ObjectCache.php

Go to the documentation of this file.

<?php
use MediaWiki\Logger\LoggerFactory;
use MediaWiki\MainConfigNames;
use MediaWiki\MediaWikiServices;
 
class ObjectCache {
    public static $instances = [];
 
    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, Config $conf = null ) {
        $services = MediaWikiServices::getInstance();
        // 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'];
        $conf ??= $services->getMainConfig();
 
        // 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, $conf );
            }
        }
 
        return new $class( $params );
    }
 
    public static function newAnything( $params ) {
        global $wgMainCacheType, $wgMessageCacheType, $wgParserCacheType;
        $candidates = [ $wgMainCacheType, $wgMessageCacheType, $wgParserCacheType ];
        foreach ( $candidates as $candidate ) {
            if ( $candidate !== CACHE_NONE && $candidate !== CACHE_ANYTHING ) {
                $cache = self::getInstance( $candidate );
                // CACHE_ACCEL might default to nothing if no APCu
                // See includes/ServiceWiring.php
                if ( !( $cache instanceof EmptyBagOStuff ) ) {
                    return $cache;
                }
            }
        }
 
        if ( MediaWikiServices::getInstance()->isServiceDisabled( 'DBLoadBalancer' ) ) {
            // The LoadBalancer is disabled, probably because
            // MediaWikiServices::disableStorageBackend was called.
            $candidate = CACHE_NONE;
        } else {
            $candidate = CACHE_DB;
        }
 
        return self::getInstance( $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() {
        global $wgMainCacheType;
 
        return self::getInstance( $wgMainCacheType );
    }
 
    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(),
        ];
        if ( function_exists( 'apcu_fetch' ) ) {
            // Make sure the APCu methods actually store anything
            if ( PHP_SAPI !== 'cli' || ini_get( 'apc.enable_cli' ) ) {
                return new APCUBagOStuff( $params );
            }
        } elseif ( function_exists( 'wincache_ucache_get' ) ) {
            return new WinCacheBagOStuff( $params );
        }
 
        return new EmptyBagOStuff( $params );
    }
}