This is a highly useful command, and we want it to get some testing "in
the wild". However, the patches have not yet been reviewed on the Git
mailing list, and are therefore subject to change. By marking the
command as experimental, users will be warned to pay attention to those
changes.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
The previous change introduced the '--[no-]sparse' option for the 'git
backfill' command, but did not assume it as enabled by default. However,
this is likely the behavior that users will most often want to happen.
Without this default, users with a small sparse-checkout may be confused
when 'git backfill' downloads every version of every object in the full
history.
However, this is left as a separate change so this decision can be reviewed
independently of the value of the '--[no-]sparse' option.
Add a test of adding the '--sparse' option to a repo without sparse-checkout
to make it clear that supplying it without a sparse-checkout is an error.
Signed-off-by: Derrick Stolee <stolee@gmail.com>
One way to significantly reduce the cost of a Git clone and later fetches is
to use a blobless partial clone and combine that with a sparse-checkout that
reduces the paths that need to be populated in the working directory. Not
only does this reduce the cost of clones and fetches, the sparse-checkout
reduces the number of objects needed to download from a promisor remote.
However, history investigations can be expensie as computing blob diffs will
trigger promisor remote requests for one object at a time. This can be
avoided by downloading the blobs needed for the given sparse-checkout using
'git backfill' and its new '--sparse' mode, at a time that the user is
willing to pay that extra cost.
Note that this is distinctly different from the '--filter=sparse:<oid>'
option, as this assumes that the partial clone has all reachable trees and
we are using client-side logic to avoid downloading blobs outside of the
sparse-checkout cone. This avoids the server-side cost of walking trees
while also achieving a similar goal. It also downloads in batches based on
similar path names, presenting a resumable download if things are
interrupted.
This augments the path-walk API to have a possibly-NULL 'pl' member that may
point to a 'struct pattern_list'. This could be more general than the
sparse-checkout definition at HEAD, but 'git backfill --sparse' is currently
the only consumer.
Be sure to test this in both cone mode and not cone mode. Cone mode has the
benefit that the path-walk can skip certain paths once they would expand
beyond the sparse-checkout.
Signed-off-by: Derrick Stolee <stolee@gmail.com>
Users may want to specify a minimum batch size for their needs. This is only
a minimum: the path-walk API provides a list of OIDs that correspond to the
same path, and thus it is optimal to allow delta compression across those
objects in a single server request.
We could consider limiting the request to have a maximum batch size in the
future.
Signed-off-by: Derrick Stolee <stolee@gmail.com>
The default behavior of 'git backfill' is to fetch all missing blobs that
are reachable from HEAD. Document and test this behavior.
The implementation is a very simple use of the path-walk API, initializing
the revision walk at HEAD to start the path-walk from all commits reachable
from HEAD. Ignore the object arrays that correspond to tree entries,
assuming that they are all present already.
Signed-off-by: Derrick Stolee <stolee@gmail.com>
In anticipation of implementing 'git backfill', populate the necessary files
with the boilerplate of a new builtin.
RFC TODO: When preparing this for a full implementation, make sure it is
based on the newest standards introduced by [1].
[1] https://lore.kernel.org/git/xmqqjzfq2f0f.fsf@gitster.g/T/#m606036ea2e75a6d6819d6b5c90e729643b0ff7f7
[PATCH 1/3] builtin: add a repository parameter for builtin functions
Signed-off-by: Derrick Stolee <stolee@gmail.com>
Adapting the implementation of ll_find_deltas(), create a threaded
version of the --path-walk compression step in 'git pack-objects'.
This involves adding a 'regions' member to the thread_params struct,
allowing each thread to own a section of paths. We can simplify the way
jobs are split because there is no value in extending the batch based on
name-hash the way sections of the object entry array are attempted to be
grouped. We re-use the 'list_size' and 'remaining' items for the purpose
of borrowing work in progress from other "victim" threads when a thread
has finished its batch of work more quickly.
Using the Git repository as a test repo, the p5313 performance test
shows that the resulting size of the repo is the same, but the threaded
implementation gives gains of varying degrees depending on the number of
objects being packed. (This was tested on a 16-core machine.)
Test HEAD~1 HEAD
-------------------------------------------------------------
5313.6: thin pack with --path-walk 0.01 0.01 +0.0%
5313.7: thin pack size with --path-walk 475 475 +0.0%
5313.12: big pack with --path-walk 1.99 1.87 -6.0%
5313.13: big pack size with --path-walk 14.4M 14.3M -0.4%
5313.18: repack with --path-walk 98.14 41.46 -57.8%
5313.19: repack size with --path-walk 197.2M 197.3M +0.0%
Signed-off-by: Derrick Stolee <stolee@gmail.com>
Previously, the --path-walk option to 'git pack-objects' would compute
deltas inline with the path-walk logic. This would make the progress
indicator look like it is taking a long time to enumerate objects, and
then very quickly computed deltas.
