Commit Graph

45 Commits

Author SHA1 Message Date
Abhradeep Chakraborty
ab3892e48f partial-clone: add a partial-clone test case
In a blobless-cloned repo, `git log --follow -- <path>` (`<path>` have
an exact OID rename) shouldn't download blob of the file from where the
new file is renamed.

Add a test case to verify it.

Signed-off-by: Abhradeep Chakraborty <chakrabortyabhradeep79@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-16 11:11:07 -07:00
Eric Sunshine
db5875aa9f t0000-t3999: detect and signal failure within loop
Failures within `for` and `while` loops can go unnoticed if not detected
and signaled manually since the loop itself does not abort when a
contained command fails, nor will a failure necessarily be detected when
the loop finishes since the loop returns the exit code of the last
command it ran on the final iteration, which may not be the command
which failed. Therefore, detect and signal failures manually within
loops using the idiom `|| return 1` (or `|| exit 1` within subshells).

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-13 10:29:48 -08:00
Glen Choo
f30e4d854b fsck: verify commit graph when implicitly enabled
Change fsck to check the "core_commit_graph" variable set in
"repo-settings.c" instead of reading the "core.commitGraph" variable.
This fixes a bug where we wouldn't verify the commit-graph if the
config key was missing. This bug was introduced in
31b1de6a09 (commit-graph: turn on commit-graph by default, 2019-08-13),
where core.commitGraph was turned on by default.

Add tests to "t5318-commit-graph.sh" to verify that fsck checks the
commit-graph as expected for the 3 values of core.commitGraph. Also,
disable GIT_TEST_COMMIT_GRAPH in t/t0410-partial-clone.sh because some
test cases use fsck in ways that assume that commit-graph checking is
disabled.

Helped-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Glen Choo <chooglen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-15 14:30:07 -07:00
Jeff King
d3f17e1723 t0410: disable GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP
Generating a MIDX bitmap causes tests which repack in a partial clone to
fail because they are missing objects. Missing objects is an expected
component of tests in t0410, so disable this knob altogether. Graceful
degradation when writing a bitmap with missing objects is tested in
t5326.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-01 13:56:43 -07:00
Taylor Blau
3ba3d0621b pack-bitmap-write.c: gracefully fail to write non-closed bitmaps
The set of objects covered by a bitmap must be closed under
reachability, since it must be the case that there is a valid bit
position assigned for every possible reachable object (otherwise the
bitmaps would be incomplete).

Pack bitmaps are never written from 'git repack' unless repacking
all-into-one, and so we never write non-closed bitmaps (except in the
case of partial clones where we aren't guaranteed to have all objects).

But multi-pack bitmaps change this, since it isn't known whether the
set of objects in the MIDX is closed under reachability until walking
them. Plumb through a bit that is set when a reachable object isn't
found.

As soon as a reachable object isn't found in the set of objects to
include in the bitmap, bitmap_writer_build() knows that the set is not
closed, and so it now fails gracefully.

A test is added in t0410 to trigger a bitmap write without full
reachability closure by removing local copies of some reachable objects
from a promisor remote.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-08-24 13:21:13 -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
Jonathan Tan
db3c293ecd fetch: no FETCH_HEAD display if --no-write-fetch-head
887952b8c6 ("fetch: optionally allow disabling FETCH_HEAD update",
2020-08-18) introduced the ability to disable writing to FETCH_HEAD
during fetch, but did not suppress the "<source> -> FETCH_HEAD" message
when this ability is used. This message is misleading in this case,
because FETCH_HEAD is not written. Also, because "fetch" is used to
lazy-fetch missing objects in a partial clone, this significantly
clutters up the output in that case since the objects to be fetched are
potentially numerous.

Therefore, suppress this message when --no-write-fetch-head is passed
(but not when --dry-run is set).

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-02 14:26:55 -07:00
Jonathan Tan
7ca3c0ac37 promisor-remote: lazy-fetch objects in subprocess
Teach Git to lazy-fetch missing objects in a subprocess instead of doing
it in-process. This allows any fatal errors that occur during the fetch
to be isolated and converted into an error return value, instead of
causing the current command being run to terminate.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-18 16:46:53 -07:00
brian m. carlson
6c2adf80e9 t0410: mark test with SHA1 prerequisite
These tests try to check that we behave properly if we encounter a
repository with version 0 but an extension.  This is a laudable goal,
but the test cannot work with SHA-256, since SHA-256 repositories always
have an existing extension and are never version 0.

