[PATCH v2 0/2] grep: integrate with sparse index
- From
Shaoxuan Yuan <shaoxuan.yuan02@gmail.com>
- Date
- Aug 29, 2022, 23:28 UTC
- Message-ID
- <20220829232843.183711-1-shaoxuan.yuan02@gmail.com>
- In-Reply-To
- <20220817075633.217934-1-shaoxuan.yuan02@gmail.com>
Integrate `git-grep` with sparse-index and test the performance improvement.
Changes since v1 ----------------
* Rewrite the commit message for "builtin/grep.c: add --sparse option" to be clearer.
* Update the documentation (both in-code and man page) for --sparse.
* Add a few tests to test the new behavior (when _only_ --cached is supplied).
* Reformat the perf test results to not look like directly from p2000 tests.
* Put the "command_requires_full_index" lines right after parse_options().
* Add a pathspec test in t1092, and reword a few test documentations.
left-over-bits --------------
As Derrick suggested here [1], we can use tree traversing, for example `grep_tree()` in "builtin/grep.c", to grep each sparse directory, rather than expand the index directly, so we save some overheads.
However, when testing "specifying a pathspec to limit the scope of tree walking", my local branch Git does not show the contents within the pathspec because of pathspec mismatch (which is not expected, when "folder1/*" is used, "folder1/a" failed to match?!). And when the pathspec is not used, Git walks all the trees as expected, because `all_entries_interesting` is returned for the empty pathspec.
So I'm convinced that something is wrong with the pathspec matching logic within "builtin/grep.c", and I'm still working on it [2].
[1] https://lore.kernel.org/git/19dea639-389a-7258-e424-4912bde226df@github.com/ [2] https://github.com/ffyuanda/git/tree/grep/sparse-integration-v2.3-tree-walking
Shaoxuan Yuan (2): builtin/grep.c: add --sparse option builtin/grep.c: integrate with sparse index
Documentation/git-grep.txt | 5 +++- builtin/grep.c | 20 +++++++++++--- t/perf/p2000-sparse-operations.sh | 1 + t/t1092-sparse-checkout-compatibility.sh | 18 +++++++++++++ t/t7817-grep-sparse-checkout.sh | 34 +++++++++++++++++++----- 5 files changed, 68 insertions(+), 10 deletions(-)
Range-diff against v1:
1: bcac4dfc56 ! 1: 27c9341bca builtin/grep.c: add --sparse option
@@ Metadata
## Commit message ##
builtin/grep.c: add --sparse option
- Add a --sparse option to `git-grep`. This option is mainly used to:
+ Add a --sparse option to `git-grep`.
- If searching in the index (using --cached):
+ When the '--cached' option is used with the 'git grep' command, the
+ search is limited to the blobs found in the index, not in the worktree.
+ If the user has enabled sparse-checkout, this might present more results
+ than they would like, since the files outside of the sparse-checkout are
+ unlikely to be important to them.
- With --sparse, proceed the action when the current cache_entry is
- marked with SKIP_WORKTREE bit (the default is to skip this kind of
- entry). Before this patch, --cached itself can realize this action.
- Adding --sparse here grants the user finer control over sparse
- entries. If the user only wants to peak into the index without
- caring about sparse entries, --cached should suffice; if the user
- wants to peak into the index _and_ cares about sparse entries,
- combining --sparse with --cached can address this need.
+ Change the default behavior of 'git grep' to focus on the files within
+ the sparse-checkout definition. To enable the previous behavior, add a
+ '--sparse' option to 'git grep' that triggers the old behavior that
+ inspects paths outside of the sparse-checkout definition when paired
+ with the '--cached' option.
+ Helped-by: Derrick Stolee <derrickstolee@github.com>
Suggested-by: Victoria Dye <vdye@github.com>
Signed-off-by: Shaoxuan Yuan <shaoxuan.yuan02@gmail.com>
+ ## Documentation/git-grep.txt ##
+@@ Documentation/git-grep.txt: SYNOPSIS
+ [-f <file>] [-e] <pattern>
+ [--and|--or|--not|(|)|-e <pattern>...]
+ [--recurse-submodules] [--parent-basename <basename>]
+- [ [--[no-]exclude-standard] [--cached | --no-index | --untracked] | <tree>...]
++ [ [--[no-]exclude-standard] [--cached [--sparse] | --no-index | --untracked] | <tree>...]
+ [--] [<pathspec>...]
+
+ DESCRIPTION
+@@ Documentation/git-grep.txt: OPTIONS
+ Instead of searching tracked files in the working tree, search
+ blobs registered in the index file.
+
++--sparse::
++ Use with --cached. Search outside of sparse-checkout definition.
++
+ --no-index::
+ Search files in the current directory that is not managed by Git.
+
+
## builtin/grep.c ##
@@ builtin/grep.c: static pthread_cond_t cond_result;
@@ builtin/grep.c: static int grep_cache(struct grep_opt *opt,
- if (!cached && ce_skip_worktree(ce))
+ /*
-+ * If ce is a SKIP_WORKTREE entry, look into it when both
-+ * --sparse and --cached are given.
++ * Skip entries with SKIP_WORKTREE unless both --sparse and
++ * --cached are given.
