From: Derrick Stolee <dstolee@xxxxxxxxxxxxx>
By testing 'git -c core.fsmonitor= status -uno', we can check for the
simplest index operations that can be made sparse-aware. The necessary
implementation details are already integrated with sparse-checkout, so
modify command_requires_full_index to be zero for cmd_status().
By running the debugger for 'git status -uno' after that change, we find
two instances of ensure_full_index() that were added for extra safety,
but can be removed without issue.
In refresh_index(), we loop through the index entries. The
refresh_cache_ent() method copies the sparse directories into the
refreshed index without issue.
The loop within run_diff_files() skips things that are in stage 0 and
have skip-worktree enabled, so seems safe to disable ensure_full_index()
here.
This allows some cases of 'git status' to no longer expand a sparse
index to a full one, giving the following performance improvements for
p2000-sparse-checkout-operations.sh:
Test HEAD~1 HEAD
-----------------------------------------------------------------------------
2000.2: git status (full-index-v3) 0.38(0.36+0.07) 0.37(0.31+0.10) -2.6%
2000.3: git status (full-index-v4) 0.38(0.29+0.12) 0.37(0.30+0.11) -2.6%
2000.4: git status (sparse-index-v3) 2.43(2.33+0.14) 0.04(0.05+0.04) -98.4%
2000.5: git status (sparse-index-v4) 2.44(2.35+0.13) 0.05(0.04+0.07) -98.0%
Note that since HEAD~1 was expanding the sparse index by parsing trees,
it was artificially slower than the full index case. Thus, the 98%
improvement is misleading, and instead we should celebrate the 0.37s to
0.05s improvement of 82%. This is more indicative of the peformance
gains we are expecting by using a sparse index.
Note: we are dropping the assignment of core.fsmonitor here. This is not
necessary for the test script as we are not altering the config any
other way. Correct integration with FS Monitor will be validated in
later changes.
Signed-off-by: Derrick Stolee <dstolee@xxxxxxxxxxxxx>
---
builtin/commit.c | 3 +++
read-cache.c | 2 --
t/t1092-sparse-checkout-compatibility.sh | 12 ++++++++----
3 files changed, 11 insertions(+), 6 deletions(-)
diff --git a/builtin/commit.c b/builtin/commit.c
index cf0c36d1dcb2..e529da7beadd 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -1404,6 +1404,9 @@ int cmd_status(int argc, const char **argv, const char *prefix)
if (argc == 2 && !strcmp(argv[1], "-h"))
usage_with_options(builtin_status_usage, builtin_status_options);
+ prepare_repo_settings(the_repository);
+ the_repository->settings.command_requires_full_index = 0;
+
status_init_config(&s, git_status_config);
argc = parse_options(argc, argv, prefix,
builtin_status_options,
diff --git a/read-cache.c b/read-cache.c
index 6308234b4838..83e6bdef7604 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -1578,8 +1578,6 @@ int refresh_index(struct index_state *istate, unsigned int flags,
*/
preload_index(istate, pathspec, 0);
trace2_region_enter("index", "refresh", NULL);
- /* TODO: audit for interaction with sparse-index. */
- ensure_full_index(istate);
for (i = 0; i < istate->cache_nr; i++) {
struct cache_entry *ce, *new_entry;
int cache_errno = 0;
diff --git a/t/t1092-sparse-checkout-compatibility.sh b/t/t1092-sparse-checkout-compatibility.sh
index e488ef9bd941..380a085f8ec4 100755
--- a/t/t1092-sparse-checkout-compatibility.sh
+++ b/t/t1092-sparse-checkout-compatibility.sh
@@ -449,12 +449,16 @@ test_expect_success 'sparse-index is expanded and converted back' '
GIT_TRACE2_EVENT="$(pwd)/trace2.txt" GIT_TRACE2_EVENT_NESTING=10 \
git -C sparse-index -c core.fsmonitor="" reset --hard &&
test_region index convert_to_sparse trace2.txt &&
- test_region index ensure_full_index trace2.txt &&
+ test_region index ensure_full_index trace2.txt
+'
- rm trace2.txt &&
+test_expect_success 'sparse-index is not expanded' '
+ init_repos &&
+
+ rm -f trace2.txt &&
GIT_TRACE2_EVENT="$(pwd)/trace2.txt" GIT_TRACE2_EVENT_NESTING=10 \
- git -C sparse-index -c core.fsmonitor="" status -uno &&
- test_region index ensure_full_index trace2.txt
+ git -C sparse-index status -uno &&
+ test_region ! index ensure_full_index trace2.txt
'
test_done
--
gitgitgadget
