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2021-08-09revision: avoid hitting packfiles when commits are in commit-graphLibravatar Patrick Steinhardt1-10/+8
When queueing references in git-rev-list(1), we try to optimize parsing of commits via the commit-graph. To do so, we first look up the object's type, and if it is a commit we call `repo_parse_commit()` instead of `parse_object()`. This is quite inefficient though given that we're always uncompressing the object header in order to determine the type. Instead, we can opportunistically search the commit-graph for the object ID: in case it's found, we know it's a commit and can directly fill in the commit object without having to uncompress the object header. Expose a new function `lookup_commit_in_graph()`, which tries to find a commit in the commit-graph by ID, and convert `get_reference()` to use this function. This provides a big performance win in cases where we load references in a repository with lots of references pointing to commits. The following has been executed in a real-world repository with about 2.2 million refs: Benchmark #1: HEAD~: rev-list --unsorted-input --objects --quiet --not --all --not $newrev Time (mean ± σ): 4.458 s ± 0.044 s [User: 4.115 s, System: 0.342 s] Range (min … max): 4.409 s … 4.534 s 10 runs Benchmark #2: HEAD: rev-list --unsorted-input --objects --quiet --not --all --not $newrev Time (mean ± σ): 3.089 s ± 0.015 s [User: 2.768 s, System: 0.321 s] Range (min … max): 3.061 s … 3.105 s 10 runs Summary 'HEAD: rev-list --unsorted-input --objects --quiet --not --all --not $newrev' ran 1.44 ± 0.02 times faster than 'HEAD~: rev-list --unsorted-input --objects --quiet --not --all --not $newrev' Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-08-09revision: stop retrieving reference twiceLibravatar Patrick Steinhardt1-1/+1
When queueing up references for the revision walk, `handle_one_ref()` will resolve the reference's object ID via `get_reference()` and then queue the ID as pending object via `add_pending_oid()`. But given that `add_pending_oid()` is only a thin wrapper around `add_pending_object()` which fist calls `get_reference()`, we effectively resolve the reference twice and thus duplicate some of the work. Fix the issue by instead calling `add_pending_object()` directly, which takes the already-resolved object as input. In a repository with lots of refs, this translates into a near 10% speedup: Benchmark #1: HEAD~: rev-list --unsorted-input --objects --quiet --not --all --not $newrev Time (mean ± σ): 5.015 s ± 0.038 s [User: 4.698 s, System: 0.316 s] Range (min … max): 4.970 s … 5.089 s 10 runs Benchmark #2: HEAD: rev-list --unsorted-input --objects --quiet --not --all --not $newrev Time (mean ± σ): 4.606 s ± 0.029 s [User: 4.260 s, System: 0.345 s] Range (min … max): 4.565 s … 4.657 s 10 runs Summary 'HEAD: rev-list --unsorted-input --objects --quiet --not --all --not $newrev' ran 1.09 ± 0.01 times faster than 'HEAD~: rev-list --unsorted-input --objects --quiet --not --all --not $newrev' Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-08-09connected: do not sort input revisionsLibravatar Patrick Steinhardt1-0/+9
In order to compute whether objects reachable from a set of tips are all connected, we do a revision walk with these tips as positive references and `--not --all`. `--not --all` will cause the revision walk to load all preexisting references as uninteresting, which can be very expensive in repositories with many references. Benchmarking the git-rev-list(1) command highlights that by far the most expensive single phase is initial sorting of the input revisions: after all references have been loaded, we first sort commits by author date. In a real-world repository with about 2.2 million references, it makes up about 40% of the total runtime of git-rev-list(1). Ultimately, the connectivity check shouldn't really bother about the order of input revisions at all. We only care whether we can actually walk all objects until we hit the cut-off point. So sorting the input is a complete waste of time. Introduce a new "--unsorted-input" flag to git-rev-list(1) which will cause it to not sort the commits and adjust the connectivity check to always pass the flag. This results in the following speedups, executed in a clone of gitlab-org/gitlab [1]: Benchmark #1: git rev-list --objects --quiet --not --all --not $(cat newrev) Time (mean ± σ): 7.639 s ± 0.065 s [User: 7.304 s, System: 0.335 s] Range (min … max): 7.543 s … 7.742 s 10 runs Benchmark #2: git rev-list --unsorted-input --objects --quiet --not --all --not $newrev Time (mean ± σ): 4.995 s ± 0.044 s [User: 4.657 s, System: 0.337 s] Range (min … max): 4.909 s … 5.048 s 10 runs Summary 'git rev-list --unsorted-input --objects --quiet --not --all --not $(cat newrev)' ran 1.53 ± 0.02 times faster than 'git rev-list --objects --quiet --not --all --not $newrev' [1]: https://gitlab.com/gitlab-org/gitlab.git. Note that not all refs are visible to clients. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-08-05revision: separate walk and unsorted flagsLibravatar Patrick Steinhardt1-4/+5
The `--no-walk` flag supports two modes: either it sorts the revisions given as input input or it doesn't. This is reflected in a single `no_walk` flag, which reflects one of the three states "walk", "don't walk but without sorting" and "don't walk but with sorting". Split up the flag into two separate bits, one indicating whether we should walk or not and one indicating whether the input should be sorted or not. This will allow us to more easily introduce a new flag `--unsorted-input`, which only impacts the sorting bit. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-06-11add_pending_object_with_path(): work around "gcc -O3" complaintLibravatar Jeff King1-2/+3