Add a SHA1 prerequisite to these tests.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Reviewed-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-30 09:16:48 -07:00
Jonathan Nieder
62f2eca606 repository: allow repository format upgrade with extensions
Now that we officially permit repository extensions in repository
format v0, permit upgrading a repository with extensions from v0 to v1
as well.

For example, this means a repository where the user has set
"extensions.preciousObjects" can use "git fetch --filter=blob:none
origin" to upgrade the repository to use v1 and the partial clone
extension.

To avoid mistakes, continue to forbid repository format upgrades in v0
repositories with an unrecognized extension.  This way, a v0 user
using a misspelled extension field gets a chance to correct the
mistake before updating to the less forgiving v1 format.

While we're here, make the error message for failure to upgrade the
repository format a bit shorter, and present it as an error, not a
warning.

Reported-by: Huan Huan Chen <huanhuanchen@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-16 09:36:39 -07:00
Jonathan Nieder
11664196ac Revert "check_repository_format_gently(): refuse extensions for old repositories"
This reverts commit 14c7fa269e.

The core.repositoryFormatVersion field was introduced in ab9cb76f66
(Repository format version check., 2005-11-25), providing a welcome
bit of forward compatibility, thanks to some welcome analysis by
Martin Atukunda.  The semantics are simple: a repository with
core.repositoryFormatVersion set to 0 should be comprehensible by all
Git implementations in active use; and Git implementations should
error out early instead of trying to act on Git repositories with
higher core.repositoryFormatVersion values representing new formats
that they do not understand.

A new repository format did not need to be defined until 00a09d57eb
(introduce "extensions" form of core.repositoryformatversion,
2015-06-23).  This provided a finer-grained extension mechanism for
Git repositories.  In a repository with core.repositoryFormatVersion
set to 1, Git implementations can act on "extensions.*" settings that
modify how a repository is interpreted.  In repository format version
1, unrecognized extensions settings cause Git to error out.

What happens if a user sets an extension setting but forgets to
increase the repository format version to 1?  The extension settings
were still recognized in that case; worse, unrecognized extensions
settings do *not* cause Git to error out.  So combining repository
format version 0 with extensions settings produces in some sense the
worst of both worlds.

To improve that situation, since 14c7fa269e
(check_repository_format_gently(): refuse extensions for old
repositories, 2020-06-05) Git instead ignores extensions in v0 mode.
This way, v0 repositories get the historical (pre-2015) behavior and
maintain compatibility with Git implementations that do not know about
the v1 format.  Unfortunately, users had been using this sort of
configuration and this behavior change came to many as a surprise:

- users of "git config --worktree" that had followed its advice
  to enable extensions.worktreeConfig (without also increasing the
  repository format version) would find their worktree configuration
  no longer taking effect

- tools such as copybara[*] that had set extensions.partialClone in
  existing repositories (without also increasing the repository format
  version) would find that setting no longer taking effect

The behavior introduced in 14c7fa269e might be a good behavior if we
were traveling back in time to 2015, but we're far too late.  For some
reason I thought that it was what had been originally implemented and
that it had regressed.  Apologies for not doing my research when
14c7fa269e was under development.

Let's return to the behavior we've had since 2015: always act on
extensions.* settings, regardless of repository format version.  While
we're here, include some tests to describe the effect on the "upgrade
repository version" code path.

[*] ca76c0b1e1

Reported-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-16 09:36:37 -07:00
Xin Li
14c7fa269e check_repository_format_gently(): refuse extensions for old repositories
Previously, extensions were recognized regardless of repository format
version.  If the user sets an undefined "extensions" value on a
repository of version 0 and that value is used by a future git version,
they might get an undesired result.

Because all extensions now also upgrade repository versions, tightening
the check would help avoid this for future extensions.

Signed-off-by: Xin Li <delphij@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-06-05 10:13:30 -07:00
Xin Li
01bbbbd9da fetch: allow adding a filter after initial clone
Retroactively adding a filter can be useful for existing shallow clones as
they allow users to see earlier change histories without downloading all
git objects in a regular --unshallow fetch.

