1 files changed, 140 insertions, 0 deletions
diff --git a/www/wiki/includes/db/CloneDatabase.php b/www/wiki/includes/db/CloneDatabase.php
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+++ b/www/wiki/includes/db/CloneDatabase.php
@@ -0,0 +1,140 @@
+<?php
+/**
+ * Helper class for making a copy of the database, mostly for unit testing.
+ *
+ * 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 = null, $dropCurrentTables = true
+	) {
+		$this->db = $db;
+		$this->tablesToClone = $tablesToClone;
+		$this->newTablePrefix = $newTablePrefix;
+		$this->oldTablePrefix = $oldTablePrefix !== null ? $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;
+	}
+}