MWLBFactory.php

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<?php
use Liuggio\StatsdClient\Factory\StatsdDataFactoryInterface;
use MediaWiki\Config\Config;
use MediaWiki\Config\ServiceOptions;
use MediaWiki\Logger\LoggerFactory;
use MediaWiki\MainConfigNames;
use Wikimedia\Rdbms\ChronologyProtector;
use Wikimedia\Rdbms\ConfiguredReadOnlyMode;
use Wikimedia\Rdbms\DatabaseDomain;
use Wikimedia\Rdbms\IDatabase;
use Wikimedia\Rdbms\ILBFactory;
use Wikimedia\RequestTimeout\CriticalSectionProvider;
 
class MWLBFactory {
 
    private static $loggedDeprecations = [];
 
    public const APPLY_DEFAULT_CONFIG_OPTIONS = [
        'CommandLineMode',
        MainConfigNames::DBcompress,
        MainConfigNames::DBDefaultGroup,
        MainConfigNames::DBmwschema,
        MainConfigNames::DBname,
        MainConfigNames::DBpassword,
        MainConfigNames::DBport,
        MainConfigNames::DBprefix,
        MainConfigNames::DBserver,
        MainConfigNames::DBservers,
        MainConfigNames::DBssl,
        MainConfigNames::DBtype,
        MainConfigNames::DBuser,
        MainConfigNames::DebugDumpSql,
        MainConfigNames::DebugLogFile,
        MainConfigNames::DebugToolbar,
        MainConfigNames::ExternalServers,
        MainConfigNames::SQLiteDataDir,
        MainConfigNames::SQLMode,
        MainConfigNames::VirtualDomainsMapping,
    ];
    private $options;
    private $readOnlyMode;
    private $chronologyProtector;
    private $srvCache;
    private $wanCache;
    private $csProvider;
    private $statsdDataFactory;
    private array $virtualDomains = [];
 
    public function __construct(
        ServiceOptions $options,
        ConfiguredReadOnlyMode $readOnlyMode,
        ChronologyProtector $chronologyProtector,
        BagOStuff $srvCache,
        WANObjectCache $wanCache,
        CriticalSectionProvider $csProvider,
        StatsdDataFactoryInterface $statsdDataFactory,
        array $virtualDomains
    ) {
        $this->options = $options;
        $this->readOnlyMode = $readOnlyMode;
        $this->chronologyProtector = $chronologyProtector;
        $this->srvCache = $srvCache;
        $this->wanCache = $wanCache;
        $this->csProvider = $csProvider;
        $this->statsdDataFactory = $statsdDataFactory;
        $this->virtualDomains = $virtualDomains;
    }
 
    public function applyDefaultConfig( array $lbConf ) {
        $this->options->assertRequiredOptions( self::APPLY_DEFAULT_CONFIG_OPTIONS );
 
        $typesWithSchema = self::getDbTypesWithSchemas();
        if ( Profiler::instance() instanceof ProfilerStub ) {
            $profilerCallback = null;
        } else {
            $profilerCallback = static function ( $section ) {
                return Profiler::instance()->scopedProfileIn( $section );
            };
        }
 
        $lbConf += [
            'localDomain' => new DatabaseDomain(
                $this->options->get( MainConfigNames::DBname ),
                $this->options->get( MainConfigNames::DBmwschema ),
                $this->options->get( MainConfigNames::DBprefix )
            ),
            'profiler' => $profilerCallback,
            'trxProfiler' => Profiler::instance()->getTransactionProfiler(),
            'logger' => LoggerFactory::getInstance( 'rdbms' ),
            'errorLogger' => [ MWExceptionHandler::class, 'logException' ],
            'deprecationLogger' => [ static::class, 'logDeprecation' ],
            'statsdDataFactory' => $this->statsdDataFactory,
            'cliMode' => $this->options->get( 'CommandLineMode' ),
            'readOnlyReason' => $this->readOnlyMode->getReason(),
            'defaultGroup' => $this->options->get( MainConfigNames::DBDefaultGroup ),
            'criticalSectionProvider' => $this->csProvider
        ];
 
        $serversCheck = [];
        // When making changes here, remember to also specify MediaWiki-specific options
        // for Database classes in the relevant Installer subclass.
        // Such as MysqlInstaller::openConnection and PostgresInstaller::openConnectionWithParams.
        if ( $lbConf['class'] === Wikimedia\Rdbms\LBFactorySimple::class ) {
            if ( isset( $lbConf['servers'] ) ) {
                // Server array is already explicitly configured
            } elseif ( is_array( $this->options->get( MainConfigNames::DBservers ) ) ) {
                $lbConf['servers'] = [];
                foreach ( $this->options->get( MainConfigNames::DBservers ) as $i => $server ) {
                    $lbConf['servers'][$i] = self::initServerInfo( $server, $this->options );
                }
            } else {
                $server = self::initServerInfo(
                    [
                        'host' => $this->options->get( MainConfigNames::DBserver ),
                        'user' => $this->options->get( MainConfigNames::DBuser ),
                        'password' => $this->options->get( MainConfigNames::DBpassword ),
                        'dbname' => $this->options->get( MainConfigNames::DBname ),
                        'type' => $this->options->get( MainConfigNames::DBtype ),
                        'load' => 1
                    ],
                    $this->options
                );
 
                if ( $this->options->get( MainConfigNames::DBssl ) ) {
                    $server['ssl'] = true;
                }
                $server['flags'] |= $this->options->get( MainConfigNames::DBcompress ) ? DBO_COMPRESS : 0;
 
