MWLBConfig.php

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<?php
namespace MediaWiki\DB;
 
use MediaWiki\Config\ServiceOptions;
use MediaWiki\Exception\MWExceptionRenderer;
use MediaWiki\MainConfigNames;
use MediaWiki\Rest\EntryPoint;
use UnexpectedValueException;
use Wikimedia\Rdbms\DatabaseDomain;
use Wikimedia\Rdbms\LBFactoryMulti;
use Wikimedia\Rdbms\LBFactorySimple;
 
class MWLBConfig {
    private const array DB_TYPES_WITH_SCHEMAS = [ 'postgres' ];
 
    public const APPLY_DEFAULT_CONFIG_OPTIONS = [
        MainConfigNames::DBcompress,
        MainConfigNames::DBmwschema,
        MainConfigNames::DBname,
        MainConfigNames::DBpassword,
        MainConfigNames::DBport,
        MainConfigNames::DBprefix,
        MainConfigNames::DBserver,
        MainConfigNames::DBservers,
        MainConfigNames::DBssl,
        MainConfigNames::DBStrictWarnings,
        MainConfigNames::DBtype,
        MainConfigNames::DBuser,
        MainConfigNames::DebugDumpSql,
        MainConfigNames::DebugLogFile,
        MainConfigNames::DebugToolbar,
        MainConfigNames::ExternalServers,
        MainConfigNames::SQLiteDataDir,
        MainConfigNames::SQLMode,
        MainConfigNames::VirtualDomainsMapping,
        MainConfigNames::RemoteVirtualDomainsMapping,
    ];
    private ServiceOptions $options;
 
    private array $lbConf;
 
    public function __construct(
        ServiceOptions $options,
        array $lbConf
    ) {
        $this->options = $options;
        $this->lbConf = $this->applyConfig( $lbConf );
    }
 
    private function applyConfig( array $lbConf ): array {
        $this->options->assertRequiredOptions( self::APPLY_DEFAULT_CONFIG_OPTIONS );
 
        $lbConf += [
            'localDomain' => new DatabaseDomain(
                $this->options->get( MainConfigNames::DBname ),
                $this->options->get( MainConfigNames::DBmwschema ),
                $this->options->get( MainConfigNames::DBprefix )
            ),
        ];
 
        $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'] === 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] = $this->initServerInfo( $server, $this->options );
                }
            } else {
                $server = $this->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;
                if ( $this->options->get( MainConfigNames::DBStrictWarnings ) ) {
                    $server['strictWarnings'] = true;
                }
 
                $lbConf['servers'] = [ $server ];
            }
            if ( !isset( $lbConf['externalClusters'] ) ) {
                $lbConf['externalClusters'] = $this->options->get( MainConfigNames::ExternalServers );
            }
 
            $serversCheck = $lbConf['servers'];
        } elseif ( $lbConf['class'] === LBFactoryMulti::class ) {
            if ( isset( $lbConf['serverTemplate'] ) ) {
                if ( in_array( $lbConf['serverTemplate']['type'], self::DB_TYPES_WITH_SCHEMAS, true ) ) {
                    $lbConf['serverTemplate']['schema'] = $this->options->get( MainConfigNames::DBmwschema );
                }
                $lbConf['serverTemplate']['sqlMode'] = $this->options->get( MainConfigNames::SQLMode );
                $serversCheck = [ $lbConf['serverTemplate'] ];
            }
        }
 
        $this->assertValidServerConfigs(
            $serversCheck,
            $this->options->get( MainConfigNames::DBname ),
            $this->options->get( MainConfigNames::DBprefix )
        );
 
        $lbConf['virtualDomainsMapping'] = $this->options->get( MainConfigNames::VirtualDomainsMapping );
        $lbConf['remoteVirtualDomainsMapping'] = $this->options->get( MainConfigNames::RemoteVirtualDomainsMapping );
 
        return $lbConf;
    }
 
    public function getConfig() {
        return $this->lbConf;
    }
 
    private function initServerInfo( array $server, ServiceOptions $options ): array {
        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 = 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::DB_TYPES_WITH_SCHEMAS, 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, string $ldDB, string $ldTP ): void {
        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 ) {
                    $this->reportMismatchedDBs( $srvDB, $ldDB );
                }
            } elseif ( $type === 'postgres' ) {
                if ( $srvTP !== '' ) {
                    $this->reportIfPrefixSet( $srvTP, $type );
                }
            }
 
            if ( $srvTP !== '' && $srvTP !== $ldTP ) {
                $this->reportMismatchedPrefixes( $srvTP, $ldTP );
            }
        }
    }
 
    private function reportIfPrefixSet( string $prefix, string $dbType ): never {
        $e = new UnexpectedValueException(
            "\$wgDBprefix is set to '$prefix' but the database type is '$dbType'. " .
            "MediaWiki does not support using a table prefix with this RDBMS type."
        );
        MWExceptionRenderer::output( $e, MWExceptionRenderer::AS_RAW );
        exit;
    }
 
    private function reportMismatchedDBs( string $srvDB, string $ldDB ): never {
        $e = new UnexpectedValueException(
            "\$wgDBservers has dbname='$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_RAW );
        exit;
    }
 
    private function reportMismatchedPrefixes( string $srvTP, string $ldTP ): never {
        $e = new UnexpectedValueException(
            "\$wgDBservers has tablePrefix='$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_RAW );
        exit;
    }
}