Commit Graph

224 Commits

Author SHA1 Message Date
Junio C Hamano
c7ac8c0a7c Merge branch 'jk/index-pack-hotfixes'
Hotfix and clean-up for the jt/threaded-index-pack topic that has
graduated to v2.29-rc0.

* jk/index-pack-hotfixes:
  index-pack: make get_base_data() comment clearer
  index-pack: drop type_cas mutex
  index-pack: restore "resolving deltas" progress meter
2020-10-08 21:53:26 -07:00
Jonathan Tan
ec6a8f9705 index-pack: make get_base_data() comment clearer
A comment mentions that we may free cached delta bases via
find_unresolved_deltas(), but that function went away in f08cbf60fe
(index-pack: make quantum of work smaller, 2020-09-08). Since we need to
rewrite that comment anyway, make the entire comment clearer.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-10-07 13:32:27 -07:00
Jeff King
bebe171947 index-pack: drop type_cas mutex
The type_cas lock lost all of its callers in f08cbf60fe (index-pack:
make quantum of work smaller, 2020-09-08), so we can safely delete it.
The compiler didn't alert us that the variable became unused, because we
still call pthread_mutex_init() and pthread_mutex_destroy() on it.

It's worth considering also whether that commit was in error to remove
the use of the lock. Why don't we need it now, if we did before, as
described in ab791dd138 (index-pack: fix race condition with duplicate
bases, 2014-08-29)? I think the answer is that we now look at and assign
the child_obj->real_type field in the main thread while holding the
work_lock(). So we don't have to worry about racing with the worker
threads.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-10-07 11:51:26 -07:00
Jeff King
cea69151a4 index-pack: restore "resolving deltas" progress meter
Commit f08cbf60fe (index-pack: make quantum of work smaller, 2020-09-08)
refactored the main loop in threaded_second_pass(), but also deleted the
call to display_progress() at the top of the loop. This means that users
typically see no progress at all during the delta resolution phase (and
for large repositories, Git appears to hang).

This looks like an accident that was unrelated to the intended change of
that commit, since we continue to update nr_resolved_deltas in
resolve_delta(). Let's restore the call to get that progress back.

We'll also add a test that confirms we generate the expected progress.
This isn't perfect, as it wouldn't catch a bug where progress was
delayed to the end. That was probably possible to trigger when receiving
a thin pack, because we'd eventually call display_progress() from
fix_unresolved_deltas(), but only once after doing all the work.
However, since our test case generates a complete pack, it reliably
demonstrates this particular bug and its fix. And we can't do better
without making the test racy.

Signed-off-by: Jeff King <peff@peff.net>
Acked-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-10-07 11:50:09 -07:00
Junio C Hamano
b7e65b51e5 Merge branch 'jt/threaded-index-pack'
"git index-pack" learned to resolve deltified objects with greater
parallelism.

* jt/threaded-index-pack:
  index-pack: make quantum of work smaller
  index-pack: make resolve_delta() assume base data
  index-pack: calculate {ref,ofs}_{first,last} early
  index-pack: remove redundant child field
  index-pack: unify threaded and unthreaded code
  index-pack: remove redundant parameter
  Documentation: deltaBaseCacheLimit is per-thread
2020-09-22 12:36:28 -07:00
Jonathan Tan
f08cbf60fe index-pack: make quantum of work smaller
Currently, when index-pack resolves deltas, it does not split up delta
trees into threads: each delta base root (an object that is not a
REF_DELTA or OFS_DELTA) can go into its own thread, but all deltas on
that root (direct or indirect) are processed in the same thread.

This is a problem when a repository contains a large text file (thus,
delta-able) that is modified many times - delta resolution time during
fetching is dominated by processing the deltas corresponding to that
text file.

This patch contains a solution to that. When cloning using

  git -c core.deltabasecachelimit=1g clone \
    https://fuchsia.googlesource.com/third_party/vulkan-cts

on my laptop, clone time improved from 3m2s to 2m5s (using 3 threads,
which is the default).