                $lbConf['servers'] = [ $server ];
            }
            if ( !isset( $lbConf['externalClusters'] ) ) {
                $lbConf['externalClusters'] = $this->options->get( MainConfigNames::ExternalServers );
            }
 
            $serversCheck = $lbConf['servers'];
        } elseif ( $lbConf['class'] === Wikimedia\Rdbms\LBFactoryMulti::class ) {
            if ( isset( $lbConf['serverTemplate'] ) ) {
                if ( in_array( $lbConf['serverTemplate']['type'], $typesWithSchema, true ) ) {
                    $lbConf['serverTemplate']['schema'] = $this->options->get( MainConfigNames::DBmwschema );
                }
                $lbConf['serverTemplate']['sqlMode'] = $this->options->get( MainConfigNames::SQLMode );
                $serversCheck = [ $lbConf['serverTemplate'] ];
            }
        }
 
        self::assertValidServerConfigs(
            $serversCheck,
            $this->options->get( MainConfigNames::DBname ),
            $this->options->get( MainConfigNames::DBprefix )
        );
 
        $lbConf['chronologyProtector'] = $this->chronologyProtector;
        $lbConf['srvCache'] = $this->srvCache;
        $lbConf['wanCache'] = $this->wanCache;
        $lbConf['virtualDomains'] = $this->virtualDomains;
        $lbConf['virtualDomainsMapping'] = $this->options->get( MainConfigNames::VirtualDomainsMapping );
 
        return $lbConf;
    }
 
    private function getDbTypesWithSchemas() {
        return [ 'postgres' ];
    }
 
    private function initServerInfo( array $server, ServiceOptions $options ) {
        if ( $server['type'] === 'sqlite' ) {
            $httpMethod = $_SERVER['REQUEST_METHOD'] ?? null;
            // T93097: hint for how file-based databases (e.g. sqlite) should go about locking.
            // See https://www.sqlite.org/lang_transaction.html
            // See https://www.sqlite.org/lockingv3.html#shared_lock
            $isHttpRead = in_array( $httpMethod, [ 'GET', 'HEAD', 'OPTIONS', 'TRACE' ] );
            if ( MW_ENTRY_POINT === 'rest' && !$isHttpRead ) {
                // Hack to support some re-entrant invocations using sqlite
                // See: T259685, T91820
                $request = \MediaWiki\Rest\EntryPoint::getMainRequest();
                if ( $request->hasHeader( 'Promise-Non-Write-API-Action' ) ) {
                    $isHttpRead = true;
                }
            }
            $server += [
                'dbDirectory' => $options->get( MainConfigNames::SQLiteDataDir ),
                'trxMode' => $isHttpRead ? 'DEFERRED' : 'IMMEDIATE'
            ];
        } elseif ( $server['type'] === 'postgres' ) {
            $server += [ 'port' => $options->get( MainConfigNames::DBport ) ];
        }
 
        if ( in_array( $server['type'], self::getDbTypesWithSchemas(), true ) ) {
            $server += [ 'schema' => $options->get( MainConfigNames::DBmwschema ) ];
        }
 
        $flags = $server['flags'] ?? DBO_DEFAULT;
        if ( $options->get( MainConfigNames::DebugDumpSql )
            || $options->get( MainConfigNames::DebugLogFile )
            || $options->get( MainConfigNames::DebugToolbar )
        ) {
            $flags |= DBO_DEBUG;
        }
        $server['flags'] = $flags;
 
        $server += [
            'tablePrefix' => $options->get( MainConfigNames::DBprefix ),
            'sqlMode' => $options->get( MainConfigNames::SQLMode ),
        ];
 
        return $server;
    }
 
    private function assertValidServerConfigs( array $servers, $ldDB, $ldTP ) {
        foreach ( $servers as $server ) {
            $type = $server['type'] ?? null;
            $srvDB = $server['dbname'] ?? null; // server DB
            $srvTP = $server['tablePrefix'] ?? ''; // server table prefix
 
            if ( $type === 'mysql' ) {
                // A DB name is not needed to connect to mysql; 'dbname' is useless.
                // This field only defines the DB to use for unspecified DB domains.
                if ( $srvDB !== null && $srvDB !== $ldDB ) {
                    self::reportMismatchedDBs( $srvDB, $ldDB );
                }
            } elseif ( $type === 'postgres' ) {
                if ( $srvTP !== '' ) {
                    self::reportIfPrefixSet( $srvTP, $type );
                }
            }
 