Without this patch, users can make a clone partial by editing the
repository configuration to convert the remote into a promisor, like:

  git config core.repositoryFormatVersion 1
  git config extensions.partialClone origin
  git fetch --unshallow --filter=blob:none origin

Since the hard part of making this work is already in place and such
edits can be error-prone, teach Git to perform the required configuration
change automatically instead.

Note that this change does not modify the existing git behavior which
recognizes setting extensions.partialClone without changing
repositoryFormatVersion.

Signed-off-by: Xin Li <delphij@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-06-05 10:13:30 -07:00
Junio C Hamano
59b19bcd9f Merge branch 'cc/multi-promisor'
Cleanup.

* cc/multi-promisor:
  promisor-remote: skip move_to_tail when no-op
  promisor-remote.h: drop extern from function declaration
2019-10-07 11:33:02 +09:00
Junio C Hamano
ae203ba414 Merge branch 'jt/cache-tree-avoid-lazy-fetch-during-merge'
The cache-tree code has been taught to be less aggressive in
attempting to see if a tree object it computed already exists in
the repository.

* jt/cache-tree-avoid-lazy-fetch-during-merge:
  cache-tree: do not lazy-fetch tentative tree
2019-10-07 11:32:58 +09:00
Emily Shaffer
65904b8b2b promisor-remote: skip move_to_tail when no-op
Previously, when promisor_remote_move_to_tail() is called for a
promisor_remote which is currently the final element in promisors, a
cycle is created in the promisors linked list. This cycle leads to a
double free later on in promisor_remote_clear() when the final element
of the promisors list is removed: promisors is set to promisors->next (a
no-op, as promisors->next == promisors); the previous value of promisors
is free()'d; then the new value of promisors (which is equal to the
previous value of promisors) is also free()'d. This double-free error
was unrecoverable for the user without removing the filter or re-cloning
the repo and hoping to miss this edge case.

Now, when promisor_remote_move_to_tail() would be a no-op, just do a
no-op. In cases of promisor_remote_move_to_tail() where r is not already
at the tail of the list, it works as before.

Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
Acked-by: Christian Couder <christian.couder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-02 14:56:54 +09:00
Junio C Hamano
b9ac6c59b8 Merge branch 'cc/multi-promisor'
Teach the lazy clone machinery that there can be more than one
promisor remote and consult them in order when downloading missing
objects on demand.

* cc/multi-promisor:
  Move core_partial_clone_filter_default to promisor-remote.c
  Move repository_format_partial_clone to promisor-remote.c
  Remove fetch-object.{c,h} in favor of promisor-remote.{c,h}
  remote: add promisor and partial clone config to the doc
  partial-clone: add multiple remotes in the doc
  t0410: test fetching from many promisor remotes
  builtin/fetch: remove unique promisor remote limitation
  promisor-remote: parse remote.*.partialclonefilter
  Use promisor_remote_get_direct() and has_promisor_remote()
  promisor-remote: use repository_format_partial_clone
  promisor-remote: add promisor_remote_reinit()
  promisor-remote: implement promisor_remote_get_direct()
  Add initial support for many promisor remotes
  fetch-object: make functions return an error code
  t0410: remove pipes after git commands
2019-09-18 11:50:09 -07:00
Jonathan Tan
f981ec18cf cache-tree: do not lazy-fetch tentative tree
The cache-tree datastructure is used to speed up the comparison
between the HEAD and the index, and when the index is updated by
a cherry-pick (for example), a tree object that would represent
the paths in the index in a directory is constructed in-core, to
see if such a tree object exists already in the object store.

When the lazy-fetch mechanism was introduced, we converted this
"does the tree exist?" check into an "if it does not, and if we
lazily cloned, see if the remote has it" call by mistake.  Since
the whole point of this check is to repair the cache-tree by
recording an already existing tree object opportunistically, we
shouldn't even try to fetch one from the remote.

