A test in reftable library has been rewritten using the unit test
framework.
* cp/unit-test-reftable-record:
t-reftable-record: add tests for reftable_log_record_compare_key()
t-reftable-record: add tests for reftable_ref_record_compare_name()
t-reftable-record: add index tests for reftable_record_is_deletion()
t-reftable-record: add obj tests for reftable_record_is_deletion()
t-reftable-record: add log tests for reftable_record_is_deletion()
t-reftable-record: add ref tests for reftable_record_is_deletion()
t-reftable-record: add comparison tests for obj records
t-reftable-record: add comparison tests for index records
t-reftable-record: add comparison tests for ref records
t-reftable-record: add reftable_record_cmp() tests for log records
t: move reftable/record_test.c to the unit testing framework
helper/test-oidmap.c along with t0016-oidmap.sh test the oidmap.h
library which is built on top of hashmap.h.
Migrate them to the unit testing framework for better performance,
concise code and better debugging. Along with the migration also plug
memory leaks and make the test logic independent for all the tests.
The migration removes 'put' tests from t0016, because it is used as
setup to all the other tests, so testing it separately does not yield
any benefit.
Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored-by: Kaartic Sivaraam <kaartic.sivaraam@gmail.com>
Reviewed-by: Josh Steadmon <steadmon@google.com>
Helped-by: Phillip Wood <phillip.wood123@gmail.com>
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Ghanshyam Thakkar <shyamthakkar001@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
reftable/record_test.c exercises the functions defined in
reftable/record.{c, h}. Migrate reftable/record_test.c to the
unit testing framework. Migration involves refactoring the tests
to use the unit testing framework instead of reftable's test
framework, and renaming the tests to fit unit-tests' naming scheme.
While at it, change the type of index variable 'i' to 'size_t'
from 'int'. This is because 'i' is used in comparison against
'ARRAY_SIZE(x)' which is of type 'size_t'.
Also, use set_hash() which is defined locally in the test file
instead of set_test_hash() which is defined by
reftable/test_framework.{c, h}. This is fine to do as both these
functions are similarly implemented, and
reftable/test_framework.{c, h} is not #included in the ported test.
Get rid of reftable_record_print() from the tests as well, because
it clutters the test framework's output and we have no way of
verifying the output.
Mentored-by: Patrick Steinhardt <ps@pks.im>
Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Chandra Pratap <chandrapratap3519@gmail.com>
Acked-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The pseudo-merge reachability bitmap to help more efficient storage
of the reachability bitmap in a repository with too many refs has
been added.
* tb/pseudo-merge-reachability-bitmap: (26 commits)
pack-bitmap.c: ensure pseudo-merge offset reads are bounded
Documentation/technical/bitmap-format.txt: add missing position table
t/perf: implement performance tests for pseudo-merge bitmaps
pseudo-merge: implement support for finding existing merges
ewah: `bitmap_equals_ewah()`
pack-bitmap: extra trace2 information
pack-bitmap.c: use pseudo-merges during traversal
t/test-lib-functions.sh: support `--notick` in `test_commit_bulk()`
pack-bitmap: implement test helpers for pseudo-merge
ewah: implement `ewah_bitmap_popcount()`
pseudo-merge: implement support for reading pseudo-merge commits
pack-bitmap.c: read pseudo-merge extension
pseudo-merge: scaffolding for reads
pack-bitmap: extract `read_bitmap()` function
pack-bitmap-write.c: write pseudo-merge table
pseudo-merge: implement support for selecting pseudo-merge commits
config: introduce `git_config_double()`
pack-bitmap: make `bitmap_writer_push_bitmapped_commit()` public
pack-bitmap: implement `bitmap_writer_has_bitmapped_object_id()`
pack-bitmap-write: support storing pseudo-merge commits
...
To help developers, the build procedure now allows builders to use
CFLAGS_APPEND to specify additional CFLAGS.
* ps/make-append-to-cflags:
Makefile: add ability to append to CFLAGS and LDFLAGS
A new command has been added to migrate a repository that uses the
files backend for its ref storage to use the reftable backend, with
limitations.
* ps/ref-storage-migration:
builtin/refs: new command to migrate ref storage formats
refs: implement logic to migrate between ref storage formats
refs: implement removal of ref storages
worktree: don't store main worktree twice
reftable: inline `merged_table_release()`
refs/files: fix NULL pointer deref when releasing ref store
refs/files: extract function to iterate through root refs
refs/files: refactor `add_pseudoref_and_head_entries()`
refs: allow to skip creation of reflog entries
refs: pass storage format to `ref_store_init()` explicitly
refs: convert ref storage format to an enum
setup: unset ref storage when reinitializing repository version
"make check-docs" noticed problems and reported to its output but
failed to signal its findings with its exit status, which has been
corrected.
* ps/check-docs-fix:
ci/test-documentation: work around SyntaxWarning in Python 3.12
gitlab-ci: add job to run `make check-docs`
Documentation/lint-manpages: bubble up errors
Makefile: extract script to lint missing/extraneous manpages
A test helper that essentially is unit tests on the "decorate"
logic has been rewritten using the unit-tests framework.
