Move ILoadBalancer to Rdbms namespace

[mediawiki.git] / includes / db / MWLBFactory.php

<?php
/**
 * Generator of database load balancing objects.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * http://www.gnu.org/copyleft/gpl.html
 *
 * @file
 * @ingroup Database
 */

use MediaWiki\Logger\LoggerFactory;
use MediaWiki\MediaWikiServices;
use Wikimedia\Rdbms\DatabaseDomain;

/**
 * MediaWiki-specific class for generating database load balancers
 * @ingroup Database
 */
abstract class MWLBFactory {
        /**
         * @param array $lbConf Config for LBFactory::__construct()
         * @param Config $mainConfig Main config object from MediaWikiServices
         * @return array
         */
        public static function applyDefaultConfig( array $lbConf, Config $mainConfig ) {
                global $wgCommandLineMode;

                static $typesWithSchema = [ 'postgres', 'msssql' ];

                $lbConf += [
                        'localDomain' => new DatabaseDomain(
                                $mainConfig->get( 'DBname' ),
                                null,
                                $mainConfig->get( 'DBprefix' )
                        ),
                        'profiler' => Profiler::instance(),
                        'trxProfiler' => Profiler::instance()->getTransactionProfiler(),
                        'replLogger' => LoggerFactory::getInstance( 'DBReplication' ),
                        'queryLogger' => LoggerFactory::getInstance( 'DBQuery' ),
                        'connLogger' => LoggerFactory::getInstance( 'DBConnection' ),
                        'perfLogger' => LoggerFactory::getInstance( 'DBPerformance' ),
                        'errorLogger' => [ MWExceptionHandler::class, 'logException' ],
                        'cliMode' => $wgCommandLineMode,
                        'hostname' => wfHostname(),
                        // TODO: replace the global wfConfiguredReadOnlyReason() with a service.
                        'readOnlyReason' => wfConfiguredReadOnlyReason(),
                ];

                if ( $lbConf['class'] === 'LBFactorySimple' ) {
                        if ( isset( $lbConf['servers'] ) ) {
                                // Server array is already explicitly configured; leave alone
                        } elseif ( is_array( $mainConfig->get( 'DBservers' ) ) ) {
                                foreach ( $mainConfig->get( 'DBservers' ) as $i => $server ) {
                                        if ( $server['type'] === 'sqlite' ) {
                                                $server += [ 'dbDirectory' => $mainConfig->get( 'SQLiteDataDir' ) ];
                                        } elseif ( $server['type'] === 'postgres' ) {
                                                $server += [
                                                        'port' => $mainConfig->get( 'DBport' ),
                                                        // Work around the reserved word usage in MediaWiki schema
                                                        'keywordTableMap' => [ 'user' => 'mwuser', 'text' => 'pagecontent' ]
                                                ];
                                        }
                                        if ( in_array( $server['type'], $typesWithSchema, true ) ) {
                                                $server += [ 'schema' => $mainConfig->get( 'DBmwschema' ) ];
                                        }

                                        $server += [
                                                'tablePrefix' => $mainConfig->get( 'DBprefix' ),
                                                'flags' => DBO_DEFAULT,
                                                'sqlMode' => $mainConfig->get( 'SQLMode' ),
                                                'utf8Mode' => $mainConfig->get( 'DBmysql5' )
                                        ];