When compiling with -O3, some gcc versions (10.2.1 here) complain about an out-of-bounds subscript: revision.c: In function ‘do_add_index_objects_to_pending’: revision.c:321:22: error: array subscript [1, 2147483647] is outside array bounds of ‘char[1]’ [-Werror=array-bounds] 321 | if (0 < len && name[len] && buf.len) | ~~~~^~~~~ The "len" parameter here comes from calling interpret_branch_name(), which intends to return the number of characters of "name" it parsed. But the compiler doesn't realize this. It knows the size of the empty string "name" passed in from do_add_index_objects_to_pending(), but it has no clue that the "len" we get back will be constrained to "0" in that case. And I don't think the warning is telling us about some subtle or clever bug. The implementation of interpret_branch_name() is in another file entirely, and the compiler can't see it (you can even verify there is no clever LTO going on by replacing it with "return 0" and still getting the warning). We can work around this by replacing our "did we hit the trailing NUL" subscript dereference with a length check. We do not even have to pay the cost for an extra strlen(), as we can pass our new length into interpret_branch_name(), which was converting our "0" into a call to strlen() anyway. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-05-07Merge branch 'ah/plugleaks'Libravatar Junio C Hamano1-7/+10
Plug various leans reported by LSAN. * ah/plugleaks: builtin/rm: avoid leaking pathspec and seen builtin/rebase: release git_format_patch_opt too builtin/for-each-ref: free filter and UNLEAK sorting. mailinfo: also free strbuf lists when clearing mailinfo builtin/checkout: clear pending objects after diffing builtin/check-ignore: clear_pathspec before returning builtin/bugreport: don't leak prefixed filename branch: FREE_AND_NULL instead of NULL'ing real_ref bloom: clear each bloom_key after use ls-files: free max_prefix when done wt-status: fix multiple small leaks revision: free remainder of old commit list in limit_list
2021-05-07Merge branch 'ps/rev-list-object-type-filter'Libravatar Junio C Hamano1-2/+2
"git rev-list" learns the "--filter=object:type=<type>" option, which can be used to exclude objects of the given kind from the packfile generated by pack-objects. * ps/rev-list-object-type-filter: rev-list: allow filtering of provided items pack-bitmap: implement combined filter pack-bitmap: implement object type filter list-objects: implement object type filter list-objects: support filtering by tag and commit list-objects: move tag processing into its own function revision: mark commit parents as NOT_USER_GIVEN uploadpack.txt: document implication of `uploadpackfilter.allow`
2021-04-30Merge branch 'ds/sparse-index-protections'Libravatar Junio C Hamano1-0/+2
Builds on top of the sparse-index infrastructure to mark operations that are not ready to mark with the sparse index, causing them to fall back on fully-populated index that they always have worked with. * ds/sparse-index-protections: (47 commits) name-hash: use expand_to_path() sparse-index: expand_to_path() name-hash: don't add directories to name_hash revision: ensure full index resolve-undo: ensure full index read-cache: ensure full index pathspec: ensure full index merge-recursive: ensure full index entry: ensure full index dir: ensure full index update-index: ensure full index stash: ensure full index rm: ensure full index merge-index: ensure full index ls-files: ensure full index grep: ensure full index fsck: ensure full index difftool: ensure full index commit: ensure full index checkout: ensure full index ...
2021-04-28revision: free remainder of old commit list in limit_listLibravatar Andrzej Hunt1-7/+10
limit_list() iterates over the original revs->commits list, and consumes many of its entries via pop_commit. However we might stop iterating over the list early (e.g. if we realise that the rest of the list is uninteresting). If we do stop iterating early, list will be pointing to the unconsumed portion of revs->commits - and we need to free this list to avoid a leak. (revs->commits itself will be an invalid pointer: it will have been free'd during the first pop_commit.) However the list pointer is later reused to iterate over our new list, but only for the limiting_can_increase_treesame() branch. We therefore need to introduce a new variable for that branch - and while we're here we can rename the original list to original_list as that makes its purpose more obvious. This leak was found while running t0090. It's not likely to be very impactful, but it can happen quite early during some checkout invocations, and hence seems to be worth fixing: Direct leak of 16 byte(s) in 1 object(s) allocated from: #0 0x49a85d in malloc ../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3 #1 0x9ac084 in do_xmalloc wrapper.c:41:8 #2 0x9ac05a in xmalloc wrapper.c:62:9 #3 0x7175d6 in commit_list_insert commit.c:540:33 #4 0x71800f in commit_list_insert_by_date commit.c:604:9 #5 0x8f8d2e in process_parents revision.c:1128:5 #6 0x8f2f2c in limit_list revision.c:1418:7 #7 0x8f210e in prepare_revision_walk revision.c:3577:7 #8 0x514170 in orphaned_commit_warning