This allows us to replace includes of cache.h with includes of the much
smaller alloc.h in many places. It does mean that we also need to add
includes of alloc.h in a number of C files.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In cmd_repack() when we hit an error, replace "return ret" with "goto
cleanup" to ensure we free the necessary data structures.
Helped-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Various leak fixes.
* ab/various-leak-fixes:
built-ins: use free() not UNLEAK() if trivial, rm dead code
revert: fix parse_options_concat() leak
cherry-pick: free "struct replay_opts" members
rebase: don't leak on "--abort"
connected.c: free the "struct packed_git"
sequencer.c: fix "opts->strategy" leak in read_strategy_opts()
ls-files: fix a --with-tree memory leak
revision API: call graph_clear() in release_revisions()
unpack-file: fix ancient leak in create_temp_file()
built-ins & libs & helpers: add/move destructors, fix leaks
dir.c: free "ident" and "exclude_per_dir" in "struct untracked_cache"
read-cache.c: clear and free "sparse_checkout_patterns"
commit: discard partial cache before (re-)reading it
{reset,merge}: call discard_index() before returning
tests: mark tests as passing with SANITIZE=leak
Fix various leaks in built-ins, libraries and a test helper here we
were missing a call to strbuf_release(), string_list_clear() etc, or
were calling them after a potential "return".
Comments on individual changes:
- builtin/checkout.c: Fix a memory leak that was introduced in [1]. A
sibling leak introduced in [2] was recently fixed in [3]. As with [3]
we should be using the wt_status_state_free_buffers() API introduced
in [4].
- builtin/repack.c: Fix a leak that's been here since this use of
"strbuf_release()" was added in a1bbc6c017 (repack: rewrite the shell
script in C, 2013-09-15). We don't use the variable for anything
except this loop, so we can instead free it right afterwards.
- builtin/rev-parse: Fix a leak that's been here since this code was
added in 21d4783538 (Add a parseopt mode to git-rev-parse to bring
parse-options to shell scripts., 2007-11-04).
- builtin/stash.c: Fix a couple of leaks that have been here since
this code was added in d4788af875 (stash: convert create to builtin,
2019-02-25), we strbuf_release()'d only some of the "struct strbuf" we
allocated earlier in the function, let's release all of them.
- ref-filter.c: Fix a leak in 482c119186 (gpg-interface: improve
interface for parsing tags, 2021-02-11), we don't use the "payload"
variable that we ask parse_signature() to populate for us, so let's
free it.
- t/helper/test-fake-ssh.c: Fix a leak that's been here since this
code was added in 3064d5a38c (mingw: fix t5601-clone.sh,
2016-01-27). Let's free the "struct strbuf" as soon as we don't need
it anymore.
1. c45f0f525d (switch: reject if some operation is in progress,
2019-03-29)
2. 2708ce62d2 (branch: sort detached HEAD based on a flag,
2021-01-07)
3. abcac2e19f (ref-filter.c: fix a leak in get_head_description,
2022-09-25)
4. 962dd7ebc3 (wt-status: introduce wt_status_state_free_buffers(),
2020-09-27).
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
"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`
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
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
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>
In the following commit, a new write_cruft_pack() caller will be added
which wants to write a cruft pack to an arbitrary location. Prepare for
this by adding a parameter which controls the destination of the cruft
pack.
For now, provide "packtmp" so that this commit does not change any
behavior.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
`builtin/repack.c`'s `write_cruft_pack()` is used to generate the cruft
pack when `--cruft` is supplied. It uses a static variable
"cruft_expiration" which is filled in by option parsing.
A future patch will add an `--expire-to` option which allows `git
repack` to write a cruft pack containing the pruned objects out to a
separate repository. In order to implement this functionality, some
callers will have to pass a value for `cruft_expiration` different than
the one filled out by option parsing.
Prepare for this by teaching `write_cruft_pack` to take a
"cruft_expiration" parameter, instead of reading a single static
variable.
The (sole) existing caller of `write_cruft_pack()` will pass the value
for "cruft_expiration" filled in by option parsing, retaining existing
behavior. This means that we can make the variable local to
`cmd_repack()`, and eliminate the static declaration.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
`builtin/repack.c`'s `prepare_pack_objects()` is used to prepare a set
of arguments to a `pack-objects` process which will generate a desired
pack.
A future patch will add an `--expire-to` option which allows `git
repack` to write a cruft pack containing the pruned objects out to a
separate repository. Prepare for this by teaching that function to write
packs to an arbitrary location specified by the caller.
All existing callers of `prepare_pack_objects()` will pass `packtmp` for
`out`, retaining the existing behavior.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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-$$-$hash.some-new-ext". The current
code will quietly delete such a file, while after this patch we'd leave
it in place. In practice this doesn't happen, and would be indicative of
a bug. Leaving the file as cruft is arguably a better behavior, as it
means somebody is more likely to eventually notice and fix the bug. If
we really wanted to be paranoid, we could scan for and warn about such
files, but that seems like overkill.
There's nothing to test with regard to the removal of this function. It
was doing nothing, so the behavior should be the same. However, we can
verify (and protect) our assumption that "repack -ad" will eventually
remove stray files by adding a test for that.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When git-repack exits due to a signal, it tries to clean up by calling
its remove_temporary_files() function, which walks through the packs dir
looking for ".tmp-$$-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>
If pack-objects tells us it generated pack $hash, we expect to find
.tmp-$$-pack-$hash.pack, .idx, .rev, and so on. Some of these files are
optional, but others are not. For the required ones, we'll bail with an
error if any of them is missing.
The error message is just "missing required file", which is a bit vague.
We should be more clear that it is not the user's fault, but rather that
the sub-pgoram we called is not operating as expected. In practice,
nobody should ever see this message, as it would generally only be
caused by a bug in Git.
It probably doesn't make sense to convert this to a BUG(), though, as
there are other (unlikely) possibilities, such as somebody else racily
deleting the files, filesystem errors causing stat() to fail, and so on.
A nice side effect here is that we stop relying on fname_old in this
code path, which will let us deal with it only in the first part of the
conditional.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
After generating the main pack and then any additional cruft packs, we
iterate over the "names" list (which contains hashes of packs generated
by pack-objects), and call populate_pack_exts() for each.
There's one small problem with this. In repack_promisor_objects(), we
may add entries to "names" and call populate_pack_exts() for them.
Calling it again is mostly just wasteful, as we'll stat() the filename
with each possible extension, get the same result, and just overwrite
our bits.
So we could drop the call there, and leave the final loop to populate
all of the bits. But instead, this patch does the reverse: drops the
final loop, and teaches the other two sites to populate the bits as they
add entries.
This makes the code easier to reason about, as you never have to worry
about when the util field is valid; it is always valid for each entry.
It also serves my ulterior purpose: recording the generated filenames as
soon as possible will make it easier for a future patch to use them for
cleaning up from a failed operation.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We keep a string_list "names" containing the hashes of packs generated
on our behalf by pack-objects. The util field of each item is treated as
a bitfield that tells us which extensions (.pack, .idx, .rev, etc) are
present for each name.
Let's switch this to allocating a real array. That will give us room in
a future patch to store more data than just a single bit per extension.
And it makes the code a little easier to read, as we avoid casting back
and forth between uintptr_t and a void pointer.
