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2694 Commits

Author SHA1 Message Date
Han-Wen Nienhuys e48d427268 reftable: implement stack, a mutable database of reftable files.
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-08 10:45:48 -07:00
Han-Wen Nienhuys acb533440f reftable: implement refname validation
The packed/loose format has restrictions on refnames: a and a/b cannot
coexist. This limitation does not apply to reftable per se, but must be
maintained for interoperability. This code adds validation routines to
abort transactions that are trying to add invalid names.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-08 10:45:48 -07:00
Han-Wen Nienhuys 1ae2b8cda8 reftable: add merged table view
This adds an abstract, read-only interface to the ref database.

This primitive is used to construct the read view of the ref database
(the read view is constructed by merging several *.ref files). It also
provides the mechanism to provide a unified view of the refs in the main
repository and the per-worktree refs.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-08 10:45:48 -07:00
Han-Wen Nienhuys 3b34f636df reftable: add a heap-based priority queue for reftable records
This is needed to create a merged view multiple reftables

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-08 10:45:48 -07:00
Han-Wen Nienhuys ffc97f1a9e reftable: reftable file level tests
With support for reading and writing files in place, we can construct files (in
memory) and attempt to read them back.

Because some sections of the format are optional (eg. indices, log entries), we
have to exercise this code using multiple sizes of input data

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-08 10:45:48 -07:00
Han-Wen Nienhuys 46bc0e731a reftable: read reftable files
This supports reading a single reftable file.

The commit introduces an abstract iterator type, which captures the usecases
both of reading individual refs, and iterating over a segment of the ref
namespace.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-08 10:45:48 -07:00
Han-Wen Nienhuys 17df8dbeba reftable: generic interface to tables
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-08 10:45:48 -07:00
Han-Wen Nienhuys f14bd71934 reftable: write reftable files
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-08 10:45:48 -07:00
Han-Wen Nienhuys 35425d1034 reftable: a generic binary tree implementation
The reftable format includes support for an (OID => ref) map. This map can speed
up visibility and reachability checks. In particular, various operations along
the fetch/push path within Gerrit have ben sped up by using this structure.

The map is constructed with help of a binary tree. Object IDs are hashes, so
they are uniformly distributed. Hence, the tree does not attempt forced
rebalancing.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-08 10:45:48 -07:00
Han-Wen Nienhuys e581fd7231 reftable: reading/writing blocks
The reftable format is structured as a sequence of block. Within a block,
records are prefix compressed, with an index of offsets for fully expand keys to
enable binary search within blocks.

This commit provides the logic to read and write these blocks.

Helped-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-08 10:45:48 -07:00
Han-Wen Nienhuys a322920d0b Provide zlib's uncompress2 from compat/zlib-compat.c
This will be needed for reading reflog blocks in reftable.

Helped-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-08 10:45:48 -07:00
Han-Wen Nienhuys e303bf22f9 reftable: (de)serialization for the polymorphic record type.
The reftable format is structured as a sequence of blocks, and each block
contains a sequence of prefix-compressed key-value records. There are 4 types of
records, and they have similarities in how they must be handled. This is
achieved by introducing a polymorphic 'record' type that encapsulates ref, log,
index and object records.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-08 10:45:48 -07:00
Han-Wen Nienhuys 1214aa841b reftable: add blocksource, an abstraction for random access reads
The reftable format is usually used with files for storage. However, we abstract
away this using the blocksource data structure. This has two advantages:

* log blocks are zlib compressed, and handling them is simplified if we can
  discard byte segments from within the block layer.

* for unittests, it is useful to read and write in-memory. The blocksource
  allows us to abstract the data away from on-disk files.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-08 10:45:48 -07:00
Han-Wen Nienhuys ef8a6c6268 reftable: utility functions
This commit provides basic utility classes for the reftable library.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-08 10:45:48 -07:00
Junio C Hamano 6f64eeab60 Merge branch 'es/trace2-log-parent-process-name'
trace2 logs learned to show parent process name to see in what
context Git was invoked.

