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2026-03-05Merge branch 'ps/fsck-stream-from-the-right-object-instance'Junio C Hamano
"fsck" iterates over packfiles and its access to pack data caused the list to be permuted, which caused it to loop forever; the code to access pack data by "fsck" has been updated to avoid this. * ps/fsck-stream-from-the-right-object-instance: pack-check: fix verification of large objects packfile: expose function to read object stream for an offset object-file: adapt `stream_object_signature()` to take a stream t/helper: improve "genrandom" test helper
2026-02-24t: disable maintenance where we verify object database structurePatrick Steinhardt
We have a couple of tests that explicitly verify the structure of the object database. Naturally, this structure is dependent on whether or not we run repository maintenance: if it decides to optimize the object database the expected structure is likely to not materialize. Explicitly disable auto-maintenance in such tests so that we are not dependent on decisions made by our maintenance. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-02-23t/helper: improve "genrandom" test helperPatrick Steinhardt
The `test-tool genrandom` test helper can be used to generate random data, either as an infinite stream or with a specified number of bytes. The way we handle parsing the number of bytes is lacking though: - We don't have good error handling, so if the caller for example uses `test-tool genrandom 200xyz` then we'll end up generating 200 bytes of random data successfully. - Many callers want to generate e.g. 1 kilobyte or megabyte of data, but they have to either use unwieldy numbers like 1048576, or they have to precompute them. Fix both of these issues by using `git_parse_ulong()` to parse the argument. This function has better error handling, and it knows to handle unit suffixes. Adapt a couple of our tests to use suffixes instead of manual computations. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-08-25path-walk: fix setup of pending objectsDerrick Stolee
Users reported an issue where objects were missing from their local repositories after a full repack using 'git repack -adf --path-walk'. This was alarming and took a while to create a reproducer. Here, we fix the bug and include a test case that would fail without this fix. The root cause is that certain objects existed in the index and had no second versions. These objects are usually blobs, though trees can be included if a cache-tree exists. The issue is that the revision walk adds these objects to the "pending" list and the path-walk API forgets to mark the lists it creates at this point as "maybe_interesting". If these paths only ever have a single version in the history of the repo (including the current staged version) then the parent directory never tries to add a new object to the list and mark the list as "maybe_interesting". Thus, when walking the list later, the group is skipped as it is expected that no objects are interesting. This happens even when there are actually no UNINTERESTING objects at all! This is based on the optimization enabled by the pack.useSparse=true config option, which is the default. Thus, we create a test case that demonstrates the many cases of this issue for reproducibility: 1. File a/b/c has only one committed version. 2. Files a/i and x/y only exist as staged changes. 3. Tree x/ only exists in the cache-tree. After performing a non-path-walk repack to force all loose objects into packfiles, run a --path-walk repack followed by 'git fsck'. This fsck is what fails with the following errors: error: invalid object 100644 f2e41136... for 'a/b/c' This is the dropped instance of the single-versioned a/b/c file. broken link from tree cfda31d8... to tree 3f725fcd... This is the missing tree for the single-versioned a/b/ directory. missing blob 0ddf2bae... (a/i) missing blob 975fbec8... (x/y) missing blob a60d869d... (file) missing blob f2e41136... (a/b/c) missing tree 3f725fcd... (a/b/) dangling tree 5896d7e... (staged root tree) Note that since the staged root tree is missing, the fsck output cannot even report that the staged x/ tree is missing as well. The core problem here is that the "maybe_interesting" member of 'struct type_and_oid_list' is not initialized to '1'. This member was added in 6333e7ae0b (path-walk: mark trees and blobs as UNINTERESTING, 2024-12-20) in a way to help when creating packfiles for a small commit range using the sparse path algorithm (enabled by pack.useSparse=true). The idea here is that the list is marked as "maybe_interesting" if an object is added that does not have the UNINTERESTING flag on it. Later, this is checked again in case all objects in the list were marked UNINTERESTING after that point in time. In this case, the algorithm skips the list as there is no reason to visit it. This leads to the problem where the "maybe_interesting" member was not appropriately initialized when the list is created from pending objects. Initializing this in the correct places fixes the bug. To reduce risk of similar bugs around initializing this structure, a follow-up change will make initializing lists use a shared method. Signed-off-by: Derrick Stolee <stolee@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-02-12Merge branch 'ds/name-hash-tweaks'Junio C Hamano
"git pack-objects" and its wrapper "git repack" learned an option to use an alternative path-hash function to improve delta-base selection to produce a packfile with deeper history than window size. * ds/name-hash-tweaks: pack-objects: prevent name hash version change test-tool: add helper for name-hash values p5313: add size comparison test pack-objects: add GIT_TEST_NAME_HASH_VERSION repack: add --name-hash-version option pack-objects: add --name-hash-version option pack-objects: create new name-hash function version
2025-01-27pack-objects: add GIT_TEST_NAME_HASH_VERSIONDerrick Stolee
Add a new environment variable to opt-in to different values of the --name-hash-version=<n> option in 'git pack-objects'. This allows for extra testing of the feature without repeating all of the test scenarios. Unlike many GIT_TEST_* variables, we are choosing to not add this to the linux-TEST-vars CI build as that test run is already overloaded. The behavior exposed by this test variable is of low risk and should be sufficient to allow manual testing when an issue arises. But this option isn't free. There are a few tests that change behavior with the variable enabled. First, there are a few tests that are very sensitive to certain delta bases being picked. These are both involving the generation of thin bundles and then counting their objects via 'git index-pack --fix-thin' which pulls the delta base into the new packfile. For these tests, disable the option as a decent long-term option. Second, there are some tests that compare the exact output of a 'git pack-objects' process when using bitmaps. The warning that ignores the --name-hash-version=2 and forces version 1 causes these tests to fail. Disable the environment variable to get around this issue. Signed-off-by: Derrick Stolee <stolee@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-01-27repack: add --name-hash-version optionDerrick Stolee