* gt/decorate-unit-test:
t/: migrate helper/test-example-decorate to the unit testing framework
A pair of test helpers that essentially are unit tests on hash
algorithms have been rewritten using the unit-tests framework.
* gt/t-hash-unit-test:
t/: migrate helper/test-{sha1, sha256} to unit-tests/t-hash
strbuf: introduce strbuf_addstrings() to repeatedly add a string
Basic unit tests for reftable have been reimplemented under the
unit test framework.
* cp/reftable-unit-test:
t: improve the test-case for parse_names()
t: add test for put_be16()
t: move tests from reftable/record_test.c to the new unit test
t: move tests from reftable/stack_test.c to the new unit test
t: move reftable/basics_test.c to the unit testing framework
helper/test-oidtree.c along with t0069-oidtree.sh test the oidtree.h
library, which is a wrapper around crit-bit tree. Migrate them to
the unit testing framework for better debugging and runtime
performance. Along with the migration, add an extra check for
oidtree_each() test, which showcases how multiple expected matches can
be given to check_each() helper.
To achieve this, introduce a new library called 'lib-oid.h'
exclusively for the unit tests to use. It currently mainly includes
utility to generate object_id from an arbitrary hex string
(i.e. '12a' -> '12a0000000000000000000000000000000000000'). This also
handles the hash algo selection based on GIT_TEST_DEFAULT_HASH.
This library will also be helpful when we port other unit tests such
as oid-array, oidset etc.
Helped-by: Junio C Hamano <gitster@pobox.com>
Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored-by: Kaartic Sivaraam <kaartic.sivaraam@gmail.com>
Signed-off-by: Ghanshyam Thakkar <shyamthakkar001@gmail.com>
[jc: small fixlets squashed in]
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are some usecases where we may want to append CFLAGS to the
default CFLAGS set by Git. This could for example be to enable or
disable specific compiler warnings or to change the optimization level
that code is compiled with. This cannot be done without overriding the
complete CFLAGS value though and thus requires the user to redeclare the
complete defaults used by Git.
Introduce a new variable `CFLAGS_APPEND` that gets appended to the
default value of `CFLAGS`. As compiler options are last-one-wins, this
fulfills both of the usecases mentioned above. It's also common practice
across many other projects to have such a variable.
While at it, also introduce a matching `LDFLAGS_APPEND` variable. While
there isn't really any need for this variable as there are no default
`LDFLAGS`, users may expect this variable to exist, as well.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Leakfixes.
* ps/leakfixes:
builtin/mv: fix leaks for submodule gitfile paths
builtin/mv: refactor to use `struct strvec`
builtin/mv duplicate string list memory
builtin/mv: refactor `add_slash()` to always return allocated strings
strvec: add functions to replace and remove strings
submodule: fix leaking memory for submodule entries
commit-reach: fix memory leak in `ahead_behind()`
builtin/credential: clear credential before exit
config: plug various memory leaks
config: clarify memory ownership in `git_config_string()`
builtin/log: stop using globals for format config
builtin/log: stop using globals for log config
convert: refactor code to clarify ownership of check_roundtrip_encoding
diff: refactor code to clarify memory ownership of prefixes
config: clarify memory ownership in `git_config_pathname()`
http: refactor code to clarify memory ownership
checkout: clarify memory ownership in `unique_tracking_name()`
strbuf: fix leak when `appendwholeline()` fails with EOF
transport-helper: fix leaking helper name
Introduce a new command that allows the user to migrate a repository
between ref storage formats. This new command is implemented as part of
a new git-refs(1) executable. This is due to two reasons:
- There is no good place to put the migration logic in existing
commands. git-maintenance(1) felt unwieldy, and git-pack-refs(1) is
not the correct place to put it, either.
- I had it in my mind to create a new low-level command for accessing
refs for quite a while already. git-refs(1) is that command and can
over time grow more functionality relating to refs. This should help
discoverability by consolidating low-level access to refs into a
single executable.
As mentioned in the preceding commit that introduces the ref storage
format migration logic, the new `git refs migrate` command still has a
bunch of restrictions. These restrictions are documented accordingly.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The "check-docs" target of our top-level Makefile fulfills two different
roles. For one it runs the "lint-docs" target of the "Documentation/"
Makefile. And second it performs some checks of whether there are any
manpages that are missing or extraneous via some inline scripts.
The second set of checks feels quite misplaced in the top-level Makefile
as it would fit in much better with our "lint-docs" target. Back when
the checks were introduced in 8c989ec528 (Makefile: $(MAKE) check-docs,
2006-04-13), that target did not yet exist though.
Furthermore, the script makes use of several Makefile variables which
are defined in the top-level Makefile, which makes it hard to access
their contents from elsewhere. There is a trick though that we already
use in "check-builtins.sh" to gain access: we can create an ad-hoc
Makefile that has an extra target to print those variables.
Pull out the script into a separate "lint-manpages.sh" script by using
that trick. Wire up that script via the "lint-docs" target. For one,
normal shell scripts are way easier to reason about than those which are
embedded in a Makefile. Second, it allows one to easily execute the
script standalone without any of the other checks.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The strcmp-offset tests have been rewritten using the unit test
framework.