* es/trace2-log-parent-process-name:
  tr2: log parent process name
  tr2: make process info collection platform-generic
2021-08-24 15:32:40 -07:00
Junio C Hamano aab0eeaba5 Merge branch 'js/expand-runtime-prefix'
Pathname expansion (like "~username/") learned a way to specify a
location relative to Git installation (e.g. its $sharedir which is
$(prefix)/share), with "%(prefix)".

* js/expand-runtime-prefix:
  expand_user_path: allow in-flight topics to keep using the old name
  interpolate_path(): allow specifying paths relative to the runtime prefix
  Use a better name for the function interpolating paths
  expand_user_path(): clarify the role of the `real_home` parameter
  expand_user_path(): remove stale part of the comment
  tests: exercise the RUNTIME_PREFIX feature
2021-08-24 15:32:38 -07:00
Junio C Hamano fea3738ac5 Merge branch 'ab/getcwd-test'
Portability test update.

* ab/getcwd-test:
  t0001: fix broken not-quite getcwd(3) test in bed67874e2
2021-08-04 13:28:55 -07:00
Ævar Arnfjörð Bjarmason 482e1488a9 t0001: fix broken not-quite getcwd(3) test in bed67874e2
With a54e938e5b (strbuf: support long paths w/o read rights in
strbuf_getcwd() on FreeBSD, 2017-03-26) we had t0001 break on systems
like OpenBSD and AIX whose getcwd(3) has standard (but not like glibc
et al) behavior.

This was partially fixed in bed67874e2 (t0001: skip test with
restrictive permissions if getpwd(3) respects them, 2017-08-07).

The problem with that fix is that while its analysis of the problem is
correct, it doesn't actually call getcwd(3), instead it invokes "pwd
-P". There is no guarantee that "pwd -P" is going to call getcwd(3),
as opposed to e.g. being a shell built-in.

On AIX under both bash and ksh this test breaks because "pwd -P" will
happily display the current working directory, but getcwd(3) called by
the "git init" we're testing here will fail to get it.

I checked whether clobbering the $PWD environment variable would
affect it, and it didn't. Presumably these shells keep track of their
working directory internally.

There's possible follow-up work here in teaching strbuf_getcwd() to
get the working directory with whatever method "pwd" uses on these
platforms. See [1] for a discussion of that, but let's take the easy
way out here and just skip these tests by fixing the
GETCWD_IGNORES_PERMS prerequisite to match the limitations of
strbuf_getcwd().

1. https://lore.kernel.org/git/b650bef5-d739-d98d-e9f1-fa292b6ce982@web.de/

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-30 10:18:27 -07:00
Junio C Hamano e5cc59c77c Merge branch 'ew/many-alternate-optim'
Optimization for repositories with many alternate object store.

* ew/many-alternate-optim:
  oidtree: a crit-bit tree for odb_loose_cache
  oidcpy_with_padding: constify `src' arg
  make object_directory.loose_objects_subdir_seen a bitmap
  avoid strlen via strbuf_addstr in link_alt_odb_entry
  speed up alt_odb_usable() with many alternates
2021-07-28 13:17:57 -07:00
Johannes Schindelin b7d11a0f5d tests: exercise the RUNTIME_PREFIX feature
Originally, we refrained from adding a regression test in 7b6c649637
(system_path(): Add prefix computation at runtime if RUNTIME_PREFIX set,
2008-08-10), and in 226c0ddd0d (exec_cmd: RUNTIME_PREFIX on some POSIX
systems, 2018-04-10).

The reason was that it was deemed too tricky to test.

Turns out that it is not tricky to test at all: we simply create a
pseudo-root, copy the `git` executable into the `git/` subdirectory of
that pseudo-root, then copy a script into the `libexec/git-core/`
directory and expect that to be picked up.

As long as the trash directory is in a location where binaries can be
executed, this works.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-26 12:17:16 -07:00
Emily Shaffer b7e6a41622 tr2: make process info collection platform-generic
To pave the way for non-Windows platforms to define
trace2_collect_process_info(), reorganize the stub-or-definition schema
to something which doesn't directly reference Windows.

