Commit Graph

1150 Commits

Author SHA1 Message Date
Junio C Hamano
991b4d47f0 Merge branch 'ps/avoid-unnecessary-hook-invocation-with-packed-refs'
Because a deletion of ref would need to remove it from both the
loose ref store and the packed ref store, a delete-ref operation
that logically removes one ref may end up invoking ref-transaction
hook twice, which has been corrected.

* ps/avoid-unnecessary-hook-invocation-with-packed-refs:
  refs: skip hooks when deleting uncovered packed refs
  refs: do not execute reference-transaction hook on packing refs
  refs: demonstrate excessive execution of the reference-transaction hook
  refs: allow skipping the reference-transaction hook
  refs: allow passing flags when beginning transactions
  refs: extract packed_refs_delete_refs() to allow control of transaction
2022-02-18 13:53:27 -08:00
Patrick Steinhardt
4f2ba2d06a refs: add interface to iterate over queued transactional updates
There is no way for a caller to see whether a reference update has
already been queued up for a given reference transaction. There are
multiple alternatives to provide this functionality:

    - We may add a function that simply tells us whether a specific
      reference has already been queued. If implemented naively then
      this would potentially be quadratic in runtime behaviour if this
      question is asked repeatedly because we have to iterate over all
      references every time. The alternative would be to add a hashmap
      of all queued reference updates to speed up the lookup, but this
      adds overhead to all callers.

    - We may add a flag to `ref_transaction_add_update()` that causes it
      to skip duplicates, but this has the same runtime concerns as the
      first alternative.

    - We may add an interface which lets callers collect all updates
      which have already been queued such that he can avoid re-adding
      them. This is the most flexible approach and puts the burden on
      the caller, but also allows us to not impact any of the existing
      callsites which don't need this information.

This commit implements the last approach: it allows us to compute the
map of already-queued updates once up front such that we can then skip
all subsequent references which are already part of this map.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-17 11:19:44 -08:00
Ævar Arnfjörð Bjarmason
88c7b4c3c8 date API: create a date.h, split from cache.h
Move the declaration of the date.c functions from cache.h, and adjust
the relevant users to include the new date.h header.

The show_ident_date() function belonged in pretty.h (it's defined in
pretty.c), its two users outside of pretty.c didn't strictly need to
include pretty.h, as they get it indirectly, but let's add it to them
anyway.

Similarly, the change to "builtin/{fast-import,show-branch,tag}.c"
isn't needed as far as the compiler is concerned, but since they all
use the "DATE_MODE()" macro we now define in date.h, let's have them
include it.

We could simply include this new header in "cache.h", but as this
change shows these functions weren't common enough to warrant
including in it in the first place. By moving them out of cache.h
changes to this API will no longer cause a (mostly) full re-build of
the project when "make" is run.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-16 09:40:00 -08:00
Ævar Arnfjörð Bjarmason
ce14de03db refs API: remove "failure_errno" from refs_resolve_ref_unsafe()
Remove the now-unused "failure_errno" parameter from the
refs_resolve_ref_unsafe() signature. In my recent 96f6623ada (Merge
branch 'ab/refs-errno-cleanup', 2021-11-29) series we made all of its
callers explicitly request the errno via an output parameter.

As that series shows all but one caller ended up passing in a
boilerplate "ignore_errno", since they only cared about whether the
return value was NULL or not, i.e. if the ref could be resolved.

There was one small issue with that series fixed with a follow-up in
31e3912369 (Merge branch 'ab/refs-errno-cleanup', 2022-01-14) a small
bug in that series was fixed.

After those two there was one caller left in sequencer.c that used the
"failure_errno', but as of the preceding commit it uses a boilerplate
"ignore_errno" instead.

This leaves the public refs API without any use of "failure_errno" at
all. We could still do with a bit of cleanup and generalization
between refs.c and refs/files-backend.c before the "reftable"
integration lands, but that's all internal to the reference code
itself.

So let's remove this output parameter. Not only isn't it used now, but
it's unlikely that we'll want it again in the future. We'd like to
slowly move the refs API to a more file-backend independent way of
communicating error codes, having it use a "failure_errno" was only
the first step in that direction. If this or any other function needs
to communicate what specifically is wrong with the requested "refname"
it'll be better to have the function set some output enum of
well-defined error states than piggy-backend on "errno".

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-26 15:58:41 -08:00
Patrick Steinhardt
958fbc74e3 refs: allow skipping the reference-transaction hook
The reference-transaction hook is executing whenever we prepare, commit
or abort a reference transaction. While this is mostly intentional, in
case of the files backend we're leaking the implementation detail that
the store is in fact a composite store with one loose and one packed
backend to the caller. So while we want to execute the hook for all
logical updates, executing it for such implementation details is
unexpected.

Prepare for a fix by adding a new flag which allows to skip execution of
the hook.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-17 11:01:45 -08:00
Patrick Steinhardt
fbe73f61cb refs: allow passing flags when beginning transactions
We do not currently have any flags when creating reference transactions,
but we'll add one to disable execution of the reference transaction hook
in some cases.

Allow passing flags to `ref_store_transaction_begin()` to prepare for
this change.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-17 11:01:44 -08:00
Junio C Hamano
31e3912369 Merge branch 'ab/refs-errno-cleanup'
A brown-paper-bag fix on top of a topic that was merged during this
cycle.

* ab/refs-errno-cleanup:
  refs API: use "failure_errno", not "errno"
2022-01-14 15:25:15 -08:00
Ævar Arnfjörð Bjarmason
cac15b3fb4 refs API: use "failure_errno", not "errno"
Fix a logic error in refs_resolve_ref_unsafe() introduced in a recent
series of mine to abstract the refs API away from errno. See
96f6623ada (Merge branch 'ab/refs-errno-cleanup', 2021-11-29)for that
series.

In that series introduction of "failure_errno" to
refs_resolve_ref_unsafe came in ef18119dec (refs API: add a version
of refs_resolve_ref_unsafe() with "errno", 2021-10-16). There we'd set
"errno = 0" immediately before refs_read_raw_ref(), and then set
"failure_errno" to "errno" if errno was non-zero afterwards.

Then in the next commit 8b72fea7e9 (refs API: make
refs_read_raw_ref() not set errno, 2021-10-16) we started expecting
"refs_read_raw_ref()" to set "failure_errno". It would do that if
refs_read_raw_ref() failed, but it wouldn't be the same errno.

So we might set the "errno" here to any arbitrary bad value, and end
up e.g. returning NULL when we meant to return the refname from
refs_resolve_ref_unsafe(), or the other way around. Instrumenting this
code will reveal cases where refs_read_raw_ref() will fail, and
"errno" and "failure_errno" will be set to different values.

In practice I haven't found a case where this scary bug changed
anything in practice. The reason for that is that we'll not care about
the actual value of "errno" here per-se, but only whether:

 1. We have an errno
 2. If it's one of ENOENT, EISDIR or ENOTDIR. See the adjacent code
    added in a1c1d8170d (refs_resolve_ref_unsafe: handle d/f
    conflicts for writes, 2017-10-06)

I.e. if we clobber "failure_errno" with "errno", but it happened to be
one of those three, and we'll clobber it with another one of the three
we were OK.

Perhaps there are cases where the difference ended up mattering, but I
haven't found them. Instrumenting the test suite to fail if "errno"
and "failure_errno" are different shows a lot of failures, checking if
they're different *and* one is but not the other is outside that list
of three "errno" values yields no failures.

But let's fix the obvious bug. We should just stop paying attention to
"errno" in refs_resolve_ref_unsafe(). In addition let's change the
partial resetting of "errno" in files_read_raw_ref() to happen just
before the "return", to ensure that any such bug will be more easily
spotted in the future.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-13 10:53:54 -08:00
Junio C Hamano
01ea04f76e Merge branch 'hn/refs-debug-update'
Debugging support for refs API.

* hn/refs-debug-update:
  refs: centralize initialization of the base ref_store.
  refs: print error message in debug output
  refs: pass gitdir to packed_ref_store_create
2022-01-10 11:52:51 -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
Han-Wen Nienhuys
f9f7fd3b23 refs: centralize initialization of the base ref_store.
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-22 13:51:38 -08:00
Junio C Hamano
b174a3c014 Merge branch 'hn/allow-bogus-oid-in-ref-tests'
The test helper for refs subsystem learned to write bogus and/or
nonexistent object name to refs to simulate error situations we
want to test Git in.

* hn/allow-bogus-oid-in-ref-tests:
  t1430: create valid symrefs using test-helper
  t1430: remove refs using test-tool
  refs: introduce REF_SKIP_REFNAME_VERIFICATION flag
  refs: introduce REF_SKIP_OID_VERIFICATION flag
  refs: update comment.
  test-ref-store: plug memory leak in cmd_delete_refs
  test-ref-store: parse symbolic flag constants
  test-ref-store: remove force-create argument for create-reflog
2021-12-15 09:39:54 -08:00
Junio C Hamano
b8148376a2 Merge branch 'hn/create-reflog-simplify'
A small simplification of API.

* hn/create-reflog-simplify:
  refs: drop force_create argument of create_reflog API
2021-12-10 14:35:13 -08:00
Junio C Hamano
8bb6fe853f Merge branch 'jk/refs-g11-workaround'
Workaround for a false-alarm by gcc-11

* jk/refs-g11-workaround:
  refs: work around gcc-11 warning with REF_HAVE_NEW
2021-12-10 14:35:12 -08:00
Neeraj Singh
ecd81dfc79 tmp-objdir: disable ref updates when replacing the primary odb
When creating a subprocess with a temporary ODB, we set the
GIT_QUARANTINE_ENVIRONMENT env var to tell child Git processes not
to update refs, since the tmp-objdir may go away.

Introduce a similar mechanism for in-process temporary ODBs when
we call tmp_objdir_replace_primary_odb. Now both mechanisms set
the disable_ref_updates flag on the odb, which is queried by
the ref_transaction_prepare function.

Peff's test case [1] was invoking ref updates via the cachetextconv
setting. That particular code silently does nothing when a ref
update is forbidden. See the call to notes_cache_put in
fill_textconv where errors are ignored.

[1] https://lore.kernel.org/git/YVOn3hDsb5pnxR53@coredump.intra.peff.net/

Reported-by: Jeff King <peff@peff.net>
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 14:06:46 -08:00
Han-Wen Nienhuys
3c966c7b4e refs: introduce REF_SKIP_REFNAME_VERIFICATION flag
Use this flag with the test-helper in t1430, to avoid direct writes to the ref
database.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-07 13:15:19 -08:00
Junio C Hamano
96f6623ada Merge branch 'ab/refs-errno-cleanup'
The "remainder" of hn/refs-errno-cleanup topic.

* ab/refs-errno-cleanup: (21 commits)
  refs API: post-migration API renaming [2/2]
  refs API: post-migration API renaming [1/2]
  refs API: don't expose "errno" in run_transaction_hook()
  refs API: make expand_ref() & repo_dwim_log() not set errno
  refs API: make resolve_ref_unsafe() not set errno
  refs API: make refs_ref_exists() not set errno
  refs API: make refs_resolve_refdup() not set errno
  refs tests: ignore ignore errno in test-ref-store helper
  refs API: ignore errno in worktree.c's find_shared_symref()
  refs API: ignore errno in worktree.c's add_head_info()
  refs API: make files_copy_or_rename_ref() et al not set errno
  refs API: make loose_fill_ref_dir() not set errno
  refs API: make resolve_gitlink_ref() not set errno
  refs API: remove refs_read_ref_full() wrapper
  refs/files: remove "name exist?" check in lock_ref_oid_basic()
  reflog tests: add --updateref tests
  refs API: make refs_rename_ref_available() static
  refs API: make parse_loose_ref_contents() not set errno
  refs API: make refs_read_raw_ref() not set errno
  refs API: add a version of refs_resolve_ref_unsafe() with "errno"
  ...
2021-11-29 15:41:45 -08:00
Han-Wen Nienhuys
7b089120d9 refs: drop force_create argument of create_reflog API
There is only one caller, builtin/checkout.c, and it hardcodes
force_create=1.