The solution is to have a global work stack. This stack contains delta
bases (objects, whether appearing directly in the packfile or generated
by delta resolution, that themselves have delta children) that need to
be processed; whenever a thread needs work, it peeks at the top of the
stack and processes its next unprocessed child. If a thread finds the
stack empty, it will look for more delta base roots to push on the stack
instead.

The main weakness of having a global work stack is that more time is
spent in the mutex, but profiling has shown that most time is spent in
the resolution of the deltas themselves, so this shouldn't be an issue
in practice. In any case, experimentation (as described in the clone
command above) shows that this patch is a net improvement.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-08 15:52:17 -07:00
Jonathan Tan
ee6f058384 index-pack: make resolve_delta() assume base data
A subsequent commit will make the quantum of work smaller, necessitating
more locking. This commit allows resolve_delta() to be called outside
the lock.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-24 14:14:52 -07:00
Jonathan Tan
b4718cae51 index-pack: calculate {ref,ofs}_{first,last} early
This is refactoring 2 of 2 to simplify struct base_data.

Whenever we make a struct base_data, immediately calculate its delta
children. This eliminates confusion as to when the
{ref,ofs}_{first,last} fields are initialized.

Before this patch, the delta children were calculated at the last
possible moment. This allowed the members of struct base_data to be
populated in any order, superficially useful when we have the object
contents before the struct object_entry. But this makes reasoning about
the state of struct base_data more complicated, hence this patch.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-24 14:12:58 -07:00
Jonathan Tan
a7f7e84a49 index-pack: remove redundant child field
This is refactoring 1 of 2 to simplify struct base_data.

In index-pack, each thread maintains a doubly-linked list of the delta
chain that it is currently processing (the "base" and "child" pointers
in struct base_data). When a thread exceeds the delta base cache limit
and needs to reclaim memory, it uses the "child" pointers to traverse
the lineage, reclaiming the memory of the eldest delta bases first.

A subsequent patch will perform memory reclaiming in a different way and
will thus no longer need the "child" pointer. Because the "child"
pointer is redundant even now, remove it so that the aforementioned
subsequent patch will be clearer. In the meantime, reclaim memory in the
reverse order of the "base" pointers.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-24 14:11:14 -07:00
Jonathan Tan
46e6fb1e44 index-pack: unify threaded and unthreaded code
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-24 14:02:31 -07:00
Jonathan Tan
fc968e26c2 index-pack: remove redundant parameter
find_{ref,ofs}_delta_{,children} take an enum object_type parameter, but
the object type is already present in the name of the function. Remove
that parameter from these functions.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-24 13:55:57 -07:00
Jeff King
fbff95b67f index-pack: adjust default threading cap
Commit b8a2486f15 (index-pack: support multithreaded delta resolving,
2012-05-06) describes an experiment that shows that setting the number
of threads for index-pack higher than 3 does not help.

I repeated that experiment using a more modern version of Git and a more
modern CPU and got different results.

Here are timings for p5302 against linux.git run on my laptop, a Core
i9-9880H with 8 cores plus hyperthreading (so online-cpus returns 16):

  5302.3: index-pack 0 threads                   256.28(253.41+2.79)
  5302.4: index-pack 1 threads                   257.03(254.03+2.91)
  5302.5: index-pack 2 threads                   149.39(268.34+3.06)
  5302.6: index-pack 4 threads                   94.96(294.10+3.23)
  5302.7: index-pack 8 threads                   68.12(339.26+3.89)
  5302.8: index-pack 16 threads                  70.90(655.03+7.21)
  5302.9: index-pack default number of threads   116.91(290.05+3.21)

You can see that wall-clock times continue to improve dramatically up to
the number of cores, but bumping beyond that (into hyperthreading
territory) does not help (and in fact hurts a little).

