jgit/org.eclipse.jgit
Luca Milanesio e4529cd39c PackWriterBitmapPreparer: do not include annotated tags in bitmap
The annotated tags should be excluded from the bitmap associated
with the heads-only packfile. However, this was not happening
because of the check of exclusion of the peeled object instead
of the objectId to be excluded from the bitmap.

Sample use-case:

refs/heads/main
  ^
  |
 commit1 <-- commit2 <- annotated-tag1 <- tag1
  ^
  |
 commit0

When creating a bitmap for the above commit graph, before this
change all the commits are included (3 bitmaps), which is
incorrect, because all commits reachable from annotated tags
should not be included.

The heads-only bitmap should include only commit0 and commit1
but because PackWriterBitPreparer was checking for the peeled
pointer of tag1 to be excluded (commit2) which was not found in
the list of tags to exclude (annotated-tag1), the commit2 was
included, even if it wasn't reachable only from the head.

Add an additional check for exclusion of the original objectId
for allowing the exclusion of annotated tags and their pointed
commits. Add one specific test associated with an annotated tag
for making sure that this use-case is covered also.

Example repository benchmark for measuring the improvement:
# refs: 400k (2k heads, 88k tags, 310k changes)
# objects: 11M (88k of them are annotate tags)
# packfiles: 2.7G

Before this change:
GC time: 5h
clone --bare time: 7 mins

After this change:
GC time: 20 mins
clone --bare time: 3 mins

Bug: 581267
Signed-off-by: Luca Milanesio <luca.milanesio@gmail.com>
Change-Id: Iff2bfc6587153001837220189a120ead9ac649dc
2023-01-31 14:15:56 +01:00
..
.settings Speedup GC listing objects referenced from reflogs 2023-01-23 17:19:14 +01:00
META-INF Add missing package import javax.management to org.eclipse.jgit 2022-06-17 13:49:59 +02:00
findBugs [spotbugs] Silence NP_BOOLEAN_RETURN_NULL in IgnoreNode#checkIgnored 2020-12-22 10:52:59 +01:00
resources/org/eclipse/jgit AmazonS3: Add support for AWS API signature version 4 2022-06-13 09:44:23 +02:00
src/org/eclipse/jgit PackWriterBitmapPreparer: do not include annotated tags in bitmap 2023-01-31 14:15:56 +01:00
.classpath
.fbprefs
.gitignore
.project
BUILD Fix stamping to produce stable file timestamps 2020-12-14 15:45:29 +01:00
about.html SHA-1: collision detection support 2017-02-28 16:38:43 -08:00
build.properties Add "resources/" as a source folder 2010-06-05 14:39:27 +02:00
plugin.properties Fix bundle localization of Apache SSH bundle 2019-06-21 17:54:06 +02:00
pom.xml Prepare 5.13.2-SNAPSHOT builds 2022-06-14 00:41:18 +02:00