wikimedia/mediawiki-core

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includes/installer/DatabaseInstaller.php

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<?php

/**
 * DBMS-specific installation helper.
 *
 * 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 Installer
 */

namespace MediaWiki\Installer;

use Exception;
use MediaWiki\Status\Status;
use MWLBFactory;
use RuntimeException;
use Wikimedia\AtEase\AtEase;
use Wikimedia\Rdbms\Database;
use Wikimedia\Rdbms\DatabaseDomain;
use Wikimedia\Rdbms\DBConnectionError;
use Wikimedia\Rdbms\DBExpectedError;
use Wikimedia\Rdbms\IDatabase;
use Wikimedia\Rdbms\LBFactorySingle;

/**
 * Base class for DBMS-specific installation helper classes.
 *
 * @ingroup Installer
 * @since 1.17
 */
abstract class DatabaseInstaller {
    /**
     * A connection for creating DBs, suitable for pre-installation.
     */
    public const CONN_CREATE_DATABASE = 'create-database';

    /**
     * A connection to the new DB, for creating schemas and other similar
     * objects in the new DB.
     */
    public const CONN_CREATE_SCHEMA = 'create-schema';

    /**
     * A connection with a role suitable for creating tables.
     */
    public const CONN_CREATE_TABLES = 'create-tables';

    /**
     * Legacy default connection type. Before MW 1.43, getConnection() with no
     * parameters would return the cached connection. The state (especially the
     * selected domain) would depend on the previously executed install steps.
     * Using this constant tries to reproduce this behaviour.
     *
     * @deprecated since 1.43
     */
    public const CONN_DONT_KNOW = 'dont-know';

    /**
     * The Installer object.
     *
     * @var Installer
     */
    public $parent;

    /**
     * @var string Set by subclasses
     */
    public static $minimumVersion;

    /**
     * @var string Set by subclasses
     */
    protected static $notMinimumVersionMessage;

    /**
     * @deprecated since 1.43 -- use definitelyGetConnection()
     * @var Database
     */
    public $db = null;

    /** @var Database|null */
    private $cachedConn;
    /** @var string|null */
    private $cachedConnType;

    /**
     * Internal variables for installation.
     *
     * @var array
     */
    protected $internalDefaults = [];

    /**
     * Array of MW configuration globals this class uses.
     *
     * @var array
     */
    protected $globalNames = [];

    /**
     * Whether the provided version meets the necessary requirements for this type
     *
     * @param IDatabase $conn
     * @return Status
     * @since 1.30
     */
    public static function meetsMinimumRequirement( IDatabase $conn ) {
        $serverVersion = $conn->getServerVersion();
        if ( version_compare( $serverVersion, static::$minimumVersion ) < 0 ) {
            return Status::newFatal(
                static::$notMinimumVersionMessage, static::$minimumVersion, $serverVersion
            );
        }

        return Status::newGood();
    }

    /**
     * Return the internal name, e.g. 'mysql', or 'sqlite'.
     */
    abstract public function getName();

    /**
     * @return bool Returns true if the client library is compiled in.
     */
    abstract public function isCompiled();

    /**
     * Checks for installation prerequisites other than those checked by isCompiled()
     * @since 1.19
     * @return Status
     */
    public function checkPrerequisites() {
        return Status::newGood();
    }

    /**
     * Open a connection to the database using the administrative user/password
     * currently defined in the session, without any caching. Returns a status
     * object. On success, the status object will contain a Database object in
     * its value member.
     *
     * @param string $type One of the self::CONN_* constants, except CONN_DONT_KNOW
     * @return ConnectionStatus
     */
    abstract protected function openConnection( string $type );

    /**
     * Create the database and return a Status object indicating success or
     * failure.
     *
     * @return Status
     */
    abstract public function setupDatabase();

    /**
     * Connect to the database using the administrative user/password currently
     * defined in the session. Returns a status object. On success, the status
     * object will contain a Database object in its value member.
     *
     * This will return a cached connection if one is available.
     *
     * @param string $type One of the self::CONN_* constants. Using CONN_DONT_KNOW
     *   is deprecated and will cause an exception to be thrown in a future release.
     * @return ConnectionStatus
     */
    public function getConnection( $type = self::CONN_DONT_KNOW ) {
        if ( $type === self::CONN_DONT_KNOW ) {
            if ( $this->cachedConnType ) {
                $type = $this->cachedConnType;
            } else {
                $type = self::CONN_CREATE_DATABASE;
            }
        }
        if ( $this->cachedConn ) {
            if ( $this->cachedConnType === $type ) {
                return new ConnectionStatus( $this->cachedConn );
            } else {
                return $this->changeConnType( $this->cachedConn, $this->cachedConnType, $type );
            }
        }
        $status = $this->openConnection( $type );
        if ( $status->isOK() ) {
            $this->cachedConn = $status->getDB();
            $this->cachedConnType = $type;
            // Assign to $this->db for b/c
            $this->db = $this->cachedConn;

