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2022-03-16Merge branch 'ab/string-list-count-in-size-t'Libravatar Junio C Hamano1-3/+3
Count string_list items in size_t, not "unsigned int". * ab/string-list-count-in-size-t: string-list API: change "nr" and "alloc" to "size_t" gettext API users: don't explicitly cast ngettext()'s "n"
2022-03-16Merge branch 'ds/commit-graph-gen-v2-fixes'Libravatar Junio C Hamano1-6/+13
Fixes to the way generation number v2 in the commit-graph files are (not) handled. * ds/commit-graph-gen-v2-fixes: commit-graph: declare bankruptcy on GDAT chunks commit-graph: fix generation number v2 overflow values commit-graph: start parsing generation v2 (again) commit-graph: fix ordering bug in generation numbers t5318: extract helpers to lib-commit-graph.sh test-read-graph: include extra post-parse info
2022-03-07string-list API: change "nr" and "alloc" to "size_t"Libravatar Ævar Arnfjörð Bjarmason1-3/+3
Change the "nr" and "alloc" members of "struct string_list" to use "size_t" instead of "nr". On some platforms the size of an "unsigned int" will be smaller than a "size_t", e.g. a 32 bit unsigned v.s. 64 bit unsigned. As "struct string_list" is a generic API we use in a lot of places this might cause overflows. As one example: code in "refs.c" keeps track of the number of refs with a "size_t", and auxiliary code in builtin/remote.c in get_ref_states() appends those to a "struct string_list". While we're at it split the "nr" and "alloc" in string-list.h across two lines, which is the case for most such struct member declarations (e.g. in "strbuf.h" and "strvec.h"). Changing e.g. "int i" to "size_t i" in run_and_feed_hook() isn't strictly necessary, and there are a lot more cases where we'll use a local "int", "unsigned int" etc. variable derived from the "nr" in the "struct string_list". But in that case as well as add_wrapped_shortlog_msg() in builtin/shortlog.c we need to adjust the printf format referring to "nr" anyway, so let's also change the other variables referring to it. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-07commit-graph: declare bankruptcy on GDAT chunksLibravatar Derrick Stolee1-2/+2
The Generation Data (GDAT) and Generation Data Overflow (GDOV) chunks store corrected commit date offsets, used for generation number v2. Recent changes have demonstrated that previous versions of Git were incorrectly parsing data from these chunks, but might have also been writing them incorrectly. I asserted [1] that the previous fixes were sufficient because the known reasons for incorrectly writing generation number v2 data relied on parsing the information incorrectly out of a commit-graph file, but the previous versions of Git were not reading the generation number v2 data. However, Patrick demonstrated [2] a case where in split commit-graphs across an alternate boundary (and possibly some other special conditions) it was possible to have a commit-graph that was generated by a previous version of Git have incorrect generation number v2 data which results in errors like the following: commit-graph generation for commit <oid> is 1623273624 < 1623273710 [1] https://lore.kernel.org/git/f50e74f0-9ffa-f4f2-4663-269801495ed3@github.com/ [2] https://lore.kernel.org/git/Yh93vOkt2DkrGPh2@ncase/ Clearly, there is something else going on. The situation is not completely understood, but the errors do not reproduce if the commit-graphs are all generated by a Git version including these recent fixes. If we cannot trust the existing data in the GDAT and GDOV chunks, then we can alter the format to change the chunk IDs for these chunks. This causes the new version of Git to silently ignore the older chunks (and disabling generation number v2 in the process) while writing new commit-graph files with correct data in the GDA2 and GDO2 chunks. Update commit-graph-format.txt including a historical note about these deprecated chunks. Reported-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-04lockfile API users: simplify and don't leak "path"Libravatar Ævar Arnfjörð Bjarmason1-0/+2
Fix a memory leak in code added in 6c622f9f0bb (commit-graph: write commit-graph chains, 2019-06-18). We needed to free the "lock_name" if we encounter errors, and the "graph_name" after we'd run unlink() on it. For the case of write_commit_graph_file() refactoring the code to free the "lock_name" after we were done using the "struct lock_file lk" would have made the control flow more complex. Luckily we can free the "lock_file" right after the hold_lock_file_for_update() call, if it makes use of "path" at all it'll have copied its contents to a "struct strbuf" of its own. While I'm at it let's fix code added in fb10ca5b543 (sparse-checkout: write using lockfile, 2019-11-21) in write_patterns_and_update() to avoid the same complexity that I thought I needed when I wrote the initial fix for write_commit_graph_file(). We can free the "sparse_filename" right after calling hold_lock_file_for_update(), we don't need to wait until we're exiting the function to do so. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-04commit-graph: stop fill_oids_from_packs() progress on error and free()Libravatar Ævar Arnfjörð Bjarmason1-5/+7
