Commit Graph

218 Commits

Author SHA1 Message Date
Elijah Newren
87bed17907 object-file.h: move declarations for object-file.c functions from cache.h
Signed-off-by: Elijah Newren <newren@gmail.com>
Acked-by: Calvin Wan <calvinwan@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-04-11 08:52:10 -07:00
Elijah Newren
f394e093df treewide: be explicit about dependence on gettext.h
Dozens of files made use of gettext functions, without explicitly
including gettext.h.  This made it more difficult to find which files
could remove a dependence on cache.h.  Make C files explicitly include
gettext.h if they are using it.

However, while compat/fsmonitor/fsm-ipc-darwin.c should also gain an
include of gettext.h, it was left out to avoid conflicting with an
in-flight topic.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-21 10:56:51 -07:00
Elijah Newren
41771fa435 cache.h: remove dependence on hex.h; make other files include it explicitly
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-02-23 17:25:29 -08:00
Jeff King
c1166ca0e2 blob: drop unused parts of parse_blob_buffer()
Our parse_blob_buffer() takes a ptr/len combo, just like
parse_tree_buffer(), etc, and returns success or failure. But it doesn't
actually do anything with them; we just set the "parsed" flag in the
object and return success, without even looking at the contents.

There could be some value to keeping these unused parameters:

  - it's consistent with the parse functions for other object types. But
    we already lost that consistency in 837d395a5c (Replace parse_blob()
    with an explanatory comment, 2010-01-18).

  - As the comment from 837d395a5c explains, callers are supposed to
    make sure they have the object content available. So in theory
    asking for these parameters could serve as a signal. But there are
    only two callers, and one of them always passes NULL (after doing a
    streaming check of the object hash).

    This shows that there aren't likely to be a lot of callers (since
    everyone either uses the type-generic parse functions, or handles
    blobs individually), and that they need to take special care anyway
    (because we usually want to avoid loading whole blobs in memory if
    we can avoid it).

So let's just drop these unused parameters, and likewise the useless
return value. While we're touching the header file, let's move the
declaration of parse_blob_buffer() right below that explanatory comment,
where it's more likely to be seen by people looking for the function.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-12-13 22:16:22 +09:00
Ævar Arnfjörð Bjarmason
40286ca2fa parse_object(): simplify blob conditional
Commit 8db2dad7a0 (parse_object(): check on-disk type of suspected blob,
2022-11-17) simplified the conditional for checking if we might have a
blob. But we can simplify it further. In:

  !obj || (obj && obj->type == OBJ_BLOB)

the short-circuit "OR" means "obj" will always be true on the right-hand
side. The compiler almost certainly optimized that out anyway, but
dropping it makes the conditional easier to understand for humans.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-11-22 10:13:54 +09:00
Jeff King
8db2dad7a0 parse_object(): check on-disk type of suspected blob
In parse_object(), we try to handle blobs by streaming rather than
loading them entirely into memory. The most common case here will be
that we haven't seen the object yet and check oid_object_info(), which
tells us we have a blob.

But we trigger this code on one other case: when we have an in-memory
object struct with type OBJ_BLOB (and without its "parsed" flag set,
since otherwise we'd return early from the function). This indicates
that some other part of the code suspected we have a blob (e.g., it was
mentioned by a tree or tag) but we haven't yet looked at the on-disk
copy.

In this case before hitting the streaming path, we check if we have the
object on-disk at all. This is mostly pointless extra work, as the
streaming path would complain if it couldn't open the object (albeit
with the message "hash mismatch", which is a little misleading).

But it's also insufficient to catch all problems. The streaming code
will only tell us "yes, the on-disk object matches the oid". But it
doesn't actually confirm that what we found was indeed a blob, and
neither does repo_has_object_file().

One way to improve this would be to teach stream_object_signature() to
check the type (either by returning it to us to check, or taking an
"expected" type). But there's an even simpler fix here: if we suspect
the object is a blob, just call oid_object_info() to confirm that we
have it on-disk, and that it really is a blob.

This is slightly less efficient than teaching stream_object_signature()
to do it (since it has to open the object already). But this case very
rarely comes up. In practice, we usually don't have any clue what the
type is, in which case we already call oid_object_info(). This
"suspected" case happens only when some other code created an object
struct but didn't actually parse the blob, which is actually tricky to
trigger at all (see the discussion of the test below).

I reworked the conditional a bit so that instead of:

  if ((suspected_blob && oid_object_info() == OBJ_BLOB)
      (no_clue && oid_object_info() == OBJ_BLOB)

we have the simpler:

  if ((suspected_blob || no_clue) && oid_object_info() == OBJ_BLOB)

This is shorter, but also reflects what we really want say, which is
"have we ruled out this being a blob; if not, check it on-disk".

In either case, if oid_object_info() fails to tell us it's a blob, we'll
skip the streaming code path and call repo_read_object_file(), just as
before. And if we really do have a mismatch with the existing object
struct, we'll eventually call lookup_commit(), etc, via
parse_object_buffer(), which will complain that it doesn't match our
existing obj->type.

