path: root/t/perf
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authorJeff King <>2016-01-22 22:29:30 (GMT)
committerJunio C Hamano <>2016-01-25 19:42:13 (GMT)
commita2d5156c2b0e6dbffc216b4a673156487a2f8b65 (patch)
tree6334583037d3290eda285269f9dac7b8c429013f /t/perf
parentffd036b1286687589f5ce5513ee69c06ee53691e (diff)
resolve_gitlink_ref: ignore non-repository paths
When we want to look up a submodule ref, we use get_ref_cache(path) to find or auto-create its ref cache. But if we feed a path that isn't actually a git repository, we blindly create the ref cache, and then may die deeper in the code when we try to access it. This is a problem because many callers speculatively feed us a path that looks vaguely like a repository, and expect us to tell them when it is not. This patch teaches resolve_gitlink_ref to reject non-repository paths without creating a ref_cache. This avoids the die(), and also performs better if you have a large number of these faux-submodule directories (because the ref_cache lookup is linear, under the assumption that there won't be a large number of submodules). To accomplish this, we also break get_ref_cache into two pieces: the lookup and auto-creation (the latter is lumped into create_ref_cache). This lets us first cheaply ask our cache "is it a submodule we know about?" If so, we can avoid repeating our filesystem lookup. So lookups of real submodules are not penalized; they examine the submodule's .git directory only once. The test in t3000 demonstrates a case where this improves correctness (we used to just die). The new perf case in p7300 shows off the speed improvement in an admittedly pathological repository: Test HEAD^ HEAD ---------------------------------------------------------------- 7300.4: ls-files -o 66.97(66.15+0.87) 0.33(0.08+0.24) -99.5% Signed-off-by: Jeff King <> Signed-off-by: Junio C Hamano <>
Diffstat (limited to 't/perf')
1 files changed, 4 insertions, 0 deletions
diff --git a/t/perf/ b/t/perf/
index ec94cdd..7c1888a 100755
--- a/t/perf/
+++ b/t/perf/
@@ -28,4 +28,8 @@ test_perf 'clean many untracked sub dirs, ignore nested git' '
git clean -n -q -f -f -d 100000_sub_dirs/
+test_perf 'ls-files -o' '
+ git ls-files -o