            if ( $srvTP !== '' && $srvTP !== $ldTP ) {
                self::reportMismatchedPrefixes( $srvTP, $ldTP );
            }
        }
    }
 
    private function reportIfPrefixSet( $prefix, $dbType ) {
        $e = new UnexpectedValueException(
            "\$wgDBprefix is set to '$prefix' but the database type is '$dbType'. " .
            "MediaWiki does not support using a table prefix with this RDBMS type."
        );
        MWExceptionRenderer::output( $e, MWExceptionRenderer::AS_PRETTY );
        exit;
    }
 
    private function reportMismatchedDBs( $srvDB, $ldDB ) {
        $e = new UnexpectedValueException(
            "\$wgDBservers has dbname='$srvDB' but \$wgDBname='$ldDB'. " .
            "Set \$wgDBname to the database used by this wiki project. " .
            "There is rarely a need to set 'dbname' in \$wgDBservers. " .
            "Cross-wiki database access, use of WikiMap::getCurrentWikiDbDomain(), " .
            "use of Database::getDomainId(), and other features are not reliable when " .
            "\$wgDBservers does not match the local wiki database/prefix."
        );
        MWExceptionRenderer::output( $e, MWExceptionRenderer::AS_PRETTY );
        exit;
    }
 
    private function reportMismatchedPrefixes( $srvTP, $ldTP ) {
        $e = new UnexpectedValueException(
            "\$wgDBservers has tablePrefix='$srvTP' but \$wgDBprefix='$ldTP'. " .
            "Set \$wgDBprefix to the table prefix used by this wiki project. " .
            "There is rarely a need to set 'tablePrefix' in \$wgDBservers. " .
            "Cross-wiki database access, use of WikiMap::getCurrentWikiDbDomain(), " .
            "use of Database::getDomainId(), and other features are not reliable when " .
            "\$wgDBservers does not match the local wiki database/prefix."
        );
        MWExceptionRenderer::output( $e, MWExceptionRenderer::AS_PRETTY );
        exit;
    }
 
    public function getLBFactoryClass( array $config ) {
        $compat = [
            // For LocalSettings.php compat after removing underscores (since 1.23).
            'LBFactory_Single' => Wikimedia\Rdbms\LBFactorySingle::class,
            'LBFactory_Simple' => Wikimedia\Rdbms\LBFactorySimple::class,
            'LBFactory_Multi' => Wikimedia\Rdbms\LBFactoryMulti::class,
            // For LocalSettings.php compat after moving classes to namespaces (since 1.29).
            'LBFactorySingle' => Wikimedia\Rdbms\LBFactorySingle::class,
            'LBFactorySimple' => Wikimedia\Rdbms\LBFactorySimple::class,
            'LBFactoryMulti' => Wikimedia\Rdbms\LBFactoryMulti::class
        ];
 
        $class = $config['class'];
        return $compat[$class] ?? $class;
    }
 
    public function setDomainAliases( ILBFactory $lbFactory ) {
        $domain = DatabaseDomain::newFromId( $lbFactory->getLocalDomainID() );
        // For compatibility with hyphenated $wgDBname values on older wikis, handle callers
        // that assume corresponding database domain IDs and wiki IDs have identical values
        $rawLocalDomain = strlen( $domain->getTablePrefix() )
            ? "{$domain->getDatabase()}-{$domain->getTablePrefix()}"
            : (string)$domain->getDatabase();
 
        $lbFactory->setDomainAliases( [ $rawLocalDomain => $domain ] );
    }
 
    public function applyGlobalState(
        ILBFactory $lbFactory,
        Config $config,
        IBufferingStatsdDataFactory $stats
    ): void {
        if ( $config->get( 'CommandLineMode' ) ) {
            $lbFactory->getMainLB()->setTransactionListener(
                __METHOD__,
                static function ( $trigger ) use ( $stats, $config ) {
                    // During maintenance scripts and PHPUnit integration tests, we let
                    // DeferredUpdates run immediately from addUpdate(), unless a transaction
                    // is active. Notify DeferredUpdates after any commit to try now.
                    // See DeferredUpdates::tryOpportunisticExecute for why.
                    if ( $trigger === IDatabase::TRIGGER_COMMIT ) {
                        DeferredUpdates::tryOpportunisticExecute();
                    }
                    // Flush stats periodically in long-running CLI scripts to avoid OOM (T181385)
                    MediaWiki::emitBufferedStatsdData( $stats, $config );
                }
            );
            $lbFactory->setWaitForReplicationListener(
                __METHOD__,
                static function () use ( $stats, $config ) {
                    // Flush stats periodically in long-running CLI scripts to avoid OOM (T181385)
                    MediaWiki::emitBufferedStatsdData( $stats, $config );
                }
            );
 
        }
    }
 
    public static function logDeprecation( $msg ) {
        if ( isset( self::$loggedDeprecations[$msg] ) ) {
            return;
        }
        self::$loggedDeprecations[$msg] = true;
        MWDebug::sendRawDeprecated( $msg, true, wfGetCaller() );
    }
}