builtin/checkout.c:1185:6 #9 0x512f05 in switch_branches builtin/checkout.c:1250:3 #10 0x50f8de in checkout_branch builtin/checkout.c:1646:9 #11 0x50ba12 in checkout_main builtin/checkout.c:2003:9 #12 0x5086c0 in cmd_checkout builtin/checkout.c:2055:8 #13 0x4cd91d in run_builtin git.c:467:11 #14 0x4cb5f3 in handle_builtin git.c:719:3 #15 0x4ccf47 in run_argv git.c:808:4 #16 0x4caf49 in cmd_main git.c:939:19 #17 0x69dc0e in main common-main.c:52:11 #18 0x7faaabd0e349 in __libc_start_main (/lib64/libc.so.6+0x24349) Indirect leak of 48 byte(s) in 3 object(s) allocated from: #0 0x49a85d in malloc ../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3 #1 0x9ac084 in do_xmalloc wrapper.c:41:8 #2 0x9ac05a in xmalloc wrapper.c:62:9 #3 0x717de6 in commit_list_append commit.c:1609:35 #4 0x8f1f9b in prepare_revision_walk revision.c:3554:12 #5 0x514170 in orphaned_commit_warning builtin/checkout.c:1185:6 #6 0x512f05 in switch_branches builtin/checkout.c:1250:3 #7 0x50f8de in checkout_branch builtin/checkout.c:1646:9 #8 0x50ba12 in checkout_main builtin/checkout.c:2003:9 #9 0x5086c0 in cmd_checkout builtin/checkout.c:2055:8 #10 0x4cd91d in run_builtin git.c:467:11 #11 0x4cb5f3 in handle_builtin git.c:719:3 #12 0x4ccf47 in run_argv git.c:808:4 #13 0x4caf49 in cmd_main git.c:939:19 #14 0x69dc0e in main common-main.c:52:11 #15 0x7faaabd0e349 in __libc_start_main (/lib64/libc.so.6+0x24349) Signed-off-by: Andrzej Hunt <ajrhunt@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-14revision: ensure full indexLibravatar Derrick Stolee1-0/+2
Before iterating over all index entries, ensure that a sparse index is expanded to a full index to avoid unexpected behavior. This case could be integrated later by ensuring that we walk the tree in the sparse-directory entry, but the current behavior is only expecting blobs. Save this integration for later when it can be properly tested. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Reviewed-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-13revision: avoid parsing with --exclude-promisor-objectsLibravatar Jeff King1-1/+1
When --exclude-promisor-objects is given, before traversing any objects we iterate over all of the objects in any promisor packs, marking them as UNINTERESTING and SEEN. We turn the oid we get from iterating the pack into an object with parse_object(), but this has two problems: - it's slow; we are zlib inflating (and reconstructing from deltas) every byte of every object in the packfile - it leaves the tree buffers attached to their structs, which means our heap usage will grow to store every uncompressed tree simultaneously. This can be gigabytes. We can obviously fix the second by freeing the tree buffers after we've parsed them. But we can observe that the function doesn't look at the object contents at all! The only reason we call parse_object() is that we need a "struct object" on which to set the flags. There are two options here: - we can look up just the object type via oid_object_info(), and then call the appropriate lookup_foo() function - we can call lookup_unknown_object(), which gives us an OBJ_NONE struct (which will get auto-converted later by object_as_type() via calls to lookup_commit(), etc). The first one is closer to the current code, but we do pay the price to look up the type for each object. The latter should be more efficient in CPU, though it wastes a little bit of memory (the "unknown" object structs are a union of all object types, so some of the structs are bigger than they need to be). It also runs the risk of triggering a latent bug in code that calls lookup_object() directly but isn't ready to handle OBJ_NONE (such code would already be buggy, but we use lookup_unknown_object() infrequently enough that it might be hiding). I went with the second option here. I don't think the risk is high (and we'd want to find and fix any such bugs anyway), and it should be more efficient overall. The new tests in p5600 show off the improvement (this is on git.git): Test HEAD^ HEAD ------------------------------------------------------------------------------- 5600.5: count commits 0.37(0.37+0.00) 0.38(0.38+0.00) +2.7% 5600.6: count non-promisor commits 11.74(11.37+0.37) 0.04(0.03+0.00) -99.7% The improvement is particularly big in this script because _every_ object in the newly-cloned partial repo is a promisor object. So after marking them all, there's nothing left to traverse. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-10revision: mark commit parents as NOT_USER_GIVENLibravatar Patrick Steinhardt1-2/+2
The NOT_USER_GIVEN flag of an object marks whether a flag was explicitly provided by the user or not. The most important use case for this is when filtering objects: only objects that were not explicitly requested will get filtered. The flag is currently only set for blobs and trees, which has been fine given that there are no filters for tags or commits currently. We're about to extend filtering capabilities to add object type filter though, which requires us to set up the NOT_USER_GIVEN flag correctly -- if it's not set, the object wouldn't get filtered at all. Mark unseen commit parents as NOT_USER_GIVEN when processing parents. Like this, explicitly provided parents stay user-given and thus unfiltered, while parents which get loaded as part of the graph walk can be filtered. This commit shouldn't have any user-visible impact yet as there is no logic to filter commits yet. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-24Merge branch 'tb/geometric-repack'Libravatar Junio C Hamano1-0/+15