Fix a bug in fill_oids_from_packs(), we should always stop_progress(), but did not do so if we returned an error here. This also plugs a memory leak in those cases by releasing the two "struct strbuf" variables the function uses. While I'm at it stop hardcoding "-1" here and just use the return value of error() instead, which happens to be "-1". Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-04commit-graph: fix memory leak in misused string_list APILibravatar Ævar Arnfjörð Bjarmason1-2/+2
When this code was migrated to the string_list API in d88b14b3fd6 (commit-graph: use string-list API for input, 2018-06-27) it was made to use used both STRING_LIST_INIT_NODUP and a strbuf_detach() pattern. Those should not be used together if string_list_clear() is expected to free the memory, instead we need to either use STRING_LIST_INIT_DUP with a string_list_append_nodup(), or a STRING_LIST_INIT_NODUP and manually fiddle with the "strdup_strings" member before calling string_list_clear(). Let's do the former. Since "strdup_strings = 1" is set now other code might be broken by relying on "pack_indexes" not to duplicate it strings, but that doesn't happen. When we pass this down to write_commit_graph() that code uses the "struct string_list" without modifying it. Let's add a "const" to the variable to have the compiler enforce that assumption. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-01commit-graph: fix generation number v2 overflow valuesLibravatar Derrick Stolee1-1/+1
The Generation Data Chunk was implemented and tested in e8b63005c (commit-graph: implement generation data chunk, 2021-01-16), but the test was carefully constructed to work on systems with 32-bit dates. Since the corrected commit date offsets still required more than 31 bits, this triggered writing the generation_data_overflow chunk. However, upon closer look, the write_graph_chunk_generation_data_overflow() method writes the offsets to the chunk (as dictated by the format) but fill_commit_graph_info() treats the value in the chunk as if it is the full corrected commit date (not an offset). For some reason, this does not cause an issue when using the FUTURE_DATE specified in t5318-commit-graph.sh, but it does show up as a failure in 'git commit-graph verify' if we increase that FUTURE_DATE to be above four billion. Fix this error and create a 64-bit timestamp version of the test so we can test these larger values. Signed-off-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-01commit-graph: start parsing generation v2 (again)Libravatar Derrick Stolee1-0/+3
The 'read_generation_data' member of 'struct commit_graph' was introduced by 1fdc383c5 (commit-graph: use generation v2 only if entire chain does, 2021-01-16). The intention was to avoid using corrected commit dates if not all layers of a commit-graph had that data stored. The logic in validate_mixed_generation_chain() at that point incorrectly initialized read_generation_data to 1 if and only if the tip commit-graph contained the Corrected Commit Date chunk. This was "fixed" in 448a39e65 (commit-graph: validate layers for generation data, 2021-02-02) to validate that read_generation_data was either non-zero for all layers, or it would set read_generation_data to zero for all layers. The problem here is that read_generation_data is not initialized to be non-zero anywhere! This change initializes read_generation_data immediately after the chunk is parsed, so each layer will have its value present as soon as possible. The read_generation_data member is used in fill_commit_graph_info() to determine if we should use the corrected commit date or the topological levels stored in the Commit Data chunk. Due to this bug, all previous versions of Git were defaulting to topological levels in all cases! This can be measured with some performance tests. Using the Linux kernel as a testbed, I generated a complete commit-graph containing corrected commit dates and tested the 'new' version against the previous, 'old' version. First, rev-list with --topo-order demonstrates a 26% improvement using corrected commit dates: hyperfine \ -n "old" "$OLD_GIT rev-list --topo-order -1000 v3.6" \ -n "new" "$NEW_GIT rev-list --topo-order -1000 v3.6" \ --warmup=10 Benchmark 1: old Time (mean ± σ): 57.1 ms ± 3.1 ms Range (min … max): 52.9 ms … 62.0 ms 55 runs Benchmark 2: new Time (mean ± σ): 45.5 ms ± 3.3 ms Range (min … max): 39.9 ms … 51.7 ms 59 runs Summary 'new' ran 1.26 ± 0.11 times faster than 'old' These performance improvements are due to the algorithmic improvements given by walking fewer commits due to the higher cutoffs from corrected commit dates. However, this comes at a cost. The additional I/O cost of parsing the corrected commit dates is visible in case of merge-base commands that do not reduce the overall number of walked commits. hyperfine \ -n "old" "$OLD_GIT merge-base v4.8 v4.9" \ -n "new" "$NEW_GIT merge-base v4.8 v4.9" \ --warmup=10 Benchmark 1: old Time (mean ± σ): 110.4 ms ± 6.4 ms Range (min … max): 96.0 ms … 118.3 ms 25 runs Benchmark 2: new Time (mean ± σ): 150.7 ms ± 1.1 ms Range (min … max): 149.3 ms … 153.4 ms 19 runs Summary 'old' ran 1.36 ± 0.08 times faster than 'new' Performance issues like this are what motivated 702110aac (commit-graph: use config to specify generation type, 2021-02-25). In the future, we could fix this performance problem by inserting the corrected commit date offsets into the Commit Date chunk instead of having that data in an extra chunk. Signed-off-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-01commit-graph: fix ordering bug in generation numbersLibravatar Derrick Stolee1-3/+7
