Commit Graph

420 Commits

Author SHA1 Message Date
Junio C Hamano
8585d6c04a Merge branch 'ps/rev-list-object-type-filter'
"git rev-list" learns the "--filter=object:type=<type>" option,
which can be used to exclude objects of the given kind from the
packfile generated by pack-objects.

* ps/rev-list-object-type-filter:
  rev-list: allow filtering of provided items
  pack-bitmap: implement combined filter
  pack-bitmap: implement object type filter
  list-objects: implement object type filter
  list-objects: support filtering by tag and commit
  list-objects: move tag processing into its own function
  revision: mark commit parents as NOT_USER_GIVEN
  uploadpack.txt: document implication of `uploadpackfilter.allow`
2021-05-07 12:47:41 +09:00
Junio C Hamano
13158b9910 Merge branch 'jk/promisor-optim'
Handling of "promisor packs" that allows certain objects to be
missing and lazily retrievable has been optimized (a bit).

* jk/promisor-optim:
  revision: avoid parsing with --exclude-promisor-objects
  lookup_unknown_object(): take a repository argument
  is_promisor_object(): free tree buffer after parsing
2021-04-30 13:50:24 +09:00
Junio C Hamano
2eebac2c49 Merge branch 'jk/pack-objects-bitmap-progress-fix'
When "git pack-objects" makes a literal copy of a part of existing
packfile using the reachability bitmaps, its update to the progress
meter was broken.

* jk/pack-objects-bitmap-progress-fix:
  pack-objects: update "nr_seen" progress based on pack-reused count
2021-04-20 17:23:35 -07:00
Patrick Steinhardt
9cf68b27d5 rev-list: allow filtering of provided items
When providing an object filter, it is currently impossible to also
filter provided items. E.g. when executing `git rev-list HEAD` , the
commit this reference points to will be treated as user-provided and is
thus excluded from the filtering mechanism. This makes it harder than
necessary to properly use the new `--filter=object:type` filter given
that even if the user wants to only see blobs, he'll still see commits
of provided references.

Improve this by introducing a new `--filter-provided-objects` option
to the git-rev-parse(1) command. If given, then all user-provided
references will be subject to filtering.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-19 14:09:11 -07:00
Jeff King
45a187cc34 lookup_unknown_object(): take a repository argument
All of the other lookup_foo() functions take a repository argument, but
lookup_unknown_object() was never converted, and it uses the_repository
internally. Let's fix that.

We could leave a wrapper that uses the_repository, but there aren't that
many calls, so we'll just convert them all. I looked briefly at each
site to see if we had a repository struct (besides the_repository) we
could pass, but none of them do (so this conversion to pass
the_repository is a pure noop in each case, though it does take us one
step closer to eventually getting rid of the_repository).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-13 13:18:46 -07:00
Jeff King
8e118e8490 pack-objects: update "nr_seen" progress based on pack-reused count
When serving a clone or fetch with bitmaps, after deciding which objects
need to be sent our "pack reuse" mechanism kicks in: we try to send
more-or-less verbatim a bunch of objects from the beginning of the
bitmapped packfile without even adding them to the to_pack.objects
array.

After deciding which objects will be in the "reused" portion, we update
nr_result to account for those, and then trigger display_progress() to
show the user (who is undoubtedly dazzled that we managed to enumerate
so many objects so quickly).

But then something confusing happens: the "Enumerating objects" progress
meter jumps _backwards_, counting up from zero the number of objects we
actually add into to_pack.objects.

This worked correctly once upon a time, but was broken in 5af050437a
(pack-objects: show some progress when counting kept objects,
2018-04-15), when the latter half of that progress meter switched to
using a separate nr_seen counter, rather than nr_result. Nobody noticed
for two reasons:

  - prior to the pack-reuse fixes from a14aebeac3 (Merge branch
    'jk/packfile-reuse-cleanup', 2020-02-14), the reuse code almost
    never kicked in anyway

  - the output looks _kind of_ correct. The "backwards" moment is hard
    to catch, because we overwrite the old progress number with the new
    one, and the larger number is displayed only for a second. So unless
    you look at that exact second, you just see the much smaller value,
    counting up to the number of non-reused objects (though of course if
    you catch it in stderr, or look at GIT_TRACE_PACKET from a server
    with bitmaps, you can see both values).

This smaller output isn't wrong per se, but isn't counting what we ever
intended to. We should give the user the whole number of objects we
considered (which, as per 5af050437a's original purpose, is already
_not_ a count of what goes into to_pack.objects). The follow-on
"Counting objects" meter shows the actual number of objects we feed into
that array.

We can easily fix this by bumping (and showing) nr_seen for the
pack-reused objects. When the included test is run without this patch,
the second pack-objects invocation produces "Enumerating objects: 1" to
show the one loose object, even though the resulting pack has hundreds
of objects in it. With it, we jump to "Enumerating objects: 674" after
deciding on reuse, and then "675" when we add in the loose object.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-12 11:31:30 -07:00
Taylor Blau
3f267a1128 builtin/pack-objects.c: respect 'pack.preferBitmapTips'
When writing a new pack with a bitmap, it is sometimes convenient to
indicate some reference prefixes which should receive priority when
selecting which commits to receive bitmaps.

