"git pack-objects" and its wrapper "git repack" learned an option
to use an alternative path-hash function to improve delta-base
selection to produce a packfile with deeper history than window
size.
* ds/name-hash-tweaks:
pack-objects: prevent name hash version change
test-tool: add helper for name-hash values
p5313: add size comparison test
pack-objects: add GIT_TEST_NAME_HASH_VERSION
repack: add --name-hash-version option
pack-objects: add --name-hash-version option
pack-objects: create new name-hash function version
Adapt callers to use generic hash context helpers instead of using the
hash algorithm to update them. This makes the callsites easier to reason
about and removes the possibility that the wrong hash algorithm is used
to update the hash context's state. And as a nice side effect this also
gets rid of a bunch of users of `the_hash_algo`.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We generally avoid using `typedef` in the Git codebase. One exception
though is the `git_hash_ctx`, likely because it used to be a union
rather than a struct until the preceding commit refactored it. But now
that it is a normal `struct` there isn't really a need for a typedef
anymore.
Drop the typedef and adapt all callers accordingly.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* tb/unsafe-hash-cleanup:
hash.h: drop unsafe_ function variants
csum-file: introduce hashfile_checkpoint_init()
t/helper/test-hash.c: use unsafe_hash_algo()
csum-file.c: use unsafe_hash_algo()
hash.h: introduce `unsafe_hash_algo()`
csum-file.c: extract algop from hashfile_checksum_valid()
csum-file: store the hash algorithm as a struct field
t/helper/test-tool: implement sha1-unsafe helper
Introduce a new API to visit objects in batches based on a common
path, or by type.
* ds/path-walk-1:
path-walk: drop redundant parse_tree() call
path-walk: reorder object visits
path-walk: mark trees and blobs as UNINTERESTING
path-walk: visit tags and cached objects
path-walk: allow consumer to specify object types
t6601: add helper for testing path-walk API
test-lib-functions: add test_cmp_sorted
path-walk: introduce an object walk by path
The help text from "git $cmd -h" appear on the standard output for
some $cmd and the standard error for others. The built-in commands
have been fixed to show them on the standard output consistently.
* jc/show-usage-help:
builtin: send usage() help text to standard output
oddballs: send usage() help text to standard output
builtins: send usage_with_options() help text to standard output
usage: add show_usage_if_asked()
parse-options: add show_usage_with_options_if_asked()
t0012: optionally check that "-h" output goes to stdout
Add a new test-tool helper, name-hash, to output the value of the
name-hash algorithms for the input list of strings, one per line.
Since the name-hash values can be stored in the .bitmap files, it is
important that these hash functions do not change across Git versions.
Add a simple test to t5310-pack-bitmaps.sh to provide some testing of
the current values. Due to how these functions are implemented, it would
be difficult to change them without disturbing these values. The paths
used for this test are carefully selected to demonstrate some of the
behavior differences of the two current name hash versions, including
which conditions will cause them to collide.
Create a performance test that uses test_size to demonstrate how
collisions occur for these hash algorithms. This test helps inform
someone as to the behavior of the name-hash algorithms for their repo
based on the paths at HEAD.
My copy of the Git repository shows modest statistics around the
collisions of the default name-hash algorithm:
Test this tree
--------------------------------------------------
5314.1: paths at head 4.5K
5314.2: distinct hash value: v1 4.1K
5314.3: maximum multiplicity: v1 13
5314.4: distinct hash value: v2 4.2K
5314.5: maximum multiplicity: v2 9
Here, the maximum collision multiplicity is 13, but around 10% of paths
have a collision with another path.
In a more interesting example, the microsoft/fluentui [1] repo had these
statistics at time of committing:
Test this tree
--------------------------------------------------
5314.1: paths at head 19.5K
5314.2: distinct hash value: v1 8.2K
5314.3: maximum multiplicity: v1 279
5314.4: distinct hash value: v2 17.8K
5314.5: maximum multiplicity: v2 44
[1] https://github.com/microsoft/fluentui
That demonstrates that of the nearly twenty thousand path names, they
are assigned around eight thousand distinct values. 279 paths are
assigned to a single value, leading the packing algorithm to sort
objects from those paths together, by size.