            if ( $type === self::CONN_CREATE_SCHEMA || $type === self::CONN_CREATE_TABLES ) {
                $this->cachedConn->setSchemaVars( $this->getSchemaVars() );
            }
        }

        return $status;
    }

    /**
     * Get a connection and unwrap it from its Status object, throwing an
     * exception on failure.
     *
     * @param string $type
     * @return Database
     */
    public function definitelyGetConnection( string $type ): Database {
        $status = $this->getConnection( $type );
        if ( !$status->isOK() ) {
            throw new RuntimeException( __METHOD__ . ': unexpected DB connection error' );
        }
        return $status->getDB();
    }

    /**
     * Change the type of a connection.
     *
     * CONN_CREATE_DATABASE means the domain is indeterminate and irrelevant,
     * so converting from this type can be done by selecting the domain, and
     * converting to it is a no-op.
     *
     * CONN_CREATE_SCHEMA means the domain is correct but tables created by
     * PostgreSQL will have the incorrect role. So to convert from this to
     * CONN_CREATE_TABLES, we set the role.
     *
     * CONN_CREATE_TABLES means a fully-configured connection, suitable for
     * most tasks, so converting from it is a no-op.
     *
     * @param Database $conn
     * @param string &$storedType One of the self::CONN_* constants. An in/out
     *   parameter, set to the new type on success. It is set to the "real" new
     *   type, reflecting the highest configuration level reached, to avoid
     *   unnecessary selectDomain() calls when we need to temporarily give an
     *   unconfigured connection.
     * @param string $newType One of the self::CONN_* constants
     * @return ConnectionStatus
     */
    protected function changeConnType( Database $conn, &$storedType, $newType ) {
        // Change type from database to schema, if requested
        if ( $storedType === self::CONN_CREATE_DATABASE ) {
            if ( $newType === self::CONN_CREATE_SCHEMA || $newType === self::CONN_CREATE_TABLES ) {
                $conn->selectDomain( new DatabaseDomain(
                    $this->getVar( 'wgDBname' ),
                    $this->getVar( 'wgDBmwschema' ),
                    $this->getVar( 'wgDBprefix' ) ?? ''
                ) );
                $conn->setSchemaVars( $this->getSchemaVars() );
                $storedType = self::CONN_CREATE_SCHEMA;
            }
        }
        // Change type from schema to tables, if requested
        if ( $newType === self::CONN_CREATE_TABLES && $storedType === self::CONN_CREATE_SCHEMA ) {
            $status = $this->changeConnTypeFromSchemaToTables( $conn );
            if ( $status->isOK() ) {
                $storedType = self::CONN_CREATE_TABLES;
            }
            return $status;
        }
        return new ConnectionStatus( $conn );
    }

    /**
     * Change the type of a connection from CONN_CREATE_SCHEMA to CONN_CREATE_TABLES.
     * Postgres overrides this.
     *
     * @param Database $conn
     * @return ConnectionStatus
     */
    protected function changeConnTypeFromSchemaToTables( Database $conn ) {
        return new ConnectionStatus( $conn );
    }

    /**
     * Apply a SQL source file to the database as part of running an installation step.
     *
     * @param string $sourceFileMethod
     * @param string $stepName
     * @param string|false $tableThatMustNotExist
     * @return Status
     */
    private function stepApplySourceFile(
        $sourceFileMethod,
        $stepName,
        $tableThatMustNotExist = false
    ) {
        $status = $this->getConnection( self::CONN_CREATE_TABLES );
        if ( !$status->isOK() ) {
            return $status;
        }
        $conn = $status->getDB();

        if ( $tableThatMustNotExist && $conn->tableExists( $tableThatMustNotExist, __METHOD__ ) ) {
            $status->warning( "config-$stepName-tables-exist" );
            $this->enableLB();

            return $status;
        }

        $conn->setFlag( DBO_DDLMODE );
        $conn->begin( __METHOD__ );

        $error = $conn->sourceFile(
            call_user_func( [ $this, $sourceFileMethod ], $conn )
        );
        if ( $error !== true ) {
            $conn->reportQueryError( $error, 0, '', __METHOD__ );
            $conn->rollback( __METHOD__ );
            $status->fatal( "config-$stepName-tables-failed", $error );
        } else {
            $conn->commit( __METHOD__ );
        }
        // Resume normal operations
        if ( $status->isOK() ) {
            $this->enableLB();
        }

        return $status;
    }

    /**
     * Create database tables from scratch from the automatically generated file
     *
     * @return Status
     */
    public function createTables() {
        return $this->stepApplySourceFile( 'getGeneratedSchemaPath', 'install', 'archive' );
    }

