In preparation for a subsequent commit that migrates code using
add_submodule_odb() to repo_submodule_init(), teach
repo_submodule_init() to support submodules with unabsorbed gitdirs.
(See the documentation for "git submodule absorbgitdirs" for more
information about absorbed and unabsorbed gitdirs.)
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Record the repository whenever an OID grep source is created, and teach
the worker threads to explicitly provide the repository when accessing
objects.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Reviewed-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Currently, struct repository objects corresponding to submodules are
allocated on the stack in grep_submodule(). This currently works because
they will not be used once grep_submodule() exits, but a subsequent
patch will require these structs to be accessible for longer (perhaps
even in another thread). Allocate them on the heap and clear them only
at the very end.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Reviewed-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Replace an existing parse_object_or_die() call (which implicitly works
on the_repository) with a function call that allows a repository to be
passed in. There is no such direct equivalent to parse_object_or_die(),
but we only need the type of the object, so replace with
oid_object_info().
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Reviewed-by: Emily Shaffer <emilyshaffer@google.com>
Reviewed-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
grep_source_init() can create "struct grep_source" objects and,
depending on the value of the type passed, some void-pointer parameters have
different meanings. Because one of these types (GREP_SOURCE_OID) will
require an additional parameter in a subsequent patch, take the
opportunity to increase clarity and type safety by replacing this
function with individual functions for each type.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Reviewed-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In the parent commit, Git was taught to add submodule ODBs as alternates
lazily, but grep does not use this because it computes the path to add
directly, not going through add_submodule_odb(). Add an equivalent to
add_submodule_odb() that takes the exact ODB path and teach grep to use
it.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Reviewed-by: Emily Shaffer <emilyshaffer@google.com>
Reviewed-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Remove the dir_init() function and replace it with a DIR_INIT
macro. In many cases in the codebase we need to initialize things with
a function for good reasons, e.g. needing to call another function on
initialization. The "dir_init()" function was not one such case, and
could trivially be replaced with a more idiomatic macro initialization
pattern.
The only place where we made use of its use of memset() was in
dir_clear() itself, which resets the contents of an an existing struct
pointer. Let's use the new "memcpy() a 'blank' struct on the stack"
idiom to do that reset.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
SHA-256 transition.
* bc/hash-transition-interop-part-1:
hex: print objects using the hash algorithm member
hex: default to the_hash_algo on zero algorithm value
builtin/pack-objects: avoid using struct object_id for pack hash
commit-graph: don't store file hashes as struct object_id
builtin/show-index: set the algorithm for object IDs
hash: provide per-algorithm null OIDs
hash: set, copy, and use algo field in struct object_id
builtin/pack-redundant: avoid casting buffers to struct object_id
Use the final_oid_fn to finalize hashing of object IDs
hash: add a function to finalize object IDs
http-push: set algorithm when reading object ID
Always use oidread to read into struct object_id
hash: add an algo member to struct object_id
Builds on top of the sparse-index infrastructure to mark operations
that are not ready to mark with the sparse index, causing them to
fall back on fully-populated index that they always have worked with.
* ds/sparse-index-protections: (47 commits)
name-hash: use expand_to_path()
sparse-index: expand_to_path()
name-hash: don't add directories to name_hash
revision: ensure full index
resolve-undo: ensure full index
read-cache: ensure full index
pathspec: ensure full index
merge-recursive: ensure full index
entry: ensure full index
dir: ensure full index
update-index: ensure full index
stash: ensure full index
rm: ensure full index
merge-index: ensure full index
ls-files: ensure full index
grep: ensure full index
fsck: ensure full index
difftool: ensure full index
commit: ensure full index
checkout: ensure full index
...
Up until recently, object IDs did not have an algorithm member, only a
hash. Consequently, it was possible to share one null (all-zeros)
object ID among all hash algorithms. Now that we're going to be
handling objects from multiple hash algorithms, it's important to make
sure that all object IDs have a correct algorithm field.
