ObjectCache.php

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<?php
use MediaWiki\Deferred\DeferredUpdates;
use MediaWiki\Http\Telemetry;
use MediaWiki\Logger\LoggerFactory;
use MediaWiki\MainConfigNames;
use MediaWiki\MediaWikiServices;
use MediaWiki\WikiMap\WikiMap;
 
class ObjectCache {
    public static $instances = [];
 
    public static $localServerCacheClass;
 
    public static function getInstance( $id ) {
        if ( !isset( self::$instances[$id] ) ) {
            self::$instances[$id] = self::newFromId( $id );
        }
 
        return self::$instances[$id];
    }
 
    private static function newFromId( $id ) {
        global $wgObjectCaches;
 
        if ( !isset( $wgObjectCaches[$id] ) ) {
            // Always recognize these ones
            if ( $id === CACHE_NONE ) {
                return new EmptyBagOStuff();
            } elseif ( $id === CACHE_HASH ) {
                return new HashBagOStuff();
            }
 
            throw new InvalidArgumentException( "Invalid object cache type \"$id\" requested. " .
                "It is not present in \$wgObjectCaches." );
        }
 
        return self::newFromParams( $wgObjectCaches[$id] );
    }
 
    private static function getDefaultKeyspace() {
        global $wgCachePrefix;
 
        $keyspace = $wgCachePrefix;
        if ( is_string( $keyspace ) && $keyspace !== '' ) {
            return $keyspace;
        }
 
        return WikiMap::getCurrentWikiDbDomain()->getId();
    }
 
    public static function newFromParams( array $params, MediaWikiServices $services = null ) {
        $services ??= MediaWikiServices::getInstance();
        $conf = $services->getMainConfig();
 
        // Apply default parameters and resolve the logger instance
        $params += [
            'logger' => LoggerFactory::getInstance( $params['loggroup'] ?? 'objectcache' ),
            'keyspace' => self::getDefaultKeyspace(),
            'asyncHandler' => [ DeferredUpdates::class, 'addCallableUpdate' ],
            'reportDupes' => true,
            'stats' => $services->getStatsdDataFactory(),
        ];
 
        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 ) ) {
            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'] = $conf->get( MainConfigNames::SQLiteDataDir );
                    }
                }
            } elseif ( isset( $params['cluster'] ) ) {
                $cluster = $params['cluster'];
                $params['loadBalancerCallback'] = static function () use ( $services, $cluster ) {
                    return $services->getDBLoadBalancerFactory()->getExternalLB( $cluster );
                };
                $params += [ 'dbDomain' => false ];
            } else {
                $params['loadBalancerCallback'] = static function () use ( $services ) {
                    return $services->getDBLoadBalancer();
                };
                $params += [ 'dbDomain' => false ];
            }
            $params += [ 'writeBatchSize' => $conf->get( MainConfigNames::UpdateRowsPerQuery ) ];
        }
 
        // Normalization and DI for MemcachedBagOStuff
        if ( is_subclass_of( $class, MemcachedBagOStuff::class ) ) {
            $params += [
                'servers' => $conf->get( MainConfigNames::MemCachedServers ),
                'persistent' => $conf->get( MainConfigNames::MemCachedPersistent ),
                'timeout' => $conf->get( MainConfigNames::MemCachedTimeout ),
            ];
        }
 
        // Normalization and DI for MultiWriteBagOStuff
        if ( is_a( $class, MultiWriteBagOStuff::class, true ) ) {
            // 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] = self::newFromParams( $cacheInfo, $services );
            }
        }
        if ( is_a( $class, RESTBagOStuff::class, true ) ) {
            $params['telemetry'] = Telemetry::getInstance();
        }
 
        return new $class( $params );
    }
 
    public static function newAnything( $params ) {
        return self::getInstance( self::getAnythingId() );
    }
 
    private static function getAnythingId() {
        global $wgMainCacheType, $wgMessageCacheType, $wgParserCacheType;
        $candidates = [ $wgMainCacheType, $wgMessageCacheType, $wgParserCacheType ];
        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 getLocalServerInstance( $fallback = CACHE_NONE ) {
        $cache = MediaWikiServices::getInstance()->getLocalServerObjectCache();
        if ( $cache instanceof EmptyBagOStuff ) {
            if ( is_array( $fallback ) ) {
                $fallback = $fallback['fallback'] ?? CACHE_NONE;
            }
            $cache = self::getInstance( $fallback );
        }
 
        return $cache;
    }
 
    public static function getLocalClusterInstance() {
        return MediaWikiServices::getInstance()->get( '_LocalClusterCache' );
    }
 
    public static function isDatabaseId( $id ) {
        global $wgObjectCaches;
        if ( !isset( $wgObjectCaches[$id] ) ) {
            return false;
        }
        $cache = $wgObjectCaches[$id];
        if ( ( $cache['class'] ?? '' ) === SqlBagOStuff::class ) {
            return true;
        }
        // Ideally we would inspect the config, but it's complicated. The ID is suggestive.
        if ( $id === 'db-replicated' ) {
            return true;
        }
        if ( ( $cache['factory'] ?? '' ) === 'ObjectCache::newAnything' ) {
            $id = self::getAnythingId();
            return self::isDatabaseId( $id );
        }
        return false;
    }
 
    public static function clear() {
        self::$instances = [];
    }
 
    public static function makeLocalServerCache(): BagOStuff {
        $params = [
            'reportDupes' => false,
            // Even simple caches must use a keyspace (T247562)
            'keyspace' => self::getDefaultKeyspace(),
        ];
        $class = self::getLocalServerCacheClass();
        return new $class( $params );
    }
 
    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;
    }
}