"git repack" so far has been only capable of repacking everything under the sun into a single pack (or split by size). A cleverer strategy to reduce the cost of repacking a repository has been introduced. * tb/geometric-repack: builtin/pack-objects.c: ignore missing links with --stdin-packs builtin/repack.c: reword comment around pack-objects flags builtin/repack.c: be more conservative with unsigned overflows builtin/repack.c: assign pack split later t7703: test --geometric repack with loose objects builtin/repack.c: do not repack single packs with --geometric builtin/repack.c: add '--geometric' option packfile: add kept-pack cache for find_kept_pack_entry() builtin/pack-objects.c: rewrite honor-pack-keep logic p5303: measure time to repack with keep p5303: add missing &&-chains builtin/pack-objects.c: add '--stdin-packs' option revision: learn '--no-kept-objects' packfile: introduce 'find_kept_pack_entry()'
2021-03-13use CALLOC_ARRAYLibravatar René Scharfe1-3/+3
Add and apply a semantic patch for converting code that open-codes CALLOC_ARRAY to use it instead. It shortens the code and infers the element size automatically. Signed-off-by: René Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-22revision: learn '--no-kept-objects'Libravatar Taylor Blau1-0/+15
A future caller will want to be able to perform a reachability traversal which terminates when visiting an object found in a kept pack. The closest existing option is '--honor-pack-keep', but this isn't quite what we want. Instead of halting the traversal midway through, a full traversal is always performed, and the results are only trimmed afterwords. Besides needing to introduce a new flag (since culling results post-facto can be different than halting the traversal as it's happening), there is an additional wrinkle handling the distinction in-core and on-disk kept packs. That is: what kinds of kept pack should stop the traversal? Introduce '--no-kept-objects[=<on-disk|in-core>]' to specify which kinds of kept packs, if any, should stop a traversal. This can be useful for callers that want to perform a reachability analysis, but want to leave certain packs alone (for e.g., when doing a geometric repack that has some "large" packs which are kept in-core that it wants to leave alone). Note that this option is not guaranteed to produce exactly the set of objects that aren't in kept packs, since it's possible the traversal order may end up in a situation where a non-kept ancestor was "cut off" by a kept object (at which point we would stop traversing). But, we don't care about absolute correctness here, since this will eventually be used as a purely additive guide in an upcoming new repack mode. Explicitly avoid documenting this new flag, since it is only used internally. In theory we could avoid even adding it rev-list, but being able to spell this option out on the command-line makes some special cases easier to test without promising to keep it behaving consistently forever. Those tricky cases are exercised in t6114. Signed-off-by: Taylor Blau <me@ttaylorr.com> Reviewed-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-17Merge branch 'ak/corrected-commit-date'Libravatar Junio C Hamano1-5/+8
The commit-graph learned to use corrected commit dates instead of the generation number to help topological revision traversal. * ak/corrected-commit-date: doc: add corrected commit date info commit-reach: use corrected commit dates in paint_down_to_common() commit-graph: use generation v2 only if entire chain does commit-graph: implement generation data chunk commit-graph: implement corrected commit date commit-graph: return 64-bit generation number commit-graph: add a slab to store topological levels t6600-test-reach: generalize *_three_modes commit-graph: consolidate fill_commit_graph_info revision: parse parent in indegree_walk_step() commit-graph: fix regression when computing Bloom filters
2021-02-10Merge branch 'ab/lose-grep-debug'Libravatar Junio C Hamano1-2/+0
Lose the debugging aid that may have been useful in the past, but no longer is, in the "grep" codepaths. * ab/lose-grep-debug: grep/log: remove hidden --debug and --grep-debug options
2021-02-05Merge branch 'so/log-diff-merge'Libravatar Junio C Hamano1-34/+4
"git log" learned a new "--diff-merges=<how>" option. * so/log-diff-merge: (32 commits) t4013: add tests for --diff-merges=first-parent doc/git-show: include --diff-merges description doc/rev-list-options: document --first-parent changes merges format doc/diff-generate-patch: mention new --diff-merges option doc/git-log: describe new --diff-merges options diff-merges: add '--diff-merges=1' as synonym for 'first-parent' diff-merges: add old mnemonic counterparts to --diff-merges diff-merges: let new options enable diff without -p diff-merges: do not imply -p for new options diff-merges: implement new values for --diff-merges diff-merges: make -m/-c/--cc explicitly mutually exclusive diff-merges: refactor opt settings into separate functions diff-merges: get rid of now empty diff_merges_init_revs() diff-merges: group diff-merge flags next to each other inside 'rev_info' diff-merges: split 'ignore_merges' field diff-merges: fix -m to properly override -c/--cc t4013: add tests for -m failing to override -c/--cc t4013: support test_expect_failure through ':failure' magic diff-merges: revise revs->diff flag handling diff-merges: handle imply -p on -c/--cc logic for log.c ...