Here's the same experiment on a machine with dual Xeon 6230's, totaling
40 cores (80 with hyperthreading):

  5302.3: index-pack 0 threads                    310.04(302.73+6.90)
  5302.4: index-pack 1 threads                    310.55(302.68+7.40)
  5302.5: index-pack 2 threads                    178.17(304.89+8.20)
  5302.6: index-pack 5 threads                    99.53(315.54+9.56)
  5302.7: index-pack 10 threads                   72.80(327.37+12.79)
  5302.8: index-pack 20 threads                   60.68(357.74+21.66)
  5302.9: index-pack 40 threads                   58.07(454.44+67.96)
  5302.10: index-pack 80 threads                  59.81(720.45+334.52)
  5302.11: index-pack default number of threads   134.18(309.32+7.98)

The results are similar; things stop improving at 40 threads. Curiously,
going from 20 to 40 really doesn't help much, either (and increases CPU
time considerably). So that may represent an actual barrier to
parallelism, where we lose out due to context-switching and loss of
cache locality, but don't reap the wall-clock benefits due to contention
of our coarse-grained locks.

So what's a good default value? It's clear that the current cap of 3 is
too low; our default values are 42% and 57% slower than the best times
on each machine. The results on the 40-core machine imply that 20
threads is an actual barrier regardless of the number of cores, so we'll
take that as a maximum. We get the best results on these machines at
half of the online-cpus value. That's presumably a result of the
hyperthreading. That's common on multi-core Intel processors, but not
necessarily elsewhere. But if we take it as an assumption, we can
perform optimally on hyperthreaded machines and still do much better
than the status quo on other machines, as long as we never half below
the current value of 3.

So that's what this patch does.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-21 12:02:36 -07:00
brian m. carlson
586740aa6e builtin/index-pack: add option to specify hash algorithm
git index-pack is usually run in a repository, but need not be. Since
packs don't contains information on the algorithm in use, instead
relying on context, add an option to index-pack to tell it which one
we're using in case someone runs it outside of a repository.  Since
using --stdin necessarily implies a repository, don't allow specifying
an object format if it's provided to prevent users from passing an
option that won't work.  Add documentation for this option.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-06-19 14:04:08 -07:00
brian m. carlson
629dffc461 packfile: compute and use the index CRC offset
Both v2 pack index files and the v3 format specified as part of the
NewHash work have similar data starting at the CRC table.  Much of the
existing code wants to read either this table or the offset entries
following it, and in doing so computes the offset each time.

In order to share as much code between v2 and v3, compute the offset of
the CRC table and store it when the pack is opened.  Use this value to
compute offsets to not only the CRC table, but to the offset entries
beyond it.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-05-27 10:07:07 -07:00
Jonathan Tan
db7ed7418b promisor-remote: accept 0 as oid_nr in function
There are 3 callers to promisor_remote_get_direct() that first check if
the number of objects to be fetched is equal to 0. Fold that check into
promisor_remote_get_direct(), and in doing so, be explicit as to what
promisor_remote_get_direct() does if oid_nr is 0 (it returns 0, success,
immediately).

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-02 12:42:32 -07:00
Junio C Hamano
7b029ebaef Merge branch 'jk/index-pack-dupfix'
The index-pack code now diagnoses a bad input packstream that
records the same object twice when it is used as delta base; the
code used to declare a software bug when encountering such an
input, but it is an input error.

* jk/index-pack-dupfix:
  index-pack: downgrade twice-resolved REF_DELTA to die()
2020-02-14 12:54:24 -08:00
Jeff King
a21781011f index-pack: downgrade twice-resolved REF_DELTA to die()
When we're resolving a REF_DELTA, we compare-and-swap its type from
REF_DELTA to whatever real type the base object has, as discussed in
ab791dd138 (index-pack: fix race condition with duplicate bases,
2014-08-29). If the old type wasn't a REF_DELTA, we consider that a
BUG(). But as discussed in that commit, we might see this case whenever
we try to resolve an object twice, which may happen because we have
multiple copies of the base object.