This argument was introduced in abd0cd3a30 (refs: new public ref function:
safe_create_reflog, 2015-07-21), which promised to immediately use it in a
follow-on commit, but that never happened.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-11-22 11:01:25 -08:00
Jeff King
49f1eb3b34 refs: work around gcc-11 warning with REF_HAVE_NEW
Using gcc-11 (or 12) to compile refs.o with -O3 results in:

  In file included from hashmap.h:4,
                   from cache.h:6,
                   from refs.c:5:
  In function ‘oidcpy’,
      inlined from ‘ref_transaction_add_update’ at refs.c:1065:3,
      inlined from ‘ref_transaction_update’ at refs.c:1094:2,
      inlined from ‘ref_transaction_verify’ at refs.c:1132:9:
  hash.h:262:9: warning: argument 2 null where non-null expected [-Wnonnull]
    262 |         memcpy(dst->hash, src->hash, GIT_MAX_RAWSZ);
        |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  In file included from git-compat-util.h:177,
                   from cache.h:4,
                   from refs.c:5:
  refs.c: In function ‘ref_transaction_verify’:
  /usr/include/string.h:43:14: note: in a call to function ‘memcpy’ declared ‘nonnull’
     43 | extern void *memcpy (void *__restrict __dest, const void *__restrict __src,
        |              ^~~~~~

That call to memcpy() is in a conditional block that requires
REF_HAVE_NEW to be set. But in ref_transaction_update(), we make sure it
isn't set coming in:

  if (flags & ~REF_TRANSACTION_UPDATE_ALLOWED_FLAGS)
          BUG("illegal flags 0x%x passed to ref_transaction_update()", flags);

and then only set it if the variable isn't NULL:

  flags |= (new_oid ? REF_HAVE_NEW : 0) | (old_oid ? REF_HAVE_OLD : 0);

So it should be impossible to reach that memcpy() with a NULL oid. But
for whatever reason, gcc doesn't accept that hitting the BUG() means we
won't go any further, even though it's marked with the noreturn
attribute. And the conditional is correct; ALLOWED_FLAGS doesn't contain
HAVE_NEW or HAVE_OLD, and you can even simplify it to check for those
flags explicitly and the compiler still complains.

We can work around this by just clearing the disallowed flags
explicitly. This should be a noop because of the BUG() check, but it
makes the compiler happy.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-11-19 13:50:23 -08:00
Junio C Hamano
162a13b855 Merge branch 'jt/no-abuse-alternate-odb-for-submodules'
Follow through the work to use the repo interface to access
submodule objects in-process, instead of abusing the alternate
object database interface.

* jt/no-abuse-alternate-odb-for-submodules:
  submodule: trace adding submodule ODB as alternate
  submodule: pass repo to check_has_commit()
  object-file: only register submodule ODB if needed
  merge-{ort,recursive}: remove add_submodule_odb()
  refs: peeling non-the_repository iterators is BUG
  refs: teach arbitrary repo support to iterators
  refs: plumb repo into ref stores
2021-10-25 16:06:56 -07:00
Ævar Arnfjörð Bjarmason
f1da24ca5e refs API: post-migration API renaming [2/2]
Rename the transitory refs_werrres_ref_unsafe() function to
refs_resolve_ref_unsafe(), now that all callers of the old function
have learned to pass in a "failure_errno" parameter.

The coccinelle semantic patch added in the preceding commit works, but
I couldn't figure out how to get spatch(1) to re-flow these argument
lists (and sometimes make lines way too long), so this rename was done
with:

    perl -pi -e 's/refs_werrres_ref_unsafe/refs_resolve_ref_unsafe/g' \
    $(git grep -l refs_werrres_ref_unsafe -- '*.c')

But after that "make contrib/coccinelle/refs.cocci.patch" comes up
empty, so the result would have been the same. Let's remove that
transitory semantic patch file, we won't need to retain it for any
other in-flight changes, refs_werrres_ref_unsafe() only existed within
this patch series.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-16 11:17:04 -07:00
Ævar Arnfjörð Bjarmason
25a33b3342 refs API: post-migration API renaming [1/2]
In preceding commits all callers of refs_resolve_ref_unsafe() were
migrated to the transitory refs_werrres_ref_unsafe() function.

As a first step in getting rid of it let's remove the old function
from the public API (it went unused in a preceding commit).

We then provide both a coccinelle rule to do the rename, and a macro
to avoid breaking the existing callers.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-16 11:17:04 -07:00
Ævar Arnfjörð Bjarmason
4755d7dff7 refs API: don't expose "errno" in run_transaction_hook()
In run_transaction_hook() we've checked errno since 6754159767 (refs:
implement reference transaction hook, 2020-06-19), let's reset errno
afterwards to make sure nobody using refs.c directly or indirectly
relies on it.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-16 11:17:04 -07:00
Ævar Arnfjörð Bjarmason
6582bd31e3 refs API: make expand_ref() & repo_dwim_log() not set errno
The use of these two is rather trivial, and it's easy to see none of
their callers care about errno. So let's move them from
refs_resolve_ref_unsafe() to refs_resolve_ref_unsafe_with_errno(),
these were the last two callers, so we can get rid of that wrapper
function.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-16 11:17:04 -07:00
Ævar Arnfjörð Bjarmason
ed90f04155 refs API: make resolve_ref_unsafe() not set errno
Change the resolve_ref_unsafe() wrapper function to use the underlying
refs_werrres_ref_unsafe() directly.

From a reading of the callers I determined that the only one who cared
about errno was a sequencer.c caller added in e47c6cafcb (commit:
move print_commit_summary() to libgit, 2017-11-24), I'm migrating it
to using refs_werrres_ref_unsafe() directly.

This adds another "set errno" instance, but in this case it's OK and
idiomatic. We are setting it just before calling die_errno(). We could
have some hypothetical die_errno_var(&saved_errno, ...) here, but I
don't think it's worth it. The problem with errno is subtle action at
distance, not this sort of thing. We already use this pattern in a
couple of places in wrapper.c

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-16 11:17:04 -07:00
Ævar Arnfjörð Bjarmason
1e3ccb552f refs API: make refs_ref_exists() not set errno
Move refs_ref_exists from the legacy refs_resolve_ref_unsafe() to the
new refs_werrres_ref_unsafe(). I have read its callers and determined
that they don't care about errno being set, in particular:

    git grep -W -w -e refs_ref_exists -e ref_exists

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-16 11:17:04 -07:00
Ævar Arnfjörð Bjarmason
f65bb9fb06 refs API: make refs_resolve_refdup() not set errno
Move refs_resolve_refdup() from the legacy refs_resolve_ref_unsafe()
to the new refs_werrres_ref_unsafe(). I have read its callers and
determined that they don't care about errno being set.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-16 11:17:03 -07:00
Ævar Arnfjörð Bjarmason
db7a3d25d6 refs API: make resolve_gitlink_ref() not set errno
I have carefully read the upstream callers of resolve_gitlink_ref()
and determined that they don't care about errno.

So let's move away from the errno-setting refs_resolve_ref_unsafe()
wrapper to refs_werrres_ref_unsafe(), and explicitly ignore the errno
it sets for us.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-16 11:17:03 -07:00
Ævar Arnfjörð Bjarmason
76887df014 refs API: remove refs_read_ref_full() wrapper
Remove the refs_read_ref_full() wrapper in favor of migrating various
refs.c API users to the underlying refs_werrres_ref_unsafe() function.

A careful reading of these callers shows that the callers of this
function did not care about "errno", by moving away from the
refs_resolve_ref_unsafe() wrapper we can be sure that nothing relies
on it anymore.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-16 11:17:03 -07:00
Ævar Arnfjörð Bjarmason
c339ff690f refs API: make refs_rename_ref_available() static
Move the refs_rename_ref_available() function into
"refs/files-backend.c". It is file-backend specific.

This function was added in 5fe7d825da (refs.c: pass a list of names
to skip to is_refname_available, 2014-05-01) as rename_ref_available()
and was only ever used in this one file-backend specific codepath. So
let's move it there.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-16 11:17:02 -07:00
Han-Wen Nienhuys
df3458e957 refs API: make parse_loose_ref_contents() not set errno
Change the parse_loose_ref_contents() function to stop setting "errno"
and failure, and to instead pass up a "failure_errno" via a
parameter. This requires changing its callers to do the same.

The EINVAL error from parse_loose_ref_contents is used in files-backend
to create a custom error message.

In untangling this we discovered a tricky edge case. The
refs_read_special_head() function was relying on
parse_loose_ref_contents() setting EINVAL.

By converting it to use "saved_errno" we can migrate away from "errno"
in this part of the code entirely, and do away with an existing
"save_errno" pattern, its only purpose was to not clobber the "errno"
we previously needed at the end of files_read_raw_ref().

Let's assert that we can do that by not having files_read_raw_ref()
itself operate on *failure_errno in addition to passing it on. Instead
we'll assert that if we return non-zero we actually do set errno, thus
assuring ourselves and callers that they can trust the resulting
"failure_errno".

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-16 11:17:02 -07:00
Han-Wen Nienhuys
8b72fea7e9 refs API: make refs_read_raw_ref() not set errno
Add a "failure_errno" to refs_read_raw_ref(), his allows
refs_werrres_ref_unsafe() to pass along its "failure_errno", as a
first step before its own callers are migrated to pass it further up
the chain.

We are leaving out out the refs_read_special_head() in
refs_read_raw_ref() for now, as noted in a subsequent commit moving it
to "failure_errno" will require some special consideration.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-16 11:17:02 -07:00
Ævar Arnfjörð Bjarmason
ef18119dec refs API: add a version of refs_resolve_ref_unsafe() with "errno"
Add a new refs_werrres_ref_unsafe() function, which is like
refs_resolve_ref_unsafe() except that it explicitly saves away the
"errno" to a passed-in parameter, the refs_resolve_ref_unsafe() then
becomes a wrapper for it.

In subsequent commits we'll migrate code over to it, before finally
making "refs_resolve_ref_unsafe()" with an "errno" parameter the
canonical version, so this this function exists only so that we can
incrementally migrate callers, it will be going away in a subsequent
commit.

As the added comment notes has a rather tortured name to be the same
length as "refs_resolve_ref_unsafe", to avoid churn as we won't need
to re-indent the argument lists, similarly the documentation and
structure of it in refs.h is designed to minimize a diff in a
subsequent commit, where that documentation will be added to the new
refs_resolve_ref_unsafe().

At the end of this migration the "meaningful errno" TODO item left in
76d70dc0c6 (refs.c: make resolve_ref_unsafe set errno to something
meaningful on error, 2014-06-20) will be resolved.

As can be seen from the use of refs_read_raw_ref() we'll also need to
convert some functions that the new refs_werrres_ref_unsafe() itself
calls to take this "failure_errno". That will be done in subsequent
commits.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-16 11:17:02 -07:00
Junio C Hamano
a5e61a4225 Merge branch 'ab/config-based-hooks-1'
Mostly preliminary clean-up in the hook API.

* ab/config-based-hooks-1:
  hook-list.h: add a generated list of hooks, like config-list.h
  hook.c users: use "hook_exists()" instead of "find_hook()"
  hook.c: add a hook_exists() wrapper and use it in bugreport.c
  hook.[ch]: move find_hook() from run-command.c to hook.c
  Makefile: remove an out-of-date comment
  Makefile: don't perform "mv $@+ $@" dance for $(GENERATED_H)
  Makefile: stop hardcoding {command,config}-list.h
  Makefile: mark "check" target as .PHONY
2021-10-13 15:15:57 -07:00
Junio C Hamano
f6c075ad71 Merge branch 'jk/ref-paranoia'
The ref iteration code used to optionally allow dangling refs to be
shown, which has been tightened up.