Since the only thing we're storing is an array, we could just allocate
it directly. But instead I've put it into a named struct here. That
further increases readability around the casts, and in particular helps
differentiate us from other string_lists in the same file which use
their util field differently. E.g., the existing_*_packs lists still do
bit-twiddling, but their bits have different meaning than the ones in
"names". This makes it hard to grep around the code to see how the util
fields are used; now you can look for "generated_pack_data".
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
`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>
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>
As reported in [1] the "UNUSED(var)" macro introduced in
2174b8c75d (Merge branch 'jk/unused-annotation' into next,
2022-08-24) breaks coccinelle's parsing of our sources in files where
it occurs.
Let's instead partially go with the approach suggested in [2] of
making this not take an argument. As noted in [1] "coccinelle" will
ignore such tokens in argument lists that it doesn't know about, and
it's less of a surprise to syntax highlighters.
This undoes the "help us notice when a parameter marked as unused is
actually use" part of 9b24034754 (git-compat-util: add UNUSED macro,
2022-08-19), a subsequent commit will further tweak the macro to
implement a replacement for that functionality.
1. https://lore.kernel.org/git/220825.86ilmg4mil.gmgdl@evledraar.gmail.com/
2. https://lore.kernel.org/git/220819.868rnk54ju.gmgdl@evledraar.gmail.com/
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Functions used with for_each_ref(), etc, need to conform to the
each_ref_fn interface. But most of them don't need every parameter;
let's annotate the unused ones to quiet -Wunused-parameter.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Generalize the newly added "unused.cocci" rule to find more than just
"struct strbuf", let's have it find the same unused patterns for
"struct string_list", as well as other code that uses
similar-looking *_{release,clear,free}() and {release,clear,free}_*()
functions.
We're intentionally loose in accepting e.g. a "strbuf_init(&sb)"
followed by a "string_list_clear(&sb, 0)". It's assumed that the
compiler will catch any such invalid code, i.e. that our
constructors/destructors don't take a "void *".
See [1] for example of code that would be covered by the
"get_worktrees()" part of this rule. We'd still need work that the
series is based on (we were passing "worktrees" to a function), but
could now do the change in [1] automatically.
1. https://lore.kernel.org/git/Yq6eJFUPPTv%2Fzc0o@coredump.intra.peff.net/
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Some config variables are combinations of multiple words, and we
typically write them in camelCase forms in manpage and translatable
strings. It's not easy to find mismatches for these camelCase config
variables during code reviews, but occasionally they are identified
during localization translations.
To check for mismatched config variables, I introduced a new feature
in the helper program for localization[^1]. The following mismatched
config variables have been identified by running the helper program,
such as "git-po-helper check-pot".
Lowercase in manpage should use camelCase:
* Documentation/config/http.txt: http.pinnedpubkey
Lowercase in translable strings should use camelCase:
* builtin/fast-import.c: pack.indexversion
* builtin/gc.c: gc.logexpiry
* builtin/index-pack.c: pack.indexversion
* builtin/pack-objects.c: pack.indexversion
* builtin/repack.c: pack.writebitmaps
* commit.c: i18n.commitencoding
* gpg-interface.c: user.signingkey
* http.c: http.postbuffer
* submodule-config.c: submodule.fetchjobs
Mismatched camelCases, choose the former:
* Documentation/config/transfer.txt: transfer.credentialsInUrl
remote.c: transfer.credentialsInURL
[^1]: https://github.com/git-l10n/git-po-helper
Signed-off-by: Jiang Xin <zhiyou.jx@alibaba-inc.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A mechanism to pack unreachable objects into a "cruft pack",
instead of ejecting them into loose form to be reclaimed later, has
been introduced.
* tb/cruft-packs:
sha1-file.c: don't freshen cruft packs
builtin/gc.c: conditionally avoid pruning objects via loose
builtin/repack.c: add cruft packs to MIDX during geometric repack
builtin/repack.c: use named flags for existing_packs
builtin/repack.c: allow configuring cruft pack generation
builtin/repack.c: support generating a cruft pack
builtin/pack-objects.c: --cruft with expiration
reachable: report precise timestamps from objects in cruft packs
reachable: add options to add_unseen_recent_objects_to_traversal
builtin/pack-objects.c: --cruft without expiration
builtin/pack-objects.c: return from create_object_entry()
t/helper: add 'pack-mtimes' test-tool
pack-mtimes: support writing pack .mtimes files
chunk-format.h: extract oid_version()
pack-write: pass 'struct packing_data' to 'stage_tmp_packfiles'
pack-mtimes: support reading .mtimes files
Documentation/technical: add cruft-packs.txt
When using cruft packs, the following race can occur when a geometric
repack that writes a MIDX bitmap takes place afterwords:
- First, create an unreachable object and do an all-into-one cruft
repack which stores that object in the repository's cruft pack.
- Then make that object reachable.
- Finally, do a geometric repack and write a MIDX bitmap.
Assuming that we are sufficiently unlucky as to select a commit from the
MIDX which reaches that object for bitmapping, then the `git
multi-pack-index` process will complain that that object is missing.
The reason is because we don't include cruft packs in the MIDX when
doing a geometric repack. Since the "make that object reachable" doesn't
necessarily mean that we'll create a new copy of that object in one of
the packs that will get rolled up as part of a geometric repack, it's
possible that the MIDX won't see any copies of that now-reachable
object.
Of course, it's desirable to avoid including cruft packs in the MIDX
because it causes the MIDX to store a bunch of objects which are likely
to get thrown away. But excluding that pack does open us up to the above
race.
This patch demonstrates the bug, and resolves it by including cruft
packs in the MIDX even when doing a geometric repack.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We use the `util` pointer for items in the `existing_packs` string list
to indicate which packs are going to be deleted. Since that has so far
been the only use of that `util` pointer, we just set it to 0 or 1.
But we're going to add an additional state to this field in the next
patch, so prepare for that by adding a #define for the first bit so we
can more expressively inspect the flags state.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In servers which set the pack.window configuration to a large value, we
can wind up spending quite a lot of time finding new bases when breaking
delta chains between reachable and unreachable objects while generating
a cruft pack.
Introduce a handful of `repack.cruft*` configuration variables to
control the parameters used by pack-objects when generating a cruft
pack.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Expose a way to split the contents of a repository into a main and cruft
pack when doing an all-into-one repack with `git repack --cruft -d`, and
a complementary configuration variable.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
To store the individual mtimes of objects in a cruft pack, introduce a
new `.mtimes` format that can optionally accompany a single pack in the
repository.
The format is defined in Documentation/technical/pack-format.txt, and
stores a 4-byte network order timestamp for each object in name (index)
order.
This patch prepares for cruft packs by defining the `.mtimes` format,
and introducing a basic API that callers can use to read out individual
mtimes.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The previous patch demonstrates a scenario where the list of packs
written by `pack-objects` (and stored in the `names` string_list) is
out-of-order, and can thus cause us to delete packs we shouldn't.
This patch resolves that bug by ensuring that `names` is sorted in all
cases, not just when
delete_redundant && pack_everything & ALL_INTO_ONE
is true.
Because we did sort `names` in that case (which, prior to `--geometric`
repacks, was the only time we would actually delete packs, this is only
a bug for `--geometric` repacks.