When computing the generation numbers for a commit-graph, we compute the corrected commit dates and then check if their offsets from the actual dates is too large to fit in the 32-bit Generation Data chunk. However, there is a problem with this approach: if we have parsed the generation data from the previous commit-graph, then we continue the loop because the corrected commit date is already computed. This causes an under-count in the number of overflow values. It is incorrect to add an increment to num_generation_data_overflows next to this 'continue' statement, because we might start double-counting commits that are computed because of the depth-first search walk from a commit with an earlier OID. Instead, iterate over the full commit list at the end, checking the offsets to see how many grow beyond the maximum value. Create a new t5328-commit-graph-64-bit-time.sh test script to handle special cases of testing 64-bit timestamps. This helps demonstrate this bug in more cases. It still won't hit all potential cases until the next change, which reenables reading generation numbers. Use the skip_all trick from 0a2bfccb9c8 (t0051: use "skip_all" under !MINGW in single-test file, 2022-02-04) to make the output clean when run on a 32-bit system. Helped-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-06commit-graph: return if there is no git directoryLibravatar Lessley Dennington1-1/+4
Return early if git directory does not exist. This will protect against test failures in the upcoming change to BUG in prepare_repo_settings if no git directory exists. Signed-off-by: Lessley Dennington <lessleydennington@gmail.com> Reviewed-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-20Merge branch 'js/run-command-close-packs'Libravatar Junio C Hamano1-0/+1
The run-command API has been updated so that the callers can easily ask the file descriptors open for packfiles to be closed immediately before spawning commands that may trigger auto-gc. * js/run-command-close-packs: Close object store closer to spawning child processes run_auto_maintenance(): implicitly close the object store run-command: offer to close the object store before running run-command: prettify the `RUN_COMMAND_*` flags pull: release packs before fetching commit-graph: when closing the graph, also release the slab
2021-09-20Merge branch 'ab/progress-users-adjust-counters'Libravatar Junio C Hamano1-1/+1
The code to show progress indicator in a few code paths did not cover between 0-100%, which has been corrected. * ab/progress-users-adjust-counters: entry: show finer-grained counter in "Filtering content" progress line commit-graph: fix bogus counter in "Scanning merged commits" progress line
2021-09-09commit-graph: fix bogus counter in "Scanning merged commits" progress lineLibravatar SZEDER Gábor1-1/+1
The final value of the counter of the "Scanning merged commits" progress line is always one less than its expected total, e.g.: Scanning merged commits: 83% (5/6), done. This happens because while iterating over an array the loop variable is passed to display_progress() as-is, but while C arrays (and thus the loop variable) start at 0 and end at N-1, the progress counter must end at N. Fix this by passing 'i + 1' to display_progress(), like most other callsites do. There's an RFC series to add a GIT_TEST_CHECK_PROGRESS=1 mode[1] which catches this issue in the 'fetch.writeCommitGraph' and 'fetch.writeCommitGraph with submodules' tests in 't5510-fetch.sh'. The GIT_TEST_CHECK_PROGRESS=1 mode is not part of this series, but future changes to progress.c may add it or similar assertions to catch this and similar bugs elsewhere. 1. https://lore.kernel.org/git/20210620200303.2328957-1-szeder.dev@gmail.com/ Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com> Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-08commit-graph: when closing the graph, also release the slabLibravatar Johannes Schindelin1-0/+1
The slab has information about the commit graph. That means that it is meaningless (and even misleading) when the commit graph was closed. This seems not to matter currently, but we're about to fix a Windows-specific bug where `git pull` does not close the object store before fetching (risking that an implicit auto-gc fails to remove the now-obsolete pack file(s)), and once we have that bug fix in place, it does matter: after that bug fix, we will open the object store, do some stuff with it, then close it, fetch, and then open it again, and do more stuff. If we close the commit graph without releasing the corresponding slab, we're hit by a symptom like this in t5520.19: BUG: commit-reach.c:85: bad generation skip 9223372036854775807 > 3 at 5cd378271655d43a3b4477520014f02213ad1546 Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-08-09revision: avoid hitting packfiles when commits are in commit-graphLibravatar Patrick Steinhardt1-0/+24