* jk/ref-paranoia:
  refs: drop "broken" flag from for_each_fullref_in()
  ref-filter: drop broken-ref code entirely
  ref-filter: stop setting FILTER_REFS_INCLUDE_BROKEN
  repack, prune: drop GIT_REF_PARANOIA settings
  refs: turn on GIT_REF_PARANOIA by default
  refs: omit dangling symrefs when using GIT_REF_PARANOIA
  refs: add DO_FOR_EACH_OMIT_DANGLING_SYMREFS flag
  refs-internal.h: reorganize DO_FOR_EACH_* flag documentation
  refs-internal.h: move DO_FOR_EACH_* flags next to each other
  t5312: be more assertive about command failure
  t5312: test non-destructive repack
  t5312: create bogus ref as necessary
  t5312: drop "verbose" helper
  t5600: provide detached HEAD for corruption failures
  t5516: don't use HEAD ref for invalid ref-deletion tests
  t7900: clean up some more broken refs
2021-10-11 10:21:47 -07:00
Jonathan Tan
9bc45a2802 refs: teach arbitrary repo support to iterators
Note that should_pack_ref() is called when writing refs, which is only
supported for the_repository, hence the_repository is hardcoded there.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-08 15:06:05 -07:00
Jonathan Tan
34224e14d6 refs: plumb repo into ref stores
In preparation for the next 2 patches that adds (partial) support for
arbitrary repositories to ref iterators, plumb a repository into all ref
stores. There are no changes to program logic.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-08 15:06:05 -07:00
Junio C Hamano
870de59af0 Merge branch 'ab/retire-refs-unused-funcs'
Code cleanup.

* ab/retire-refs-unused-funcs:
  refs/ref-cache.[ch]: remove "incomplete" from create_dir_entry()
  refs/ref-cache.c: remove "mkdir" parameter from find_containing_dir()
  refs/ref-cache.[ch]: remove unused add_ref_entry()
  refs/ref-cache.[ch]: remove unused remove_entry_from_dir()
  refs.[ch]: remove unused ref_storage_backend_exists()
2021-10-06 13:40:13 -07:00
Ævar Arnfjörð Bjarmason
98961e42f0 refs.[ch]: remove unused ref_storage_backend_exists()
This function was added in 3dce444f17 (refs: add a backend method
structure, 2016-09-04), but has never been used by anything. The only
caller that might care uses find_ref_storage_backend() directly.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-28 15:12:04 -07:00
Jeff King
67985e4e4a refs: drop "broken" flag from for_each_fullref_in()
No callers pass in anything but "0" here. Likewise to our sibling
functions. Note that some of them ferry along the flag, but none of
their callers pass anything but "0" either.

Nor is anybody likely to change that. Callers which really want to see
all of the raw refs use for_each_rawref(). And anybody interested in
iterating a subset of the refs will likely be happy to use the
now-default behavior of showing broken refs, but omitting dangling
symlinks.

So we can get rid of this whole feature.

Signed-off-by: Jeff King <peff@peff.net>
Reviewed-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-27 12:36:45 -07:00
Jeff King
5d1f5b8cd4 repack, prune: drop GIT_REF_PARANOIA settings
Now that GIT_REF_PARANOIA is the default, we don't need to selectively
enable it for destructive operations. In fact, it's harmful to do so,
because it overrides any GIT_REF_PARANOIA=0 setting that the user may
have provided (because they're trying to work around some corruption).

With these uses gone, we can further clean up the ref_paranoia global,
and make it a static variable inside the refs code.

Signed-off-by: Jeff King <peff@peff.net>
Reviewed-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-27 12:36:45 -07:00
Jeff King
968f12fdac refs: turn on GIT_REF_PARANOIA by default
The original point of the GIT_REF_PARANOIA flag was to include broken
refs in iterations, so that possibly-destructive operations would not
silently ignore them (and would generally instead try to operate on the
oids and fail when the objects could not be accessed).

We already turned this on by default for some dangerous operations, like
"repack -ad" (where missing a reachability tip would mean dropping the
associated history). But it was not on for general use, even though it
could easily result in the spreading of corruption (e.g., imagine
cloning a repository which simply omits some of its refs because
their objects are missing; the result quietly succeeds even though you
did not clone everything!).

This patch turns on GIT_REF_PARANOIA by default. So a clone as mentioned
above would actually fail (upload-pack tells us about the broken ref,
and when we ask for the objects, pack-objects fails to deliver them).
This may be inconvenient when working with a corrupted repository, but:

  - we are better off to err on the side of complaining about
    corruption, and then provide mechanisms for explicitly loosening
    safety.

  - this is only one type of corruption anyway. If we are missing any
    other objects in the history that _aren't_ ref tips, then we'd
    behave similarly (happily show the ref, but then barf when we
    started traversing).

We retain the GIT_REF_PARANOIA variable, but simply default it to "1"
instead of "0". That gives the user an escape hatch for loosening this
when working with a corrupt repository. It won't work across a remote
connection to upload-pack (because we can't necessarily set environment
variables on the remote), but there the client has other options (e.g.,
choosing which refs to fetch).

As a bonus, this also makes ref iteration faster in general (because we
don't have to call has_object_file() for each ref), though probably not
noticeably so in the general case. In a repo with a million refs, it
shaved a few hundred milliseconds off of upload-pack's advertisement;
that's noticeable, but most repos are not nearly that large.

The possible downside here is that any operation which iterates refs but
doesn't ever open their objects may now quietly claim to have X when the
object is corrupted (e.g., "git rev-list new-branch --not --all" will
treat a broken ref as uninteresting). But again, that's not really any
different than corruption below the ref level. We might have
refs/heads/old-branch as non-corrupt, but we are not actively checking
that we have the entire reachable history. Or the pointed-to object
could even be corrupted on-disk (but our "do we have it" check would
still succeed). In that sense, this is merely bringing ref-corruption in
line with general object corruption.

One alternative implementation would be to actually check for broken
refs, and then _immediately die_ if we see any. That would cause the
"rev-list --not --all" case above to abort immediately. But in many ways
that's the worst of all worlds:

  - it still spends time looking up the objects an extra time

  - it still doesn't catch corruption below the ref level

  - it's even more inconvenient; with the current implementation of
    GIT_REF_PARANOIA for something like upload-pack, we can make
    the advertisement and let the client choose a non-broken piece of
    history. If we bail as soon as we see a broken ref, they cannot even
    see the advertisement.

The test changes here show some of the fallout. A non-destructive "git
repack -adk" now fails by default (but we can override it). Deleting a
broken ref now actually tells the hooks the correct "before" state,
rather than a confusing null oid.

Signed-off-by: Jeff King <peff@peff.net>
Reviewed-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-27 12:36:45 -07:00
Jeff King
6d751be4b6 refs: omit dangling symrefs when using GIT_REF_PARANOIA
Dangling symrefs aren't actually a corruption problem. It's perfectly
fine for refs/remotes/origin/HEAD to point to an unborn branch. And in
particular, if you are trying to establish reachability, a symref that
points nowhere doesn't matter either way. Any ref it could point to will
be examined during the rest of the traversal.

It's possible that a symref pointing nowhere _could_ be a sign that the
ref it was meant to point to was deleted accidentally (e.g., via
corruption). But there is no particular reason to think that is true for
any given case, and in the meantime, GIT_REF_PARANOIA kicking in
automatically for some operations means they'll fail unnecessarily.

So let's loosen it just a bit. The new test in t5312 shows off an
example that is safe, but currently fails (and no longer does after this
patch).

Note that we don't do anything if the caller explicitly asked for
DO_FOR_EACH_INCLUDE_BROKEN. In that case they may be looking for
dangling symrefs themselves, and setting GIT_REF_PARANOIA should not
_loosen_ things from what the caller asked for.

Signed-off-by: Jeff King <peff@peff.net>
Reviewed-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-27 12:36:45 -07:00
Jeff King
9aab952e85 refs-internal.h: reorganize DO_FOR_EACH_* flag documentation
The documentation for the DO_FOR_EACH_* flags is sprinkled over the
refs-internal.h file. We define the two flags in one spot, and then
describe them in more detail far away from there, in the definitions of
refs_ref_iterator_begin() and ref_iterator_advance_fn().

Let's try to organize this a bit better:

  - convert the #defines to an enum. This makes it clear that they are
    related, and that the enum shows the complete set of flags.

  - combine all descriptions for each flag in a single spot, next to the
    flag's definition

  - use the enum rather than a bare int for functions which take the
    flags. This helps readers realize which flags can be used.

  - clarify the mention of flags for ref_iterator_advance_fn(). It does
    not take flags itself, but is meant to depend on ones set up
    earlier.

Signed-off-by: Jeff King <peff@peff.net>
Reviewed-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-27 12:36:45 -07:00
Ævar Arnfjörð Bjarmason
5e3aba33da hook.[ch]: move find_hook() from run-command.c to hook.c
Move the find_hook() function from run-command.c to a new hook.c
library. This change establishes a stub library that's pretty
pointless right now, but will see much wider use with Emily Shaffer's
upcoming "configuration-based hooks" series.

Eventually all the hook related code will live in hook.[ch]. Let's
start that process by moving the simple find_hook() function over
as-is.

Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-27 09:44:54 -07:00
Han-Wen Nienhuys
5b12e16bb1 refs: make errno output explicit for read_raw_ref_fn
This makes it explicit how alternative ref backends should report errors in
read_raw_ref_fn.

read_raw_ref_fn needs to supply a credible errno for a number of cases. These
are primarily:

1) The files backend calls read_raw_ref from lock_raw_ref, and uses the
resulting error codes to create/remove directories as needed.

2) ENOENT should be translated in a zero OID, optionally with REF_ISBROKEN set,
returning the last successfully resolved symref. This is necessary so
read_raw_ref("HEAD") on an empty repo returns refs/heads/main (or the default branch
du-jour), and we know on which branch to create the first commit.

Make this information flow explicit by adding a failure_errno to the signature
of read_raw_ref. All errnos from the files backend are still propagated
unchanged, even though inspection suggests only ENOTDIR, EISDIR and ENOENT are
relevant.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-08-25 13:30:26 -07:00
Ævar Arnfjörð Bjarmason
cc40b5ce13 refs API: remove OID argument to reflog_expire()
Since the the preceding commit the "oid" parameter to reflog_expire()
is always NULL, but it was not cleaned up to reduce the size of the
diff. Let's do that subsequent API and documentation cleanup now.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-08-25 13:27:37 -07:00
Ævar Arnfjörð Bjarmason
6f45ec88d2 refs: make repo_dwim_log() accept a NULL oid
Change the repo_dwim_log() function initially added as dwim_log() in
eb3a48221f (log --reflog: use dwim_log, 2007-02-09) to accept a NULL
oid parameter. The refs_resolve_ref_unsafe() function it invokes
already deals with it, but it didn't.

This allows for a bit more clarity in a reflog-walk.c codepath added
in f2eba66d4d (Enable HEAD@{...} and make it independent from the
current branch, 2007-02-03). We'll shortly use this in
builtin/reflog.c as well.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-08-25 13:27:37 -07:00
Junio C Hamano
f0ade787ac Merge branch 'hn/refs-iterator-peel-returns-boolean'
Tiny API tweak.

* hn/refs-iterator-peel-returns-boolean:
  refs: make explicit that ref_iterator_peel returns boolean
2021-07-16 17:42:49 -07:00
Han-Wen Nienhuys
617480d75b refs: make explicit that ref_iterator_peel returns boolean
Use -1 as error return value throughout.