A truly motivated caller could accomplish this by setting
'pack.islandCore', (since all commits in the core island are similarly
marked as preferred) but this requires callers to opt into using delta
islands, which they may or may not want to do.

Introduce a new multi-valued configuration, 'pack.preferBitmapTips' to
allow callers to specify a list of reference prefixes. All references
which have a prefix contained in 'pack.preferBitmapTips' will mark their
tips as "preferred" in the same way as commits are marked as preferred
for selection by 'pack.islandCore'.

The choice of the verb "prefer" is intentional: marking the NEEDS_BITMAP
flag on an object does *not* guarantee that that object will receive a
bitmap. It merely guarantees that that commit will receive a bitmap over
any *other* commit in the same window by bitmap_writer_select_commits().

The test this patch adds reflects this quirk, too. It only tests that
a commit (which didn't receive bitmaps by default) is selected for
bitmaps after changing the value of 'pack.preferBitmapTips' to include
it. Other commits may lose their bitmaps as a byproduct of how the
selection process works (bitmap_writer_select_commits() ignores the
remainder of a window after seeing a commit with the NEEDS_BITMAP flag).

This configuration will aide in selecting important references for
multi-pack bitmaps, since they do not respect the same pack.islandCore
configuration. (They could, but doing so may be confusing, since it is
packs--not bitmaps--which are influenced by the delta-islands
configuration).

In a fork network repository (one which lists all forks of a given
repository as remotes), for example, it is useful to set
pack.preferBitmapTips to 'refs/remotes/<root>/heads' and
'refs/remotes/<root>/tags', where '<root>' is an opaque identifier
referring to the repository which is at the base of the fork chain.

Suggested-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-31 23:14:03 -07:00
Junio C Hamano
4730c5e273 Merge branch 'hx/pack-objects-chunk-comment'
Comment update.

* hx/pack-objects-chunk-comment:
  pack-objects: fix comment of reused_chunk.difference
2021-03-30 14:35:37 -07:00
Junio C Hamano
2744383cbd Merge branch 'tb/geometric-repack'
"git repack" so far has been only capable of repacking everything
under the sun into a single pack (or split by size).  A cleverer
strategy to reduce the cost of repacking a repository has been
introduced.

* tb/geometric-repack:
  builtin/pack-objects.c: ignore missing links with --stdin-packs
  builtin/repack.c: reword comment around pack-objects flags
  builtin/repack.c: be more conservative with unsigned overflows
  builtin/repack.c: assign pack split later
  t7703: test --geometric repack with loose objects
  builtin/repack.c: do not repack single packs with --geometric
  builtin/repack.c: add '--geometric' option
  packfile: add kept-pack cache for find_kept_pack_entry()
  builtin/pack-objects.c: rewrite honor-pack-keep logic
  p5303: measure time to repack with keep
  p5303: add missing &&-chains
  builtin/pack-objects.c: add '--stdin-packs' option
  revision: learn '--no-kept-objects'
  packfile: introduce 'find_kept_pack_entry()'
2021-03-24 14:36:27 -07:00
Han Xin
bf12013f1a pack-objects: fix comment of reused_chunk.difference
As record_reused_object(offset, offset - hashfile_total(out)) said,
reused_chunk.difference should be the offset of original packfile minus
the offset of the generated packfile. But the comment presented an opposite way.

Signed-off-by: Han Xin <hanxin.hx@alibaba-inc.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-24 13:03:22 -07:00
Taylor Blau
14e7b8344f builtin/pack-objects.c: ignore missing links with --stdin-packs
When 'git pack-objects --stdin-packs' encounters a commit in a pack, it
marks it as a starting point of a best-effort reachability traversal
that is used to populate the name-hash of the objects listed in the
given packs.

The traversal expects that it should be able to walk the ancestors of
all commits in a pack without issue. Ordinarily this is the case, but it
is possible to having missing parents from an unreachable part of the
repository. In that case, we'd consider any missing objects in the
unreachable portion of the graph to be junk.

This should be handled gracefully: since the traversal is best-effort
(i.e., we don't strictly need to fill in all of the name-hash fields),
we should simply ignore any missing links.

This patch does that (by setting the 'ignore_missing_links' bit on the
rev_info struct), and ensures we don't regress in the future by adding a
test which demonstrates this case.

It is a little over-eager, since it will also ignore missing links in
reachable parts of the packs (which would indicate a corrupted
repository), but '--stdin-packs' is explicitly *not* about reachability.
So this step isn't making anything worse for a repository which contains
packs missing reachable objects (since we never drop objects with
'--stdin-packs').

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-19 11:19:29 -07:00
René Scharfe
ca56dadb4b use CALLOC_ARRAY
Add and apply a semantic patch for converting code that open-codes
CALLOC_ARRAY to use it instead.  It shortens the code and infers the
element size automatically.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-13 16:00:09 -08:00
Jeff King
6325da14af builtin/pack-objects.c: rewrite honor-pack-keep logic
Now that we have find_kept_pack_entry(), we don't have to manually keep
hunting through every pack to find a possible "kept" duplicate of the
object. This should be faster, assuming only a portion of your total
packs are actually kept.

