Incrementally updating multi-pack index files.
* tb/incremental-midx-part-2:
midx: implement writing incremental MIDX bitmaps
pack-bitmap.c: use `ewah_or_iterator` for type bitmap iterators
pack-bitmap.c: keep track of each layer's type bitmaps
ewah: implement `struct ewah_or_iterator`
pack-bitmap.c: apply pseudo-merge commits with incremental MIDXs
pack-bitmap.c: compute disk-usage with incremental MIDXs
pack-bitmap.c: teach `rev-list --test-bitmap` about incremental MIDXs
pack-bitmap.c: support bitmap pack-reuse with incremental MIDXs
pack-bitmap.c: teach `show_objects_for_type()` about incremental MIDXs
pack-bitmap.c: teach `bitmap_for_commit()` about incremental MIDXs
pack-bitmap.c: open and store incremental bitmap layers
pack-revindex: prepare for incremental MIDX bitmaps
Documentation: describe incremental MIDX bitmaps
Documentation: remove a "future work" item from the MIDX docs
Make the code in reftable library less reliant on the service
routines it used to borrow from Git proper, to make it easier to
use by external users of the library.
* ps/reftable-sans-compat-util:
Makefile: skip reftable library for Coccinelle
reftable: decouple from Git codebase by pulling in "compat/posix.h"
git-compat-util.h: split out POSIX-emulating bits
compat/mingw: split out POSIX-related bits
reftable/basics: introduce `REFTABLE_UNUSED` annotation
reftable/basics: stop using `SWAP()` macro
reftable/stack: stop using `sleep_millisec()`
reftable/system: introduce `reftable_rand()`
reftable/reader: stop using `ARRAY_SIZE()` macro
reftable/basics: provide wrappers for big endian conversion
reftable/basics: stop using `st_mult()` in array allocators
reftable: stop using `BUG()` in trivial cases
reftable/record: don't `BUG()` in `reftable_record_cmp()`
reftable/record: stop using `BUG()` in `reftable_record_init()`
reftable/record: stop using `COPY_ARRAY()`
reftable/blocksource: stop using `xmmap()`
reftable/stack: stop using `write_in_full()`
reftable/stack: stop using `read_in_full()`
TCP keepalive behaviour on http transports can now be configured by
calling cURL library.
* tb/http-curl-keepalive:
http.c: allow custom TCP keepalive behavior via config
http.c: inline `set_curl_keepalive()`
http.c: introduce `set_long_from_env()` for convenience
http.c: remove unnecessary casts to long
Give more meaningful error return values from block writer layer of
the reftable ref-API backend.
* ms/reftable-block-writer-errors:
reftable: adapt write_object_record() to propagate block_writer_add() errors
reftable: adapt writer_add_record() to propagate block_writer_add() errors
reftable: propagate specific error codes in block_writer_add()
Ensure what we write in assert() does not have side effects,
and introduce ASSERT() macro to mark those that cannot be
mechanically checked for lack of side effects.
* en/assert-wo-side-effects:
treewide: replace assert() with ASSERT() in special cases
ci: add build checking for side-effects in assert() calls
git-compat-util: introduce ASSERT() macro
When updating multiple references through stdin, Git's update-ref
command normally aborts the entire transaction if any single update
fails. This atomic behavior prevents partial updates. Introduce a new
batch update system, where the updates the performed together similar
but individual updates are allowed to fail.
Add a new `--batch-updates` flag that allows the transaction to continue
even when individual reference updates fail. This flag can only be used
in `--stdin` mode and builds upon the batch update support added to the
refs subsystem in the previous commits. When enabled, failed updates are
reported in the following format:
rejected SP (<old-oid> | <old-target>) SP (<new-oid> | <new-target>) SP <rejection-reason> LF
Update the documentation to reflect this change and also tests to cover
different scenarios where an update could be rejected.
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Acked-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `refs_verify_refnames_available()` is used to batch check refnames
for F/D conflicts. While this is the more performant alternative than
its individual version, it does not provide rejection capabilities on a
single update level. For batched updates, this would mean a rejection of
the entire transaction whenever one reference has a F/D conflict.
Modify the function to call `ref_transaction_maybe_set_rejected()` to
check if a single update can be rejected. Since this function is only
internally used within 'refs/' and we want to pass in a `struct
ref_transaction *` as a variable. We also move and mark
`refs_verify_refnames_available()` to 'refs-internal.h' to be an
internal function.
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Acked-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Git supports making reference updates with or without transactions.