2021-01-26grep/log: remove hidden --debug and --grep-debug optionsLibravatar Ævar Arnfjörð Bjarmason1-2/+0
Remove the hidden "grep --debug" and "log --grep-debug" options added in 17bf35a3c7b (grep: teach --debug option to dump the parse tree, 2012-09-13). At the time these options seem to have been intended to go along with a documentation discussion and to help the author of relevant tests to perform ad-hoc debugging on them[1]. Reasons to want this gone: 1. They were never documented, and the only (rather trivial) use of them in our own codebase for testing is something I removed back in e01b4dab01e (grep: change non-ASCII -i test to stop using --debug, 2017-05-20). 2. Googling around doesn't show any in-the-wild uses I could dig up, and on the Git ML the only mentions after the original discussion seem to have been when they came up in unrelated diff contexts, or that test commit of mine. 3. An exception to that is c581e4a7499 (grep: under --debug, show whether PCRE JIT is enabled, 2019-08-18) where we added the ability to dump out when PCREv2 has the JIT in effect. The combination of that and my earlier b65abcafc7a (grep: use PCRE v2 for optimized fixed-string search, 2019-07-01) means Git prints this out in its most common in-the-wild configuration: $ git log --grep-debug --grep=foo --grep=bar --grep=baz --all-match pcre2_jit_on=1 pcre2_jit_on=1 pcre2_jit_on=1 [all-match] (or pattern_body<body>foo (or pattern_body<body>bar pattern_body<body>baz ) ) $ git grep --debug \( -e foo --and -e bar \) --or -e baz pcre2_jit_on=1 pcre2_jit_on=1 pcre2_jit_on=1 (or (and patternfoo patternbar ) patternbaz ) I.e. for each pattern we're considering for the and/or/--all-match etc. debugging we'll now diligently spew out another identical line saying whether the PCREv2 JIT is on or not. I think that nobody's complained about that rather glaringly obviously bad output says something about how much this is used, i.e. it's not. The need for this debugging aid for the composed grep/log patterns seems to have passed, and the desire to dump the JIT config seems to have been another one-off around the time we had JIT-related issues on the PCREv2 codepath. That the original author of this debugging facility seemingly hasn't noticed the bad output since then[2] is probably some indicator. 1. https://lore.kernel.org/git/cover.1347615361.git.git@drmicha.warpmail.net/ 2. https://lore.kernel.org/git/xmqqk1b8x0ac.fsf@gitster-ct.c.googlers.com/ Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-25Merge branch 'jk/log-cherry-pick-duplicate-patches'Libravatar Junio C Hamano1-2/+4
When more than one commit with the same patch ID appears on one side, "git log --cherry-pick A...B" did not exclude them all when a commit with the same patch ID appears on the other side. Now it does. * jk/log-cherry-pick-duplicate-patches: patch-ids: handle duplicate hashmap entries
2021-01-18commit-graph: return 64-bit generation numberLibravatar Abhishek Kumar1-5/+5
In a preparatory step for introducing corrected commit dates, let's return timestamp_t values from commit_graph_generation(), use timestamp_t for local variables and define GENERATION_NUMBER_INFINITY as (2 ^ 63 - 1) instead. We rename GENERATION_NUMBER_MAX to GENERATION_NUMBER_V1_MAX to represent the largest topological level we can store in the commit data chunk. With corrected commit dates implemented, we will have two such *_MAX variables to denote the largest offset and largest topological level that can be stored. Signed-off-by: Abhishek Kumar <abhishekkumar8222@gmail.com> Reviewed-by: Taylor Blau <me@ttaylorr.com> Reviewed-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-18revision: parse parent in indegree_walk_step()Libravatar Abhishek Kumar1-0/+3
In indegree_walk_step(), we add unvisited parents to the indegree queue. However, parents are not guaranteed to be parsed. As the indegree queue sorts by generation number, let's parse parents before inserting them to ensure the correct priority order. Signed-off-by: Abhishek Kumar <abhishekkumar8222@gmail.com> Reviewed-by: Taylor Blau <me@ttaylorr.com> Reviewed-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-12patch-ids: handle duplicate hashmap entriesLibravatar Jeff King1-2/+4
This fixes a bug introduced in dfb7a1b4d0 (patch-ids: stop using a hand-rolled hashmap implementation, 2016-07-29) in which git rev-list --cherry-pick A...B will fail to suppress commits reachable from A even if a commit with matching patch-id appears in B. Around the time of that commit, the algorithm for "--cherry-pick" looked something like this: 0. Traverse all of the commits, marking them as being on the left or right side of the symmetric difference. 1. Iterate over the left-hand commits, inserting a patch-id struct for each into a hashmap, and pointing commit->util to the patch-id struct. 2. Iterate over the right-hand commits, checking which are present in the hashmap. If so, we exclude the commit from the output _and_ we mark the patch-id as "seen". 3. Iterate again over the left-hand commits, checking whether commit->util->seen is set; if so, exclude them from the output. At the end, we'll have eliminated commits from both sides that have a matching patch-id on the other side. But there's a subtle assumption here: for any given patch-id, we must have exactly one struct representing it. If two commits from A both have the same patch-id and we allow duplicates in the hashmap, then we run into a problem: a. In step 1, we insert two patch-id structs into the hashmap. b. In step 2, our lookups will find only one of these structs, so only one "seen" flag is marked. c. In step 3, one of the commits in A will have its commit->util->seen set, but the other will not. We'll erroneously output the latter. Prior to dfb7a1b4d0, our hashmap did not allow duplicates. Afterwards, it used hashmap_add(), which explicitly does allow duplicates. At that point, the solution would have been easy: when we are about to add a duplicate, skip doing so and return the existing entry which matches. But it gets more complicated. In 683f17ec44 (patch-ids: replace the seen indicator with a commit pointer, 2016-07-29), our step 3 goes away entirely. Instead, in step 2, when the right-hand side finds a matching patch_id from the left-hand side, we can directly mark the left-hand patch_id->commit to be omitted. Solving that would be easy, too; there's a one-to-many relationship of patch-ids to commits, so we just need to keep a list. But there's more. Commit b3dfeebb92 (rebase: avoid computing unnecessary patch