This removes spurious differences in the GIT_TRACE_REFS output, depending on the
ref storage backend active.

Before, the cached ref_iterator (but only that iterator!) would return
peel_object() output directly. No callers relied on the peel_status values
beyond success/failure. All calls to these functions go through
peel_iterated_oid(), which returns peel_object() as a fallback, but also
squashing the error values.

The iteration interface already passes REF_ISSYMREF and REF_ISBROKEN through the
flags argument, so the additional error values in enum peel_status provide no
value.

The ref iteration interface provides a separate peel() function because certain
formats (eg. packed-refs and reftable) can store the peeled object next to the
tag SHA1. Passing the peeled SHA1 as an optional argument to each_ref_fn maps
more naturally to the implementation of ref databases. Changing the code in this
way is left for a future refactoring.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-05-20 07:54:12 +09:00
Junio C Hamano
aaa3c8065d Merge branch 'bc/hash-transition-interop-part-1'
SHA-256 transition.

* bc/hash-transition-interop-part-1:
  hex: print objects using the hash algorithm member
  hex: default to the_hash_algo on zero algorithm value
  builtin/pack-objects: avoid using struct object_id for pack hash
  commit-graph: don't store file hashes as struct object_id
  builtin/show-index: set the algorithm for object IDs
  hash: provide per-algorithm null OIDs
  hash: set, copy, and use algo field in struct object_id
  builtin/pack-redundant: avoid casting buffers to struct object_id
  Use the final_oid_fn to finalize hashing of object IDs
  hash: add a function to finalize object IDs
  http-push: set algorithm when reading object ID
  Always use oidread to read into struct object_id
  hash: add an algo member to struct object_id
2021-05-10 16:59:46 +09:00
brian m. carlson
14228447c9 hash: provide per-algorithm null OIDs
Up until recently, object IDs did not have an algorithm member, only a
hash.  Consequently, it was possible to share one null (all-zeros)
object ID among all hash algorithms.  Now that we're going to be
handling objects from multiple hash algorithms, it's important to make
sure that all object IDs have a correct algorithm field.

Introduce a per-algorithm null OID, and add it to struct hash_algo.
Introduce a wrapper function as well, and use it everywhere we used to
use the null_oid constant.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-27 16:31:39 +09:00
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
Junio C Hamano
6254fa1359 Merge branch 'tb/ls-refs-optim'
The ls-refs protocol operation has been optimized to narrow the
sub-hierarchy of refs/ it walks to produce response.

* tb/ls-refs-optim:
  ls-refs.c: traverse prefixes of disjoint "ref-prefix" sets
  ls-refs.c: initialize 'prefixes' before using it
  refs: expose 'for_each_fullref_in_prefixes'
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
16b1985be5 refs: expose 'for_each_fullref_in_prefixes'
This function was used in the ref-filter.c code to find the longest
common prefix of among a set of refspecs, and then to iterate all of the
references that descend from that prefix.

A future patch will want to use that same code from ls-refs.c, so
prepare by exposing and moving it to refs.c. Since there is nothing
specific to the ref-filter code here (other than that it was previously
the only caller of this function), this really belongs in the more
generic refs.h header.

The code moved in this patch is identical before and after, with the one
exception of renaming some arguments to be consistent with other
functions exposed in refs.h.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-22 18:57:27 -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
Denton Liu
6436a20284 refs: allow @{n} to work with n-sized reflog
This sequence works

	$ git checkout -b newbranch
	$ git commit --allow-empty -m one
	$ git show -s newbranch@{1}

and shows the state that was immediately after the newbranch was
created.

But then if you do

	$ git reflog expire --expire=now refs/heads/newbranch
	$ git commit --allow=empty -m two
	$ git show -s newbranch@{1}

you'd be scolded with

	fatal: log for 'newbranch' only has 1 entries

While it is true that it has only 1 entry, we have enough
information in that single entry that records the transition between
the state in which the tip of the branch was pointing at commit
'one' to the new commit 'two' built on it, so we should be able to
answer "what object newbranch was pointing at?". But we refuse to
do so.

Make @{0} the special case where we use the new side to look up that
entry. Otherwise, look up @{n} using the old side of the (n-1)th entry
of the reflog.

Suggested-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-11 14:13:50 -08:00
Denton Liu
95c2a71820 refs: factor out set_read_ref_cutoffs()
This block of code is duplicated twice. In a future commit, it will be
duplicated for a third time. Factor out the common functionality into
set_read_ref_cutoffs().

In the case of read_ref_at_ent(), we are incrementing `cb->reccnt` at the
beginning of the function. Move these to right before the return so that
the `cb->reccnt - 1` is changed to `cb->reccnt` and it can be cleanly
factored out into set_read_ref_cutoffs(). The duplication of the
increment statements will be removed in a future patch.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-10 12:24:00 -08:00
Johannes Schindelin
675704c74d init: provide useful advice about init.defaultBranch
To give ample warning for users wishing to override Git's the fall-back
for an unconfigured `init.defaultBranch` (in case we decide to change it
in a future Git version), let's introduce some advice that is shown upon
`git init` when that value is not set.

Note: two test cases in Git's test suite want to verify that the
`stderr` output of `git init` is empty. It is now necessary to suppress
the advice, we now do that via the `init.defaultBranch` setting. While
not strictly necessary, we also set this to `false` in
`test_create_repo()`.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-13 15:53:51 -08:00
Johannes Schindelin
cc0f13c57d get_default_branch_name(): prepare for showing some advice
We are about to introduce a message giving users running `git init` some
advice about `init.defaultBranch`. This will necessarily be done in
`repo_default_branch_name()`.

Not all code paths want to show that advice, though. In particular, the
`git clone` codepath _specifically_ asks for `init_db()` to be quiet,
via the `INIT_DB_QUIET` flag.

In preparation for showing users above-mentioned advice, let's change
the function signature of `get_default_branch_name()` to accept the
parameter `quiet`.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-13 15:53:50 -08:00
Johannes Schindelin
704fed9ea2 tests: start moving to a different default main branch name
To allow for an incremental conversion to a new default main branch
name, let's introduce `GIT_TEST_DEFAULT_MAIN_BRANCH_NAME`. This
environment variable can be set at the top of each converted test
script, overriding the default main branch name to use when initializing
new repositories (or cloning empty repositories).

Note: the `GIT_TEST_DEFAULT_MAIN_BRANCH_NAME` is _not_ intended to be
used manually; many tests require a specific main branch name and cannot
simply work with another one. This `GIT_TEST_*` variable is meant purely
for the transitional period while the entire test suite is converted to
use `main` as the initial branch name by default.

We also introduce the `PREPARE_FOR_MAIN_BRANCH` prereq that determines
whether the default main branch name is `main`, and adjust a couple of
test functions to use it. This prereq will be used to temporarily
disable a couple test cases to allow for adjusting the test script
incrementally. Once an entire test is adjusted, we will adjust the test
so that it is run with `GIT_TEST_DEFAULT_MAIN_BRANCH_NAME=main`.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-10-23 08:57:40 -07:00
Junio C Hamano
c9a04f036f Merge branch 'hn/refs-trace-backend'
Developer support.

* hn/refs-trace-backend:
  refs: add GIT_TRACE_REFS debugging mechanism
2020-09-22 12:36:28 -07:00
Junio C Hamano
0df670bc0b Merge branch 'jt/interpret-branch-name-fallback'
"git status" has trouble showing where it came from by interpreting
reflog entries that recordcertain events, e.g. "checkout @{u}", and
gives a hard/fatal error.  Even though it inherently is impossible
to give a correct answer because the reflog entries lose some
information (e.g. "@{u}" does not record what branch the user was
on hence which branch 'the upstream' needs to be computed, and even
if the record were available, the relationship between branches may
have changed), at least hide the error to allow "status" show its
output.

* jt/interpret-branch-name-fallback:
  wt-status: tolerate dangling marks
  refs: move dwim_ref() to header file
  sha1-name: replace unsigned int with option struct
2020-09-09 13:53:09 -07:00
Han-Wen Nienhuys
4441f42707 refs: add GIT_TRACE_REFS debugging mechanism
When set in the environment, GIT_TRACE_REFS makes git print operations and
results as they flow through the ref storage backend. This helps debug
discrepancies between different ref backends.

Example:

    $ GIT_TRACE_REFS="1" ./git branch
    15:42:09.769631 refs/debug.c:26         ref_store for .git
    15:42:09.769681 refs/debug.c:249        read_raw_ref: HEAD: 0000000000000000000000000000000000000000 (=> refs/heads/ref-debug) type 1: 0
    15:42:09.769695 refs/debug.c:249        read_raw_ref: refs/heads/ref-debug: 3a238e539b (=> refs/heads/ref-debug) type 0: 0
    15:42:09.770282 refs/debug.c:233        ref_iterator_begin: refs/heads/ (0x1)
    15:42:09.770290 refs/debug.c:189        iterator_advance: refs/heads/b4 (0)
    15:42:09.770295 refs/debug.c:189        iterator_advance: refs/heads/branch3 (0)

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-09 12:58:37 -07:00
Jonathan Tan
f24c30e0b6 wt-status: tolerate dangling marks
When a user checks out the upstream branch of HEAD, the upstream branch
not being a local branch, and then runs "git status", like this:

  git clone $URL client
  cd client
  git checkout @{u}
  git status

no status is printed, but instead an error message:

  fatal: HEAD does not point to a branch

(This error message when running "git branch" persists even after
checking out other things - it only stops after checking out a branch.)

This is because "git status" reads the reflog when determining the "HEAD
detached" message, and thus attempts to DWIM "@{u}", but that doesn't
work because HEAD no longer points to a branch.

Therefore, when calculating the status of a worktree, tolerate dangling
marks. This is done by adding an additional parameter to
dwim_ref() and repo_dwim_ref().

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-02 14:39:25 -07:00
Jonathan Tan
ec06b05568 refs: move dwim_ref() to header file
This makes it clear that dwim_ref() is just repo_dwim_ref() without the
first parameter.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-02 14:39:17 -07:00
Jonathan Tan
a4f66a7876 sha1-name: replace unsigned int with option struct
In preparation for a future patch adding a boolean parameter to
repo_interpret_branch_name(), which might be easily confused with an
existing unsigned int parameter, refactor repo_interpret_branch_name()
to take an option struct instead of the unsigned int parameter.

The static function interpret_branch_mark() is also updated to take the
option struct in preparation for that future patch, since it will also
make use of the to-be-introduced boolean parameter.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-02 14:39:17 -07:00
Junio C Hamano
6ddd76fd6c Merge branch 'ps/ref-transaction-hook'
Code simplification by removing ineffective optimization.

* ps/ref-transaction-hook:
  refs: remove lookup cache for reference-transaction hook
2020-08-31 15:49:53 -07:00
Junio C Hamano
e699684cf6 Merge branch 'hn/refs-pseudorefs'
Accesses to two pseudorefs have been updated to properly use ref
API.

* hn/refs-pseudorefs:
  sequencer: treat REVERT_HEAD as a pseudo ref
  builtin/commit: suggest update-ref for pseudoref removal
  sequencer: treat CHERRY_PICK_HEAD as a pseudo ref
  refs: make refs_ref_exists public
2020-08-31 15:49:48 -07:00
Junio C Hamano
98df75b286 Merge branch 'hn/refs-fetch-head-is-special'
The FETCH_HEAD is now always read from the filesystem regardless of
the ref backend in use, as its format is much richer than the
normal refs, and written directly by "git fetch" as a plain file..