Platforms which want to collect parent process information in the
future should:

 1. Add an implementation to compat/ (e.g. compat/somearch/procinfo.c)
 2. Add that object to COMPAT_OBJS to config.mak.uname
    (e.g. COMPAT_OBJS += compat/somearch/procinfo.o)
 3. Define HAVE_PLATFORM_PROCINFO in config.mak.uname

In the Windows case, this definition lives in
compat/win32/trace2_win32_process_info.c, which is already conditionally
added to COMPAT_OBJS; so let's add HAVE_PLATFORM_PROCINFO to hint to the
build that compat/stub/procinfo.c should not be used.

Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
Helped-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-22 13:35:20 -07:00
Junio C Hamano dae59cb263 Merge branch 'js/ci-windows-update'
GitHub Actions / CI update.

* js/ci-windows-update:
  ci: accelerate the checkout
  ci (vs-build): build with NO_GETTEXT
  artifacts-tar: respect NO_GETTEXT
  ci (windows): transfer also the Git-tracked files to the test jobs
  ci: upgrade to using actions/{up,down}load-artifacts v2
  ci (vs-build): use `cmd` to copy the DLLs, not `powershell`
  ci: use the new GitHub Action to download git-sdk-64-minimal
2021-07-22 13:05:55 -07:00
Junio C Hamano 8721e2eaed Merge branch 'jt/partial-clone-submodule-1'
Prepare the internals for lazily fetching objects in submodules
from their promisor remotes.

* jt/partial-clone-submodule-1:
  promisor-remote: teach lazy-fetch in any repo
  run-command: refactor subprocess env preparation
  submodule: refrain from filtering GIT_CONFIG_COUNT
  promisor-remote: support per-repository config
  repository: move global r_f_p_c to repo struct
2021-07-16 17:42:53 -07:00
Junio C Hamano 368cab75c1 Merge branch 'ab/make-delete-on-error'
Use ".DELETE_ON_ERROR" pseudo target to simplify our Makefile.

* ab/make-delete-on-error:
  Makefile: add and use the ".DELETE_ON_ERROR" flag
2021-07-16 17:42:47 -07:00
Junio C Hamano 0800bedcc7 Merge branch 'dd/svn-test-wo-locale-a'
"git-svn" tests assumed that "locale -a", which is used to pick an
available UTF-8 locale, is available everywhere.  A knob has been
introduced to allow testers to specify a suitable locale to use.

* dd/svn-test-wo-locale-a:
  t: use user-specified utf-8 locale for testing svn
2021-07-08 13:14:58 -07:00
Eric Wong 92d8ed8ac1 oidtree: a crit-bit tree for odb_loose_cache
This saves 8K per `struct object_directory', meaning it saves
around 800MB in my case involving 100K alternates (half or more
of those alternates are unlikely to hold loose objects).

This is implemented in two parts: a generic, allocation-free
`cbtree' and the `oidtree' wrapper on top of it.  The latter
provides allocation using alloc_state as a memory pool to
improve locality and reduce free(3) overhead.

Unlike oid-array, the crit-bit tree does not require sorting.
Performance is bound by the key length, for oidtree that is
fixed at sizeof(struct object_id).  There's no need to have
256 oidtrees to mitigate the O(n log n) overhead like we did
with oid-array.

Being a prefix trie, it is natively suited for expanding short
object IDs via prefix-limited iteration in
`find_short_object_filename'.

On my busy workstation, p4205 performance seems to be roughly
unchanged (+/-8%).  Startup with 100K total alternates with no
loose objects seems around 10-20% faster on a hot cache.
(800MB in memory savings means more memory for the kernel FS
cache).

The generic cbtree implementation does impose some extra
overhead for oidtree in that it uses memcmp(3) on
"struct object_id" so it wastes cycles comparing 12 extra bytes
on SHA-1 repositories.  I've not yet explored reducing this
overhead, but I expect there are many places in our code base
where we'd want to investigate this.

More information on crit-bit trees: https://cr.yp.to/critbit.html

Signed-off-by: Eric Wong <e@80x24.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-07 21:28:04 -07:00
Johannes Schindelin 4348824059 artifacts-tar: respect NO_GETTEXT
We obviously do not want to bundle `.mo` files during `make
artifacts-tar NO_GETTEXT=Yep`, but that was the case.

To fix that, go a step beyond just fixing the symptom, and simply
define the lists of `.po` and `.mo` files as empty if `NO_GETTEXT` is
set.

