git/list[1] front-page[2] threads[3] people[4] search[5] about
 

[JGIT PATCH] Fix performance problem recently introduced to DeltaPackedObjectLoader

From
Shawn O. Pearce <spearce@spearce.org>
Date
Apr 27, 2009, 21:44 UTC
Message-ID
<1240868697-30971-1-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
Message 1 of 1 in “Fix performance problem recently introduced to DeltaPackedObjectLoader”
  1. Fix performance problem recently introduced to DeltaPackedObjectLoaderShawn O. Pearce, Apr 27, 2009

Read the whole thread, see it on lore, or plain text.

$ cat FOOTERMessages come from the public archive at lore.kernel.org/git, fetched every hour. The front page is chosen and written each morning by an AI editor and can be wrong; the threads themselves are the record. About and API. For agents: an MCP server at https://gitlist.dev/mcp, and any thread, story or person page as Markdown by adding .md to its URL (or sending Accept: text/markdown). Details in /llms.txt.