So this isn't a bug at all, but rather a sign that the input pack is
broken. And indeed, this case is triggered already in t5309.5 and
t5309.6, which create packs with delta cycles and duplicate bases. But
we never noticed because those tests are marked expect_failure.

Those tests were added by b2ef3d9ebb (test index-pack on packs with
recoverable delta cycles, 2013-08-23), which was leaving the door open
for cases that we theoretically _could_ handle. And when we see an
already-resolved object like this, in theory we could keep going after
confirming that the previously resolved child->real_type matches
base->obj->real_type. But:

  - enforcing the "only resolve once" rule here saves us from an
    infinite loop in other parts of the code. If we keep going, then the
    delta cycle in t5309.5 causes us to loop infinitely, as
    find_ref_delta_children() doesn't realize which objects have already
    been resolved. So there would be more changes needed to make this
    case work, and in the meantime we'd be worse off.

  - any pack that triggers this is broken anyway. It either has a
    duplicate base object, or it has a cycle which causes us to bring in
    a duplicate via --fix-thin. In either case, we'd end up rejecting
    the pack in write_idx_file(), which also detects duplicates.

So the tests have little value in documenting what we _could_ be doing
(and have been neglected for 6+ years). Let's switch them to confirming
that we handle this case cleanly (and switch out the BUG() for a more
informative die() so that we do so).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-04 13:19:11 -08:00
Matheus Tavares
b98d188581 sha1-file: allow check_object_signature() to handle any repo
Some callers of check_object_signature() can work on arbitrary
repositories, but the repo does not get passed to this function.
Instead, the_repository is always used internally. To fix possible
inconsistencies, allow the function to receive a struct repository and
make those callers pass on the repo being handled.

Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-31 10:45:39 -08:00
Matheus Tavares
2dcde20e1c sha1-file: pass git_hash_algo to hash_object_file()
Allow hash_object_file() to work on arbitrary repos by introducing a
git_hash_algo parameter. Change callers which have a struct repository
pointer in their scope to pass on the git_hash_algo from the said repo.
For all other callers, pass on the_hash_algo, which was already being
used internally at hash_object_file(). This functionality will be used
in the following patch to make check_object_signature() be able to work
on arbitrary repos (which, in turn, will be used to fix an
inconsistency at object.c:parse_object()).

Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-31 10:45:39 -08:00
Matheus Tavares
c8123e72f6 streaming: allow open_istream() to handle any repo
Some callers of open_istream() at archive-tar.c and archive-zip.c are
capable of working on arbitrary repositories but the repo struct is not
passed down to open_istream(), which uses the_repository internally. For
now, that's not a problem since the said callers are only being called
with the_repository. But to be consistent and avoid future problems,
let's allow open_istream() to receive a struct repository and use that
instead of the_repository. This parameter addition will also be used in
a future patch to make sha1-file.c:check_object_signature() be able to
work on arbitrary repos.

Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-31 10:45:39 -08:00
Junio C Hamano
676278f8ea Merge branch 'bc/object-id-part17'
Preparation for SHA-256 upgrade continues.

* bc/object-id-part17: (26 commits)
  midx: switch to using the_hash_algo
  builtin/show-index: replace sha1_to_hex
  rerere: replace sha1_to_hex
  builtin/receive-pack: replace sha1_to_hex
  builtin/index-pack: replace sha1_to_hex
  packfile: replace sha1_to_hex
  wt-status: convert struct wt_status to object_id
  cache: remove null_sha1
  builtin/worktree: switch null_sha1 to null_oid
  builtin/repack: write object IDs of the proper length
  pack-write: use hash_to_hex when writing checksums
  sequencer: convert to use the_hash_algo
  bisect: switch to using the_hash_algo
  sha1-lookup: switch hard-coded constants to the_hash_algo
  config: use the_hash_algo in abbrev comparison
  combine-diff: replace GIT_SHA1_HEXSZ with the_hash_algo
  bundle: switch to use the_hash_algo
  connected: switch GIT_SHA1_HEXSZ to the_hash_algo
  show-index: switch hard-coded constants to the_hash_algo
  blame: remove needless comparison with GIT_SHA1_HEXSZ
  ...
2019-10-11 14:24:46 +09:00
brian m. carlson
69fa337060 builtin/index-pack: replace sha1_to_hex
Since sha1_to_hex is limited to SHA-1, replace it with hash_to_hex so
this code works with other algorithms.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-08-19 15:04:59 -07:00
Christian Couder
b14ed5adaf Use promisor_remote_get_direct() and has_promisor_remote()
Instead of using the repository_format_partial_clone global
and fetch_objects() directly, let's use has_promisor_remote()
and promisor_remote_get_direct().