The new '--name-hash-version' option for 'git repack' is a simple pass-through to the underlying 'git pack-objects' subcommand. However, this subcommand may have other options and a temporary filename as part of the subcommand execution that may not be predictable or could change over time. The existing test_subcommand method requires an exact list of arguments for the subcommand. This is too rigid for our needs here, so create a new method, test_subcommand_flex. Use it to check that the --name-hash-version option is passing through. Since we are modifying the 'git repack' command, let's bring its usage in line with the Documentation's synopsis. This removes it from the allow list in t0450 so it will remain in sync in the future. Signed-off-by: Derrick Stolee <stolee@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-11-21t: remove TEST_PASSES_SANITIZE_LEAK annotationsPatrick Steinhardt
Now that the default value for TEST_PASSES_SANITIZE_LEAK is `true` there is no longer a need to have that variable declared in all of our tests. Drop it. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-09-27builtin/repack: fix leaking configurationPatrick Steinhardt
When repacking, we assemble git-pack-objects(1) arguments both for the "normal" pack and for the cruft pack. This configuration gets populated with a bunch of `OPT_PASSTHRU` options that we end up passing to the child process. These options are allocated, but never free'd. Create a new `pack_objects_args_release()` function that releases the memory for us and call it for both sets of options. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-08-06midx: implement support for writing incremental MIDX chainsTaylor Blau
Now that the rest of the MIDX subsystem and relevant callers have been updated to learn about how to read and process incremental MIDX chains, let's finally update the implementation in `write_midx_internal()` to be able to write incremental MIDX chains. This new feature is available behind the `--incremental` option for the `multi-pack-index` builtin, like so: $ git multi-pack-index write --incremental The implementation for doing so is relatively straightforward, and boils down to a handful of different kinds of changes implemented in this patch: - The `compute_sorted_entries()` function is taught to reject objects which appear in any existing MIDX layer. - Functions like `write_midx_revindex()` are adjusted to write pack_order values which are offset by the number of objects in the base MIDX layer. - The end of `write_midx_internal()` is adjusted to move non-incremental MIDX files when necessary (i.e. when creating an incremental chain with an existing non-incremental MIDX in the repository). There are a handful of other changes that are introduced, like new functions to clear incremental MIDX files that are unrelated to the current chain (using the same "keep_hash" mechanism as in the non-incremental case). The tests explicitly exercising the new incremental MIDX feature are relatively limited for two reasons: 1. Most of the "interesting" behavior is already thoroughly covered in t5319-multi-pack-index.sh, which handles the core logic of reading objects through a MIDX. The new tests in t5334-incremental-multi-pack-index.sh are mostly focused on creating and destroying incremental MIDXs, as well as stitching their results together across layers. 2. A new GIT_TEST environment variable is added called "GIT_TEST_MULTI_PACK_INDEX_WRITE_INCREMENTAL", which modifies the entire test suite to write incremental MIDXs after repacking when combined with the "GIT_TEST_MULTI_PACK_INDEX" variable. This exercises the long tail of other interesting behavior that is defined implicitly throughout the rest of the CI suite. It is likewise added to the linux-TEST-vars job. Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-08-06t: retire 'GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP'Taylor Blau
Two years ago, commit ff1e653c8e2 (midx: respect 'GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP', 2021-08-31) introduced a new environment variable which caused the test suite to write MIDX bitmaps after any 'git repack' invocation. At the time, this was done to help flush out any bugs with MIDX bitmaps that weren't explicitly covered in the t5326-multi-pack-bitmap.sh script. Two years later, that flag has served us well and is no longer providing meaningful coverage, as the script in t5326 has matured substantially and covers many more interesting cases than it did back when ff1e653c8e2 was originally written. Remove the 'GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP' environment variable as it is no longer serving a useful purpose. More importantly, removing this variable clears the way for us to introduce a new one to help similarly flush out bugs related to incremental MIDX chains. Because these incremental MIDX chains are (for now) incompatible with MIDX bitmaps, we cannot have both. Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-04-03t/t7700-repack.sh: fix test breakages with `GIT_TEST_MULTI_PACK_INDEX=1 `Taylor Blau
There are a handful of related test breakages which are found when running t/t7700-repack.sh with GIT_TEST_MULTI_PACK_INDEX set to "1" in your environment. Both test failures are the result of something like: git repack --write-midx --write-bitmap-index [...] && test_path_is_file $midx && test_path_is_file $midx-$(midx_checksum $objdir).bitmap , where we repack instructing Git to write a new MIDX and corresponding MIDX bitamp. The error occurs when GIT_TEST_MULTI_PACK_INDEX=1 is found in the enviornment. This causes Git to write out a second MIDX (after processing the builtin's `--write-midx` argument) which is identical to the first, but does not request a bitmap (since we did not set the GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP variable in the environment). Since c528e179662 (pack-bitmap: write multi-pack bitmaps, 2021-08-31), the MIDX machinery will drop an existing MIDX bitmap when rewriting an identical MIDX which does not itself request a corresponding bitmap, which is similar to the way repack itself behaves in the pack-bitmap case. Correct these issues (which date back to [1] and [2], respectively) by explicitly setting GIT_TEST_MULTI_PACK_INDEX to zero before running each command. In the future, we should consider removing GIT_TEST_MULTI_PACK_INDEX, and in general clean up unused GIT_TEST_-variables. But that is a larger effort, and this ensures that we can cleanly run: $ GIT_TEST_MULTI_PACK_INDEX=1 make test in the meantime. [1]: 324efc90d1b (builtin/repack.c: pass `--refs-snapshot` when writing bitmaps, 2021-10-01) [2]: 197443e80ab (repack: don't remove .keep packs with `--pack-kept-objects`, 2022-10-17). Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-11-26commit-graph: disable GIT_COMMIT_GRAPH_PARANOIA by defaultPatrick Steinhardt