* gt/unit-test-strcmp-offset:
t/: port helper/test-strcmp-offset.c to unit-tests/t-strcmp-offset.c
reftable/basics_test.c exercise the functions defined in
reftable/basics.{c, h}. Migrate reftable/basics_test.c to the
unit testing framework. Migration involves refactoring the tests
to use the unit testing framework instead of reftable's test
framework.
Mentored-by: Patrick Steinhardt <ps@pks.im>
Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Chandra Pratap <chandrapratap3519@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
t/helper/test-{sha1, sha256} and t/t0015-hash.sh test the hash
implementation of SHA-1 and SHA-256 in Git with basic hash values.
Migrate them to the new unit testing framework for better debugging
and runtime performance.
The 'sha1' and 'sha256' subcommands are still not removed due to
pack_trailer():lib-pack.sh's reliance on them. The 'sha1' subcommand
is also relied upon by t0013-sha1dc (which requires 'test-tool
sha1' dying when it is used on a file created to contain the
known sha1 attack).
Helped-by: Patrick Steinhardt <ps@pks.im>
Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored-by: Kaartic Sivaraam <kaartic.sivaraam@gmail.com>
Co-authored-by: Achu Luma <ach.lumap@gmail.com>
Signed-off-by: Achu Luma <ach.lumap@gmail.com>
Signed-off-by: Ghanshyam Thakkar <shyamthakkar001@gmail.com>
Acked-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
helper/test-example-decorate.c along with t9004-example.sh provide
an example of how to use the functions in decorate.h (which provides
a data structure that associates Git objects to void pointers) and
also test their output.
Migrate them to the new unit testing framework for better debugging
and runtime performance.
Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored-by: Kaartic Sivaraam <kaartic.sivaraam@gmail.com>
Signed-off-by: Ghanshyam Thakkar <shyamthakkar001@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add two functions that allow to replace and remove strings contained in
the strvec. This will be used by a subsequent commit that refactors
git-mv(1).
While at it, add a bunch of unit tests that cover both old and new
functionality.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a new (empty) header file to contain the implementation for
selecting, reading, and applying pseudo-merge bitmaps.
For now this header and its corresponding implementation are left
empty, but they will evolve over the course of subsequent commit(s).
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The trailer API has been reshuffled a bit.
* la/hide-trailer-info:
trailer unit tests: inspect iterator contents
trailer: document parse_trailers() usage
trailer: retire trailer_info_get() from API
trailer: make trailer_info struct private
trailer: make parse_trailers() return trailer_info pointer
interpret-trailers: access trailer_info with new helpers
sequencer: use the trailer iterator
trailer: teach iterator about non-trailer lines
trailer: add unit tests for trailer iterator
Makefile: sort UNIT_TEST_PROGRAMS
In the recent codebase update (8bf6fbd (Merge branch
'js/doc-unit-tests', 2023-12-09)), a new unit testing framework was
merged, providing a standardized approach for testing C code. Prior to
this update, some unit tests relied on the test helper mechanism,
lacking a dedicated unit testing framework. It's more natural to perform
these unit tests using the new unit test framework.
Let's migrate the unit tests for strcmp-offset functionality from the
legacy approach using the test-tool command `test-tool strcmp-offset` in
helper/test-strcmp-offset.c to the new unit testing framework
(t/unit-tests/test-lib.h).
The migration involves refactoring the tests to utilize the testing
macros provided by the framework (TEST() and check_*()).
Helped-by: Patrick Steinhardt <ps@pks.im>
Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored-by: Kaartic Sivaraam <kaartic.sivaraam@gmail.com>
Co-authored-by: Achu Luma <ach.lumap@gmail.com>
Signed-off-by: Achu Luma <ach.lumap@gmail.com>
Signed-off-by: Ghanshyam Thakkar <shyamthakkar001@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The "test-tool" has been taught to run testsuite tests in parallel,
bypassing the need to use the "prove" tool.
* js/unit-test-suite-runner:
cmake: let `test-tool` run the unit tests, too
ci: use test-tool as unit test runner on Windows
t/Makefile: run unit tests alongside shell tests
unit tests: add rule for running with test-tool
test-tool run-command testsuite: support unit tests
test-tool run-command testsuite: remove hardcoded filter
test-tool run-command testsuite: get shell from env
t0080: turn t-basic unit test into a helper
Code to write out reftable has seen some optimization and
simplification.
* ps/reftable-write-optim:
reftable/block: reuse compressed array
reftable/block: reuse zstream when writing log blocks
reftable/writer: reset `last_key` instead of releasing it
reftable/writer: unify releasing memory
reftable/writer: refactorings for `writer_flush_nonempty_block()`
reftable/writer: refactorings for `writer_add_record()`
refs/reftable: don't recompute committer ident
reftable: remove name checks
refs/reftable: skip duplicate name checks
refs/reftable: perform explicit D/F check when writing symrefs
refs/reftable: fix D/F conflict error message on ref copy
In the previous commit, we added support in test-tool for running
collections of unit tests. Now, add rules in t/Makefile for running in
this way.