+ */
+ if (!(grep_sparse && cached) && ce_skip_worktree(ce))
continue;
@@ builtin/grep.c: int cmd_grep(int argc, const char **argv, const char *prefix)
OPT_INTEGER('m', "max-count", &opt.max_count,
N_("maximum number of results per file")),
+ OPT_BOOL(0, "sparse", &grep_sparse,
-+ N_("search sparse contents and expand sparse index")),
++ N_("search the contents of files outside the sparse-checkout definition")),
OPT_END()
};
grep_prefix = prefix;
@@ t/t7817-grep-sparse-checkout.sh: test_expect_success 'grep searches unmerged fil
-test_expect_success 'grep --cached searches entries with the SKIP_WORKTREE bit' '
+test_expect_success 'grep --cached and --sparse searches entries with the SKIP_WORKTREE bit' '
++ cat >expect <<-EOF &&
++ a:text
++ EOF
++ git grep --cached "text" >actual &&
++ test_cmp expect actual &&
++
cat >expect <<-EOF &&
a:text
b:text
@@ t/t7817-grep-sparse-checkout.sh: test_expect_success 'grep --recurse-submodules
-test_expect_success 'grep --recurse-submodules --cached searches entries with the SKIP_WORKTREE bit' '
+test_expect_success 'grep --recurse-submodules --cached and --sparse searches entries with the SKIP_WORKTREE bit' '
++ cat >expect <<-EOF &&
++ a:text
++ sub/B/b:text
++ sub2/a:text
++ EOF
++ git grep --recurse-submodules --cached "text" >actual &&
++ test_cmp expect actual &&
++
cat >expect <<-EOF &&
a:text
b:text
@@ t/t7817-grep-sparse-checkout.sh: test_expect_success 'working tree grep does not
-test_expect_success 'grep --cached searches index entries with both CE_VALID and SKIP_WORKTREE' '
+test_expect_success 'grep --cached and --sparse searches index entries with both CE_VALID and SKIP_WORKTREE' '
++ cat >expect <<-EOF &&
++ a:text
++ EOF
++ test_when_finished "git update-index --no-assume-unchanged b" &&
++ git update-index --assume-unchanged b &&
++ git grep --cached text >actual &&
++ test_cmp expect actual &&
++
cat >expect <<-EOF &&
a:text
b:text
2: 48b21afb94 ! 2: cb16727c05 builtin/grep.c: integrate with sparse index
@@ Commit message
The p2000 tests demonstrate a ~99.4% execution time reduction for
`git grep` using a sparse index.
- Test HEAD~1 HEAD
+ Test Before After
-----------------------------------------------------------------------------
- 2000.78: git grep --cached bogus (full-v3) 0.019 0.018 (-5.2%)
- 2000.79: git grep --cached bogus (full-v4) 0.017 0.016 (-5.8%)
- 2000.80: git grep --cached bogus (sparse-v3) 0.29 0.0015 (-99.4%)
- 2000.81: git grep --cached bogus (sparse-v4) 0.30 0.0018 (-99.4%)
+ git grep --cached bogus (full-v3) 0.019 0.018 (-5.2%)
+ git grep --cached bogus (full-v4) 0.017 0.016 (-5.8%)
+ git grep --cached bogus (sparse-v3) 0.29 0.0015 (-99.4%)
+ git grep --cached bogus (sparse-v4) 0.30 0.0018 (-99.4%)
Optional reading about performance test results
-----------------------------------------------
@@ Commit message
## builtin/grep.c ##
@@ builtin/grep.c: static int grep_cache(struct grep_opt *opt,
- strbuf_addstr(&name, repo->submodule_prefix);
- }
-
-+ prepare_repo_settings(repo);
-+ repo->settings.command_requires_full_index = 0;
-+
if (repo_read_index(repo) < 0)
die(_("index file corrupt"));
@@ builtin/grep.c: static int grep_cache(struct grep_opt *opt,
for (nr = 0; nr < repo->index->cache_nr; nr++) {
const struct cache_entry *ce = repo->index->cache[nr];
+@@ builtin/grep.c: int cmd_grep(int argc, const char **argv, const char *prefix)
+ PARSE_OPT_KEEP_DASHDASH |
+ PARSE_OPT_STOP_AT_NON_OPTION);
+
++ if (the_repository->gitdir) {
++ prepare_repo_settings(the_repository);
++ the_repository->settings.command_requires_full_index = 0;
++ }
++
+ if (use_index && !startup_info->have_repository) {
+ int fallback = 0;
+ git_config_get_bool("grep.fallbacktonoindex", &fallback);
## t/perf/p2000-sparse-operations.sh ##
@@ t/perf/p2000-sparse-operations.sh: test_perf_on_all git read-tree -mu HEAD
@@ t/t1092-sparse-checkout-compatibility.sh: test_expect_success 'sparse index is n
ensure_not_expanded rm -r deep
'
-+test_expect_success 'grep expands index using --sparse' '
++test_expect_success 'grep with --sparse and --cached' '
+ init_repos &&
+
-+ # With --sparse and --cached, do not ignore sparse entries and
-+ # expand the index.
-+ test_all_match git grep --sparse --cached a
++ test_all_match git grep --sparse --cached a &&
++ test_all_match git grep --sparse --cached a -- "folder1/*"
+'
+
+test_expect_success 'grep is not expanded' '
@@ t/t1092-sparse-checkout-compatibility.sh: test_expect_success 'sparse index is n
+
+ ensure_not_expanded grep a &&
+ ensure_not_expanded grep a -- deep/* &&
-+ # grep does not match anything per se, so ! is used
++
++ # All files within the folder1/* pathspec are sparse,
++ # so this command does not find any matches
+ ensure_not_expanded ! grep a -- folder1/*
+'
+base-commit: 07ee72db0e97b5c233f8ada0abb412248c2f1c6f
-- 2.37.0