In 7a5d604443 (commit: detect commits that exist in commit-graph but not in the ODB, 2023-10-31), we have introduced a new object existence check into `repo_parse_commit_internal()` so that we do not parse commits via the commit-graph that don't have a corresponding object in the object database. This new check of course comes with a performance penalty, which the commit put at around 30% for `git rev-list --topo-order`. But there are in fact scenarios where the performance regression is even higher. The following benchmark against linux.git with a fully-build commit-graph: Benchmark 1: git.v2.42.1 rev-list --count HEAD Time (mean ± σ): 658.0 ms ± 5.2 ms [User: 613.5 ms, System: 44.4 ms] Range (min … max): 650.2 ms … 666.0 ms 10 runs Benchmark 2: git.v2.43.0-rc1 rev-list --count HEAD Time (mean ± σ): 1.333 s ± 0.019 s [User: 1.263 s, System: 0.069 s] Range (min … max): 1.302 s … 1.361 s 10 runs Summary git.v2.42.1 rev-list --count HEAD ran 2.03 ± 0.03 times faster than git.v2.43.0-rc1 rev-list --count HEAD While it's a noble goal to ensure that results are the same regardless of whether or not we have a potentially stale commit-graph, taking twice as much time is a tough sell. Furthermore, we can generally assume that the commit-graph will be updated by git-gc(1) or git-maintenance(1) as required so that the case where the commit-graph is stale should not at all be common. With that in mind, default-disable GIT_COMMIT_GRAPH_PARANOIA and restore the behaviour and thus performance previous to the mentioned commit. In order to not be inconsistent, also disable this behaviour by default in `lookup_commit_in_graph()`, where the object existence check has been introduced right at its inception via f559d6d45e (revision: avoid hitting packfiles when commits are in commit-graph, 2021-08-09). This results in another speedup in commands that end up calling this function, even though it's less pronounced compared to the above benchmark. The following has been executed in linux.git with ~1.2 million references: Benchmark 1: GIT_COMMIT_GRAPH_PARANOIA=true git rev-list --all --no-walk=unsorted Time (mean ± σ): 2.947 s ± 0.003 s [User: 2.412 s, System: 0.534 s] Range (min … max): 2.943 s … 2.949 s 3 runs Benchmark 2: GIT_COMMIT_GRAPH_PARANOIA=false git rev-list --all --no-walk=unsorted Time (mean ± σ): 2.724 s ± 0.030 s [User: 2.207 s, System: 0.514 s] Range (min … max): 2.704 s … 2.759 s 3 runs Summary GIT_COMMIT_GRAPH_PARANOIA=false git rev-list --all --no-walk=unsorted ran 1.08 ± 0.01 times faster than GIT_COMMIT_GRAPH_PARANOIA=true git rev-list --all --no-walk=unsorted So whereas 7a5d604443 initially introduced the logic to start doing an object existence check in `repo_parse_commit_internal()` by default, the updated logic will now instead cause `lookup_commit_in_graph()` to stop doing the check by default. This behaviour continues to be tweakable by the user via the GIT_COMMIT_GRAPH_PARANOIA environment variable. Note that this requires us to amend some tests to manually turn on the paranoid checks again. This is because we cause repository corruption by manually deleting objects which are part of the commit graph already. These circumstances shouldn't usually happen in repositories. Reported-by: Jeff King <peff@peff.net> Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-10-18Merge branch 'tb/repack-max-cruft-size'Junio C Hamano
"git repack" learned "--max-cruft-size" to prevent cruft packs from growing without bounds. * tb/repack-max-cruft-size: repack: free existing_cruft array after use builtin/repack.c: avoid making cruft packs preferred builtin/repack.c: implement support for `--max-cruft-size` builtin/repack.c: parse `--max-pack-size` with OPT_MAGNITUDE t7700: split cruft-related tests to t7704
2023-10-02t7700: split cruft-related tests to t7704Taylor Blau
A small handful of the tests in t7700 (the main script for testing functionality of 'git repack') are specifically related to cruft pack operations. Prepare for adding new cruft pack-related tests by moving the existing set into a new test script. Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-10-02repack: implement `--filter-to` for storing filtered out objectsChristian Couder
A previous commit has implemented `git repack --filter=<filter-spec>` to allow users to filter out some objects from the main pack and move them into a new different pack. It would be nice if this new different pack could be created in a different directory than the regular pack. This would make it possible to move large blobs into a pack on a different kind of storage, for example cheaper storage. Even in a different directory, this pack can be accessible if, for example, the Git alternates mechanism is used to point to it. In fact not using the Git alternates mechanism can corrupt a repo as the generated pack containing the filtered objects might not be accessible from the repo any more. So setting up the Git alternates mechanism should be done before using this feature if the user wants the repo to be fully usable while this feature is used. In some cases, like when a repo has just been cloned or when there is no other activity in the repo, it's Ok to setup the Git alternates mechanism afterwards though. It's also Ok to just inspect the generated packfile containing the filtered objects and then just move it into the '.git/objects/pack/' directory manually. That's why it's not necessary for this command to check that the Git alternates mechanism has been already setup. While at it, as an example to show that `--filter` and `--filter-to` work well with other options, let's also add a test to check that these options work well with `--max-pack-size`. Signed-off-by: Christian Couder <chriscool@tuxfamily.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-10-02repack: add `--filter=<filter-spec>` optionChristian Couder
This new option puts the objects specified by `<filter-spec>` into a separate packfile. This could be useful if, for example, some blobs take up a lot of precious space on fast storage while they are rarely accessed. It could make sense to move them into a separate cheaper, though slower, storage. It's possible to find which new packfile contains the filtered out objects using one of the following: - `git verify-pack -v ...`, - `test-tool find-pack ...`, which a previous commit added, - `--filter-to=<dir>`, which a following commit will add to specify where the pack containing the filtered out objects will be. This feature is implemented by running `git pack-objects` twice in a row. The first command is run with `--filter=<filter-spec>`, using the specified filter. It packs objects while omitting the objects specified by the filter. Then another `git pack-objects` command is launched using `--stdin-packs`. We pass it all the previously existing packs into its stdin, so that it will pack all the objects in the previously existing packs. But we also pass into its stdin, the pack created by the previous `git pack-objects --filter=<filter-spec>` command as well as the kept packs, all prefixed with '^', so that the objects in these packs will be omitted from the resulting pack. The result is that only the objects filtered out by the first `git pack-objects` command are in the pack resulting from the second `git pack-objects` command. As the interactions with kept packs are a bit tricky, a few related tests are added. Helped-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: John Cai <johncai86@gmail.com> Signed-off-by: Christian Couder <chriscool@tuxfamily.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11builtin/repack.c: only repack `.pack`s that existDerrick Stolee