So this fixes one of the lingering expect_failure cases from 0616617c7e
(t: introduce tests for unexpected object types, 2019-04-09).  That test
works by peeling a tag that claims to point to a blob (triggering us to
create the struct), but really points to something else, which we later
discover when we call parse_object() as part of the actual traversal).
Prior to this commit, we'd quietly check the sha1 and mark the blob as
"parsed". Now we correctly complain about the mismatch.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
2022-11-18 13:59:31 -05:00
Jeff King
04fb96219a parse_object(): drop extra "has" check before checking object type
When parsing an object of unknown type, we check to see if it's a blob,
so we can use our streaming code path. This uses oid_object_info() to
check the type, but before doing so we call repo_has_object_file(). This
latter is pointless, as oid_object_info() will already fail if the
object is missing. Checking it ahead of time just complicates the code
and is a waste of resources (albeit small).

Let's drop the redundant check.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
2022-11-18 13:59:31 -05:00
Junio C Hamano
fdbfac60fd Merge branch 'jk/fsck-on-diet'
"git fsck" failed to release contents of tree objects already used
from the memory, which has been fixed.

* jk/fsck-on-diet:
  parse_object_buffer(): respect save_commit_buffer
  fsck: turn off save_commit_buffer
  fsck: free tree buffers after walking unreachable objects
2022-10-10 10:08:39 -07:00
Jeff King
51b27747e5 parse_object_buffer(): respect save_commit_buffer
If the global variable "save_commit_buffer" is set to 0, then
parse_commit() will throw away the commit object data after parsing it,
rather than sticking it into a commit slab. This goes all the way back
to 60ab26de99 ([PATCH] Avoid wasting memory in git-rev-list,
2005-09-15).

But there's another code path which may similarly stash the buffer:
parse_object_buffer(). This is where we end up if we parse a commit via
parse_object(), and it's used directly in a few other code paths like
git-fsck.

The original goal of 60ab26de99 was avoiding extra memory usage for
rev-list. And there it's not all that important to catch parse_object().
We use that function only for looking at the tips of the traversal, and
the majority of the commits are parsed by following parent links, where
we use parse_commit() directly. So we were wasting some memory, but only
a small portion.

It's much easier to see the effect with fsck. Since we now turn off
save_commit_buffer by default there, we _should_ be able to drop the
freeing of the commit buffer in fsck_obj(). But if we do so (taking the
first hunk of this patch without the rest), then the peak heap of "git
fsck" in a clone of git.git goes from 136MB to 194MB. Teaching
parse_object_buffer() to respect save_commit_buffer brings that down to
134.5MB (it's hard to tell from massif's output, but I suspect the
savings comes from avoiding the overhead of the mostly-empty commit
slab).

Other programs should see a small improvement. Both "rev-list --all" and
"fsck --connectivity-only" improve by a few hundred kilobytes, as they'd
avoid loading the tip objects of their traversals.

Most importantly, no code should be hurt by doing this. Any program that
turns off save_commit_buffer is already making the assumption that any
commit it sees may need to have its object data loaded on demand, as it
doesn't know which ones were parsed by parse_commit() versus
parse_object(). Not to mention that anything parsed by the commit graph
may be in the same boat, even if save_commit_buffer was not disabled.

This should be the only spot that needs to be fixed. Grepping for
set_commit_buffer() shows that this and parse_commit() are the only
relevant calls.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-22 11:40:47 -07:00
Jeff King
9a8c3c4a5f parse_object(): check commit-graph when skip_hash set
If the caller told us that they don't care about us checking the object
hash, then we're free to implement any optimizations that get us the
parsed value more quickly. An obvious one is to check the commit graph
before loading an object from disk. And in fact, both of the callers who
pass in this flag are already doing so before they call parse_object()!

So we can simplify those callers, as well as any possible future ones,
by moving the logic into parse_object().

There are two subtle things to note in the diff, but neither has any
impact in practice:

  - it seems least-surprising here to do the graph lookup on the
    git-replace'd oid, rather than the original. This is in theory a
    change of behavior from the earlier code, as neither caller did a
    replace lookup itself. But in practice it doesn't matter, as we
    disable the commit graph entirely if there are any replace refs.

  - the caller in get_reference() passes the skip_hash flag only if
    revs->verify_objects isn't set, whereas it would look in the commit
    graph unconditionally. In practice this should not matter as we
    should disable the commit graph entirely when using verify_objects
    (and that was done recently in another patch).

So this should be a pure cleanup with no behavior change.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-07 12:27:02 -07:00
Jeff King
c868d8e91f parse_object(): allow skipping hash check
The parse_object() function checks the object hash of any object it
parses. This is a nice feature, as it means we may catch bit corruption
during normal use, rather than waiting for specific fsck operations.