Introduce a per-algorithm null OID, and add it to struct hash_algo.
Introduce a wrapper function as well, and use it everywhere we used to
use the null_oid constant.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Before iterating over all cache entries, ensure that a sparse index is
expanded to a full one so we do not miss blobs to scan. Later, this can
integrate more carefully with sparse indexes with proper testing.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Updates to memory allocation code around the use of pcre2 library.
* ab/grep-pcre2-allocfix:
grep/pcre2: move definitions of pcre2_{malloc,free}
grep/pcre2: move back to thread-only PCREv2 structures
grep/pcre2: actually make pcre2 use custom allocator
grep/pcre2: use pcre2_maketables_free() function
grep/pcre2: use compile-time PCREv2 version test
grep/pcre2: add GREP_PCRE2_DEBUG_MALLOC debug mode
grep/pcre2: prepare to add debugging to pcre2_malloc()
grep/pcre2: correct reference to grep_init() in comment
grep/pcre2: drop needless assignment to NULL
grep/pcre2: drop needless assignment + assert() on opt->pcre2
Add and apply a semantic patch for converting code that open-codes
CALLOC_ARRAY to use it instead. It shortens the code and infers the
element size automatically.
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git grep" has been tweaked to be limited to the sparse checkout
paths.
* mt/grep-sparse-checkout:
grep: honor sparse-checkout on working tree searches
"git grep --untracked" is meant to be "let's ALSO find in these
files on the filesystem" when looking for matches in the working
tree files, and does not make any sense if the primary search is
done against the index, or the tree objects. The "--cached" and
"--untracked" options have been marked as mutually incompatible.
* mt/grep-cached-untracked:
grep: error out if --untracked is used with --cached
Change the setup of the "pcre2_general_context" to happen per-thread
in compile_pcre2_pattern() instead of in grep_init().
This change brings it in line with how the rest of the pcre2_* members
in the grep_pat structure are set up.
As noted in the preceding commit the approach 513f2b0bbd (grep: make
PCRE2 aware of custom allocator, 2019-10-16) took to allocate the
pcre2_general_context seems to have been initially based on a
misunderstanding of how PCREv2 memory allocation works.
The approach of creating a global context in grep_init() is just added
complexity for almost zero gain. On my system it's 24 bytes saved
per-thread. For comparison PCREv2 will then go on to allocate at least
a kilobyte for its own thread-local state.
As noted in 6d423dd542 (grep: don't redundantly compile throwaway
patterns under threading, 2017-05-25) the grep code is intentionally
not trying to micro-optimize allocations by e.g. sharing some PCREv2
structures globally, while making others thread-local.
So let's remove this special case and make all of them thread-local
again for simplicity. With this change we could move the
pcre2_{malloc,free} functions around to live closer to their current
use. I'm not doing that here to keep this change small, that cleanup
will be done in a follow-up commit.
See also the discussion in 94da9193a6 (grep: add support for PCRE v2,
2017-06-01) about thread safety, and Johannes's comments[1] to the
effect that we should be doing what this patch is doing.
1. https://lore.kernel.org/git/nycvar.QRO.7.76.6.1908052120302.46@tvgsbejvaqbjf.bet/
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
On a sparse checked out repository, `git grep` (without --cached) ends
up searching the cache when an entry matches the search pathspec and has
the SKIP_WORKTREE bit set. This is confusing both because the sparse
paths are not expected to be in a working tree search (as they are not
checked out), and because the output mixes working tree and cache
results without distinguishing them. (Note that grep also resorts to the
cache on working tree searches that include --assume-unchanged paths.
But the whole point in that case is to assume that the contents of the
index entry and the file are the same. This does not apply to the case
of sparse paths, where the file isn't even expected to be present.)
Fix that by teaching grep to honor the sparse-checkout rules for working
tree searches. If the user wants to grep paths outside the current
sparse-checkout definition, they may either update the sparsity rules to
materialize the files, or use --cached to search all blobs registered in
the index.
