Update "perl-compatible regular expression" support to enable JIT
and also allow linking with the newer PCRE v2 library.
* ab/pcre-v2:
grep: add support for PCRE v2
grep: un-break building with PCRE >= 8.32 without --enable-jit
grep: un-break building with PCRE < 8.20
grep: un-break building with PCRE < 8.32
grep: add support for the PCRE v1 JIT API
log: add -P as a synonym for --perl-regexp
grep: skip pthreads overhead when using one thread
grep: don't redundantly compile throwaway patterns under threading
The internal logic used in "git blame" has been libified to make it
easier to use by cgit.
* js/blame-lib: (29 commits)
blame: move entry prepend to libgit
blame: move scoreboard setup to libgit
blame: move scoreboard-related methods to libgit
blame: move fake-commit-related methods to libgit
blame: move origin-related methods to libgit
blame: move core structures to header
blame: create entry prepend function
blame: create scoreboard setup function
blame: create scoreboard init function
blame: rework methods that determine 'final' commit
blame: wrap blame_sort and compare_blame_final
blame: move progress updates to a scoreboard callback
blame: make sanity_check use a callback in scoreboard
blame: move no_whole_file_rename flag to scoreboard
blame: move xdl_opts flags to scoreboard
blame: move show_root flag to scoreboard
blame: move reverse flag to scoreboard
blame: move contents_from to scoreboard
blame: move copy/move thresholds to scoreboard
blame: move stat counters to scoreboard
...
The "collision detecting" SHA-1 implementation shipped with 2.13
was quite broken on some big-endian platforms and/or platforms that
do not like unaligned fetches. Update to the upstream code which
has already fixed these issues.
* ab/sha1dc-maint:
sha1dc: update from upstream
The internal implementation of "git grep" has seen some clean-up.
* ab/grep-preparatory-cleanup: (31 commits)
grep: assert that threading is enabled when calling grep_{lock,unlock}
grep: given --threads with NO_PTHREADS=YesPlease, warn
pack-objects: fix buggy warning about threads
pack-objects & index-pack: add test for --threads warning
test-lib: add a PTHREADS prerequisite
grep: move is_fixed() earlier to avoid forward declaration
grep: change internal *pcre* variable & function names to be *pcre1*
grep: change the internal PCRE macro names to be PCRE1
grep: factor test for \0 in grep patterns into a function
grep: remove redundant regflags assignments
grep: catch a missing enum in switch statement
perf: add a comparison test of log --grep regex engines with -F
perf: add a comparison test of log --grep regex engines
perf: add a comparison test of grep regex engines with -F
perf: add a comparison test of grep regex engines
perf: emit progress output when unpacking & building
perf: add a GIT_PERF_MAKE_COMMAND for when *_MAKE_OPTS won't do
grep: add tests to fix blind spots with \0 patterns
grep: prepare for testing binary regexes containing rx metacharacters
grep: add a test helper function for less verbose -f \0 tests
...
Add support for v2 of the PCRE API. This is a new major version of
PCRE that came out in early 2015[1].
The regular expression syntax is the same, but while the API is
similar, pretty much every function is either renamed or takes
different arguments. Thus using it via entirely new functions makes
sense, as opposed to trying to e.g. have one compile_pcre_pattern()
that would call either PCRE v1 or v2 functions.
Git can now be compiled with either USE_LIBPCRE1=YesPlease or
USE_LIBPCRE2=YesPlease, with USE_LIBPCRE=YesPlease currently being a
synonym for the former. Providing both is a compile-time error.
With earlier patches to enable JIT for PCRE v1 the performance of the
release versions of both libraries is almost exactly the same, with
PCRE v2 being around 1% slower.
However after I reported this to the pcre-dev mailing list[2] I got a
lot of help with the API use from Zoltán Herczeg, he subsequently
optimized some of the JIT functionality in v2 of the library.