With the v2 name hash function, the maximum multiplicity lowers to 44,
leaving some room for further improvement.
In a more extreme example, an internal monorepo had a much worse
collision rate:
Test this tree
--------------------------------------------------
5314.1: paths at head 227.3K
5314.2: distinct hash value: v1 72.3K
5314.3: maximum multiplicity: v1 14.4K
5314.4: distinct hash value: v2 166.5K
5314.5: maximum multiplicity: v2 138
Here, we can see that the v2 name hash function provides somem
improvements, but there are still a number of collisions that could lead
to repacking problems at this scale.
Signed-off-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Remove a series of conditionals within the shared cmd_hash_impl() helper
that powers the 'sha1' and 'sha1-unsafe' helpers.
Instead, replace them with a single conditional that transforms the
specified hash algorithm into its unsafe variant. Then all subsequent
calls can directly use whatever function it wants to call without having
to decide between the safe and unsafe variants.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
With the new "unsafe" SHA-1 build knob, it is convenient to have a
test-tool that can exercise Git's unsafe SHA-1 wrappers for testing,
similar to 't/helper/test-tool sha1'.
Implement that helper by altering the implementation of that test-tool
(in cmd_hash_impl(), which is generic and parameterized over different
hash functions) to conditionally run the unsafe variants of the chosen
hash function, and expose the new behavior via a new 'sha1-unsafe' test
helper.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
More code paths have a repository passed through the callchain,
instead of assuming the primary the_repository object.
* ps/the-repository:
match-trees: stop using `the_repository`
graph: stop using `the_repository`
add-interactive: stop using `the_repository`
tmp-objdir: stop using `the_repository`
resolve-undo: stop using `the_repository`
credential: stop using `the_repository`
mailinfo: stop using `the_repository`
diagnose: stop using `the_repository`
server-info: stop using `the_repository`
send-pack: stop using `the_repository`
serve: stop using `the_repository`
trace: stop using `the_repository`
pager: stop using `the_repository`
progress: stop using `the_repository`
The code to compute "unique" name used git_rand() which can fail or
get stuck; the callsite does not require cryptographic security.
Introduce the "insecure" mode and use it appropriately.
* ps/reftable-get-random-fix:
reftable/stack: accept insecure random bytes
wrapper: allow generating insecure random bytes
Using the show_usage_with_options_if_asked() helper we introduced
earlier, fix callers of usage_with_options() that want to show the
help text when explicitly asked by the end-user. The help text now
goes to the standard output stream for them.
The test in t7600 for "git merge -h" may want to be retired, as the
same is covered by t0012 already, but it is specifically testing that
the "-h" option gets a response even with a corrupt index file, so
for now let's leave it there.
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `csprng_bytes()` function generates randomness and writes it into a
caller-provided buffer. It abstracts over a couple of implementations,
where the exact one that is used depends on the platform.
These implementations have different guarantees: while some guarantee to
never fail (arc4random(3)), others may fail. There are two significant
failures to distinguish from one another:
- Systemic failure, where e.g. opening "/dev/urandom" fails or when
OpenSSL doesn't have a provider configured.
- Entropy failure, where the entropy pool is exhausted, and thus the
function cannot guarantee strong cryptographic randomness.
While we cannot do anything about the former, the latter failure can be
acceptable in some situations where we don't care whether or not the
randomness can be predicted.
Introduce a new `CSPRNG_BYTES_INSECURE` flag that allows callers to opt
into weak cryptographic randomness. The exact behaviour of the flag
depends on the underlying implementation:
- `arc4random_buf()` never returns an error, so it doesn't change.
- `getrandom()` pulls from "/dev/urandom" by default, which never
blocks on modern systems even when the entropy pool is empty.
- `getentropy()` seems to block when there is not enough randomness
available, and there is no way of changing that behaviour.
- `GtlGenRandom()` doesn't mention anything about its specific
failure mode.
- The fallback reads from "/dev/urandom", which also returns bytes in
case the entropy pool is drained in modern Linux systems.
