From bbadd9b3df186fa83f3183d163335b2ed7e79b66 Mon Sep 17 00:00:00 2001
From: Aaron Schulz <aschulz@wikimedia.org>
Date: Thu, 17 Oct 2013 11:35:00 -0700
Subject: [PATCH] Reduce excess lock contention and chance for failure on
 rename

* DB locks and transactions were getting held up by sometimes slow purges (10+ seconds)

Change-Id: I0eead60e8faf5aee6b2ddf59cfdd928f9c8083ff
---
 includes/filerepo/file/LocalFile.php | 21 +++++++++++++++------
 1 file changed, 15 insertions(+), 6 deletions(-)

diff --git a/includes/filerepo/file/LocalFile.php b/includes/filerepo/file/LocalFile.php
index 0c34f3e4f7..fe769be28c 100644
--- a/includes/filerepo/file/LocalFile.php
+++ b/includes/filerepo/file/LocalFile.php
@@ -1507,18 +1507,27 @@ class LocalFile extends File {
 
 		wfDebugLog( 'imagemove', "Finished moving {$this->name}" );
 
-		$this->purgeEverything();
-		foreach ( $archiveNames as $archiveName ) {
-			$this->purgeOldThumbnails( $archiveName );
-		}
+		// Purge the source and target files...
+		$oldTitleFile = wfLocalFile( $this->title );
+		$newTitleFile = wfLocalFile( $target );
+		// Hack: the lock()/unlock() pair is nested in a transaction so the locking is not
+		// tied to BEGIN/COMMIT. To avoid slow purges in the transaction, move them outside.
+		$this->getRepo()->getMasterDB()->onTransactionIdle(
+			function() use ( $oldTitleFile, $newTitleFile, $archiveNames ) {
+				$oldTitleFile->purgeEverything();
+				foreach ( $archiveNames as $archiveName ) {
+					$oldTitleFile->purgeOldThumbnails( $archiveName );
+				}
+				$newTitleFile->purgeEverything();
+			}
+		);
+
 		if ( $status->isOK() ) {
 			// Now switch the object
 			$this->title = $target;
 			// Force regeneration of the name and hashpath
 			unset( $this->name );
 			unset( $this->hashPath );
-			// Purge the new image
-			$this->purgeEverything();
 		}
 
 		return $status;
-- 
2.20.1