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That temporary index was created by running `git read-tree HEAD`. The resulting index had no useful cached stat data or fsmonitor-valid bits from the real index. When `run_add_p()` refreshed that temporary index before showing the first prompt, it could end up lstat(2)-ing every tracked file, even in a repository where `git diff` and `git restore -p` can use fsmonitor to avoid that work. Create the temporary index in-process instead. Use `unpack_trees()` to reset the real index contents to HEAD while writing the result to the temporary index path. For paths whose index entries already match HEAD, `oneway_merge()` reuses the existing cache entries, preserving their cached stat data and `CE_FSMONITOR_VALID` state. This makes the refresh performed by `run_add_p()` behave like the one used by `git restore -p`: unchanged paths can be skipped via fsmonitor instead of being scanned again. In a 206k file repository with `core.fsmonitor` enabled and a one-line change in one file, time to first prompt dropped from 34.774 seconds to 0.659 seconds. The new perf test file demonstrates similar improvements, with maen times for without- and with-fsmonitor cases dropping from 6.90 and 6.83 seconds to 0.55 and 0.28 seconds, respectively. Signed-off-by: Adam Johnson --- stash: reuse cached index entries in --patch temporary index Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-2306%2Fadamchainz%2Faj%2Foptimize-stash-patch-v2 Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-2306/adamchainz/aj/optimize-stash-patch-v2 Pull-Request: https://github.com/git/git/pull/2306 Range-diff vs v1: 1: b228160cc4 ! 1: 8785572c4d stash: reuse cached index entries in --patch temporary index @@ Commit message In a 206k file repository with `core.fsmonitor` enabled and a one-line change in one file, time to first prompt dropped from 34.774 seconds to - 0.659 seconds. + 0.659 seconds. The new perf test file demonstrates similar improvements, + with maen times for without- and with-fsmonitor cases dropping from 6.90 + and 6.83 seconds to 0.55 and 0.28 seconds, respectively. Signed-off-by: Adam Johnson @@ builtin/stash.c: static int reset_tree(struct object_id *i_tree, int update, int + struct lock_file lock_file = LOCK_INIT; + + repo_read_index_preload(the_repository, NULL, 0); -+ if (refresh_index(the_repository->index, REFRESH_QUIET, NULL, NULL, NULL)) -+ return -1; ++ refresh_index(the_repository->index, REFRESH_QUIET, NULL, NULL, NULL); + + hold_lock_file_for_update(&lock_file, index_path, LOCK_DIE_ON_ERROR); + @@ builtin/stash.c: static int stash_patch(struct stash_info *info, const struct pa goto done; } - ## t/t3904-stash-patch.sh ## -@@ t/t3904-stash-patch.sh: test_expect_success 'none of this moved HEAD' ' - verify_saved_head - ' - -+test_expect_success 'stash -p with unmodified tracked files present' ' -+ git reset --hard && -+ echo line1 >alpha && -+ echo line1 >beta && -+ git add alpha beta && -+ git commit -m "add alpha and beta" && -+ echo line2 >>alpha && -+ echo y | git stash -p && -+ echo line1 >expect && -+ test_cmp expect alpha && -+ test_cmp expect beta && -+ git stash pop && -+ printf "line1\nline2\n" >expect && -+ test_cmp expect alpha && -+ echo line1 >expect && -+ test_cmp expect beta + ## t/perf/p3904-stash-patch.sh (new) ## +@@ ++#!/bin/sh ++ ++test_description="Performance tests for git stash -p" ++ ++. ./perf-lib.sh ++ ++test_perf_fresh_repo ++ ++test_expect_success "setup" ' ++ mkdir files && ++ test_seq 1 100000 | while read i; do ++ echo "content $i" >files/$i.txt || return 1 ++ done && ++ git add files/ && ++ git commit -q -m "add tracked files" && ++ echo modified >files/1.txt +' + - test_expect_success 'stash -p with split hunk' ' - git reset --hard && - cat >test <<-\EOF && ++test_perf "stash -p, no fsmonitor" \ ++ --setup 'echo modified >files/1.txt' ' ++ printf "q\n" | git stash -p >/dev/null 2>&1 || true ++' ++ ++if test_have_prereq FSMONITOR_DAEMON ++then ++ test_expect_success "enable builtin fsmonitor" ' ++ git config core.fsmonitor true && ++ git fsmonitor--daemon start && ++ git update-index --fsmonitor && ++ git status >/dev/null 2>&1 ++ ' ++ ++ test_perf "stash -p, builtin fsmonitor" \ ++ --setup 'echo modified >files/1.txt && git status >/dev/null 2>&1' ' ++ printf "q\n" | git stash -p >/dev/null 2>&1 || true ++ ' ++ ++ test_expect_success "stop builtin fsmonitor" ' ++ git fsmonitor--daemon stop ++ ' ++fi ++ ++test_done builtin/stash.c | 70 +++++++++++++++++++++++++++++++++---- t/perf/p3904-stash-patch.sh | 43 +++++++++++++++++++++++ 2 files changed, 107 insertions(+), 6 deletions(-) create mode 100755 t/perf/p3904-stash-patch.sh diff --git a/builtin/stash.c b/builtin/stash.c index 32dbc97b47..c4809f299a 100644 --- a/builtin/stash.c +++ b/builtin/stash.c @@ -372,6 +372,56 @@ static int reset_tree(struct object_id *i_tree, int update, int reset) return 0; } +static int create_index_from_tree(const struct object_id *tree_id, + const char *index_path) +{ + int nr_trees = 1; + int ret = 0; + struct unpack_trees_options opts; + struct tree_desc t[MAX_UNPACK_TREES]; + struct tree *tree; + struct index_state dst_istate = INDEX_STATE_INIT(the_repository); + struct lock_file lock_file = LOCK_INIT; + + repo_read_index_preload(the_repository, NULL, 0); + refresh_index(the_repository->index, REFRESH_QUIET, NULL, NULL, NULL); + + hold_lock_file_for_update(&lock_file, index_path, LOCK_DIE_ON_ERROR); + + memset(&opts, 0, sizeof(opts)); + + tree = repo_parse_tree_indirect(the_repository, tree_id); + if (!tree || repo_parse_tree(the_repository, tree)) { + ret = -1; + goto done; + } + + init_tree_desc(t, &tree->object.oid, tree->buffer, tree->size); + + opts.head_idx = 1; + opts.src_index = the_repository->index; + opts.dst_index = &dst_istate; + opts.merge = 1; + opts.reset = UNPACK_RESET_PROTECT_UNTRACKED; + opts.fn = oneway_merge; + + if (unpack_trees(nr_trees, t, &opts)) { + ret = -1; + goto done; + } + + if (write_locked_index(&dst_istate, &lock_file, COMMIT_LOCK)) { + ret = error(_("unable to write new index file")); + goto done; + } + +done: + release_index(&dst_istate); + if (ret) + rollback_lock_file(&lock_file); + return ret; +} + static int diff_tree_binary(struct strbuf *out, struct object_id *w_commit) { struct child_process cp = CHILD_PROCESS_INIT; @@ -1321,18 +1371,26 @@ static int stash_patch(struct stash_info *info, const struct pathspec *ps, struct interactive_options *interactive_opts) { int ret = 0; - struct child_process cp_read_tree = CHILD_PROCESS_INIT; struct child_process cp_diff_tree = CHILD_PROCESS_INIT; + struct commit *head_commit; + const struct object_id *head_tree; struct index_state istate = INDEX_STATE_INIT(the_repository); char *old_index_env = NULL, *old_repo_index_file; remove_path(stash_index_path.buf); - cp_read_tree.git_cmd = 1; - strvec_pushl(&cp_read_tree.args, "read-tree", "HEAD", NULL); - strvec_pushf(&cp_read_tree.env, "GIT_INDEX_FILE=%s", - stash_index_path.buf); - if (run_command(&cp_read_tree)) { + head_commit = lookup_commit(the_repository, &info->b_commit); + if (!head_commit || repo_parse_commit(the_repository, head_commit)) { + ret = -1; + goto done; + } + head_tree = get_commit_tree_oid(head_commit); + if (!head_tree) { + ret = -1; + goto done; + } + + if (create_index_from_tree(head_tree, stash_index_path.buf)) { ret = -1; goto done; } diff --git a/t/perf/p3904-stash-patch.sh b/t/perf/p3904-stash-patch.sh new file mode 100755 index 0000000000..4cfce638be --- /dev/null +++ b/t/perf/p3904-stash-patch.sh @@ -0,0 +1,43 @@ +#!/bin/sh + +test_description="Performance tests for git stash -p" + +. ./perf-lib.sh + +test_perf_fresh_repo + +test_expect_success "setup" ' + mkdir files && + test_seq 1 100000 | while read i; do + echo "content $i" >files/$i.txt || return 1 + done && + git add files/ && + git commit -q -m "add tracked files" && + echo modified >files/1.txt +' + +test_perf "stash -p, no fsmonitor" \ + --setup 'echo modified >files/1.txt' ' + printf "q\n" | git stash -p >/dev/null 2>&1 || true +' + +if test_have_prereq FSMONITOR_DAEMON +then + test_expect_success "enable builtin fsmonitor" ' + git config core.fsmonitor true && + git fsmonitor--daemon start && + git update-index --fsmonitor && + git status >/dev/null 2>&1 + ' + + test_perf "stash -p, builtin fsmonitor" \ + --setup 'echo modified >files/1.txt && git status >/dev/null 2>&1' ' + printf "q\n" | git stash -p >/dev/null 2>&1 || true + ' + + test_expect_success "stop builtin fsmonitor" ' + git fsmonitor--daemon stop + ' +fi + +test_done base-commit: 7bcaabddcf68bd0702697da5904c3b68c52f94cf -- gitgitgadget