This way all the configured promisor remotes will be taken
into account, not only the one specified by
extensions.partialClone.

Also when cloning or fetching using a partial clone filter,
remote.origin.promisor will be set to "true" instead of
setting extensions.partialClone to "origin". This makes it
possible to use many promisor remote just by fetching from
them.

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-25 14:05:37 -07:00
Jonathan Tan
8a30a1efd1 index-pack: prefetch missing REF_DELTA bases
When fetching, the client sends "have" commit IDs indicating that the
server does not need to send any object referenced by those commits,
reducing network I/O. When the client is a partial clone, the client
still sends "have"s in this way, even if it does not have every object
referenced by a commit it sent as "have".

If a server omits such an object, it is fine: the client could lazily
fetch that object before this fetch, and it can still do so after.

The issue is when the server sends a thin pack containing an object that
is a REF_DELTA against such a missing object: index-pack fails to fix
the thin pack. When support for lazily fetching missing objects was
added in 8b4c0103a9 ("sha1_file: support lazily fetching missing
objects", 2017-12-08), support in index-pack was turned off in the
belief that it accesses the repo only to do hash collision checks.
However, this is not true: it also needs to access the repo to resolve
REF_DELTA bases.

Support for lazy fetching should still generally be turned off in
index-pack because it is used as part of the lazy fetching process
itself (if not, infinite loops may occur), but we do need to fetch the
REF_DELTA bases. (When fetching REF_DELTA bases, it is unlikely that
those are REF_DELTA themselves, because we do not send "have" when
making such fetches.)

To resolve this, prefetch all missing REF_DELTA bases before attempting
to resolve them. This both ensures that all bases are attempted to be
fetched, and ensures that we make only one request per index-pack
invocation, and not one request per missing object.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-05-15 11:01:40 +09:00
SZEDER Gábor
79e3aa6624 index-pack: show progress while checking objects
When 'git index-pack' is run by 'git clone', its check_objects()
function usually doesn't take long enough to be a concern, but I just
run into a situation where it took about a minute or so: I
inadvertently put some memory pressure on my tiny laptop while cloning
linux.git, and then there was quite a long silence between the
"Resolving deltas" and "Checking connectivity" progress bars.

Show a progress bar during the loop of check_objects() to let the user
know that something is still going on.

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-04-01 18:08:05 +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
f5f0f68d61 Merge branch 'tb/print-size-t-with-uintmax-format'
Code preparation to replace ulong vars with size_t vars where
appropriate.

* tb/print-size-t-with-uintmax-format:
  Upcast size_t variables to uintmax_t when printing
2018-11-19 16:24:41 +09:00
Torsten Bögershausen
ca473cef91 Upcast size_t variables to uintmax_t when printing
When printing variables which contain a size, today "unsigned long"
is used at many places.
In order to be able to change the type from "unsigned long" into size_t
some day in the future, we need to have a way to print 64 bit variables
on a system that has "unsigned long" defined to be 32 bit, like Win64.

Upcast all those variables into uintmax_t before they are printed.
This is to prepare for a bigger change, when "unsigned long"
will be converted into size_t for variables which may be > 4Gib.

Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-12 16:43:52 +09:00
Nguyễn Thái Ngọc Duy
2094c5e582 index-pack: remove #ifdef NO_PTHREADS
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-05 13:42:11 +09:00
Jeff King
67947c34ae convert "hashcmp() != 0" to "!hasheq()"
This rounds out the previous three patches, covering the
inequality logic for the "hash" variant of the functions.

As with the previous three, the accompanying code changes
are the mechanical result of applying the coccinelle patch;
see those patches for more discussion.

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
Jeff King
4a7e27e957 convert "oidcmp() == 0" to oideq()
Using the more restrictive oideq() should, in the long run,
give the compiler more opportunities to optimize these
callsites. For now, this conversion should be a complete
noop with respect to the generated code.

The result is also perhaps a little more readable, as it
avoids the "zero is equal" idiom. Since it's so prevalent in
C, I think seasoned programmers tend not to even notice it
anymore, but it can sometimes make for awkward double
negations (e.g., we can drop a few !!oidcmp() instances
here).

This patch was generated almost entirely by the included
coccinelle patch. This mechanical conversion should be
completely safe, because we check explicitly for cases where
oidcmp() is compared to 0, which is what oideq() is doing
under the hood. Note that we don't have to catch "!oidcmp()"
separately; coccinelle's standard isomorphisms make sure the
two are treated equivalently.

I say "almost" because I did hand-edit the coccinelle output
to fix up a few style violations (it mostly keeps the
original formatting, but sometimes unwraps long lines).

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
Junio C Hamano
1689c22c1c Merge branch 'jk/core-use-replace-refs'
A new configuration variable core.usereplacerefs has been added,
primarily to help server installations that want to ignore the
replace mechanism altogether.

* jk/core-use-replace-refs:
  add core.usereplacerefs config option
  check_replace_refs: rename to read_replace_refs
  check_replace_refs: fix outdated comment
2018-08-15 15:08:23 -07:00
Jeff King
6ebd1cafe2 check_replace_refs: rename to read_replace_refs
This was added as a NEEDSWORK in c3c36d7de2 (replace-object:
check_replace_refs is safe in multi repo environment, 2018-04-11),
waiting for a calmer period. Since doing so now doesn't conflict
with anything in 'pu', it seems as good a time as any.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-07-18 15:45:14 -07:00
Stefan Beller
da14a7ff99 blob: add repository argument to lookup_blob
Add a repository argument to allow the callers of lookup_blob
to be more specific about which repository to act on. This is a small
mechanical change; it doesn't change the implementation to handle
repositories other than the_repository yet.

As with the previous commits, use a macro to catch callers passing a
repository other than the_repository at compile time.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
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
Stefan Beller
1ec5bfd24e object: add repository argument to parse_object_buffer
Add a repository argument to allow the callers of parse_object_buffer
to be more specific about which repository to act on. This is a small
mechanical change; it doesn't change the implementation to handle
repositories other than the_repository yet.

As with the previous commits, use a macro to catch callers passing a
repository other than the_repository at compile time.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
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
549ca8aa7c Merge branch 'jk/index-pack-maint'
"index-pack --strict" has been taught to make sure that it runs the
final object integrity checks after making the freshly indexed
packfile available to itself.

* jk/index-pack-maint:
  index-pack: correct install_packed_git() args
  index-pack: handle --strict checks of non-repo packs
  prepare_commit_graft: treat non-repository as a noop
2018-06-13 12:50:46 -07:00
Junio C Hamano
3737746120 index-pack: correct install_packed_git() args
The function does not start taking the repository object as a
parameter before v2.18 track.  Make the topic mergeable to v2.17
maintenance track by dropping it.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-11 15:09:18 -07:00
Jeff King
368b4e5906 index-pack: handle --strict checks of non-repo packs
Commit 73c3f0f704 (index-pack: check .gitmodules files with
--strict, 2018-05-04) added a call to add_packed_git(), with
the intent that the newly-indexed objects would be available
to the process when we run fsck_finish().  But that's not
what add_packed_git() does. It only allocates the struct,
and you must install_packed_git() on the result. So that
call was effectively doing nothing (except leaking a
struct).