But it also can be slow. It's particularly noticeable for blobs, where
except for the hash check, we could return without loading the object
contents at all. Now one may wonder what is the point of calling
parse_object() on a blob in the first place then, but usually it's not
intentional: we were fed an oid from somewhere, don't know the type, and
want an object struct. For commits and trees, the parsing is usually
helpful; we're about to look at the contents anyway. But this is less
true for blobs, where we may be collecting them as part of a
reachability traversal, etc, and don't actually care what's in them. And
blobs, of course, tend to be larger.

We don't want to just throw out the hash-checks for blobs, though. We do
depend on them in some circumstances (e.g., rev-list --verify-objects
uses parse_object() to check them). It's only the callers that know
how they're going to use the result. And so we can help them by
providing a special flag to skip the hash check.

We could just apply this to blobs, as they're going to be the main
source of performance improvement. But if a caller doesn't care about
checking the hash, we might as well skip it for other object types, too.
Even though we can't avoid reading the object contents, we can still
skip the actual hash computation.

If this seems like it is making Git a little bit less safe against
corruption, it may be. But it's part of a series of tradeoffs we're
already making. For instance, "rev-list --objects" does not open the
contents of blobs it prints. And when a commit graph is present, we skip
opening most commits entirely. The important thing will be to use this
flag in cases where it's safe to skip the check. For instance, when
serving a pack for a fetch, we know the client will fully index the
objects and do a connectivity check itself. There's little to be gained
from the server side re-hashing a blob itself. And indeed, most of the
time we don't! The revision machinery won't open up a blob reached by
traversal, but only one requested directly with a "want" line. So
applied properly, this new feature shouldn't make anything less safe in
practice.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-07 12:18:57 -07:00
Ævar Arnfjörð Bjarmason
44439c1c58 object-file API: have hash_object_file() take "enum object_type"
Change the hash_object_file() function to take an "enum
object_type".

Since a preceding commit all of its callers are passing either
"{commit,tree,blob,tag}_type", or the result of a call to type_name(),
the parse_object() caller that would pass NULL is now using
stream_object_signature().

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-25 17:16:32 -08:00
Ævar Arnfjörð Bjarmason
0f156dbb04 object-file API: split up and simplify check_object_signature()
Split up the check_object_signature() function into that non-streaming
version (it accepts an already filled "buf"), and a new
stream_object_signature() which will retrieve the object from storage,
and hash it on-the-fly.

All of the callers of check_object_signature() were effectively
calling two different functions, if we go by cyclomatic
complexity. I.e. they'd either take the early "if (map)" branch and
return early, or not. This has been the case since the "if (map)"
condition was added in 090ea12671 (parse_object: avoid putting whole
blob in core, 2012-03-07).

We can then further simplify the resulting check_object_signature()
function since only one caller wanted to pass a non-NULL "buf" and a
non-NULL "real_oidp". That "read_loose_object()" codepath used by "git
fsck" can instead use hash_object_file() followed by oideq().

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-25 17:16:31 -08:00
Junio C Hamano
0dc90d954d Merge branch 'ns/tmp-objdir'
New interface into the tmp-objdir API to help in-core use of the
quarantine feature.

* ns/tmp-objdir:
  tmp-objdir: disable ref updates when replacing the primary odb
  tmp-objdir: new API for creating temporary writable databases
2022-01-03 16:24:15 -08:00
Neeraj Singh
b3cecf49ea tmp-objdir: new API for creating temporary writable databases
The tmp_objdir API provides the ability to create temporary object
directories, but was designed with the goal of having subprocesses
access these object stores, followed by the main process migrating
objects from it to the main object store or just deleting it.  The
subprocesses would view it as their primary datastore and write to it.

Here we add the tmp_objdir_replace_primary_odb function that replaces
the current process's writable "main" object directory with the
specified one. The previous main object directory is restored in either
tmp_objdir_migrate or tmp_objdir_destroy.

For the --remerge-diff usecase, add a new `will_destroy` flag in `struct
object_database` to mark ephemeral object databases that do not require
fsync durability.

Add 'git prune' support for removing temporary object databases, and
make sure that they have a name starting with tmp_ and containing an
operation-specific name.

Based-on-patch-by: Elijah Newren <newren@gmail.com>

Signed-off-by: Neeraj Singh <neerajsi@microsoft.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-08 14:06:36 -08:00
Ævar Arnfjörð Bjarmason
eafd6e7e55 object.c: use BUG(...) no die("BUG: ...") in lookup_object_by_type()
Adjust code added in 7463064b28 (object.h: add
lookup_object_by_type() function, 2021-06-22) to use the BUG()
function.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-07 12:33:58 -08:00
Junio C Hamano
061a21d36d Merge branch 'ab/fsck-unexpected-type'
"git fsck" has been taught to report mismatch between expected and
actual types of an object better.

