summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorJeff King <peff@peff.net>2015-11-06 06:24:29 (GMT)
committerJunio C Hamano <gitster@pobox.com>2015-11-06 17:35:49 (GMT)
commit348d4f2fc5d3c4f7ba47079b96676b4e2dd831fc (patch)
tree068baef549634129847efcc77f7aa8cf3d20566c
parentf34be46e47773d03e9d09641209121591a6b37c8 (diff)
downloadgit-348d4f2fc5d3c4f7ba47079b96676b4e2dd831fc.zip
git-348d4f2fc5d3c4f7ba47079b96676b4e2dd831fc.tar.gz
git-348d4f2fc5d3c4f7ba47079b96676b4e2dd831fc.tar.bz2
filter-branch: skip index read/write when possible
If the user specifies an index filter but not a tree filter, filter-branch cleverly avoids checking out the tree entirely. But we don't do the next level of optimization: if you have no index or tree filter, we do not need to read the index at all. This can greatly speed up cases where we are only changing the commit objects (e.g., cementing a graft into place). Here are numbers from the newly-added perf test: Test HEAD^ HEAD --------------------------------------------------------------- 7000.2: noop filter 13.81(4.95+0.83) 5.43(0.42+0.43) -60.7% Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
-rwxr-xr-xgit-filter-branch.sh23
-rwxr-xr-xt/perf/p7000-filter-branch.sh19
2 files changed, 40 insertions, 2 deletions
diff --git a/git-filter-branch.sh b/git-filter-branch.sh
index 27c9c54..d61f9ba 100755
--- a/git-filter-branch.sh
+++ b/git-filter-branch.sh
@@ -306,6 +306,15 @@ then
start_timestamp=$(date '+%s')
fi
+if test -n "$filter_index" ||
+ test -n "$filter_tree" ||
+ test -n "$filter_subdir"
+then
+ need_index=t
+else
+ need_index=
+fi
+
while read commit parents; do
git_filter_branch__commit_count=$(($git_filter_branch__commit_count+1))
@@ -313,7 +322,10 @@ while read commit parents; do
case "$filter_subdir" in
"")
- GIT_ALLOW_NULL_SHA1=1 git read-tree -i -m $commit
+ if test -n "$need_index"
+ then
+ GIT_ALLOW_NULL_SHA1=1 git read-tree -i -m $commit
+ fi
;;
*)
# The commit may not have the subdirectory at all
@@ -387,8 +399,15 @@ while read commit parents; do
} <../commit |
eval "$filter_msg" > ../message ||
die "msg filter failed: $filter_msg"
+
+ if test -n "$need_index"
+ then
+ tree=$(git write-tree)
+ else
+ tree="$commit^{tree}"
+ fi
workdir=$workdir @SHELL_PATH@ -c "$filter_commit" "git commit-tree" \
- $(git write-tree) $parentstr < ../message > ../map/$commit ||
+ "$tree" $parentstr < ../message > ../map/$commit ||
die "could not write rewritten commit"
done <../revs
diff --git a/t/perf/p7000-filter-branch.sh b/t/perf/p7000-filter-branch.sh
new file mode 100755
index 0000000..15ee5d1
--- /dev/null
+++ b/t/perf/p7000-filter-branch.sh
@@ -0,0 +1,19 @@
+#!/bin/sh
+
+test_description='performance of filter-branch'
+. ./perf-lib.sh
+
+test_perf_default_repo
+test_checkout_worktree
+
+test_expect_success 'mark bases for tests' '
+ git tag -f tip &&
+ git tag -f base HEAD~100
+'
+
+test_perf 'noop filter' '
+ git checkout --detach tip &&
+ git filter-branch -f base..HEAD
+'
+
+test_done