Note: it might also be interesting to add a configuration option that
allow users to search paths that are present despite having the
SKIP_WORKTREE bit set, and/or to restrict searches in the index and past
revisions too. These ideas are left as future improvements to avoid
conflicting with other sparse-checkout topics currently in flight.
Suggested-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The options --untracked and --cached are not compatible, but if they are
used together, grep just silently ignores --cached and searches the
working tree. Error out, instead, to avoid any potential confusion.
Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Remove the hidden "grep --debug" and "log --grep-debug" options added
in 17bf35a3c7 (grep: teach --debug option to dump the parse tree,
2012-09-13).
At the time these options seem to have been intended to go along with
a documentation discussion and to help the author of relevant tests to
perform ad-hoc debugging on them[1].
Reasons to want this gone:
1. They were never documented, and the only (rather trivial) use of
them in our own codebase for testing is something I removed back
in e01b4dab01 (grep: change non-ASCII -i test to stop using
--debug, 2017-05-20).
2. Googling around doesn't show any in-the-wild uses I could dig up,
and on the Git ML the only mentions after the original discussion
seem to have been when they came up in unrelated diff contexts, or
that test commit of mine.
3. An exception to that is c581e4a749 (grep: under --debug, show
whether PCRE JIT is enabled, 2019-08-18) where we added the
ability to dump out when PCREv2 has the JIT in effect.
The combination of that and my earlier b65abcafc7 (grep: use PCRE
v2 for optimized fixed-string search, 2019-07-01) means Git prints
this out in its most common in-the-wild configuration:
$ git log --grep-debug --grep=foo --grep=bar --grep=baz --all-match
pcre2_jit_on=1
pcre2_jit_on=1
pcre2_jit_on=1
[all-match]
(or
pattern_body<body>foo
(or
pattern_body<body>bar
pattern_body<body>baz
)
)
$ git grep --debug \( -e foo --and -e bar \) --or -e baz
pcre2_jit_on=1
pcre2_jit_on=1
pcre2_jit_on=1
(or
(and
patternfoo
patternbar
)
patternbaz
)
I.e. for each pattern we're considering for the and/or/--all-match
etc. debugging we'll now diligently spew out another identical line
saying whether the PCREv2 JIT is on or not.
I think that nobody's complained about that rather glaringly obviously
bad output says something about how much this is used, i.e. it's
not.
The need for this debugging aid for the composed grep/log patterns
seems to have passed, and the desire to dump the JIT config seems to
have been another one-off around the time we had JIT-related issues on
the PCREv2 codepath. That the original author of this debugging
facility seemingly hasn't noticed the bad output since then[2] is
probably some indicator.
1. https://lore.kernel.org/git/cover.1347615361.git.git@drmicha.warpmail.net/
2. https://lore.kernel.org/git/xmqqk1b8x0ac.fsf@gitster-ct.c.googlers.com/
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In 15fabd1bbd ("builtin/grep.c: make configuration callback more
reusable", 2012-10-09), we learned to fill a `static struct grep_opt
grep_defaults` which we can use as a blueprint for other such structs.
At the time, we didn't consider designated initializers to be widely
useable, but these days, we do. (See, e.g., cbc0f81d96 ("strbuf: use
designated initializers in STRBUF_INIT", 2017-07-10).)
Use designated initializers to let the compiler set up the struct and so
that we don't need to remember to call `init_grep_defaults()`.
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
`init_grep_defaults()` fills a `static struct grep_opt grep_defaults`.
This struct is then used by `grep_init()` as a blueprint for other such
structs. Notably, `grep_init()` takes a `struct repo *` and assigns it
into the target struct.
As a result, it is unnecessary for us to take a `struct repo *` in
`init_grep_defaults()` as well. We assign it into the default struct and
never look at it again. And in light of how we return early if we have
already set up the default struct, it's not just unnecessary, but is
also a bit confusing: If we are called twice and with different repos,
is it a bug or a feature that we ignore the second repo?