* ab/fsck-unexpected-type:
  fsck: report invalid object type-path combinations
  fsck: don't hard die on invalid object types
  object-file.c: stop dying in parse_loose_header()
  object-file.c: return ULHR_TOO_LONG on "header too long"
  object-file.c: use "enum" return type for unpack_loose_header()
  object-file.c: simplify unpack_loose_short_header()
  object-file.c: make parse_loose_header_extended() public
  object-file.c: return -1, not "status" from unpack_loose_header()
  object-file.c: don't set "typep" when returning non-zero
  cat-file tests: test for current --allow-unknown-type behavior
  cat-file tests: add corrupt loose object test
  cat-file tests: test for missing/bogus object with -t, -s and -p
  cat-file tests: move bogus_* variable declarations earlier
  fsck tests: test for garbage appended to a loose object
  fsck tests: test current hash/type mismatch behavior
  fsck tests: refactor one test to use a sub-repo
  fsck tests: add test for fsck-ing an unknown type
2021-10-25 16:06:56 -07:00
Ævar Arnfjörð Bjarmason
96e41f58fe fsck: report invalid object type-path combinations
Improve the error that's emitted in cases where we find a loose object
we parse, but which isn't at the location we expect it to be.

Before this change we'd prefix the error with a not-a-OID derived from
the path at which the object was found, due to an emergent behavior in
how we'd end up with an "OID" in these codepaths.

Now we'll instead say what object we hashed, and what path it was
found at. Before this patch series e.g.:

    $ git hash-object --stdin -w -t blob </dev/null
    e69de29bb2
    $ mv objects/e6/ objects/e7

Would emit ("[...]" used to abbreviate the OIDs):

    git fsck
    error: hash mismatch for ./objects/e7/9d[...] (expected e79d[...])
    error: e79d[...]: object corrupt or missing: ./objects/e7/9d[...]

Now we'll instead emit:

    error: e69d[...]: hash-path mismatch, found at: ./objects/e7/9d[...]

Furthermore, we'll do the right thing when the object type and its
location are bad. I.e. this case:

    $ git hash-object --stdin -w -t garbage --literally </dev/null
    8315a83d2acc4c174aed59430f9a9c4ed926440f
    $ mv objects/83 objects/84

As noted in an earlier commits we'd simply die early in those cases,
until preceding commits fixed the hard die on invalid object type:

    $ git fsck
    fatal: invalid object type

Now we'll instead emit sensible error messages:

    $ git fsck
    error: 8315[...]: hash-path mismatch, found at: ./objects/84/15[...]
    error: 8315[...]: object is of unknown type 'garbage': ./objects/84/15[...]

In both fsck.c and object-file.c we're using null_oid as a sentinel
value for checking whether we got far enough to be certain that the
issue was indeed this OID mismatch.

We need to add the "object corrupt or missing" special-case to deal
with cases where read_loose_object() will return an error before
completing check_object_signature(), e.g. if we have an error in
unpack_loose_rest() because we find garbage after the valid gzip
content:

    $ git hash-object --stdin -w -t blob </dev/null
    e69de29bb2
    $ chmod 755 objects/e6/9de29bb2d1d6434b8b29ae775ad8c2e48c5391
    $ echo garbage >>objects/e6/9de29bb2d1d6434b8b29ae775ad8c2e48c5391
    $ git fsck
    error: garbage at end of loose object 'e69d[...]'
    error: unable to unpack contents of ./objects/e6/9d[...]
    error: e69d[...]: object corrupt or missing: ./objects/e6/9d[...]

There is currently some weird messaging in the edge case when the two
are combined, i.e. because we're not explicitly passing along an error
state about this specific scenario from check_stream_oid() via
read_loose_object() we'll end up printing the null OID if an object is
of an unknown type *and* it can't be unpacked by zlib, e.g.:

    $ git hash-object --stdin -w -t garbage --literally </dev/null
    8315a83d2acc4c174aed59430f9a9c4ed926440f
    $ chmod 755 objects/83/15a83d2acc4c174aed59430f9a9c4ed926440f
    $ echo garbage >>objects/83/15a83d2acc4c174aed59430f9a9c4ed926440f
    $ /usr/bin/git fsck
    fatal: invalid object type
    $ ~/g/git/git fsck
    error: garbage at end of loose object '8315a83d2acc4c174aed59430f9a9c4ed926440f'
    error: unable to unpack contents of ./objects/83/15a83d2acc4c174aed59430f9a9c4ed926440f
    error: 8315a83d2acc4c174aed59430f9a9c4ed926440f: object corrupt or missing: ./objects/83/15a83d2acc4c174aed59430f9a9c4ed926440f
    error: 0000000000000000000000000000000000000000: object is of unknown type 'garbage': ./objects/83/15a83d2acc4c174aed59430f9a9c4ed926440f
    [...]

I think it's OK to leave that for future improvements, which would
involve enum-ifying more error state as we've done with "enum
unpack_loose_header_result" in preceding commits. In these
increasingly more obscure cases the worst that can happen is that
we'll get slightly nonsensical or inapplicable error messages.