That only leaves OpenSSL with `RAND_bytes()`, which returns an error in
case the returned data wouldn't be cryptographically safe. This function
is replaced with a call to `RAND_pseudo_bytes()`, which can indicate
whether or not the returned data is cryptographically secure via its
return value. If it is insecure, and if the `CSPRNG_BYTES_INSECURE` flag
is set, then we ignore the insecurity and return the data regardless.
It is somewhat questionable whether we really need the flag in the first
place, or whether we wouldn't just ignore the potentially-insecure data.
But the risk of doing that is that we might have or grow callsites that
aren't aware of the potential insecureness of the data in places where
it really matters. So using a flag to opt-in to that behaviour feels
like the more secure choice.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The functions `repo_get_merge_bases_many()` and friends accepts an array
of commits as well as a parameter that indicates how large that array
is. This parameter is using a signed integer, which leads to a couple of
warnings with -Wsign-compare.
Refactor the code to use `size_t` to track indices instead and adapt
callers accordingly. While most callers are trivial, there are two
callers that require a bit more scrutiny:
- builtin/merge-base.c:show_merge_base() subtracts `1` from the
`rev_nr` before calling `repo_get_merge_bases_many_dirty()`, so if
the variable was `0` it would wrap. This code is fine though because
its only caller will execute that code only when `argc >= 2`, and it
follows that `rev_nr >= 2`, as well.
- bisect.ccheck_merge_bases() similarly subtracts `1` from `rev_nr`.
Again, there is only a single caller that populates `rev_nr` with
`good_revs.nr`. And because a bisection always requires at least one
good revision it follws that `rev_nr >= 1`.
Mark the file as -Wsign-compare-clean.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Start working to make the codebase buildable with -Wsign-compare.
* ps/build-sign-compare:
t/helper: don't depend on implicit wraparound
scalar: address -Wsign-compare warnings
builtin/patch-id: fix type of `get_one_patchid()`
builtin/blame: fix type of `length` variable when emitting object ID
gpg-interface: address -Wsign-comparison warnings
daemon: fix type of `max_connections`
daemon: fix loops that have mismatching integer types
global: trivial conversions to fix `-Wsign-compare` warnings
pkt-line: fix -Wsign-compare warning on 32 bit platform
csum-file: fix -Wsign-compare warning on 32-bit platform
diff.h: fix index used to loop through unsigned integer
config.mak.dev: drop `-Wno-sign-compare`
global: mark code units that generate warnings with `-Wsign-compare`
compat/win32: fix -Wsign-compare warning in "wWinMain()"
compat/regex: explicitly ignore "-Wsign-compare" warnings
git-compat-util: introduce macros to disable "-Wsign-compare" warnings
When the input rev_info has UNINTERESTING starting points, we want to be
sure that the UNINTERESTING flag is passed appropriately through the
objects. To match how this is done in places such as 'git pack-objects', we
use the mark_edges_uninteresting() method.
This method has an option for using the "sparse" walk, which is similar in
spirit to the path-walk API's walk. To be sure to keep it independent, add a
new 'prune_all_uninteresting' option to the path_walk_info struct.
To check how the UNINTERSTING flag is spread through our objects, extend the
'test-tool path-walk' command to output whether or not an object has that
flag. This changes our tests significantly, including the removal of some
objects that were previously visited due to the incomplete implementation.
Signed-off-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The rev_info that is specified for a path-walk traversal may specify
visiting tag refs (both lightweight and annotated) and also may specify
indexed objects (blobs and trees). Update the path-walk API to walk
these objects as well.
When walking tags, we need to peel the annotated objects until reaching
a non-tag object. If we reach a commit, then we can add it to the
pending objects to make sure we visit in the commit walk portion. If we
reach a tree, then we will assume that it is a root tree. If we reach a
blob, then we have no good path name and so add it to a new list of
"tagged blobs".
When the rev_info includes the "--indexed-objects" flag, then the
pending set includes blobs and trees found in the cache entries and
cache-tree. The cache entries are usually blobs, though they could be
trees in the case of a sparse index. The cache-tree stores
previously-hashed tree objects but these are cleared out when staging
objects below those paths. We add tests that demonstrate this.