Drop the repo parameter for `init_grep_defaults()`.
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
deref_tag() can return NULL. Exit gracefully in that case instead
of blindly dereferencing the return value.
.name shouldn't ever be NULL, but grep_object() handles that case
explicitly, so let's be defensive here as well and show the broken
object's ID if it happens to lack a name after all.
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The quote_path() function computes a path (relative to its base
directory) and c-quotes the result if necessary. Teach it to take a
flags parameter to allow its behaviour to be enriched later.
No behaviour change intended.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There is no quote_path_absolute() or anything that causes confusion,
and one of the two large consumers already rename the long name
locally with a preprocessor macro.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The dir structure seemed to have a number of leaks and problems around
it. First I noticed that parent_hashmap and recursive_hashmap were
being leaked (though Peff noticed and submitted fixes before me). Then
I noticed in the previous commit that clear_directory() was only taking
responsibility for a subset of fields within dir_struct, despite the
fact that entries[] and ignored[] we allocated internally to dir.c.
That, of course, resulted in many callers either leaking or haphazardly
trying to free these arrays and their contents.
Digging further, I found that despite the pretty clear documentation
near the top of dir.h that folks were supposed to call clear_directory()
when the user no longer needed the dir_struct, there were four callers
that didn't bother doing that at all. However, two of them clearly
thought about leaks since they had an UNLEAK(dir) directive, which to me
suggests that the method to free the data was too unclear. I suspect
the non-obviousness of the API and its holes led folks to avoid it,
which then snowballed into further problems with the entries[],
ignored[], parent_hashmap, and recursive_hashmap problems.
Rename clear_directory() to dir_clear() to be more in line with other
data structures in git, and introduce a dir_init() to handle the
suggested memsetting of dir_struct to all zeroes. I hope that a name
like "dir_clear()" is more clear, and that the presence of dir_init()
will provide a hint to those looking at the code that they need to look
for either a dir_clear() or a dir_free() and lead them to find
dir_clear().
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The argv_array API is useful for not just managing argv but any
"vector" (NULL-terminated array) of strings, and has seen adoption
to a certain degree. It has been renamed to "strvec" to reduce the
barrier to adoption.
* jk/strvec:
strvec: rename struct fields
strvec: drop argv_array compatibility layer
strvec: update documention to avoid argv_array
strvec: fix indentation in renamed calls
strvec: convert remaining callers away from argv_array name
strvec: convert more callers away from argv_array name
strvec: convert builtin/ callers away from argv_array name
quote: rename sq_dequote_to_argv_array to mention strvec
strvec: rename files from argv-array to strvec
argv-array: rename to strvec
argv-array: use size_t for count and alloc
parse_object_or_die() is passed an object ID and a name to show if the
object cannot be parsed. If the name is NULL then it shows the
hexadecimal object ID. Use that feature instead of preparing and
passing the hexadecimal representation to the function proactively.
That's shorter and a bit more efficient.
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We eventually want to drop the argv_array name and just use strvec
consistently. There's no particular reason we have to do it all at once,
or care about interactions between converted and unconverted bits.
Because of our preprocessor compat layer, the names are interchangeable
to the compiler (so even a definition and declaration using different
names is OK).
This patch converts all of the files in builtin/ to keep the diff to a
manageable size.
The conversion was done purely mechanically with:
git ls-files '*.c' '*.h' |
xargs perl -i -pe '
s/ARGV_ARRAY/STRVEC/g;
s/argv_array/strvec/g;
'
and then selectively staging files with "git add builtin/". We'll deal
with any indentation/style fallouts separately.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The directory traversal code had redundant recursive calls which
made its performance characteristics exponential with respect to
the depth of the tree, which was corrected.