There's other such potential edge cases, all of which might produce
some confusing messaging, but still be handled correctly as far as
passing along errors goes. E.g. if check_object_signature() returns
and oideq(real_oid, null_oid()) is true, which could happen if it
returns -1 due to the read_istream() call having failed.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-01 15:06:01 -07:00
Junio C Hamano
c9d6d8a193 Merge branch 'jk/log-decorate-optim'
Optimize "git log" for cases where we wasted cycles to load ref
decoration data that may not be needed.

* jk/log-decorate-optim:
  load_ref_decorations(): fix decoration with tags
  add_ref_decoration(): rename s/type/deco_type/
  load_ref_decorations(): avoid parsing non-tag objects
  object.h: add lookup_object_by_type() function
  object.h: expand docstring for lookup_unknown_object()
  log: avoid loading decorations for userformats that don't need it
  pretty.h: update and expand docstring for userformat_find_requirements()
2021-07-28 13:17:58 -07:00
Eric Wong
cf2dc1c238 speed up alt_odb_usable() with many alternates
With many alternates, the duplicate check in alt_odb_usable()
wastes many cycles doing repeated fspathcmp() on every existing
alternate.  Use a khash to speed up lookups by odb->path.

Since the kh_put_* API uses the supplied key without
duplicating it, we also take advantage of it to replace both
xstrdup() and strbuf_release() in link_alt_odb_entry() with
strbuf_detach() to avoid the allocation and copy.

In a test repository with 50K alternates and each of those 50K
alternates having one alternate each (for a total of 100K total
alternates); this speeds up lookup of a non-existent blob from
over 16 minutes to roughly 2.7 seconds on my busy workstation.

Note: all underlying git object directories were small and
unpacked with only loose objects and no packs.  Having to load
packs increases times significantly.

Signed-off-by: Eric Wong <e@80x24.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-07 17:21:12 -07:00
Jeff King
7463064b28 object.h: add lookup_object_by_type() function
In some cases it's useful for efficiency reasons to get the type of an
object before deciding whether to parse it, but we still want an object
struct. E.g., in reachable.c, bitmaps give us the type, but we just want
to mark flags on each object. Likewise, we may loop over every object
and only parse tags in order to peel them; checking the type first lets
us avoid parsing the non-tags.

But our lookup_blob(), etc, functions make getting an object struct
annoying: we have to call the right function for every type. And we
cannot just use the generic lookup_object(), because it only returns an
already-seen object; it won't allocate a new object struct.

Let's provide a function that dispatches to the correct lookup_*
function based on a run-time type. In fact, reachable.c already has such
a helper, so we'll just make that public.

I did change the return type from "void *" to "struct object *". While
the former is a clever way to avoid casting inside the function, it's
less safe and less informative to people reading the function
declaration.

The next commit will add a new caller.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-06-28 20:30:18 -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
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
Jiang Xin
ce1d6d9f16 bundle: lost objects when removing duplicate pendings
`git rev-list` will list one commit for the following command:

    $ git rev-list 'main^!'
    <tip-commit-of-main-branch>

But providing the same rev-list args to `git bundle`, fail to create
a bundle file.

    $ git bundle create - 'main^!'
    # v2 git bundle
    -<OID> <one-line-message>

    fatal: Refusing to create empty bundle.

This is because when removing duplicate objects in function
`object_array_remove_duplicates()`, one unique pending object which has
the same name is deleted by mistake.  The revision arg 'main^!' in the
above example is parsed by `handle_revision_arg()`, and at lease two
different objects will be appended to `revs.pending`, one points to the
parent commit of the "main" branch, and the other points to the tip
commit of the "main" branch.  These two objects have the same name
"main".  Only one object is left with the name "main" after calling the
function `object_array_remove_duplicates()`.

And what's worse, when adding boundary commits into pending list, we use
one-line commit message as names, and the arbitory names may surprise
git-bundle.

Only comparing objects themselves (".item") is also not good enough,
because user may want to create a bundle with two identical objects but
with different reference names, such as: "HEAD" and "refs/heads/main".

Add new function `contains_object()` which compare both the address and
the name of the object.

Signed-off-by: Jiang Xin <zhiyou.jx@alibaba-inc.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-11 21:50:41 -08:00
Junio C Hamano
bf0a430f70 Merge branch 'en/strmap'
A specialization of hashmap that uses a string as key has been
introduced.  Hopefully it will see wider use over time.

