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[JGIT PATCH 01/13] Fix performance problem recently introduced to DeltaPackedObjectLoader

From
Shawn O. Pearce <spearce@spearce.org>
Date
Apr 28, 2009, 21:12 UTC
Message-ID
<1240953146-12878-2-git-send-email-spearce@spearce.org>
In-Reply-To
<1240953146-12878-1-git-send-email-spearce@spearce.org>

In fe6c8248e1ed6bd9db76a8314103081a02d55393 ("Fully materialize an ObjectLoader before returning it from ObjectDatabase") I missed a crucial return call here in DeltaPackedObjectLoadeder. That one missing line caused cache hits in the UnpackedObjectCache to then fall through and unpack the delta base, and apply the delta onto it, ignoring the fact that we had a successful cache hit.

When packing and serving e.g. the Linux kernel repository this resulted in a 10x increase in the number of WindowCache.get() invocations we saw, as the UnpackedObjectCache was useless.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
---
 .../spearce/jgit/lib/DeltaPackedObjectLoader.java  |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
diff --git a/org.spearce.jgit/src/org/spearce/jgit/lib/DeltaPackedObjectLoader.java b/org.spearce.jgit/src/org/spearce/jgit/lib/DeltaPackedObjectLoader.java
index 8194d94..7d3f30d 100644
--- a/org.spearce.jgit/src/org/spearce/jgit/lib/DeltaPackedObjectLoader.java
+++ b/org.spearce.jgit/src/org/spearce/jgit/lib/DeltaPackedObjectLoader.java
@@ -69,6 +69,7 @@ public void materialize(final WindowCursor curs) throws IOException {
 				objectType = cache.type;
 				objectSize = cache.data.length;
 				cachedBytes = cache.data;
+				return;
 			}
 		}
 
-- 
1.6.3.rc1.205.g37f8
Previous: Shawn O. PearceNext: Shawn O. Pearce
Message 2 of 18 in “Misc. bug fixes and cleanups”
  1. 00/13 Misc. bug fixes and cleanupsShawn O. Pearce, Apr 28, 2009
  2. 01/13 Fix performance problem recently introduced to DeltaPackedObjectLoaderShawn O. Pearce, Apr 28, 2009
  3. 02/13 Don't use ByteWindows when checking pack file headers/footersShawn O. Pearce, Apr 28, 2009
  4. 03/13 Rewrite WindowCache to be easier to follow and maintainShawn O. Pearce, Apr 28, 2009
  5. 04/13 Document the IllegalArgumentException thrown by WindowCache.reconfigureShawn O. Pearce, Apr 28, 2009
  6. 05/13 Create the new WindowCache before clearing the old oneShawn O. Pearce, Apr 28, 2009
  7. 06/13 Better handle concurrent reads during a WindowCache reconfigurationShawn O. Pearce, Apr 28, 2009
  8. 07/13 Clear dead OffsetCache cells when clearing a referenceShawn O. Pearce, Apr 28, 2009
  9. 08/13 Work around Sun JVM bug "Cleared SoftReference not added to queue"Shawn O. Pearce, Apr 28, 2009
  10. 09/13 Replace inefficient new String(String) constructor to silence FindBugsShawn O. Pearce, Apr 28, 2009
  11. 10/13 Replace inefficient new Long(long) constructor to silence FindBugsShawn O. Pearce, Apr 28, 2009
  12. 11/13 Change IndexPack to use ObjectIdSubclassMap instead of ObjectIdMapShawn O. Pearce, Apr 28, 2009
  13. 12/13 Use getCachedBytes in IndexPack to avoid an unnecessary copyShawn O. Pearce, Apr 28, 2009
  14. 13/13 Remove ObjectIdMap from the JGit libraryShawn O. Pearce, Apr 28, 2009
  15. Robin RosenbergApr 29, 2009
  16. 12/11 Add a test for LongMap, IndexPack's helper classShawn O. Pearce, Apr 29, 2009
  17. Robin RosenbergApr 29, 2009
  18. Shawn O. PearceApr 29, 2009

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