rdbms: Avoid selectDB() call in LoadMonitor new connections

[mediawiki.git] / includes / installer / DatabaseInstaller.php

<?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 Deployment
 */
use Wikimedia\Rdbms\LBFactorySingle;
use Wikimedia\Rdbms\Database;
use Wikimedia\Rdbms\IDatabase;

/**
 * Base class for DBMS-specific installation helper classes.
 *
 * @ingroup Deployment
 * @since 1.17
 */
abstract class DatabaseInstaller {

        /**
         * The Installer object.
         *
         * @todo Naming this parent is confusing, 'installer' would be clearer.
         *
         * @var WebInstaller
         */
        public $parent;

        /**
         * The database connection.
         *
         * @var Database
         */
        public $db = null;

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

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

        /**
         * 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();
        }

        /**
         * Get HTML for a web form that configures this database. Configuration
         * at this time should be the minimum needed to connect and test
         * whether install or upgrade is required.
         *
         * If this is called, $this->parent can be assumed to be a WebInstaller.
         */
        abstract public function getConnectForm();

        /**
         * Set variables based on the request array, assuming it was submitted
         * via the form returned by getConnectForm(). Validate the connection
         * settings by attempting to connect with them.
         *
         * If this is called, $this->parent can be assumed to be a WebInstaller.
         *
         * @return Status
         */
        abstract public function submitConnectForm();

        /**
         * Get HTML for a web form that retrieves settings used for installation.
         * $this->parent can be assumed to be a WebInstaller.
         * If the DB type has no settings beyond those already configured with
         * getConnectForm(), this should return false.
         * @return bool
         */
        public function getSettingsForm() {
                return false;
        }

        /**
         * Set variables based on the request array, assuming it was submitted via
         * the form return by getSettingsForm().
         *
         * @return Status
         */
        public function submitSettingsForm() {
                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.
         *
         * @return Status
         */
        abstract public function openConnection();

        /**
         * 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.
         *
         * @return Status
         */
        public function getConnection() {
                if ( $this->db ) {
                        return Status::newGood( $this->db );
                }

                $status = $this->openConnection();
                if ( $status->isOK() ) {
                        $this->db = $status->value;
                        // Enable autocommit
                        $this->db->clearFlag( DBO_TRX );
                        $this->db->commit( __METHOD__ );
                }

                return $status;
        }

        /**
         * Apply a SQL source file to the database as part of running an installation step.
         *
         * @param string $sourceFileMethod
         * @param string $stepName
         * @param bool $archiveTableMustNotExist
         * @return Status
         */
        private function stepApplySourceFile(
                $sourceFileMethod,
                $stepName,
                $archiveTableMustNotExist = false
        ) {
                $status = $this->getConnection();
                if ( !$status->isOK() ) {
                        return $status;
                }
                $this->db->selectDB( $this->getVar( 'wgDBname' ) );

                if ( $archiveTableMustNotExist && $this->db->tableExists( 'archive', __METHOD__ ) ) {
                        $status->warning( "config-$stepName-tables-exist" );
                        $this->enableLB();

                        return $status;
                }

                $this->db->setFlag( DBO_DDLMODE ); // For Oracle's handling of schema files
                $this->db->begin( __METHOD__ );

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

                return $status;
        }

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

        /**
         * Insert update keys into table to prevent running unneded updates.
         *
         * @return Status
         */
        public function insertUpdateKeys() {
                return $this->stepApplySourceFile( 'getUpdateKeysPath', 'updates', false );
        }

        /**
         * 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 update key file,
         * otherwise default to update-keys.sql
         *
         * @param IDatabase $db
         * @return string
         */
        public function getUpdateKeysPath( $db ) {
                return $this->getSqlFilePath( $db, 'update-keys.sql' );
        }

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

                // Now run updates to create tables for old extensions
                DatabaseUpdater::newForDB( $this->db )->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 appropriate schema variables in the current database connection.
         *
         * This should be called after any request data has been imported, but before
         * any write operations to the database.
         */
        public function setupSchemaVars() {
                $status = $this->getConnection();
                if ( $status->isOK() ) {
                        $status->value->setSchemaVars( $this->getSchemaVars() );
                } else {
                        $msg = __METHOD__ . ': unexpected error while establishing'
                                . ' a database connection with message: '
                                . $status->getMessage()->plain();
                        throw new MWException( $msg );
                }
        }