                                        $lbConf['servers'][$i] = $server;
                                }
                        } else {
                                $flags = DBO_DEFAULT;
                                $flags |= $mainConfig->get( 'DebugDumpSql' ) ? DBO_DEBUG : 0;
                                $flags |= $mainConfig->get( 'DBssl' ) ? DBO_SSL : 0;
                                $flags |= $mainConfig->get( 'DBcompress' ) ? DBO_COMPRESS : 0;
                                $server = [
                                        'host' => $mainConfig->get( 'DBserver' ),
                                        'user' => $mainConfig->get( 'DBuser' ),
                                        'password' => $mainConfig->get( 'DBpassword' ),
                                        'dbname' => $mainConfig->get( 'DBname' ),
                                        'tablePrefix' => $mainConfig->get( 'DBprefix' ),
                                        'type' => $mainConfig->get( 'DBtype' ),
                                        'load' => 1,
                                        'flags' => $flags,
                                        'sqlMode' => $mainConfig->get( 'SQLMode' ),
                                        'utf8Mode' => $mainConfig->get( 'DBmysql5' )
                                ];
                                if ( in_array( $server['type'], $typesWithSchema, true ) ) {
                                        $server += [ 'schema' => $mainConfig->get( 'DBmwschema' ) ];
                                }
                                if ( $server['type'] === 'sqlite' ) {
                                        $server[ 'dbDirectory'] = $mainConfig->get( 'SQLiteDataDir' );
                                } elseif ( $server['type'] === 'postgres' ) {
                                        $server['port'] = $mainConfig->get( 'DBport' );
                                        // Work around the reserved word usage in MediaWiki schema
                                        $server['keywordTableMap'] = [ 'user' => 'mwuser', 'text' => 'pagecontent' ];
                                }
                                $lbConf['servers'] = [ $server ];
                        }
                        if ( !isset( $lbConf['externalClusters'] ) ) {
                                $lbConf['externalClusters'] = $mainConfig->get( 'ExternalServers' );
                        }
                } elseif ( $lbConf['class'] === 'LBFactoryMulti' ) {
                        if ( isset( $lbConf['serverTemplate'] ) ) {
                                if ( in_array( $lbConf['serverTemplate']['type'], $typesWithSchema, true ) ) {
                                        $lbConf['serverTemplate']['schema'] = $mainConfig->get( 'DBmwschema' );
                                }
                                $lbConf['serverTemplate']['sqlMode'] = $mainConfig->get( 'SQLMode' );
                                $lbConf['serverTemplate']['utf8Mode'] = $mainConfig->get( 'DBmysql5' );
                        }
                }

                // Use APC/memcached style caching, but avoids loops with CACHE_DB (T141804)
                $sCache = MediaWikiServices::getInstance()->getLocalServerObjectCache();
                if ( $sCache->getQoS( $sCache::ATTR_EMULATION ) > $sCache::QOS_EMULATION_SQL ) {
                        $lbConf['srvCache'] = $sCache;
                }
                $cCache = ObjectCache::getLocalClusterInstance();
                if ( $cCache->getQoS( $cCache::ATTR_EMULATION ) > $cCache::QOS_EMULATION_SQL ) {
                        $lbConf['memCache'] = $cCache;
                }
                $wCache = MediaWikiServices::getInstance()->getMainWANObjectCache();
                if ( $wCache->getQoS( $wCache::ATTR_EMULATION ) > $wCache::QOS_EMULATION_SQL ) {
                        $lbConf['wanCache'] = $wCache;
                }

                return $lbConf;
        }

        /**
         * Returns the LBFactory class to use and the load balancer configuration.
         *
         * @todo instead of this, use a ServiceContainer for managing the different implementations.
         *
         * @param array $config (e.g. $wgLBFactoryConf)
         * @return string Class name
         */
        public static function getLBFactoryClass( array $config ) {
                // For configuration backward compatibility after removing
                // underscores from class names in MediaWiki 1.23.
                $bcClasses = [
                        'LBFactory_Simple' => 'LBFactorySimple',
                        'LBFactory_Single' => 'LBFactorySingle',
                        'LBFactory_Multi' => 'LBFactoryMulti'
                ];

                $class = $config['class'];

                if ( isset( $bcClasses[$class] ) ) {
                        $class = $bcClasses[$class];
                        wfDeprecated(
                                '$wgLBFactoryConf must be updated. See RELEASE-NOTES for details',
                                '1.23'
                        );
                }

                // For configuration backward compatibility after moving classes to namespaces (1.29)
                $compat = [
                        'LBFactorySingle' => Wikimedia\Rdbms\LBFactorySingle::class,
                        'LBFactorySimple' => Wikimedia\Rdbms\LBFactorySimple::class,
                        'LBFactoryMulti' => Wikimedia\Rdbms\LBFactoryMulti::class
                ];

                if ( isset( $compat[$class] ) ) {
                        $class = $compat[$class];
                }

                return $class;
        }
}