Note that we have to re-order the logic a bit here; we can deal with the
disqualifying situations first (e.g., finding the object in a non-local
pack with --local), then "kept" situation(s), and then just fall back to
other "--local" conditions.

Here are the results from p5303 (measurements again taken on the
kernel):

  Test                                        HEAD^                   HEAD
  -----------------------------------------------------------------------------------------------
  5303.5: repack (1)                          57.26(54.59+10.84)      57.34(54.66+10.88) +0.1%
  5303.6: repack with kept (1)                57.33(54.80+10.51)      57.38(54.83+10.49) +0.1%
  5303.11: repack (50)                        71.54(88.57+4.84)       71.70(88.99+4.74) +0.2%
  5303.12: repack with kept (50)              85.12(102.05+4.94)      72.58(89.61+4.78) -14.7%
  5303.17: repack (1000)                      216.87(490.79+14.57)    217.19(491.72+14.25) +0.1%
  5303.18: repack with kept (1000)            665.63(938.87+15.76)    246.12(520.07+14.93) -63.0%

and the --stdin-packs timings:

  5303.7: repack with --stdin-packs (1)       0.01(0.01+0.00)         0.00(0.00+0.00) -100.0%
  5303.13: repack with --stdin-packs (50)     3.53(12.07+0.24)        3.43(11.75+0.24) -2.8%
  5303.19: repack with --stdin-packs (1000)   195.83(371.82+8.10)     130.50(307.15+7.66) -33.4%

So our repack with an empty .keep pack is roughly as fast as one without
a .keep pack up to 50 packs. But the --stdin-packs case scales a little
better, too.

Notably, it is faster than a repack of the same size and a kept pack. It
looks at fewer objects, of course, but the penalty for looking at many
packs isn't as costly.

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>
2021-02-22 23:30:52 -08:00
Taylor Blau
339bce27f4 builtin/pack-objects.c: add '--stdin-packs' option
In an upcoming commit, 'git repack' will want to create a pack comprised
of all of the objects in some packs (the included packs) excluding any
objects in some other packs (the excluded packs).

This caller could iterate those packs themselves and feed the objects it
finds to 'git pack-objects' directly over stdin, but this approach has a
few downsides:

  - It requires every caller that wants to drive 'git pack-objects' in
    this way to implement pack iteration themselves. This forces the
    caller to think about details like what order objects are fed to
    pack-objects, which callers would likely rather not do.

  - If the set of objects in included packs is large, it requires
    sending a lot of data over a pipe, which is inefficient.

  - The caller is forced to keep track of the excluded objects, too, and
    make sure that it doesn't send any objects that appear in both
    included and excluded packs.

But the biggest downside is the lack of a reachability traversal.
Because the caller passes in a list of objects directly, those objects
don't get a namehash assigned to them, which can have a negative impact
on the delta selection process, causing 'git pack-objects' to fail to
find good deltas even when they exist.

The caller could formulate a reachability traversal themselves, but the
only way to drive 'git pack-objects' in this way is to do a full
traversal, and then remove objects in the excluded packs after the
traversal is complete. This can be detrimental to callers who care
about performance, especially in repositories with many objects.

Introduce 'git pack-objects --stdin-packs' which remedies these four
concerns.

'git pack-objects --stdin-packs' expects a list of pack names on stdin,
where 'pack-xyz.pack' denotes that pack as included, and
'^pack-xyz.pack' denotes it as excluded. The resulting pack includes all
objects that are present in at least one included pack, and aren't
present in any excluded pack.

To address the delta selection problem, 'git pack-objects --stdin-packs'
works as follows. First, it assembles a list of objects that it is going
to pack, as above. Then, a reachability traversal is started, whose tips
are any commits mentioned in included packs. Upon visiting an object, we
find its corresponding object_entry in the to_pack list, and set its
namehash parameter appropriately.

To avoid the traversal visiting more objects than it needs to, the
traversal is halted upon encountering an object which can be found in an
excluded pack (by marking the excluded packs as kept in-core, and
passing --no-kept-objects=in-core to the revision machinery).

This can cause the traversal to halt early, for example if an object in
an included pack is an ancestor of ones in excluded packs. But stopping
early is OK, since filling in the namehash fields of objects in the
to_pack list is only additive (i.e., having it helps the delta selection
process, but leaving it blank doesn't impact the correctness of the
resulting pack).

Even still, it is unlikely that this hurts us much in practice, since
the 'git repack --geometric' caller (which is introduced in a later
commit) marks small packs as included, and large ones as excluded.
During ordinary use, the small packs usually represent pushes after a
large repack, and so are unlikely to be ancestors of objects that
already exist in the repository.

(I found it convenient while developing this patch to have 'git
pack-objects' report the number of objects which were visited and got
their namehash fields filled in during traversal. This is also included
in the below patch via trace2 data lines).

Suggested-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-22 23:30:52 -08:00
Junio C Hamano
3c12d0b885 Merge branch 'tb/pack-revindex-on-disk'
Introduce an on-disk file to record revindex for packdata, which
traditionally was always created on the fly and only in-core.

