MediaWiki 1.30.2

[autoinstallsdev/mediawiki.git] / includes / db / CloneDatabase.php

diff --git a/includes/db/CloneDatabase.php b/includes/db/CloneDatabase.php
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+<?php
+/**
+ * Helper class for making a copy of the database, mostly for unit testing.
+ *
+ * Copyright © 2010 Chad Horohoe <chad@anyonecanedit.org>
+ * https://www.mediawiki.org/
+ *
+ * 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\MediaWikiServices;
+use Wikimedia\Rdbms\IMaintainableDatabase;
+
+class CloneDatabase {
+       /** @var string Table prefix for cloning */
+       private $newTablePrefix = '';
+
+       /** @var string Current table prefix */
+       private $oldTablePrefix = '';
+
+       /** @var array List of tables to be cloned */
+       private $tablesToClone = [];
+
+       /** @var bool Should we DROP tables containing the new names? */
+       private $dropCurrentTables = true;
+
+       /** @var bool Whether to use temporary tables or not */
+       private $useTemporaryTables = true;
+
+       /** @var IMaintainableDatabase */
+       private $db;
+
+       /**
+        * @param IMaintainableDatabase $db A database subclass
+        * @param array $tablesToClone An array of tables to clone, unprefixed
+        * @param string $newTablePrefix Prefix to assign to the tables
+        * @param string $oldTablePrefix Prefix on current tables, if not $wgDBprefix
+        * @param bool $dropCurrentTables
+        */
+       public function __construct( IMaintainableDatabase $db, array $tablesToClone,
+               $newTablePrefix, $oldTablePrefix = '', $dropCurrentTables = true
+       ) {
+               $this->db = $db;
+               $this->tablesToClone = $tablesToClone;
+               $this->newTablePrefix = $newTablePrefix;
+               $this->oldTablePrefix = $oldTablePrefix ? $oldTablePrefix : $this->db->tablePrefix();
+               $this->dropCurrentTables = $dropCurrentTables;
+       }
+
+       /**
+        * Set whether to use temporary tables or not
+        * @param bool $u Use temporary tables when cloning the structure
+        */
+       public function useTemporaryTables( $u = true ) {
+               $this->useTemporaryTables = $u;
+       }
+
+       /**
+        * Clone the table structure
+        */
+       public function cloneTableStructure() {
+               global $wgSharedTables, $wgSharedDB;
+               foreach ( $this->tablesToClone as $tbl ) {
+                       if ( $wgSharedDB && in_array( $tbl, $wgSharedTables, true ) ) {
+                               // Shared tables don't work properly when cloning due to
+                               // how prefixes are handled (T67654)
+                               throw new RuntimeException( "Cannot clone shared table $tbl." );
+                       }
+                       # Clean up from previous aborted run.  So that table escaping
+                       # works correctly across DB engines, we need to change the pre-
+                       # fix back and forth so tableName() works right.
+
+                       self::changePrefix( $this->oldTablePrefix );
+                       $oldTableName = $this->db->tableName( $tbl, 'raw' );
+
+                       self::changePrefix( $this->newTablePrefix );
+                       $newTableName = $this->db->tableName( $tbl, 'raw' );
+
+                       // Postgres: Temp tables are automatically deleted upon end of session
+                       //           Same Temp table name hides existing table for current session
+                       if ( $this->dropCurrentTables
+                               && !in_array( $this->db->getType(), [ 'oracle' ] )
+                       ) {
+                               if ( $oldTableName === $newTableName ) {
+                                       // Last ditch check to avoid data loss
+                                       throw new LogicException( "Not dropping new table, as '$newTableName'"
+                                               . " is name of both the old and the new table." );
+                               }
+                               $this->db->dropTable( $tbl, __METHOD__ );
+                               wfDebug( __METHOD__ . " dropping {$newTableName}\n" );
+                               // Dropping the oldTable because the prefix was changed
+                       }
+
+                       # Create new table
+                       wfDebug( __METHOD__ . " duplicating $oldTableName to $newTableName\n" );
+                       $this->db->duplicateTableStructure(
+                               $oldTableName, $newTableName, $this->useTemporaryTables );
+               }
+       }
+
+       /**
+        * Change the prefix back to the original.
+        * @param bool $dropTables Optionally drop the tables we created
+        */
+       public function destroy( $dropTables = false ) {
+               if ( $dropTables ) {
+                       self::changePrefix( $this->newTablePrefix );
+                       foreach ( $this->tablesToClone as $tbl ) {
+                               $this->db->dropTable( $tbl );
+                       }
+               }
+               self::changePrefix( $this->oldTablePrefix );
+       }
+
+       /**
+        * Change the table prefix on all open DB connections/
+        *
+        * @param string $prefix
+        * @return void
+        */
+       public static function changePrefix( $prefix ) {
+               global $wgDBprefix;
+
+               $lbFactory = MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
+               $lbFactory->setDomainPrefix( $prefix );
+               $wgDBprefix = $prefix;
+       }
+}