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>
2021-08-09commit-graph: split out function to search commit positionLibravatar Patrick Steinhardt1-25/+30
The function `find_commit_in_graph()` assumes that the caller has passed an object which was already determined to be a commit given that it will access the commit's graph position, which is stored in a commit slab. In a subsequent patch, we want to search for an object ID though without knowing whether it is a commit or not, which is not currently possible. Split out the logic to search the commit graph for a given object ID to prepare for this change. This commit also renames the function to `find_commit_pos_in_graph()`, which more accurately reflects what this function does. Furthermore, in order to allow for the searched object ID to be const, we need to adjust `bsearch_graph()`'s signature to accept a constant object ID as input, too. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-28Merge branch 'ab/attribute-format'Libravatar Junio C Hamano1-0/+1
Many "printf"-like helper functions we have have been annotated with __attribute__() to catch placeholder/parameter mismatches. * ab/attribute-format: advice.h: add missing __attribute__((format)) & fix usage *.h: add a few missing __attribute__((format)) *.c static functions: add missing __attribute__((format)) sequencer.c: move static function to avoid forward decl *.c static functions: don't forward-declare __attribute__
2021-07-13*.c static functions: add missing __attribute__((format))Libravatar Ævar Arnfjörð Bjarmason1-0/+1
Add missing __attribute__((format)) function attributes to various "static" functions that take printf arguments. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-06-28commit-graph: rewrite to use checksum_valid()Libravatar Taylor Blau1-8/+6
Rewrite an existing caller in `git commit-graph verify` to take advantage of checksum_valid(). Note that the replacement isn't a verbatim cut-and-paste, since the new function avoids using hashfile at all and instead talks to the_hash_algo directly, but it is functionally equivalent. Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-27commit-graph: don't store file hashes as struct object_idLibravatar brian m. carlson1-6/+7
The idea behind struct object_id is that it is supposed to represent the identifier of a standard Git object or a special pseudo-object like the all-zeros object ID. In this case, we have file hashes, which, while similar, are distinct from the identifiers of objects. Switch these code paths to use an unsigned char array. This is both more logically consistent and it means that we need not set the algorithm identifier for the struct object_id. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-27Always use oidread to read into struct object_idLibravatar brian m. carlson1-6/+6
In the future, we'll want oidread to automatically set the hash algorithm member for an object ID we read into it, so ensure we use oidread instead of hashcpy everywhere we're copying a hash value into a struct object_id. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-22Merge branch 'ds/commit-graph-generation-config'Libravatar Junio C Hamano1-11/+20
A new configuration variable has been introduced to allow choosing which version of the generation number gets used in the commit-graph file. * ds/commit-graph-generation-config: commit-graph: use config to specify generation type commit-graph: create local repository pointer
2021-03-13use CALLOC_ARRAYLibravatar René Scharfe1-2/+2
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>
2021-03-01Merge branch 'ds/chunked-file-api'Libravatar Junio C Hamano1-200/+112
The common code to deal with "chunked file format" that is shared by the multi-pack-index and commit-graph files have been factored out, to help codepaths for both filetypes to become more robust. * ds/chunked-file-api: commit-graph.c: display correct number of chunks when writing chunk-format: add technical docs chunk-format: restore duplicate chunk checks midx: use 64-bit multiplication for chunk sizes midx: use chunk-format read API commit-graph: use chunk-format read API chunk-format: create read chunk API midx: use chunk-format API in write_midx_internal() midx: drop chunk progress during write midx: return success/failure in chunk write methods midx: add num_large_offsets to write_midx_context midx: add pack_perm to write_midx_context midx: add entries to write_midx_context midx: use context in write_midx_pack_names() midx: rename pack_info to write_midx_context commit-graph: use chunk-format write API chunk-format: create chunk format write API commit-graph: anonymize data in chunk_write_fn
2021-03-01Merge branch 'js/commit-graph-warning'Libravatar Junio C Hamano1-11/+3
* js/commit-graph-warning: Revert "commit-graph: when incompatible with graphs, indicate why"
2021-03-01Revert "commit-graph: when incompatible with graphs, indicate why"Libravatar Junio C Hamano1-11/+3
This reverts commit c85eec7fc37e1ca79072f263ae6ea1ee305ba38c, as it is a bit overzealous, we are in prerelease freeze, and we want to have enough time to get this right and cook in 'next'. cf. <8735xgkvuo.fsf@evledraar.gmail.com>
2021-02-25commit-graph: use config to specify generation typeLibravatar Derrick Stolee1-7/+15