* tb/pack-revindex-on-disk:
  t5325: check both on-disk and in-memory reverse index
  pack-revindex: ensure that on-disk reverse indexes are given precedence
  t: support GIT_TEST_WRITE_REV_INDEX
  t: prepare for GIT_TEST_WRITE_REV_INDEX
  Documentation/config/pack.txt: advertise 'pack.writeReverseIndex'
  builtin/pack-objects.c: respect 'pack.writeReverseIndex'
  builtin/index-pack.c: write reverse indexes
  builtin/index-pack.c: allow stripping arbitrary extensions
  pack-write.c: prepare to write 'pack-*.rev' files
  packfile: prepare for the existence of '*.rev' files
2021-02-12 14:21:04 -08:00
Junio C Hamano
77db59c2f9 Merge branch 'jv/pack-objects-narrower-ref-iteration'
The "pack-objects" command needs to iterate over all the tags when
automatic tag following is enabled, but it actually iterated over
all refs and then discarded everything outside "refs/tags/"
hierarchy, which was quite wasteful.

* jv/pack-objects-narrower-ref-iteration:
  builtin/pack-objects.c: avoid iterating all refs
2021-02-05 16:40:45 -08:00
Junio C Hamano
973e20b83f Merge branch 'jk/peel-iterated-oid'
The peel_ref() API has been replaced with peel_iterated_oid().

* jk/peel-iterated-oid:
  refs: switch peel_ref() to peel_iterated_oid()
2021-02-03 15:04:49 -08:00
Taylor Blau
e8c58f894b t: support GIT_TEST_WRITE_REV_INDEX
Add a new option that unconditionally enables the pack.writeReverseIndex
setting in order to run the whole test suite in a mode that generates
on-disk reverse indexes. Additionally, enable this mode in the second
run of tests under linux-gcc in 'ci/run-build-and-tests.sh'.

Once on-disk reverse indexes are proven out over several releases, we
can change the default value of that configuration to 'true', and drop
this patch.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-25 18:32:44 -08:00
Taylor Blau
c97733435a builtin/pack-objects.c: respect 'pack.writeReverseIndex'
Now that we have an implementation that can write the new reverse index
format, enable writing a .rev file in 'git pack-objects' by consulting
the pack.writeReverseIndex configuration variable.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-25 18:32:43 -08:00
Jacob Vosmaer
be18153b97 builtin/pack-objects.c: avoid iterating all refs
In git-pack-objects, we iterate over all the tags if the --include-tag
option is passed on the command line. For some reason this uses
for_each_ref which is expensive if the repo has many refs. We should
use for_each_tag_ref instead.

Because the add_ref_tag callback will now only visit tags we
simplified it a bit.

The motivation for this change is that we observed performance issues
with a repository on gitlab.com that has 500,000 refs but only 2,000
tags. The fetch traffic on that repo is dominated by CI, and when we
changed CI to fetch with 'git fetch --no-tags' we saw a dramatic
change in the CPU profile of git-pack-objects. This lead us to this
particular ref walk. More details in:
https://gitlab.com/gitlab-com/gl-infra/scalability/-/issues/746#note_483546598

Signed-off-by: Jacob Vosmaer <jacob@gitlab.com>
Reviewed-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-22 17:27:42 -08:00
Jeff King
36a317929b refs: switch peel_ref() to peel_iterated_oid()
The peel_ref() interface is confusing and error-prone:

  - it's typically used by ref iteration callbacks that have both a
    refname and oid. But since they pass only the refname, we may load
    the ref value from the filesystem again. This is inefficient, but
    also means we are open to a race if somebody simultaneously updates
    the ref. E.g., this:

      int some_ref_cb(const char *refname, const struct object_id *oid, ...)
      {
              if (!peel_ref(refname, &peeled))
                      printf("%s peels to %s",
                             oid_to_hex(oid), oid_to_hex(&peeled);
      }

    could print nonsense. It is correct to say "refname peels to..."
    (you may see the "before" value or the "after" value, either of
    which is consistent), but mentioning both oids may be mixing
    before/after values.

    Worse, whether this is possible depends on whether the optimization
    to read from the current iterator value kicks in. So it is actually
    not possible with:

      for_each_ref(some_ref_cb);

    but it _is_ possible with:

      head_ref(some_ref_cb);

    which does not use the iterator mechanism (though in practice, HEAD
    should never peel to anything, so this may not be triggerable).

  - it must take a fully-qualified refname for the read_ref_full() code
    path to work. Yet we routinely pass it partial refnames from
    callbacks to for_each_tag_ref(), etc. This happens to work when
    iterating because there we do not call read_ref_full() at all, and
    only use the passed refname to check if it is the same as the
    iterator. But the requirements for the function parameters are quite
    unclear.

Instead of taking a refname, let's instead take an oid. That fixes both
problems. It's a little funny for a "ref" function not to involve refs
at all. The key thing is that it's optimizing under the hood based on
having access to the ref iterator. So let's change the name to make it
clear why you'd want this function versus just peel_object().

There are two other directions I considered but rejected:

  - we could pass the peel information into the each_ref_fn callback.
    However, we don't know if the caller actually wants it or not. For
    packed-refs, providing it is essentially free. But for loose refs,
    we actually have to peel the object, which would be wasteful in most
    cases. We could likewise pass in a flag to the callback indicating
    whether the peeled information is known, but that complicates those
    callbacks, as they then have to decide whether to manually peel
    themselves. Plus it requires changing the interface of every
    callback, whether they care about peeling or not, and there are many
    of them.

