From: Lessley Dennington Date: Tue, 23 Nov 2021 14:53:55 GMT Subject: Re: [PATCH v4 3/4] diff: enable and test the sparse index Message-ID: In-Reply-To: On 11/22/21 11:47 PM, Elijah Newren wrote: > On Mon, Nov 22, 2021 at 2:42 PM Lessley Dennington via GitGitGadget > wrote: >> >> From: Lessley Dennington >> >> Enable the sparse index within the 'git diff' command. Its implementation >> already safely integrates with the sparse index because it shares code >> with the 'git status' and 'git checkout' commands that were already >> integrated. For more details see: >> >> d76723e (status: use sparse-index throughout, 2021-07-14) >> 1ba5f45 (checkout: stop expanding sparse indexes, 2021-06-29) > > I preferred the references in your v3: > > d76723ee53 (status: use sparse-index throughout, 2021-07-14) > 1ba5f45132 (checkout: stop expanding sparse indexes, 2021-06-29) > > because 7-character abbreviations aren't very future proof; > 10-character seems better to me. > > (Very micro nit.) > Appreciate the pointer - I'll return to the old formatting for v5. >> >> The most interesting thing to do is to add tests that verify that 'git >> diff' behaves correctly when the sparse index is enabled. These cases are: >> >> 1. The index is not expanded for 'diff' and 'diff --staged' >> 2. 'diff' and 'diff --staged' behave the same in full checkout, sparse >> checkout, and sparse index repositories in the following partially-staged >> scenarios (i.e. the index, HEAD, and working directory differ at a given >> path): >> 1. Path is within sparse-checkout cone >> 2. Path is outside sparse-checkout cone >> 3. A merge conflict exists for paths outside sparse-checkout cone >> >> The `p2000` tests demonstrate a ~44% execution time reduction for 'git >> diff' and a ~86% execution time reduction for 'git diff --staged' using a >> sparse index: >> >> Test before after >> ------------------------------------------------------------- >> 2000.30: git diff (full-v3) 0.33 0.34 +3.0% >> 2000.31: git diff (full-v4) 0.33 0.35 +6.1% >> 2000.32: git diff (sparse-v3) 0.53 0.31 -41.5% >> 2000.33: git diff (sparse-v4) 0.54 0.29 -46.3% >> 2000.34: git diff --cached (full-v3) 0.07 0.07 +0.0% >> 2000.35: git diff --cached (full-v4) 0.07 0.08 +14.3% >> 2000.36: git diff --cached (sparse-v3) 0.28 0.04 -85.7% >> 2000.37: git diff --cached (sparse-v4) 0.23 0.03 -87.0% >> >> Co-authored-by: Derrick Stolee >> Signed-off-by: Derrick Stolee >> Signed-off-by: Lessley Dennington >> --- >> builtin/diff.c | 5 +++ >> t/perf/p2000-sparse-operations.sh | 2 ++ >> t/t1092-sparse-checkout-compatibility.sh | 46 ++++++++++++++++++++++++ >> 3 files changed, 53 insertions(+) >> >> diff --git a/builtin/diff.c b/builtin/diff.c >> index dd8ce688ba7..fa4683377eb 100644 >> --- a/builtin/diff.c >> +++ b/builtin/diff.c >> @@ -437,6 +437,11 @@ int cmd_diff(int argc, const char **argv, const char *prefix) >> >> prefix = setup_git_directory_gently(&nongit); >> >> + if (!nongit) { >> + prepare_repo_settings(the_repository); >> + the_repository->settings.command_requires_full_index = 0; >> + } >> + >> if (!no_index) { >> /* >> * Treat git diff with at least one path outside of the >> diff --git a/t/perf/p2000-sparse-operations.sh b/t/perf/p2000-sparse-operations.sh >> index bfd332120c8..5cf94627383 100755 >> --- a/t/perf/p2000-sparse-operations.sh >> +++ b/t/perf/p2000-sparse-operations.sh >> @@ -113,5 +113,7 @@ test_perf_on_all git checkout -f - >> test_perf_on_all git reset >> test_perf_on_all git reset --hard >> test_perf_on_all git reset -- does-not-exist >> +test_perf_on_all git diff >> +test_perf_on_all git diff --cached >> >> test_done >> diff --git a/t/t1092-sparse-checkout-compatibility.sh b/t/t1092-sparse-checkout-compatibility.sh >> index 44d5e11c762..53524660759 100755 >> --- a/t/t1092-sparse-checkout-compatibility.sh >> +++ b/t/t1092-sparse-checkout-compatibility.sh >> @@ -832,6 +832,52 @@ test_expect_success 'sparse-index is not expanded: merge conflict in cone' ' >> ) >> ' >> >> +test_expect_success 'sparse index is not expanded: diff' ' >> + init_repos && >> + >> + write_script edit-contents <<-\EOF && >> + echo text >>$1 >> + EOF >> + >> + # Add file within cone >> + test_sparse_match git sparse-checkout set deep && >> + run_on_all ../edit-contents deep/testfile && >> + test_all_match git add deep/testfile && >> + run_on_all ../edit-contents deep/testfile && >> + >> + test_all_match git diff && >> + test_all_match git diff --staged && >> + ensure_not_expanded diff && >> + ensure_not_expanded diff --staged && >> + >> + # Add file outside cone >> + test_all_match git reset --hard && >> + run_on_all mkdir newdirectory && >> + run_on_all ../edit-contents newdirectory/testfile && >> + test_sparse_match git sparse-checkout set newdirectory && >> + test_all_match git add newdirectory/testfile && >> + run_on_all ../edit-contents newdirectory/testfile && >> + test_sparse_match git sparse-checkout set && >> + >> + test_all_match git diff && >> + test_all_match git diff --staged && >> + ensure_not_expanded diff && >> + ensure_not_expanded diff --staged && >> + >> + # Merge conflict outside cone >> + # The sparse checkout will report a warning that is not in the >> + # full checkout, so we use `run_on_all` instead of >> + # `test_all_match` >> + run_on_all git reset --hard && >> + test_all_match git checkout merge-left && >> + test_all_match test_must_fail git merge merge-right && >> + >> + test_all_match git diff && >> + test_all_match git diff --staged && >> + ensure_not_expanded diff && >> + ensure_not_expanded diff --staged > > You've changed some of the --staged to --cached, but based on Junio's > comments on the previous round, you probably want to convert the > others too. > Will do for v5. >> +' >> + >> # NEEDSWORK: a sparse-checkout behaves differently from a full checkout >> # in this scenario, but it shouldn't. >> test_expect_success 'reset mixed and checkout orphan' ' >> -- >> gitgitgadget >>