Helped-by: Matthias Aßhauer <mha1993@live.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-06 12:20:58 -07:00
Ævar Arnfjörð Bjarmason 7b76d6bf22 Makefile: add and use the ".DELETE_ON_ERROR" flag
Use the GNU make ".DELETE_ON_ERROR" flag in our main Makefile, as we
already do in the Documentation/Makefile since db10fc6c09 (doc:
simplify Makefile using .DELETE_ON_ERROR, 2021-05-21).

Now if a command to make X fails X will be removed, the default
behavior of GNU make is to only do so if "make" itself is interrupted
with a signal.

E.g. if we now intentionally break one of the rules with:

    -       mv $@+ $@
    +       mv $@+ $@ && \
    +       false

We'll get output like:

    $ make git
        CC git.o
        LINK git
    make: *** [Makefile:2179: git] Error 1
    make: *** Deleting file 'git'
    $ file git
    git: cannot open `git' (No such file or directory)

Before this change we'd leave the file in place in under this
scenario.

As in db10fc6c09 this allows us to remove patterns of removing
leftover $@ files at the start of rules, since previous failing runs
of the Makefile won't have left those littered around anymore.

I'm not as confident that we should be replacing the "mv $@+ $@"
pattern entirely, since that means that external programs or one of
our other Makefiles might race and get partial content.

I'm not changing $(REMOTE_CURL_ALIASES) since that uses a ln/ln -s/cp
dance, and would require the addition of "-f" flags if the "rm" at the
start was removed. I've also got plans to fix that ln/ln -s/cp pattern
in another series.

For $(LIB_FILE) and $(XDIFF_LIB) we can rely on the "c" (create) being
present in ARFLAGS.

I'm not changing "$(ETAGS_TARGET)", "tags" and "cscope" because
they've got a messy combination of removing "$@+" not "$@" at the
beginning, or "$@*". I'm also addressing those in another series.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-06-29 08:03:45 -07:00
Jonathan Tan ef830cc434 promisor-remote: teach lazy-fetch in any repo
This is one step towards supporting partial clone submodules.

Even after this patch, we will still lack partial clone submodules
support, primarily because a lot of Git code that accesses submodule
objects does so by adding their object stores as alternates, meaning
that any lazy fetches that would occur in the submodule would be done
based on the config of the superproject, not of the submodule. This also
prevents testing of the functionality in this patch by user-facing
commands. So for now, test this mechanism using a test helper.

Besides that, there is some code that uses the wrapper functions
like has_promisor_remote(). Those will need to be checked to see if they
could support the non-wrapper functions instead (and thus support any
repository, not just the_repository).

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-06-28 09:58:01 -07:00
Đoàn Trần Công Danh 482c962de4 t: use user-specified utf-8 locale for testing svn
In some test-cases, UTF-8 locale is required. To find such locale,
we're using the first available UTF-8 locale that returned by
"locale -a".

However, the locale(1) utility is unavailable on some systems,
e.g. Linux with musl libc.

However, without "locale -a", we can't guess provided UTF-8 locale.

Add a Makefile knob GIT_TEST_UTF8_LOCALE and activate it for
linux-musl in our CI system.

Rename t/lib-git-svn.sh:prepare_a_utf8_locale to prepare_utf8_locale,
since we no longer prepare the variable named "a_utf8_locale",
but set up a fallback value for GIT_TEST_UTF8_LOCALE instead.
The fallback will be LC_ALL, LANG environment variable,
or the first UTF-8 locale from output of "locale -a", in that order.

Signed-off-by: Đoàn Trần Công Danh <congdanhqx@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-06-08 16:07:37 +09:00
Junio C Hamano 6aae0e2ad2 Merge branch 'jh/simple-ipc-sans-pthread'
The "simple-ipc" did not compile without pthreads support, but the
build procedure was not properly account for it.

* jh/simple-ipc-sans-pthread:
  simple-ipc: correct ifdefs when NO_PTHREADS is defined
2021-05-22 18:29:01 +09:00
Jeff Hostetler 6aac70a870 simple-ipc: correct ifdefs when NO_PTHREADS is defined
Simple IPC always requires threads (in addition to various
platform-specific IPC support).  Fix the ifdefs in the Makefile
to define SUPPORTS_SIMPLE_IPC when appropriate.

