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3 commits
Author | SHA1 | Message | Date | |
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1d232d38bd |
ls-tree: test for the regression in 9c4d58ff2c
Add a test for the regression introduced in my |
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cab851c2f8 |
ls-tree: support --object-only option for "git-ls-tree"
'--object-only' is an alias for '--format=%(objectname)'. It cannot be used together other format-altering options like '--name-only', '--long' or '--format', they are mutually exclusive. The "--name-only" option outputs <filepath> only. Likewise, <objectName> is another high frequency used field, so implement '--object-only' option will bring intuitive and clear semantics for this scenario. Using '--format=%(objectname)' we can achieve a similar effect, but the former is with a lower learning cost(without knowing the format requirement of '--format' option). Even so, if a user is prefer to use "--format=%(objectname)", this is entirely welcome because they are not only equivalent in function, but also have almost identical performance. The reason is this commit also add the specific of "--format=%(objectname)" to the current fast-pathes (builtin formats) to avoid running unnecessary parsing mechanisms. The following performance benchmarks are based on torvalds/linux.git: When hit the fast-path: Benchmark 1: /opt/git/ls-tree-oid-only/bin/git ls-tree -r --object-only HEAD Time (mean ± σ): 83.6 ms ± 2.0 ms [User: 59.4 ms, System: 24.1 ms] Range (min … max): 80.4 ms … 87.2 ms 35 runs Benchmark 1: /opt/git/ls-tree-oid-only/bin/git ls-tree -r --format='%(objectname)' HEAD Time (mean ± σ): 84.1 ms ± 1.8 ms [User: 61.7 ms, System: 22.3 ms] Range (min … max): 80.9 ms … 87.5 ms 35 runs But for a customized format, it will be slower: Benchmark 1: /opt/git/ls-tree-oid-only/bin/git ls-tree -r --format='oid: %(objectname)' HEAD Time (mean ± σ): 96.5 ms ± 2.5 ms [User: 72.9 ms, System: 23.5 ms] Range (min … max): 93.1 ms … 104.1 ms 31 runs Helped-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Teng Long <dyroneteng@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com> |
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455923e0a1 |
ls-tree: introduce "--format" option
Add a --format option to ls-tree. It has an existing default output, and then --long and --name-only options to emit the default output along with the objectsize and, or to only emit object paths. Rather than add --type-only, --object-only etc. we can just support a --format using a strbuf_expand() similar to "for-each-ref --format". We might still add such options in the future for convenience. The --format implementation is slower than the existing code, but this change does not cause any performance regressions. We'll leave the existing show_tree() unchanged, and only run show_tree_fmt() in if a --format different than the hardcoded built-in ones corresponding to the existing modes is provided. I.e. something like the "--long" output would be much slower with this, mainly due to how we need to allocate various things to do with quote.c instead of spewing the output directly to stdout. The new option of '--format' comes from Ævar Arnfjörð Bjarmasonn's idea and suggestion, this commit makes modifications in terms of the original discussion on community [1]. In [1] there was a "GIT_TEST_LS_TREE_FORMAT_BACKEND" variable to ensure that we had test coverage for passing tests that would otherwise use show_tree() through show_tree_fmt(), and thus that the formatting mechanism could handle all the same cases as the non-formatting options. Somewhere in subsequent re-rolls of that we seem to have drifted away from what the goal of these tests should be. We're trying to ensure correctness of show_tree_fmt(). We can't tell if we "hit [the] fast-path" here, and instead of having an explicit test for that, we can just add it to something our "test_ls_tree_format" tests for. Here is the statistics about performance tests: 1. Default format (hitten the builtin formats): "git ls-tree <tree-ish>" vs "--format='%(mode) %(type) %(object)%x09%(file)'" $hyperfine --warmup=10 "/opt/git/master/bin/git ls-tree -r HEAD" Benchmark 1: /opt/git/master/bin/git ls-tree -r HEAD Time (mean ± σ): 105.2 ms ± 3.3 ms [User: 84.3 ms, System: 20.8 ms] Range (min … max): 99.2 ms … 113.2 ms 28 runs $hyperfine --warmup=10 "/opt/git/ls-tree-oid-only/bin/git ls-tree -r --format='%(mode) %(type) %(object)%x09%(file)' HEAD" Benchmark 1: /opt/git/ls-tree-oid-only/bin/git ls-tree -r --format='%(mode) %(type) %(object)%x09%(file)' HEAD Time (mean ± σ): 106.4 ms ± 2.7 ms [User: 86.1 ms, System: 20.2 ms] Range (min … max): 100.2 ms … 110.5 ms 29 runs 2. Default format includes object size (hitten the builtin formats): "git ls-tree -l <tree-ish>" vs "--format='%(mode) %(type) %(object) %(size:padded)%x09%(file)'" $hyperfine --warmup=10 "/opt/git/master/bin/git ls-tree -r -l HEAD" Benchmark 1: /opt/git/master/bin/git ls-tree -r -l HEAD Time (mean ± σ): 335.1 ms ± 6.5 ms [User: 304.6 ms, System: 30.4 ms] Range (min … max): 327.5 ms … 348.4 ms 10 runs $hyperfine --warmup=10 "/opt/git/ls-tree-oid-only/bin/git ls-tree -r --format='%(mode) %(type) %(object) %(size:padded)%x09%(file)' HEAD" Benchmark 1: /opt/git/ls-tree-oid-only/bin/git ls-tree -r --format='%(mode) %(type) %(object) %(size:padded)%x09%(file)' HEAD Time (mean ± σ): 337.2 ms ± 8.2 ms [User: 309.2 ms, System: 27.9 ms] Range (min … max): 328.8 ms … 349.4 ms 10 runs Links: [1] https://public-inbox.org/git/RFC-patch-6.7-eac299f06ff-20211217T131635Z-avarab@gmail.com/ [2] https://lore.kernel.org/git/cb717d08be87e3239117c6c667cb32caabaad33d.1646390152.git.dyroneteng@gmail.com/ Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Teng Long <dyroneteng@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com> |