* hn/refs-fetch-head-is-special:
  refs: read FETCH_HEAD and MERGE_HEAD generically
  refs: move gitdir into base ref_store
  refs: fix comment about submodule ref_stores
  refs: split off reading loose ref data in separate function
2020-08-27 14:04:49 -07:00
Patrick Steinhardt
0a0fbbe3ff refs: remove lookup cache for reference-transaction hook
When adding the reference-transaction hook, there were concerns about
the performance impact it may have on setups which do not make use of
the new hook at all. After all, it gets executed every time a reftx is
prepared, committed or aborted, which linearly scales with the number of
reference-transactions created per session. And as there are code paths
like `git push` which create a new transaction for each reference to be
updated, this may translate to calling `find_hook()` quite a lot.

To address this concern, a cache was added with the intention to not
repeatedly do negative hook lookups. Turns out this cache caused a
regression, which was fixed via e5256c82e5 (refs: fix interleaving hook
calls with reference-transaction hook, 2020-08-07). In the process of
discussing the fix, we realized that the cache doesn't really help even
in the negative-lookup case. While performance tests added to benchmark
this did show a slight improvement in the 1% range, this really doesn't
warrent having a cache. Furthermore, it's quite flaky, too. E.g. running
it twice in succession produces the following results:

Test                         master            pks-reftx-hook-remove-cache
--------------------------------------------------------------------------
1400.2: update-ref           2.79(2.16+0.74)   2.73(2.12+0.71) -2.2%
1400.3: update-ref --stdin   0.22(0.08+0.14)   0.21(0.08+0.12) -4.5%

Test                         master            pks-reftx-hook-remove-cache
--------------------------------------------------------------------------
1400.2: update-ref           2.70(2.09+0.72)   2.74(2.13+0.71) +1.5%
1400.3: update-ref --stdin   0.21(0.10+0.10)   0.21(0.08+0.13) +0.0%

One case notably absent from those benchmarks is a single executable
searching for the hook hundreds of times, which is exactly the case for
which the negative cache was added. p1400.2 will spawn a new update-ref
for each transaction and p1400.3 only has a single reference-transaction
for all reference updates. So this commit adds a third benchmark, which
performs an non-atomic push of a thousand references. This will create a
new reference transaction per reference. But even for this case, the
negative cache doesn't consistently improve performance:

Test                         master            pks-reftx-hook-remove-cache
--------------------------------------------------------------------------
1400.4: nonatomic push       6.63(6.50+0.13)   6.81(6.67+0.14) +2.7%
1400.4: nonatomic push       6.35(6.21+0.14)   6.39(6.23+0.16) +0.6%
1400.4: nonatomic push       6.43(6.31+0.13)   6.42(6.28+0.15) -0.2%

So let's just remove the cache altogether to simplify the code.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-25 15:34:42 -07:00
Han-Wen Nienhuys
3f9f1acccf refs: make refs_ref_exists public
This will be necessary to replace file existence checks for pseudorefs.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-21 11:20:10 -07:00
Han-Wen Nienhuys
e811530278 refs: read FETCH_HEAD and MERGE_HEAD generically
The FETCH_HEAD and MERGE_HEAD refs must be stored in a file, regardless of the
type of ref backend. This is because they can hold more than just a single ref.

To accomodate them for alternate ref backends, read them from a file generically
in refs_read_raw_ref()

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-19 14:08:04 -07:00
Junio C Hamano
95c687bf85 Merge branch 'hn/reftable-prep-part-2'
Further preliminary change to refs API.

* hn/reftable-prep-part-2:
  Make HEAD a PSEUDOREF rather than PER_WORKTREE.
  Modify pseudo refs through ref backend storage
  t1400: use git rev-parse for testing PSEUDOREF existence
2020-08-17 17:02:42 -07:00
Junio C Hamano
5676db2612 Merge branch 'ps/ref-transaction-hook'
The logic to find the ref transaction hook script attempted to
cache the path to the found hook without realizing that it needed
to keep a copied value, as the API it used returned a transitory
buffer space.  This has been corrected.

* ps/ref-transaction-hook:
  t1416: avoid hard-coded sha1 ids
  refs: fix interleaving hook calls with reference-transaction hook
2020-08-17 17:02:41 -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
Patrick Steinhardt
e5256c82e5 refs: fix interleaving hook calls with reference-transaction hook
In order to not repeatedly search for the reference-transaction hook in
case it's getting called multiple times, we use a caching mechanism to
only call `find_hook()` once. What was missed though is that the return
value of `find_hook()` actually comes from a static strbuf, which means
it will get overwritten when calling `find_hook()` again. As a result,
we may call the wrong hook with parameters of the reference-transaction
hook.

This scenario was spotted in the wild when executing a git-push(1) with
multiple references, where there are interleaving calls to both the
update and the reference-transaction hook. While initial calls to the
reference-transaction hook work as expected, it will stop working after
the next invocation of the update hook. The result is that we now start
calling the update hook with parameters and stdin of the
reference-transaction hook.

This commit fixes the issue by storing a copy of `find_hook()`'s return
value in the cache.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-07 12:27:41 -07:00
Junio C Hamano
dc3c6fb565 Merge branch 'hn/reftable' into master
Brown-paper-bag fix.

* hn/reftable:
  refs: move the logic to add \t to reflog to the files backend
2020-08-01 13:49:13 -07:00
Han-Wen Nienhuys
25429fed5c refs: move the logic to add \t to reflog to the files backend
523fa69c (reflog: cleanse messages in the refs.c layer, 2020-07-10)
centralized reflog normalizaton.  However, the normalizaton added a
leading "\t" to the message. This is an artifact of the reflog
storage format in the files backend, so it should be added there.

Routines that parse back the reflog (such as grab_nth_branch_switch)
expect the "\t" to not be in the message, so without this fix, git
with reftable cannot process the "@{-1}" syntax.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-31 10:21:51 -07:00
Junio C Hamano
3161cc6e6b Merge branch 'hn/reftable' into master
Preliminary clean-up of the refs API in preparation for adding a
new refs backend "reftable".

* hn/reftable:
  reflog: cleanse messages in the refs.c layer
  bisect: treat BISECT_HEAD as a pseudo ref
  t3432: use git-reflog to inspect the reflog for HEAD
  lib-t6000.sh: write tag using git-update-ref
2020-07-30 13:20:32 -07:00
Jeff King
c972bf4cf5 strvec: convert remaining 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 remaining files, as the resulting diff is
reasonably sized.

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;
  '

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
Han-Wen Nienhuys
55dd8b9108 Make HEAD a PSEUDOREF rather than PER_WORKTREE.
This is consistent with the definition of REF_TYPE_PSEUDOREF
(uppercase in the root ref namespace).

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-27 10:06:49 -07:00
Han-Wen Nienhuys
09743417a2 Modify pseudo refs through ref backend storage
The previous behavior was introduced in commit 74ec19d4be
("pseudorefs: create and use pseudoref update and delete functions",
Jul 31, 2015), with the justification "alternate ref backends still
need to store pseudorefs in GIT_DIR".

Refs such as REBASE_HEAD are read through the ref backend. This can
only work consistently if they are written through the ref backend as
well. Tooling that works directly on files under .git should be
updated to use git commands to read refs instead.

The following behaviors change:

* Updates to pseudorefs (eg. ORIG_HEAD) with
  core.logAllRefUpdates=always will create reflogs for the pseudoref.

* non-HEAD pseudoref symrefs are also dereferenced on deletion. Update
  t1405 accordingly.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-27 10:06:49 -07:00
Junio C Hamano
523fa69c36 reflog: cleanse messages in the refs.c layer
Regarding reflog messages:

 - We expect that a reflog message consists of a single line.  The
   file format used by the files backend may add a LF after the
   message as a delimiter, and output by commands like "git log -g"
   may complete such an incomplete line by adding a LF at the end,
   but philosophically, the terminating LF is not a part of the
   message.

 - We however allow callers of refs API to supply a random sequence
   of NUL terminated bytes.  We cleanse caller-supplied message by
   squashing a run of whitespaces into a SP, and by trimming trailing
   whitespace, before storing the message.  This is how we tolerate,
   instead of erring out, a message with LF in it (be it at the end,
   in the middle, or both).

Currently, the cleansing of the reflog message is done by the files
backend, before the log is written out.  This is sufficient with the
current code, as that is the only backend that writes reflogs.  But
new backends can be added that write reflogs, and we'd want the
resulting log message we would read out of "log -g" the same no
matter what backend is used, and moving the code to do so to the
generic layer is a way to do so.

An added benefit is that the "cleansing" function could be updated
later, independent from individual backends, to e.g. allow
multi-line log messages if we wanted to, and when that happens, it
would help a lot to ensure we covered all bases if the cleansing
function (which would be updated) is called from the generic layer.

Side note: I am not interested in supporting multi-line reflog
messages right at the moment (nobody is asking for it), but I
envision that instead of the "squash a run of whitespaces into a SP
and rtrim" cleansing, we can %urlencode problematic bytes in the
message *AND* append a SP at the end, when a new version of Git that
supports multi-line and/or verbatim reflog messages writes a reflog
record.  The reading side can detect the presense of SP at the end
(which should have been rtrimmed out if it were written by existing
versions of Git) as a signal that decoding %urlencode recovers the
original reflog message.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-10 13:53:37 -07:00
Junio C Hamano
11cbda2add Merge branch 'js/default-branch-name'
The name of the primary branch in existing repositories, and the
default name used for the first branch in newly created
repositories, is made configurable, so that we can eventually wean
ourselves off of the hardcoded 'master'.

* js/default-branch-name:
  contrib: subtree: adjust test to change in fmt-merge-msg
  testsvn: respect `init.defaultBranch`
  remote: use the configured default branch name when appropriate
  clone: use configured default branch name when appropriate
  init: allow setting the default for the initial branch name via the config
  init: allow specifying the initial branch name for the new repository
  docs: add missing diamond brackets
  submodule: fall back to remote's HEAD for missing remote.<name>.branch
  send-pack/transport-helper: avoid mentioning a particular branch
  fmt-merge-msg: stop treating `master` specially
2020-07-06 22:09:17 -07:00
Junio C Hamano
d80bea479d Merge branch 'ak/commit-graph-to-slab'
A few fields in "struct commit" that do not have to always be
present have been moved to commit slabs.

* ak/commit-graph-to-slab:
  commit-graph: minimize commit_graph_data_slab access
  commit: move members graph_pos, generation to a slab
  commit-graph: introduce commit_graph_data_slab
  object: drop parsed_object_pool->commit_count
2020-07-06 22:09:14 -07:00
Don Goodman-Wilson
8747ebb7cd init: allow setting the default for the initial branch name via the config
We just introduced the command-line option
`--initial-branch=<branch-name>` to allow initializing a new repository
with a different initial branch than the hard-coded one.

To allow users to override the initial branch name more permanently
(i.e. without having to specify the name manually for each and every
`git init` invocation), let's introduce the `init.defaultBranch` config
setting.

Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Helped-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Don Goodman-Wilson <don@goodman-wilson.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-06-24 09:14:21 -07:00
Patrick Steinhardt
6754159767 refs: implement reference transaction hook
The low-level reference transactions used to update references are
currently completely opaque to the user. While certainly desirable in
most usecases, there are some which might want to hook into the
transaction to observe all queued reference updates as well as observing
the abortion or commit of a prepared transaction.

One such usecase would be to have a set of replicas of a given Git
repository, where we perform Git operations on all of the repositories
at once and expect the outcome to be the same in all of them. While
there exist hooks already for a certain subset of Git commands that
could be used to implement a voting mechanism for this, many others
currently don't have any mechanism for this.

The above scenario is the motivation for the new "reference-transaction"
hook that reaches directly into Git's reference transaction mechanism.
The hook receives as parameter the current state the transaction was
moved to ("prepared", "committed" or "aborted") and gets via its
standard input all queued reference updates. While the exit code gets
ignored in the "committed" and "aborted" states, a non-zero exit code in
the "prepared" state will cause the transaction to be aborted
prematurely.