But wait, we passed all of the tests! Does that mean we
don't need the call at all?

For normal cases, no. When we run "index-pack --stdin"
inside a repository, we write the new pack into the object
directory. If fsck_finish() needs to access one of the new
objects, then our initial lookup will fail to find it, but
we'll follow up by running reprepare_packed_git() and
looking again. That logic was meant to handle somebody else
repacking simultaneously, but it ends up working for us
here.

But there is a case that does need this, that we were not
testing. You can run "git index-pack foo.pack" on any file,
even when it is not inside the object directory. Or you may
not even be in a repository at all! This case fails without
doing the proper install_packed_git() call.

We can make this work by adding the install call.

Note that we should be prepared to handle add_packed_git()
failing. We can just silently ignore this case, though. If
fsck_finish() later needs the objects and they're not
available, it will complain itself. And if it doesn't
(because we were able to resolve the whole fsck in the first
pass), then it actually isn't an interesting error at all.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-01 11:48:56 +09:00
Junio C Hamano
42c8ce1c49 Merge branch 'bc/object-id'
Conversion from uchar[20] to struct object_id continues.

* bc/object-id: (42 commits)
  merge-one-file: compute empty blob object ID
  add--interactive: compute the empty tree value
  Update shell scripts to compute empty tree object ID
  sha1_file: only expose empty object constants through git_hash_algo
  dir: use the_hash_algo for empty blob object ID
  sequencer: use the_hash_algo for empty tree object ID
  cache-tree: use is_empty_tree_oid
  sha1_file: convert cached object code to struct object_id
  builtin/reset: convert use of EMPTY_TREE_SHA1_BIN
  builtin/receive-pack: convert one use of EMPTY_TREE_SHA1_HEX
  wt-status: convert two uses of EMPTY_TREE_SHA1_HEX
  submodule: convert several uses of EMPTY_TREE_SHA1_HEX
  sequencer: convert one use of EMPTY_TREE_SHA1_HEX
  merge: convert empty tree constant to the_hash_algo
  builtin/merge: switch tree functions to use object_id
  builtin/am: convert uses of EMPTY_TREE_SHA1_BIN to the_hash_algo
  sha1-file: add functions for hex empty tree and blob OIDs
  builtin/receive-pack: avoid hard-coded constants for push certs
  diff: specify abbreviation size in terms of the_hash_algo
  upload-pack: replace use of several hard-coded constants
  ...
2018-05-30 14:04:10 +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
7913f53b56 Sync with Git 2.17.1
* maint: (25 commits)
  Git 2.17.1
  Git 2.16.4
  Git 2.15.2
  Git 2.14.4
  Git 2.13.7
  fsck: complain when .gitmodules is a symlink
  index-pack: check .gitmodules files with --strict
  unpack-objects: call fsck_finish() after fscking objects
  fsck: call fsck_finish() after fscking objects
  fsck: check .gitmodules content
  fsck: handle promisor objects in .gitmodules check
  fsck: detect gitmodules files
  fsck: actually fsck blob data
  fsck: simplify ".git" check
  index-pack: make fsck error message more specific
  verify_path: disallow symlinks in .gitmodules
  update-index: stat updated files earlier
  verify_dotfile: mention case-insensitivity in comment
  verify_path: drop clever fallthrough
  skip_prefix: add case-insensitive variant
  ...
2018-05-29 17:10:05 +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
Jeff King
73c3f0f704 index-pack: check .gitmodules files with --strict
Now that the internal fsck code has all of the plumbing we
need, we can start checking incoming .gitmodules files.
Naively, it seems like we would just need to add a call to
fsck_finish() after we've processed all of the objects. And
that would be enough to cover the initial test included
here. But there are two extra bits:

  1. We currently don't bother calling fsck_object() at all
     for blobs, since it has traditionally been a noop. We'd
     actually catch these blobs in fsck_finish() at the end,
     but it's more efficient to check them when we already
     have the object loaded in memory.

