1 files changed, 89 insertions, 0 deletions
diff --git a/includes/DeferredUpdates.php b/includes/DeferredUpdates.php
new file mode 100644
index 00000000..262994e3
--- /dev/null
+++ b/includes/DeferredUpdates.php
@@ -0,0 +1,89 @@
+<?php
+/**
+ * Interface that deferrable updates should implement. Basically required so we
+ * can validate input on DeferredUpdates::addUpdate()
+ *
+ * @since 1.19
+ */
+interface DeferrableUpdate {
+	/**
+	 * Perform the actual work
+	 */
+	function doUpdate();
+}
+
+/**
+ * Class for mananging the deferred updates.
+ *
+ * @since 1.19
+ */
+class DeferredUpdates {
+	/**
+	 * Store of updates to be deferred until the end of the request.
+	 */
+	private static $updates = array();
+
+	/**
+	 * Add an update to the deferred list
+	 * @param $update DeferrableUpdate Some object that implements doUpdate()
+	 */
+	public static function addUpdate( DeferrableUpdate $update ) {
+		array_push( self::$updates, $update );
+	}
+
+	/**
+	 * HTMLCacheUpdates are the most common deferred update people use. This
+	 * is a shortcut method for that.
+	 * @see HTMLCacheUpdate::__construct()
+	 * @param $title
+	 * @param $table
+	 */
+	public static function addHTMLCacheUpdate( $title, $table ) {
+		self::addUpdate( new HTMLCacheUpdate( $title, $table ) );
+	}
+
+	/**
+	 * Do any deferred updates and clear the list
+	 *
+	 * @param $commit String: set to 'commit' to commit after every update to
+	 *                prevent lock contention
+	 */
+	public static function doUpdates( $commit = '' ) {
+		global $wgDeferredUpdateList;
+
+		wfProfileIn( __METHOD__ );
+
+		$updates = array_merge( $wgDeferredUpdateList, self::$updates );
+
+		// No need to get master connections in case of empty updates array
+		if ( !count( $updates ) ) {
+			wfProfileOut( __METHOD__ );
+			return;
+		}
+
+		$doCommit = $commit == 'commit';
+		if ( $doCommit ) {
+			$dbw = wfGetDB( DB_MASTER );
+		}
+
+		foreach ( $updates as $update ) {
+			$update->doUpdate();
+
+			if ( $doCommit && $dbw->trxLevel() ) {
+				$dbw->commit( __METHOD__ );
+			}
+		}
+
+		self::clearPendingUpdates();
+		wfProfileOut( __METHOD__ );
+	}
+
+	/**
+	 * Clear all pending updates without performing them. Generally, you don't
+	 * want or need to call this. Unit tests need it though.
+	 */
+	public static function clearPendingUpdates() {
+		global $wgDeferredUpdateList;
+		$wgDeferredUpdateList = self::$updates = array();
+	}
+}