Pass the OBJECT_INFO_SKIP_FETCH_OBJECT flag to make sure we only
check for existence in the local object store without triggering the
lazy fetch mechanism.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
[jc: rewritten the proposed log message]
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-09-09 14:07:35 -07:00
Junio C Hamano
f4f8dfe127 Merge branch 'ds/feature-macros'
A mechanism to affect the default setting for a (related) group of
configuration variables is introduced.

* ds/feature-macros:
  repo-settings: create feature.experimental setting
  repo-settings: create feature.manyFiles setting
  repo-settings: parse core.untrackedCache
  commit-graph: turn on commit-graph by default
  t6501: use 'git gc' in quiet mode
  repo-settings: consolidate some config settings
2019-09-09 12:26:36 -07:00
Derrick Stolee
31b1de6a09 commit-graph: turn on commit-graph by default
The commit-graph feature has seen a lot of activity in the past
year or so since it was introduced. The feature is a critical
performance enhancement for medium- to large-sized repos, and
does not significantly hurt small repos.

Change the defaults for core.commitGraph and gc.writeCommitGraph
to true so users benefit from this feature by default.

There are several places in the test suite where the environment
variable GIT_TEST_COMMIT_GRAPH is disabled to avoid reading a
commit-graph, if it exists. The config option overrides the
environment, so swap these. Some GIT_TEST_COMMIT_GRAPH assignments
remain, and those are to avoid writing a commit-graph when a new
commit is created.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-08-13 13:33:55 -07:00
SZEDER Gábor
decfe05bb6 t: warn against adding non-httpd-specific tests after sourcing 'lib-httpd'
We have a couple of test scripts that are not completely
httpd-specific, but do run a few httpd-specific tests at the end.
These test scripts source 'lib-httpd.sh' somewhere mid-script, which
then skips all the rest of the test script if the dependencies for
running httpd tests are not fulfilled.

As the previous two patches in this series show, already on two
occasions non-httpd-specific tests were appended at the end of such
test scripts, and, consequently, they were skipped as well when httpd
tests couldn't be run.

Add a comment at the end of these test scripts to warn against adding
non-httpd-specific tests at the end, in the hope that they will help
prevent similar issues in the future.

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-08-02 09:35:57 -07:00
Christian Couder
9a4c507886 t0410: test fetching from many promisor remotes
This shows that it is now possible to fetch objects from more
than one promisor remote, and that fetching from a new
promisor remote can configure it as one.

Helped-by: SZEDER Gábor <szeder.dev@gmail.com>
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
Christian Couder
fa3d1b63e8 promisor-remote: parse remote.*.partialclonefilter
This makes it possible to specify a different partial clone
filter for each promisor remote.

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
Christian Couder
c59c7c879e t0410: remove pipes after git commands
Let's not run a git command, especially one with "verify" in its
name, upstream of a pipe, because the pipe will hide the git
command's exit code.

While at it, let's also avoid a useless `cat` command piping
into `sed`.

Helped-by: SZEDER Gábor <szeder.dev@gmail.com>
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
SZEDER Gábor
8c3b9f7faa tests: use 'test_atexit' to stop httpd
Use 'test_atexit' to run cleanup commands to stop httpd at the end of
the test script or upon interrupt or failure, as it is shorter,
simpler, and more robust than registering such cleanup commands in the
trap on EXIT in the test scripts.

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-03-14 12:34:39 +09:00
Junio C Hamano
3fe47ff444 Merge branch 'sg/stress-test'
Flaky tests can now be repeatedly run under load with the
"--stress" option.

* sg/stress-test:
  test-lib: add the '--stress' option to run a test repeatedly under load
  test-lib-functions: introduce the 'test_set_port' helper function
  test-lib: set $TRASH_DIRECTORY earlier
  test-lib: consolidate naming of test-results paths
  test-lib: parse command line options earlier
  test-lib: parse options in a for loop to keep $@ intact
  test-lib: extract Bash version check for '-x' tracing
  test-lib: translate SIGTERM and SIGHUP to an exit
2019-01-18 13:49:56 -08:00
Junio C Hamano
c333fe7368 Merge branch 'md/list-lazy-objects-fix'
"git rev-list --exclude-promisor-objects" had to take an object
that does not exist locally (and is lazily available) from the
command line without barfing, but the code dereferenced NULL.