This new rule can be executed from the top-level Makefile via
`make DEFAULT_UNIT_TEST_TARGET=unit-tests-test-tool unit-tests`, or by
setting DEFAULT_UNIT_TEST_TARGET in config.mak.
Signed-off-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
While t/unit-tests/t-basic.c uses the unit-test framework added in
e137fe3b29 (unit tests: add TAP unit test framework, 2023-11-09), it is
not a true unit test in that it intentionally fails in order to exercise
various codepaths in the unit-test framework. Thus, we intentionally
exclude it when running unit tests through the various t/Makefile
targets. Instead, it is executed by t0080-unit-test-output.sh, which
verifies its output follows the TAP format expected for the various
pass, skip, or fail cases.
As such, it makes more sense for t-basic to be a helper item for
t0080-unit-test-output.sh, so let's move it to
t/helper/test-example-tap.c and adjust Makefiles as necessary.
Signed-off-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Test the number of trailers found by the iterator (to be more precise,
the parsing mechanism which the iterator just walks over) when given
some arbitrary log message.
We test the iterator because it is a public interface function exposed
by the trailer API (we generally don't want to test internal
implementation details which are, unlike the API, subject to drastic
changes).
Signed-off-by: Linus Arver <linus@ucla.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In addition to building the objects needed, try to link the objects
that are used in fuzzer tests, to make sure at least they build
without bitrot, in Linux CI runs.
* js/build-fuzz-more-often:
fuzz: link fuzz programs with `make all` on Linux
Since 5e47215080 (fuzz: add basic fuzz testing target., 2018-10-12), we
have compiled object files for the fuzz tests as part of the default
'make all' target. This helps prevent bit-rot in lesser-used parts of
the codebase, by making sure that incompatible changes are caught at
build time.
However, since we never linked the fuzzer executables, this did not
protect us from link-time errors. As of 8b9a42bf48 (fuzz: fix fuzz test
build rules, 2024-01-19), it's now possible to link the fuzzer
executables without using a fuzzing engine and a variety of
compiler-specific (and compiler-version-specific) flags, at least on
Linux. So let's add a platform-specific option in config.mak.uname to
link the executables as part of the default `make all` target.
Since linking the fuzzer executables without a fuzzing engine does not
require a C++ compiler, we can change the FUZZ_PROGRAMS build rule to
use $(CC) by default. This avoids compiler mis-match issues when
overriding $(CC) but not $(CXX). When we *do* want to actually link with
a fuzzing engine, we can set $(FUZZ_CXX). The build instructions in the
CI fuzz-smoke-test job and in the Makefile comment have been updated
accordingly.
While we're at it, we can consolidate some of the fuzzer build
instructions into one location in the Makefile.
Suggested-by: Junio C Hamano <gitster@pobox.com>
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Adjust to an upcoming changes to GNU make that breaks our Makefiles.
* tb/make-indent-conditional-with-non-spaces:
Makefile(s): do not enforce "all indents must be done with tab"
Makefile(s): avoid recipe prefix in conditional statements
In the preceding commit we have disabled name checks in the "reftable"
backend. These checks were responsible for verifying multiple things
when writing records to the reftable stack:
- Detecting file/directory conflicts. Starting with the preceding
commits this is now handled by the reftable backend itself via
`refs_verify_refname_available()`.
- Validating refnames. This is handled by `check_refname_format()` in
the generic ref transacton layer.
The code in the reftable library is thus not used anymore and likely to
bitrot over time. Remove it.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In GNU Make commit 07fcee35 ([SV 64815] Recipe lines cannot contain
conditional statements, 2023-05-22) and following, conditional
statements may no longer be preceded by a tab character (which Make
refers to as the recipe prefix).
There are a handful of spots in our various Makefile(s) which will break
in a future release of Make containing 07fcee35. For instance, trying to
compile the pre-image of this patch with the tip of make.git results in
the following:
$ make -v | head -1 && make
GNU Make 4.4.90
config.mak.uname:842: *** missing 'endif'. Stop.
The kernel addressed this issue in 82175d1f9430 (kbuild: Replace tabs
with spaces when followed by conditionals, 2024-01-28). Address the
issues in Git's tree by applying the same strategy.
When a conditional word (ifeq, ifneq, ifdef, etc.) is preceded by one or
more tab characters, replace each tab character with 8 space characters
with the following:
find . -type f -not -path './.git/*' -name Makefile -or -name '*.mak' |
xargs perl -i -pe '
s/(\t+)(ifn?eq|ifn?def|else|endif)/" " x (length($1) * 8) . $2/ge unless /\\$/
'
The "unless /\\$/" removes any false-positives (like "\telse \"
appearing within a shell script as part of a recipe).
After doing so, Git compiles on newer versions of Make:
$ make -v | head -1 && make
GNU Make 4.4.90
GIT_VERSION = 2.44.0.414.gfac1dc44ca9
[...]
$ echo $?
0
Reported-by: Dario Gjorgjevski <dario.gjorgjevski@gmail.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce a new midx-write.c source file, which holds all of the
functionality from the MIDX sub-system related to writing new MIDX files.
Similar to the relationship between "pack-bitmap.c" and
"pack-bitmap-write.c", this source file will hold code that is specific
to writing MIDX files as opposed to reading them (the latter will remain
in midx.c).