Running the p7820-grep-engines.sh performance test against the latest
Subversion trunk of both, with both them and git compiled as -O3, and
the test run against linux.git, gives the following results. Just the
/perl/ tests shown:
$ GIT_PERF_REPEAT_COUNT=30 GIT_PERF_LARGE_REPO=~/g/linux GIT_PERF_MAKE_COMMAND='grep -q LIBPCRE2 Makefile && make -j8 USE_LIBPCRE2=YesPlease CC=~/perl5/installed/bin/gcc NO_R_TO_GCC_LINKER=YesPlease CFLAGS=-O3 LIBPCREDIR=/home/avar/g/pcre2/inst LDFLAGS=-Wl,-rpath,/home/avar/g/pcre2/inst/lib || make -j8 USE_LIBPCRE=YesPlease CC=~/perl5/installed/bin/gcc NO_R_TO_GCC_LINKER=YesPlease CFLAGS=-O3 LIBPCREDIR=/home/avar/g/pcre/inst LDFLAGS=-Wl,-rpath,/home/avar/g/pcre/inst/lib' ./run HEAD~5 HEAD~ HEAD p7820-grep-engines.sh
[...]
Test HEAD~5 HEAD~ HEAD
-----------------------------------------------------------------------------------------------------------------
7820.3: perl grep 'how.to' 0.31(1.10+0.48) 0.21(0.35+0.56) -32.3% 0.21(0.34+0.55) -32.3%
7820.7: perl grep '^how to' 0.56(2.70+0.40) 0.24(0.64+0.52) -57.1% 0.20(0.28+0.60) -64.3%
7820.11: perl grep '[how] to' 0.56(2.66+0.38) 0.29(0.95+0.45) -48.2% 0.23(0.45+0.54) -58.9%
7820.15: perl grep '(e.t[^ ]*|v.ry) rare' 1.02(5.77+0.42) 0.31(1.02+0.54) -69.6% 0.23(0.50+0.54) -77.5%
7820.19: perl grep 'm(ú|u)lt.b(æ|y)te' 0.38(1.57+0.42) 0.27(0.85+0.46) -28.9% 0.21(0.33+0.57) -44.7%
See commit ("perf: add a comparison test of grep regex engines",
2017-04-19) for details on the machine the above test run was executed
on.
Here HEAD~2 is git with PCRE v1 without JIT, HEAD~ is PCRE v1 with
JIT, and HEAD is PCRE v2 (also with JIT). See previous commits of mine
mentioning p7820-grep-engines.sh for more details on the test setup.
For ease of readability, a different run just of HEAD~ (PCRE v1 with
JIT v.s. PCRE v2), again with just the /perl/ tests shown:
[...]
Test HEAD~ HEAD
----------------------------------------------------------------------------------------
7820.3: perl grep 'how.to' 0.21(0.42+0.52) 0.21(0.31+0.58) +0.0%
7820.7: perl grep '^how to' 0.25(0.65+0.50) 0.20(0.31+0.57) -20.0%
7820.11: perl grep '[how] to' 0.30(0.90+0.50) 0.23(0.46+0.53) -23.3%
7820.15: perl grep '(e.t[^ ]*|v.ry) rare' 0.30(1.19+0.38) 0.23(0.51+0.51) -23.3%
7820.19: perl grep 'm(ú|u)lt.b(æ|y)te' 0.27(0.84+0.48) 0.21(0.34+0.57) -22.2%
I.e. the two are either neck-to-neck, but PCRE v2 usually pulls ahead,
when it does it's around 20% faster.
A brief note on thread safety: As noted in pcre2api(3) & pcre2jit(3)
the compiled pattern can be shared between threads, but not some of
the JIT context, however the grep threading support does all pattern &
JIT compilation in separate threads, so this code doesn't need to
concern itself with thread safety.
See commit 63e7e9d8b6 ("git-grep: Learn PCRE", 2011-05-09) for the
initial addition of PCRE v1. This change follows some of the same
patterns it did (and which were discussed on list at the time),
e.g. mocking up types with typedef instead of ifdef-ing them out when
USE_LIBPCRE2 isn't defined. This adds some trivial memory use to the
program, but makes the code look nicer.
1. https://lists.exim.org/lurker/message/20150105.162835.0666407a.en.html
2. https://lists.exim.org/lurker/thread/20170419.172322.833ee099.en.html
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Amend my change earlier in this series ("grep: add support for the
PCRE v1 JIT API", 2017-04-11) to un-break the build on PCRE v1
versions later than 8.31 compiled without --enable-jit.
As explained in that change and a later compatibility change in this
series ("grep: un-break building with PCRE < 8.32", 2017-05-10) the
pcre_jit_exec() function is a faster path to execute the JIT.