* md/list-lazy-objects-fix:
  list-objects.c: don't segfault for missing cmdline objects
2019-01-14 15:29:28 -08:00
SZEDER Gábor
fa84058180 test-lib-functions: introduce the 'test_set_port' helper function
Several test scripts run daemons like 'git-daemon' or Apache, and
communicate with them through TCP sockets.  To have unique ports where
these daemons are accessible, the ports are usually the number of the
corresponding test scripts, unless the user overrides them via
environment variables, and thus all those tests and test libs contain
more or less the same bit of one-liner boilerplate code to find out
the port.  The last patch in this series will make this a bit more
complicated.

Factor out finding the port for a daemon into the common helper
function 'test_set_port' to avoid repeating ourselves.

Take special care of test scripts with "low" numbers:

  - Test numbers below 1024 would result in a port that's only usable
    as root, so set their port to '10000 + test-nr' to make sure it
    doesn't interfere with other tests in the test suite.  This makes
    the hardcoded port number in 't0410-partial-clone.sh' unnecessary,
    remove it.

  - The shell's arithmetic evaluation interprets numbers with leading
    zeros as octal values, which means that test number below 1000 and
    containing the digits 8 or 9 will trigger an error.  Remove all
    leading zeros from the test numbers to prevent this.

Note that the 'git p4' tests are unlike the other tests involving
daemons in that:

  - 'lib-git-p4.sh' doesn't use the test's number for unique port as
    is, but does a bit of additional arithmetic on top [1].

  - The port is not overridable via an environment variable.

With this patch even 'git p4' tests will use the test's number as
default port, and it will be overridable via the P4DPORT environment
variable.

[1] Commit fc00233071 (git-p4 tests: refactor and cleanup, 2011-08-22)
    introduced that "unusual" unique port computation without
    explaining why it was necessary (as opposed to simply using the
    test number as is).  It seems to be just unnecessary complication,
    and in any case that commit came way before the "test nr as unique
    port" got "standardized" for other daemons in commits c44132fcf3
    (tests: auto-set git-daemon port, 2014-02-10), 3bb486e439 (tests:
    auto-set LIB_HTTPD_PORT from test name, 2014-02-10), and
    bf9d7df950 (t/lib-git-svn.sh: improve svnserve tests with parallel
    make test, 2017-12-01).

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-07 09:24:06 -08:00
Matthew DeVore
4cf67869b2 list-objects.c: don't segfault for missing cmdline objects
When a command is invoked with both --exclude-promisor-objects,
--objects-edge-aggressive, and a missing object on the command line,
the rev_info.cmdline array could get a NULL pointer for the value of
an 'item' field. Prevent dereferencing of a NULL pointer in that
situation.

Properly handle --ignore-missing. If it is not passed, die when an
object is missing. Otherwise, just silently ignore it.

Signed-off-by: Matthew DeVore <matvore@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-12-06 10:10:13 +09:00
Junio C Hamano
77d503757d Merge branch 'md/filter-trees'
The "rev-list --filter" feature learned to exclude all trees via
"tree:0" filter.

* md/filter-trees:
  list-objects: support for skipping tree traversal
  filter-trees: code clean-up of tests
  list-objects-filter: implement filter tree:0
  list-objects-filter-options: do not over-strbuf_init
  list-objects-filter: use BUG rather than die
  revision: mark non-user-given objects instead
  rev-list: handle missing tree objects properly
  list-objects: always parse trees gently
  list-objects: refactor to process_tree_contents
  list-objects: store common func args in struct
2018-10-30 15:43:39 +09:00
Junio C Hamano
fa54cccf1f Merge branch 'jt/non-blob-lazy-fetch'
A partial clone that is configured to lazily fetch missing objects
will on-demand issue a "git fetch" request to the originating
repository to fill not-yet-obtained objects.  The request has been
optimized for requesting a tree object (and not the leaf blob
objects contained in it) by telling the originating repository that
no blobs are needed.

* jt/non-blob-lazy-fetch:
  fetch-pack: exclude blobs when lazy-fetching trees
  fetch-pack: avoid object flags if no_dependents
2018-10-19 13:34:07 +09:00
Matthew DeVore
7c0fe330d5 rev-list: handle missing tree objects properly
Previously, we assumed only blob objects could be missing. This patch
makes rev-list handle missing trees like missing blobs. The --missing=*
and --exclude-promisor-objects flags now work for trees as they already
do for blobs. This is demonstrated in t6112.