IDs, 2016-07-29) built on that by lazily computing the full patch-ids. So we don't even know when adding to the hashmap whether two commits truly have the same id. We'd have to tentatively assign them a list, and then possibly split them apart (possibly into N new structs) at the moment we compute the real patch-ids. This could work, but it's complicated and error-prone. Instead, let's accept that we may store duplicates, and teach the lookup side to be more clever. Rather than asking for a single matching patch-id, it will need to iterate over all matching patch-ids. This does mean examining every entry in a single hash bucket, but the worst-case for a hash lookup was already doing that. We'll keep the hashmap details out of the caller by providing a simple iteration interface. We can retain the simple has_commit_patch_id() interface for the other callers, but we'll simplify its return value into an integer, rather than returning the patch_id struct. That way they won't be tempted to look at the "commit" field of the return value without iterating. Reported-by: Arnaud Morin <arnaud.morin@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-04revision: trace topo-walk statisticsLibravatar Derrick Stolee1-0/+31
We trace statistics about the effectiveness of changed-path Bloom filters since 42e50e78 (revision.c: add trace2 stats around Bloom filter usage, 2020-04-06). Add similar tracing for the topo-walk algorithm that uses generation numbers to limit the walk size. This information can help investigate and describe benefits to heuristics and other changes. The information that is printed is in JSON format and can be formatted nicely to present as follows: { "count_explort_walked":2603, "count_indegree_walked":2603, "count_topo_walked":473 } Each of these values count the number of commits are visited by each of the three "stages" of the topo-walk as detailed in b4542418 (revision.c: generation-based topo-order algorithm, 2018-11-01). Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-21diff-merges: get rid of now empty diff_merges_init_revs()Libravatar Sergey Organov1-1/+0
After getting rid of 'ignore_merges' field, the diff_merges_init_revs() function became empty. Get rid of it. Signed-off-by: Sergey Organov <sorganov@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-21diff-merges: rename all functions to have common prefixLibravatar Sergey Organov1-3/+3
Use the same "diff_merges" prefix for all the diff merges function names. Signed-off-by: Sergey Organov <sorganov@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-21revision: move diff merges functions to its own diff-merges.cLibravatar Sergey Organov1-75/+1
Create separate diff-merges.c and diff-merges.h files, and move all the code related to handling of diff merges there. Signed-off-by: Sergey Organov <sorganov@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-21revision: provide implementation for diff merges tweaksLibravatar Sergey Organov1-0/+19
Use these implementations from show_setup_revisions_tweak() and log_setup_revisions_tweak() in builtin/log.c. This completes moving of management of diff merges parameters to a single place, where we can finally observe them simultaneously. Signed-off-by: Sergey Organov <sorganov@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-21revision: factor out initialization of diff-merge related settingsLibravatar Sergey Organov1-1/+8
Move initialization code related to diffing merges into new init_diff_merge_revs() function. Signed-off-by: Sergey Organov <sorganov@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-21revision: factor out setup of diff-merge related settingsLibravatar Sergey Organov1-6/+12
Move all the setting code related to diffing merges into new setup_diff_merge_revs() function. Signed-off-by: Sergey Organov <sorganov@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-21revision: factor out parsing of diff-merge related optionsLibravatar Sergey Organov1-27/+40
Move all the parsing code related to diffing merges into new parse_diff_merge_opts() function. Signed-off-by: Sergey Organov <sorganov@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-08Merge branch 'ma/grep-init-default'Libravatar Junio C Hamano1-1/+0
Code clean-up. * ma/grep-init-default: MyFirstObjectWalk: drop `init_walken_defaults()` grep: copy struct in one fell swoop grep: use designated initializers for `grep_defaults` grep: don't set up a "default" repo for grep
2020-11-21grep: use designated initializers for `grep_defaults`Libravatar Martin Ågren1-1/+0
In 15fabd1bbd ("builtin/grep.c: make configuration callback more reusable", 2012-10-09), we learned to fill a `static struct grep_opt grep_defaults` which we can use as a blueprint for other such structs. At the time, we didn't consider designated initializers to be widely useable, but these days, we do. (See, e.g., cbc0f81d96 ("strbuf: use designated initializers in STRBUF_INIT", 2017-07-10).) Use designated initializers to let the compiler set up the struct and so that we don't need to remember to call `init_grep_defaults()`. Signed-off-by: Martin Ågren <martin.agren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-21grep: don't set up a "default" repo for grepLibravatar Martin Ågren1-1/+1
`init_grep_defaults()` fills a `static struct grep_opt grep_defaults`. This struct is then used by `grep_init()` as a blueprint for other such structs. Notably, `grep_init()` takes a `struct repo *` and assigns it into the target struct. As a result, it is unnecessary for us to take a `struct repo *` in `init_grep_defaults()` as well. We assign it into the default struct and never look at it again. And in light of how we return early if we have already set up the default struct, it's not just unnecessary, but is also a bit confusing: If we are called twice and with different repos, is it a bug or a feature that we ignore the second repo? Drop the repo parameter for `init_grep_defaults()`. Signed-off-by: Martin Ågren <martin.agren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-11Use new HASHMAP_INIT macro to simplify hashmap initializationLibravatar Elijah Newren1-8/+1
Now that hashamp has lazy initialization and a HASHMAP_INIT macro, hashmaps allocated on the stack can be initialized without a call to hashmap_init() and in some cases makes the code a bit shorter. Convert some callsites over to take advantage of this. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-02hashmap: provide deallocation function namesLibravatar Elijah Newren1-1/+1
