From: Aaron Schulz <aschulz@wikimedia.org>
Date: Thu, 11 Apr 2013 21:02:12 +0000 (-0700)
Subject: Pushed updateCategoryCounts() to transaction end to reduce contention.
X-Git-Tag: 1.31.0-rc.0~19991
X-Git-Url: http://git.cyclocoop.org/%24href?a=commitdiff_plain;h=c3e39d2b6d5f6895389bd9acb38c4dfa6b243890;p=lhc%2Fweb%2Fwiklou.git

Pushed updateCategoryCounts() to transaction end to reduce contention.

* This can really be a problem if locks are held during file related operations.

Change-Id: I00107ffc9951915d3af6002b258b3dae2de5fa92
---

diff --git a/includes/WikiPage.php b/includes/WikiPage.php
index 228f295b31..5aba23c725 100644
--- a/includes/WikiPage.php
+++ b/includes/WikiPage.php
@@ -3019,69 +3019,76 @@ class WikiPage implements Page, IDBAccessObject {
 	 * @param array $added   The names of categories that were added
 	 * @param array $deleted The names of categories that were deleted
 	 */
-	public function updateCategoryCounts( $added, $deleted ) {
-		$ns = $this->mTitle->getNamespace();
+	public function updateCategoryCounts( array $added, array $deleted ) {
+		$that = $this;
+		$method = __METHOD__;
 		$dbw = wfGetDB( DB_MASTER );
 
-		// First make sure the rows exist.  If one of the "deleted" ones didn't
-		// exist, we might legitimately not create it, but it's simpler to just
-		// create it and then give it a negative value, since the value is bogus
-		// anyway.
-		//
-		// Sometimes I wish we had INSERT ... ON DUPLICATE KEY UPDATE.
-		$insertCats = array_merge( $added, $deleted );
-		if ( !$insertCats ) {
-			// Okay, nothing to do
-			return;
-		}
+		// Do this at the end of the commit to reduce lock wait timeouts
+		$dbw->onTransactionPreCommitOrIdle(
+			function() use ( $dbw, $that, $method, $added, $deleted ) {
+				$ns = $that->getTitle()->getNamespace();
 
-		$insertRows = array();
+				// First make sure the rows exist.  If one of the "deleted" ones didn't
+				// exist, we might legitimately not create it, but it's simpler to just
+				// create it and then give it a negative value, since the value is bogus
+				// anyway.
+				//
+				// Sometimes I wish we had INSERT ... ON DUPLICATE KEY UPDATE.
+				$insertCats = array_merge( $added, $deleted );
+				if ( !$insertCats ) {
+					// Okay, nothing to do
+					return;
+				}
 
-		foreach ( $insertCats as $cat ) {
-			$insertRows[] = array(
-				'cat_id' => $dbw->nextSequenceValue( 'category_cat_id_seq' ),
-				'cat_title' => $cat
-			);
-		}
-		$dbw->insert( 'category', $insertRows, __METHOD__, 'IGNORE' );
+				$insertRows = array();
+				foreach ( $insertCats as $cat ) {
+					$insertRows[] = array(
+						'cat_id' => $dbw->nextSequenceValue( 'category_cat_id_seq' ),
+						'cat_title' => $cat
+					);
+				}
+				$dbw->insert( 'category', $insertRows, $method, 'IGNORE' );
 
-		$addFields = array( 'cat_pages = cat_pages + 1' );
-		$removeFields = array( 'cat_pages = cat_pages - 1' );
+				$addFields = array( 'cat_pages = cat_pages + 1' );
+				$removeFields = array( 'cat_pages = cat_pages - 1' );
 
-		if ( $ns == NS_CATEGORY ) {
-			$addFields[] = 'cat_subcats = cat_subcats + 1';
-			$removeFields[] = 'cat_subcats = cat_subcats - 1';
-		} elseif ( $ns == NS_FILE ) {
-			$addFields[] = 'cat_files = cat_files + 1';
-			$removeFields[] = 'cat_files = cat_files - 1';
-		}
+				if ( $ns == NS_CATEGORY ) {
+					$addFields[] = 'cat_subcats = cat_subcats + 1';
+					$removeFields[] = 'cat_subcats = cat_subcats - 1';
+				} elseif ( $ns == NS_FILE ) {
+					$addFields[] = 'cat_files = cat_files + 1';
+					$removeFields[] = 'cat_files = cat_files - 1';
+				}
 
-		if ( $added ) {
-			$dbw->update(
-				'category',
-				$addFields,
-				array( 'cat_title' => $added ),
-				__METHOD__
-			);
-		}
+				if ( $added ) {
+					$dbw->update(
+						'category',
+						$addFields,
+						array( 'cat_title' => $added ),
+						$method
+					);
+				}
 
-		if ( $deleted ) {
-			$dbw->update(
-				'category',
-				$removeFields,
-				array( 'cat_title' => $deleted ),
-				__METHOD__
-			);
-		}
+				if ( $deleted ) {
+					$dbw->update(
+						'category',
+						$removeFields,
+						array( 'cat_title' => $deleted ),
+						$method
+					);
+				}
 
-		foreach( $added as $catName ) {
-			$cat = Category::newFromName( $catName );
-			wfRunHooks( 'CategoryAfterPageAdded', array( $cat, $this ) );
-		}
-		foreach( $deleted as $catName ) {
-			$cat = Category::newFromName( $catName );
-			wfRunHooks( 'CategoryAfterPageRemoved', array( $cat, $this ) );
-		}
+				foreach( $added as $catName ) {
+					$cat = Category::newFromName( $catName );
+					wfRunHooks( 'CategoryAfterPageAdded', array( $cat, $that ) );
+				}
+				foreach( $deleted as $catName ) {
+					$cat = Category::newFromName( $catName );
+					wfRunHooks( 'CategoryAfterPageRemoved', array( $cat, $that ) );
+				}
+			}
+		);
 	}
 
 	/**