It would be sufficient to only sort `names` when `delete_redundant` is
set to a non-zero value. But sorting a small list of strings is cheap,
and it is defensive against future calls to `string_list_has_string()`
on this list.
Co-discovered-by: Victoria Dye <vdye@github.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Update 'repack' to ignore packs named on the command line with the
'--keep-pack' option. Specifically, modify 'init_pack_geometry()' to treat
command line-kept packs the same way it treats packs with an on-disk '.keep'
file (that is, skip the pack and do not include it in the 'geometry'
structure).
Without this handling, a '--keep-pack' pack would be included in the
'geometry' structure. If the pack is *before* the geometry split line (with
at least one other pack and/or loose objects present), 'repack' assumes the
pack's contents are "rolled up" into another pack via 'pack-objects'.
However, because the internally-invoked 'pack-objects' properly excludes
'--keep-pack' objects, any new pack it creates will not contain the kept
objects. Finally, 'repack' deletes the '--keep-pack' as "redundant" (since
it assumes 'pack-objects' created a new pack with its contents), resulting
in possible object loss and repository corruption.
Add a test ensuring that '--keep-pack' packs are now appropriately handled.
Co-authored-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Victoria Dye <vdye@github.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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>
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>
Similar message templates have been consolidated so that
translators need to work on fewer number of messages.
* ja/i18n-similar-messages:
i18n: turn even more messages into "cannot be used together" ones
i18n: ref-filter: factorize "%(foo) atom used without %(bar) atom"
i18n: factorize "--foo outside a repository"
i18n: refactor "unrecognized %(foo) argument" strings
i18n: factorize "no directory given for --foo"
i18n: factorize "--foo requires --bar" and the like
i18n: tag.c factorize i18n strings
i18n: standardize "cannot open" and "cannot read"
i18n: turn "options are incompatible" into "cannot be used together"
i18n: refactor "%s, %s and %s are mutually exclusive"
i18n: refactor "foo and bar are mutually exclusive"
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>
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>
On platforms where ulong is shorter than size_t, code paths that
shifted 1 or 1U to the left lacked the necessary cast to size_t,
which have been corrected.
* po/size-t-for-vs:
object-file.c: LLP64 compatibility, upcast unity for left shift
diffcore-delta.c: LLP64 compatibility, upcast unity for left shift
repack.c: LLP64 compatibility, upcast unity for left shift
Visual Studio reports C4334 "was 64-bit shift intended" warning
because of size mismatch.
Promote unity to the matching type to fit with the `&` operator.
Signed-off-by: Philip Oakley <philipoakley@iee.email>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
`git repack` invokes a handful of child processes: one to write the
actual pack, and optionally ones to repack promisor objects and update
the MIDX.
Most of these are freed automatically by calling `start_command()` (which
invokes it on error) and `finish_command()` which calls it
automatically.
But repack_promisor_objects() can initialize a child_process, populate
its array of arguments, and then return from the function before even
calling start_command().
Make sure that the prepared list of arguments is freed by calling
child_process_clear() ourselves to avoid leaking memory along this path.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git repack" has been taught to generate multi-pack reachability
bitmaps.
* tb/repack-write-midx:
test-read-midx: fix leak of bitmap_index struct
builtin/repack.c: pass `--refs-snapshot` when writing bitmaps
builtin/repack.c: make largest pack preferred
builtin/repack.c: support writing a MIDX while repacking
builtin/repack.c: extract showing progress to a variable
builtin/repack.c: rename variables that deal with non-kept packs
builtin/repack.c: keep track of existing packs unconditionally
midx: preliminary support for `--refs-snapshot`
builtin/multi-pack-index.c: support `--stdin-packs` mode
midx: expose `write_midx_file_only()` publicly
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>
When repacking into a geometric series and writing a multi-pack bitmap,
it is beneficial to have the largest resulting pack be the preferred
object source in the bitmap's MIDX, since selecting the large packs can
lead to fewer broken delta chains and better compression.
Teach 'git repack' to identify this pack and pass it to the MIDX write
machinery in order to mark it as preferred.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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>
We only ask whether stderr is a tty before calling
'prune_packed_objects()', but the subsequent patch will add another use.
Extract this check into a variable so that both can use it without
having to call 'isatty()' twice.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The new variable `existing_kept_packs` (and corresponding parameter
`fname_kept_list`) added by the previous patch make it seem like
`existing_packs` and `fname_list` are each subsets of the other two
respectively.
In reality, each pair is disjoint: one stores the packs without .keep
files, and the other stores the packs with .keep files. Rename each to
more clearly reflect this.
Suggested-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In order to be able to write a multi-pack index during repacking, `git
repack` must keep track of which packs it wants to write into the MIDX.
This set is the union of existing packs which will not be deleted,
new pack(s) generated as a result of the repack, and .keep packs.
Prior to this patch, `git repack` populated the list of existing packs
only when repacking all-into-one (i.e., with `-A` or `-a`), but we will
soon need to know this list when repacking when writing a MIDX without
a-i-o.
Populate the list of existing packs unconditionally, and guard removing
packs from that list only when repacking a-i-o.
Additionally, keep track of filenames of kept packs separately, since
this, too, will be used in an upcoming patch.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
To figure out which commits we can write a bitmap for, the multi-pack
index/bitmap code does a reachability traversal, marking any commit
which can be found in the MIDX as eligible to receive a bitmap.
This approach will cause a problem when multi-pack bitmaps are able to
be generated from `git repack`, since the reference tips can change
during the repack. Even though we ignore commits that don't exist in
the MIDX (when doing a scan of the ref tips), it's possible that a
commit in the MIDX reaches something that isn't.
This can happen when a multi-pack index contains some pack which refers
to loose objects (e.g., if a pack was pushed after starting the repack
but before generating the MIDX which depends on an object which is
stored as loose in the repository, and by definition isn't included in
the multi-pack index).
By taking a snapshot of the references before we start repacking, we can
close that race window. In the above scenario (where we have a packed
object pointing at a loose one), we'll either (a) take a snapshot of the
references before seeing the packed one, or (b) take it after, at which
point we can guarantee that the loose object will be packed and included
in the MIDX.
This patch does just that. It writes a temporary "reference snapshot",
which is a list of OIDs that are at the ref tips before writing a
multi-pack bitmap. References that are "preferred" (i.e,. are a suffix
of at least one value of the 'pack.preferBitmapTips' configuration) are
marked with a special '+'.
The format is simple: one line per commit at each tip, with an optional
'+' at the beginning (for preferred references, as described above).
When provided, the reference snapshot is used to drive bitmap selection
instead of the MIDX code doing its own traversal. When it isn't
provided, the usual traversal takes place instead.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Now that GIT_REF_PARANOIA is the default, we don't need to selectively
enable it for destructive operations. In fact, it's harmful to do so,
because it overrides any GIT_REF_PARANOIA=0 setting that the user may
have provided (because they're trying to work around some corruption).
With these uses gone, we can further clean up the ref_paranoia global,
and make it a static variable inside the refs code.
Signed-off-by: Jeff King <peff@peff.net>
Reviewed-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The order in which various files that make up a single (conceptual)
packfile has been reevaluated and straightened up. This matters in
correctness, as an incomplete set of files must not be shown to a
running Git.