Instead of computing deltas on each region of objects organized by tree,
store a list of regions corresponding to these groups. These can later
be pulled from the list for delta compression before doing the "global"
delta search.
This presents a new progress indicator that can be used in tests to
verify that this stage is happening.
The current implementation is not integrated with threads, but could be
done in a future update.
Since we do not attempt to sort objects by size until after exploring
all trees, we can remove the previous change to t5530 due to a different
error message appearing first.
Signed-off-by: Derrick Stolee <stolee@gmail.com>
Users may want to enable the --path-walk option for 'git pack-objects' by
default, especially underneath commands like 'git push' or 'git repack'.
This should be limited to client repositories, since the --path-walk option
disables bitmap walks, so would be bad to include in Git servers when
serving fetches and clones. There is potential that it may be helpful to
consider when repacking the repository, to take advantage of improved deltas
across historical versions of the same files.
Much like how "pack.useSparse" was introduced and included in
"feature.experimental" before being enabled by default, use the repository
settings infrastructure to make the new "pack.usePathWalk" config enabled by
"feature.experimental" and "feature.manyFiles".
Signed-off-by: Derrick Stolee <stolee@gmail.com>
Since 'git pack-objects' supports a --path-walk option, allow passing it
through in 'git repack'. This presents interesting testing opportunities for
comparing the different repacking strategies against each other.
Add the --path-walk option to the performance tests in p5313.
For the microsoft/fluentui repo [1] checked out at a specific commit [2],
the results are very interesting:
Test this tree
------------------------------------------------------------------
5313.2: thin pack 0.40(0.47+0.04)
5313.3: thin pack size 1.2M
5313.4: thin pack with --full-name-hash 0.09(0.10+0.04)
5313.5: thin pack size with --full-name-hash 22.8K
5313.6: thin pack with --path-walk 0.08(0.06+0.02)
5313.7: thin pack size with --path-walk 20.8K
5313.8: big pack 2.16(8.43+0.23)
5313.9: big pack size 17.7M
5313.10: big pack with --full-name-hash 1.42(3.06+0.21)
5313.11: big pack size with --full-name-hash 18.0M
5313.12: big pack with --path-walk 2.21(8.39+0.24)
5313.13: big pack size with --path-walk 17.8M
5313.14: repack 98.05(662.37+2.64)
5313.15: repack size 449.1K
5313.16: repack with --full-name-hash 33.95(129.44+2.63)
5313.17: repack size with --full-name-hash 182.9K
5313.18: repack with --path-walk 106.21(121.58+0.82)
5313.19: repack size with --path-walk 159.6K
[1] https://github.com/microsoft/fluentui
[2] e70848ebac1cd720875bccaa3026f4a9ed700e08
This repo suffers from having a lot of paths that collide in the name
hash, so examining them in groups by path leads to better deltas. Also,
in this case, the single-threaded implementation is competitive with the
full repack. This is saving time diffing files that have significant
differences from each other.
A similar, but private, repo has even more extremes in the thin packs:
Test this tree
--------------------------------------------------------------
5313.2: thin pack 2.39(2.91+0.10)
5313.3: thin pack size 4.5M
5313.4: thin pack with --full-name-hash 0.29(0.47+0.12)
5313.5: thin pack size with --full-name-hash 15.5K
5313.6: thin pack with --path-walk 0.35(0.31+0.04)
5313.7: thin pack size with --path-walk 14.2K
Notice, however, that while the --full-name-hash version is working
quite well in these cases for the thin pack, it does poorly for some
other standard cases, such as this test on the Linux kernel repository:
Test this tree
--------------------------------------------------------------
5313.2: thin pack 0.01(0.00+0.00)
5313.3: thin pack size 310
5313.4: thin pack with --full-name-hash 0.00(0.00+0.00)
5313.5: thin pack size with --full-name-hash 1.4K
5313.6: thin pack with --path-walk 0.00(0.00+0.00)
5313.7: thin pack size with --path-walk 310
Here, the --full-name-hash option does much worse than the default name
hash, but the path-walk option does exactly as well.
Signed-off-by: Derrick Stolee <stolee@gmail.com>
There are many tests that validate whether 'git pack-objects' works as
expected. Instead of duplicating these tests, add a new test environment
variable, GIT_TEST_PACK_PATH_WALK, that implies --path-walk by default
when specified.
