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author | Patrick Steinhardt <ps@pks.im> | 2023-04-14 06:02:12 (GMT) |
---|---|---|
committer | Junio C Hamano <gitster@pobox.com> | 2023-04-14 17:27:52 (GMT) |
commit | d85cd1877777aa92c73868b9e86516d4be04b4a0 (patch) | |
tree | e24afebd53410563857c93b10634a5f80c0689e3 | |
parent | 932c16c04b5e41ee1c76d5640ec3ae67e1900c07 (diff) | |
download | git-d85cd1877777aa92c73868b9e86516d4be04b4a0.zip git-d85cd1877777aa92c73868b9e86516d4be04b4a0.tar.gz git-d85cd1877777aa92c73868b9e86516d4be04b4a0.tar.bz2 |
repack: disable writing bitmaps when doing a local repack
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>
-rw-r--r-- | builtin/repack.c | 12 | ||||
-rw-r--r-- | object-file.c | 6 | ||||
-rw-r--r-- | object-store.h | 1 | ||||
-rwxr-xr-x | t/t7700-repack.sh | 17 | ||||
-rwxr-xr-x | t/t7703-repack-geometric.sh | 27 |
5 files changed, 63 insertions, 0 deletions
diff --git a/builtin/repack.c b/builtin/repack.c index 165fe1b..c26f067 100644 --- a/builtin/repack.c +++ b/builtin/repack.c @@ -885,6 +885,18 @@ int cmd_repack(int argc, const char **argv, const char *prefix) if (write_bitmaps && !(pack_everything & ALL_INTO_ONE) && !write_midx) die(_(incremental_bitmap_conflict_error)); + if (write_bitmaps && po_args.local && has_alt_odb(the_repository)) { + /* + * When asked to do a local repack, but we have + * packfiles that are inherited from an alternate, then + * we cannot guarantee that the multi-pack-index would + * have full coverage of all objects. We thus disable + * writing bitmaps in that case. + */ + warning(_("disabling bitmap writing, as some objects are not being packed")); + write_bitmaps = 0; + } + if (write_midx && write_bitmaps) { struct strbuf path = STRBUF_INIT; diff --git a/object-file.c b/object-file.c index 939865c..a6574b2 100644 --- a/object-file.c +++ b/object-file.c @@ -944,6 +944,12 @@ void prepare_alt_odb(struct repository *r) r->objects->loaded_alternates = 1; } +int has_alt_odb(struct repository *r) +{ + prepare_alt_odb(r); + return !!r->objects->odb->next; +} + /* Returns 1 if we have successfully freshened the file, 0 otherwise. */ static int freshen_file(const char *fn) { diff --git a/object-store.h b/object-store.h index 1a713d8..8ba010a 100644 --- a/object-store.h +++ b/object-store.h @@ -56,6 +56,7 @@ KHASH_INIT(odb_path_map, const char * /* key: odb_path */, struct object_directory *, 1, fspathhash, fspatheq) void prepare_alt_odb(struct repository *r); +int has_alt_odb(struct repository *r); char *compute_alternate_path(const char *path, struct strbuf *err); struct object_directory *find_odb(struct repository *r, const char *obj_dir); typedef int alt_odb_fn(struct object_directory *, void *); diff --git a/t/t7700-repack.sh b/t/t7700-repack.sh index 4aabe98..faa739e 100755 --- a/t/t7700-repack.sh +++ b/t/t7700-repack.sh @@ -106,6 +106,23 @@ test_expect_success SYMLINKS '--local keeps packs when alternate is objectdir ' test_cmp expect actual ' +test_expect_success '--local disables writing bitmaps when connected to alternate ODB' ' + test_when_finished "rm -rf shared member" && + + git init shared && + git clone --shared shared member && + ( + cd member && + test_commit "object" && + GIT_TEST_MULTI_PACK_INDEX=0 git repack -Adl --write-bitmap-index 2>err && + cat >expect <<-EOF && + warning: disabling bitmap writing, as some objects are not being packed + EOF + test_cmp expect err && + test_path_is_missing .git/objects/pack-*.bitmap + ) +' + test_expect_success 'packed obs in alt ODB are repacked even when local repo is packless' ' mkdir alt_objects/pack && mv .git/objects/pack/* alt_objects/pack && diff --git a/t/t7703-repack-geometric.sh b/t/t7703-repack-geometric.sh index be8fe78..00f28fb 100755 --- a/t/t7703-repack-geometric.sh +++ b/t/t7703-repack-geometric.sh @@ -418,4 +418,31 @@ test_expect_success '--geometric -l with non-intact geometric sequence across OD test_cmp expected-objects actual-objects ' +test_expect_success '--geometric -l disables writing bitmaps with non-local packfiles' ' + test_when_finished "rm -fr shared member" && + + git init shared && + test_commit_bulk -C shared --start=1 1 && + + git clone --shared shared member && + test_commit_bulk -C member --start=2 1 && + + # When performing a geometric repack with `-l` while connected to an + # alternate object database that has a packfile we do not have full + # coverage of objects. As a result, we expect that writing the bitmap + # will be disabled. + git -C member repack -l --geometric=2 --write-midx --write-bitmap-index 2>err && + cat >expect <<-EOF && + warning: disabling bitmap writing, as some objects are not being packed + EOF + test_cmp expect err && + test_path_is_missing member/.git/objects/pack/multi-pack-index-*.bitmap && + + # On the other hand, when we repack without `-l`, we should see that + # the bitmap gets created. + git -C member repack --geometric=2 --write-midx --write-bitmap-index 2>err && + test_must_be_empty err && + test_path_is_file member/.git/objects/pack/multi-pack-index-*.bitmap +' + test_done |