* en/strmap:
  shortlog: use strset from strmap.h
  Use new HASHMAP_INIT macro to simplify hashmap initialization
  strmap: take advantage of FLEXPTR_ALLOC_STR when relevant
  strmap: enable allocations to come from a mem_pool
  strmap: add a strset sub-type
  strmap: split create_entry() out of strmap_put()
  strmap: add functions facilitating use as a string->int map
  strmap: enable faster clearing and reusing of strmaps
  strmap: add more utility functions
  strmap: new utility functions
  hashmap: provide deallocation function names
  hashmap: introduce a new hashmap_partial_clear()
  hashmap: allow re-use after hashmap_free()
  hashmap: adjust spacing to fix argument alignment
  hashmap: add usage documentation explaining hashmap_free[_entries]()
2020-11-21 15:14:38 -08:00
Elijah Newren
6da1a25814 hashmap: provide deallocation function names
hashmap_free(), hashmap_free_entries(), and hashmap_free_() have existed
for a while, but aren't necessarily the clearest names, especially with
hashmap_partial_clear() being added to the mix and lazy-initialization
now being supported.  Peff suggested we adopt the following names[1]:

  - hashmap_clear() - remove all entries and de-allocate any
    hashmap-specific data, but be ready for reuse

  - hashmap_clear_and_free() - ditto, but free the entries themselves

  - hashmap_partial_clear() - remove all entries but don't deallocate
    table

  - hashmap_partial_clear_and_free() - ditto, but free the entries

This patch provides the new names and converts all existing callers over
to the new naming scheme.

[1] https://lore.kernel.org/git/20201030125059.GA3277724@coredump.intra.peff.net/

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-02 12:15:50 -08:00
René Scharfe
cd8888452c object: allow clear_commit_marks_all to handle any repo
Allow callers to specify the repository to use.  Rename the function to
repo_clear_commit_marks to document its new scope.  No functional change
intended.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-10-31 10:46:34 -07:00
Abhishek Kumar
6da43d937c object: drop parsed_object_pool->commit_count
14ba97f8 (alloc: allow arbitrary repositories for alloc functions,
2018-05-15) introduced parsed_object_pool->commit_count to keep count of
commits per repository and was used to assign commit->index.

However, commit-slab code requires commit->index values to be unique
and a global count would be correct, rather than a per-repo count.

Let's introduce a static counter variable, `parsed_commits_count` to
keep track of parsed commits so far.

As commit_count has no use anymore, let's also drop it from the struct.

Signed-off-by: Abhishek Kumar <abhishekkumar8222@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-06-17 14:37:14 -07:00
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
Junio C Hamano
78e67cda42 Merge branch 'mt/use-passed-repo-more-in-funcs'
Some codepaths were given a repository instance as a parameter to
work in the repository, but passed the_repository instance to its
callees, which has been cleaned up (somewhat).

* mt/use-passed-repo-more-in-funcs:
  sha1-file: allow check_object_signature() to handle any repo
  sha1-file: pass git_hash_algo to hash_object_file()
  sha1-file: pass git_hash_algo to write_object_file_prepare()
  streaming: allow open_istream() to handle any repo
  pack-check: use given repo's hash_algo at verify_packfile()
  cache-tree: use given repo's hash_algo at verify_one()
  diff: make diff_populate_filespec() honor its repo argument
2020-02-14 12:54:22 -08:00
Jeff King
acac50dd8c pack-bitmap: fix leak of haves/wants object lists
When we do a bitmap-aware revision traversal, we create an object_list
for each of the "haves" and "wants" tips. After creating the result
bitmaps these are no longer needed or used, but we never free the list
memory.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-13 09:08:58 -08:00
Matheus Tavares
b98d188581 sha1-file: allow check_object_signature() to handle any repo
Some callers of check_object_signature() can work on arbitrary
repositories, but the repo does not get passed to this function.
Instead, the_repository is always used internally. To fix possible
inconsistencies, allow the function to receive a struct repository and
make those callers pass on the repo being handled.

Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-31 10:45:39 -08:00
Matheus Tavares
b1fc9da1c8 replace-object: make replace operations thread-safe
replace-object functions are very close to being thread-safe: the only
current racy section is the lazy initialization at
prepare_replace_object(). The following patches will protect some object
reading operations to be called threaded, but before that, replace
functions must be protected. To do so, add a mutex to struct
raw_object_store and acquire it before lazy initializing the
replace_map. This won't cause any noticeable performance drop as the
mutex will no longer be used after the replace_map is initialized.

Later, when the replace functions are called in parallel, thread
debuggers might point our use of the added replace_map_initialized flag
as a data race. However, as this boolean variable is initialized as
false and it's only updated once, there's no real harm. It's perfectly
fine if the value is updated right after a thread read it in
replace-map.h:lookup_replace_object() (there'll only be a performance
penalty for the affected threads at that moment). We could cease the
debugger warning protecting the variable reading at the said function.
However, this would negatively affect performance for all threads
calling it, at any time, so it's not really worthy since the warning
doesn't represent a real problem. Instead, to make sure we don't get
false positives (at ThreadSanitizer, at least) an entry for the
respective function is added to .tsan-suppressions.

Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-17 13:52:14 -08:00
Colin Stolley
ec48540fe8 packfile.c: speed up loading lots of packfiles
When loading packfiles on start-up, we traverse the internal packfile
list once per file to avoid reloading packfiles that have already
been loaded. This check runs in quadratic time, so for poorly
maintained repos with a large number of packfiles, it can be pretty
slow.