* en/fill-directory-exponential:
completion: fix 'git add' on paths under an untracked directory
Fix error-prone fill_directory() API; make it only return matches
dir: replace double pathspec matching with single in treat_directory()
dir: include DIR_KEEP_UNTRACKED_CONTENTS handling in treat_directory()
dir: replace exponential algorithm with a linear one
dir: refactor treat_directory to clarify control flow
dir: fix confusion based on variable tense
dir: fix broken comment
dir: consolidate treat_path() and treat_one_path()
dir: fix simple typo in comment
t3000: add more testcases testing a variety of ls-files issues
t7063: more thorough status checking
In the codebase, there are many options which use OPTION_CALLBACK in a
plain ol' struct definition. However, we have the OPT_CALLBACK and
OPT_CALLBACK_F macros which are meant to abstract these plain struct
definitions away. These macros are useful as they semantically signal to
developers that these are just normal callback option with nothing fancy
happening.
Replace plain struct definitions of OPTION_CALLBACK with OPT_CALLBACK or
OPT_CALLBACK_F where applicable. The heavy lifting was done using the
following (disgusting) shell script:
#!/bin/sh
do_replacement () {
tr '\n' '\r' |
sed -e 's/{\s*OPTION_CALLBACK,\s*\([^,]*\),\([^,]*\),\([^,]*\),\([^,]*\),\([^,]*\),\s*0,\(\s*[^[:space:]}]*\)\s*}/OPT_CALLBACK(\1,\2,\3,\4,\5,\6)/g' |
sed -e 's/{\s*OPTION_CALLBACK,\s*\([^,]*\),\([^,]*\),\([^,]*\),\([^,]*\),\([^,]*\),\([^,]*\),\(\s*[^[:space:]}]*\)\s*}/OPT_CALLBACK_F(\1,\2,\3,\4,\5,\6,\7)/g' |
tr '\r' '\n'
}
for f in $(git ls-files \*.c)
do
do_replacement <"$f" >"$f.tmp"
mv "$f.tmp" "$f"
done
The result was manually inspected and then reformatted to match the
style of the surrounding code. Finally, using
`git grep OPTION_CALLBACK \*.c`, leftover results which were not handled
by the script were manually transformed.
Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
grep does not follow the conventions used by other Git commands when
printing paths that contain unusual characters (as double-quotes or
newlines). Commands such as ls-files, commit, status and diff will:
- Quote and escape unusual pathnames, by default.
- Print names verbatim and unquoted when "-z" is used.
But grep *never* quotes/escapes absolute paths with unusual chars and
*always* quotes/escapes relative ones, even with "-z". Besides being
inconsistent in its own output, the deviation from other Git commands
can be confusing. So let's make it follow the two rules above and add
some tests for this new behavior. Note that, making grep quote/escape
all unusual paths by default, also make it fully compliant with the
core.quotePath configuration, which is currently ignored for absolute
paths.
Reported-by: Greg Hurrell <greg@hurrell.net>
Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Traditionally, the expected calling convention for the dir.c API was:
fill_directory(&dir, ..., pathspec)
foreach entry in dir->entries:
if (dir_path_match(entry, pathspec))
process_or_display(entry)
This may have made sense once upon a time, because the fill_directory() call
could use cheap checks to avoid doing full pathspec matching, and an external
caller may have wanted to do other post-processing of the results anyway.
However:
* this structure makes it easy for users of the API to get it wrong
* this structure actually makes it harder to understand
fill_directory() and the functions it uses internally. It has
tripped me up several times while trying to fix bugs and
restructure things.
* relying on post-filtering was already found to produce wrong
results; pathspec matching had to be added internally for multiple
cases in order to get the right results (see commits 404ebceda0
(dir: also check directories for matching pathspecs, 2019-09-17)
and 89a1f4aaf7 (dir: if our pathspec might match files under a
dir, recurse into it, 2019-09-17))
* it's bad for performance: fill_directory() already has to do lots
of checks and knows the subset of cases where it still needs to do
more checks. Forcing external callers to do full pathspec
matching means they must re-check _every_ path.
So, add the pathspec matching within the fill_directory() internals, and
remove it from external callers.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Traditionally, we avoided threaded grep while searching in objects
(as opposed to files in the working tree) as accesses to the object
layer is not thread-safe. This limitation is getting lifted.
