class'] ) ) {
            throw new InvalidArgumentException(
                'No "factory" nor "class" provided; got "' . print_r( $params, true ) . '"'
            );
        }
 
        $class = $params['class'];
 
        // Normalization and DI for SqlBagOStuff
        if ( is_a( $class, SqlBagOStuff::class, true ) ) {
            $this->prepareSqlBagOStuffFromParams( $params );
        }
 
        // Normalization and DI for MemcachedBagOStuff
        if ( is_subclass_of( $class, MemcachedBagOStuff::class ) ) {
            $this->prepareMemcachedBagOStuffFromParams( $params );
        }
 
        // Normalization and DI for MultiWriteBagOStuff
        if ( is_a( $class, MultiWriteBagOStuff::class, true ) ) {
            $this->prepareMultiWriteBagOStuffFromParams( $params );
        }
        if ( is_a( $class, RESTBagOStuff::class, true ) ) {
            $this->prepareRESTBagOStuffFromParams( $params );
        }
 
        return new $class( $params );
    }
 
    private function prepareSqlBagOStuffFromParams( array &$params ): void {
        if ( isset( $params['globalKeyLB'] ) ) {
            throw new InvalidArgumentException(
                'globalKeyLB in $wgObjectCaches is no longer supported' );
        }
        if ( isset( $params['server'] ) && !isset( $params['servers'] ) ) {
            $params['servers'] = [ $params['server'] ];
            unset( $params['server'] );
        }
        if ( isset( $params['servers'] ) ) {
            // In the past it was not required to set 'dbDirectory' in $wgObjectCaches
            foreach ( $params['servers'] as &$server ) {
                if ( $server['type'] === 'sqlite' && !isset( $server['dbDirectory'] ) ) {
                    $server['dbDirectory'] = $this->options->get( MainConfigNames::SQLiteDataDir );
                }
            }
        } elseif ( isset( $params['cluster'] ) ) {
            $cluster = $params['cluster'];
            $dbLbFactory = $this->dbLoadBalancerFactory;
            $params['loadBalancerCallback'] = static function () use ( $cluster, $dbLbFactory ) {
                return $dbLbFactory()->getExternalLB( $cluster );
            };
            $params += [ 'dbDomain' => false ];
        } else {
            $dbLbFactory = $this->dbLoadBalancerFactory;
            $params['loadBalancerCallback'] = static function () use ( $dbLbFactory ) {
                return $dbLbFactory()->getMainLb();
            };
            $params += [ 'dbDomain' => false ];
        }
        $params += [ 'writeBatchSize' => $this->options->get( MainConfigNames::UpdateRowsPerQuery ) ];
    }
 
    private function prepareMemcachedBagOStuffFromParams( array &$params ): void {
        $params += [
            'servers' => $this->options->get( MainConfigNames::MemCachedServers ),
            'persistent' => $this->options->get( MainConfigNames::MemCachedPersistent ),
            'timeout' => $this->options->get( MainConfigNames::MemCachedTimeout ),
        ];
    }
 
    private function prepareMultiWriteBagOStuffFromParams( array &$params ): void {
        // Phan warns about foreach with non-array because it
        // thinks any key can be Closure|IBufferingStatsdDataFactory
        '@phan-var array{caches:array[]} $params';
        foreach ( $params['caches'] ?? [] as $i => $cacheInfo ) {
            // Ensure logger, keyspace, asyncHandler, etc are injected just as if
            // one of these was configured without MultiWriteBagOStuff.
            $params['caches'][$i] = $this->newFromParams( $cacheInfo );
        }
    }
 
    private function prepareRESTBagOStuffFromParams( array &$params ): void {
        $params['telemetry'] = Telemetry::getInstance();
    }
 
    public function getLocalServerInstance( $fallback = CACHE_NONE ): BagOStuff {
        $cache = $this->getInstance( CACHE_ACCEL );
        if ( $cache instanceof EmptyBagOStuff ) {
            if ( is_array( $fallback ) ) {
                $fallback = $fallback['fallback'] ?? CACHE_NONE;
            }
            $cache = $this->getInstance( $fallback );
        }
 
        return $cache;
    }
 
    public function clear(): void {
        $this->instances = [];
    }
 
    private static function getLocalServerCacheClass() {
        if ( self::$localServerCacheClass !== null ) {
            return self::$localServerCacheClass;
        }
        if ( function_exists( 'apcu_fetch' ) ) {
            // Make sure the APCu methods actually store anything
            if ( PHP_SAPI !== 'cli' || ini_get( 'apc.enable_cli' ) ) {
                return APCUBagOStuff::class;
 
            }
        } elseif ( function_exists( 'wincache_ucache_get' ) ) {
            return WinCacheBagOStuff::class;
        }
 
        return EmptyBagOStuff::class;
    }
 
    public function getAnythingId() {
        $candidates = [
            $this->options->get( MainConfigNames::MainCacheType ),
            $this->options->get( MainConfigNames::MessageCacheType ),
            $this->options->get( MainConfigNames::ParserCacheType )
        ];
        foreach ( $candidates as $candidate ) {
            if ( $candidate === CACHE_ACCEL ) {
                // CACHE_ACCEL might default to nothing if no APCu
                // See includes/ServiceWiring.php
                $class = self::getLocalServerCacheClass();
                if ( $class !== EmptyBagOStuff::class ) {
                    return $candidate;
                }
            } elseif ( $candidate !== CACHE_NONE && $candidate !== CACHE_ANYTHING ) {
                return $candidate;
            }
        }
 
        $services = MediaWikiServices::getInstance();
 
        if ( $services->isServiceDisabled( 'DBLoadBalancer' ) ) {
            // The DBLoadBalancer service is disabled, so we can't use the database!
            $candidate = CACHE_NONE;
        } elseif ( $services->isStorageDisabled() ) {
            // Storage services are disabled because MediaWikiServices::disableStorage()
            // was called. This is typically the case during installation.
            $candidate = CACHE_NONE;
        } else {
            $candidate = CACHE_DB;
        }
        return $candidate;
    }
 
    public static function makeLocalServerCache( string $keyspace ) {
        $params = [
            'reportDupes' => false,
            // Even simple caches must use a keyspace (T247562)
            'keyspace' => $keyspace,
        ];
        $class = self::getLocalServerCacheClass();
        return new $class( $params );
    }
 
    public function isDatabaseId( $id ) {
        // NOTE: Sanity check if $id is set to CACHE_ANYTHING and
        // everything is going through service wiring. CACHE_ANYTHING
        // would default to CACHE_DB, let's handle that early for cases
        // where all cache configs are set to CACHE_ANYTHING (T362686).
        if ( $id === CACHE_ANYTHING ) {
            $id = $this->getAnythingId();
            return $this->isDatabaseId( $id );
        }
 
        if ( !isset( $this->options->get( MainConfigNames::ObjectCaches )[$id] ) ) {
            return false;
        }
        $cache = $this->options->get( MainConfigNames::ObjectCaches )[$id];
        if ( ( $cache['class'] ?? '' ) === SqlBagOStuff::class ) {
            return true;
        }
 
        return false;
    }
 
    public function getLocalClusterInstance() {
        return $this->getInstance(
            $this->options->get( MainConfigNames::MainCacheType )
        );
    }
}