Add a hashmap containing the packfile names as we load them so that
the average runtime cost of checking for already-loaded packs becomes
constant.

Add a perf test to p5303 to show speed-up.

The existing p5303 test runtimes are dominated by other factors and do
not show an appreciable speed-up. The new test in p5303 clearly exposes
a speed-up in bad cases. In this test we create 10,000 packfiles and
measure the start-up time of git rev-parse, which does little else
besides load in the packs.

Here are the numbers for the new p5303 test:

Test                         HEAD^             HEAD
---------------------------------------------------------------------
5303.12: load 10,000 packs   1.03(0.92+0.10)   0.12(0.02+0.09) -88.3%

Signed-off-by: Colin Stolley <cstolley@runbox.com>
Helped-by: Jeff King <peff@peff.net>
[jc: squashed the change to call hashmap in install_packed_git() by peff]
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-03 07:59:45 -08:00
René Scharfe
2fe44394c8 treewide: remove duplicate #include directives
Found with "git grep '^#include ' '*.c' | sort | uniq -d".

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-04 08:16:00 +09:00
Junio C Hamano
a7db4c193d Merge branch 'jk/oidhash'
Code clean-up to remove hardcoded SHA-1 hash from many places.

* jk/oidhash:
  hashmap: convert sha1hash() to oidhash()
  hash.h: move object_id definition from cache.h
  khash: rename oid helper functions
  khash: drop sha1-specific map types
  pack-bitmap: convert khash_sha1 maps into kh_oid_map
  delta-islands: convert island_marks khash to use oids
  khash: rename kh_oid_t to kh_oid_set
  khash: drop broken oid_map typedef
  object: convert create_object() to use object_id
  object: convert internal hash_obj() to object_id
  object: convert lookup_object() to use object_id
  object: convert lookup_unknown_object() to use object_id
  pack-objects: convert locate_object_entry_hash() to object_id
  pack-objects: convert packlist_find() to use object_id
  pack-bitmap-write: convert some helpers to use object_id
  upload-pack: rename a "sha1" variable to "oid"
  describe: fix accidental oid/hash type-punning
2019-07-09 15:25:43 -07:00
Jeff King
d40abc8e95 hashmap: convert sha1hash() to oidhash()
There are no callers left of sha1hash() that do not simply pass the
"hash" member of a "struct object_id". Let's get rid of the outdated
sha1-specific function and provide one that operates on the whole struct
(even though the technique, taking the first few bytes of the hash, will
remain the same).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-20 10:44:22 -07:00
Jeff King
a378509e1c object: convert create_object() to use object_id
There are no callers left of create_object() that aren't just passing us
the "hash" member of a "struct object_id". Let's take the whole struct,
which gets us closer to removing all raw sha1 variables.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-20 10:20:51 -07:00
Jeff King
46931d3938 object: convert internal hash_obj() to object_id
Now that lookup_object() has an object_id, we can consistently pass that
around instead of a raw sha1. We still convert to a hash to pass to
sha1hash(), but the goal is for that to go away shortly.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-20 10:19:37 -07:00
Jeff King
d0229abd93 object: convert lookup_object() to use object_id
There are no callers left of lookup_object() that aren't just passing us
the "hash" member of a "struct object_id". Let's take the whole struct,
which gets us closer to removing all raw sha1 variables.  It also
matches the existing conversions of lookup_blob(), etc.

The conversions of callers were done by hand, but they're all mechanical
one-liners.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-20 10:18:09 -07:00
Jeff King
0ebbcf70e6 object: convert lookup_unknown_object() to use object_id
There are no callers left of lookup_unknown_object() that aren't just
passing us the "hash" member of a "struct object_id". Let's take the
whole struct, which gets us closer to removing all raw sha1 variables.
It also matches the existing conversions of lookup_blob(), etc.

The conversions of callers were done by hand, but they're all mechanical
one-liners.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-20 10:06:19 -07:00
Derrick Stolee
2d511cfc0b packfile: rename close_all_packs to close_object_store
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>
2019-06-12 11:33:54 -07:00
Josh Steadmon
96b0710ee4 object: fix leak of shallow_stat
In eee4502baa ("shallow: migrate shallow information into the object
parser", 2018-05-17), we added a stat_validity pointer into the
parsed_object_pool struct, but did not add code to free this in
parsed_object_pool_clear(). This leak was found by fuzz-commit-graph.

Clear the struct and then free it in parsed_object_pool_clear() to
prevent the leak.

Signed-off-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-07 13:02:28 -08:00
Junio C Hamano
cba595ab1a Merge branch 'jk/loose-object-cache-oid'
Code clean-up.

