diff-index uses the run_diff_index() function to generate its diff. This
function has been made sparse-index aware in the series that led to
8d2c3732 (Merge branch 'ld/sparse-diff-blame', 2021-12-21). Hence we can
just set the requires-full-index to false for "diff-index".
Performance metrics
Test HEAD~1 HEAD
----------------------------------------------------------------------------------------------
2000.2: echo >>a && git diff-index HEAD (full-v3) 0.09(0.06+0.04) 0.09(0.07+0.03) +0.0%
2000.3: echo >>a && git diff-index HEAD (full-v4) 0.09(0.06+0.04) 0.09(0.05+0.05) +0.0%
2000.4: echo >>a && git diff-index HEAD (sparse-v3) 0.37(0.31+0.06) 0.01(0.02+0.03) -97.3%
2000.5: echo >>a && git diff-index HEAD (sparse-v4) 0.30(0.26+0.05) 0.01(0.01+0.04) -96.7%
2000.6: git diff-index HEAD **a (full-v3) 0.06(0.05+0.01) 0.06(0.06+0.01) +0.0%
2000.7: git diff-index HEAD **a (full-v4) 0.06(0.05+0.01) 0.06(0.04+0.02) +0.0%
2000.8: git diff-index HEAD **a (sparse-v3) 0.29(0.25+0.03) 0.01(0.01+0.00) -96.6%
2000.9: git diff-index HEAD **a (sparse-v4) 0.37(0.34+0.02) 0.01(0.01+0.00) -97.3%
2000.10: git diff-index --cached HEAD (full-v3) 0.05(0.03+0.01) 0.05(0.03+0.02) +0.0%
2000.11: git diff-index --cached HEAD (full-v4) 0.05(0.03+0.01) 0.05(0.02+0.02) +0.0%
2000.12: git diff-index --cached HEAD (sparse-v3) 0.35(0.33+0.01) 0.01(0.00+0.00) -97.1%
2000.13: git diff-index --cached HEAD (sparse-v4) 0.35(0.32+0.02) 0.01(0.00+0.00) -97.1%
---
Sorry for the late reply. Got caught up in school work
* Fixed commit message
* Added check to expand index if needed (based on diff-files)
* Added pathspec based tests
builtin/diff-index.c | 9 +++++
t/perf/p2000-sparse-operations.sh | 3 ++
t/t1092-sparse-checkout-compatibility.sh | 44 ++++++++++++++++++++++++
3 files changed, 56 insertions(+)
diff --git a/builtin/diff-index.c b/builtin/diff-index.c
index 35dc9b23ee..e67cf5a1db 100644
--- a/builtin/diff-index.c
+++ b/builtin/diff-index.c
@@ -24,6 +24,14 @@ int cmd_diff_index(int argc, const char **argv, const char *prefix)
usage(diff_cache_usage);
git_config(git_diff_basic_config, NULL); /* no "diff" UI options */
+
+ prepare_repo_settings(the_repository);
+ the_repository->settings.command_requires_full_index = 0;
+
+ if (pathspec_needs_expanded_index(the_repository->index,
+ &rev.diffopt.pathspec))
+ ensure_full_index(the_repository->index);
+
repo_init_revisions(the_repository, &rev, prefix);
rev.abbrev = 0;
prefix = precompose_argv_prefix(argc, argv, prefix);
@@ -69,6 +77,7 @@ int cmd_diff_index(int argc, const char **argv, const char *prefix)
perror("repo_read_index");
return -1;
}
+
result = run_diff_index(&rev, option);
result = diff_result_code(&rev.diffopt, result);
release_revisions(&rev);
diff --git a/t/perf/p2000-sparse-operations.sh b/t/perf/p2000-sparse-operations.sh
index 3242cfe91a..62499d3aa8 100755
--- a/t/perf/p2000-sparse-operations.sh
+++ b/t/perf/p2000-sparse-operations.sh
@@ -125,5 +125,8 @@ test_perf_on_all git checkout-index -f --all
test_perf_on_all git update-index --add --remove $SPARSE_CONE/a
test_perf_on_all "git rm -f $SPARSE_CONE/a && git checkout HEAD -- $SPARSE_CONE/a"
test_perf_on_all git grep --cached --sparse bogus -- "f2/f1/f1/*"
+test_perf_on_all 'echo >>a && git diff-index HEAD'
+test_perf_on_all git diff-index HEAD "**a"
+test_perf_on_all git diff-index --cached HEAD
test_done
diff --git a/t/t1092-sparse-checkout-compatibility.sh b/t/t1092-sparse-checkout-compatibility.sh
index 801919009e..24bc716c48 100755
--- a/t/t1092-sparse-checkout-compatibility.sh
+++ b/t/t1092-sparse-checkout-compatibility.sh
@@ -1996,6 +1996,50 @@ test_expect_success 'sparse index is not expanded: rm' '
ensure_not_expanded rm -r deep
'
+test_expect_success 'sparse index is not expanded: diff-index' '
+ init_repos &&
+
+ echo "new" >>sparse-index/g &&
+ git -C sparse-index add g &&
+ git -C sparse-index commit -m "dummy" &&
+ ensure_not_expanded diff-index HEAD~1 &&
+
+ echo "text" >>sparse-index/deep/a &&
+
+ ensure_not_expanded diff-index HEAD deep/a &&
+ ensure_not_expanded diff-index HEAD deep/*
+'
+test_expect_success 'diff-index pathspec expands index when necessary' '
+ init_repos &&
+
+ echo "text" >>sparse-index/deep/a &&
+
+ # pathspec that should expand index
+ ! ensure_not_expanded diff-index "*/a" &&
+ ! ensure_not_expanded diff-index "**a"
+'
+
+test_expect_success 'diff-index with pathspec outside sparse definition' '
+ init_repos &&
+
+ test_sparse_match test_must_fail git diff-index HEAD folder2/a
+'
+
+test_expect_success 'match all: diff-index' '
+ init_repos &&
+
+ test_all_match git diff-index HEAD &&
+ write_script edit-contents <<-\EOF &&
+ echo text >>$1
+ EOF
+ run_on_all ../edit-contents g &&
+ run_on_all git add g &&
+ run_on_all git commit -m "two" &&
+ run_on_all rm g &&
+ test_all_match git diff-index HEAD &&
+ test_all_match git diff-index --cached HEAD~1
+'
+
test_expect_success 'grep with and --cached' '
init_repos &&
--
2.40.0