Updates with transactions are generally better optimized. But
transactions are all or nothing. This means, if a user wants to batch
updates to take advantage of the optimizations without the hard
requirement that all updates must succeed, there is no way currently to
do so. Particularly with the reftable backend where batching multiple
reference updates is more efficient than performing them sequentially.
Introduce batched update support with a new flag,
'REF_TRANSACTION_ALLOW_FAILURE'. Batched updates while different from
transactions, use the transaction infrastructure under the hood. When
enabled, this flag allows individual reference updates that would
typically cause the entire transaction to fail due to non-system-related
errors to be marked as rejected while permitting other updates to
proceed. System errors referred by 'REF_TRANSACTION_ERROR_GENERIC'
continue to result in the entire transaction failing. This approach
enhances flexibility while preserving transactional integrity where
necessary.
The implementation introduces several key components:
- Add 'rejection_err' field to struct `ref_update` to track failed
updates with failure reason.
- Add a new struct `ref_transaction_rejections` and a field within
`ref_transaction` to this struct to allow quick iteration over
rejected updates.
- Modify reference backends (files, packed, reftable) to handle
partial transactions by using `ref_transaction_set_rejected()`
instead of failing the entire transaction when
`REF_TRANSACTION_ALLOW_FAILURE` is set.
- Add `ref_transaction_for_each_rejected_update()` to let callers
examine which updates were rejected and why.
This foundational change enables batched update support throughout the
reference subsystem. A following commit will expose this capability to
users by adding a `--batch-updates` flag to 'git-update-ref(1)',
providing both a user-facing feature and a testable implementation.
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Acked-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Replace preprocessor-defined transaction errors with a strongly-typed
enum `ref_transaction_error`. This change:
- Improves type safety and function signature clarity.
- Makes error handling more explicit and discoverable.
- Maintains existing error cases, while adding new error cases for
common scenarios.
This refactoring paves the way for more comprehensive error handling
which we will utilize in the upcoming commits to add batch reference
update support.
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Acked-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Extract the core logic for preparing individual reference updates from
`reftable_be_transaction_prepare()` into `prepare_single_update()`. This
dedicated function now handles all validation and preparation steps for
each reference update in the transaction, including object ID
verification, HEAD reference handling, and symref processing.
The refactoring consolidates all reference update validation into a
single logical block, which improves code maintainability and
readability. More importantly, this restructuring lays the groundwork
for implementing batched reference update support in the reftable
backend, which will be introduced in a followup commit.
No functional changes are included in this commit - it is purely a code
reorganization to support future enhancements.
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Acked-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Within the files reference backend's transaction's 'finish' phase, a
verification step is currently performed wherein the refnames list is
sorted and examined for multiple updates targeting the same refname.
It has been observed that this verification is redundant, as an
identical check is already executed during the transaction's 'prepare'
stage. Since the refnames list remains unmodified following the
'prepare' stage, this secondary verification can be safely eliminated.
The duplicate check has been removed accordingly, and the
`ref_update_reject_duplicates()` function has been marked as static, as
its usage is now confined to 'refs.c'.
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Acked-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Move the tracking of refnames in `affected_refnames` from individual
backends into the generic layer in 'refs.c'. This centralizes the
duplicate refname detection that was previously handled separately by
each backend.
Make some changes to accommodate this move:
- Add a `string_list` field `refnames` to `ref_transaction` to contain
all the references in a transaction. This field is updated whenever
a new update is added via `ref_transaction_add_update`, so manual
additions in reference backends are dropped.
- Modify the backends to use this field internally as needed. The
backends need to check if an update for refname already exists when
splitting symrefs or adding an update for 'HEAD'.
- In the reftable backend, within `reftable_be_transaction_prepare()`,
move the `string_list_has_string()` check above
`ref_transaction_add_update()`. Since `ref_transaction_add_update()`
automatically adds the refname to `transaction->refnames`,
performing the check after will always return true, so we perform
the check before adding the update.
This helps reduce duplication of functionality between the backends and
makes it easier to make changes in a more centralized manner.
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Acked-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In `split_symref_update()`, there were two checks for duplicate
refnames:
- At the start, `string_list_has_string()` ensures the refname is not
already in `affected_refnames`, preventing duplicates from being
added.
- After adding the refname, another check verifies whether the newly
inserted item has a `util` value.
The second check is unnecessary because the first one guarantees that
`string_list_insert()` will never encounter a preexisting entry.
The `item->util` field is assigned to validate that a rename doesn't
already exist in the list. The validation is done after the first check.