Unfortunately there's no compatibility stub for that function compiled
into the library if pcre_config(PCRE_CONFIG_JIT, &ret) would return 0,
and no macro that can be used to check for it, so the only portable
option to support builds without --enable-jit is via a new
NO_LIBPCRE1_JIT=UnfortunatelyYes Makefile option[1].
Another option would be to make the JIT opt-in via
USE_LIBPCRE1_JIT=YesPlease, after all it's not a default option of
PCRE v1.
I think it makes more sense to make it opt-out since even though it's
not a default option, most packagers of PCRE seem to turn it on by
default, with the notable exception of the MinGW package.
Make the MinGW platform work by default by changing the build defaults
to turn on NO_LIBPCRE1_JIT=UnfortunatelyYes. It is the only platform
that turns on USE_LIBPCRE=YesPlease by default, see commit
df5218b4c3 ("config.mak.uname: support MSys2", 2016-01-13) for that
change.
1. "How do I support pcre1 JIT on all
versions?" (https://lists.exim.org/lurker/thread/20170601.103148.10253788.en.html)
2. https://github.com/Alexpux/MINGW-packages/blob/master/mingw-w64-pcre/PKGBUILD
(referenced from "Re: PCRE v2 compile error, was Re: What's cooking
in git.git (May 2017, #01; Mon, 1)";
<alpine.DEB.2.20.1705021756530.3480@virtualbox>)
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Code from "conversion using external process" codepath has been
extracted to a separate sub-process.[ch] module.
* bp/sub-process-convert-filter:
convert: update subprocess_read_status() to not die on EOF
sub-process: move sub-process functions into separate files
convert: rename reusable sub-process functions
convert: update generic functions to only use generic data structures
convert: separate generic structures and variables from the filter specific ones
convert: split start_multi_file_filter() into two separate functions
pkt-line: annotate packet_writel with LAST_ARG_MUST_BE_NULL
convert: move packet_write_line() into pkt-line as packet_writel()
pkt-line: add packet_read_line_gently()
pkt-line: fix packet_read_line() to handle len < 0 errors
convert: remove erroneous tests for errno == EPIPE
Add a PTHREADS prerequisite which is false when git is compiled with
NO_PTHREADS=YesPlease.
There's lots of custom code that runs when threading isn't available,
but before this prerequisite there was no way to test it.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Change the internal USE_LIBPCRE define, & build options flag to use a
naming convention ending in PCRE1, without changing the long-standing
USE_LIBPCRE Makefile flag which enables this code.
This is for preparation for libpcre2 support where having things like
USE_LIBPCRE and USE_LIBPCRE2 in any more places than we absolutely
need to for backwards compatibility with old Makefile arguments would
be confusing.
In some ways it would be better to change everything that now uses
USE_LIBPCRE to use USE_LIBPCRE1, and to make specifying
USE_LIBPCRE (or --with-pcre) an error. This would impose a one-time
burden on packagers of git to s/USE_LIBPCRE/USE_LIBPCRE1/ in their
build scripts.
However I'd like to leave the door open to making
USE_LIBPCRE=YesPlease eventually mean USE_LIBPCRE2=YesPlease,
i.e. once PCRE v2 is ubiquitous enough that it makes sense to make it
the default.
This code and the USE_LIBPCRE Makefile argument was added in commit
63e7e9d8b6 ("git-grep: Learn PCRE", 2011-05-09). At the time there was
no indication that the PCRE project would release an entirely new &
incompatible API around 3 years later.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Update sha1dc from the latest version by the upstream
maintainer[1].
This version includes a commit of mine which allows for replacing the
local modifications done to the upstream files in git.git with macro
definitions to monkeypatch it in place.
It also brings in a change[2] upstream made for the breakage 2.13.0
introduced on SPARC and other platforms that forbid unaligned
access[3].
This means that the code customizations done since the initial import
in commit 28dc98e343 ("sha1dc: add collision-detecting sha1
implementation", 2017-03-16) can be done purely via Makefile
definitions and by including the content of our own sha1dc_git.[ch] in
sha1dc/sha1.c via a macro.