This was useful in testing the implementation of the --path-walk
implementation, especially in conjunction with test such as:
- t0411-clone-from-partial.sh : One test fetches from a repo that does
not have the boundary objects. This causes the path-based walk to
fail. Disable the variable for this test.
- t5306-pack-nobase.sh : Similar to t0411, one test fetches from a repo
without a boundary object.
- t5310-pack-bitmaps.sh : One test compares the case when packing with
bitmaps to the case when packing without them. Since we disable the
test variable when writing bitmaps, this causes a difference in the
object list (the --path-walk option adds an extra object). Specify
--no-path-walk in both processes for the comparison. Another test
checks for a specific delta base, but when computing dynamically
without using bitmaps, the base object it too small to be considered
in the delta calculations so no base is used.
- t5316-pack-delta-depth.sh : This script cares about certain delta
choices and their chain lengths. The --path-walk option changes how
these chains are selected, and thus changes the results of this test.
- t5322-pack-objects-sparse.sh : This demonstrates the effectiveness of
the --sparse option and how it combines with --path-walk.
- t5332-multi-pack-reuse.sh : This test verifies that the preferred
pack is used for delta reuse when possible. The --path-walk option is
not currently aware of the preferred pack at all, so finds a
different delta base.
- t7406-submodule-update.sh : When using the variable, the --depth
option collides with the --path-walk feature, resulting in a warning
message. Disable the variable so this warning does not appear.
I want to call out one specific test change that is only temporary:
- t5530-upload-pack-error.sh : One test cares specifically about an
"unable to read" error message. Since the current implementation
performs delta calculations within the path-walk API callback, a
different "unable to get size" error message appears. When this
is changed in a future refactoring, this test change can be reverted.
Signed-off-by: Derrick Stolee <stolee@gmail.com>
In order to more easily compute delta bases among objects that appear at the
exact same path, add a --path-walk option to 'git pack-objects'.
This option will use the path-walk API instead of the object walk given by
the revision machinery. Since objects will be provided in batches
representing a common path, those objects can be tested for delta bases
immediately instead of waiting for a sort of the full object list by
name-hash. This has multiple benefits, including avoiding collisions by
name-hash.
The objects marked as UNINTERESTING are included in these batches, so we
are guaranteeing some locality to find good delta bases.
After the individual passes are done on a per-path basis, the default
name-hash is used to find other opportunistic delta bases that did not
match exactly by the full path name.
RFC TODO: It is important to note that this option is inherently
incompatible with using a bitmap index. This walk probably also does not
work with other advanced features, such as delta islands.
Getting ahead of myself, this option compares well with --full-name-hash
when the packfile is large enough, but also performs at least as well as
the default in all cases that I've seen.
RFC TODO: this should probably be recording the batch locations to another
list so they could be processed in a second phase using threads.
RFC TODO: list some examples of how this outperforms previous pack-objects
strategies. (This is coming in later commits that include performance
test changes.)
Signed-off-by: Derrick Stolee <stolee@gmail.com>
This option is still under discussion on the Git mailing list.
We still would like to have some real-world data, and the best way to
get it is to get a Git for Windows release into users' hands so that
they can test it.
Nevertheless, without the official blessing of the Git maintainer, this
optionis experimental, and we need to be clear about that.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This also adds the '--full-name-hash' option introduced in the previous
change and adds newlines to the synopsis.
Signed-off-by: Derrick Stolee <stolee@gmail.com>
Add a new environment variable to opt-in to the --full-name-hash option
in 'git pack-objects'. This allows for extra testing of the feature
without repeating all of the test scenarios.
But this option isn't free. There are a few tests that change behavior
with the variable enabled.
First, there are a few tests that are very sensitive to certain delta
bases being picked. These are both involving the generation of thin
bundles and then counting their objects via 'git index-pack --fix-thin'
which pulls the delta base into the new packfile. For these tests,
disable the option as a decent long-term option.
Second, there are two tests in t5616-partial-clone.sh that I believe are
actually broken scenarios. While the client is set up to clone the
'promisor-server' repo via a treeless partial clone filter (tree:0),
that filter does not translate to the 'server' repo. Thus, fetching from
these repos causes the server to think that the client has all reachable
trees and blobs from the commits advertised as 'haves'. This leads the
server to providing a thin pack assuming those objects as delta bases.
Changing the name-hash algorithm presents new delta bases and thus
breaks the expectations of these tests. An alternative could be to set
up 'server' as a promisor server with the correct filter enabled. This
may also point out more issues with partial clone being set up as a
remote-based filtering mechanism and not a repository-wide setting. For
now, do the minimal change to make the test work by disabling the test
variable.