Given the usecase described above, a voting mechanism can now be
implemented via this hook: as soon as it gets called, it will take all
of stdin and use it to cast a vote to a central service. When all
replicas of the repository agree, the hook will exit with zero,
otherwise it will abort the transaction by returning non-zero. The most
important upside is that this will catch _all_ commands writing
references at once, allowing to implement strong consistency for
reference updates via a single mechanism.

In order to test the impact on the case where we don't have any
"reference-transaction" hook installed in the repository, this commit
introduce two new performance tests for git-update-refs(1). Run against
an empty repository, it produces the following results:

  Test                         origin/master     HEAD
  --------------------------------------------------------------------
  1400.2: update-ref           2.70(2.10+0.71)   2.71(2.10+0.73) +0.4%
  1400.3: update-ref --stdin   0.21(0.09+0.11)   0.21(0.07+0.14) +0.0%

The performance test p1400.2 creates, updates and deletes a branch a
thousand times, thus averaging runtime of git-update-refs over 3000
invocations. p1400.3 instead calls `git-update-refs --stdin` three times
and queues a thousand creations, updates and deletes respectively.

As expected, p1400.3 consistently shows no noticeable impact, as for
each batch of updates there's a single call to access(3P) for the
negative hook lookup. On the other hand, for p1400.2, one can see an
impact caused by this patchset. But doing five runs of the performance
tests where each one was run with GIT_PERF_REPEAT_COUNT=10, the overhead
ranged from -1.5% to +1.1%. These inconsistent performance numbers can
be explained by the overhead of spawning 3000 processes. This shows that
the overhead of assembling the hook path and executing access(3P) once
to check if it's there is mostly outweighed by the operating system's
overhead.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-06-19 10:46:13 -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
d3fc8dc53a Merge branch 'ds/log-exclude-decoration-config'
The "--decorate-refs" and "--decorate-refs-exclude" options "git
log" takes have learned a companion configuration variable
log.excludeDecoration that sits at the lowest priority in the
family.

* ds/log-exclude-decoration-config:
  log: add log.excludeDecoration config option
  log-tree: make ref_filter_match() a helper method
2020-04-28 15:50:08 -07:00
Junio C Hamano
95ca48973d Merge branch 'jc/missing-ref-store-fix'
We've left the command line parsing of "git log :/a/b/" broken for
about a full year without anybody noticing, which has been
corrected.

* jc/missing-ref-store-fix:
  repository: mark the "refs" pointer as private
  sha1-name: do not assume that the ref store is initialized
2020-04-22 13:42:55 -07:00
Derrick Stolee
c9f7a793e8 log-tree: make ref_filter_match() a helper method
The ref_filter_match() method is defined in refs.h and implemented
in refs.c, but is only used by add_ref_decoration() in log-tree.c.
Move it into that file as a static helper method. The
match_ref_pattern() comes along for the ride.

While moving the code, also make a slight adjustment to have
ref_filter_match() take a struct decoration_filter pointer instead
of multiple string lists. This is non-functional, but will make a
later change be much cleaner.

The diff is easier to parse when using the --color-moved option.

Reported-by: Junio C Hamano <gister@pobox.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-16 11:04:55 -07:00
Jeff King
0220461071 repository: mark the "refs" pointer as private
The "refs" pointer in a struct repository starts life as NULL, but then
is lazily initialized when it is accessed via get_main_ref_store().
However, it's easy for calling code to forget this and access it
directly, leading to code which works _some_ of the time, but fails if
it is called before anybody else accesses the refs.

This was the cause of the bug fixed by 5ff4b920eb (sha1-name: do not
assume that the ref store is initialized, 2020-04-09). In order to
prevent similar bugs, let's more clearly mark the "refs" field as
private.

In addition to helping future code, the name change will help us audit
any existing direct uses. Besides get_main_ref_store() itself, it turns
out there is only one. But we know it's OK as it is on the line directly
after the fix from 5ff4b920eb, which will have initialized the pointer.
However it's still a good idea for it to model the proper use of the
accessing function, so we'll convert it.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-09 22:40:48 -07:00
Eric Wong
e2b5038d87 hashmap_entry: remove first member requirement from docs
Comments stating that "struct hashmap_entry" must be the first
member in a struct are no longer valid.

Suggested-by: Phillip Wood <phillip.wood123@gmail.com>
Signed-off-by: Eric Wong <e@80x24.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-07 10:20:12 +09:00
Eric Wong
939af16eac hashmap_cmp_fn takes hashmap_entry params
Another step in eliminating the requirement of hashmap_entry
being the first member of a struct.

Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-07 10:20:11 +09:00
Eric Wong
f23a465132 hashmap_get{,_from_hash} return "struct hashmap_entry *"
Update callers to use hashmap_get_entry, hashmap_get_entry_from_hash
or container_of as appropriate.

This is another step towards eliminating the requirement of
hashmap_entry being the first field in a struct.

Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-07 10:20:11 +09:00
Eric Wong
26b455f21e hashmap_put takes "struct hashmap_entry *"
This is less error-prone than "void *" as the compiler now
detects invalid types being passed.

Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-07 10:20:10 +09:00
Eric Wong
d22245a2e3 hashmap_entry_init takes "struct hashmap_entry *"
C compilers do type checking to make life easier for us.  So
rely on that and update all hashmap_entry_init callers to take
"struct hashmap_entry *" to avoid future bugs while improving
safety and readability.

Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-07 10:20:09 +09:00
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
Junio C Hamano
0d107b1989 Merge branch 'nd/worktree-name-sanitization'
In recent versions of Git, per-worktree refs are exposed in
refs/worktrees/<wtname>/ hierarchy, which means that worktree names
must be a valid refname component.  The code now sanitizes the names
given to worktrees, to make sure these refs are well-formed.

* nd/worktree-name-sanitization:
  worktree add: sanitize worktree names
2019-06-13 13:19:40 -07:00
Nguyễn Thái Ngọc Duy
1de16aecf5 worktree add: sanitize worktree names
Worktree names are based on $(basename $GIT_WORK_TREE). They aren't
significant until 3a3b9d8cde (refs: new ref types to make per-worktree
refs visible to all worktrees - 2018-10-21), where worktree name could
be part of a refname and must follow refname rules.

Update 'worktree add' code to remove special characters to follow
these rules. In the future the user will be able to specify the
worktree name by themselves if they're not happy with this dumb
character substitution.

Reported-by: Konstantin Kharlamov <hi-angel@yandex.ru>
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-05-15 13:56:43 +09:00
Nguyễn Thái Ngọc Duy
7fdff47432 refs.c: remove the_repo from read_ref_at()
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-04-08 17:26:33 +09:00
Nguyễn Thái Ngọc Duy
567009033f refs.c: add repo_dwim_log()
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-04-08 17:26:33 +09:00
Nguyễn Thái Ngọc Duy
d8984c532a refs.c: add repo_dwim_ref()
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-04-08 17:26:33 +09:00
Nguyễn Thái Ngọc Duy
0b1dbf53df refs.c: remove the_repo from expand_ref()
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-04-08 17:26:33 +09:00
Nguyễn Thái Ngọc Duy
8f56e9d4ba refs.c: remove the_repo from substitute_branch_name()
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-04-08 17:26:32 +09:00
Nguyễn Thái Ngọc Duy
546edf37ae refs.c: add refs_shorten_unambiguous_ref()
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-04-08 17:26:32 +09:00
Nguyễn Thái Ngọc Duy
b3cd33d079 refs.c: add refs_ref_exists()
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-04-08 17:26:32 +09:00
Jeff King
98374a07c9 convert has_sha1_file() callers to has_object_file()
The only remaining callers of has_sha1_file() actually have an object_id
already. They can use the "object" variant, rather than dereferencing
the hash themselves.

The code changes here were completely generated by the included
coccinelle patch.

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
Junio C Hamano
c72431ffc9 Merge branch 'ra/rev-parse-exclude-glob'
"rev-parse --exclude=<pattern> --branches=<pattern>" etc. did not
quite work, which has been corrected.

* ra/rev-parse-exclude-glob:
  refs: fix some exclude patterns being ignored
  refs: show --exclude failure with --branches/tags/remotes=glob
2018-11-18 18:23:56 +09:00
Junio C Hamano
e146cc97be Merge branch 'nd/per-worktree-ref-iteration'
The code to traverse objects for reachability, used to decide what
objects are unreferenced and expendable, have been taught to also
consider per-worktree refs of other worktrees as starting points to
prevent data loss.

* nd/per-worktree-ref-iteration:
  git-worktree.txt: correct linkgit command name
  reflog expire: cover reflog from all worktrees
  fsck: check HEAD and reflog from other worktrees
  fsck: move fsck_head_link() to get_default_heads() to avoid some globals
  revision.c: better error reporting on ref from different worktrees
  revision.c: correct a parameter name
  refs: new ref types to make per-worktree refs visible to all worktrees
  Add a place for (not) sharing stuff between worktrees
  refs.c: indent with tabs, not spaces
2018-11-13 22:37:26 +09:00
Rafael Ascensão
9ab9b5df0e refs: fix some exclude patterns being ignored
`--exclude` from rev-list and rev-parse fails to exclude references if
the next `--branches`, `--tags` or `--remotes` use the optional
inclusive glob because those options are implemented as particular cases
of `--glob=`, which itself requires that exclude patterns begin with
'refs/'.

But it makes sense for `--branches=glob` and friends to be aware that
exclusions patterns for them shouldn't be 'refs/<type>/' prefixed, the
same way exclude patterns for `--branches` and friends (without the
optional glob) already are.

Let's record in 'refs.c:struct ref_filter' which context the exclude
pattern is tied to, so refs.c:filter_refs() can decide if it should
ignore the prefix when trying to match.

Signed-off-by: Rafael Ascensão <rafa.almas@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-13 14:41:22 +09:00
Nguyễn Thái Ngọc Duy
3a3b9d8cde refs: new ref types to make per-worktree refs visible to all worktrees
One of the problems with multiple worktree is accessing per-worktree
refs of one worktree from another worktree. This was sort of solved by
multiple ref store, where the code can open the ref store of another
worktree and has access to the ref space of that worktree.

The problem with this is reporting. "HEAD" in another ref space is
also called "HEAD" like in the current ref space. In order to
differentiate them, all the code must somehow carry the ref store
around and print something like "HEAD from this ref store".

But that is not feasible (or possible with a _lot_ of work). With the
current design, we pass a reference around as a string (so called
"refname"). Extending this design to pass a string _and_ a ref store
is a nightmare, especially when handling extended SHA-1 syntax.

So we do it another way. Instead of entering a separate ref space, we
make refs from other worktrees available in the current ref space. So
"HEAD" is always HEAD of the current worktree, but then we can have
"worktrees/blah/HEAD" to denote HEAD from a worktree named
"blah". This syntax coincidentally matches the underlying directory
structure which makes implementation a bit easier.

The main worktree has to be treated specially because well... it's
special from the beginning. So HEAD from the main worktree is
acccessible via the name "main-worktree/HEAD" instead of
"worktrees/main/HEAD" because "main" could be just another secondary
worktree.

This patch also makes it possible to specify refs from one worktree in
another one, e.g.

    git log worktrees/foo/HEAD

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-22 13:32:29 +09:00
Junio C Hamano
6d8f8ebb74 Merge branch 'ds/commit-graph-with-grafts'
The recently introduced commit-graph auxiliary data is incompatible
with mechanisms such as replace & grafts that "breaks" immutable
nature of the object reference relationship.  Disable optimizations
based on its use (and updating existing commit-graph) when these
incompatible features are in use in the repository.