The indexed objects come with a non-NULL 'path' value in the pending
item. This allows us to prepopulate the 'path_to_lists' strmap with
lists for these paths.
The tricky thing about this walk is that we will want to combine the
indexed objects walk with the commit walk, especially in the future case
of walking objects during a command like 'git repack'.
Whenever possible, we want the objects from the index to be grouped with
similar objects in history. We don't want to miss any paths that appear
only in the index and not in the commit history.
Thus, we need to be careful to let the path stack be populated initially
with only the root tree path (and possibly tags and tagged blobs) and go
through the normal depth-first search. Afterwards, if there are other
paths that are remaining in the paths_to_lists strmap, we should then
iterate through the stack and visit those objects recursively.
Signed-off-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We add the ability to filter the object types in the path-walk API so
the callback function is called fewer times.
This adds the ability to ask for the commits in a list, as well. We
re-use the empty string for this set of objects because these are passed
directly to the callback function instead of being part of the
'path_stack'.
Future changes will add the ability to visit annotated tags.
Signed-off-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add some tests based on the current behavior, doing interesting checks
for different sets of branches, ranges, and the --boundary option. This
sets a baseline for the behavior and we can extend it as new options are
introduced.
Store and output a 'batch_nr' value so we can demonstrate that the paths are
grouped together in a batch and not following some other ordering. This
allows us to test the depth-first behavior of the path-walk API. However, we
purposefully do not test the order of the objects in the batch, so the
output is compared to the expected output through a sort.
It is important to mention that the behavior of the API will change soon as
we start to handle UNINTERESTING objects differently, but these tests will
demonstrate the change in behavior.
Signed-off-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Stop using `the_repository` in the "serve" subsystem by passing in a
repository when advertising capabilities or serving requests.
Adjust callers accordingly by using `the_repository`. While there may be
some callers that have a repository available in their context, this
trivial conversion allows for easier verification and bubbles up the use
of `the_repository` by one level.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Stop using `the_repository` in the "progress" subsystem by passing in a
repository when initializing `struct progress`. Furthermore, store a
pointer to the repository in that struct so that we can pass it to the
trace2 API when logging information.
Adjust callers accordingly by using `the_repository`. While there may be
some callers that have a repository available in their context, this
trivial conversion allows for easier verification and bubbles up the use
of `the_repository` by one level.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* ps/build-sign-compare:
t/helper: don't depend on implicit wraparound
scalar: address -Wsign-compare warnings
builtin/patch-id: fix type of `get_one_patchid()`
builtin/blame: fix type of `length` variable when emitting object ID
gpg-interface: address -Wsign-comparison warnings
daemon: fix type of `max_connections`
daemon: fix loops that have mismatching integer types
global: trivial conversions to fix `-Wsign-compare` warnings
pkt-line: fix -Wsign-compare warning on 32 bit platform
csum-file: fix -Wsign-compare warning on 32-bit platform
diff.h: fix index used to loop through unsigned integer
config.mak.dev: drop `-Wno-sign-compare`
global: mark code units that generate warnings with `-Wsign-compare`
compat/win32: fix -Wsign-compare warning in "wWinMain()"
compat/regex: explicitly ignore "-Wsign-compare" warnings
git-compat-util: introduce macros to disable "-Wsign-compare" warnings
Build procedure update plus introduction of Meson based builds.
* ps/build: (24 commits)
Introduce support for the Meson build system
Documentation: add comparison of build systems
t: allow overriding build dir
t: better support for out-of-tree builds
Documentation: extract script to generate a list of mergetools
Documentation: teach "cmd-list.perl" about out-of-tree builds
Documentation: allow sourcing generated includes from separate dir
Makefile: simplify building of templates
Makefile: write absolute program path into bin-wrappers
Makefile: allow "bin-wrappers/" directory to exist
Makefile: refactor generators to be PWD-independent
Makefile: extract script to generate gitweb.js
Makefile: extract script to generate gitweb.cgi
Makefile: extract script to massage Python scripts
Makefile: extract script to massage Shell scripts
Makefile: use "generate-perl.sh" to massage Perl library
Makefile: extract script to massage Perl scripts
Makefile: consistently use PERL_PATH
Makefile: generate doc versions via GIT-VERSION-GEN
Makefile: generate "git.rc" via GIT-VERSION-GEN
...