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Work to support a repository that work with both SHA-1 and SHA-256
hash algorithms has started.
* eb/hash-transition: (30 commits)
t1016-compatObjectFormat: add tests to verify the conversion between objects
t1006: test oid compatibility with cat-file
t1006: rename sha1 to oid
test-lib: compute the compatibility hash so tests may use it
builtin/ls-tree: let the oid determine the output algorithm
object-file: handle compat objects in check_object_signature
tree-walk: init_tree_desc take an oid to get the hash algorithm
builtin/cat-file: let the oid determine the output algorithm
rev-parse: add an --output-object-format parameter
repository: implement extensions.compatObjectFormat
object-file: update object_info_extended to reencode objects
object-file-convert: convert commits that embed signed tags
object-file-convert: convert commit objects when writing
object-file-convert: don't leak when converting tag objects
object-file-convert: convert tag objects when writing
object-file-convert: add a function to convert trees between algorithms
object: factor out parse_mode out of fast-import and tree-walk into in object.h
cache: add a function to read an OID of a specific algorithm
tag: sign both hashes
commit: export add_header_signature to support handling signatures on tags
...
Add a new fuzz target that exercises the parsing of git configs.
The existing git_config_from_mem function is a perfect entry point
for fuzzing as it exercises the same code paths as the rest of the
config parsing functions and offers an easily fuzzable interface.
Config parsing is a useful thing to fuzz because it operates on user
controlled data and is a central component of many git operations.
Signed-off-by: Brian C Tracy <brian.tracy33@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Integrate the reftable code into the refs framework as a backend.
* ps/reftable-backend:
refs/reftable: fix leak when copying reflog fails
ci: add jobs to test with the reftable backend
refs: introduce reftable backend
Build dependency around unit tests has been fixed.
* jk/unit-tests-buildfix:
t/Makefile: say the default target upfront
t/Makefile: get UNIT_TESTS list from C sources
Makefile: remove UNIT_TEST_BIN directory with "make clean"
Makefile: use mkdir_p_parent_template for UNIT_TEST_BIN
The priority queue test has been migrated to the unit testing
framework.
* cp/unit-test-prio-queue:
tests: move t0009-prio-queue.sh to the new unit testing framework
Due to scalability issues, Shawn Pearce has originally proposed a new
"reftable" format more than six years ago [1]. Initially, this new
format was implemented in JGit with promising results. Around two years
ago, we have then added the "reftable" library to the Git codebase via
a4bbd13be3 (Merge branch 'hn/reftable', 2021-12-15). With this we have
landed all the low-level code to read and write reftables. Notably
missing though was the integration of this low-level code into the Git
code base in the form of a new ref backend that ties all of this
together.
This gap is now finally closed by introducing a new "reftable" backend
into the Git codebase. This new backend promises to bring some notable
improvements to Git repositories:
- It becomes possible to do truly atomic writes where either all refs
are committed to disk or none are. This was not possible with the
"files" backend because ref updates were split across multiple loose
files.
- The disk space required to store many refs is reduced, both compared
to loose refs and packed-refs. This is enabled both by the reftable
format being a binary format, which is more compact, and by prefix
compression.
- We can ignore filesystem-specific behaviour as ref names are not
encoded via paths anymore. This means there is no need to handle
case sensitivity on Windows systems or Unicode precomposition on
macOS.
- There is no need to rewrite the complete refdb anymore every time a
ref is being deleted like it was the case for packed-refs. This
means that ref deletions are now constant time instead of scaling
linearly with the number of refs.
- We can ignore file/directory conflicts so that it becomes possible
to store both "refs/heads/foo" and "refs/heads/foo/bar".
- Due to this property we can retain reflogs for deleted refs. We have
previously been deleting reflogs together with their refs to avoid
file/directory conflicts, which is not necessary anymore.
- We can properly enumerate all refs. With the "files" backend it is
not easily possible to distinguish between refs and non-refs because
they may live side by side in the gitdir.
Not all of these improvements are realized with the current "reftable"
backend implementation. At this point, the new backend is supposed to be
a drop-in replacement for the "files" backend that is used by basically
all Git repositories nowadays. It strives for 1:1 compatibility, which
means that a user can expect the same behaviour regardless of whether
they use the "reftable" backend or the "files" backend for most of the
part.
Most notably, this means we artificially limit the capabilities of the
"reftable" backend to match the limits of the "files" backend. It is not
possible to create refs that would end up with file/directory conflicts,
we do not retain reflogs, we perform stricter-than-necessary checks.
This is done intentionally due to two main reasons:
- It makes it significantly easier to land the "reftable" backend as
tests behave the same. It would be tough to argue for each and every
single test that doesn't pass with the "reftable" backend.
- It ensures compatibility between repositories that use the "files"
backend and repositories that use the "reftable" backend. Like this,
hosters can migrate their repositories to use the "reftable" backend
without causing issues for clients that use the "files" backend in
their clones.
It is expected that these artificial limitations may eventually go away
in the long term.