  - we could make a function to return the peeled value of the current
    iterated ref (computing it if necessary), and BUG() otherwise. I.e.:

      int peel_current_iterated_ref(struct object_id *out);

    Each of the current callers is an each_ref_fn callback, so they'd
    mostly be happy. But:

      - we use those callbacks with functions like head_ref(), which do
        not use the iteration code. So we'd need to handle the fallback
        case there, anyway.

      - it's possible that a caller would want to call into generic code
        that sometimes is used during iteration and sometimes not. This
        encapsulates the logic to do the fast thing when possible, and
        fallback when necessary.

The implementation is mostly obvious, but I want to call out a few
things in the patch:

  - the test-tool coverage for peel_ref() is now meaningless, as it all
    collapses to a single peel_object() call (arguably they were pretty
    uninteresting before; the tricky part of that function is the
    fast-path we see during iteration, but these calls didn't trigger
    that). I've just dropped it entirely, though note that some other
    tests relied on the tags we created; I've moved that creation to the
    tests where it matters.

  - we no longer need to take a ref_store parameter, since we'd never
    look up a ref now. We do still rely on a global "current iterator"
    variable which _could_ be kept per-ref-store. But in practice this
    is only useful if there are multiple recursive iterations, at which
    point the more appropriate solution is probably a stack of
    iterators. No caller used the actual ref-store parameter anyway
    (they all call the wrapper that passes the_repository).

  - the original only kicked in the optimization when the "refname"
    pointer matched (i.e., not string comparison). We do likewise with
    the "oid" parameter here, but fall back to doing an actual oideq()
    call. This in theory lets us kick in the optimization more often,
    though in practice no current caller cares. It should never be
    wrong, though (peeling is a property of an object, so two refs
    pointing to the same object would peel identically).

  - the original took care not to touch the peeled out-parameter unless
    we found something to put in it. But no caller cares about this, and
    anyway, it is enforced by peel_object() itself (and even in the
    optimized iterator case, that's where we eventually end up). We can
    shorten the code and avoid an extra copy by just passing the
    out-parameter through the stack.

Signed-off-by: Jeff King <peff@peff.net>
Reviewed-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-21 15:51:31 -08:00
Taylor Blau
eb3fd99efd check_object(): convert to new revindex API
Replace direct accesses to the revindex with calls to
'offset_to_pack_pos()' and 'pack_pos_to_index()'.

Since this caller already had some error checking (it can jump to the
'give_up' label if it encounters an error), we can easily check whether
or not the provided offset points to an object in the given pack. This
error checking existed prior to this patch, too, since the caller checks
whether the return value from 'find_pack_revindex()' was NULL or not.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-13 21:53:45 -08:00
Taylor Blau
6a5c10c45f write_reused_pack_verbatim(): convert to new revindex API
Replace a direct access to the revindex array with
'pack_pos_to_offset()'.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-13 21:53:45 -08:00
Taylor Blau
66cbd3e2fb write_reused_pack_one(): convert to new revindex API
Replace direct revindex accesses with calls to 'pack_pos_to_offset()'
and 'pack_pos_to_index()'.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-13 21:53:45 -08:00
Taylor Blau
952fc6870d write_reuse_object(): convert to new revindex API
First replace 'find_pack_revindex()' with its replacement
'offset_to_pack_pos()'. This prevents any bogus OFS_DELTA that may make
its way through until 'write_reuse_object()' from causing a bad memory
read (if 'revidx' is 'NULL')

Next, replace a direct access of '->nr' with the wrapper function
'pack_pos_to_index()'.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-13 21:53:45 -08:00
Jeff King
449fa5ee06 pack-bitmap-write: ignore BITMAP_FLAG_REUSE
The on-disk bitmap format has a flag to mark a bitmap to be "reused".
This is a rather curious feature, and works like this:

  - a run of pack-objects would decide to mark the last 80% of the
    bitmaps it generates with the reuse flag

  - the next time we generate bitmaps, we'd see those reuse flags from
    the last run, and mark those commits as special:

      - we'd be more likely to select those commits to get bitmaps in
        the new output

      - when generating the bitmap for a selected commit, we'd reuse the
        old bitmap as-is (rearranging the bits to match the new pack, of
        course)

However, neither of these behaviors particularly makes sense.

Just because a commit happened to be bitmapped last time does not make
it a good candidate for having a bitmap this time. In particular, we may
choose bitmaps based on how recent they are in history, or whether a ref
tip points to them, and those things will change. We're better off
re-considering fresh which commits are good candidates.

Reusing the existing bitmap _is_ a reasonable thing to do to save
computation. But only reusing exact bitmaps is a weak form of this. If
we have an old bitmap for A and now want a new bitmap for its child, we
should be able to compute that only by looking at trees and that are new
to the child. But this code would consider only exact reuse (which is
perhaps why it was eager to select those commits in the first place).

Furthermore, the recent switch to the reverse-edge algorithm for
generating bitmaps dropped this optimization entirely (and yet still
performs better).