Signed-off-by: Derrick Stolee <stolee@gmail.com>
The pack_name_hash() method has not been materially changed since it was
introduced in ce0bd64299 (pack-objects: improve path grouping
heuristics., 2006-06-05). The intention here is to group objects by path
name, but also attempt to group similar file types together by making
the most-significant digits of the hash be focused on the final
characters.
Here's the crux of the implementation:
/*
* This effectively just creates a sortable number from the
* last sixteen non-whitespace characters. Last characters
* count "most", so things that end in ".c" sort together.
*/
while ((c = *name++) != 0) {
if (isspace(c))
continue;
hash = (hash >> 2) + (c << 24);
}
As the comment mentions, this only cares about the last sixteen
non-whitespace characters. This cause some filenames to collide more
than others. Here are some examples that I've seen while investigating
repositories that are growing more than they should be:
* "/CHANGELOG.json" is 15 characters, and is created by the beachball
[1] tool. Only the final character of the parent directory can
differntiate different versions of this file, but also only the two
most-significant digits. If that character is a letter, then this is
always a collision. Similar issues occur with the similar
"/CHANGELOG.md" path, though there is more opportunity for
differences in the parent directory.
* Localization files frequently have common filenames but differentiate
via parent directories. In C#, the name "/strings.resx.lcl" is used
for these localization files and they will all collide in name-hash.
[1] https://github.com/microsoft/beachball
I've come across many other examples where some internal tool uses a
common name across multiple directories and is causing Git to repack
poorly due to name-hash collisions.
It is clear that the existing name-hash algorithm is optimized for
repositories with short path names, but also is optimized for packing a
single snapshot of a repository, not a repository with many versions of
the same file. In my testing, this has proven out where the name-hash
algorithm does a good job of finding peer files as delta bases when
unable to use a historical version of that exact file.
However, for repositories that have many versions of most files and
directories, it is more important that the objects that appear at the
same path are grouped together.
Create a new pack_full_name_hash() method and a new --full-name-hash
option for 'git pack-objects' to call that method instead. Add a simple
pass-through for 'git repack --full-name-hash' for additional testing in
the context of a full repack, where I expect this will be most
effective.
The hash algorithm is as simple as possible to be reasonably effective:
for each character of the path string, add a multiple of that character
and a large prime number (chosen arbitrarily, but intended to be large
relative to the size of a uint32_t). Then, shift the current hash value
to the right by 5, with overlap. The addition and shift parameters are
standard mechanisms for creating hard-to-predict behaviors in the bits
of the resulting hash.
This is not meant to be cryptographic at all, but uniformly distributed
across the possible hash values. This creates a hash that appears
pseudorandom. There is no ability to consider similar file types as
being close to each other.
In a later change, a test-tool will be added so the effectiveness of
this hash can be demonstrated directly.
For now, let's consider how effective this mechanism is when repacking a
repository with and without the --full-name-hash option. Specifically,
let's use 'git repack -adf [--full-name-hash]' as our test.
On the Git repository, we do not expect much difference. All path names
are short. This is backed by our results:
| Stage | Pack Size | Repack Time |
|-----------------------|-----------|-------------|
| After clone | 260 MB | N/A |
| Standard Repack | 127MB | 106s |
| With --full-name-hash | 126 MB | 99s |
This example demonstrates how there is some natural overhead coming from
the cloned copy because the server is hosting many forks and has not
optimized for exactly this set of reachable objects. But the full repack
has similar characteristics with and without --full-name-hash.
However, we can test this in a repository that uses one of the
problematic naming conventions above. The fluentui [2] repo uses
beachball to generate CHANGELOG.json and CHANGELOG.md files, and these
files have very poor delta characteristics when comparing against
versions across parent directories.
| Stage | Pack Size | Repack Time |
|-----------------------|-----------|-------------|
| After clone | 694 MB | N/A |
| Standard Repack | 438 MB | 728s |
| With --full-name-hash | 168 MB | 142s |
[2] https://github.com/microsoft/fluentui
In this example, we see significant gains in the compressed packfile
size as well as the time taken to compute the packfile.
Using a collection of repositories that use the beachball tool, I was
able to make similar comparisions with dramatic results. While the
fluentui repo is public, the others are private so cannot be shared for
reproduction. The results are so significant that I find it important to
share here:
| Repo | Standard Repack | With --full-name-hash |
|----------|-----------------|-----------------------|
| fluentui | 438 MB | 168 MB |
| Repo B | 6,255 MB | 829 MB |
| Repo C | 37,737 MB | 7,125 MB |
| Repo D | 130,049 MB | 6,190 MB |
Future changes could include making --full-name-hash implied by a config
value or even implied by default during a full repack.