1. cc465543b3
2. 33a694a9ee
3. "Git 2.13.0 segfaults on Solaris SPARC due to DC_SHA1=YesPlease
being on by default"
(https://public-inbox.org/git/CACBZZX6nmKK8af0-UpjCKWV4R+hV-uk2xWXVA5U+_UQ3VXU03g@mail.gmail.com/)
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a git GIT_PERF_MAKE_COMMAND variable to compliment the existing
GIT_PERF_MAKE_OPTS facility. This allows specifying an arbitrary shell
command to execute instead of 'make'.
This is useful e.g. in cases where the name, semantics or defaults of
a Makefile flag have changed over time. It can even be used to change
the contents of the tree, useful for monkeypatching ancient versions
of git to get them to build.
This opens Pandora's box in some ways, it's now possible to
"jailbreak" the perf environment and e.g. modify the source tree via
this arbitrary instead of just issuing a custom "make" command, such a
command has to be re-entrant in the sense that subsequent perf runs
will re-use the possibly modified tree.
It would be pointless to try to mitigate or work around that caveat in
a tool purely aimed at Git developers, so this change makes no attempt
to do so.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Reword an outdated & inaccurate comment which suggests that only
git-grep can use PCRE.
This comment was added back when PCRE support was initially added in
commit 63e7e9d8b6 ("git-grep: Learn PCRE", 2011-05-09), and was true
at the time.
It hasn't been telling the full truth since git-log learned to use
PCRE with --grep in commit 727b6fc3ed ("log --grep: accept
--basic-regexp and --perl-regexp", 2012-10-03), and more importantly
is likely to get more inaccurate over time as more use is made of PCRE
in other areas.
Reword it to be more future-proof, and to more clearly explain that
this enables user-initiated runtime behavior.
Copy/pasting this so much in configure.ac is lame, these Makefile-like
flags aren't even used by autoconf, just the corresponding
--with[out]-* options. But copy/pasting the comments that make sense
for the Makefile to configure.ac where they make less sense is the
pattern everything else follows in that file. I'm not going to war
against that as part of this change, just following the existing
pattern.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Move the sub-proces functions into sub-process.h/c. Add documentation
for the new module in Documentation/technical/api-sub-process.txt
Signed-off-by: Ben Peart <benpeart@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The internals of the refs API around the cached refs has been
streamlined.
* mh/separate-ref-cache:
do_for_each_entry_in_dir(): delete function
files_pack_refs(): use reference iteration
commit_packed_refs(): use reference iteration
cache_ref_iterator_begin(): make function smarter
get_loose_ref_cache(): new function
get_loose_ref_dir(): function renamed from get_loose_refs()
do_for_each_entry_in_dir(): eliminate `offset` argument
refs: handle "refs/bisect/" in `loose_fill_ref_dir()`
ref-cache: use a callback function to fill the cache
refs: record the ref_store in ref_cache, not ref_dir
ref-cache: introduce a new type, ref_cache
refs: split `ref_cache` code into separate files
ref-cache: rename `remove_entry()` to `remove_entry_from_dir()`
ref-cache: rename `find_ref()` to `find_ref_entry()`
ref-cache: rename `add_ref()` to `add_ref_entry()`
refs_verify_refname_available(): use function in more places
refs_verify_refname_available(): implement once for all backends
refs_ref_iterator_begin(): new function
refs_read_raw_ref(): new function
get_ref_dir(): don't call read_loose_refs() for "refs/bisect"
"git checkout" that handles a lot of paths has been optimized by
reducing the number of unnecessary checks of paths in the
has_dir_name() function.
* jh/add-index-entry-optim:
read-cache: speed up has_dir_name (part 2)
read-cache: speed up has_dir_name (part 1)
read-cache: speed up add_index_entry during checkout
p0006-read-tree-checkout: perf test to time read-tree
read-cache: add strcmp_offset function
Hotfix for a topic that is already in 'master'.
* jh/memihash-opt:
p0004: make perf test executable
t3008: skip lazy-init test on a single-core box
test-online-cpus: helper to return cpu count
name-hash: fix buffer overrun
The "submodule" specific field in the ref_store structure is
replaced with a more generic "gitdir" that can later be used also
when dealing with ref_store that represents the set of refs visible
from the other worktrees.