So let's do a few cleanups:

 - drop the whole "reusing bitmaps" phase of generating bitmaps. It's
   not helping anything, and is mostly unused code (or worse, code that
   is using CPU but not doing anything useful)

 - drop the use of the on-disk reuse flag to select commits to bitmap

 - stop setting the on-disk reuse flag in bitmaps we generate (since
   nothing respects it anymore)

We will keep a few innards of the reuse code, which will help us
implement a more capable version of the "reuse" optimization:

 - simplify rebuild_existing_bitmaps() into a function that only builds
   the mapping of bits between the old and new orders, but doesn't
   actually convert any bitmaps

 - make rebuild_bitmap() public; we'll call it lazily to convert bitmaps
   as we traverse (using the mapping created above)

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>
2020-12-08 14:48:17 -08:00
Junio C Hamano
2a978f8273 Merge branch 'jc/object-names-are-not-sha-1'
A few end-user facing messages have been updated to be
hash-algorithm agnostic.

* jc/object-names-are-not-sha-1:
  messages: avoid SHA-1 in end-user facing messages
2020-08-19 16:14:52 -07:00
Junio C Hamano
4279000d3e messages: avoid SHA-1 in end-user facing messages
There are still a handful mentions of SHA-1 when we meant the
(hexadecimal) object names in end-user facing messages.  Rewrite
them.

I was hoping that this can mostly be s/SHA-1/object name/, but
a few messages needed rephrasing to keep the result readable.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-14 09:33:37 -07:00
Junio C Hamano
d1a8a8979d Merge branch 'jt/has_object'
A new helper function has_object() has been introduced to make it
easier to mark object existence checks that do and don't want to
trigger lazy fetches, and a few such checks are converted using it.

* jt/has_object:
  fsck: do not lazy fetch known non-promisor object
  pack-objects: no fetch when allow-{any,promisor}
  apply: do not lazy fetch when applying binary
  sha1-file: introduce no-lazy-fetch has_object()
2020-08-13 14:13:39 -07:00
Junio C Hamano
46b225f153 Merge branch 'jk/strvec'
The argv_array API is useful for not just managing argv but any
"vector" (NULL-terminated array) of strings, and has seen adoption
to a certain degree.  It has been renamed to "strvec" to reduce the
barrier to adoption.

* jk/strvec:
  strvec: rename struct fields
  strvec: drop argv_array compatibility layer
  strvec: update documention to avoid argv_array
  strvec: fix indentation in renamed calls
  strvec: convert remaining callers away from argv_array name
  strvec: convert more callers away from argv_array name
  strvec: convert builtin/ callers away from argv_array name
  quote: rename sq_dequote_to_argv_array to mention strvec
  strvec: rename files from argv-array to strvec
  argv-array: rename to strvec
  argv-array: use size_t for count and alloc
2020-08-10 10:23:57 -07:00
Jonathan Tan
ee47243d76 pack-objects: no fetch when allow-{any,promisor}
The options --missing=allow-{any,promisor} were introduced in caf3827e2f
("rev-list: add list-objects filtering support", 2017-11-22) with the
following note in the commit message:

    This patch introduces handling of missing objects to help
    debugging and development of the "partial clone" mechanism,
    and once the mechanism is implemented, for a power user to
    perform operations that are missing-object aware without
    incurring the cost of checking if a missing link is expected.

The idea that these options are missing-object aware (and thus do not
need to lazily fetch objects, unlike unaware commands that assume that
all objects are present) are assumed in later commits such as 07ef3c6604
("fetch test: use more robust test for filtered objects", 2020-01-15).

However, the current implementations of these options use
has_object_file(), which indeed lazily fetches missing objects. Teach
these implementations not to do so. Also, update the documentation of
these options to be clearer.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-06 13:01:03 -07:00
Jeff King
d70a9eb611 strvec: rename struct fields
The "argc" and "argv" names made sense when the struct was argv_array,
but now they're just confusing. Let's rename them to "nr" (which we use
for counts elsewhere) and "v" (which is rather terse, but reads well
when combined with typical variable names like "args.v").

Note that we have to update all of the callers immediately. Playing
tricks with the preprocessor is hard here, because we wouldn't want to
rewrite unrelated tokens.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-30 19:18:06 -07:00
Jeff King
22f9b7f3f5 strvec: convert builtin/ callers away from argv_array name
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>
2020-07-28 15:02:18 -07:00
Jeff King
dbbcd44fb4 strvec: rename files from argv-array to strvec
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>
2020-07-28 15:02:17 -07:00
Jonathan Tan
e00549aa9b pack-objects: prefetch objects to be packed
When an object to be packed is noticed to be missing, prefetch all
to-be-packed objects in one batch.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-21 14:29:42 -07:00
Jonathan Tan
8d5cf95735 pack-objects: refactor to oid_object_info_extended
Use oid_object_info_extended() instead of oid_object_info() because a
subsequent commit needs to specify an additional flag here.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-21 14:29:42 -07:00
Jonathan Tan
dd4b732df7 upload-pack: send part of packfile response as uri
Teach upload-pack to send part of its packfile response as URIs.