* ds/commit-graph-with-grafts:
  commit-graph: close_commit_graph before shallow walk
  commit-graph: not compatible with uninitialized repo
  commit-graph: not compatible with grafts
  commit-graph: not compatible with replace objects
  test-repository: properly init repo
  commit-graph: update design document
  refs.c: upgrade for_each_replace_ref to be a each_repo_ref_fn callback
  refs.c: migrate internal ref iteration to pass thru repository argument
2018-10-16 16:15:59 +09:00
Nguyễn Thái Ngọc Duy
8aff1a9ca5 Add a place for (not) sharing stuff between worktrees
When multiple worktrees are used, we need rules to determine if
something belongs to one worktree or all of them. Instead of keeping
adding rules when new stuff comes (*), have a generic rule:

- Inside $GIT_DIR, which is per-worktree by default, add
  $GIT_DIR/common which is always shared. New features that want to
  share stuff should put stuff under this directory.

- Inside refs/, which is shared by default except refs/bisect, add
  refs/worktree/ which is per-worktree. We may eventually move
  refs/bisect to this new location and remove the exception in refs
  code.

(*) And it may also include stuff from external commands which will
    have no way to modify common/per-worktree rules.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-07 08:21:18 +09:00
Nguyễn Thái Ngọc Duy
5c79f74f05 refs.c: indent with tabs, not spaces
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-07 08:21:18 +09:00
Jeff King
9001dc2a74 convert "oidcmp() != 0" to "!oideq()"
This is the flip side of the previous two patches: checking
for a non-zero oidcmp() can be more strictly expressed as
inequality. Like those patches, we write "!= 0" in the
coccinelle transformation, which covers by isomorphism the
more common:

  if (oidcmp(E1, E2))

As with the previous two patches, this patch can be achieved
almost entirely by running "make coccicheck"; the only
differences are manual line-wrap fixes to match the original
code.

There is one thing to note for anybody replicating this,
though: coccinelle 1.0.4 seems to miss the case in
builtin/tag.c, even though it's basically the same as all
the others. Running with 1.0.7 does catch this, so
presumably it's just a coccinelle bug that was fixed in the
interim.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-29 11:32:49 -07:00
Stefan Beller
212e0f7efe refs.c: upgrade for_each_replace_ref to be a each_repo_ref_fn callback
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-21 10:22:50 -07:00
Stefan Beller
4a6067cda5 refs.c: migrate internal ref iteration to pass thru repository argument
In 60ce76d358 (refs: add repository argument to for_each_replace_ref,
2018-04-11) and 0d296c57ae (refs: allow for_each_replace_ref to handle
arbitrary repositories, 2018-04-11), for_each_replace_ref learned how
to iterate over refs by a given arbitrary repository.
New attempts in the object store conversion have shown that it is useful
to have the repository handle available that the refs iteration is
currently iterating over.

To achieve this goal we will need to add a repository argument to
each_ref_fn in refs.h. However as many callers rely on the signature
such a patch would be too large.

So convert the internals of the ref subsystem first to pass through a
repository argument without exposing the change to the user. Assume
the_repository for the passed through repository, although it is not
used anywhere yet.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-21 10:22:50 -07:00
Junio C Hamano
72c11b7e62 Merge branch 'jt/refspec-dwim-precedence-fix'
"git fetch $there refs/heads/s" ought to fetch the tip of the
branch 's', but when "refs/heads/refs/heads/s", i.e. a branch whose
name is "refs/heads/s" exists at the same time, fetched that one
instead by mistake.  This has been corrected to honor the usual
disambiguation rules for abbreviated refnames.

* jt/refspec-dwim-precedence-fix:
  remote: make refspec follow the same disambiguation rule as local refs
2018-08-17 13:09:55 -07:00
Junio C Hamano
4bea8485e3 Merge branch 'nd/i18n'
Many more strings are prepared for l10n.

* nd/i18n: (23 commits)
  transport-helper.c: mark more strings for translation
  transport.c: mark more strings for translation
  sha1-file.c: mark more strings for translation
  sequencer.c: mark more strings for translation
  replace-object.c: mark more strings for translation
  refspec.c: mark more strings for translation
  refs.c: mark more strings for translation
  pkt-line.c: mark more strings for translation
  object.c: mark more strings for translation
  exec-cmd.c: mark more strings for translation
  environment.c: mark more strings for translation
  dir.c: mark more strings for translation
  convert.c: mark more strings for translation
  connect.c: mark more strings for translation
  config.c: mark more strings for translation
  commit-graph.c: mark more strings for translation
  builtin/replace.c: mark more strings for translation
  builtin/pack-objects.c: mark more strings for translation
  builtin/grep.c: mark strings for translation
  builtin/config.c: mark more strings for translation
  ...
2018-08-15 15:08:23 -07:00
Junio C Hamano
3a2a1dc170 Merge branch 'sb/object-store-lookup'
lookup_commit_reference() and friends have been updated to find
in-core object for a specific in-core repository instance.

* sb/object-store-lookup: (32 commits)
  commit.c: allow lookup_commit_reference to handle arbitrary repositories
  commit.c: allow lookup_commit_reference_gently to handle arbitrary repositories
  tag.c: allow deref_tag to handle arbitrary repositories
  object.c: allow parse_object to handle arbitrary repositories
  object.c: allow parse_object_buffer to handle arbitrary repositories
  commit.c: allow get_cached_commit_buffer to handle arbitrary repositories
  commit.c: allow set_commit_buffer to handle arbitrary repositories
  commit.c: migrate the commit buffer to the parsed object store
  commit-slabs: remove realloc counter outside of slab struct
  commit.c: allow parse_commit_buffer to handle arbitrary repositories
  tag: allow parse_tag_buffer to handle arbitrary repositories
  tag: allow lookup_tag to handle arbitrary repositories
  commit: allow lookup_commit to handle arbitrary repositories
  tree: allow lookup_tree to handle arbitrary repositories
  blob: allow lookup_blob to handle arbitrary repositories
  object: allow lookup_object to handle arbitrary repositories
  object: allow object_as_type to handle arbitrary repositories
  tag: add repository argument to deref_tag
  tag: add repository argument to parse_tag_buffer
  tag: add repository argument to lookup_tag
  ...
2018-08-02 15:30:42 -07:00
Junio C Hamano
60650a48c0 remote: make refspec follow the same disambiguation rule as local refs
When matching a non-wildcard LHS of a refspec against a list of
refs, find_ref_by_name_abbrev() returns the first ref that matches
using any DWIM rules used by refname_match() in refs.c, even if a
better match occurs later in the list of refs.

This causes unexpected behavior when (for example) fetching using
the refspec "refs/heads/s:<something>" from a remote with both
"refs/heads/refs/heads/s" and "refs/heads/s"; even if the former was
inadvertently created, one would still expect the latter to be
fetched.  Similarly, when both a tag T and a branch T exist,
fetching T should favor the tag, just like how local refname
disambiguation rule works.  But because the code walks over
ls-remote output from the remote, which happens to be sorted in
alphabetical order and has refs/heads/T before refs/tags/T, a
request to fetch T is (mis)interpreted as fetching refs/heads/T.

Update refname_match(), all of whose current callers care only if it
returns non-zero (i.e. matches) to see if an abbreviated name can
mean the full name being tested, so that it returns a positive
integer whose magnitude can be used to tell the precedence, and fix
the find_ref_by_name_abbrev() function not to stop at the first
match but find the match with the highest precedence.

This is based on an earlier work, which special cased only the exact
matches, by Jonathan Tan.

Helped-by: Jonathan Tan <jonathantanmy@google.com>
Helped-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-02 12:16:52 -07:00
Junio C Hamano
9cb10ca9df Merge branch 'bp/log-ref-write-fd-with-strbuf'
Code clean-up.

* bp/log-ref-write-fd-with-strbuf:
  convert log_ref_write_fd() to use strbuf
2018-07-24 14:50:47 -07:00
Nguyễn Thái Ngọc Duy
661558f0a5 refs.c: mark more strings for translation
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-07-23 11:19:10 -07:00
Nguyễn Thái Ngọc Duy
1a07e59c3e Update messages in preparation for i18n
Many messages will be marked for translation in the following
commits. This commit updates some of them to be more consistent and
reduce diff noise in those commits. Changes are

- keep the first letter of die(), error() and warning() in lowercase
- no full stop in die(), error() or warning() if it's single sentence
  messages
- indentation
- some messages are turned to BUG(), or prefixed with "BUG:" and will
  not be marked for i18n
- some messages are improved to give more information
- some messages are broken down by sentence to be i18n friendly
  (on the same token, combine multiple warning() into one big string)
- the trailing \n is converted to printf_ln if possible, or deleted
  if not redundant
- errno_errno() is used instead of explicit strerror()

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-07-23 11:19:09 -07:00
Junio C Hamano
00624d608c Merge branch 'sb/object-store-grafts'
The conversion to pass "the_repository" and then "a_repository"
throughout the object access API continues.

* sb/object-store-grafts:
  commit: allow lookup_commit_graft to handle arbitrary repositories
  commit: allow prepare_commit_graft to handle arbitrary repositories
  shallow: migrate shallow information into the object parser
  path.c: migrate global git_path_* to take a repository argument
  cache: convert get_graft_file to handle arbitrary repositories
  commit: convert read_graft_file to handle arbitrary repositories
  commit: convert register_commit_graft to handle arbitrary repositories
  commit: convert commit_graft_pos() to handle arbitrary repositories
  shallow: add repository argument to is_repository_shallow
  shallow: add repository argument to check_shallow_file_for_update
  shallow: add repository argument to register_shallow
  shallow: add repository argument to set_alternate_shallow_file
  commit: add repository argument to lookup_commit_graft
  commit: add repository argument to prepare_commit_graft
  commit: add repository argument to read_graft_file
  commit: add repository argument to register_commit_graft
  commit: add repository argument to commit_graft_pos
  object: move grafts to object parser
  object-store: move object access functions to object-store.h
2018-07-18 12:20:28 -07:00
Ben Peart
80a6c2073b convert log_ref_write_fd() to use strbuf
Since we don't care about how many bytes were written, simplify the return
value logic.

log_ref_write_fd() was written long before strbuf was fleshed out. Remove
the old manual buffer management code and replace it with strbuf(). Also
update copy_reflog_msg() which is called only by log_ref_write_fd() to use
strbuf as it keeps things consistent.

Signed-off-by: Ben Peart <Ben.Peart@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-07-10 14:22:44 -07:00
Stefan Beller
1268dfac1e object: add repository argument to object_as_type
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-29 10:43:38 -07:00
Junio C Hamano
b16b60f71b Merge branch 'sb/object-store-grafts' into sb/object-store-lookup
* sb/object-store-grafts:
  commit: allow lookup_commit_graft to handle arbitrary repositories
  commit: allow prepare_commit_graft to handle arbitrary repositories
  shallow: migrate shallow information into the object parser
  path.c: migrate global git_path_* to take a repository argument
  cache: convert get_graft_file to handle arbitrary repositories
  commit: convert read_graft_file to handle arbitrary repositories
  commit: convert register_commit_graft to handle arbitrary repositories
  commit: convert commit_graft_pos() to handle arbitrary repositories
  shallow: add repository argument to is_repository_shallow
  shallow: add repository argument to check_shallow_file_for_update
  shallow: add repository argument to register_shallow
  shallow: add repository argument to set_alternate_shallow_file
  commit: add repository argument to lookup_commit_graft
  commit: add repository argument to prepare_commit_graft
  commit: add repository argument to read_graft_file
  commit: add repository argument to register_commit_graft
  commit: add repository argument to commit_graft_pos
  object: move grafts to object parser
  object-store: move object access functions to object-store.h
2018-06-29 10:43:28 -07:00
Junio C Hamano
7c3d15fe31 Merge branch 'jk/snprintf-truncation'
Avoid unchecked snprintf() to make future code auditing easier.