        /**
         * Set up LBFactory so that wfGetDB() etc. works.
         * We set up a special LBFactory instance which returns the current
         * installer connection.
         */
        public function enableLB() {
                $status = $this->getConnection();
                if ( !$status->isOK() ) {
                        throw new MWException( __METHOD__ . ': unexpected DB connection error' );
                }

                \MediaWiki\MediaWikiServices::resetGlobalInstance();
                $services = \MediaWiki\MediaWikiServices::getInstance();

                $connection = $status->value;
                $services->redefineService( 'DBLoadBalancerFactory', function () use ( $connection ) {
                        return LBFactorySingle::newFromConnection( $connection );
                } );
        }

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

                $ret = true;
                ob_start( [ $this, 'outputHandler' ] );
                $up = DatabaseUpdater::newForDB( $this->db );
                try {
                        $up->doUpdates();
                } catch ( MWException $e ) {
                        echo "\nAn error occurred:\n";
                        echo $e->getText();
                        $ret = false;
                } catch ( Exception $e ) {
                        echo "\nAn error occurred:\n";
                        echo $e->getMessage();
                        $ret = false;
                }
                $up->purgeCache();
                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,
                // config-type-oracle
                return wfMessage( 'config-type-' . $this->getName() )->text();
        }

        /**
         * Get a name=>value map of MW configuration globals for the default values.
         * @return array
         */
        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 );
        }

        /**
         * Get a labelled text box to configure a local variable.
         *
         * @param string $var
         * @param string $label
         * @param array $attribs
         * @param string $helpData
         * @return string
         */
        public function getTextBox( $var, $label, $attribs = [], $helpData = "" ) {
                $name = $this->getName() . '_' . $var;
                $value = $this->getVar( $var );
                if ( !isset( $attribs ) ) {
                        $attribs = [];
                }

                return $this->parent->getTextBox( [
                        'var' => $var,
                        'label' => $label,
                        'attribs' => $attribs,
                        'controlName' => $name,
                        'value' => $value,
                        'help' => $helpData
                ] );
        }

        /**
         * Get a labelled password box to configure a local variable.
         * Implements password hiding.
         *
         * @param string $var
         * @param string $label
         * @param array $attribs
         * @param string $helpData
         * @return string
         */
        public function getPasswordBox( $var, $label, $attribs = [], $helpData = "" ) {
                $name = $this->getName() . '_' . $var;
                $value = $this->getVar( $var );
                if ( !isset( $attribs ) ) {
                        $attribs = [];
                }

                return $this->parent->getPasswordBox( [
                        'var' => $var,
                        'label' => $label,
                        'attribs' => $attribs,
                        'controlName' => $name,
                        'value' => $value,
                        'help' => $helpData
                ] );
        }

        /**
         * Get a labelled checkbox to configure a local boolean variable.
         *
         * @param string $var
         * @param string $label
         * @param array $attribs Optional.
         * @param string $helpData Optional.
         * @return string
         */
        public function getCheckBox( $var, $label, $attribs = [], $helpData = "" ) {
                $name = $this->getName() . '_' . $var;
                $value = $this->getVar( $var );

                return $this->parent->getCheckBox( [
                        'var' => $var,
                        'label' => $label,
                        'attribs' => $attribs,
                        'controlName' => $name,
                        'value' => $value,
                        'help' => $helpData
                ] );
        }

        /**
         * Get a set of labelled radio buttons.
         *
         * @param array $params Parameters are:
         *      var:            The variable to be configured (required)
         *      label:          The message name for the label (required)
         *      itemLabelPrefix: The message name prefix for the item labels (required)
         *      values:         List of allowed values (required)
         *      itemAttribs     Array of attribute arrays, outer key is the value name (optional)
         *
         * @return string
         */
        public function getRadioSet( $params ) {
                $params['controlName'] = $this->getName() . '_' . $params['var'];
                $params['value'] = $this->getVar( $params['var'] );

                return $this->parent->getRadioSet( $params );
        }

        /**
         * Convenience function to set variables based on form data.
         * Assumes that variables containing "password" in the name are (potentially
         * fake) passwords.
         * @param array $varNames
         * @return array
         */
        public function setVarsFromRequest( $varNames ) {
                return $this->parent->setVarsFromRequest( $varNames, $this->getName() . '_' );
        }