Performance-wise things very much depend on the actual workload. The
following benchmarks compare the "files" and "reftable" backends in the
current version:
- Creating N refs in separate transactions shows that the "files"
backend is ~50% faster. This is not surprising given that creating a
ref only requires us to create a single loose ref. The "reftable"
backend will also perform auto compaction on updates. In real-world
workloads we would likely also want to perform pack loose refs,
which would likely change the picture.
Benchmark 1: update-ref: create refs sequentially (refformat = files, refcount = 1)
Time (mean ± σ): 2.1 ms ± 0.3 ms [User: 0.6 ms, System: 1.7 ms]
Range (min … max): 1.8 ms … 4.3 ms 133 runs
Benchmark 2: update-ref: create refs sequentially (refformat = reftable, refcount = 1)
Time (mean ± σ): 2.7 ms ± 0.1 ms [User: 0.6 ms, System: 2.2 ms]
Range (min … max): 2.4 ms … 2.9 ms 132 runs
Benchmark 3: update-ref: create refs sequentially (refformat = files, refcount = 1000)
Time (mean ± σ): 1.975 s ± 0.006 s [User: 0.437 s, System: 1.535 s]
Range (min … max): 1.969 s … 1.980 s 3 runs
Benchmark 4: update-ref: create refs sequentially (refformat = reftable, refcount = 1000)
Time (mean ± σ): 2.611 s ± 0.013 s [User: 0.782 s, System: 1.825 s]
Range (min … max): 2.597 s … 2.622 s 3 runs
Benchmark 5: update-ref: create refs sequentially (refformat = files, refcount = 100000)
Time (mean ± σ): 198.442 s ± 0.241 s [User: 43.051 s, System: 155.250 s]
Range (min … max): 198.189 s … 198.670 s 3 runs
Benchmark 6: update-ref: create refs sequentially (refformat = reftable, refcount = 100000)
Time (mean ± σ): 294.509 s ± 4.269 s [User: 104.046 s, System: 190.326 s]
Range (min … max): 290.223 s … 298.761 s 3 runs
- Creating N refs in a single transaction shows that the "files"
backend is significantly slower once we start to write many refs.
The "reftable" backend only needs to update two files, whereas the
"files" backend needs to write one file per ref.
Benchmark 1: update-ref: create many refs (refformat = files, refcount = 1)
Time (mean ± σ): 1.9 ms ± 0.1 ms [User: 0.4 ms, System: 1.4 ms]
Range (min … max): 1.8 ms … 2.6 ms 151 runs
Benchmark 2: update-ref: create many refs (refformat = reftable, refcount = 1)
Time (mean ± σ): 2.5 ms ± 0.1 ms [User: 0.7 ms, System: 1.7 ms]
Range (min … max): 2.4 ms … 3.4 ms 148 runs
Benchmark 3: update-ref: create many refs (refformat = files, refcount = 1000)
Time (mean ± σ): 152.5 ms ± 5.2 ms [User: 19.1 ms, System: 133.1 ms]
Range (min … max): 148.5 ms … 167.8 ms 15 runs
Benchmark 4: update-ref: create many refs (refformat = reftable, refcount = 1000)
Time (mean ± σ): 58.0 ms ± 2.5 ms [User: 28.4 ms, System: 29.4 ms]
Range (min … max): 56.3 ms … 72.9 ms 40 runs
Benchmark 5: update-ref: create many refs (refformat = files, refcount = 1000000)
Time (mean ± σ): 152.752 s ± 0.710 s [User: 20.315 s, System: 131.310 s]
Range (min … max): 152.165 s … 153.542 s 3 runs
Benchmark 6: update-ref: create many refs (refformat = reftable, refcount = 1000000)
Time (mean ± σ): 51.912 s ± 0.127 s [User: 26.483 s, System: 25.424 s]
Range (min … max): 51.769 s … 52.012 s 3 runs
- Deleting a ref in a fully-packed repository shows that the "files"
backend scales with the number of refs. The "reftable" backend has
constant-time deletions.
Benchmark 1: update-ref: delete ref (refformat = files, refcount = 1)
Time (mean ± σ): 1.7 ms ± 0.1 ms [User: 0.4 ms, System: 1.2 ms]
Range (min … max): 1.6 ms … 2.1 ms 316 runs
Benchmark 2: update-ref: delete ref (refformat = reftable, refcount = 1)
Time (mean ± σ): 1.8 ms ± 0.1 ms [User: 0.4 ms, System: 1.3 ms]
Range (min … max): 1.7 ms … 2.1 ms 294 runs
Benchmark 3: update-ref: delete ref (refformat = files, refcount = 1000)
Time (mean ± σ): 2.0 ms ± 0.1 ms [User: 0.5 ms, System: 1.4 ms]
Range (min … max): 1.9 ms … 2.5 ms 287 runs
Benchmark 4: update-ref: delete ref (refformat = reftable, refcount = 1000)
Time (mean ± σ): 1.9 ms ± 0.1 ms [User: 0.5 ms, System: 1.3 ms]
Range (min … max): 1.8 ms … 2.1 ms 217 runs
Benchmark 5: update-ref: delete ref (refformat = files, refcount = 1000000)
Time (mean ± σ): 229.8 ms ± 7.9 ms [User: 182.6 ms, System: 46.8 ms]
Range (min … max): 224.6 ms … 245.2 ms 6 runs
Benchmark 6: update-ref: delete ref (refformat = reftable, refcount = 1000000)
Time (mean ± σ): 2.0 ms ± 0.0 ms [User: 0.6 ms, System: 1.3 ms]
Range (min … max): 2.0 ms … 2.1 ms 3 runs
- Listing all refs shows no significant advantage for either of the
backends. The "files" backend is a bit faster, but not by a
significant margin. When repositories are not packed the "reftable"
backend outperforms the "files" backend because the "reftable"
backend performs auto-compaction.