We have two established generation number versions: 1: topological levels 2: corrected commit dates The corrected commit dates are enabled by default, but they also write extra data in the GDAT and GDOV chunks. Services that host Git data might want to have more control over when this feature rolls out than just updating the Git binaries. Add a new "commitGraph.generationVersion" config option that specifies the intended generation number version. If this value is less than 2, then the GDAT chunk is never written _or read_ from an existing file. This can replace our use of the GIT_TEST_COMMIT_GRAPH_NO_GDAT environment variable in the test suite. Remove it. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-25commit-graph: create local repository pointerLibravatar Derrick Stolee1-4/+5
The write_commit_graph() method uses 'the_repository' in a few places. A new need for a repository pointer is coming in the following change, so group these instances into a local variable 'r' that could eventually become part of the method signature, if so desired. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-24commit-graph.c: display correct number of chunks when writingLibravatar Taylor Blau1-4/+3
When writing a commit-graph, a progress meter is shown which indicates the number of pieces of data to write (one per commit in each chunk). In 47410aa837 (commit-graph: use chunk-format write API, 2021-02-18), the number of chunks became tracked by the new chunk-format API. But a stray local variable was left behind from when write_commit_graph_file() used to keep track of the same. Since this was no longer updated after 47410aa837, the progress meter appeared broken: $ git commit-graph write --reachable Expanding reachable commits in commit graph: 837569, done. Writing out commit graph in 3 passes: 166% (4187845/2512707), done. Drop the local variable and rely instead on the chunk-format API to tell us the correct number of chunks. Reported-by: SZEDER Gábor <szeder.dev@gmail.com> Signed-off-by: Taylor Blau <me@ttaylorr.com> Acked-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-22commit-graph: avoid leaking topo_levels slab in write_commit_graph()Libravatar Andrzej Hunt1-0/+1
write_commit_graph initialises topo_levels using init_topo_level_slab(), next it calls compute_topological_levels() which can cause the slab to grow, we therefore need to clear the slab again using clear_topo_level_slab() when we're done. First introduced in 72a2bfca (commit-graph: add a slab to store topological levels, 2021-01-16). LeakSanitizer output: ==1026==ERROR: LeakSanitizer: detected memory leaks Direct leak of 8 byte(s) in 1 object(s) allocated from: #0 0x498ae9 in realloc /src/llvm-project/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3 #1 0xafbed8 in xrealloc /src/git/wrapper.c:126:8 #2 0x7966d1 in topo_level_slab_at_peek /src/git/commit-graph.c:71:1 #3 0x7965e0 in topo_level_slab_at /src/git/commit-graph.c:71:1 #4 0x78fbf5 in compute_topological_levels /src/git/commit-graph.c:1472:12 #5 0x78c5c3 in write_commit_graph /src/git/commit-graph.c:2456:2 #6 0x535c5f in graph_write /src/git/builtin/commit-graph.c:299:6 #7 0x5350ca in cmd_commit_graph /src/git/builtin/commit-graph.c:337:11 #8 0x4cddb1 in run_builtin /src/git/git.c:453:11 #9 0x4cabe2 in handle_builtin /src/git/git.c:704:3 #10 0x4cd084 in run_argv /src/git/git.c:771:4 #11 0x4ca424 in cmd_main /src/git/git.c:902:19 #12 0x707fb6 in main /src/git/common-main.c:52:11 #13 0x7fee4249383f in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2083f) Indirect leak of 524256 byte(s) in 1 object(s) allocated from: #0 0x498942 in calloc /src/llvm-project/compiler-rt/lib/asan/asan_malloc_linux.cpp:154:3 #1 0xafc088 in xcalloc /src/git/wrapper.c:140:8 #2 0x796870 in topo_level_slab_at_peek /src/git/commit-graph.c:71:1 #3 0x7965e0 in topo_level_slab_at /src/git/commit-graph.c:71:1 #4 0x78fbf5 in compute_topological_levels /src/git/commit-graph.c:1472:12 #5 0x78c5c3 in write_commit_graph /src/git/commit-graph.c:2456:2 #6 0x535c5f in graph_write /src/git/builtin/commit-graph.c:299:6 #7 0x5350ca in cmd_commit_graph /src/git/builtin/commit-graph.c:337:11 #8 0x4cddb1 in run_builtin /src/git/git.c:453:11 #9 0x4cabe2 in handle_builtin /src/git/git.c:704:3 #10 0x4cd084 in run_argv /src/git/git.c:771:4 #11 0x4ca424 in cmd_main /src/git/git.c:902:19 #12 0x707fb6 in main /src/git/common-main.c:52:11 #13 0x7fee4249383f in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2083f) SUMMARY: AddressSanitizer: 524264 byte(s) leaked in 2 allocation(s). Signed-off-by: Andrzej Hunt <ajrhunt@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-18commit-graph: use chunk-format read APILibravatar Derrick Stolee1-105/+54
Instead of parsing the table of contents directly, use the chunk-format API methods read_table_of_contents() and pair_chunk(). While the current implementation loses the duplicate-chunk detection, that will be added in a future change. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-18commit-graph: use chunk-format write APILibravatar Derrick Stolee1-82/+37