  2. The second pass done by fsck_finish() needs to access
     the objects, but we're actually indexing the pack in
     this process. In theory we could give the fsck code a
     special callback for accessing the in-pack data, but
     it's actually quite tricky:

       a. We don't have an internal efficient index mapping
	  oids to packfile offsets. We only generate it on
	  the fly as part of writing out the .idx file.

       b. We'd still have to reconstruct deltas, which means
          we'd basically have to replicate all of the
	  reading logic in packfile.c.

     Instead, let's avoid running fsck_finish() until after
     we've written out the .idx file, and then just add it
     to our internal packed_git list.

     This does mean that the objects are "in the repository"
     before we finish our fsck checks. But unpack-objects
     already exhibits this same behavior, and it's an
     acceptable tradeoff here for the same reason: the
     quarantine mechanism means that pushes will be
     fully protected.

In addition to a basic push test in t7415, we add a sneaky
pack that reverses the usual object order in the pack,
requiring that index-pack access the tree and blob during
the "finish" step.

This already works for unpack-objects (since it will have
written out loose objects), but we'll check it with this
sneaky pack for good measure.

Signed-off-by: Jeff King <peff@peff.net>
2018-05-21 23:55:12 -04:00
Jeff King
db5a58c1bd index-pack: make fsck error message more specific
If fsck reports an error, we say only "Error in object".
This isn't quite as bad as it might seem, since the fsck
code would have dumped some errors to stderr already. But it
might help to give a little more context. The earlier output
would not have even mentioned "fsck", and that may be a clue
that the "fsck.*" or "*.fsckObjects" config may be relevant.

Signed-off-by: Jeff King <peff@peff.net>
2018-05-21 23:55:12 -04:00
Junio C Hamano
b10edb2df5 Merge branch 'ds/commit-graph'
Precompute and store information necessary for ancestry traversal
in a separate file to optimize graph walking.

* ds/commit-graph:
  commit-graph: implement "--append" option
  commit-graph: build graph from starting commits
  commit-graph: read only from specific pack-indexes
  commit: integrate commit graph with commit parsing
  commit-graph: close under reachability
  commit-graph: add core.commitGraph setting
  commit-graph: implement git commit-graph read
  commit-graph: implement git-commit-graph write
  commit-graph: implement write_commit_graph()
  commit-graph: create git-commit-graph builtin
  graph: add commit graph design document
  commit-graph: add format document
  csum-file: refactor finalize_hashfile() method
  csum-file: rename hashclose() to finalize_hashfile()
2018-05-08 15:59:20 +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
brian m. carlson
5d9e198245 index-pack: abstract away hash function constant
The code for reading certain pack v2 offsets had a hard-coded 5
representing the number of uint32_t words that we needed to skip over.
Specify this value in terms of a value from the_hash_algo.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-02 13:59:51 +09:00
Stefan Beller
0df8e96566 cache.h: add repository argument to oid_object_info
Add a repository argument to allow the callers of oid_object_info
to be more specific about which repository to handle. This is a small
mechanical change; it doesn't change the implementation to handle
repositories other than the_repository yet.

As with the previous commits, use a macro to catch callers passing a
repository other than the_repository at compile time.

Signed-off-by: Stefan Beller <sbeller@google.com>
Reviewed-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-04-26 10:54:27 +09:00
Stefan Beller
fc1395f4a4 sha1_file.c: rename to use dash in file name
This is more consistent with the project style. The majority of Git's
source files use dashes in preference to underscores in their file names.

Signed-off-by: Stefan Beller <sbeller@google.com>
2018-04-11 18:11:00 +09:00
Stefan Beller
d807c4a01d exec_cmd: rename to use dash in file name
This is more consistent with the project style. The majority of Git's
source files use dashes in preference to underscores in their file names.

Signed-off-by: Stefan Beller <sbeller@google.com>
2018-04-11 18:11:00 +09:00