    /**
     * Create database tables from scratch.
     *
     * @return Status
     */
    public function createManualTables() {
        return $this->stepApplySourceFile( 'getSchemaPath', 'install-manual' );
    }

    /**
     * Insert update keys into table to prevent running unneeded updates.
     *
     * @return Status
     */
    public function insertUpdateKeys() {
        $updater = DatabaseUpdater::newForDB(
            $this->definitelyGetConnection( self::CONN_CREATE_TABLES ) );
        $updater->insertInitialUpdateKeys();
        return Status::newGood();
    }

    /**
     * Return a path to the DBMS-specific SQL file if it exists,
     * otherwise default SQL file
     *
     * @param IDatabase $db
     * @param string $filename
     * @return string
     */
    private function getSqlFilePath( $db, $filename ) {
        global $IP;

        $dbmsSpecificFilePath = "$IP/maintenance/" . $db->getType() . "/$filename";
        if ( file_exists( $dbmsSpecificFilePath ) ) {
            return $dbmsSpecificFilePath;
        } else {
            return "$IP/maintenance/$filename";
        }
    }

    /**
     * Return a path to the DBMS-specific schema file,
     * otherwise default to tables.sql
     *
     * @param IDatabase $db
     * @return string
     */
    public function getSchemaPath( $db ) {
        return $this->getSqlFilePath( $db, 'tables.sql' );
    }

    /**
     * Return a path to the DBMS-specific automatically generated schema file.
     *
     * @param IDatabase $db
     * @return string
     */
    public function getGeneratedSchemaPath( $db ) {
        return $this->getSqlFilePath( $db, 'tables-generated.sql' );
    }

    /**
     * Create the tables for each extension the user enabled
     * @return Status
     */
    public function createExtensionTables() {
        $status = $this->getConnection( self::CONN_CREATE_TABLES );
        if ( !$status->isOK() ) {
            return $status;
        }
        $this->enableLB();

        // Now run updates to create tables for old extensions
        $updater = DatabaseUpdater::newForDB( $status->getDB() );
        $updater->setAutoExtensionHookContainer( $this->parent->getAutoExtensionHookContainer() );
        $updater->doUpdates( [ 'extensions' ] );

        return $status;
    }

    /**
     * Get the DBMS-specific options for LocalSettings.php generation.
     *
     * @return string
     */
    abstract public function getLocalSettings();

    /**
     * Override this to provide DBMS-specific schema variables, to be
     * substituted into tables.sql and other schema files.
     * @return array
     */
    public function getSchemaVars() {
        return [];
    }

    /**
     * Set up LBFactory so that getPrimaryDatabase() etc. works.
     * We set up a special LBFactory instance which returns the current
     * installer connection.
     */
    public function enableLB() {
        $connection = $this->definitelyGetConnection( self::CONN_CREATE_TABLES );
        $virtualDomains = array_merge(
            $this->parent->getVirtualDomains(),
            MWLBFactory::CORE_VIRTUAL_DOMAINS
        );

        $this->parent->resetMediaWikiServices( null, [
            'DBLoadBalancerFactory' => static function () use ( $virtualDomains, $connection ) {
                return LBFactorySingle::newFromConnection(
                    $connection,
                    [ 'virtualDomains' => $virtualDomains ]
                );
            }
        ] );
    }

    /**
     * Perform database upgrades
     *
     * @return bool
     */
    public function doUpgrade() {
        $this->enableLB();

        $ret = true;
        ob_start( [ $this, 'outputHandler' ] );
        $up = DatabaseUpdater::newForDB(
            $this->definitelyGetConnection( self::CONN_CREATE_TABLES ) );
        try {
            $up->doUpdates();
            $up->purgeCache();
        } catch ( Exception $e ) {
            // TODO: Should this use MWExceptionRenderer?
            echo "\nAn error occurred:\n";
            echo $e->getMessage();
            $ret = false;
        }
        ob_end_flush();

        return $ret;
    }

    /**
     * Allow DB installers a chance to make last-minute changes before installation
     * occurs. This happens before setupDatabase() or createTables() is called, but
     * long after the constructor. Helpful for things like modifying setup steps :)
     */
    public function preInstall() {
    }

    /**
     * Allow DB installers a chance to make checks before upgrade.
     */
    public function preUpgrade() {
    }

    /**
     * Get an array of MW configuration globals that will be configured by this class.
     * @return array
     */
    public function getGlobalNames() {
        return $this->globalNames;
    }

    /**
     * Construct and initialise parent.
     * This is typically only called from Installer::getDBInstaller()
     * @param WebInstaller $parent
     */
    public function __construct( $parent ) {
        $this->parent = $parent;
    }

    /**
     * Convenience function.
     * Check if a named extension is present.
     *
     * @param string $name
     * @return bool
     */
    protected static function checkExtension( $name ) {
        return extension_loaded( $name );
    }

