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author | Shuqi Liang <cheskaqiqi@gmail.com> | 2023-05-18 18:44:54 +0300 |
---|---|---|
committer | Junio C Hamano <gitster@pobox.com> | 2023-05-18 20:40:33 +0300 |
commit | 48c5fbfb8976c733b7ea550675594a77777db2fa (patch) | |
tree | 3745cd4f03c7cf053682e73dca9c3a610b0027de /t/perf | |
parent | 0df2c180904f6b709766f9c24669a9d01543f915 (diff) |
diff-tree: integrate with sparse index
The index is read in 'cmd_diff_tree' at two points:
1. The first index read was added in fd66bcc31ff (diff-tree: read the
index so attribute checks work in bare repositories, 2017-12-06) to deal
with reading '.gitattributes' content. 77efbb366ab (attr: be careful
about sparse directories, 2021-09-08) established that, in a sparse
index, we do _not_ try to load a '.gitattributes' file from within a
sparse directory.
2. The second index access point is involved in rename detection,
specifically when reading from stdin.This was initially added in
f0c6b2a2fd9 ([PATCH] Optimize diff-tree -[CM]--stdin, 2005-05-27), where
'setup' was set to 'DIFF_SETUP_USE_SIZE_CACHE |DIFF_SETUP_USE_CACHE'.
That assignment was later modified to drop the'DIFF_SETUP_USE_CACHE' in
ff7fe37b053 (diff.c: move read_index() code back to the caller,
2018-08-13).However, 'DIFF_SETUP_USE_SIZE_CACHE' seems to be unused as
of 6e0b8ed6d35 (diff.c: do not use a separate "size cache"., 2007-05-07)
and nothing about 'detect_rename' otherwise indicates index usage.
Hence we can just set the requires-full-index to false for "diff-tree".
Add tests that verify that 'git diff-tree' behaves correctly when the
sparse index is enabled and test to ensure the index is not expanded.
The `p2000` tests demonstrate a ~98% execution time reduction for
'git diff-tree' using a sparse index:
Test before after
-----------------------------------------------------------------------
2000.94: git diff-tree HEAD (full-v3) 0.05 0.04 -20.0%
2000.95: git diff-tree HEAD (full-v4) 0.06 0.05 -16.7%
2000.96: git diff-tree HEAD (sparse-v3) 0.59 0.01 -98.3%
2000.97: git diff-tree HEAD (sparse-v4) 0.61 0.01 -98.4%
2000.98: git diff-tree HEAD -- f2/f4/a (full-v3) 0.05 0.05 +0.0%
2000.99: git diff-tree HEAD -- f2/f4/a (full-v4) 0.05 0.04 -20.0%
2000.100: git diff-tree HEAD -- f2/f4/a (sparse-v3) 0.58 0.01 -98.3%
2000.101: git diff-tree HEAD -- f2/f4/a (sparse-v4) 0.55 0.01 -98.2%
Helped-by: Victoria Dye <vdye@github.com>
Signed-off-by: Shuqi Liang <cheskaqiqi@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 't/perf')
-rwxr-xr-x | t/perf/p2000-sparse-operations.sh | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/t/perf/p2000-sparse-operations.sh b/t/perf/p2000-sparse-operations.sh index 901cc493ef..5a11910189 100755 --- a/t/perf/p2000-sparse-operations.sh +++ b/t/perf/p2000-sparse-operations.sh @@ -131,5 +131,7 @@ test_perf_on_all git describe --dirty test_perf_on_all 'echo >>new && git describe --dirty' test_perf_on_all git diff-files test_perf_on_all git diff-files -- $SPARSE_CONE/a +test_perf_on_all git diff-tree HEAD +test_perf_on_all git diff-tree HEAD -- $SPARSE_CONE/a test_done |