Signed-off-by: Matthew DeVore <matvore@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-07 08:55:00 +09:00
Jonathan Tan
4c7f9567ea fetch-pack: exclude blobs when lazy-fetching trees
A partial clone with missing trees can be obtained using "git clone
--filter=tree:none <repo>". In such a repository, when a tree needs to
be lazily fetched, any tree or blob it directly or indirectly references
is fetched as well, regardless of whether the original command required
those objects, or if the local repository already had some of them.

This is because the fetch protocol, which the lazy fetch uses, does not
allow clients to request that only the wanted objects be sent, which
would be the ideal solution. This patch implements a partial solution:
specify the "blob:none" filter, somewhat reducing the fetch payload.

This change has no effect when lazily fetching blobs (due to how filters
work). And if lazily fetching a commit (such repositories are difficult
to construct and is not a use case we support very well, but it is
possible), referenced commits and trees are still fetched - only the
blobs are not fetched.

The necessary code change is done in fetch_pack() instead of somewhere
closer to where the "filter" instruction is written to the wire so that
only one part of the code needs to be changed in order for users of all
protocol versions to benefit from this optimization.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-04 06:03:49 -07:00
Junio C Hamano
ee99ba7afb Merge branch 'jt/lazy-object-fetch-fix'
The code to backfill objects in lazily cloned repository did not
work correctly, which has been corrected.

* jt/lazy-object-fetch-fix:
  fetch-object: set exact_oid when fetching
  fetch-object: unify fetch_object[s] functions
2018-09-24 10:30:52 -07:00
Jonathan Tan
e68302011c fetch-object: set exact_oid when fetching
fetch_objects() currently does not set exact_oid in struct ref when
invoking transport_fetch_refs(). If the server supports ref-in-want,
fetch_pack() uses this field to determine whether a wanted ref should be
requested as a "want-ref" line or a "want" line; without the setting of
exact_oid, the wrong line will be sent.

Set exact_oid, so that the correct line is sent.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-09-13 13:57:31 -07:00
Derrick Stolee
859fdc0c3c commit-graph: define GIT_TEST_COMMIT_GRAPH
The commit-graph feature is tested in isolation by
t5318-commit-graph.sh and t6600-test-reach.sh, but there are many
more interesting scenarios involving commit walks. Many of these
scenarios are covered by the existing test suite, but we need to
maintain coverage when the optional commit-graph structure is not
present.

To allow running the full test suite with the commit-graph present,
add a new test environment variable, GIT_TEST_COMMIT_GRAPH. Similar
to GIT_TEST_SPLIT_INDEX, this variable makes every Git command try
to load the commit-graph when parsing commits, and writes the
commit-graph file after every 'git commit' command.

There are a few tests that rely on commits not existing in
pack-files to trigger important events, so manually set
GIT_TEST_COMMIT_GRAPH to false for the necessary commands.

There is one test in t6024-recursive-merge.sh that relies on the
merge-base algorithm picking one of two ambiguous merge-bases, and
the commit-graph feature changes which merge-base is picked.

Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-29 10:44:31 -07:00
Jonathan Tan
5d19e8138d repack: repack promisor objects if -a or -A is set
Currently, repack does not touch promisor packfiles at all, potentially
causing the performance of repositories that have many such packfiles to
drop. Therefore, repack all promisor objects if invoked with -a or -A.

This is done by an additional invocation of pack-objects on all promisor
objects individually given, which takes care of deduplication and allows
the resulting packfiles to respect flags such as --max-pack-size.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-09 09:17:39 -07:00
Jonathan Tan
cac1137dc4 list-objects: check if filter is NULL before using
In partial_clone_get_default_filter_spec(), the
core_partial_clone_filter_default variable may be NULL; ensure that it
is not NULL before using it.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-12 10:46:56 -07:00
Jonathan Tan
0c16cd499d gc: do not repack promisor packfiles
Teach gc to stop traversal at promisor objects, and to leave promisor
packfiles alone. This has the effect of only repacking non-promisor
packfiles, and preserves the distinction between promisor packfiles and
non-promisor packfiles.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-12-08 09:52:42 -08:00
Jonathan Tan
df11e19648 rev-list: support termination at promisor objects
Teach rev-list to support termination of an object traversal at any
object from a promisor remote (whether one that the local repo also has,
or one that the local repo knows about because it has another promisor
object that references it).