    /**
     * Get the internationalised name for this DBMS.
     * @return string
     */
    public function getReadableName() {
        // Messages: config-type-mysql, config-type-postgres, config-type-sqlite
        return wfMessage( 'config-type-' . $this->getName() )->text();
    }

    /**
     * Get a name=>value map of MW configuration globals for the default values.
     * @return array
     * @return-taint none
     */
    public function getGlobalDefaults() {
        $defaults = [];
        foreach ( $this->getGlobalNames() as $var ) {
            if ( isset( $GLOBALS[$var] ) ) {
                $defaults[$var] = $GLOBALS[$var];
            }
        }
        return $defaults;
    }

    /**
     * Get a name=>value map of internal variables used during installation.
     * @return array
     */
    public function getInternalDefaults() {
        return $this->internalDefaults;
    }

    /**
     * Get a variable, taking local defaults into account.
     * @param string $var
     * @param mixed|null $default
     * @return mixed
     */
    public function getVar( $var, $default = null ) {
        $defaults = $this->getGlobalDefaults();
        $internal = $this->getInternalDefaults();
        if ( isset( $defaults[$var] ) ) {
            $default = $defaults[$var];
        } elseif ( isset( $internal[$var] ) ) {
            $default = $internal[$var];
        }

        return $this->parent->getVar( $var, $default );
    }

    /**
     * Convenience alias for $this->parent->setVar()
     * @param string $name
     * @param mixed $value
     */
    public function setVar( $name, $value ) {
        $this->parent->setVar( $name, $value );
    }

    abstract public function getConnectForm( WebInstaller $webInstaller ): DatabaseConnectForm;

    abstract public function getSettingsForm( WebInstaller $webInstaller ): DatabaseSettingsForm;

    /**
     * Determine whether an existing installation of MediaWiki is present in
     * the configured administrative connection. Returns true if there is
     * such a wiki, false if the database doesn't exist.
     *
     * Traditionally, this is done by testing for the existence of either
     * the revision table or the cur table.
     *
     * @return bool
     */
    public function needsUpgrade() {
        $status = $this->getConnection( self::CONN_CREATE_DATABASE );
        if ( !$status->isOK() ) {
            return false;
        }
        $db = $status->getDB();

        try {
            $this->selectDatabase( $db, $this->getVar( 'wgDBname' ) );
        } catch ( DBConnectionError $e ) {
            // Don't catch DBConnectionError
            throw $e;
        } catch ( DBExpectedError $e ) {
            return false;
        }

        return $db->tableExists( 'cur', __METHOD__ ) ||
            $db->tableExists( 'revision', __METHOD__ );
    }

    /**
     * Common function for databases that don't understand the MySQLish syntax of interwiki.list.
     *
     * @return Status
     */
    public function populateInterwikiTable() {
        $status = $this->getConnection( self::CONN_CREATE_TABLES );
        if ( !$status->isOK() ) {
            return $status;
        }
        $conn = $status->getDB();

        $row = $conn->newSelectQueryBuilder()
            ->select( '1' )
            ->from( 'interwiki' )
            ->caller( __METHOD__ )->fetchRow();
        if ( $row ) {
            $status->warning( 'config-install-interwiki-exists' );

            return $status;
        }
        global $IP;
        AtEase::suppressWarnings();
        $rows = file( "$IP/maintenance/interwiki.list",
            FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES );
        AtEase::restoreWarnings();
        if ( !$rows ) {
            return Status::newFatal( 'config-install-interwiki-list' );
        }
        $insert = $conn->newInsertQueryBuilder()
            ->insertInto( 'interwiki' );
        foreach ( $rows as $row ) {
            $row = preg_replace( '/^\s*([^#]*?)\s*(#.*)?$/', '\\1', $row ); // strip comments - whee
            if ( $row == "" ) {
                continue;
            }
            $row .= "|";
            $insert->row(
                array_combine(
                    [ 'iw_prefix', 'iw_url', 'iw_local', 'iw_api', 'iw_wikiid' ],
                    explode( '|', $row )
                )
            );
        }
        $insert->caller( __METHOD__ )->execute();

        return Status::newGood();
    }

    public function outputHandler( $string ) {
        return htmlspecialchars( $string );
    }

    /**
     * @param Database $conn
     * @param string $database
     * @return bool
     * @since 1.39
     */
    protected function selectDatabase( Database $conn, string $database ) {
        $schema = $conn->dbSchema();
        $prefix = $conn->tablePrefix();

        $conn->selectDomain( new DatabaseDomain(
            $database,
            // DatabaseDomain uses null for unspecified schemas
            ( $schema !== '' ) ? $schema : null,
            $prefix
        ) );

        return true;
    }
}