* tb/pack-finalize-ordering:
pack-objects: rename .idx files into place after .bitmap files
pack-write: split up finish_tmp_packfile() function
builtin/index-pack.c: move `.idx` files into place last
index-pack: refactor renaming in final()
builtin/repack.c: move `.idx` files into place last
pack-write.c: rename `.idx` files after `*.rev`
pack-write: refactor renaming in finish_tmp_packfile()
bulk-checkin.c: store checksum directly
pack.h: line-wrap the definition of finish_tmp_packfile()
In a similar spirit as the previous patch, fix the identical problem
from `git repack` (which invokes `pack-objects` with a temporary
location for output, and then moves the files into their final locations
itself).
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce a new 'GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP' environment
variable to also write a multi-pack bitmap when
'GIT_TEST_MULTI_PACK_INDEX' is set.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When `git repack -A -d` is run in a partial clone, `pack-objects`
is invoked twice: once to repack all promisor objects, and once to
repack all non-promisor objects. The latter `pack-objects` invocation
is with --exclude-promisor-objects and --unpack-unreachable, which
loosens all objects unused during this invocation. Unfortunately,
this includes promisor objects.
Because the -d argument to `git repack` subsequently deletes all loose
objects also in packs, these just-loosened promisor objects will be
immediately deleted. However, this extra disk churn is unnecessary in
the first place. For example, in a newly-cloned partial repo that
filters all blob objects (e.g. `--filter=blob:none`), `repack` ends up
unpacking all trees and commits into the filesystem because every
object, in this particular case, is a promisor object. Depending on
the repo size, this increases the disk usage considerably: In my copy
of the linux.git, the object directory peaked 26GB of more disk usage.
In order to avoid this extra disk churn, pass the names of the promisor
packfiles as --keep-pack arguments to the second invocation of
`pack-objects`. This informs `pack-objects` that the promisor objects
are already in a safe packfile and, therefore, do not need to be
loosened.
For testing, we need to validate whether any object was loosened.
However, the "evidence" (loosened objects) is deleted during the
process which prevents us from inspecting the object directory.
Instead, let's teach `pack-objects` to count loosened objects and
emit via trace2 thus allowing inspecting the debug events after the
process is finished. This new event is used on the added regression
test.
Lastly, add a new perf test to evaluate the performance impact
made by this changes (tested on git.git):
Test HEAD^ HEAD
----------------------------------------------------------
5600.3: gc 134.38(41.93+90.95) 7.80(6.72+1.35) -94.2%
For a bigger repository, such as linux.git, the improvement is
even bigger:
Test HEAD^ HEAD
-------------------------------------------------------------------
5600.3: gc 6833.00(918.07+3162.74) 268.79(227.02+39.18) -96.1%
These improvements are particular big because every object in the
newly-cloned partial repository is a promisor object.
Reported-by: SZEDER Gábor <szeder.dev@gmail.com>
Helped-by: Jeff King <peff@peff.net>
Helped-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Rafael Silva <rafaeloliveira.cs@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
An on-disk reverse-index to map the in-pack location of an object
back to its object name across multiple packfiles is introduced.
* tb/reverse-midx:
midx.c: improve cache locality in midx_pack_order_cmp()
pack-revindex: write multi-pack reverse indexes
pack-write.c: extract 'write_rev_file_order'
pack-revindex: read multi-pack reverse indexes
Documentation/technical: describe multi-pack reverse indexes
midx: make some functions non-static
midx: keep track of the checksum
midx: don't free midx_name early
midx: allow marking a pack as preferred
t/helper/test-read-midx.c: add '--show-objects'
builtin/multi-pack-index.c: display usage on unrecognized command
builtin/multi-pack-index.c: don't enter bogus cmd_mode
builtin/multi-pack-index.c: split sub-commands
builtin/multi-pack-index.c: define common usage with a macro
builtin/multi-pack-index.c: don't handle 'progress' separately
builtin/multi-pack-index.c: inline 'flags' with options
When multiple packs in the multi-pack index contain the same object, the
MIDX machinery must make a choice about which pack it associates with
that object. Prior to this patch, the lowest-ordered[1] pack was always
selected.
Pack selection for duplicate objects is relatively unimportant today,
but it will become important for multi-pack bitmaps. This is because we
can only invoke the pack-reuse mechanism when all of the bits for reused
objects come from the reuse pack (in order to ensure that all reused
deltas can find their base objects in the same pack).
To encourage the pack selection process to prefer one pack over another
(the pack to be preferred is the one a caller would like to later use as
a reuse pack), introduce the concept of a "preferred pack". When
provided, the MIDX code will always prefer an object found in a
preferred pack over any other.
No format changes are required to store the preferred pack, since it
will be able to be inferred with a corresponding MIDX bitmap, by looking
up the pack associated with the object in the first bit position (this
ordering is described in detail in a subsequent commit).
[1]: the ordering is specified by MIDX internals; for our purposes we
can consider the "lowest ordered" pack to be "the one with the
most-recent mtime.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The comment in this block is meant to indicate that passing '--all',
'--reflog', and so on aren't necessary when repacking with the
'--geometric' option.
But, it has two problems: first, it is factually incorrect ('--all' is
*not* incompatible with '--stdin-packs' as the comment suggests);
second, it is quite focused on the geometric case for a block that is
guarding against it.
Reword this comment to address both issues.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are a number of places in the geometric repack code where we
multiply the number of objects in a pack by another unsigned value. We
trust that the number of objects in a pack is always representable by a
uint32_t, but we don't necessarily trust that that number can be
multiplied without overflow.
Sprinkle some unsigned_add_overflows() and unsigned_mult_overflows() in
split_pack_geometry() to check that we never overflow any unsigned types
when adding or multiplying them.
Arguably these checks are a little too conservative, and certainly they
do not help the readability of this function. But they are serving a
useful purpose, so I think they are worthwhile overall.
Suggested-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
To determine the where to place the split when repacking with the
'--geometric' option, split_pack_geometry() assigns the "split" variable
and then decrements it in a loop.
It would be equivalent (and more readable) to assign the split to the
loop position after exiting the loop, so do that instead.
Suggested-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In 0fabafd0b9 (builtin/repack.c: add '--geometric' option, 2021-02-22),
the 'git repack --geometric' code aborts early when there is zero or one
pack.
When there are no packs, this code does the right thing by placing the
split at "0". But when there is exactly one pack, the split is placed at
"1", which means that "git repack --geometric" (with any factor)
repacks all of the objects in a single pack.
This is wasteful, and the remaining code in split_pack_geometry() does
the right thing (not repacking the objects in a single pack) even when
only one pack is present.
Loosen the guard to only stop when there aren't any packs, and let the
rest of the code do the right thing. Add a test to ensure that this is
the case.
Noticed-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Often it is useful to both:
- have relatively few packfiles in a repository, and
- avoid having so few packfiles in a repository that we repack its
entire contents regularly
This patch implements a '--geometric=<n>' option in 'git repack'. This
allows the caller to specify that they would like each pack to be at
least a factor times as large as the previous largest pack (by object
count).
Concretely, say that a repository has 'n' packfiles, labeled P1, P2,
..., up to Pn. Each packfile has an object count equal to 'objects(Pn)'.
With a geometric factor of 'r', it should be that:
objects(Pi) > r*objects(P(i-1))
for all i in [1, n], where the packs are sorted by
objects(P1) <= objects(P2) <= ... <= objects(Pn).