Previously, the Unix version of the code would only verify that
Unix domain sockets were available.

This problem was reported here:
https://lore.kernel.org/git/YKN5lXs4AoK%2FJFTO@coredump.intra.peff.net/T/#m08be8f1942ea8a2c36cfee0e51cdf06489fdeafc

Reported-by: Randall S. Becker <rsbecker@nexbridge.com>
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-05-21 07:55:00 +09:00
Junio C Hamano 2e2ed74be0 Merge branch 'ab/perl-makefile-cleanup'
Build procedure clean-up.

* ab/perl-makefile-cleanup:
  Makefile: make PERL_DEFINES recursively expanded
  perl: use mock i18n functions under NO_GETTEXT=Y
  Makefile: regenerate *.pm on NO_PERL_CPAN_FALLBACKS change
  Makefile: regenerate perl/build/* if GIT-PERL-DEFINES changes
  Makefile: don't re-define PERL_DEFINES
2021-05-20 08:54:58 +09:00
Junio C Hamano eede71149e Merge branch 'ba/object-info'
Over-the-wire protocol learns a new request type to ask for object
sizes given a list of object names.

* ba/object-info:
  object-info: support for retrieving object info
2021-05-14 08:26:08 +09:00
Ævar Arnfjörð Bjarmason 8c55753c68 Makefile: make PERL_DEFINES recursively expanded
Since 07d90eadb5 (Makefile: add Perl runtime prefix support,
2018-04-10) PERL_DEFINES has been a simply-expanded variable, let's
make it recursively expanded instead.

This change doesn't matter for the correctness of the logic. Whether
we used simply-expanded or recursively expanded didn't change what we
wrote out in GIT-PERL-DEFINES, but being consistent with other rules
makes this easier to understand.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-05-13 07:45:39 +09:00
Ævar Arnfjörð Bjarmason 256c2dc42c perl: use mock i18n functions under NO_GETTEXT=Y
Change the logic of the i18n functions I added in 5e9637c629 (i18n:
add infrastructure for translating Git with gettext, 2011-11-18) to
use pass-through functions when NO_GETTEXT is defined.

This speeds up the compilation time of commands that use this library
when NO_GETTEXT=Y is in effect. Loading it and POSIX.pm is around 20ms
on my machine, whereas it takes 2ms to just instantiate perl itself.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-05-06 12:58:33 +09:00
Ævar Arnfjörð Bjarmason 368a50d9ee Makefile: regenerate *.pm on NO_PERL_CPAN_FALLBACKS change
Regenerate the *.pm files in perl/build/* if the
NO_PERL_CPAN_FALLBACKS flag added to the *.pm files in
1aca69c019 (perl Git::LoadCPAN: emit better errors under
NO_PERL_CPAN_FALLBACKS, 2018-03-03) is changed.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-05-06 12:58:32 +09:00
Ævar Arnfjörð Bjarmason 3d49f7220a Makefile: regenerate perl/build/* if GIT-PERL-DEFINES changes
Change the logic to generate perl/build/* to regenerate those files if
GIT-PERL-DEFINES changes. This ensures that e.g. changing localedir
will result in correctly re-generated files.

I don't think that ever worked. The brokenness pre-dates my
20d2a30f8f (Makefile: replace perl/Makefile.PL with simple make
rules, 2017-12-10).

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-05-06 12:58:30 +09:00
Ævar Arnfjörð Bjarmason 4070c9e09f Makefile: don't re-define PERL_DEFINES
Since 07d90eadb5 (Makefile: add Perl runtime prefix support,
2018-04-10) we have been declaring PERL_DEFINES right after assigning
to it, with the effect that the first PERL_DEFINES was ignored.

That bug didn't matter in practice since the first line had all the
same variables as the second, so we'd correctly re-generate
everything. It just made for confusing reading.

Let's remove that first assignment, and while we're at it split these
across lines to make them more maintainable.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-05-06 12:58:27 +09:00
Junio C Hamano a1cac26cc6 Merge branch 'mt/parallel-checkout-part-2'
The checkout machinery has been taught to perform the actual
write-out of the files in parallel when able.