hashmap_free(), hashmap_free_entries(), and hashmap_free_() have existed for a while, but aren't necessarily the clearest names, especially with hashmap_partial_clear() being added to the mix and lazy-initialization now being supported. Peff suggested we adopt the following names[1]: - hashmap_clear() - remove all entries and de-allocate any hashmap-specific data, but be ready for reuse - hashmap_clear_and_free() - ditto, but free the entries themselves - hashmap_partial_clear() - remove all entries but don't deallocate table - hashmap_partial_clear_and_free() - ditto, but free the entries This patch provides the new names and converts all existing callers over to the new naming scheme. [1] https://lore.kernel.org/git/20201030125059.GA3277724@coredump.intra.peff.net/ Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-30drop unused argc parametersLibravatar Jeff King1-3/+3
Many functions take an argv/argc pair, but never actually look at argc. This makes it useless at best (we use the NULL sentinel in argv to find the end of the array), and misleading at worst (what happens if the argc count does not match the argv NULL?). In each of these instances, the argv NULL does match the argc count, so there are no bugs here. But let's tighten the interfaces to make it harder to get wrong (and to reduce some -Wunused-parameter complaints). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-29Merge branch 'tb/bloom-improvements'Libravatar Junio C Hamano1-5/+2
"git commit-graph write" learned to limit the number of bloom filters that are computed from scratch with the --max-new-filters option. * tb/bloom-improvements: commit-graph: introduce 'commitGraph.maxNewFilters' builtin/commit-graph.c: introduce '--max-new-filters=<n>' commit-graph: rename 'split_commit_graph_opts' bloom: encode out-of-bounds filters as non-empty bloom/diff: properly short-circuit on max_changes bloom: use provided 'struct bloom_filter_settings' bloom: split 'get_bloom_filter()' in two commit-graph.c: store maximum changed paths commit-graph: respect 'commitGraph.readChangedPaths' t/helper/test-read-graph.c: prepare repo settings commit-graph: pass a 'struct repository *' in more places t4216: use an '&&'-chain commit-graph: introduce 'get_bloom_filter_settings()'
2020-09-18Merge branch 'mf/submodule-summary-with-correct-repository'Libravatar Junio C Hamano1-9/+9
"git diff/show" on a change that involves a submodule used to read the information on commits in the submodule from a wrong repository and gave a wrong information when the commit-graph is involved. * mf/submodule-summary-with-correct-repository: submodule: use submodule repository when preparing summary revision: use repository from rev_info when parsing commits
2020-09-17bloom: split 'get_bloom_filter()' in twoLibravatar Taylor Blau1-1/+1
'get_bloom_filter' takes a flag to control whether it will compute a Bloom filter if the requested one is missing. In the next patch, we'll add yet another parameter to this method, which would force all but one caller to specify an extra 'NULL' parameter at the end. Instead of doing this, split 'get_bloom_filter' into two functions: 'get_bloom_filter' and 'get_or_compute_bloom_filter'. The former only looks up a Bloom filter (and does not compute one if it's missing, thus dropping the 'compute_if_not_present' flag). The latter does compute missing Bloom filters, with an additional parameter to store whether or not it needed to do so. This simplifies many call-sites, since the majority of existing callers to 'get_bloom_filter' do not want missing Bloom filters to be computed (so they can drop the parameter entirely and use the simpler version of the function). While we're at it, instrument the new 'get_or_compute_bloom_filter()' with counters in the 'write_commit_graph_context' struct which store the number of filters that we did and didn't compute, as well as filters that were truncated. It would be nice to drop the 'compute_if_not_present' flag entirely, since all remaining callers of 'get_or_compute_bloom_filter' pass it as '1', but this will change in a future patch and hence cannot be removed. Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-09Merge branch 'jt/interpret-branch-name-fallback'Libravatar Junio C Hamano1-1/+2
"git status" has trouble showing where it came from by interpreting reflog entries that recordcertain events, e.g. "checkout @{u}", and gives a hard/fatal error. Even though it inherently is impossible to give a correct answer because the reflog entries lose some information (e.g. "@{u}" does not record what branch the user was on hence which branch 'the upstream' needs to be computed, and even if the record were available, the relationship between branches may have changed), at least hide the error to allow "status" show its output. * jt/interpret-branch-name-fallback: wt-status: tolerate dangling marks refs: move dwim_ref() to header file sha1-name: replace unsigned int with option struct
2020-09-09Merge branch 'so/separate-field-for-m-and-diff-merges'Libravatar Junio C Hamano1-0/+6
Internal API clean-up to handle two options "diff-index" and "log" have, which happen to share the same short form, more sensibly. * so/separate-field-for-m-and-diff-merges: revision: add separate field for "-m" of "diff-index -m"
2020-09-09commit-graph: introduce 'get_bloom_filter_settings()'Libravatar Taylor Blau1-4/+1
Many places in the code often need a pointer to the commit-graph's 'struct bloom_filter_settings', in which case they often take the value from the top-most commit-graph. In the non-split case, this works as expected. In the split case, however, things get a little tricky. Not all layers in a chain of incremental commit-graphs are required to themselves have Bloom data, and so whether or not some part of the code uses Bloom filters depends entirely on whether or not the top-most level of the commit-graph chain has Bloom filters. This has been the behavior since Bloom filters were introduced, and has been codified into the tests since a759bfa9ee (t4216: add end to end tests for git log with Bloom filters, 2020-04-06). In fact, t4216.130 requires that Bloom filters are not used in exactly the case described earlier. There is no reason that this needs to be the case, since it is perfectly valid for commits in an earlier layer to have Bloom filters when commits in a newer layer do not. Since Bloom settings are guaranteed in practice to be the same for any layer in a chain that has Bloom data, it is sufficient to traverse the '->base_graph' pointer until either (1) a non-null 'struct bloom_filter_settings *' is found, or (2) until we are at the root of the commit-graph chain. Introduce a 'get_bloom_filter_settings()' function that does just this, and use it instead of purely dereferencing the top-most graph's '->bloom_filter_settings' pointer. While we're at it, add an additional test in t5324 to guard against code in the commit-graph writing machinery that doesn't correctly handle a NULL 'struct bloom_filter *'. Co-authored-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-02sha1-name: replace unsigned int with option structLibravatar Jonathan Tan1-1/+2