* nd/files-backend-git-dir: (28 commits)
refs.h: add a note about sorting order of for_each_ref_*
t1406: new tests for submodule ref store
t1405: some basic tests on main ref store
t/helper: add test-ref-store to test ref-store functions
refs: delete pack_refs() in favor of refs_pack_refs()
files-backend: avoid ref api targeting main ref store
refs: new transaction related ref-store api
refs: add new ref-store api
refs: rename get_ref_store() to get_submodule_ref_store() and make it public
files-backend: replace submodule_allowed check in files_downcast()
refs: move submodule code out of files-backend.c
path.c: move some code out of strbuf_git_path_submodule()
refs.c: make get_main_ref_store() public and use it
refs.c: kill register_ref_store(), add register_submodule_ref_store()
refs.c: flatten get_ref_store() a bit
refs: rename lookup_ref_store() to lookup_submodule_ref_store()
refs.c: introduce get_main_ref_store()
files-backend: remove the use of git_path()
files-backend: add and use files_ref_path()
files-backend: add and use files_reflog_path()
...
Update the build dependency so that an update to /usr/bin/perl
etc. result in recomputation of perl.mak file.
* ab/regen-perl-mak-with-different-perl:
perl: regenerate perl.mak if perl -V changes
The `ref_cache` code is currently too tightly coupled to
`files-backend`, making the code harder to understand and making it
awkward for new code to use `ref_cache` (as we indeed have planned).
Start loosening that coupling by splitting `ref_cache` into a separate
module.
This commit moves code, adds declarations, and changes the visibility
of some functions, but doesn't change any code.
The modules are still too tightly coupled, but the situation will be
improved in subsequent commits.
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add strcmp_offset() function to also return the offset of the
first change.
Add unit test and helper to verify.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Created helper executable to print the value of online_cpus()
allowing multi-threaded tests to be skipped when appropriate.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Change the perl/perl.mak build process so that the file is regenerated
if the output of "perl -V" changes.
Before this change updating e.g. /usr/bin/perl to a new major version
would cause the next "make" command to fail, since perl.mak has
hardcoded paths to perl library paths retrieved from its first run.
Now the logic added in commit ee9be06770 ("perl: detect new files in
MakeMaker builds", 2012-07-27) is extended to regenerate
perl/perl.mak if there's any change to "perl -V".
This will in some cases redundantly trigger perl/perl.mak to be
re-made, e.g. if @INC is modified in ways the build process doesn't
care about through sitecustomize.pl, but the common case is that we
just do the right thing and re-generate perl/perl.mak when needed.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The "make coccicheck" target runs spatch against each source
file. But it does so in a for loop, so "make" never sees the
exit code of spatch. Worse, it redirects stderr to a log
file, so the user has no indication of any failure. And then
to top it all off, because we touched the patch file's
mtime, make will refuse to repeat the command because it
think the target is up-to-date.
So for example:
$ make coccicheck SPATCH=does-not-exist
SPATCH contrib/coccinelle/free.cocci
SPATCH contrib/coccinelle/qsort.cocci
SPATCH contrib/coccinelle/xstrdup_or_null.cocci
SPATCH contrib/coccinelle/swap.cocci
SPATCH contrib/coccinelle/strbuf.cocci
SPATCH contrib/coccinelle/object_id.cocci
SPATCH contrib/coccinelle/array.cocci
$ make coccicheck SPATCH=does-not-exist
make: Nothing to be done for 'coccicheck'.
With this patch, you get:
$ make coccicheck SPATCH=does-not-exist
SPATCH contrib/coccinelle/free.cocci
/bin/sh: 4: does-not-exist: not found
Makefile:2338: recipe for target 'contrib/coccinelle/free.cocci.patch' failed
make: *** [contrib/coccinelle/free.cocci.patch] Error 1
It also dumps the log on failure, so any errors from spatch
itself (like syntax errors in our .cocci files) will be seen
by the user.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The name-hash used for detecting paths that are different only in
cases (which matter on case insensitive filesystems) has been
optimized to take advantage of multi-threading when it makes sense.