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`
Isolates the reftable subsystem from the rest of Git's codebase by
using fewer pieces of Git's infrastructure.
* ps/reftable-detach:
reftable/system: provide thin wrapper for lockfile subsystem
reftable/stack: drop only use of `get_locked_file_path()`
reftable/system: provide thin wrapper for tempfile subsystem
reftable/stack: stop using `fsync_component()` directly
reftable/system: stop depending on "hash.h"
reftable: explicitly handle hash format IDs
reftable/system: move "dir.h" to its only user
Introduce support for the Meson build system, a "modern" meta build
system that supports many different platforms, including Linux, macOS,
Windows and BSDs. Meson supports different backends, including Ninja,
Xcode and Microsoft Visual Studio. Several common IDEs provide an
integration with it.
The biggest contender compared to Meson is probably CMake as outlined in
our "Documentation/technical/build-systems.txt" file. Based on my own
personal experience from working with both build systems extensively I
strongly favor Meson over CMake. In my opinion, it feels significantly
easier to use with a syntax that feels more like a "real" programming
language. The second big reason is that Meson supports Rust natively,
which may prove to be important given that the project may pick up Rust
as another language eventually.
Using Meson is rather straight-forward. An example:
```
# Meson uses out-of-tree builds. You can set up multiple build
# directories, how you name them is completely up to you.
$ mkdir build
$ cd build
$ meson setup .. -Dprefix=/tmp/git-installation
# Build the project. This also provides several other targets like
e.g. `install` or `test`.
$ ninja
# Meson has been wired up to support execution of our test suites.
# Both our unit tests and our integration tests are supported.
# Running `meson test` without any arguments will execute all tests,
# but the syntax supports globbing to select only some tests.
$ meson test 't-*'
# Execute single test interactively to allow for debugging.
$ meson test 't0000-*' --interactive --test-args=-ix
```
The build instructions have been successfully tested on the following
systems, tests are passing:
- Apple macOS 10.15.
- FreeBSD 14.1.
- NixOS 24.11.
- OpenBSD 7.6.
- Ubuntu 24.04.
- Windows 10 with Cygwin.
- Windows 10 with MinGW64, except for t9700, which is also broken with
our Makefile.
- Windows 10 with Visual Studio 2022 toolchain, using the Native Tools
Command Prompt with `meson setup --vsenv`. Tests pass, except for
t9700.
- Windows 10 with Visual Studio 2022 solution, using the Native Tools
Command Prompt with `meson setup --backend vs2022`. Tests pass,
except for t9700.
- Windows 10 with VS Code, using the Meson plug-in.
It is expected that there will still be rough edges in the current
version. If this patch lands the expectation is that it will coexist
with our other build systems for a while. Like this, distributions can
slowly migrate over to Meson and report any findings they have to us
such that we can continue to iterate. A potential cutoff date for other
build systems may be Git 3.0.
Some notes:
- The installed distribution is structured somewhat differently than
how it used to be the case. All of our binaries are installed into
`$libexec/git-core`, while all binaries part of `$bindir` are now
symbolic links pointing to the former. This rule is consistent in
itself and thus easier to reason about.
- We do not install dashed binaries into `$libexec/git-core` anymore,
so there won't e.g. be a symlink for git-add(1). These are not
required by modern Git and there isn't really much of a use case for
those anymore. By not installing those symlinks we thus start the
deprecation of this layout.
- We're targeting Meson 1.3.0, which has been released relatively
recently November 2023. The only feature we use from that version is
`fs.relative_to()`, which we could replace if necessary. If so, we
could start to target Meson 1.0.0 and newer, released in December
2022.