* mt/parallel-checkout-part-2:
  parallel-checkout: add design documentation
  parallel-checkout: support progress displaying
  parallel-checkout: add configuration options
  parallel-checkout: make it truly parallel
  unpack-trees: add basic support for parallel checkout
2021-04-30 13:50:26 +09:00
Junio C Hamano 8e97852919 Merge branch 'ds/sparse-index-protections'
Builds on top of the sparse-index infrastructure to mark operations
that are not ready to mark with the sparse index, causing them to
fall back on fully-populated index that they always have worked with.

* ds/sparse-index-protections: (47 commits)
  name-hash: use expand_to_path()
  sparse-index: expand_to_path()
  name-hash: don't add directories to name_hash
  revision: ensure full index
  resolve-undo: ensure full index
  read-cache: ensure full index
  pathspec: ensure full index
  merge-recursive: ensure full index
  entry: ensure full index
  dir: ensure full index
  update-index: ensure full index
  stash: ensure full index
  rm: ensure full index
  merge-index: ensure full index
  ls-files: ensure full index
  grep: ensure full index
  fsck: ensure full index
  difftool: ensure full index
  commit: ensure full index
  checkout: ensure full index
  ...
2021-04-30 13:50:26 +09:00
Bruno Albuquerque a2ba162cda object-info: support for retrieving object info
Sometimes it is useful to get information of an object without having to
download it completely.

Add the "object-info" capability that lets the client ask for
object-related information with their full hexadecimal object names.

Only sizes are returned for now.

Signed-off-by: Bruno Albuquerque <bga@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-20 17:41:13 -07:00
Junio C Hamano b9fa3ba0ca Merge branch 'sg/bugreport-fixes'
The dependencies for config-list.h and command-list.h were broken
when the former was split out of the latter, which has been
corrected.

* sg/bugreport-fixes:
  Makefile: add missing dependencies of 'config-list.h'
2021-04-20 17:23:37 -07:00
Junio C Hamano ab99efc817 Merge branch 'ab/userdiff-tests'
A bit of code clean-up and a lot of test clean-up around userdiff
area.

* ab/userdiff-tests:
  blame tests: simplify userdiff driver test
  blame tests: don't rely on t/t4018/ directory
  userdiff: remove support for "broken" tests
  userdiff tests: list builtin drivers via test-tool
  userdiff tests: explicitly test "default" pattern
  userdiff: add and use for_each_userdiff_driver()
  userdiff style: normalize pascal regex declaration
  userdiff style: declare patterns with consistent style
  userdiff style: re-order drivers in alphabetical order
2021-04-20 17:23:34 -07:00
Matheus Tavares e9e8adf1a8 parallel-checkout: make it truly parallel
Use multiple worker processes to distribute the queued entries and call
write_pc_item() in parallel for them. The items are distributed
uniformly in contiguous chunks. This minimizes the chances of two
workers writing to the same directory simultaneously, which could affect
performance due to lock contention in the kernel. Work stealing (or any
other format of re-distribution) is not implemented yet.

The protocol between the main process and the workers is quite simple.
They exchange binary messages packed in pkt-line format, and use
PKT-FLUSH to mark the end of input (from both sides). The main process
starts the communication by sending N pkt-lines, each corresponding to
an item that needs to be written. These packets contain all the
necessary information to load, smudge, and write the blob associated
with each item. Then it waits for the worker to send back N pkt-lines
containing the results for each item. The resulting packet must contain:
the identification number of the item that it refers to, the status of
the operation, and the lstat() data gathered after writing the file (iff
the operation was successful).

For now, checkout always uses a hardcoded value of 2 workers, only to
demonstrate that the parallel checkout framework correctly divides and
writes the queued entries. The next patch will add user configurations
and define a more reasonable default, based on tests with the said
settings.

Co-authored-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Co-authored-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-19 11:57:05 -07:00
Matheus Tavares 04155bdad8 unpack-trees: add basic support for parallel checkout
This new interface allows us to enqueue some of the entries being
checked out to later uncompress them, apply in-process filters, and
write out the files in parallel. For now, the parallel checkout
machinery is enabled by default and there is no user configuration, but
run_parallel_checkout() just writes the queued entries in sequence
(without spawning additional workers). The next patch will actually
implement the parallelism and, later, we will make it configurable.