Signed-off-by: Derrick Stolee <stolee@gmail.com>
Fix performance regression of a recent "fatten promisor pack with
local objects" protection against an unwanted gc.
* jt/fix-fattening-promisor-fetch:
index-pack --promisor: also check commits' trees
index-pack --promisor: don't check blobs
index-pack --promisor: dedup before checking links
"git tag" has been taught to refuse to create refs/tags/HEAD
as such a tag will be confusing in the context of UI provided by
the Git Porcelain commands.
* jc/forbid-head-as-tagname:
tag: "git tag" refuses to use HEAD as a tagname
t5604: do not expect that HEAD can be a valid tagname
refs: drop strbuf_ prefix from helpers
refs: move ref name helpers around
"git describe" optimization.
* jk/describe-perf:
describe: split "found all tags" and max_candidates logic
describe: stop traversing when we run out of names
describe: stop digging for max_candidates+1
t/perf: add tests for git-describe
t6120: demonstrate weakness in disjoint-root handling
Yet another "pass the repository through the callchain" topic.
* kn/midx-wo-the-repository:
midx: inline the `MIDX_MIN_SIZE` definition
midx: pass down `hash_algo` to functions using global variables
midx: pass `repository` to `load_multi_pack_index`
midx: cleanup internal usage of `the_repository` and `the_hash_algo`
midx-write: pass down repository to `write_midx_file[_only]`
write-midx: add repository field to `write_midx_context`
midx-write: use `revs->repo` inside `read_refs_snapshot`
midx-write: pass down repository to static functions
packfile.c: remove unnecessary prepare_packed_git() call
midx: add repository to `multi_pack_index` struct
config: make `packed_git_(limit|window_size)` non-global variables
config: make `delta_base_cache_limit` a non-global variable
packfile: pass down repository to `for_each_packed_object`
packfile: pass down repository to `has_object[_kept]_pack`
packfile: pass down repository to `odb_pack_name`
packfile: pass `repository` to static function in the file
packfile: use `repository` from `packed_git` directly
packfile: add repository to struct `packed_git`
"git fast-import" learned to reject paths with ".." and "." as
their components to avoid creating invalid tree objects.
* en/fast-import-verify-path:
t9300: test verification of renamed paths
fast-import: disallow more path components
fast-import: disallow "." and ".." path components
"git bundle --unbundle" and "git clone" running on a bundle file
both learned to trigger fsck over the new objects with configurable
fck check levels.
* jt/bundle-fsck:
transport: propagate fsck configuration during bundle fetch
fetch-pack: split out fsck config parsing
bundle: support fsck message configuration
bundle: add bundle verification options type
Loosen overly strict ownership check introduced in the recent past,
to keep the promise "cloning a suspicious repository is a safe
first step to inspect it".
* bc/allow-upload-pack-from-other-people:
Allow cloning from repositories owned by another user
Commit c08589efdc (index-pack: repack local links into promisor packs,
2024-11-01) seems to contain an oversight in that the tree of a commit
is not checked. Teach git to check these trees.
The fix slows down a fetch from a certain repo at $DAYJOB from 2m2.127s
to 2m45.052s, but in order to make the fetch correct, it seems worth it.
In order to test this, we could create server and client repos as
follows...
C S
\ /
O
(O and C are commits both on the client and server. S is a commit
only on the server. C and S have the same tree but different commit
messages. The diff between O and C is non-zero.)
...and then, from the client, fetch S from the server.
In theory, the client declares "have C" and the server can use this
information to exclude S's tree (since it knows that the client has C's
tree, which is the same as S's tree). However, it is also possible for
the server to compute that it needs to send S and not O, and proceed
from there; therefore the objects of C are not considered at all when
determining what to send in the packfile. In order to prevent a test of
client functionality from having such a dependence on server behavior, I
have not included such a test.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
As a follow-up to the parent of this commit, it was found that not
checking for the existence of blobs linked from trees sped up the fetch
from 24m47.815s to 2m2.127s. Teach Git to do that.
The tradeoff of not checking blobs is documented in a code comment.
(Blobs may also be linked from tag objects, but it is impossible to know
the type of an object linked from a tag object without looking it up in
the object database, so the code for that is untouched.)
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commit c08589efdc (index-pack: repack local links into promisor packs,
2024-11-01) fixed a bug with what was believed to be a negligible
decrease in performance [1] [2]. But at $DAYJOB, with at least one repo,
it was found that the decrease in performance was very significant.