This will be used subsequently in gc and in the connectivity check used
by fetch.

For efficiency, if an object is referenced by a promisor object, and is
in the local repo only as a non-promisor object, object traversal will
not stop there. This is to avoid building the list of promisor object
references.

(In list-objects.c, the case where obj is NULL in process_blob() and
process_tree() do not need to be changed because those happen only when
there is a conflict between the expected type and the existing object.
If the object doesn't exist, an object will be synthesized, which is
fine.)

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-12-08 09:52:42 -08:00
Jonathan Tan
8b4c0103a9 sha1_file: support lazily fetching missing objects
Teach sha1_file to fetch objects from the remote configured in
extensions.partialclone whenever an object is requested but missing.

The fetching of objects can be suppressed through a global variable.
This is used by fsck and index-pack.

However, by default, such fetching is not suppressed. This is meant as a
temporary measure to ensure that all Git commands work in such a
situation. Future patches will update some commands to either tolerate
missing objects (without fetching them) or be more efficient in fetching
them.

In order to determine the code changes in sha1_file.c necessary, I
investigated the following:
 (1) functions in sha1_file.c that take in a hash, without the user
     regarding how the object is stored (loose or packed)
 (2) functions in packfile.c (because I need to check callers that know
     about the loose/packed distinction and operate on both differently,
     and ensure that they can handle the concept of objects that are
     neither loose nor packed)

(1) is handled by the modification to sha1_object_info_extended().

For (2), I looked at for_each_packed_object and others.  For
for_each_packed_object, the callers either already work or are fixed in
this patch:
 - reachable - only to find recent objects
 - builtin/fsck - already knows about missing objects
 - builtin/cat-file - warning message added in this commit

Callers of the other functions do not need to be changed:
 - parse_pack_index
   - http - indirectly from http_get_info_packs
   - find_pack_entry_one
     - this searches a single pack that is provided as an argument; the
       caller already knows (through other means) that the sought object
       is in a specific pack
 - find_sha1_pack
   - fast-import - appears to be an optimization to not store a file if
     it is already in a pack
   - http-walker - to search through a struct alt_base
   - http-push - to search through remote packs
 - has_sha1_pack
   - builtin/fsck - already knows about promisor objects
   - builtin/count-objects - informational purposes only (check if loose
     object is also packed)
   - builtin/prune-packed - check if object to be pruned is packed (if
     not, don't prune it)
   - revision - used to exclude packed objects if requested by user
   - diff - just for optimization

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-12-08 09:52:42 -08:00
Jonathan Tan
096c9b8be9 fsck: support promisor objects as CLI argument
Teach fsck to not treat missing promisor objects provided on the CLI as
an error when extensions.partialclone is set.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-12-05 09:46:05 -08:00
Jonathan Tan
caba7fc31a fsck: support referenced promisor objects
Teach fsck to not treat missing promisor objects indirectly pointed to
by refs as an error when extensions.partialclone is set.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-12-05 09:46:05 -08:00
Jonathan Tan
43f25158ca fsck: support refs pointing to promisor objects
Teach fsck to not treat refs referring to missing promisor objects as an
error when extensions.partialclone is set.

For the purposes of warning about no default refs, such refs are still
treated as legitimate refs.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-12-05 09:46:05 -08:00
Jonathan Tan
498f1f61f1 fsck: introduce partialclone extension
Currently, Git does not support repos with very large numbers of objects
or repos that wish to minimize manipulation of certain blobs (for
example, because they are very large) very well, even if the user
operates mostly on part of the repo, because Git is designed on the
assumption that every referenced object is available somewhere in the
repo storage. In such an arrangement, the full set of objects is usually
available in remote storage, ready to be lazily downloaded.

Teach fsck about the new state of affairs. In this commit, teach fsck
that missing promisor objects referenced from the reflog are not an
error case; in future commits, fsck will be taught about other cases.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-12-05 09:46:05 -08:00