As this check is removed, clean up the validation and the assignment of
this field in `split_head_update()` and `files_transaction_prepare()`.
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Acked-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
By default, git-maintenance(1) uses the "gc" task to ensure that the
repository is well-maintained. This can be changed, for example by
either explicitly configuring which tasks should be enabled or by using
the "incremental" maintenance strategy. If so, git-maintenance(1) does
not know to expire reflog entries, which is a subtask that git-gc(1)
knows to perform for the user. Consequently, the reflog will grow
indefinitely unless the user manually trims it.
Introduce a new "reflog-expire" task that plugs this gap:
- When running the task directly, then we simply execute `git reflog
expire --all`, which is the same as git-gc(1).
- When running git-maintenance(1) with the `--auto` flag, then we only
run the task in case the "HEAD" reflog has at least N reflog entries
that would be discarded. By default, N is set to 100, but this can
be configured via "maintenance.reflog-expire.auto". When a negative
integer has been provided we always expire entries, zero causes us
to never expire entries, and a positive value specifies how many
entries need to exist before we consider pruning the entries.
Note that the condition for the `--auto` flags is merely a heuristic and
optimized for being fast. This is because `git maintenance run --auto`
will be executed quite regularly, so scanning through all reflogs would
likely be too expensive in many repositories.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We're about to introduce a new task for git-maintenance(1) that knows to
expire reflog entries. The logic will be shared with git-gc(1), which
already knows how to do this.
Pull out the common logic into a separate function so that we can share
the implementation between both builtins.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Make functions that are required to manage `reflog_expire_options`
available elsewhere by moving them into "reflog.c" and exposing them in
the corresponding header. The functions will be used in a subsequent
commit.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
As described in the preceding commit, the per-reflog expiry dates are
stored in a global pair of variables. Refactor the code so that they are
contained in `struct reflog_expire_options` to make the structure useful
in other contexts.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When expiring reflog entries, it is possible to configure expiry dates
that depend on the name of the reflog. This requires us to store a
couple of different expiry dates:
- The default expiry date for reflog entries that aren't otherwise
specified.
- The per-reflog expiry date.
- The currently active set of expiry dates for a given reference.
While the last item is stored in `struct reflog_expire_options`, the
other items aren't, which makes it hard to reuse the structure in other
places.
Refactor the code so that the default expiry date is stored as part of
the structure. The per-reflog expiry dates will be adapted accordingly
in the subsequent commit.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We're about to expose `struct cmd_reflog_expire_cb` via "reflog.h" so
that we can also use this structure in "builtin/gc.c". Once we make it
accessible to a wider scope though it becomes awkwardly named, as it
isn't only useful in the context of a callback. Instead, the function is
containing all kinds of options relevant to whether or not a reflog
entry should be expired.
Rename the structure to `reflog_expire_options` to prepare for this.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Code captured errors but did not process them further.
This treated all failures the same without distinguishing SMTP status.
Add handle-smtp_error to extract SMTP status codes using a regex (as
defined in RFC 5321) and handle errors as follows:
- No error present:
- If a result is provided, return 1 to indicate success.
- Otherwise, return 0 to indicate failure.
- Error present with a captured three-digit status code:
- For 4yz (transient errors), return 1 and allow retries.
- For 5yz (permanent errors), return 0 to indicate failure.
- For any other recognized status code, return 1, treating it as
a transient error.
- Error present but no status code found:
- Return 1 as a transient error.
Signed-off-by: Zheng Yuting <05ZYT30@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Auth relied solely on return values without catching errors. This misjudges
non-credential errors as auth failure without error info.
Patch wraps the entire auth process in an eval {} block to catch
all exceptions, including non-credential errors. It adds a new $error var,
uses 'or do' to prevent flow break, and returns $result ? 1 : 0. And merges
if/else branches, integrates SASL and basic auth, with comments for
future status code handling.
Signed-off-by: Zheng Yuting <05ZYT30@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The 'git-blame(1)' command allows users to ignore specific revisions via
the '--ignore-rev <rev>' and '--ignore-revs-file <file>' flags. These
flags are often combined with the 'blame.markIgnoredLines' and
'blame.markUnblamableLines' config options. These config options prefix
ignored and unblamable lines with a '?' and '*', respectively.
However, this option was never extended to the porcelain mode of
'git-blame(1)'. Since the documentation does not indicate this
exclusion, it is a bug.
Fix this by printing 'ignored' and 'unblamable' respectively for the
options when using the porcelain modes.