Looking at the patch, whenever we parse an object in the packfile to
be indexed, we check the targets of all its outgoing links for its
existence. However, this could be optimized by first collecting all such
targets into an oidset (thus deduplicating them) before checking. Teach
Git to do that.
On a certain fetch from the aforementioned repo, this improved
performance from approximately 7 hours to 24m47.815s. This number will
be further reduced in a subsequent patch.
[1] https://lore.kernel.org/git/CAG1j3zGiNMbri8rZNaF0w+yP+6OdMz0T8+8_Wgd1R_p1HzVasg@mail.gmail.com/
[2] https://lore.kernel.org/git/20241105212849.3759572-1-jonathantanmy@google.com/
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commit a30154187a (describe: stop traversing when we run out of names,
2024-10-31) taught git-describe to automatically reduce the
max_candidates setting to match the total number of possible names. This
lets us break out of the traversal rather than fruitlessly searching for
more candidates when there are no more to be found.
However, setting max_candidates to 0 (e.g., if the repo has no tags)
overlaps with the --exact-match option, which explicitly uses the same
value. And this causes a regression with --always, which is ignored in
exact-match mode. We used to get this in a repo with no tags:
$ git describe --always HEAD
b2f0a7f
and now we get:
$ git describe --always HEAD
fatal: no tag exactly matches 'b2f0a7f47f5f2aebe1e7fceff19a57de20a78c06'
The reason is that we bail early in describe_commit() when
max_candidates is set to 0. This logic goes all the way back to
2c33f75754 (Teach git-describe --exact-match to avoid expensive tag
searches, 2008-02-24).
We should obviously fix this regression, but there are two paths,
depending on what you think:
$ git describe --always --exact-match
and
$ git describe --always --candidates=0
should do. Since the "--always" option was added, it has always been
ignored in --exact-match (or --candidates=0) mode. I.e., we treat
--exact-match as a true exact match of a tag, and never fall back to
using --always, even if it was requested.
If we think that's a bug (or at least a misfeature), then the right
solution is to fix it by removing the early bail-out from 2c33f75754,
letting the noop algorithm run and then hitting the --always fallback
output. And then our regression naturally goes away, because it follows
the same path.
If we think that the current "--exact-match --always" behavior is the
right thing, then we have to differentiate the case where we
automatically reduced max_candidates to 0 from the case where the user
asked for it specifically. That's possible to do with a flag, but we can
also just reimplement the logic from a30154187a to explicitly break out
of the traversal when we run out of candidates (rather than relying on
the existing max_candidates check).
My gut feeling is along the lines of option 1 (it's a bug, and people
would be happy for "--exact-match --always" to give the fallback rather
than ignoring "--always"). But the documentation can be interpreted in
the other direction, and we've certainly lived with the existing
behavior for many years. So it's possible that changing it now is the
wrong thing.
So this patch fixes the regression by taking the second option,
retaining the "--exact-match" behavior as-is. There are two new tests.
The first shows that the regression is fixed (we don't even need a new
repo without tags; a restrictive --match is enough to create the
situation that there are no candidate names).
The second test confirms that the "--exact-match --always" behavior
remains unchanged and continues to die when there is no tag pointing at
the specified commit. It's possible we may reconsider this in the
future, but this shows that the approach described above is implemented
faithfully.
We can also run the perf tests in p6100 to see that we've retained the
speedup that a30154187a was going for:
Test HEAD^ HEAD
--------------------------------------------------------------------------------------
6100.2: describe HEAD 0.72(0.64+0.07) 0.72(0.66+0.06) +0.0%
6100.3: describe HEAD with one max candidate 0.01(0.00+0.00) 0.01(0.00+0.00) +0.0%
6100.4: describe HEAD with one tag 0.01(0.01+0.00) 0.01(0.01+0.00) +0.0%
Reported-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In a previous commit, we passed the repository field to all
subcommands in the `builtin/` directory. Utilize this to pass the
repository field down to the `write_midx_file[_only]` functions to
remove the usage of `the_repository` global variables.
With this, all usage of global variables in `midx-write.c` is removed,
hence, remove the `USE_THE_REPOSITORY_VARIABLE` guard from the file.