In 73320e49add (builtin/repack.c: only collect fully-formed packs, 2023-06-07), we switched the check for which packs to collect by starting at the .idx files and looking for matching .pack files. This avoids trying to repack pack-files that have not had their pack-indexes installed yet. However, it does cause maintenance to halt if we find the (problematic, but not insurmountable) case of a .idx file without a corresponding .pack file. In an environment where packfile maintenance is a critical function, such a hard stop is costly and requires human intervention to resolve (by deleting the .idx file). This was not the case before. We successfully repacked through this scenario until the recent change to scan for .idx files. Further, if we are actually in a case where objects are missing, we detect this at a different point during the reachability walk. In other cases, Git prepares its list of packfiles by scanning .idx files and then only adds it to the packfile list if the corresponding .pack file exists. It even does so without a warning! (See add_packed_git() in packfile.c for details.) This case is much less likely to occur than the failures seen before 73320e49add. Packfiles are "installed" by writing the .pack file before the .idx and that process can be interrupted. Packfiles _should_ be deleted by deleting the .idx first, followed by the .pack file, but unlink_pack_path() does not do this: it deletes the .pack _first_, allowing a window where this process could be interrupted. We leave the consideration of changing this order as a separate concern. Knowing that this condition is possible from interrupted Git processes and not other tools lends some weight that Git should be more flexible around this scenario. Add a check to see if the .pack file exists before adding it to the list for repacking. This will stop a number of maintenance failures seen in production but fixed by deleting the .idx files. This brings us closer to the case before 73320e49add in that 'git repack' will not fail when there is an orphaned .idx file, at least, not due to the way we scan for packfiles. In the case that the .pack file was erroneously deleted without copies of its objects in other installed packfiles, then 'git repack' will fail due to the reachable object walk. This does resolve the case where automated repacks will no longer be halted on this case. The tests in t7700 show both these successful scenarios and the case of failing if the .pack was truly required. Signed-off-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-26Merge branch 'tb/collect-pack-filenames-fix'Junio C Hamano
Avoid breakage of "git pack-objects --cruft" due to inconsistency between the way the code enumerates packfiles in the repository. * tb/collect-pack-filenames-fix: builtin/repack.c: only collect fully-formed packs
2023-06-12builtin/repack.c: only collect fully-formed packsTaylor Blau
To partition the set of packs based on which ones are "kept" (either they have a .keep file, or were otherwise marked via the `--keep-pack` option) and "non-kept" ones (anything else), `git repack` uses its `collect_pack_filenames()` function. Ordinarily, we would rely on a convenience function such as `get_all_packs()` to enumerate and partition the set of packs. But `collect_pack_filenames()` uses `readdir()` directly to read the contents of the "$GIT_DIR/objects/pack" directory, and adds each entry ending in ".pack" to the appropriate list (either kept, or non-kept as above). This is subtly racy, since `collect_pack_filenames()` may see a pack that is not fully staged (i.e., it is missing its ".idx" file). Ordinarily, this doesn't cause a problem. But it can cause issues when generating a cruft pack. This is because `git repack` feeds (among other things) the list of existing kept packs down to `git pack-objects --cruft` to indicate that any kept packs will not be removed from the repository (so that the cruft pack machinery can avoid packing objects that appear in those packs as cruft). But `read_cruft_objects()` lists packfiles by calling `get_all_packs()`. So if a ".pack" file exists (necessary to get that pack to appear to `collect_pack_filenames()`), but doesn't have a corresponding ".idx" file (necessary to get that pack to appear via `get_all_packs()`), we'll complain with: fatal: could not find pack '.tmp-5841-pack-a6b0150558609c323c496ced21de6f4b66589260.pack' Fix the above by teaching `collect_pack_filenames()` to only collect packs with their corresponding `*.idx` files in place, indicating that those packs have been fully staged. There are a couple of things worth noting: - Since each entry in the `extra_keep` list (which contains the `--keep-pack` names) has a `*.pack` suffix, we'll have to swap the suffix from ".pack" to ".idx", and compare that instead. - Since we use the the `fname_kept_list` to figure out which packs to delete (with `git repack -d`), we would have previously deleted a `*.pack` with no index (since the existince of a ".pack" file is necessary and sufficient to include that pack in the list of existing non-kept packs). Now we will leave it alone (since that pack won't appear in the list). This is far more correct behavior, since we don't want to race with a pack being staged. Deleting a partially staged pack is unlikely, however, since the window of time between staging a pack and moving its .idx file into place is miniscule. Note that this window does *not* include the time it takes to receive and index the pack, since the incoming data goes into "$GIT_DIR/objects/tmp_pack_XXXXXX", which does not end in ".pack" and is thus ignored by collect_pack_filenames(). In the future, this function should probably be rewritten as a callback to `for_each_file_in_pack_dir()`, but this is the simplest change we could do in the short-term. Reported-by: Michael Haggerty <mhagger@github.com> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-05-23t7700-repack: modernize test formatJohn Cai
Some tests still use the old format with four spaces indentation. Standardize the tests to the new format with tab indentation. Signed-off-by: John Cai <johncai86@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-04-14repack: disable writing bitmaps when doing a local repackPatrick Steinhardt
In order to write a bitmap, we need to have full coverage of all objects that are about to be packed. In the traditional non-multi-pack-index world this meant we need to do a full repack of all objects into a single packfile. But in the new multi-pack-index world we can get away with writing bitmaps when we have multiple packfiles as long as the multi-pack-index covers all objects. This is not always the case though. When asked to perform a repack of local objects, only, then we cannot guarantee to have full coverage of all objects regardless of whether we do a full repack or a repack with a multi-pack-index. The end result is that writing the bitmap will fail in both worlds: $ git multi-pack-index write --stdin-packs --bitmap <packfiles warning: Failed to write bitmap index. Packfile doesn't have full closure (object 1529341d78cf45377407369acb0f4ff2b5cdae42 is missing) error: could not write multi-pack bitmap Now there are two different ways to fix this. The first one would be to amend git-multi-pack-index(1) to disable writing bitmaps when we notice that we don't have full object coverage. - We don't have enough information in git-multi-pack-index(1) in order to tell whether the local repository _should_ have full coverage. Because even when connected to an alternate object directory, it may be the case that we still have all objects around in the main object database. - git-multi-pack-index(1) is quite a low-level tool. Automatically disabling functionality that it was asked to provide does not feel like the right thing to do. We can easily fix it at a higher level in git-repack(1) though. When asked to only include local objects via `-l` and when connected to an alternate object directory then we will override the user's ask and disable writing bitmaps with a warning. This is similar to what we do in git-pack-objects(1), where we also disable writing bitmaps in case we omit an object from the pack. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-11-29Merge branch 'gc/resolve-alternate-symlinks'Junio C Hamano
