2 files changed, 95 insertions, 1 deletions
diff --git a/includes/dao/DBAccessBase.php b/includes/dao/DBAccessBase.php
new file mode 100644
index 00000000..6c009dee
--- /dev/null
+++ b/includes/dao/DBAccessBase.php
@@ -0,0 +1,92 @@
+<?php
+
+/**
+ * Base class for objects that allow access to other wiki's databases using
+ * the foreign database access mechanism implemented by LBFactory_multi.
+ *
+ * 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
+ *
+ * @since 1.21
+ *
+ * @file
+ * @ingroup Database
+ *
+ * @licence GNU GPL v2+
+ * @author Daniel Kinzler
+ */
+abstract class DBAccessBase implements IDBAccessObject {
+
+	/**
+	 * @var String|bool $wiki The target wiki's name. This must be an ID
+	 * that LBFactory can understand.
+	 */
+	protected $wiki = false;
+
+	/**
+	 * @param string|bool $wiki The target wiki's name. This must be an ID
+	 * that LBFactory can understand.
+	 */
+	public function __construct( $wiki = false ) {
+		$this->wiki = $wiki;
+	}
+
+	/**
+	 * Returns a database connection.
+	 *
+	 * @see wfGetDB()
+	 * @see LoadBalancer::getConnection()
+	 *
+	 * @since 1.21
+	 *
+	 * @param int $id Which connection to use
+	 * @param array $groups Query groups
+	 *
+	 * @return DatabaseBase
+	 */
+	protected function getConnection( $id, $groups = array() ) {
+		$loadBalancer = wfGetLB( $this->wiki );
+		return $loadBalancer->getConnection( $id, $groups, $this->wiki );
+	}
+
+	/**
+	 * Releases a database connection and makes it available for recycling.
+	 *
+	 * @see LoadBalancer::reuseConnection()
+	 *
+	 * @since 1.21
+	 *
+	 * @param DatabaseBase  $db the database connection to release.
+	 */
+	protected function releaseConnection( DatabaseBase $db ) {
+		if ( $this->wiki !== false ) {
+			$loadBalancer = $this->getLoadBalancer();
+			$loadBalancer->reuseConnection( $db );
+		}
+	}
+
+	/**
+	 * Get the database type used for read operations.
+	 *
+	 * @see wfGetLB
+	 *
+	 * @since 1.21
+	 *
+	 * @return LoadBalancer The database load balancer object
+	 */
+	public function getLoadBalancer() {
+		return wfGetLB( $this->wiki );
+	}
+}
diff --git a/includes/dao/IDBAccessObject.php b/includes/dao/IDBAccessObject.php
index e30522a5..4eb6ff3e 100644
--- a/includes/dao/IDBAccessObject.php
+++ b/includes/dao/IDBAccessObject.php
@@ -41,10 +41,12 @@
  *   - b) Determine the new row (expensive, so we don't want to hold locks now)
  *   - c) Re-read the current row with READ_LOCKING; if it changed then bail out
  *   - d) otherwise, do the updates
+ *
+ * @since 1.20
  */
 interface IDBAccessObject {
 	// Constants for object loading bitfield flags (higher => higher QoS)
-	const READ_LATEST  = 1; // read from the master
+	const READ_LATEST = 1; // read from the master
 	const READ_LOCKING = 3; // READ_LATEST and "FOR UPDATE"
 
 	// Convenience constant for callers to explicitly request slave data