* mt/threaded-grep-in-object-store:
grep: use no. of cores as the default no. of threads
grep: move driver pre-load out of critical section
grep: re-enable threads in non-worktree case
grep: protect packed_git [re-]initialization
grep: allow submodule functions to run in parallel
submodule-config: add skip_if_read option to repo_read_gitmodules()
grep: replace grep_read_mutex by internal obj read lock
object-store: allow threaded access to object reading
replace-object: make replace operations thread-safe
grep: fix racy calls in grep_objects()
grep: fix race conditions at grep_submodule()
grep: fix race conditions on userdiff calls
Since grep learned to recurse into submodules in 0281e487fd
(grep: optionally recurse into submodules, 2016-12-16),
using --recurse-submodules along with --no-index makes Git
die().
This is unfortunate because if submodule.recurse is set in a user's
~/.gitconfig, invoking `git grep --no-index` either inside or outside
a Git repository results in
fatal: option not supported with --recurse-submodules
Let's allow using these options together, so that setting submodule.recurse
globally does not prevent using `git grep --no-index`.
Using `--recurse-submodules` should not have any effect if `--no-index`
is used inside a repository, as Git will recurse into the checked out
submodule directories just like into regular directories.
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In builtin/grep.c:add_work() we pre-load the userdiff drivers before
adding the grep_source in the todo list. This operation is currently
being performed after acquiring the grep_mutex, but as it's already
thread-safe, we don't need to protect it here. So let's move it out of
the critical section which should avoid thread contention and improve
performance.
Running[1] `git grep --threads=8 abcd[02] HEAD` on chromium's
repository[2], I got the following mean times for 30 executions after 2
warmups:
Original | 6.2886s
-------------------------|-----------
Out of critical section | 5.7852s
[1]: Tests performed on an i7-7700HQ with 16GB of RAM and SSD, running
Manjaro Linux.
[2]: chromium’s repo at commit 03ae96f (“Add filters testing at DSF=2”,
04-06-2019), after a 'git gc' execution.
Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
They were disabled at 53b8d93 ("grep: disable threading in non-worktree
case", 12-12-2011), due to observable performance drops (to the point
that using a single thread would be faster than multiple threads). But
now that zlib inflation can be performed in parallel we can regain the
speedup, so let's re-enable threads in non-worktree grep.
Grepping 'abcd[02]' ("Regex 1") and '(static|extern) (int|double) \*'
("Regex 2") at chromium's repository[1] I got:
Threads | Regex 1 | Regex 2
---------|------------|-----------
1 | 17.2920s | 20.9624s
2 | 9.6512s | 11.3184s
4 | 6.7723s | 7.6268s
8** | 6.2886s | 6.9843s
These are all means of 30 executions after 2 warmup runs. All tests were
executed on an i7-7700HQ (quad-core w/ hyper-threading), 16GB of RAM and
SSD, running Manjaro Linux. But to make sure the optimization also
performs well on HDD, the tests were repeated on another machine with an
i5-4210U (dual-core w/ hyper-threading), 8GB of RAM and HDD (SATA III,
5400 rpm), also running Manjaro Linux:
Threads | Regex 1 | Regex 2
---------|------------|-----------
1 | 18.4035s | 22.5368s
2 | 12.5063s | 14.6409s
4** | 10.9136s | 12.7106s
** Note that in these cases we relied on hyper-threading, and that's
probably why we don't see a big difference in time.
Unfortunately, multithreaded git-grep might be slow in the non-worktree
case when --textconv is used and there're too many text conversions.
Probably the reason for this is that the object read lock is used to
protect fill_textconv() and therefore there is a mutual exclusion
between textconv execution and object reading. Because both are
time-consuming operations, not being able to perform them in parallel
can cause performance drops. To inform the users about this (and other
threading details), let's also add a "NOTES ON THREADS" section to
Documentation/git-grep.txt.