Resolve symbolic links when processing the locations of alternate object stores, since failing to do so can lead to confusing and buggy behavior. * gc/resolve-alternate-symlinks: object-file: use real paths when adding alternates
2022-11-25object-file: use real paths when adding alternatesGlen Choo
When adding an alternate ODB, we check if the alternate has the same path as the object dir, and if so, we do nothing. However, that comparison does not resolve symlinks. This makes it possible to add the object dir as an alternate, which may result in bad behavior. For example, it can trick "git repack -a -l -d" (possibly run by "git gc") into thinking that all packs come from an alternate and delete all objects. rm -rf test && git clone https://github.com/git/git test && ( cd test && ln -s objects .git/alt-objects && # -c repack.updateserverinfo=false silences a warning about not # being able to update "info/refs", it isn't needed to show the # bad behavior GIT_ALTERNATE_OBJECT_DIRECTORIES=".git/alt-objects" git \ -c repack.updateserverinfo=false repack -a -l -d && # It's broken! git status # Because there are no more objects! ls .git/objects/pack ) Fix this by resolving symlinks and relative paths before comparing the alternate and object dir. This lets us clean up a number of issues noted in 37a95862c6 (alternates: re-allow relative paths from environment, 2016-11-07): - Now that we compare the real paths, duplicate detection is no longer foiled by relative paths. - Using strbuf_realpath() allows us to "normalize" paths that strbuf_normalize_path() can't, so we can stop silently ignoring errors when "normalizing" paths from the environment. - We now store an absolute path based on getcwd() (the "future direction" named in 37a95862c6), so chdir()-ing in the process no longer changes the directory pointed to by the alternate. This is a change in behavior, but a desirable one. Signed-off-by: Glen Choo <chooglen@google.com> Acked-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-11-18Merge branch 'tb/repack-expire-to'Taylor Blau
"git repack" learns to send cruft objects out of the way into packfiles outside the repository. * tb/repack-expire-to: builtin/repack.c: implement `--expire-to` for storing pruned objects builtin/repack.c: write cruft packs to arbitrary locations builtin/repack.c: pass "cruft_expiration" to `write_cruft_pack` builtin/repack.c: pass "out" to `prepare_pack_objects`
2022-10-30Merge branch 'jk/repack-tempfile-cleanup'Taylor Blau
The way "git repack" creared temporary files when it received a signal was prone to deadlocking, which has been corrected. * jk/repack-tempfile-cleanup: t7700: annotate cruft-pack failure with ok=sigpipe repack: drop remove_temporary_files() repack: use tempfiles for signal cleanup repack: expand error message for missing pack files repack: populate extension bits incrementally repack: convert "names" util bitfield to array
2022-10-28Merge branch 'tb/remove-unused-pack-bitmap'Junio C Hamano
When creating a multi-pack bitmap, remove per-pack bitmap files unconditionally as they will never be consulted. * tb/remove-unused-pack-bitmap: builtin/repack.c: remove redundant pack-based bitmaps
2022-10-24builtin/repack.c: implement `--expire-to` for storing pruned objectsTaylor Blau
When pruning objects with `--cruft`, `git repack` offers some flexibility when selecting the set of which objects are pruned via the `--cruft-expiration` option. This is useful for expiring objects which are older than the grace period, making races where to-be-pruned objects become reachable and then ancestors of freshly pushed objects, leaving the repository in a corrupt state after pruning substantially less likely [1]. But in practice, such races are impossible to avoid entirely, no matter how long the grace period is. To prevent this race, it is often advisable to temporarily put a repository into a read-only state. But in practice, this is not always practical, and so some middle ground would be nice. This patch introduces a new option, `--expire-to`, which teaches `git repack` to write an additional cruft pack containing just the objects which were pruned from the repository. The caller can specify a directory outside of the current repository as the destination for this second cruft pack. This makes it possible to prune objects from a repository, while still holding onto a supplemental copy of them outside of the original repository. Having this copy on-disk makes it substantially easier to recover objects when the aforementioned race is encountered. `--expire-to` is implemented in a somewhat convoluted manner, which is to take advantage of the fact that the first time `write_cruft_pack()` is called, it adds the name of the cruft pack to the `names` string list. That means the second time we call `write_cruft_pack()`, objects in the previously-written cruft pack will be excluded. As long as the caller ensures that no objects are expired during the second pass, this is sufficient to generate a cruft pack containing all objects which don't appear in any of the new packs written by `git repack`, including the cruft pack. In other words, all of the objects which are about to be pruned from the repository. It is important to note that the destination in `--expire-to` does not necessarily need to be a Git repository (though it can be) Notably, the expired packs do not contain all ancestors of expired objects. So if the source repository contains something like: <unreachable> / C1 --- C2 \ refs/heads/master where C2 is unreachable, but has a parent (C1) which is reachable, and C2 would be pruned, then the expiry pack will contain only C2, not C1. [1]: https://lore.kernel.org/git/20190319001829.GL29661@sigill.intra.peff.net/ Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-10-23t7700: annotate cruft-pack failure with ok=sigpipeJeff King
One of our tests intentionally causes the cruft-pack generation phase of repack to fail, in order to stimulate an exit from repack at the desired moment. It does so by feeding a bogus option argument to pack-objects. This is a simple and reliable way to get pack-objects to fail, but it has one downside: pack-objects will die before reading its stdin, which means the caller repack may racily get SIGPIPE writing to it. For the purposes of this test, that's OK. We are checking whether repack cleans up already-created .tmp files, and it will do so whether it exits or dies by signal (because the tempfile API hooks both). But we have to tell test_must_fail that either outcome is OK, or it complains about the signal. Arguably this is a workaround (compared to fixing repack), as repack dying to SIGPIPE means that it loses the opportunity to give a more detailed message. But we don't actually write such a message anyway; we rely on pack-objects to have written something useful to stderr, and it does. In either case (signal or exit), that is the main thing the user will see. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-10-21repack: drop remove_temporary_files()Jeff King