The commit-graph write logic is ready to make use of the chunk-format write API. Each chunk write method is already in the correct prototype. We only need to use the 'struct chunkfile' pointer and the correct API calls. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-17Merge branch 'js/commit-graph-warning'Libravatar Junio C Hamano1-3/+11
When certain features (e.g. grafts) used in the repository are incompatible with the use of the commit-graph, we used to silently turned commit-graph off; we now tell the user what we are doing. * js/commit-graph-warning: commit-graph: when incompatible with graphs, indicate why
2021-02-17Merge branch 'ds/commit-graph-genno-fix'Libravatar Junio C Hamano1-37/+101
Fix incremental update of commit-graph file around corrected commit date data. * ds/commit-graph-genno-fix: commit-graph: prepare commit graph commit-graph: be extra careful about mixed generations commit-graph: compute generations separately commit-graph: validate layers for generation data commit-graph: always parse before commit_graph_data_at() commit-graph: use repo_parse_commit
2021-02-17Merge branch 'ak/corrected-commit-date'Libravatar Junio C Hamano1-47/+204
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
2021-02-11commit-graph: when incompatible with graphs, indicate whyLibravatar Johannes Schindelin1-3/+11
When `gc.writeCommitGraph = true`, it is possible that the commit-graph is _still_ not written: replace objects, grafts and shallow repositories are incompatible with the commit-graph feature. Under such circumstances, we need to indicate to the user why the commit-graph was not written instead of staying silent about it. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Acked-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-10Merge branch 'jk/use-oid-pos'Libravatar Junio C Hamano1-15/+15
Code clean-up to ensure our use of hashtables using object names as keys use the "struct object_id" objects, not the raw hash values. * jk/use-oid-pos: oid_pos(): access table through const pointers hash_pos(): convert to oid_pos() rerere: use strmap to store rerere directories rerere: tighten rr-cache dirname check rerere: check dirname format while iterating rr_cache directory commit_graft_pos(): take an oid instead of a bare hash
2021-02-05commit-graph: anonymize data in chunk_write_fnLibravatar Derrick Stolee1-10/+19
In preparation for creating an API around file formats using chunks and tables of contents, prepare the commit-graph write code to use prototypes that will match this new API. Specifically, convert chunk_write_fn to take a "void *data" parameter instead of the commit-graph-specific "struct write_commit_graph_context" pointer. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-03Merge branch 'jk/peel-iterated-oid'Libravatar Junio C Hamano1-1/+1
The peel_ref() API has been replaced with peel_iterated_oid(). * jk/peel-iterated-oid: refs: switch peel_ref() to peel_iterated_oid()
2021-02-01commit-graph: prepare commit graphLibravatar Derrick Stolee1-8/+2
Before checking if the repository has a commit-graph loaded, be sure to run prepare_commit_graph(). This is necessary because otherwise the topo_levels slab is not initialized. As we compute topo_levels for the new commits, we iterate further into the lower layers since the first visit to each commit looks as though the topo_level is not populated. By properly initializing the topo_slab, we fix the previously broken case of a split commit graph where a base layer has the generation_data_overflow chunk. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Reviewed-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-01commit-graph: be extra careful about mixed generationsLibravatar Derrick Stolee1-2/+12
When upgrading to a commit-graph with corrected commit dates from one without, there are a few things that need to be considered. When computing generation numbers for the new commit-graph file that expects to add the generation_data chunk with corrected commit dates, we need to ensure that the 'generation' member of the commit_graph_data struct is set to zero for these commits. Unfortunately, the fallback to use topological level for generation number when corrected commit dates are not available are causing us harm here: parsing commits notices that read_generation_data is false and populates 'generation' with the topological level. The solution is to iterate through the commits, parse the commits to populate initial values, then reset the generation values to zero to trigger recalculation. This loop only occurs when the existing commit-graph data has no corrected commit dates. While this improves our situation somewhat, we have not completely solved the issue for correctly computing generation numbers for mixed layers. That follows in the next change. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Reviewed-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-01commit-graph: compute generations separatelyLibravatar Derrick Stolee1-14/+56