- The whole build instructions count around 3300 lines, half of which
is listing all of our code and test files. Our Makefiles are around
5000 lines, autoconf adds another 1300 lines. CMake in comparison
has only 1200 linescode, but it avoids listing individual files and
does not wire up auto-configuration as extensively as the Meson
instructions do.
- We bundle a set of subproject wrappers for curl, expat, openssl,
pcre2 and zlib. This allows developers to build Git without these
dependencies preinstalled, and Meson will fetch and build them
automatically. This is especially helpful on Windows.
Helped-by: Eli Schwartz <eschwartz@gentoo.org>
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In our test helpers we have two cases where we assign -1 to an `unsigned
long`. The intent is to essentially mean "unbounded output", which is
achieved via implicit wraparound of the value.
This pattern causes warnings with -Wsign-compare though. Adapt it and
instead use `ULONG_MAX` explicitly.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We have a bunch of loops which iterate up to an unsigned boundary using
a signed index, which generates warnigs because we compare a signed and
unsigned value in the loop condition. Address these sites for trivial
cases and enable `-Wsign-compare` warnings for these code units.
This patch only adapts those code units where we can drop the
`DISABLE_SIGN_COMPARE_WARNINGS` macro in the same step.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `struct diff_flags` structure is essentially an array of flags, all
of which have the same type. We can thus use `sizeof()` to iterate
through all of the flags, which we do in `diff_flags_or()`. But while
the statement returns an unsigned integer, we used a signed integer to
iterate through the flags, which generates a warning.
Fix this by using `size_t` for the index instead.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Mark code units that generate warnings with `-Wsign-compare`. This
allows for a structured approach to get rid of all such warnings over
time in a way that can be easily measured.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `load_multi_pack_index` function in midx uses `the_repository`
variable to access the `repository` struct. Modify the function and its
callee's to send the `repository` field.
This moves usage of `the_repository` to the `test-read-midx.c` file.
While that is not optimal, it is okay, since the upcoming commits will
slowly move the usage of `the_repository` up the layers and remove it
eventually.
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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
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
In 9b1cb5070f (builtin: add a repository parameter for builtin
functions, 2024-09-13) the repository was passed down to all builtin
commands. This allowed the repository to be passed down to lower layers
without depending on the global `the_repository` variable.
Continue this work by also passing down the repository parameter from
the command to sub-commands. This will help pass down the repository to
other subsystems and cleanup usage of global variables like
'the_repository' and 'the_hash_algo'.
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We're leaking the commit-graph in the "test-helper read-graph"
subcommand, but as the leak is annotated with `UNLEAK()` the leak
sanitizer doesn't complain.
Fix the leak by calling `free_commit_graph()`. Besides getting rid of
the `UNLEAK()` annotation, it also increases code coverage because we
properly release resources as Git would do it, as well.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Reference transactions use `refs_verify_refname_available()` to check
for colliding references. This check consists of two parts:
- Checks for whether multiple ref updates in the same transaction
conflict with each other.
- Checks for whether existing refs conflict with any refs part of the
transaction.
While we generally cannot avoid the first check, the second check is
superfluous in cases where the transaction is an initial one in an
otherwise empty ref store. The check results in multiple ref reads as
well as the creation of a ref iterator for every ref we're checking,
which adds up quite fast when performing the check for many refs.