[1]: chromium’s repo at commit 03ae96f (“Add filters testing at DSF=2”,
04-06-2019), after a 'git gc' execution.
Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Some fields in struct raw_object_store are lazy initialized by the
thread-unsafe packfile.c:prepare_packed_git(). Although this function is
present in the call stack of git-grep threads, all paths to it are
currently protected by obj_read_lock() (and the main thread usually
indirectly calls it before firing the worker threads, anyway). However,
it's possible that future modifications add new unprotected paths to it,
introducing a race condition. Because errors derived from it wouldn't
happen often, it could be hard to detect. So to prevent future
headaches, let's force eager initialization of packed_git when setting
git-grep up. There'll be a small overhead in the cases where we didn't
really need to prepare packed_git during execution but this shouldn't be
very noticeable.
Also, packed_git may be re-initialized by
packfile.c:reprepare_packed_git(). Again, all paths to it in git-grep
are already protected by obj_read_lock() but it may suffer from the same
problem in the future. So let's also internally protect it with
obj_read_lock() (which is a recursive mutex).
Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Now that object reading operations are internally protected, the
submodule initialization functions at builtin/grep.c:grep_submodule()
are very close to being thread-safe. Let's take a look at each call and
remove from the critical section what we can, for better performance:
- submodule_from_path() and is_submodule_active() cannot be called in
parallel yet only because they call repo_read_gitmodules() which
contains, in its call stack, operations that would otherwise be in
race condition with object reading (for example parse_object() and
is_promisor_remote()). However, they only call repo_read_gitmodules()
if it wasn't read before. So let's pre-read it before firing the
threads and allow these two functions to safely be called in
parallel.
- repo_submodule_init() is already thread-safe, so remove it from the
critical section without other necessary changes.
- The repo_read_gitmodules(&subrepo) call at grep_submodule() is safe as
no other thread is performing object reading operations in the subrepo
yet. However, threads might be working in the superproject, and this
function calls add_to_alternates_memory() internally, which is racy
with object readings in the superproject. So it must be kept
protected for now. Let's add a "NEEDSWORK" to it, informing why it
cannot be removed from the critical section yet.
- Finally, add_to_alternates_memory() must be kept protected for the
same reason as the item above.
Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Currently, submodule-config.c doesn't have an externally accessible
function to read gitmodules only if it wasn't already read. But this
exact behavior is internally implemented by gitmodules_read_check(), to
perform a lazy load. Let's merge this function with
repo_read_gitmodules() adding a 'skip_if_read' which allows both
internal and external callers to access this functionality. This
simplifies a little the code. The added option will also be used in
the following patch.
Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
git-grep uses 'grep_read_mutex' to protect its calls to object reading
operations. But these have their own internal lock now, which ensures a
better performance (allowing parallel access to more regions). So, let's
remove the former and, instead, activate the latter with
enable_obj_read_lock().
Sections that are currently protected by 'grep_read_mutex' but are not
internally protected by the object reading lock should be surrounded by
obj_read_lock() and obj_read_unlock(). These guarantee mutual exclusion
with object reading operations, keeping the current behavior and
avoiding race conditions. Namely, these places are:
In grep.c:
- fill_textconv() at fill_textconv_grep().
- userdiff_get_textconv() at grep_source_1().
In builtin/grep.c:
- parse_object_or_die() and the submodule functions at
grep_submodule().
- deref_tag() and gitmodules_config_oid() at grep_objects().
If these functions become thread-safe, in the future, we might remove
the locking and probably get some speedup.
Note that some of the submodule functions will already be thread-safe
(or close to being thread-safe) with the internal object reading lock.
However, as some of them will require additional modifications to be
removed from the critical section, this will be done in its own patch.
Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
deref_tag() calls is_promisor_object() and parse_object(), both of which
perform lazy initializations and other thread-unsafe operations. If it
was only called by grep_objects() this wouldn't be a problem as the
latter is only executed by the main thread. However, deref_tag() is also
present in read_object_file()'s call stack. So calling deref_tag() in
grep_objects() without acquiring the grep_read_mutex may incur in a race
condition with object reading operations (such as the ones internally
performed by fill_textconv(), called at fill_textconv_grep()). The same
problem happens with the call to gitmodules_config_oid() which also has
parse_object() in its call stack. Fix that protecting both calls with
the said grep_read_mutex.
Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There're currently two function calls in builtin/grep.c:grep_submodule()
which might result in race conditions:
- submodule_from_path(): it has config_with_options() in its call stack
which, in turn, may have read_object_file() in its own. Therefore,
calling the first function without acquiring grep_read_mutex may end
up causing a race condition with other object read operations
performed by worker threads (for example, at the fill_textconv()
call in grep.c:fill_textconv_grep()).
- parse_object_or_die(): it falls into the same problem, having
repo_has_object_file(the_repository, ...) in its call stack. Besides
that, parse_object(), which is also called by parse_object_or_die(),
is thread-unsafe and also called by object reading functions.
It's unlikely to really fall into a data race with these operations as
the volume of calls to them is usually very low. But we better protect
ourselves against this possibility, anyway. So, to solve these issues,
move both of these function calls into the critical section of
grep_read_mutex.
Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Leakfix.
* cb/pcre2-chartables-leakfix:
grep: avoid leak of chartables in PCRE2
grep: make PCRE2 aware of custom allocator
grep: make PCRE1 aware of custom allocator
94da9193a6 (grep: add support for PCRE v2, 2017-06-01) didn't include
a way to override the system allocator, and so it is incompatible with
custom allocators (e.g. nedmalloc). This problem became obvious when we
tried to plug a memory leak by `free()`ing a data structure allocated by
PCRE2, triggering a segfault in Windows (where we use nedmalloc by
default).
PCRE2 requires the use of a general context to override the allocator
and therefore, there is a lot more code needed than in PCRE1, including
a couple of wrapper functions.
Extend the grep API with a "destructor" that could be called to cleanup
any objects that were created and used globally.
Update `builtin/grep.c` to use that new API, but any other future users
should make sure to have matching `grep_init()`/`grep_destroy()` calls
if they are using the pattern matching functionality.
Move some of the logic that was before done per thread (in the workers)
into an earlier phase to avoid degrading performance, but as the use of
PCRE2 with custom allocators is better understood it is expected more of
its functions will be instructed to use the custom allocator as well as
was done in the original code[1] this work was based on.
[1] https://public-inbox.org/git/3397e6797f872aedd18c6d795f4976e1c579514b.1565005867.git.gitgitgadget@gmail.com/
Reported-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Append the strbuf buffer only after detaching it. There is no practical
difference here, as the strbuf is not empty and no strbuf_ function is
called between storing the pointer to the still attached buffer and
calling strbuf_detach(), so that pointer is valid, but make sure to
follow the standard sequence anyway for consistency.
Signed-off-by: René Scharfe <l.s.r@web.de>
Acked-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git grep --recurse-submodules" that looks at the working tree
files looked at the contents in the index in submodules, instead of
files in the working tree.
* mt/grep-submodules-working-tree:
grep: fix worktree case in submodules
Running git-grep with --recurse-submodules results in a cached grep for
the submodules even when --cached is not used. This makes all
modifications in submodules' tracked files be always ignored when
grepping. Solve that making git-grep respect the cached option when
invoking grep_cache() inside grep_submodule(). Also, add tests to
ensure that the desired behavior is performed.
Reported-by: Daniel Zaoui <jackdanielz@eyomi.org>
Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jonathan Tan
Ævar Arnfjörð Bjarmason
Junio C Hamano
brian m. carlson
Derrick Stolee
René Scharfe
Matheus Tavares
Martin Ågren
Elijah Newren
Jeff King
Denton Liu
Philippe Blain
Carlo Marcelo Arenas Belón
Nguyễn Thái Ngọc Duy