An administrator may configure a repository with one or more
"uploadpack.blobpackfileuri" lines, each line containing an OID, a pack
hash, and a URI. A client may configure fetch.uriprotocols to be a
comma-separated list of protocols that it is willing to use to fetch
additional packfiles - this list will be sent to the server. Whenever an
object with one of those OIDs would appear in the packfile transmitted
by upload-pack, the server may exclude that object, and instead send the
URI. The client will then download the packs referred to by those URIs
before performing the connectivity check.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-06-10 18:06:34 -07:00
Junio C Hamano
896833b268 Merge branch 'tb/shallow-cleanup'
Code cleanup.

* tb/shallow-cleanup:
  shallow: use struct 'shallow_lock' for additional safety
  shallow.h: document '{commit,rollback}_shallow_file'
  shallow: extract a header file for shallow-related functions
  commit: make 'commit_graft_pos' non-static
2020-05-13 12:19:18 -07:00
Taylor Blau
120ad2b0f1 shallow: extract a header file for shallow-related functions
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>
2020-04-30 14:19:13 -07:00
Denton Liu
203c85339f Use OPT_CALLBACK and OPT_CALLBACK_F
In the codebase, there are many options which use OPTION_CALLBACK in a
plain ol' struct definition. However, we have the OPT_CALLBACK and
OPT_CALLBACK_F macros which are meant to abstract these plain struct
definitions away. These macros are useful as they semantically signal to
developers that these are just normal callback option with nothing fancy
happening.

Replace plain struct definitions of OPTION_CALLBACK with OPT_CALLBACK or
OPT_CALLBACK_F where applicable. The heavy lifting was done using the
following (disgusting) shell script:

	#!/bin/sh

	do_replacement () {
		tr '\n' '\r' |
			sed -e 's/{\s*OPTION_CALLBACK,\s*\([^,]*\),\([^,]*\),\([^,]*\),\([^,]*\),\([^,]*\),\s*0,\(\s*[^[:space:]}]*\)\s*}/OPT_CALLBACK(\1,\2,\3,\4,\5,\6)/g' |
			sed -e 's/{\s*OPTION_CALLBACK,\s*\([^,]*\),\([^,]*\),\([^,]*\),\([^,]*\),\([^,]*\),\([^,]*\),\(\s*[^[:space:]}]*\)\s*}/OPT_CALLBACK_F(\1,\2,\3,\4,\5,\6,\7)/g' |
			tr '\r' '\n'
	}

	for f in $(git ls-files \*.c)
	do
		do_replacement <"$f" >"$f.tmp"
		mv "$f.tmp" "$f"
	done

The result was manually inspected and then reformatted to match the
style of the surrounding code. Finally, using
`git grep OPTION_CALLBACK \*.c`, leftover results which were not handled
by the script were manually transformed.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-28 10:47:10 -07:00
Junio C Hamano
a768f866e9 Merge branch 'jk/oid-array-cleanups'
Code cleanup.

* jk/oid-array-cleanups:
  oidset: stop referring to sha1-array
  ref-filter: stop referring to "sha1 array"
  bisect: stop referring to sha1_array
  test-tool: rename sha1-array to oid-array
  oid_array: rename source file from sha1-array
  oid_array: use size_t for iteration
  oid_array: use size_t for count and allocation
2020-04-22 13:42:49 -07:00
Jeff King
fe299ec5ae oid_array: rename source file from sha1-array
We renamed the actual data structure in 910650d2f8 (Rename sha1_array to
oid_array, 2017-03-31), but the file is still called sha1-array. Besides
being slightly confusing, it makes it more annoying to grep for leftover
occurrences of "sha1" in various files, because the header is included
in so many places.

Let's complete the transition by renaming the source and header files
(and fixing up a few comment references).

I kept the "-" in the name, as that seems to be our style; cf.
fc1395f4a4 (sha1_file.c: rename to use dash in file name, 2018-04-10).
We also have oidmap.h and oidset.h without any punctuation, but those
are "struct oidmap" and "struct oidset" in the code. We _could_ make
this "oidarray" to match, but somehow it looks uglier to me because of
the length of "array" (plus it would be a very invasive patch for little
gain).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-03-30 10:59:08 -07:00
Junio C Hamano
9fadedd637 Merge branch 'ds/default-pack-use-sparse-to-true'
The 'pack.useSparse' configuration variable now defaults to 'true',
enabling an optimization that has been experimental since Git 2.21.

* ds/default-pack-use-sparse-to-true:
  pack-objects: flip the use of GIT_TEST_PACK_SPARSE
  config: set pack.useSparse=true by default
2020-03-29 09:32:51 -07:00
Junio C Hamano
f8cb64e3d4 Merge branch 'bc/sha-256-part-1-of-4'
SHA-256 transition continues.