Introduce a new flag that allows us to skip this check and wire it up in
such that the backends pass it when running an initial transaction. This
leads to significant speedups when migrating ref storage backends. From
"files" to "reftable":
Benchmark 1: migrate files:reftable (refcount = 100000, revision = HEAD~)
Time (mean ± σ): 472.4 ms ± 6.7 ms [User: 175.9 ms, System: 285.2 ms]
Range (min … max): 463.5 ms … 483.2 ms 10 runs
Benchmark 2: migrate files:reftable (refcount = 100000, revision = HEAD)
Time (mean ± σ): 86.1 ms ± 1.9 ms [User: 67.9 ms, System: 16.0 ms]
Range (min … max): 82.9 ms … 90.9 ms 29 runs
Summary
migrate files:reftable (refcount = 100000, revision = HEAD) ran
5.48 ± 0.15 times faster than migrate files:reftable (refcount = 100000, revision = HEAD~)
And from "reftable" to "files":
Benchmark 1: migrate reftable:files (refcount = 100000, revision = HEAD~)
Time (mean ± σ): 452.7 ms ± 3.4 ms [User: 209.9 ms, System: 235.4 ms]
Range (min … max): 445.9 ms … 457.5 ms 10 runs
Benchmark 2: migrate reftable:files (refcount = 100000, revision = HEAD)
Time (mean ± σ): 95.2 ms ± 2.2 ms [User: 73.6 ms, System: 20.6 ms]
Range (min … max): 91.7 ms … 100.8 ms 28 runs
Summary
migrate reftable:files (refcount = 100000, revision = HEAD) ran
4.76 ± 0.11 times faster than migrate reftable:files (refcount = 100000, revision = HEAD~)
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We include "hash.h" in "reftable/system.h" such that we can use hash
format IDs as well as the raw size of SHA1 and SHA256. As we are in the
process of converting the reftable library to become standalone we of
course cannot rely on those constants anymore.
Introduce a new `enum reftable_hash` to replace internal uses of the
hash format IDs and new constants that replace internal uses of the hash
size. Adapt the reftable backend to set up the correct hash function.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We never release the local `struct strbuf base` buffer, thus leaking
memory. Fix this leak.
This leak is exposed by t7063, but plugging it alone does not make the
whole test suite pass.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
While "common-main.c" already initializes `the_repository` for us, we do
so a second time in the "read-cache" test helper. This causes a memory
leak because the old repository's contents isn't released.
Stop calling `initialize_repository()` to plug this leak.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The "reach" test tool doesn't bother to clean up any of its allocated
resources, causing various leaks. Plug them.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The main function we use to search a pack index for an object is
find_pack_entry_one(). That function still takes a bare pointer to the
hash, despite the fact that its underlying bsearch_pack() function needs
an object_id struct. And so we end up making an extra copy of the hash
into the struct just to do a lookup.
As it turns out, all callers but one already have such an object_id. So
we can just take a pointer to that struct and use it directly. This
avoids the extra copy and provides a more type-safe interface.
The one exception is get_delta_base() in packfile.c, when we are chasing
a REF_DELTA from inside the pack (and thus we have a pointer directly to
the mmap'd pack memory, not a struct). We can just bump the hashcpy()
from inside find_pack_entry_one() to this one caller that needs it.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
The reftable library is now prepared to expect that the memory
allocation function given to it may fail to allocate and to deal
with such an error.
* ps/reftable-alloc-failures: (26 commits)
reftable/basics: fix segfault when growing `names` array fails
reftable/basics: ban standard allocator functions
reftable: introduce `REFTABLE_FREE_AND_NULL()`
reftable: fix calls to free(3P)
reftable: handle trivial allocation failures
reftable/tree: handle allocation failures
reftable/pq: handle allocation failures when adding entries
reftable/block: handle allocation failures
reftable/blocksource: handle allocation failures
reftable/iter: handle allocation failures when creating indexed table iter
reftable/stack: handle allocation failures in auto compaction
reftable/stack: handle allocation failures in `stack_compact_range()`
reftable/stack: handle allocation failures in `reftable_new_stack()`
reftable/stack: handle allocation failures on reload
reftable/reader: handle allocation failures in `reader_init_iter()`
reftable/reader: handle allocation failures for unindexed reader
reftable/merged: handle allocation failures in `merged_table_init_iter()`
reftable/writer: handle allocation failures in `reftable_new_writer()`
reftable/writer: handle allocation failures in `writer_index_hash()`
reftable/record: handle allocation failures when decoding records
...
Handle allocation failures in `merged_table_init_iter()`. While at it,
merge `merged_iter_init()` into the function. It only has a single
caller and merging them makes it easier to handle allocation failures
consistently.
This change also requires us to adapt `reftable_stack_init_*_iterator()`
to bubble up the new error codes of `merged_table_iter_init()`. Adapt
callsites accordingly.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