After we've successfully finished the repack, we call remove_temporary_files(), which looks for and removes any files matching ".tmp-$$-pack-*", where $$ is the pid of the current process. But this is pointless. If we make it this far in the process, we've already renamed these tempfiles into place, and there is nothing left to delete. Nor is there a point in trying to call it to clean up when we _aren't_ successful. It's not safe for using in a signal handler, and the previous commit already handed that job over to the tempfile API. It might seem like it would be useful to clean up stray .tmp files left by other invocations of git-repack. But it won't clean those files; it only matches ones with its pid, and leaves the rest. Fortunately, those are cleaned up naturally by successive calls to git-repack; we'll consider .tmp-*.pack the same as normal packfiles, so "repack -ad", etc, will roll up their contents and eventually delete them. The one case that could matter is if pack-objects generates an extension we don't know about, like ".tmp-pack-$$-$hash.some-new-ext". The current code will quietly delete such a file, while after this patch we'd leave it in place. In practice this doesn't happen, and would be indicative of a bug. Leaving the file as cruft is arguably a better behavior, as it means somebody is more likely to eventually notice and fix the bug. If we really wanted to be paranoid, we could scan for and warn about such files, but that seems like overkill. There's nothing to test with regard to the removal of this function. It was doing nothing, so the behavior should be the same. However, we can verify (and protect) our assumption that "repack -ad" will eventually remove stray files by adding a test for that. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-10-21repack: use tempfiles for signal cleanupJeff King
When git-repack exits due to a signal, it tries to clean up by calling its remove_temporary_files() function, which walks through the packs dir looking for ".tmp-$$-pack-*" files to delete (where "$$" is the pid of the current process). The biggest problem here is that remove_temporary_files() is not safe to call in a signal handler. It uses opendir(), which isn't on the POSIX async-signal-safe list. The details will be platform-specific, but a likely issue is that it needs to allocate memory; if we receive a signal while inside malloc(), etc, we'll conflict on the allocator lock and deadlock with ourselves. We can fix this by just cleaning up the files directly, without walking the directory. We already know the complete list of .tmp-* files that were generated, because we recorded them via populate_pack_exts(). When we find files there, we can use register_tempfile() to record the filenames. If we receive a signal, then the tempfile API will clean them up for us, and it's async-safe and pretty battle-tested. Note that this is slightly racier than the existing scheme. We don't record the filenames until pack-objects tells us the hash over stdout. So during the period between it generating the file and reporting the hash, we'd fail to clean up. However, that period is very small. During most of the pack generation process pack-objects is using its own internal tempfiles. It's only at the very end that it moves them into the names git-repack expects, and then it immediately reports the name to us. Given that cleanup like this is best effort (after all, we may get SIGKILL), this level of race is acceptable. When we register the tempfiles, we'll record them locally and use the result to call rename_tempfile(), rather than renaming by hand. This isn't strictly necessary, as once we've renamed the files they're gone, and the tempfile API's cleanup unlink() would simply become a pointless noop. But managing the lifetimes of the tempfile objects is the cleanest thing to do, and the tempfile pointers naturally fill the same role as the old booleans. This patch also fixes another small problem. We only hook signals, and don't set up an atexit handler. So if we see an error that causes us to die(), we'll leave the .tmp-* files in place. But since the tempfile API handles this for us, this is now fixed for free. The new test covers this by stimulating a failure of pack-objects when generating a cruft pack. Before this patch, the .tmp-* file for the main pack would have been left, but now we correctly clean it up. Two small subtleties on the implementation: - in the renaming loop, we can stop re-constructing fname_old; we only use it when we have a tempfile to rename, so we can just ask the tempfile for its path (which, barring bugs, should be identical) - when renaming fails, our error message mentions fname_old. But since a failed rename_tempfile() invalidates the tempfile struct, we'll lose access to that string. Instead, let's mention the destination filename, which is what most other callers do. Reported-by: Jan Pokorný <poki@fnusa.cz> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-10-17repack: don't remove .keep packs with `--pack-kept-objects`Taylor Blau
`git repack` supports a `--pack-kept-objects` flag which more or less translates to whether or not we pass `--honor-pack-keep` down to `git pack-objects` when assembling a new pack. This behavior has existed since ee34a2bead (repack: add `repack.packKeptObjects` config var, 2014-03-03). In that commit, the documentation was extended to say: [...] Note that we still do not delete `.keep` packs after `pack-objects` finishes. Unfortunately, this is not the case when `--pack-kept-objects` is combined with a `--geometric` repack. When doing a geometric repack, we include `.keep` packs when enumerating available packs only when `pack_kept_objects` is set. So this all works fine when `--no-pack-kept-objects` (or similar) is given. Kept packs are excluded from the geometric roll-up, so when we go to delete redundant packs (with `-d`), no `.keep` packs appear "below the split" in our geometric progression. But when `--pack-kept-objects` is given, things can go awry. Namely, when a kept pack is included in the list of packs tracked by the `pack_geometry` struct *and* part of the pack roll-up, we will delete the `.keep` pack when we shouldn't. Note that this *doesn't* result in object corruption, since the `.keep` pack's objects are still present in the new pack. But the `.keep` pack itself is removed, which violates our promise from back in ee34a2bead. But there's more. Because `repack` computes the geometric roll-up independently from selecting which packs belong in a MIDX (with `--write-midx`), this can lead to odd behavior. Consider when a `.keep` pack appears below the geometric split (ie., its objects will be part of the new pack we generate). We'll write a MIDX containing the new pack along with the existing `.keep` pack. But because the `.keep` pack appears below the geometric split line, we'll (incorrectly) try to remove it. While this doesn't corrupt the repository, it does cause us to remove the MIDX we just wrote, since removing that pack would invalidate the new MIDX. Funny enough, this behavior became far less noticeable after e4d0c11c04 (repack: respect kept objects with '--write-midx -b', 2021-12-20), which made `pack_kept_objects` be enabled by default only when we were writing a non-MIDX bitmap. But e4d0c11c04 didn't resolve this bug, it just made it harder to notice unless callers explicitly passed `--pack-kept-objects`. The solution is to avoid trying to remove `.keep` packs during `--geometric` repacks, even when they appear below the geometric split line, which is the approach this patch implements. Co-authored-by: Victoria Dye <vdye@github.com> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-10-17builtin/repack.c: remove redundant pack-based bitmapsTaylor Blau