The compute_generation_numbers() method was introduced by 3258c663 (commit-graph: compute generation numbers, 2018-05-01) to compute what is now known as "topological levels". These are still stored in the commit-graph file for compatibility sake while c1a09119 (commit-graph: implement corrected commit date, 2021-01-16) updated the method to also compute the new version of generation numbers: corrected commit date. It makes sense why these are grouped. They perform very similar walks of the necessary commits and compute similar maximums over each parent. However, having these two together conflates them in subtle ways that is hard to separate. In particular, the topo_level slab is used to store the topological levels in all cases, but the commit_graph_data_at(c)->generation member stores different values depending on the state of the existing commit-graph file. * If the existing commit-graph file has a "GDAT" chunk, then these values represent corrected commit dates. * If the existing commit-graph file doesn't have a "GDAT" chunk, then these values are actually the topological levels. This issue only occurs only when upgrading an existing commit-graph file into one that has the "GDAT" chunk. The current change does not resolve this upgrade problem, but splitting the implementation into two pieces here helps with that process, which will follow in the next change. The important thing this helps with is the case where the num_generation_data_overflows was being incremented incorrectly, triggering a write of the overflow chunk. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Reviewed-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-01commit-graph: validate layers for generation dataLibravatar Derrick Stolee1-6/+16
We need to be extra careful that we don't use corrected commit dates from any layer of a commit-graph chain if there is a single commit-graph file that is missing the generation_data chunk. Update validate_mixed_generation_chain() to correctly update each layer to ignore the generation_data chunk in this case. It now also returns 1 if all layers have a generation_data chunk. This return value will be used in the next change. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Reviewed-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-01commit-graph: always parse before commit_graph_data_at()Libravatar Derrick Stolee1-4/+12
There is a subtle failure happening when computing corrected commit dates with --split enabled. It requires a base layer needing the generation_data_overflow chunk. Then, the next layer on top erroneously thinks it needs an overflow chunk due to a bug leading to recalculating all reachable generation numbers. The output of the failure is BUG: commit-graph.c:1912: expected to write 8 bytes to chunk 47444f56, but wrote 0 instead These "expected" 8 bytes are due to re-computing the corrected commit date for the lower layer but the new layer does not need any overflow. Add a test to t5318-commit-graph.sh that demonstrates this bug. However, it does not trigger consistently with the existing code. The generation number data is stored in a slab and accessed by commit_graph_data_at(). This data is initialized when parsing a commit, but is otherwise used assuming it has been populated. The loop in compute_generation_numbers() did not enforce that all reachable commits were parsed and had correct values. This could lead to some problems when writing a commit-graph with corrected commit dates based on a commit-graph without them. It has been difficult to identify the issue here because it was so hard to reproduce. It relies on this uninitialized data having a non-zero value, but also on specifically in a way that overwrites the existing data. This patch adds the extra parse to ensure the data is filled before we compute the generation number of a commit. This triggers the new test to fail because the generation number overflow count does not match between this computation and the write for that chunk. The actual fix will follow as the next few changes. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Reviewed-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-01commit-graph: use repo_parse_commitLibravatar Derrick Stolee1-5/+5
The write_commit_graph_context has a repository pointer, so use it. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Reviewed-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-28oid_pos(): access table through const pointersLibravatar Jeff King1-2/+2
When we are looking up an oid in an array, we obviously don't need to write to the array. Let's mark it as const in the function interfaces, as well as in the local variables we use to derference the void pointer (note a few cases use pointers-to-pointers, so we mark everything const). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-28hash_pos(): convert to oid_pos()Libravatar Jeff King1-14/+14
All of our callers are actually looking up an object_id, not a bare hash. Likewise, the arrays they are looking in are actual arrays of object_id (not just raw bytes of hashes, as we might find in a pack .idx; those are handled by bsearch_hash()). Using an object_id gives us more type safety, and makes the callers slightly shorter. It also gets rid of the word "sha1" from several access functions, though we could obviously also rename those with s/sha1/hash/. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-25Merge branch 'ma/more-opaque-lock-file'Libravatar Junio C Hamano1-3/+3
Code clean-up. * ma/more-opaque-lock-file: read-cache: try not to peek into `struct {lock_,temp}file` refs/files-backend: don't peek into `struct lock_file` midx: don't peek into `struct lock_file` commit-graph: don't peek into `struct lock_file` builtin/gc: don't peek into `struct lock_file`