Since finding a true optimal repacking is NP-hard, we approximate it
along two directions:
1. We assume that there is a cutoff of packs _before starting the
repack_ where everything to the right of that cut-off already forms
a geometric progression (or no cutoff exists and everything must be
repacked).
2. We assume that everything smaller than the cutoff count must be
repacked. This forms our base assumption, but it can also cause
even the "heavy" packs to get repacked, for e.g., if we have 6
packs containing the following number of objects:
1, 1, 1, 2, 4, 32
then we would place the cutoff between '1, 1' and '1, 2, 4, 32',
rolling up the first two packs into a pack with 2 objects. That
breaks our progression and leaves us:
2, 1, 2, 4, 32
^
(where the '^' indicates the position of our split). To restore a
progression, we move the split forward (towards larger packs)
joining each pack into our new pack until a geometric progression
is restored. Here, that looks like:
2, 1, 2, 4, 32 ~> 3, 2, 4, 32 ~> 5, 4, 32 ~> ... ~> 9, 32
^ ^ ^ ^
This has the advantage of not repacking the heavy-side of packs too
often while also only creating one new pack at a time. Another wrinkle
is that we assume that loose, indexed, and reflog'd objects are
insignificant, and lump them into any new pack that we create. This can
lead to non-idempotent results.
Suggested-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Specify the format of the on-disk reverse index 'pack-*.rev' file, as
well as prepare the code for the existence of such files.
The reverse index maps from pack relative positions (i.e., an index into
the array of object which is sorted by their offsets within the
packfile) to their position within the 'pack-*.idx' file. Today, this is
done by building up a list of (off_t, uint32_t) tuples for each object
(the off_t corresponding to that object's offset, and the uint32_t
corresponding to its position in the index). To convert between pack and
index position quickly, this array of tuples is radix sorted based on
its offset.
This has two major drawbacks:
First, the in-memory cost scales linearly with the number of objects in
a pack. Each 'struct revindex_entry' is sizeof(off_t) +
sizeof(uint32_t) + padding bytes for a total of 16.
To observe this, force Git to load the reverse index by, for e.g.,
running 'git cat-file --batch-check="%(objectsize:disk)"'. When asking
for a single object in a fresh clone of the kernel, Git needs to
allocate 120+ MB of memory in order to hold the reverse index in memory.
Second, the cost to sort also scales with the size of the pack.
Luckily, this is a linear function since 'load_pack_revindex()' uses a
radix sort, but this cost still must be paid once per pack per process.
As an example, it takes ~60x longer to print the _size_ of an object as
it does to print that entire object's _contents_:
Benchmark #1: git.compile cat-file --batch <obj
Time (mean ± σ): 3.4 ms ± 0.1 ms [User: 3.3 ms, System: 2.1 ms]
Range (min … max): 3.2 ms … 3.7 ms 726 runs
Benchmark #2: git.compile cat-file --batch-check="%(objectsize:disk)" <obj
Time (mean ± σ): 210.3 ms ± 8.9 ms [User: 188.2 ms, System: 23.2 ms]
Range (min … max): 193.7 ms … 224.4 ms 13 runs
Instead, avoid computing and sorting the revindex once per process by
writing it to a file when the pack itself is generated.
The format is relatively straightforward. It contains an array of
uint32_t's, the length of which is equal to the number of objects in the
pack. The ith entry in this table contains the index position of the
ith object in the pack, where "ith object in the pack" is determined by
pack offset.
One thing that the on-disk format does _not_ contain is the full (up to)
eight-byte offset corresponding to each object. This is something that
the in-memory revindex contains (it stores an off_t in 'struct
revindex_entry' along with the same uint32_t that the on-disk format
has). Omit it in the on-disk format, since knowing the index position
for some object is sufficient to get a constant-time lookup in the
pack-*.idx file to ask for an object's offset within the pack.
This trades off between the on-disk size of the 'pack-*.rev' file for
runtime to chase down the offset for some object. Even though the lookup
is constant time, the constant is heavier, since it can potentially
involve two pointer walks in v2 indexes (one to access the 4-byte offset
table, and potentially a second to access the double wide offset table).
Consider trying to map an object's pack offset to a relative position
within that pack. In a cold-cache scenario, more page faults occur while
switching between binary searching through the reverse index and
searching through the *.idx file for an object's offset. Sure enough,
with a cold cache (writing '3' into '/proc/sys/vm/drop_caches' after
'sync'ing), printing out the entire object's contents is still
marginally faster than printing its size:
Benchmark #1: git.compile cat-file --batch-check="%(objectsize:disk)" <obj >/dev/null
Time (mean ± σ): 22.6 ms ± 0.5 ms [User: 2.4 ms, System: 7.9 ms]
Range (min … max): 21.4 ms … 23.5 ms 41 runs
Benchmark #2: git.compile cat-file --batch <obj >/dev/null
Time (mean ± σ): 17.2 ms ± 0.7 ms [User: 2.8 ms, System: 5.5 ms]
Range (min … max): 15.6 ms … 18.2 ms 45 runs
(Numbers taken in the kernel after cheating and using the next patch to
generate a reverse index). There are a couple of approaches to improve
cold cache performance not pursued here:
- We could include the object offsets in the reverse index format.
Predictably, this does result in fewer page faults, but it triples
the size of the file, while simultaneously duplicating a ton of data
already available in the .idx file. (This was the original way I
implemented the format, and it did show
`--batch-check='%(objectsize:disk)'` winning out against `--batch`.)
On the other hand, this increase in size also results in a large
block-cache footprint, which could potentially hurt other workloads.
- We could store the mapping from pack to index position in more
cache-friendly way, like constructing a binary search tree from the
table and writing the values in breadth-first order. This would
result in much better locality, but the price you pay is trading
O(1) lookup in 'pack_pos_to_index()' for an O(log n) one (since you
can no longer directly index the table).
So, neither of these approaches are taken here. (Thankfully, the format
is versioned, so we are free to pursue these in the future.) But, cold
cache performance likely isn't interesting outside of one-off cases like
asking for the size of an object directly. In real-world usage, Git is
often performing many operations in the revindex (i.e., asking about
many objects rather than a single one).
The trade-off is worth it, since we will avoid the vast majority of the
cost of generating the revindex that the extra pointer chase will look
like noise in the following patch's benchmarks.
This patch describes the format and prepares callers (like in
pack-revindex.c) to be able to read *.rev files once they exist. An
implementation of the writer will appear in the next patch, and callers
will gradually begin to start using the writer in the patches that
follow after that.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Let's replace the 2 different pieces of code that write a
promisor file in 'builtin/repack.c' and 'fetch-pack.c'
with a new function called 'write_promisor_file()' in
'pack-write.c' and 'pack.h'.
This might also help us in the future, if we want to put
back the ref names and associated hashes that were in
the promisor files we are repacking in 'builtin/repack.c'
as suggested by a NEEDSWORK comment just above the code
we are refactoring.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When 'git repack' creates a pack with the same name as any existing
pack, it moves the existing one to 'old-pack-xxx.{pack,idx,...}' and
then renames the new one into place.
Eventually, it would be nice to have 'git repack' allow for writing a
multi-pack index at the critical time (after the new packs have been
written / moved into place, but before the old ones have been deleted).