* bc/sha-256-part-1-of-4: (22 commits)
  fast-import: add options for rewriting submodules
  fast-import: add a generic function to iterate over marks
  fast-import: make find_marks work on any mark set
  fast-import: add helper function for inserting mark object entries
  fast-import: permit reading multiple marks files
  commit: use expected signature header for SHA-256
  worktree: allow repository version 1
  init-db: move writing repo version into a function
  builtin/init-db: add environment variable for new repo hash
  builtin/init-db: allow specifying hash algorithm on command line
  setup: allow check_repository_format to read repository format
  t/helper: make repository tests hash independent
  t/helper: initialize repository if necessary
  t/helper/test-dump-split-index: initialize git repository
  t6300: make hash algorithm independent
  t6300: abstract away SHA-1-specific constants
  t: use hash-specific lookup tables to define test constants
  repository: require a build flag to use SHA-256
  hex: add functions to parse hex object IDs in any algorithm
  hex: introduce parsing variants taking hash algorithms
  ...
2020-03-26 17:11:20 -07:00
Derrick Stolee
2d657ab95f pack-objects: flip the use of GIT_TEST_PACK_SPARSE
The environment variable GIT_TEST_PACK_SPARSE was previously used
to allow testing the --sparse option for "git pack-objects" in
the test suite. This allowed interesting cases of "git push" to
also test this algorithm.

Since pack.useSparse is now true by default, we do not need this
variable to _enable_ the --sparse option, but instead to _disable_
it. This flips how we work with the variable a bit.

When checking for the variable, default to a value of -1 for
"unset". If unset, then take the default from the repo settings,
which is currently 1. Then, the --[no-]sparse command-line option
will override either of these settings.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-03-20 14:22:32 -07:00
Junio C Hamano
e8e71848ea Merge branch 'jk/nth-packed-object-id'
Code cleanup to use "struct object_id" more by replacing use of
"char *sha1"

* jk/nth-packed-object-id:
  packfile: drop nth_packed_object_sha1()
  packed_object_info(): use object_id internally for delta base
  packed_object_info(): use object_id for returning delta base
  pack-check: push oid lookup into loop
  pack-check: convert "internal error" die to a BUG()
  pack-bitmap: use object_id when loading on-disk bitmaps
  pack-objects: use object_id struct in pack-reuse code
  pack-objects: convert oe_set_delta_ext() to use object_id
  pack-objects: read delta base oid into object_id struct
  nth_packed_object_oid(): use customary integer return
2020-03-05 10:43:03 -08:00
Junio C Hamano
0df82d99da Merge branch 'jk/object-filter-with-bitmap'
The object reachability bitmap machinery and the partial cloning
machinery were not prepared to work well together, because some
object-filtering criteria that partial clones use inherently rely
on object traversal, but the bitmap machinery is an optimization
to bypass that object traversal.  There however are some cases
where they can work together, and they were taught about them.

* jk/object-filter-with-bitmap:
  rev-list --count: comment on the use of count_right++
  pack-objects: support filters with bitmaps
  pack-bitmap: implement BLOB_LIMIT filtering
  pack-bitmap: implement BLOB_NONE filtering
  bitmap: add bitmap_unset() function
  rev-list: use bitmap filters for traversal
  pack-bitmap: basic noop bitmap filter infrastructure
  rev-list: allow commit-only bitmap traversals
  t5310: factor out bitmap traversal comparison
  rev-list: allow bitmaps when counting objects
  rev-list: make --count work with --objects
  rev-list: factor out bitmap-optimized routines
  pack-bitmap: refuse to do a bitmap traversal with pathspecs
  rev-list: fallback to non-bitmap traversal when filtering
  pack-bitmap: fix leak of haves/wants object lists
  pack-bitmap: factor out type iterator initialization
2020-03-02 15:07:18 -08:00
Jeff King
f66d4e0250 pack-objects: use object_id struct in pack-reuse code
When the pack-reuse code is dumping an OFS_DELTA entry to a client that
doesn't support it, we re-write it as a REF_DELTA. To do so, we use
nth_packed_object_sha1() to get the oid, but that function is soon going
away in favor of the more type-safe nth_packed_object_id(). Let's switch
now in preparation.

Note that this does incur an extra hash copy (from the pack idx mmap to
the object_id and then to the output, rather than straight from mmap to
the output). But this is not worth worrying about. It's probably not
measurable even when it triggers, and this is fallback code that we
expect to trigger very rarely (since everybody supports OFS_DELTA these
days anyway).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-24 12:55:53 -08:00
Jeff King
a93c141dde pack-objects: convert oe_set_delta_ext() to use object_id
We already store an object_id internally, and now our sole caller also
has one. Let's stop passing around the internal hash array, which adds a
bit of type safety.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-24 12:55:52 -08:00
Jeff King
3f83fd5e44 pack-objects: read delta base oid into object_id struct
When we're considering reusing an on-disk delta, we get the oid of the
base as a pointer to unsigned char bytes of the hash, either into the
packfile itself (for REF_DELTA) or into the pack idx (using the revindex
to convert the offset into an index entry).

Instead, we'd prefer to use a more type-safe object_id as much as
possible. We can get the pack idx using nth_packed_object_id() instead.
For the packfile bytes, we can copy them out using oidread().

This doesn't even incur an extra copy overall, since the next thing we'd
always do with that pointer is pass it to can_reuse_delta(), which needs
an object_id anyway (and called oidread() itself). So this patch also
converts that function to take the object_id directly.

Note that we did previously use NULL as a sentinel value when the object
isn't a delta. We could probably get away with using the null oid for
this, but instead we'll use an explicit boolean flag, which should make
things more obvious for people reading the code later.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-24 12:55:52 -08:00