2021-01-21refs: switch peel_ref() to peel_iterated_oid()Libravatar Jeff King1-1/+1
The peel_ref() interface is confusing and error-prone: - it's typically used by ref iteration callbacks that have both a refname and oid. But since they pass only the refname, we may load the ref value from the filesystem again. This is inefficient, but also means we are open to a race if somebody simultaneously updates the ref. E.g., this: int some_ref_cb(const char *refname, const struct object_id *oid, ...) { if (!peel_ref(refname, &peeled)) printf("%s peels to %s", oid_to_hex(oid), oid_to_hex(&peeled); } could print nonsense. It is correct to say "refname peels to..." (you may see the "before" value or the "after" value, either of which is consistent), but mentioning both oids may be mixing before/after values. Worse, whether this is possible depends on whether the optimization to read from the current iterator value kicks in. So it is actually not possible with: for_each_ref(some_ref_cb); but it _is_ possible with: head_ref(some_ref_cb); which does not use the iterator mechanism (though in practice, HEAD should never peel to anything, so this may not be triggerable). - it must take a fully-qualified refname for the read_ref_full() code path to work. Yet we routinely pass it partial refnames from callbacks to for_each_tag_ref(), etc. This happens to work when iterating because there we do not call read_ref_full() at all, and only use the passed refname to check if it is the same as the iterator. But the requirements for the function parameters are quite unclear. Instead of taking a refname, let's instead take an oid. That fixes both problems. It's a little funny for a "ref" function not to involve refs at all. The key thing is that it's optimizing under the hood based on having access to the ref iterator. So let's change the name to make it clear why you'd want this function versus just peel_object(). There are two other directions I considered but rejected: - we could pass the peel information into the each_ref_fn callback. However, we don't know if the caller actually wants it or not. For packed-refs, providing it is essentially free. But for loose refs, we actually have to peel the object, which would be wasteful in most cases. We could likewise pass in a flag to the callback indicating whether the peeled information is known, but that complicates those callbacks, as they then have to decide whether to manually peel themselves. Plus it requires changing the interface of every callback, whether they care about peeling or not, and there are many of them. - we could make a function to return the peeled value of the current iterated ref (computing it if necessary), and BUG() otherwise. I.e.: int peel_current_iterated_ref(struct object_id *out); Each of the current callers is an each_ref_fn callback, so they'd mostly be happy. But: - we use those callbacks with functions like head_ref(), which do not use the iteration code. So we'd need to handle the fallback case there, anyway. - it's possible that a caller would want to call into generic code that sometimes is used during iteration and sometimes not. This encapsulates the logic to do the fast thing when possible, and fallback when necessary. The implementation is mostly obvious, but I want to call out a few things in the patch: - the test-tool coverage for peel_ref() is now meaningless, as it all collapses to a single peel_object() call (arguably they were pretty uninteresting before; the tricky part of that function is the fast-path we see during iteration, but these calls didn't trigger that). I've just dropped it entirely, though note that some other tests relied on the tags we created; I've moved that creation to the tests where it matters. - we no longer need to take a ref_store parameter, since we'd never look up a ref now. We do still rely on a global "current iterator" variable which _could_ be kept per-ref-store. But in practice this is only useful if there are multiple recursive iterations, at which point the more appropriate solution is probably a stack of iterators. No caller used the actual ref-store parameter anyway (they all call the wrapper that passes the_repository). - the original only kicked in the optimization when the "refname" pointer matched (i.e., not string comparison). We do likewise with the "oid" parameter here, but fall back to doing an actual oideq() call. This in theory lets us kick in the optimization more often, though in practice no current caller cares. It should never be wrong, though (peeling is a property of an object, so two refs pointing to the same object would peel identically). - the original took care not to touch the peeled out-parameter unless we found something to put in it. But no caller cares about this, and anyway, it is enforced by peel_object() itself (and even in the optimized iterator case, that's where we eventually end up). We can shorten the code and avoid an extra copy by just passing the out-parameter through the stack. Signed-off-by: Jeff King <peff@peff.net> Reviewed-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>