Benchmark 1: show-ref: print all refs (refformat = files, refcount = 1, packed = true)
Time (mean ± σ): 1.6 ms ± 0.1 ms [User: 0.4 ms, System: 1.1 ms]
Range (min … max): 1.5 ms … 2.0 ms 1729 runs
Benchmark 2: show-ref: print all refs (refformat = reftable, refcount = 1, packed = true)
Time (mean ± σ): 1.6 ms ± 0.1 ms [User: 0.4 ms, System: 1.1 ms]
Range (min … max): 1.5 ms … 1.8 ms 1816 runs
Benchmark 3: show-ref: print all refs (refformat = files, refcount = 1000, packed = true)
Time (mean ± σ): 4.3 ms ± 0.1 ms [User: 0.9 ms, System: 3.3 ms]
Range (min … max): 4.1 ms … 4.6 ms 645 runs
Benchmark 4: show-ref: print all refs (refformat = reftable, refcount = 1000, packed = true)
Time (mean ± σ): 4.5 ms ± 0.2 ms [User: 1.0 ms, System: 3.3 ms]
Range (min … max): 4.2 ms … 5.9 ms 643 runs
Benchmark 5: show-ref: print all refs (refformat = files, refcount = 1000000, packed = true)
Time (mean ± σ): 2.537 s ± 0.034 s [User: 0.488 s, System: 2.048 s]
Range (min … max): 2.511 s … 2.627 s 10 runs
Benchmark 6: show-ref: print all refs (refformat = reftable, refcount = 1000000, packed = true)
Time (mean ± σ): 2.712 s ± 0.017 s [User: 0.653 s, System: 2.059 s]
Range (min … max): 2.692 s … 2.752 s 10 runs
Benchmark 7: show-ref: print all refs (refformat = files, refcount = 1, packed = false)
Time (mean ± σ): 1.6 ms ± 0.1 ms [User: 0.4 ms, System: 1.1 ms]
Range (min … max): 1.5 ms … 1.9 ms 1834 runs
Benchmark 8: show-ref: print all refs (refformat = reftable, refcount = 1, packed = false)
Time (mean ± σ): 1.6 ms ± 0.1 ms [User: 0.4 ms, System: 1.1 ms]
Range (min … max): 1.4 ms … 2.0 ms 1840 runs
Benchmark 9: show-ref: print all refs (refformat = files, refcount = 1000, packed = false)
Time (mean ± σ): 13.8 ms ± 0.2 ms [User: 2.8 ms, System: 10.8 ms]
Range (min … max): 13.3 ms … 14.5 ms 208 runs
Benchmark 10: show-ref: print all refs (refformat = reftable, refcount = 1000, packed = false)
Time (mean ± σ): 4.5 ms ± 0.2 ms [User: 1.2 ms, System: 3.3 ms]
Range (min … max): 4.3 ms … 6.2 ms 624 runs
Benchmark 11: show-ref: print all refs (refformat = files, refcount = 1000000, packed = false)
Time (mean ± σ): 12.127 s ± 0.129 s [User: 2.675 s, System: 9.451 s]
Range (min … max): 11.965 s … 12.370 s 10 runs
Benchmark 12: show-ref: print all refs (refformat = reftable, refcount = 1000000, packed = false)
Time (mean ± σ): 2.799 s ± 0.022 s [User: 0.735 s, System: 2.063 s]
Range (min … max): 2.769 s … 2.836 s 10 runs
- Printing a single ref shows no real difference between the "files"
and "reftable" backends.
Benchmark 1: show-ref: print single ref (refformat = files, refcount = 1)
Time (mean ± σ): 1.5 ms ± 0.1 ms [User: 0.4 ms, System: 1.0 ms]
Range (min … max): 1.4 ms … 1.8 ms 1779 runs
Benchmark 2: show-ref: print single ref (refformat = reftable, refcount = 1)
Time (mean ± σ): 1.6 ms ± 0.1 ms [User: 0.4 ms, System: 1.1 ms]
Range (min … max): 1.4 ms … 2.5 ms 1753 runs
Benchmark 3: show-ref: print single ref (refformat = files, refcount = 1000)
Time (mean ± σ): 1.5 ms ± 0.1 ms [User: 0.3 ms, System: 1.1 ms]
Range (min … max): 1.4 ms … 1.9 ms 1840 runs
Benchmark 4: show-ref: print single ref (refformat = reftable, refcount = 1000)
Time (mean ± σ): 1.6 ms ± 0.1 ms [User: 0.4 ms, System: 1.1 ms]
Range (min … max): 1.5 ms … 2.0 ms 1831 runs
Benchmark 5: show-ref: print single ref (refformat = files, refcount = 1000000)
Time (mean ± σ): 1.6 ms ± 0.1 ms [User: 0.4 ms, System: 1.1 ms]
Range (min … max): 1.5 ms … 2.1 ms 1848 runs
Benchmark 6: show-ref: print single ref (refformat = reftable, refcount = 1000000)
Time (mean ± σ): 1.6 ms ± 0.1 ms [User: 0.4 ms, System: 1.1 ms]
Range (min … max): 1.5 ms … 2.1 ms 1762 runs
So overall, performance depends on the usecases. Except for many
sequential writes the "reftable" backend is roughly on par or
significantly faster than the "files" backend though. Given that the
"files" backend has received 18 years of optimizations by now this can
be seen as a win. Furthermore, we can expect that the "reftable" backend
will grow faster over time when attention turns more towards
optimizations.