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* kn/pass-repo-to-builtin-sub-sub-commands:
builtin: pass repository to sub commands
Git 2.47.1
Makefile(s): avoid recipe prefix in conditional statements
doc: switch links to https
doc: update links to current pages
The eleventh batch
pack-objects: only perform verbatim reuse on the preferred pack
t5332-multi-pack-reuse.sh: demonstrate duplicate packing failure
test-lib: move malloc-debug setup after $PATH setup
builtin/difftool: intialize some hashmap variables
refspec: store raw refspecs inside refspec_item
refspec: drop separate raw_nr count
fetch: adjust refspec->raw_nr when filtering prefetch refspecs
test-lib: check malloc debug LD_PRELOAD before using
* kn/the-repository:
packfile.c: remove unnecessary prepare_packed_git() call
midx: add repository to `multi_pack_index` struct
config: make `packed_git_(limit|window_size)` non-global variables
config: make `delta_base_cache_limit` a non-global variable
packfile: pass down repository to `for_each_packed_object`
packfile: pass down repository to `has_object[_kept]_pack`
packfile: pass down repository to `odb_pack_name`
packfile: pass `repository` to static function in the file
packfile: use `repository` from `packed_git` directly
packfile: add repository to struct `packed_git`
Built-in Git subcommands are supplied the repository object to work
with; they learned to do the same when they invoke sub-subcommands.
* kn/pass-repo-to-builtin-sub-sub-commands:
builtin: pass repository to sub commands
"git fsck" learned to issue warnings on "curiously formatted" ref
contents that have always been taken valid but something Git
wouldn't have written itself (e.g., missing terminating end-of-line
after the full object name).
* sj/ref-contents-check:
ref: add symlink ref content check for files backend
ref: check whether the target of the symref is a ref
ref: add basic symref content check for files backend
ref: add more strict checks for regular refs
ref: port git-fsck(1) regular refs check for files backend
ref: support multiple worktrees check for refs
ref: initialize ref name outside of check functions
ref: check the full refname instead of basename
ref: initialize "fsck_ref_report" with zero
The migration procedure between two ref backends has been optimized.
* ps/ref-backend-migration-optim:
reftable: rename scratch buffer
refs: adapt `initial_transaction` flag to be unsigned
reftable/block: optimize allocations by using scratch buffer
reftable/block: rename `block_writer::buf` variable
reftable/writer: optimize allocations by using a scratch buffer
refs: don't normalize log messages with `REF_SKIP_CREATE_REFLOG`
refs: skip collision checks in initial transactions
refs: use "initial" transaction semantics to migrate refs
refs/files: support symbolic and root refs in initial transaction
refs: introduce "initial" transaction flag
refs/files: move logic to commit initial transaction
refs: allow passing flags when setting up a transaction
Leakfixes.
* ps/leakfixes-part-10: (27 commits)
t: remove TEST_PASSES_SANITIZE_LEAK annotations
test-lib: unconditionally enable leak checking
t: remove unneeded !SANITIZE_LEAK prerequisites
t: mark some tests as leak free
t5601: work around leak sanitizer issue
git-compat-util: drop now-unused `UNLEAK()` macro
global: drop `UNLEAK()` annotation
t/helper: fix leaking commit graph in "read-graph" subcommand
builtin/branch: fix leaking sorting options
builtin/init-db: fix leaking directory paths
builtin/help: fix leaks in `check_git_cmd()`
help: fix leaking return value from `help_unknown_cmd()`
help: fix leaking `struct cmdnames`
help: refactor to not use globals for reading config
builtin/sparse-checkout: fix leaking sanitized patterns
split-index: fix memory leak in `move_cache_to_base_index()`
git: refactor builtin handling to use a `struct strvec`
git: refactor alias handling to use a `struct strvec`
strvec: introduce new `strvec_splice()` function
line-log: fix leak when rewriting commit parents
...
Give a bit of advice/hint message when "git maintenance" stops finding a
lock file left by another instance that still is potentially running.
* ps/gc-stale-lock-warning:
t7900: fix host-dependent behaviour when testing git-maintenance(1)
builtin/gc: provide hint when maintenance hits a stale schedule lock
The variables `packed_git_window_size` and `packed_git_limit` are global
config variables used in the `packfile.c` file. Since it is only used in
this file, let's change it from being a global config variable to a
local variable for the subsystem.
With this, we rid `packfile.c` from all global variable usage and this
means we can also remove the `USE_THE_REPOSITORY_VARIABLE` guard from
the file.
Helped-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `delta_base_cache_limit` variable is a global config variable used
by multiple subsystems. Let's make this non-global, by adding this
variable independently to the subsystems where it is used.
First, add the setting to the `repo_settings` struct, this provides
access to the config in places where the repository is available. Use
this in `packfile.c`.
In `index-pack.c` we add it to the `pack_idx_option` struct and its
constructor. While the repository struct is available here, it may not
be set because `git index-pack` can be used without a repository.
In `gc.c` add it to the `gc_config` struct and also the constructor
function. The gc functions currently do not have direct access to a
repository struct.