Helped-by: Patrick Steinhardt <ps@pks.im>
Helped-by: Toon Claes <toon@iotcl.com>
Helped-by: Phillip Wood <phillip.wood123@gmail.com>
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We use Perl due to two different reasons in t5703:
- To filter advertised capabilities.
- To set up a CGI script with HTTPD.
Refactor the first category to use `test_grep` instead. Refactoring the
second category would be a bit more involved, so instead we add the
PERL_TEST_HELPERS prerequisite to those individual tests now.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `max_chain()` helper function is used to extract the maximum delta
chain of a packfile as printed by git-index-pack(1). The script uses
Perl to extract that data, but it can be trivially refactored to use
awk(1) instead.
Refactor the helper accordingly so that we can drop a couple of
PERL_TEST_HELPERS prerequisites.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The output generated by our trace2 mechanism contains several fields
that are dependent on the environment they're being run in, which makes
it somewhat harder to test it. As a countermeasure we scrub the output
and strip out any fields that contain such information.
The logic to do so is implemented in Perl, but it can be trivially
ported to instead use sed(1). Refactor the code accordingly so that we
can drop the PERL_TEST_HELPERS prerequisite.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `generate_random_characters()` helper function generates N
random characters in the range 'a-z' and writes them into a file. The
logic currently uses Perl, but it can be adapted rather easily by:
- Making `test-tool genrandom` generate an infinite stream.
- Using `tr -dc` to strip all characters which aren't in the range of
'a-z'.
- Using `test_copy_bytes()` to copy the first N bytes.
This allows us to drop the PERL_TEST_HELPERS prerequisite.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Our Apache HTTPD setup exposes an "one_time_perl" endpoint to access
repositories. If used, we execute the "apply-one-time-perl.sh" CGI
script that checks whether we have a "one-time-perl" script. If so, that
script gets executed so that it can munge what would be served. Once
done, the script gets removed so that it doesn't execute a second time.
As the name says, this functionality expects the user to pass a Perl
script. This isn't really necessary though: we can just as easily
implement the same thing with arbitrary scripts.
Refactor the code so that we instead expect an arbitrary script to
exist and rename the functionality to "one-time-script". Adapt callers
to use shell utilities instead of Perl so that we can drop the
PERL_TEST_HELPERS prerequisite.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `name_from_description()` test helper uses Perl to munge a given
description and convert it into a name. Refactor it to instead use a
combination of sed(1) and tr(1) so that we drop PERL_TEST_HELPERS
prerequisites in users of this library.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `sanitize_pgp()` test helper uses Perl to strip PGP signatures from
stdin. Refactor it to instead use sed(1) so that we drop the
PERL_TEST_HELPERS prerequisite in users of this library.
Note that we have to add PERL_TEST_HELPERS to a subset of tests in t6300
now that the test suite doesn't bail out early anymore in case the
prerequisite isn't set.
Helped-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We have a couple of tests that depend on Perl for textconv scripts.
Refactor these tests to instead be implemented via shell utilities so
that we can drop a couple of PERL_TEST_HELPERS prerequisites.
Note that the conversion in t4030 is not a one-to-one equivalent to the
previous textconv script. Before this change we used to essentially do a
hexdump via Perl. The obvious conversion here would be to use `test-tool
hexdump` like we do for the other tests. But this would lead to a ripple
effect where we would have to adapt a bunch of other tests with a bunch
of seemingly unrelated changes, which would be somewhat awkward.
Instead, we're going with the minimum viable change: the test files we
write contain "\001" and "\000", and the test's expectation is that
those get translated into proper ASCII characters. So instead of doing a
full hexdump, we simply use tr(1) to translate these specific bytes.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A bunch of tests rely on Perl to print data in various different ways.
These usages fall into the following categories:
- Print data conditionally by matching patterns. These usecases can be
converted to use awk(1) rather easily.
- Print data repeatedly. These usecases can typically be converted to
use a combination of `test-tool genzeros` and sed(1).
- Print data in reverse. These usecases can be converted to use
awk(1) or `sort -r`.
Refactor the tests accordingly so that we can drop a couple of
PERL_TEST_HELPERS prerequisites.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We have a bunch of tests that use Perl to perform substitution via the
"s/" operator. These usecases can be trivially replaced with sed(1) and
tr(1).
Refactor the tests accordingly so that we can drop a couple of
PERL_TEST_HELPERS prerequisites.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We have a bunch of tests that use Perl to perform character
transliteration via the "y/" or "tr/" operator. These usecases can be
trivially replaced with tr(1).