The complete test suite passes, except for those tests explicitly marked
to require the REFFILES prerequisite. Some tests in t0610 are marked as
failing because they depend on still-in-flight bug fixes. Tests can be
run with the new backend by setting the GIT_TEST_DEFAULT_REF_FORMAT
environment variable to "reftable".
There is a single known conceptual incompatibility with the dumb HTTP
transport. As "info/refs" SHOULD NOT contain the HEAD reference, and
because the "HEAD" file is not valid anymore, it is impossible for the
remote client to figure out the default branch without changing the
protocol. This shortcoming needs to be handled in a subsequent patch
series.
As the reftable library has already been introduced a while ago, this
commit message will not go into the details of how exactly the on-disk
format works. Please refer to our preexisting technical documentation at
Documentation/technical/reftable for this.
[1]: https://public-inbox.org/git/CAJo=hJtyof=HRy=2sLP0ng0uZ4=S-DpZ5dR1aF+VHVETKG20OQ@mail.gmail.com/
Original-idea-by: Shawn Pearce <spearce@spearce.org>
Based-on-patch-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The Makefile often had to say "-L$(path) -R$(path)" that repeats
the path to the same library directory for link time and runtime.
A Makefile template is used to reduce such repetition.
* jc/make-libpath-template:
Makefile: simplify output of the libpath_template
Makefile: reduce repetitive library paths
* jk/unit-tests-buildfix:
t/Makefile: say the default target upfront
t/Makefile: get UNIT_TESTS list from C sources
Makefile: remove UNIT_TEST_BIN directory with "make clean"
Makefile: use mkdir_p_parent_template for UNIT_TEST_BIN
When we take a library package we depend on (e.g., LIBPCRE) from a
directory other than the default location of the system, we add the
same directory twice on the linker command like, like so:
EXTLIBS += -L$(LIBPCREDIR)/$(lib) $(CC_LD_DYNPATH)$(LIBPCREDIR)/$(lib)
Introduce a template "libpath_template" that takes the path to the
directory, which can be used like so:
EXTLIBS += $(call libpath_template,$(LIBPCREDIR)/$(lib))
and expand it into the "-L$(DIR) $(CC_LD_DYNPATH)$(DIR)" form.
Hopefully we can reduce the chance of typoes this way.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We remove $(UNIT_TEST_PROGS), but that leaves the automatically
generated "bin" dir they reside in. And once we start cleaning that,
there is no point in removing the individual programs, as they'll by
wiped out by the recurse "rm".
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We build the UNIT_TEST_BIN directory (t/unit-tests/bin) on the fly with
"mkdir -p". And so the recipe for UNIT_TEST_PROGS, which put their
output in that directory, depend on UNIT_TEST_BIN to make sure it's
there.
But using a normal dependency leads to weird outcomes, because the
timestamp of the directory is important. For example, try this:
$ make
[...builds everything...]
[now re-build one unit test]
$ touch t/unit-tests/t-ctype.c
$ make
SUBDIR templates
CC t/unit-tests/t-ctype.o
LINK t/unit-tests/bin/t-ctype
So far so good. Now running make again should build nothing. But it
doesn't!
$ make
SUBDIR templates
LINK t/unit-tests/bin/t-basic
LINK t/unit-tests/bin/t-mem-pool
LINK t/unit-tests/bin/t-strbuf
Er, what? Let's rebuild again:
$ make
SUBDIR templates
LINK t/unit-tests/bin/t-ctype
Weird. And now we ping-pong back and forth forever:
$ make
SUBDIR templates
LINK t/unit-tests/bin/t-basic
LINK t/unit-tests/bin/t-mem-pool
LINK t/unit-tests/bin/t-strbuf
$ make
SUBDIR templates
LINK t/unit-tests/bin/t-ctype
What happens is that writing t/unit-tests/bin/t-ctype updates the mtime
of the directory t/unit-tests/bin. And then on the next invocation of
make, all of those other tests are now older and so get rebuilt. And
back and forth forever.
We can fix this by making the directory as part of the build recipe for
the programs, using the template from 0b6d0bc924 (Makefiles: add and use
wildcard "mkdir -p" template, 2022-03-03).
Helped-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