        /**
         * 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 = $this->getConnection();
                if ( !$status->isOK() ) {
                        return false;
                }

                if ( !$this->db->selectDB( $this->getVar( 'wgDBname' ) ) ) {
                        return false;
                }

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

        /**
         * Get a standard install-user fieldset.
         *
         * @return string
         */
        public function getInstallUserBox() {
                return Html::openElement( 'fieldset' ) .
                        Html::element( 'legend', [], wfMessage( 'config-db-install-account' )->text() ) .
                        $this->getTextBox(
                                '_InstallUser',
                                'config-db-username',
                                [ 'dir' => 'ltr' ],
                                $this->parent->getHelpBox( 'config-db-install-username' )
                        ) .
                        $this->getPasswordBox(
                                '_InstallPassword',
                                'config-db-password',
                                [ 'dir' => 'ltr' ],
                                $this->parent->getHelpBox( 'config-db-install-password' )
                        ) .
                        Html::closeElement( 'fieldset' );
        }

        /**
         * Submit a standard install user fieldset.
         * @return Status
         */
        public function submitInstallUserBox() {
                $this->setVarsFromRequest( [ '_InstallUser', '_InstallPassword' ] );

                return Status::newGood();
        }

        /**
         * Get a standard web-user fieldset
         * @param string|bool $noCreateMsg Message to display instead of the creation checkbox.
         *   Set this to false to show a creation checkbox (default).
         *
         * @return string
         */
        public function getWebUserBox( $noCreateMsg = false ) {
                $wrapperStyle = $this->getVar( '_SameAccount' ) ? 'display: none' : '';
                $s = Html::openElement( 'fieldset' ) .
                        Html::element( 'legend', [], wfMessage( 'config-db-web-account' )->text() ) .
                        $this->getCheckBox(
                                '_SameAccount', 'config-db-web-account-same',
                                [ 'class' => 'hideShowRadio', 'rel' => 'dbOtherAccount' ]
                        ) .
                        Html::openElement( 'div', [ 'id' => 'dbOtherAccount', 'style' => $wrapperStyle ] ) .
                        $this->getTextBox( 'wgDBuser', 'config-db-username' ) .
                        $this->getPasswordBox( 'wgDBpassword', 'config-db-password' ) .
                        $this->parent->getHelpBox( 'config-db-web-help' );
                if ( $noCreateMsg ) {
                        $s .= $this->parent->getWarningBox( wfMessage( $noCreateMsg )->plain() );
                } else {
                        $s .= $this->getCheckBox( '_CreateDBAccount', 'config-db-web-create' );
                }
                $s .= Html::closeElement( 'div' ) . Html::closeElement( 'fieldset' );

                return $s;
        }

        /**
         * Submit the form from getWebUserBox().
         *
         * @return Status
         */
        public function submitWebUserBox() {
                $this->setVarsFromRequest(
                        [ 'wgDBuser', 'wgDBpassword', '_SameAccount', '_CreateDBAccount' ]
                );

                if ( $this->getVar( '_SameAccount' ) ) {
                        $this->setVar( 'wgDBuser', $this->getVar( '_InstallUser' ) );
                        $this->setVar( 'wgDBpassword', $this->getVar( '_InstallPassword' ) );
                }

                if ( $this->getVar( '_CreateDBAccount' ) && strval( $this->getVar( 'wgDBpassword' ) ) == '' ) {
                        return Status::newFatal( 'config-db-password-empty', $this->getVar( 'wgDBuser' ) );
                }

                return Status::newGood();
        }

        /**
         * Common function for databases that don't understand the MySQLish syntax of interwiki.sql.
         *
         * @return Status
         */
        public function populateInterwikiTable() {
                $status = $this->getConnection();
                if ( !$status->isOK() ) {
                        return $status;
                }
                $this->db->selectDB( $this->getVar( 'wgDBname' ) );

                if ( $this->db->selectRow( 'interwiki', '*', [], __METHOD__ ) ) {
                        $status->warning( 'config-install-interwiki-exists' );

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

                return Status::newGood();
        }

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