* jk/loose-object-cache-oid:
  prefer "hash mismatch" to "sha1 mismatch"
  sha1-file: avoid "sha1 file" for generic use in messages
  sha1-file: prefer "loose object file" to "sha1 file" in messages
  sha1-file: drop has_sha1_file()
  convert has_sha1_file() callers to has_object_file()
  sha1-file: convert pass-through functions to object_id
  sha1-file: modernize loose header/stream functions
  sha1-file: modernize loose object file functions
  http: use struct object_id instead of bare sha1
  update comment references to sha1_object_info()
  sha1-file: fix outdated sha1 comment references
2019-02-06 22:05:27 -08:00
Junio C Hamano
2ed3de439e Merge branch 'sg/object-as-type-commit-graph-fix'
The commit-graph facility did not work when in-core objects that
are promoted from unknown type to commit (e.g. a commit that is
accessed via a tag that refers to it) were involved, which has been
corrected.

* sg/object-as-type-commit-graph-fix:
  object_as_type: initialize commit-graph-related fields of 'struct commit'
2019-02-05 14:26:19 -08:00
Junio C Hamano
b99a579f8e Merge branch 'sb/more-repo-in-api'
The in-core repository instances are passed through more codepaths.

* sb/more-repo-in-api: (23 commits)
  t/helper/test-repository: celebrate independence from the_repository
  path.h: make REPO_GIT_PATH_FUNC repository agnostic
  commit: prepare free_commit_buffer and release_commit_memory for any repo
  commit-graph: convert remaining functions to handle any repo
  submodule: don't add submodule as odb for push
  submodule: use submodule repos for object lookup
  pretty: prepare format_commit_message to handle arbitrary repositories
  commit: prepare logmsg_reencode to handle arbitrary repositories
  commit: prepare repo_unuse_commit_buffer to handle any repo
  commit: prepare get_commit_buffer to handle any repo
  commit-reach: prepare in_merge_bases[_many] to handle any repo
  commit-reach: prepare get_merge_bases to handle any repo
  commit-reach.c: allow get_merge_bases_many_0 to handle any repo
  commit-reach.c: allow remove_redundant to handle any repo
  commit-reach.c: allow merge_bases_many to handle any repo
  commit-reach.c: allow paint_down_to_common to handle any repo
  commit: allow parse_commit* to handle any repo
  object: parse_object to honor its repository argument
  object-store: prepare has_{sha1, object}_file to handle any repo
  object-store: prepare read_object_file to deal with any repo
  ...
2019-02-05 14:26:09 -08:00
SZEDER Gábor
4468d4435c object_as_type: initialize commit-graph-related fields of 'struct commit'
When the commit graph and generation numbers were introduced in
commits 177722b344 (commit: integrate commit graph with commit
parsing, 2018-04-10) and 83073cc994 (commit: add generation number to
struct commit, 2018-04-25), they tried to make sure that the
corresponding 'graph_pos' and 'generation' fields of 'struct commit'
are initialized conservatively, as if the commit were not included in
the commit-graph file.

Alas, initializing those fields only in alloc_commit_node() missed the
case when an object that happens to be a commit is first looked up via
lookup_unknown_object(), and is then later converted to a 'struct
commit' via the object_as_type() helper function (either calling it
directly, or as part of a subsequent lookup_commit() call).
Consequently, both of those fields incorrectly remain set to zero,
which means e.g. that the commit is present in and is the first entry
of the commit-graph file.  This will result in wrong timestamp, parent
and root tree hashes, if such a 'struct commit' instance is later
filled from the commit-graph.

Extract the initialization of 'struct commit's fields from
alloc_commit_node() into a helper function, and call it from
object_as_type() as well, to make sure that it properly initializes
the two commit-graph-related fields, too.  With this helper function
it is hopefully less likely that any new fields added to 'struct
commit' in the future would remain uninitialized.

With this change alloc_commit_index() won't have any remaining callers
outside of 'alloc.c', so mark it as static.

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-27 16:55:57 -08:00
Jeff King
01f8d5948a prefer "hash mismatch" to "sha1 mismatch"
To future-proof ourselves against a change in the hash, let's use the
more generic "hash mismatch" to refer to integrity problems. Note that
we do advertise this exact string in git-fsck(1). However, the message
itself is marked for translation, meaning we do not expect it to be
machine-readable.

While we're touching that documentation, let's also update it for
grammar and clarity.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-08 09:41:06 -08:00
René Scharfe
d4e19e5163 object-store: factor out odb_clear_loose_cache()
Add and use a function for emptying the loose object cache, so callers
don't have to know any of its implementation details.

Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-08 09:40:19 -08:00
Stefan Beller
6a7895fd8a commit: prepare free_commit_buffer and release_commit_memory for any repo
Pass the object pool to free_commit_buffer and release_commit_memory,
such that we can eliminate access to 'the_repository'.

Also remove the TODO in release_commit_memory, as commit->util was
removed in 9d2c97016f (commit.h: delete 'util' field in struct commit,
2018-05-19)

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-12-28 10:06:33 -08:00