Guessing that this option might be called '--write-midx', this makes the
following situation (where repacks are issued back-to-back without any
new objects) impossible:
$ git repack -adb
$ git repack -adb --write-midx
In the second repack, the existing packs are overwritten verbatim with
the same rename-to-old sequence. At that point, the current MIDX is
invalidated, since it refers to now-missing packs. So that code wants to
be run after the MIDX is re-written. But (prior to this patch) the new
MIDX can't be written until the new packs are moved into place. So, we
have a circular dependency.
This is all hypothetical, since no code currently exists to write a MIDX
safely during a 'git repack' (the 'GIT_TEST_MULTI_PACK_INDEX' does so
unsafely). Putting hypothetical aside, though: why do we need to rename
existing packs to be prefixed with 'old-' anyway?
This behavior dates all the way back to 2ad47d6 (git-repack: Be
careful when updating the same pack as an existing one., 2006-06-25).
2ad47d6 is mainly concerned about a case where a newly written pack
would have a different structure than its index. This used to be
possible when the pack name was a hash of the set of objects. Under this
naming scheme, two packs that store the same set of objects could differ
in delta selection, object positioning, or both. If this happened, then
any such packs would be unreadable in the instant between copying the
new pack and new index (i.e., either the index or pack will be stale
depending on the order that they were copied).
But since 1190a1a (pack-objects: name pack files after trailer hash,
2013-12-05), this is no longer possible, since pack files are named not
after their logical contents (i.e., the set of objects), but by the
actual checksum of their contents. So, this old- behavior can safely go,
which allows us to avoid our circular dependency above.
In addition to avoiding the circular dependency, this patch also makes
'git repack' a lot simpler, since we don't have to deal with failures
encountered when renaming existing packs to be prefixed with 'old-'.
This patch is mostly limited to removing code paths that deal with the
'old' prefixing, with the exception of files that include the pack's
name in their own filename, like .idx, .bitmap, and related files. The
exception is that we want to continue to trust what pack-objects wrote.
That is, it is not the case that we pretend as if pack-objects didn't
write files identical to ones that already exist, but rather that we
respect what pack-objects wrote as the source of truth. That cuts two
ways:
- If pack-objects produced an identical pack to one that already
exists with a bitmap, but did not produce a bitmap, we remove the
bitmap that already exists. (This behavior is codified in t7700.14).
- If pack-objects produced an identical pack to one that already
exists, we trust the just-written version of the coresponding .idx,
.promisor, and other files over the ones that already exist. This
ensures that we use the most up-to-date versions of this files,
which is safe even in the face of format changes in, say, the .idx
file (which would not be reflected in the .idx file's name).
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In the subsequent commit, it will become useful to keep track of which
metadata files were written by pack-objects. We already do this to an
extent with the 'exts' array, which only is used in the context of
existing packs.
Co-authored-by: Jeff King <peff@peff.net>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We'll use it in a helper function soon.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When a packfile is removed by "git repack", multi-pack-index gets
cleared; the code was taught to do so less aggressively by first
checking if the midx actually refers to a pack that no longer
exists.
* tb/repack-clearing-midx:
midx: traverse the local MIDX first
builtin/repack.c: invalidate MIDX only when necessary
When a repository has an alternate object directory configured, callers
can traverse through each alternate's MIDX by walking the '->next'
pointer.
But, when 'prepare_multi_pack_index_one()' loads multiple MIDXs, it
places the new ones at the front of this pointer chain, not at the end.
This can be confusing for callers such as 'git repack -ad', causing test
failures like in t7700.6 with 'GIT_TEST_MULTI_PACK_INDEX=1'.
The occurs when dropping a pack known to the local MIDX with alternates
configured that have their own MIDX. Since the alternate's MIDX is
returned via 'get_multi_pack_index()', 'midx_contains_pack()' returns
true (which is correct, since it traverses through the '->next' pointer
to find the MIDX in the chain that does contain the requested object).
But, we call 'clear_midx_file()' on 'the_repository', which drops the
MIDX at the path of the first MIDX in the chain, which (in the case of
t7700.6 is the one in the alternate).
This patch addresses that by:
- placing the local MIDX first in the chain when calling
'prepare_multi_pack_index_one()', and
- introducing a new 'get_local_multi_pack_index()', which explicitly
returns the repository-local MIDX, if any.
Don't impose an additional order on the MIDX's '->next' pointer beyond
that the first item in the chain must be local if one exists so that we
avoid a quadratic insertion.
Likewise, use 'get_local_multi_pack_index()' in
'remove_redundant_pack()' to fix the formerly broken t7700.6 when run
with 'GIT_TEST_MULTI_PACK_INDEX=1'.
Finally, note that the MIDX ordering invariant is only preserved by the
insertion order in 'prepare_packed_git()', which traverses through the
ODB's '->next' pointer, meaning we visit the local object store first.
This fragility makes this an undesirable long-term solution if more
callers are added, but it is acceptable for now since this is the only
caller.
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In 525e18c04b (midx: clear midx on repack, 2018-07-12), 'git repack'
learned to remove a multi-pack-index file if it added or removed a pack
from the object store.
This mechanism is a little over-eager, since it is only necessary to
drop a MIDX if 'git repack' removes a pack that the MIDX references.
Adding a pack outside of the MIDX does not require invalidating the
MIDX, and likewise for removing a pack the MIDX does not know about.
Teach 'git repack' to check for this by loading the MIDX, and checking
whether the to-be-removed pack is known to the MIDX. This requires a
slightly odd alternation to a test in t5319, which is explained with a
comment. A new test is added to show that the MIDX is left alone when
both packs known to it are marked as .keep, but two packs unknown to it
are removed and combined into one new pack.
Helped-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Code which split an argv_array call across multiple lines, like:
argv_array_pushl(&args, "one argument",
"another argument", "and more",
NULL);
was recently mechanically renamed to use strvec, which results in
mis-matched indentation like:
strvec_pushl(&args, "one argument",
"another argument", "and more",
NULL);
Let's fix these up to align the arguments with the opening paren. I did
this manually by sifting through the results of:
git jump grep 'strvec_.*,$'
and liberally applying my editor's auto-format. Most of the changes are
of the form shown above, though I also normalized a few that had
originally used a single-tab indentation (rather than our usual style of
aligning with the open paren). I also rewrapped a couple of obvious
cases (e.g., where previously too-long lines became short enough to fit
on one), but I wasn't aggressive about it. In cases broken to three or
more lines, the grouping of arguments is sometimes meaningful, and it
wasn't worth my time or reviewer time to ponder each case individually.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We eventually want to drop the argv_array name and just use strvec
consistently. There's no particular reason we have to do it all at once,
or care about interactions between converted and unconverted bits.
Because of our preprocessor compat layer, the names are interchangeable
to the compiler (so even a definition and declaration using different
names is OK).
This patch converts all of the files in builtin/ to keep the diff to a
manageable size.
The conversion was done purely mechanically with:
git ls-files '*.c' '*.h' |
xargs perl -i -pe '
s/ARGV_ARRAY/STRVEC/g;
s/argv_array/strvec/g;
'
and then selectively staging files with "git add builtin/". We'll deal
with any indentation/style fallouts separately.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This requires updating #include lines across the code-base, but that's
all fairly mechanical, and was done with:
git ls-files '*.c' '*.h' |
xargs perl -i -pe 's/argv-array.h/strvec.h/'
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are many functions in commit.h that are more related to shallow
repositories than they are to any sort of generic commit machinery.