Refactor the tests accordingly so that we can drop a couple of
PERL_TEST_HELPERS prerequisites.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The Makefile for our tests has a couple of targets that depend on Perl.
Adapt those targets to only run conditionally in case Perl is available
on the system so that it becomes possible to run the test suite without
Perl.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The Perl interpreter used to be a strict dependency for running our test
suite. This requirement is explicit in the Meson build system, where we
require Perl to be present unless tests have been disabled.
With the preceding commits we have loosened this restriction so that it
is now possible to run tests when Perl is unavailable. Loosen the above
requirement accordingly.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A couple of our tests depend on the PERL prerequisite even though it
isn't needed. These tests fall into one of the following classes:
- The underlying logic used to be implemented in Perl but isn't
anymore. Here we can simply drop the dependency altogether.
- The test logic used to depend on Perl but doesn't anymore. Again, we
can simply drop the dependency.
- The test logic still relies on a Perl interpreter. These tests
should use the newly introduced PERL_TEST_HELPERS prerequisite.
Adapt test cases accordingly.
Note that in t1006 we have to introduce another new prerequisite
depending on whether or not the IPC::Open2 module is available. Funny
enough, when starting to use `test_lazy_prereq` to do so we also get a
conflict of variables with the "script" variable that contains the Perl
logic because `test_run_lazy_prereq_` also sets that variable. We thus
rename the variable in t1006 to "perl_script".
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In the early days of Git, Perl was used quite prominently throughout the
project. This has changed significantly as almost all of the executables
we ship nowadays have eventually been rewritten in C. Only a handful of
subsystems remain that require Perl:
- gitweb, a read-only web interface.
- A couple of scripts that allow importing repositories from GNU Arch,
CVS and Subversion.
- git-send-email(1), which can be used to send mails.
- git-request-pull(1), which is used to request somebody to pull from
a URL by sending an email.
- git-filter-branch(1), which uses Perl with the `--state-branch`
option. This command is typically recommended against nowadays in
favor of git-filter-repo(1).
- Our Perl bindings for Git.
- The netrc Git credential helper.
None of these subsystems can really be considered to be part of the
"core" of Git, and an installation without them is fully functional.
It is more likely than not that an end user wouldn't even notice that
any features are missing if those tools weren't installed. But while
Perl nowadays very much is an optional dependency of Git, there is a
significant limitation when Perl isn't available: developers cannot run
our test suite.
Preceding commits have started to lift this restriction by removing the
strict dependency on Perl in many central parts of the test library. But
there are still many tests that rely on small Perl helpers to do various
different things.
Introduce a new PERL_TEST_HELPERS prerequisite that guards all tests
that require Perl. This prerequisite is explicitly different than the
preexisting PERL prerequisite:
- PERL records whether or not features depending on the Perl
interpreter are built.
- PERL_TEST_HELPERS records whether or not a Perl interpreter is
available for our tests.
By having these two separate prerequisites we can thus distinguish
between tests that inherently depend on Perl because the underlying
feature does, and those tests that depend on Perl because the test
itself is using Perl.
Adapt all tests to set the PERL_TEST_HELPERS prerequisite as needed.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `test_readlink()` helper function reads a symbolic link and returns
the path it is pointing to. It is thus equivalent to the readlink(1)
utility, which isn't available on all supported platforms. As such, it
is implemented using Perl so that we can use it even on platforms where
the shell utility isn't available.
While using readlink(1) is not an option, what we can do is to implement
the logic ourselves in our test-tool. Do so, which allows a bunch of
tests to pass when Perl is not available.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `test_copy_bytes()` helper function copies up to N bytes from stdin
to stdout. This is implemented using Perl, but it can be trivially
adapted to instead use dd(1).
Refactor the helper accordingly, which allows a bunch of tests to pass
when Perl is not available.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We have a couple of helper functions that translate characters, e.g.
from LF to NUL or NUL to 'Q' and vice versa. These helpers use Perl
scripts, but they can be trivially adapted to instead use tr(1).
Note that one specialty here is the handling of NUL characters in tr(1),
which historically wasn't implemented correctly on all platforms. But
quoting tr(1p):
It was considered that automatically stripping NUL characters from
the input was not correct functionality. However, the removal of -n
in a later proposal does not remove the requirement that tr
correctly process NUL characters in its input stream.
So when tr(1) is implemented following the POSIX standard then it is
expected to handle the transliteration of NUL just fine.