Note that, to avoid potential data races, not all entries are eligible
for parallel checkout. Also, paths that collide on disk (e.g.
case-sensitive paths in case-insensitive file systems), are detected by
the parallel checkout code and skipped, so that they can be safely
sequentially handled later. The collision detection works like the
following:

- If the collision was at basename (e.g. 'a/b' and 'a/B'), the framework
  detects it by looking for EEXIST and EISDIR errors after an
  open(O_CREAT | O_EXCL) failure.

- If the collision was at dirname (e.g. 'a/b' and 'A'), it is detected
  at the has_dirs_only_path() check, which is done for the leading path
  of each item in the parallel checkout queue.

Both verifications rely on the fact that, before enqueueing an entry for
parallel checkout, checkout_entry() makes sure that there is no file at
the entry's path and that its leading components are all real
directories. So, any later change in these conditions indicates that
there was a collision (either between two parallel-eligible entries or
between an eligible and an ineligible one).

After all parallel-eligible entries have been processed, the collided
(and thus, skipped) entries are sequentially fed to checkout_entry()
again. This is similar to the way the current code deals with
collisions, overwriting the previously checked out entries with the
subsequent ones. The only difference is that, since we no longer create
the files in the same order that they appear on index, we are not able
to determine which of the colliding entries will survive on disk (for
the classic code, it is always the last entry).

Co-authored-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Co-authored-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-19 11:57:05 -07:00
Junio C Hamano 0623669fc6 Merge branch 'tb/pack-preferred-tips-to-give-bitmap'
A configuration variable has been added to force tips of certain
refs to be given a reachability bitmap.

* tb/pack-preferred-tips-to-give-bitmap:
  builtin/pack-objects.c: respect 'pack.preferBitmapTips'
  t/helper/test-bitmap.c: initial commit
  pack-bitmap: add 'test_bitmap_commits()' helper
2021-04-13 15:28:50 -07:00
SZEDER Gábor 56550ea718 Makefile: add missing dependencies of 'config-list.h'
We auto-generate the list of supported configuration variables from
'Documentation/config/*.txt', and that list used to be created by the
'generate-cmdlist.sh' helper script and stored in the 'command-list.h'
header.  Commit 709df95b78 (help: move list_config_help to
builtin/help, 2020-04-16) extracted this into a dedicated
'generate-configlist.sh' script and 'config-list.h' header, and added
a new target in the 'Makefile' as well, but while doing so it forgot
to extract the dependencies of the latter.  Consequently, since then
'config-list.h' is not re-generated when 'Documentation/config/*.txt'
is updated, while 'command-list.h' is re-generated unnecessarily:

  $ touch Documentation/config/log.txt
  $ make -j4
      GEN command-list.h
      CC help.o
      AR libgit.a

Fix this and list all config-related documentation files as
dependencies of 'config-list.h' and remove them from the dependencies
of 'command-list.h'.

  $ touch Documentation/config/log.txt
  $ make
      GEN config-list.h
      CC builtin/help.o
      LINK git

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-08 15:04:58 -07:00
Junio C Hamano 14cc08de23 Merge branch 'ab/make-tags-quiet'
Generate [ec]tags under $(QUIET_GEN).

* ab/make-tags-quiet:
  Makefile: add QUIET_GEN to "tags" and "TAGS" targets
2021-04-08 13:23:26 -07:00
Ævar Arnfjörð Bjarmason 28e8f0d5e5 userdiff tests: list builtin drivers via test-tool
Change the userdiff test to list the builtin drivers via the
test-tool, using the new for_each_userdiff_driver() API function.

This gets rid of the need to modify this part of the test every time a
new pattern is added, see 2ff6c34612 (userdiff: support Bash,
2020-10-22) and 09dad9256a (userdiff: support Markdown, 2020-05-02)
for two recent examples.

I only need the "list-builtin-drivers "argument here, but let's add
"list-custom-drivers" and "list-drivers" too, just because it's easy.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-08 12:19:10 -07:00