Likely this began when there were only a few shallow-related functions,
and commit.h seemed a reasonable enough place to put them.
But, now there are a good number of shallow-related functions, and
placing them all in 'commit.h' doesn't make sense.
This patch extracts a 'shallow.h', which takes all of the declarations
from 'commit.h' for functions which already exist in 'shallow.c'. We
will bring the remaining shallow-related functions defined in 'commit.c'
in a subsequent patch.
For now, move only the ones that already are implemented in 'shallow.c',
and update the necessary includes.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In builtin.h, there exists the distinctly lib-ish function
prune_packed_objects(). This function can currently only be called by
built-in commands but, unlike all of the other functions in the header,
it does not make sense to impose this restriction as the functionality
can be logically reused in libgit.
Extract this function into prune-packed.c so that related definitions
can exist clearly in their own header file.
While we're at it, clean up #includes that are unused.
This patch is best viewed with --color-moved.
Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The code to generate multi-pack index learned to show (or not to
show) progress indicators.
* wb/midx-progress:
multi-pack-index: add [--[no-]progress] option.
midx: honor the MIDX_PROGRESS flag in midx_repack
midx: honor the MIDX_PROGRESS flag in verify_midx_file
midx: add progress to expire_midx_packs
midx: add progress to write_midx_file
midx: add MIDX_PROGRESS flag
Add the MIDX_PROGRESS flag and update the
write|verify|expire|repack functions in midx.h
to accept a flags parameter. The MIDX_PROGRESS
flag indicates whether the caller of the function
would like progress information to be displayed.
This patch only changes the method prototypes
and does not change the functionality. The
functionality change will be handled by a later patch.
Signed-off-by: William Baker <William.Baker@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The specification of promisor packfiles (in partial-clone.txt) states
that the .promisor files that accompany packfiles do not matter (just
like .keep files), so whenever a packfile is fetched from the promisor
remote, Git has been writing empty .promisor files. But these files
could contain more useful information.
So instead of writing empty files, write the refs fetched to these
files. This makes it easier to debug issues with partial clones, as we
can identify what refs (and their associated hashes) were fetched at the
time the packfile was downloaded, and if necessary, compare those hashes
against what the promisor remote reports now.
This is implemented by teaching fetch-pack to write its own non-empty
.promisor file whenever it knows the name of the pack's lockfile. This
covers the case wherein the user runs "git fetch" with an internal
protocol or HTTP protocol v2 (fetch_refs_via_pack() in transport.c sets
lock_pack) and with HTTP protocol v0/v1 (fetch_git() in remote-curl.c
passes "--lock-pack" to "fetch-pack").
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Acked-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Preparation for SHA-256 upgrade continues.
* bc/object-id-part17: (26 commits)
midx: switch to using the_hash_algo
builtin/show-index: replace sha1_to_hex
rerere: replace sha1_to_hex
builtin/receive-pack: replace sha1_to_hex
builtin/index-pack: replace sha1_to_hex
packfile: replace sha1_to_hex
wt-status: convert struct wt_status to object_id
cache: remove null_sha1
builtin/worktree: switch null_sha1 to null_oid
builtin/repack: write object IDs of the proper length
pack-write: use hash_to_hex when writing checksums
sequencer: convert to use the_hash_algo
bisect: switch to using the_hash_algo
sha1-lookup: switch hard-coded constants to the_hash_algo
config: use the_hash_algo in abbrev comparison
combine-diff: replace GIT_SHA1_HEXSZ with the_hash_algo
bundle: switch to use the_hash_algo
connected: switch GIT_SHA1_HEXSZ to the_hash_algo
show-index: switch hard-coded constants to the_hash_algo
blame: remove needless comparison with GIT_SHA1_HEXSZ
...
Teach the lazy clone machinery that there can be more than one
promisor remote and consult them in order when downloading missing
objects on demand.
* cc/multi-promisor:
Move core_partial_clone_filter_default to promisor-remote.c
Move repository_format_partial_clone to promisor-remote.c
Remove fetch-object.{c,h} in favor of promisor-remote.{c,h}
remote: add promisor and partial clone config to the doc
partial-clone: add multiple remotes in the doc
t0410: test fetching from many promisor remotes
builtin/fetch: remove unique promisor remote limitation
promisor-remote: parse remote.*.partialclonefilter
Use promisor_remote_get_direct() and has_promisor_remote()
promisor-remote: use repository_format_partial_clone
promisor-remote: add promisor_remote_reinit()
promisor-remote: implement promisor_remote_get_direct()
Add initial support for many promisor remotes
fetch-object: make functions return an error code
t0410: remove pipes after git commands
Use the_hash_algo when calling xwrite with a hex object ID so that the
proper amount of data is written.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commit 7328482253 (repack: disable bitmaps-by-default if .keep files
exist, 2019-06-29) taught repack to prefer disabling bitmaps to
duplicating objects (unless bitmaps were asked for explicitly).
But there's an easier way to do this: if we keep passing the
--honor-pack-keep flag to pack-objects when auto-enabling bitmaps, then
pack-objects already makes the same decision (it will disable bitmaps
rather than duplicate). Better still, pack-objects can actually decide
to do so based not just on the presence of a .keep file, but on whether
that .keep file actually impacts the new pack we're making (so if we're
racing with a push or fetch, for example, their temporary .keep file
will not block us from generating bitmaps if they haven't yet updated
their refs).
And because repack uses the --write-bitmap-index-quiet flag, we don't
have to worry about pack-objects generating confusing warnings when it
does see a .keep file. We can confirm this by tweaking the .keep test to
check repack's stderr.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Depending on various config options, a full repack may not be able to
build a reachability bitmap index (e.g., if pack.packSizeLimit forces us
to write multiple packs). In these cases pack-objects may write a
warning to stderr.
Since 36eba0323d (repack: enable bitmaps by default on bare repos,
2019-03-14), we may generate these warnings even when the user did not
explicitly ask for bitmaps. This has two downsides:
- it can be confusing, if they don't know what bitmaps are
- a daemonized auto-gc will write this to its log file, and the
presence of the warning may suppress further auto-gc (until
gc.logExpiry has elapsed)
Let's have repack communicate to pack-objects that the choice to turn on
bitmaps was not made explicitly by the user, which in turn allows
pack-objects to suppress these warnings.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Generation of pack bitmaps are now disabled when .keep files exist,
as these are mutually exclusive features.
* ew/repack-with-bitmaps-by-default:
repack: disable bitmaps-by-default if .keep files exist
"git multi-pack-index" learned expire and repack subcommands.
* ds/midx-expire-repack:
t5319: use 'test-tool path-utils' instead of 'ls -l'
t5319-multi-pack-index.sh: test batch size zero
midx: add test that 'expire' respects .keep files
multi-pack-index: test expire while adding packs
midx: implement midx_repack()
multi-pack-index: prepare 'repack' subcommand
multi-pack-index: implement 'expire' subcommand
midx: refactor permutation logic and pack sorting
midx: simplify computation of pack name lengths
multi-pack-index: prepare for 'expire' subcommand
Docs: rearrange subcommands for multi-pack-index
repack: refactor pack deletion for future use
The commit-graph file is now part of the "files that the runtime
may keep open file descriptors on, all of which would need to be
closed when done with the object store", and the file descriptor to
an existing commit-graph file now is closed before "gc" finalizes a
new instance to replace it.