* jk/snprintf-truncation:
  fmt_with_err: add a comment that truncation is OK
  shorten_unambiguous_ref: use xsnprintf
  fsmonitor: use internal argv_array of struct child_process
  log_write_email_headers: use strbufs
  http: use strbufs instead of fixed buffers
2018-05-30 21:51:28 +09:00
Junio C Hamano
26597cb0cc Merge branch 'ma/create-pseudoref-with-null-old-oid'
"git update-ref A B" is supposed to ensure that ref A does not yet
exist when B is a NULL OID, but this check was not done correctly
for pseudo-refs outside refs/ hierarchy, e.g. MERGE_HEAD.

* ma/create-pseudoref-with-null-old-oid:
  refs: handle zero oid for pseudorefs
  t1400: add tests around adding/deleting pseudorefs
  refs.c: refer to "object ID", not "sha1", in error messages
2018-05-30 14:04:08 +09:00
Junio C Hamano
50f08db594 Merge branch 'js/use-bug-macro'
Developer support update, by using BUG() macro instead of die() to
mark codepaths that should not happen more clearly.

* js/use-bug-macro:
  BUG_exit_code: fix sparse "symbol not declared" warning
  Convert remaining die*(BUG) messages
  Replace all die("BUG: ...") calls by BUG() ones
  run-command: use BUG() to report bugs, not die()
  test-tool: help verifying BUG() code paths
2018-05-30 14:04:07 +09:00
Junio C Hamano
2f76ebc93c Merge branch 'ma/lockfile-cleanup'
Code clean-up to adjust to a more recent lockfile API convention that
allows lockfile instances kept on the stack.

* ma/lockfile-cleanup:
  lock_file: move static locks into functions
  lock_file: make function-local locks non-static
  refs.c: do not die if locking fails in `delete_pseudoref()`
  refs.c: do not die if locking fails in `write_pseudoref()`
  t/helper/test-write-cache: clean up lock-handling
2018-05-30 14:04:05 +09:00
Junio C Hamano
2c18e6ae24 Merge branch 'js/rebase-recreate-merge'
"git rebase" learned "--rebase-merges" to transplant the whole
topology of commit graph elsewhere.

* js/rebase-recreate-merge:
  rebase -i --rebase-merges: add a section to the man page
  rebase -i: introduce --rebase-merges=[no-]rebase-cousins
  pull: accept --rebase=merges to recreate the branch topology
  rebase --rebase-merges: avoid "empty merges"
  sequencer: handle post-rewrite for merge commands
  sequencer: make refs generated by the `label` command worktree-local
  rebase --rebase-merges: add test for --keep-empty
  rebase: introduce the --rebase-merges option
  rebase-helper --make-script: introduce a flag to rebase merges
  sequencer: fast-forward `merge` commands, if possible
  sequencer: introduce the `merge` command
  sequencer: introduce new commands to reset the revision
  git-rebase--interactive: clarify arguments
  sequencer: offer helpful advice when a command was rescheduled
  sequencer: refactor how original todo list lines are accessed
  sequencer: make rearrange_squash() a bit more obvious
  sequencer: avoid using errno clobbered by rollback_lock_file()
2018-05-23 14:38:20 +09:00
Junio C Hamano
fcb6df3254 Merge branch 'sb/oid-object-info'
The codepath around object-info API has been taught to take the
repository object (which in turn tells the API which object store
the objects are to be located).

* sb/oid-object-info:
  cache.h: allow oid_object_info to handle arbitrary repositories
  packfile: add repository argument to cache_or_unpack_entry
  packfile: add repository argument to unpack_entry
  packfile: add repository argument to read_object
  packfile: add repository argument to packed_object_info
  packfile: add repository argument to packed_to_object_type
  packfile: add repository argument to retry_bad_packed_offset
  cache.h: add repository argument to oid_object_info
  cache.h: add repository argument to oid_object_info_extended
2018-05-23 14:38:16 +09:00
Junio C Hamano
a2cec42213 Merge branch 'sb/object-store-replace'
Hotfix.

* sb/object-store-replace:
  get_main_ref_store: BUG() when outside a repository
  object.c: clear replace map before freeing it
  replace-object.c: remove the_repository from prepare_replace_object
  object.c: free replace map in raw_object_store_clear
2018-05-23 14:38:09 +09:00
Jeff King
bf4baf1fed shorten_unambiguous_ref: use xsnprintf
We convert the ref_rev_parse_rules array into scanf formats
on the fly, and use snprintf() to write into each string. We
should have enough memory to hold everything because of the
earlier total_len computation. Let's use xsnprintf() to
give runtime confirmation that this is the case, and to make
it easy for people auditing the code to know there's no
truncation bug.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-21 09:59:03 +09:00
Jeff King
2dc417ab1f get_main_ref_store: BUG() when outside a repository
If we don't have a repository, then we can't initialize the
ref store.  Prior to 64a741619d (refs: store the main ref
store inside the repository struct, 2018-04-11), we'd try to
access get_git_dir(), and outside a repository that would
trigger a BUG(). After that commit, though, we directly use
the_repository->git_dir; if it's NULL we'll just segfault.

Let's catch this case and restore the BUG() behavior.
Obviously we don't ever want to hit this code, but a BUG()
is a lot more helpful than a segfault if we do.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-21 09:45:23 +09:00
Stefan Beller
cbd53a2193 object-store: move object access functions to object-store.h
This should make these functions easier to find and cache.h less
overwhelming to read.

In particular, this moves:
- read_object_file
- oid_object_info
- write_object_file

As a result, most of the codebase needs to #include object-store.h.
In this patch the #include is only added to files that would fail to
compile otherwise.  It would be better to #include wherever
identifiers from the header are used.  That can happen later
when we have better tooling for it.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-16 11:42:03 +09:00
Martin Ågren
db0210d445 refs: handle zero oid for pseudorefs
According to the documentation, it is possible to "specify 40 '0' or an
empty string as <oldvalue> to make sure that the ref you are creating
does not exist." But in the code for pseudorefs, we do not implement
this, as demonstrated by the failing tests added in the previous commit.
If we fail to read the old ref, we immediately die. But a failure to
read would actually be a good thing if we have been given the zero oid.

With the zero oid, allow -- and even require -- the ref-reading to fail.
This implements the "make sure that the ref ... does not exist" part of
the documentation and fixes both failing tests from the previous commit.

Since we have a `strbuf err` for collecting errors, let's use it and
signal an error to the caller instead of dying hard.

Reported-by: Rafael Ascensão <rafa.almas@gmail.com>
Helped-by: Rafael Ascensão <rafa.almas@gmail.com>
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-13 10:36:11 +09:00
Martin Ågren
c0bdd658bd refs.c: refer to "object ID", not "sha1", in error messages
We have two error messages that complain about the "sha1". Because we
are about to touch one of these sites and add some tests, let's first
modernize the messages to say "object ID" instead.

While at it, make the second one use `error()` instead of `warning()`.
After printing the message, we do not continue, but actually drop the
lock and return -1 without deleting the pseudoref.

Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-13 10:36:11 +09:00
Martin Ågren
3c6fad4a3f refs.c: do not die if locking fails in delete_pseudoref()
After taking the lock we check whether we got it and die otherwise. But
since we take the lock using `LOCK_DIE_ON_ERROR`, we would already have
died.

Considering the choice between dropping the dead code and dropping the
flag, let's go for option number three: Drop the flag, write an error
instead of dying, then return -1. This function already returns -1 for
another error, so the caller (or rather, its callers) should be able to
handle this. There is some inconsistency around how we handle errors in
this function and elsewhere in this file, but let's take this small step
towards gentle error-reporting now and leave the rest for another time.

While at it, make the lock non-static and reduce its scope. (Placing
`struct lock_file`s on the stack used to be a bad idea, because the
temp- and lockfile-machinery would keep a pointer into the struct. But
after 076aa2cbd (tempfile: auto-allocate tempfiles on heap, 2017-09-05),
we can safely have lockfiles on the stack.)

Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-10 14:54:45 +09:00
Martin Ågren
010845157a refs.c: do not die if locking fails in write_pseudoref()
If we could not take the lock, we add an error to the `strbuf err` and
return. However, this code is dead. The reason is that we take the lock
using `LOCK_DIE_ON_ERROR`. Drop the flag to allow our more gentle
error-handling to actually kick in.

We could instead just drop the dead code and die here. But everything is
prepared for gently propagating the error, so let's do that instead.

There is similar dead code in `delete_pseudoref()`, but let's save that
for the next patch.

While at it, make the lock non-static. (Placing `struct lock_file`s on
the stack used to be a bad idea, because the temp- and
lockfile-machinery would keep a pointer into the struct. But after
076aa2cbd (tempfile: auto-allocate tempfiles on heap, 2017-09-05), we
can safely have lockfiles on the stack.)

Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-10 14:54:45 +09:00
Junio C Hamano
174774cd51 Merge branch 'sb/object-store-replace'
The effort to pass the repository in-core structure throughout the
API continues.  This round deals with the code that implements the
refs/replace/ mechanism.

* sb/object-store-replace:
  replace-object: allow lookup_replace_object to handle arbitrary repositories
  replace-object: allow do_lookup_replace_object to handle arbitrary repositories
  replace-object: allow prepare_replace_object to handle arbitrary repositories
  refs: allow for_each_replace_ref to handle arbitrary repositories
  refs: store the main ref store inside the repository struct
  replace-object: add repository argument to lookup_replace_object
  replace-object: add repository argument to do_lookup_replace_object
  replace-object: add repository argument to prepare_replace_object
  refs: add repository argument to for_each_replace_ref
  refs: add repository argument to get_main_ref_store
  replace-object: check_replace_refs is safe in multi repo environment
  replace-object: eliminate replace objects prepared flag
  object-store: move lookup_replace_object to replace-object.h
  replace-object: move replace_map to object store
  replace_object: use oidmap
2018-05-08 15:59:21 +09:00
Junio C Hamano
9bfa0f9be3 Merge branch 'bw/protocol-v2'
The beginning of the next-gen transfer protocol.

* bw/protocol-v2: (35 commits)
  remote-curl: don't request v2 when pushing
  remote-curl: implement stateless-connect command
  http: eliminate "# service" line when using protocol v2
  http: don't always add Git-Protocol header
  http: allow providing extra headers for http requests
  remote-curl: store the protocol version the server responded with
  remote-curl: create copy of the service name
  pkt-line: add packet_buf_write_len function
  transport-helper: introduce stateless-connect
  transport-helper: refactor process_connect_service
  transport-helper: remove name parameter
  connect: don't request v2 when pushing
  connect: refactor git_connect to only get the protocol version once
  fetch-pack: support shallow requests
  fetch-pack: perform a fetch using v2
  upload-pack: introduce fetch server command
  push: pass ref prefixes when pushing
  fetch: pass ref prefixes when fetching
  ls-remote: pass ref prefixes when requesting a remote's refs
  transport: convert transport_get_remote_refs to take a list of ref prefixes
  ...
2018-05-08 15:59:16 +09:00
Johannes Schindelin
033abf97fc Replace all die("BUG: ...") calls by BUG() ones
In d8193743e0 (usage.c: add BUG() function, 2017-05-12), a new macro
was introduced to use for reporting bugs instead of die(). It was then
subsequently used to convert one single caller in 588a538ae5
(setup_git_env: convert die("BUG") to BUG(), 2017-05-12).

The cover letter of the patch series containing this patch
(cf 20170513032414.mfrwabt4hovujde2@sigill.intra.peff.net) is not
terribly clear why only one call site was converted, or what the plan
is for other, similar calls to die() to report bugs.

Let's just convert all remaining ones in one fell swoop.

This trick was performed by this invocation:

	sed -i 's/die("BUG: /BUG("/g' $(git grep -l 'die("BUG' \*.c)

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-06 19:06:13 +09:00