Refactor the helpers accordingly, which allows a bunch of tests to pass
when Perl is not available.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Before executing tests we first sanitize the environment. Part of the
sanitization is to unset a couple of environment variables that we know
will change the behaviour of Git. This is done with a small Perl script,
which has the consequence that having a Perl interpreter available is a
strict requirement for running our unit tests.
The logic itself isn't particularly involved: we simply unset every
environment variable whose key starts with 'GIT_', but then explicitly
allow a subset of these.
Refactor the logic to instead use sed(1) so that it becomes possible to
execute our tests without Perl.
Based-on-patch-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Our chainlint script verifies that test files have proper '&&' chains.
This script is written in Perl and executed for every test file before
executing the test logic itself.
In subsequent commits we're about to refactor our test suite so that
Perl becomes an optional dependency, only. And while it is already
possible to disable this linter, developers that don't have Perl
available at all would always have to disable the linter manually, which
is rather cumbersome.
Disable the chain linter automatically in case PERL_PATH isn't set to
make this a bit less annoying. Bail out with an error in case the
developer has asked explicitly for the chain linter.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
While it is now possible to filter objects by type, this mechanism is
for now mostly a convenience. Most importantly, we still have to iterate
through the whole packfile to find all objects of a specific type. This
can be prohibitively expensive depending on the size of the packfiles.
It isn't really possible to do better than this when only considering a
packfile itself, as the order of objects is not fixed. But when we have
a packfile with a corresponding bitmap, either because the packfile
itself has one or because the multi-pack index has a bitmap for it, then
we can use these bitmaps to improve the runtime.
While bitmaps are typically used to compute reachability of objects,
they also contain one bitmap per object type that encodes which object
has what type. So instead of reading through the whole packfile(s), we
can use the bitmaps and iterate through the type-specific bitmap.
Typically, only a subset of packfiles will have a bitmap. But this isn't
really much of a problem: we can use bitmaps when available, and then
use the non-bitmap walk for every packfile that isn't covered by one.
Overall, this leads to quite a significant speedup depending on how many
objects of a certain type exist. The following benchmarks have been
executed in the Chromium repository, which has a 50GB packfile with
almost 25 million objects. As expected, there isn't really much of a
change in performance without an object filter:
Benchmark 1: cat-file with no-filter (revision = HEAD~)
Time (mean ± σ): 89.675 s ± 4.527 s [User: 40.807 s, System: 10.782 s]
Range (min … max): 83.052 s … 96.084 s 10 runs
Benchmark 2: cat-file with no-filter (revision = HEAD)
Time (mean ± σ): 88.991 s ± 2.488 s [User: 42.278 s, System: 10.305 s]
Range (min … max): 82.843 s … 91.271 s 10 runs
Summary
cat-file with no-filter (revision = HEAD) ran
1.01 ± 0.06 times faster than cat-file with no-filter (revision = HEAD~)
We still have to scan through all objects as we yield all of them, so
using the bitmap in this case doesn't really buy us anything. What is
noticeable in this benchmark is that we're I/O-bound, not CPU-bound, as
can be seen from the user/system runtimes, which combined are way lower
than the overall benchmarked runtime.
But when we do use a filter we can see a significant improvement:
Benchmark 1: cat-file with filter=object:type=commit (revision = HEAD~)
Time (mean ± σ): 86.444 s ± 4.081 s [User: 36.830 s, System: 11.312 s]
Range (min … max): 80.305 s … 93.104 s 10 runs
Benchmark 2: cat-file with filter=object:type=commit (revision = HEAD)
Time (mean ± σ): 2.089 s ± 0.015 s [User: 1.872 s, System: 0.207 s]
Range (min … max): 2.073 s … 2.119 s 10 runs
Summary
cat-file with filter=object:type=commit (revision = HEAD) ran
41.38 ± 1.98 times faster than cat-file with filter=object:type=commit (revision = HEAD~)
This is because we don't have to scan through all packfiles anymore, but
can instead directly look up relevant objects.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Pull out a common function that allows us to iterate over all objects in
a repository. Right now the logic is trivial and would only require two
function calls, making this refactoring a bit pointless. But in the next
commit we will iterate on this logic to make use of bitmaps, so this is
about to become a bit more complex.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce a function that allows us to verify whether a pack is
bitmapped or not. This functionality will be used in a subsequent
commit.
Helped-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce a function that allows the caller to iterate over all
bitmapped objects that match a given filter. This mechanism will be used
in a subsequent commit to optimize object filters in git-cat-file(1).
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Junio C Hamano