* ds/close-object-store:
packfile: rename close_all_packs to close_object_store
packfile: close commit-graph in close_all_packs
commit-graph: use raw_object_store when closing
Bitmaps aren't useful with multiple packs, and users with
.keep files ended up with redundant packs when bitmaps
got enabled by default in bare repos.
So detect when .keep files exist and stop enabling bitmaps
by default in that case.
Wasteful (but otherwise harmless) race conditions with .keep files
documented by Jeff King still apply and there's a chance we'd
still end up with redundant data on the FS:
https://public-inbox.org/git/20190623224244.GB1100@sigill.intra.peff.net/
v2: avoid subshell in test case, be multi-index aware
Fixes: 36eba0323d ("repack: enable bitmaps by default on bare repos")
Signed-off-by: Eric Wong <e@80x24.org>
Helped-by: Jeff King <peff@peff.net>
Reported-by: Janos Farkas <chexum@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Instead of using the repository_format_partial_clone global
and fetch_objects() directly, let's use has_promisor_remote()
and promisor_remote_get_direct().
This way all the configured promisor remotes will be taken
into account, not only the one specified by
extensions.partialClone.
Also when cloning or fetching using a partial clone filter,
remote.origin.promisor will be set to "true" instead of
setting extensions.partialClone to "origin". This makes it
possible to use many promisor remote just by fetching from
them.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The close_all_packs() method is now responsible for more than just pack-files.
It also closes the commit-graph and the multi-pack-index. Rename the function
to be more descriptive of its larger role. The name also fits because the
input parameter is a raw_object_store.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The repack builtin deletes redundant pack-files and their
associated .idx, .promisor, .bitmap, and .keep files. We will want
to re-use this logic in the future for other types of repack, so
pull the logic into 'unlink_pack_path()' in packfile.c.
The 'ignore_keep' parameter is enabled for the use in repack, but
will be important for a future caller.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A typical use case for bare repos is for serving clones and
fetches to clients. Enable bitmaps by default on bare repos to
make it easier for admins to host git repos in a performant way.
Signed-off-by: Eric Wong <e@80x24.org>
Helped-by: Jeff King <peff@peff.net>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git gc" and "git repack" did not close the open packfiles that
they found unneeded before removing them, which didn't work on a
platform incapable of removing an open file. This has been
corrected.
* js/gc-repack-close-before-remove:
gc/repack: release packs when needed
On Windows, files cannot be removed nor renamed if there are still
handles held by a process. To remedy that, we introduced the
close_all_packs() function.
Earlier, we made sure that the packs are released just before `git gc`
is spawned, in case that gc wants to remove no-longer needed packs.
But this developer forgot that gc itself also needs to let go of packs,
e.g. when consolidating all packs via the --aggressive option.
Likewise, `git repack -d` wants to delete obsolete packs and therefore
needs to close all pack handles, too.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
More _("i18n") markings.
* nd/i18n:
fsck: mark strings for translation
fsck: reduce word legos to help i18n
parse-options.c: mark more strings for translation
parse-options.c: turn some die() to BUG()
parse-options: replace opterror() with optname()
repack: mark more strings for translation
remote.c: mark messages for translation
remote.c: turn some error() or die() to BUG()
reflog: mark strings for translation
read-cache.c: add missing colon separators
read-cache.c: mark more strings for translation
read-cache.c: turn die("internal error") to BUG()
attr.c: mark more string for translation
archive.c: mark more strings for translation
alias.c: mark split_cmdline_strerror() strings for translation
git.c: mark more strings for translation
Tests for the recently introduced multi-pack index machinery.
* ds/test-multi-pack-index:
packfile: close multi-pack-index in close_all_packs
multi-pack-index: define GIT_TEST_MULTI_PACK_INDEX
midx: close multi-pack-index on repack
midx: fix broken free() in close_midx()
Two strings are slightly updated to be consistent with the rest: die()
starts with lowercase.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git repack" in a shallow clone did not correctly update the
shallow points in the repository, leading to a repository that
does not pass fsck.
* js/shallow-and-fetch-prune:
repack -ad: prune the list of shallow commits
shallow: offer to prune only non-existing entries
repack: point out a bug handling stale shallow info
`git repack` can drop unreachable commits without further warning,
making the corresponding entries in `.git/shallow` invalid, which causes
serious problems when deepening the branches.
One scenario where unreachable commits are dropped by `git repack` is
when a `git fetch --prune` (or even a `git fetch` when a ref was
force-pushed in the meantime) can make a commit unreachable that was
reachable before.
Therefore it is not safe to assume that a `git repack -adlf` will keep
unreachable commits alone (under the assumption that they had not been
packed in the first place, which is an assumption at least some of Git's
code seems to make).
This is particularly important to keep in mind when looking at the
`.git/shallow` file: if any commits listed in that file become
unreachable, it is not a problem, but if they go missing, it *is* a
problem. One symptom of this problem is that a deepening fetch may now
fail with
fatal: error in object: unshallow <commit-hash>
To avoid this problem, let's prune the shallow list in `git repack` when
the `-d` option is passed, unless `-A` is passed, too (which would force
the now-unreachable objects to be turned into loose objects instead of
being deleted). Additionally, we also need to take `--keep-reachable`
and `--unpack-unreachable=<date>` into account.
Note: an alternative solution discussed during the review of this patch
was to teach `git fetch` to simply ignore entries in .git/shallow if the
corresponding commits do not exist locally. A quick test, however,
revealed that the .git/shallow file is written during a shallow *clone*,
in which case the commits do not exist, either, but the "shallow" line
*does* need to be sent. Therefore, this approach would be a lot more
finicky than the approach presented by the this patch.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The multi-pack-index feature is tested in isolation by
t5319-multi-pack-index.sh, but there are many more interesting
scenarios in the test suite surrounding pack-file data shapes
and interactions. Since the multi-pack-index is an optional
data structure, it does not make sense to include it by default
in those tests.
Instead, add a new GIT_TEST_MULTI_PACK_INDEX environment variable
that enables core.multiPackIndex and writes a multi-pack-index
after each 'git repack' command. This adds extra test coverage
when needed.
There are a few spots in the test suite that need to react to this
change:
* t5319-multi-pack-index.sh: there is a test that checks that
'git repack' deletes the multi-pack-index. Disable the environment
variable to ensure this still happens.
* t5310-pack-bitmaps.sh: One test moves a pack-file from the object
directory to an alternate. This breaks the multi-pack-index, so
delete the multi-pack-index at this point, if it exists.
* t9300-fast-import.sh: One test verifies the number of files in
the .git/objects/pack directory is exactly 8. Exclude the
multi-pack-index from this count so it is still 8 in all cases.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When repacking, we may remove pack-files. This invalidates the
multi-pack-index (if it exists). Previously, we removed the
multi-pack-index file before removing any pack-file. In some cases,
the repack command may load the multi-pack-index into memory. This
may lead to later in-memory references to the non-existent pack-
files.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Note that while the error messages here are not translated, the end user
should never see them. We invoke git pack-objects shortly before both
invocations, so we can be fairly certain that the data we're receiving
is in fact valid.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