When we write a MIDX bitmap after repacking, it is possible that the repository would be left in a state with both pack- and multi-pack reachability bitmaps. This can occur, for instance, if a pack that was kept (either by having a .keep file, or during a geometric repack in which it is not rolled up) has a bitmap file, and the repack wrote a multi-pack index and bitmap. When loading a reachability bitmap for the repository, the multi-pack one is always preferred, so the pack-based one is redundant. Let's remove it unconditionally, even if '-d' isn't passed, since there is no practical reason to keep both around. The patch below does just that. Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-25t7700: check post-condition in kept-pack testDerrick Stolee
The '--write-midx -b packs non-kept objects' test in t7700-repack.sh uses test_subcommand_inexact to check that 'git repack' properly adds the '--honor-pack-keep' flag to the 'git pack-objects' subcommand. However, the test_subcommand_inexact helper is more flexible than initially designed, and this instance is the only one that makes use of it: there are additional arguments between 'git pack-objects' and the '--honor-pack-keep' flag. In order to make test_subcommand_inexact more strict, we need to fix this instance. This test checks that 'git repack --write-midx -a -b -d' will create a new pack-file that does not contain the objects within the kept pack. This behavior is possible because of the multi-pack-index bitmap that will bitmap objects against multiple packs. Without --write-midx, the objects in the kept pack would be duplicated so the resulting pack is closed under reachability and bitmaps can be created against it. This is discussed in more detail in e4d0c11c0 (repack: respect kept objects with '--write-midx -b', 2021-12-20) which also introduced this instance of test_subcommand_inexact. To better verify the intended post-conditions while also removing this instance of test_subcommand_inexact, rewrite the test to check the list of packed objects in the kept pack and the list of the objects in the newly-repacked pack-file _other_ than the kept pack. These lists should be disjoint. Be sure to include a non-kept pack-file and loose objects to be extra careful that this is properly behaving with kept packs and not just avoiding repacking all pack-files. Co-authored-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-23Merge branch 'ps/repack-with-server-info'Junio C Hamano
"git repack" learned a new configuration to disable triggering of age-old "update-server-info" command, which is rarely useful these days. * ps/repack-with-server-info: repack: add config to skip updating server info repack: refactor to avoid double-negation of update-server-info
2022-03-14repack: add config to skip updating server infoPatrick Steinhardt
By default, git-repack(1) will update server info that is required by the dumb HTTP transport. This can be skipped by passing the `-n` flag, but what we're noticably missing is a config option to permanently disable updating this information. Add a new option "repack.updateServerInfo" which can be used to disable the logic. Most hosting providers have turned off the dumb HTTP protocol anyway, and on the client-side it woudln't typically be useful either. Giving a persistent way to disable this feature thus makes quite some sense to avoid wasting compute cycles and storage. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-14repack: refactor to avoid double-negation of update-server-infoPatrick Steinhardt
By default, git-repack(1) runs `update_server_info()` to generate info required for the dumb HTTP protocol. This can be disabled via the `-n` flag, which then sets the `no_update_server_info` flag. Further down the code this leads to some double-negation logic, which is about to become more confusing as we're about to add a new config which allows the user to permanently disable generation of the info. Refactor the code to avoid the double-negation and add some tests which verify that the flag continues to work as expected. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-16Merge branch 'tb/midx-bitmap-corruption-fix'Junio C Hamano
A bug that made multi-pack bitmap and the object order out-of-sync, making the .midx data corrupt, has been fixed. * tb/midx-bitmap-corruption-fix: pack-bitmap.c: gracefully fallback after opening pack/MIDX midx: read `RIDX` chunk when present t/lib-bitmap.sh: parameterize tests over reverse index source t5326: move tests to t/lib-bitmap.sh t5326: extract `test_rev_exists` t5326: drop unnecessary setup pack-revindex.c: instrument loading on-disk reverse index midx.c: make changing the preferred pack safe t5326: demonstrate bitmap corruption after permutation
2022-01-27midx: read `RIDX` chunk when presentTaylor Blau
When a MIDX contains the new `RIDX` chunk, ensure that the reverse index is read from it instead of the on-disk .rev file. Since we need to encode the object order in the MIDX itself for correctness reasons, there is no point in storing the same data again outside of the MIDX. So, this patch stops writing separate .rev files, and reads it out of the MIDX itself. This is possible to do with relatively little new code, since the format of the RIDX chunk is identical to the data in the .rev file. In other words, we can implement this by pointing the `revindex_data` field at the reverse index chunk of the MIDX instead of the .rev file without any other changes. Note that we have two knobs that are adjusted for the new tests: GIT_TEST_MIDX_WRITE_REV and GIT_TEST_MIDX_READ_RIDX. The former controls whether the MIDX .rev is written at all, and the latter controls whether we read the MIDX's RIDX chunk. Both are necessary to ensure that the test added at the beginning of this series continues to work. This is because we always need to write the RIDX chunk in the MIDX in order to change its checksum, but we want to make sure reading the existing .rev file still works (since the RIDX chunk takes precedence by default). Arguably this isn't a very interesting mode to test, because the precedence rules mean that we'll always read the RIDX chunk over the .rev file. But it makes it impossible for a user to induce corruption in their repository by adjusting the test knobs (since if we had an either/or knob they could stop writing the RIDX chunk, allowing them to tweak the MIDX's object order without changing its checksum). Signed-off-by: Taylor Blau <me@ttaylorr.com> Reviewed-by: Derrick Stolee <dstolee@microsoft.com> Reviewed-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-05Merge branch 'ds/repack-fixlets'Junio C Hamano
Two fixes around "git repack". * ds/repack-fixlets: repack: make '--quiet' disable progress repack: respect kept objects with '--write-midx -b'
2021-12-20repack: make '--quiet' disable progressDerrick Stolee
While testing some ideas in 'git repack', I ran it with '--quiet' and discovered that some progress output was still shown. Specifically, the output for writing the multi-pack-index showed the progress. The 'show_progress' variable in cmd_repack() is initialized with isatty(2) and is not modified at all by the '--quiet' flag. The '--quiet' flag modifies the po_args.quiet option which is translated into a '--quiet' flag for the 'git pack-objects' child process. However, 'show_progress' is used to directly send progress information to the multi-pack-index writing logic which does not use a child process. The fix here is to modify 'show_progress' to be false if po_opts.quiet is true, and isatty(2) otherwise. This new expectation simplifies a later condition that checks both. Update the documentation to make it clear that '-q' will disable all progress in addition to ensuring the 'git pack-objects' child process will receive the flag. Use 'test_terminal' to check that this works to get around the isatty(2) check. Helped-by: Jeff King <peff@peff.net> Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-20repack: respect kept objects with '--write-midx -b'Derrick Stolee