In preparation for a future patch adding a boolean parameter to repo_interpret_branch_name(), which might be easily confused with an existing unsigned int parameter, refactor repo_interpret_branch_name() to take an option struct instead of the unsigned int parameter. The static function interpret_branch_mark() is also updated to take the option struct in preparation for that future patch, since it will also make use of the to-be-introduced boolean parameter. Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-31Merge branch 'jk/rev-input-given-fix'Libravatar Junio C Hamano1-5/+11
Feeding "$ZERO_OID" to "git log --ignore-missing --stdin", and running "git log --ignore-missing $ZERO_OID" fell back to start digging from HEAD; it has been corrected to become a no-op, like "git log --tags=no-tag-matches-this-pattern" does. * jk/rev-input-given-fix: revision: set rev_input_given in handle_revision_arg()
2020-08-31revision: add separate field for "-m" of "diff-index -m"Libravatar Sergey Organov1-0/+6
Add separate 'match_missing' field for diff-index to use and set it when we encounter "-m" option. This field won't then be cleared when another meaning of "-m" is reverted (e.g., by "--no-diff-merges"), nor it will be affected by future option(s) that might drive 'ignore_merges' field. Use this new field from diff-lib:do_oneway_diff() instead of reusing 'ignore_merges' field. Signed-off-by: Sergey Organov <sorganov@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-26revision: set rev_input_given in handle_revision_arg()Libravatar Jeff King1-5/+11
Commit 7ba826290a (revision: add rev_input_given flag, 2017-08-02) added a flag to rev_info to tell whether we got any revision arguments. As explained there, this is necessary because some revision arguments may not produce any pending traversal objects, but should still inhibit default behaviors (e.g., a glob that matches nothing). However, it only set the flag in the globbing code, but not for revisions we get on the command-line or via stdin. This leads to two problems: - the command-line code keeps its own separate got_rev_arg flag; this isn't wrong, but it's confusing and an extra maintenance burden - even specifically-named rev arguments might end up not adding any pending objects: if --ignore-missing is set, then specifying a missing object is a noop rather than an error. And that leads to some user-visible bugs: - when deciding whether a default rev like "HEAD" should kick in, we check both got_rev_arg and rev_input_given. That means that "--ignore-missing $ZERO_OID" works on the command-line (where we set got_rev_arg) but not on --stdin (where we don't) - when rev-list decides whether it should complain that it wasn't given a starting point, it relies on rev_input_given. So it can't even get the command-line "--ignore-missing $ZERO_OID" right Let's consistently set the flag if we got any revision argument. That lets us clean up the redundant got_rev_arg, and fixes both of those bugs (but note there are three new tests: we'll confirm the already working git-log command-line case). A few implementation notes: - conceptually we want to set the flag whenever handle_revision_arg() finds an actual revision arg ("handles" it, you might say). But it covers a ton of cases with early returns. Rather than annotating each one, we just wrap it and use its success exit-code to set the flag in one spot. - the new rev-list test is in t6018, which is titled to cover globs. This isn't exactly a glob, but it made sense to stick it with the other tests that handle the "even though we got a rev, we have no pending objects" case, which are globs. - the tests check for the oid of a missing object, which it's pretty clear --ignore-missing should ignore. You can see the same behavior with "--ignore-missing a-ref-that-does-not-exist", because --ignore-missing treats them both the same. That's perhaps less clearly correct, and we may want to change that in the future. But the way the code and tests here are written, we'd continue to do the right thing even if it does. Reported-by: Bryan Turner <bturner@atlassian.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-17Merge branch 'so/log-diff-merges-opt'Libravatar Junio C Hamano1-1/+8
Earlier, to countermand the implicit "-m" option when the "--first-parent" option is used with "git log", we added the "--[no-]diff-merges" option in the jk/log-fp-implies-m topic. To leave the door open to allow the "--diff-merges" option to take values that instructs how patches for merge commits should be computed (e.g. "cc"? "-p against first parent?"), redefine "--diff-merges" to take non-optional value, and implement "off" that means the same thing as "--no-diff-merges". * so/log-diff-merges-opt: t/t4013: add test for --diff-merges=off doc/git-log: describe --diff-merges=off revision: change "--diff-merges" option to require parameter
2020-08-17Merge branch 'jk/log-fp-implies-m'Libravatar Junio C Hamano1-3/+7
"git log --first-parent -p" showed patches only for single-parent commits on the first-parent chain; the "--first-parent" option has been made to imply "-m". Use "--no-diff-merges" to restore the previous behaviour to omit patches for merge commits. * jk/log-fp-implies-m: doc/git-log: clarify handling of merge commit diffs doc/git-log: move "-t" into diff-options list doc/git-log: drop "-r" diff option doc/git-log: move "Diff Formatting" from rev-list-options log: enable "-m" automatically with "--first-parent" revision: add "--no-diff-merges" option to counteract "-m" log: drop "--cc implies -m" logic
2020-08-17Merge branch 'al/bisect-first-parent'Libravatar Junio C Hamano1-3/+0
"git bisect" learns the "--first-parent" option to find the first breakage along the first-parent chain. * al/bisect-first-parent: bisect: combine args passed to find_bisection() bisect: introduce first-parent flag cmd_bisect__helper: defer parsing no-checkout flag rev-list: allow bisect and first-parent flags t6030: modernize "git bisect run" tests