These changes are made to remove the usage of `delta_base_cache_limit`
as a global variable in `packfile.c`. This brings us one step closer to
removing the `USE_THE_REPOSITORY_VARIABLE` definition in `packfile.c`
which we complete in the next patch.
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The function `for_each_packed_object` currently relies on the global
variable `the_repository`. To eliminate global variable usage in
`packfile.c`, we should progressively shift the dependency on
the_repository to higher layers. Let's remove its usage from this
function and closely related function `is_promisor_object`.
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The functions `has_object[_kept]_pack` currently rely on the global
variable `the_repository`. To eliminate global variable usage in
`packfile.c`, we should progressively shift the dependency on
the_repository to higher layers. Let's remove its usage from these
functions and any related ones.
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The function `odb_pack_name` currently relies on the global variable
`the_repository`. To eliminate global variable usage in `packfile.c`, we
should progressively shift the dependency on the_repository to higher
layers.
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The struct `packed_git` holds information regarding a packed object
file. Let's add the repository variable to this object, to represent the
repository that this packfile belongs to. This helps remove dependency
on the global `the_repository` object in `packfile.c` by simply using
repository information now readily available in the struct.
We do need to consider that a packfile could be part of the alternates
of a repository, but considering that we only have one repository struct
and also that we currently anyways use 'the_repository', we should be
OK with this change.
We also modify `alloc_packed_git` to ensure that the repository is added
to newly created `packed_git` structs. This requires modifying the
function and all its callee to pass the repository object down the
levels.
Helped-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The helper functions (strbuf_branchname, strbuf_check_branch_ref,
and strbuf_check_tag_ref) are about handling branch and tag names,
and it is a non-essential fact that these functions use strbuf to
hold these names. Rename them to make it clarify that these are
more about "ref".
Signed-off-by: Junio C Hamano <gitster@pobox.com>
strbuf_branchname(), strbuf_check_{branch,tag}_ref() are helper
functions to deal with branch and tag names, and the fact that they
happen to use strbuf to hold the name of a branch or a tag is not
essential. These functions fit better in the refs API than strbuf
API, the latter of which is about string manipulations.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Instead of just disallowing '.' and '..', make use of verify_path() to
ensure that fast-import will disallow anything we wouldn't allow into
the index, such as anything under .git/, .gitmodules as a symlink, or
a dos drive prefix on Windows.
Since a few fast-export and fast-import tests that tried to stress-test
the correct handling of quoting relied on filenames that fail
is_valid_win32_path(), such as spaces or periods at the end of filenames
or backslashes within the filename, turn off core.protectNTFS for those
tests to ensure they keep passing.
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This teaches the `worktree repair` command to respect the
`--[no-]relative-paths` CLI option and `worktree.useRelativePaths`
config setting. If an existing worktree with an absolute path is repaired
with `--relative-paths`, the links will be replaced with relative paths,
even if the original path was correct. This allows a user to covert
existing worktrees between absolute/relative as desired.
To simplify things, both linking files are written when one of the files
needs to be repaired. In some cases, this fixes the other file before it
is checked, in other cases this results in a correct file being written
with the same contents.
Signed-off-by: Caleb White <cdwhite3@pm.me>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This teaches the `worktree move` command to respect the
`--[no-]relative-paths` CLI option and `worktree.useRelativePaths`
config setting. If an existing worktree is moved with `--relative-paths`
the new path will be relative (and visa-versa).
Signed-off-by: Caleb White <cdwhite3@pm.me>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This introduces the `--[no-]relative-paths` CLI option and
`worktree.useRelativePaths` configuration setting to the `worktree add`
command. When enabled these options allow worktrees to be linked using
relative paths, enhancing portability across environments where absolute
paths may differ (e.g., containerized setups, shared network drives).
Git still creates absolute paths by default, but these options allow
users to opt-in to relative paths if desired.
The t2408 test file is removed and more comprehensive tests are
written for the various worktree operations in their own files.
Signed-off-by: Caleb White <cdwhite3@pm.me>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When `unbundle()` is invoked, fsck verification may be configured by
passing the `VERIFY_BUNDLE_FSCK` flag. This mechanism allows fsck checks
on the bundle to be enabled or disabled entirely. To facilitate more
fine-grained fsck configuration, additional context must be provided to
`unbundle()`.
Introduce the `unbundle_opts` type, which wraps the existing
`verify_bundle_flags`, to facilitate future extension of `unbundle()`
configuration. Also update `unbundle()` and its call sites to accept
this new options type instead of the flags directly. The end behavior is
functionally the same, but allows for the set of configurable options to
be extended. This is leveraged in a subsequent commit to enable fsck
message severity configuration.
Signed-off-by: Justin Tobler <jltobler@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