Historically, we needed a single packfile in order to have reachability bitmaps. This introduced logic that when 'git repack' had a '-b' option that we should stop sending the '--honor-pack-keep' option to the 'git pack-objects' child process, ensuring that we create a packfile containing all reachable objects. In the world of multi-pack-index bitmaps, we no longer need to repack all objects into a single pack to have valid bitmaps. Thus, we should continue sending the '--honor-pack-keep' flag to 'git pack-objects'. The fix is very simple: only disable the flag when writing bitmaps but also _not_ writing the multi-pack-index. This opens the door to new repacking strategies that might want to keep some historical set of objects in a stable pack-file while only repacking more recent objects. To test, create a new 'test_subcommand_inexact' helper that is more flexible than 'test_subcommand'. This allows us to look for the --honor-pack-keep flag without over-indexing on the exact set of arguments. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-13t6000-t9999: detect and signal failure within loopEric Sunshine
Failures within `for` and `while` loops can go unnoticed if not detected and signaled manually since the loop itself does not abort when a contained command fails, nor will a failure necessarily be detected when the loop finishes since the loop returns the exit code of the last command it ran on the final iteration, which may not be the command which failed. Therefore, detect and signal failures manually within loops using the idiom `|| return 1` (or `|| exit 1` within subshells). Signed-off-by: Eric Sunshine <sunshine@sunshineco.com> Reviewed-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-01builtin/repack.c: pass `--refs-snapshot` when writing bitmapsTaylor Blau
To prevent the race described in an earlier patch, generate and pass a reference snapshot to the multi-pack bitmap code, if we are writing one from `git repack`. This patch is mostly limited to creating a temporary file, and then calling for_each_ref(). Except we try to minimize duplicates, since doing so can drastically reduce the size in network-of-forks style repositories. In the kernel's fork network (the repository containing all objects from the kernel and all its forks), deduplicating the references drops the snapshot size from 934 MB to just 12 MB. But since we're handling duplicates in this way, we have to make sure that we preferred references (those listed in pack.preferBitmapTips) before non-preferred ones (to avoid recording an object which is pointed at by a preferred tip as non-preferred). We accomplish this by doing separate passes over the references: first visiting each prefix in pack.preferBitmapTips, and then over the rest of the references. Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-28builtin/repack.c: support writing a MIDX while repackingTaylor Blau
Teach `git repack` a new `--write-midx` option for callers that wish to persist a multi-pack index in their repository while repacking. There are two existing alternatives to this new flag, but they don't cover our particular use-case. These alternatives are: - Call 'git multi-pack-index write' after running 'git repack', or - Set 'GIT_TEST_MULTI_PACK_INDEX=1' in your environment when running 'git repack'. The former works, but introduces a gap in bitmap coverage between repacking and writing a new MIDX (since the repack may have deleted a pack included in the existing MIDX, invalidating it altogether). Setting the 'GIT_TEST_' environment variable is obviously unsupported. In fact, even if it were supported officially, it still wouldn't work, because it generates the MIDX *after* redundant packs have been dropped, leading to the same issue as above. Introduce a new option which eliminates this race by teaching `git repack` to generate the MIDX at the critical point: after the new packs have been written and moved into place, but before the redundant packs have been removed. This option is compatible with `git repack`'s '--bitmap' option (it changes the interpretation to be: "write a bitmap corresponding to the MIDX after one has been generated"). There is a little bit of additional noise in the patch below to avoid repeating ourselves when selecting which packs to delete. Instead of a single loop as before (where we iterate over 'existing_packs', decide if a pack is worth deleting, and if so, delete it), we have two loops (the first where we decide which ones are worth deleting, and the second where we actually do the deleting). This makes it so we have a single check we can make consistently when (1) telling the MIDX which packs we want to exclude, and (2) actually unlinking the redundant packs. There is also a tiny change to short-circuit the body of write_midx_included_packs() when no packs remain in the case of an empty repository. The MIDX code does not handle this, so avoid trying to generate a MIDX covering zero packs in the first place. Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-01t7700: update to work with MIDX bitmap test knobTaylor Blau
A number of these tests are focused only on pack-based bitmaps and need to be updated to disable 'GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP' where necessary. Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-04t7700: stop losing return codes of git commandsDenton Liu
In a pipe, only the return code of the last command is used. Thus, all other commands will have their return codes masked. Rewrite pipes so that there are no git commands upstream so that we will know if a command fails. Signed-off-by: Denton Liu <liu.denton@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-04t7700: make references to SHA-1 genericDenton Liu
Make the test more hash-agnostic by renaming variables from "sha1" to some variation of "oid" or "packid". Also, replace the regex, `[0-9a-f]\{40\}` with `$OID_REGEX`. A better name for "incrpackid" (incremental pack-id) might have been just "packid". However, later in the test suite, we have other uses of "packid". Although the scopes of these variables don't conflict, a future developer may think that commit_and_pack() and test_has_duplicate_object() are semantically related somehow since they share the same variable name. Give them distinct names so that it's clear these uses are unrelated. Signed-off-by: Denton Liu <liu.denton@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-04t7700: replace egrep with grepDenton Liu
The egrep expressions in this test suite were of the form `^$variable`. Although egrep works just fine, it's overkill since we're not using any extended regex. Replace egrep invocations with grep so that we aren't swatting flies with a sledgehammer. Signed-off-by: Denton Liu <liu.denton@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-04t7700: consolidate code into test_has_duplicate_object()Denton Liu
The code to test that objects were not duplicated from the packfile was duplicated many times. Extract the duplicated code into test_has_duplicate_object() and use that instead. Refactor the resulting extraction so that if the git command fails, the return code is not silently lost. Signed-off-by: Denton Liu <liu.denton@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>