* jh/memihash-opt:
name-hash: add test-lazy-init-name-hash to .gitignore
name-hash: add perf test for lazy_init_name_hash
name-hash: add test-lazy-init-name-hash
name-hash: perf improvement for lazy_init_name_hash
hashmap: document memihash_cont, hashmap_disallow_rehash api
hashmap: add disallow_rehash setting
hashmap: allow memihash computation to be continued
name-hash: specify initial size for istate.dir_hash table
The "detect attempt to create collisions" variant of SHA-1
implementation by Marc Stevens (CWI) and Dan Shumow (Microsoft)
has been integrated and made the default.
* jk/sha1dc:
Makefile: make DC_SHA1 the default
t0013: add a basic sha1 collision detection test
Makefile: add DC_SHA1 knob
sha1dc: disable safe_hash feature
sha1dc: adjust header includes for git
sha1dc: add collision-detecting sha1 implementation
Add t/helper/test-lazy-init-name-hash.c test code
to demonstrate performance times for lazy_init_name_hash()
using the original single-threaded and the new multi-threaded
code paths.
Includes a --dump option to dump the created hashmaps to
stdout. You can use this to run both code paths and
confirm that they generate the same hashmaps.
Includes a --analyze option to analyze performance of both
code paths over a range of index sizes to help you find a
lower bound for the LAZY_THREAD_COST in name-hash.c.
For example, passing "-a 4000" will set "istate.cache_nr"
to 4000 and then try the multi-threaded code -- probably
giving 2 threads with 2000 entries each. It will then
run both the single-threaded (1x4000) and the multi-threaded
(2x2000) and compare the times. It will then repeat the
test with 8000, 12000, and etc. so that you can see the
cross over.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Our source code has used the SHA1_HEADER cpp macro after "#include"
in the C code to switch among the SHA-1 implementations. Instead,
list the exact header file names and switch among implementations
using "#ifdef BLK_SHA1/#include "block-sha1/sha1.h"/.../#endif";
this helps some IDE tools.
* bc/sha1-header-selection-with-cpp-macros:
hash.h: move SHA-1 implementation selection into a header file
Picking two versions of Git and running tests to make sure the
older one and the newer one interoperate happily has now become
possible.
* jk/interop-test:
t/interop: add test of old clients against modern git-daemon
t: add an interoperability test harness
We used to use the SHA1 implementation from the OpenSSL library by
default. As we are trying to be careful against collision attacks
after the recent "shattered" announcement, switch the default to
encourage people to use DC_SHA1 implementation instead. Those who
want to use the implementation from OpenSSL can explicitly ask for
it by OPENSSL_SHA1=YesPlease when running "make".
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We don't actually have a Git-object collision, so the best
we can do is to run one of the shattered PDFs through
test-sha1. This should trigger the collision check and die.
In a sense this isn't really checking anything that the
upstream sha1collisiondetection project doesn't cover
already. But it at least makes sure that our build correctly
uses the library.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This knob lets you use the sha1dc implementation from:
https://github.com/cr-marcstevens/sha1collisiondetection
which can detect certain types of collision attacks (even
when we only see half of the colliding pair). So it
mitigates any attack which consists of getting the "good"
half of a collision into a trusted repository, and then
later replacing it with the "bad" half. The "good" half is
rejected by the victim's version of Git (and even if they
run an old version of Git, any sha1dc-enabled git will
complain loudly if it ever has to interact with the object).
The big downside is that it's slower than either the openssl
or block-sha1 implementations.
Here are some timings based off of linux.git:
- compute sha1 over whole packfile
sha1dc: 3.580s
blk-sha1: 2.046s (-43%)
openssl: 1.335s (-62%)
- rev-list --all --objects
sha1dc: 33.512s
blk-sha1: 33.514s (+0.0%)
openssl: 33.650s (+0.4%)
- git log --no-merges -10000 -p
sha1dc: 8.124s
blk-sha1: 7.986s (-1.6%)
openssl: 8.203s (+0.9%)
- index-pack --verify
sha1dc: 4m19s
blk-sha1: 2m57s (-32%)
openssl: 2m19s (-42%)
So overall the sha1 computation with collision detection is
about 1.75x slower than block-sha1, and 2.7x slower than
sha1. But of course most operations do more than just sha1.
Normal object access isn't really slowed at all (both the
+/- changes there are well within the run-to-run noise); any
changes are drowned out by the other work Git is doing.
The most-affected operation is `index-pack --verify`, which
is essentially just computing the sha1 on every object. This
is similar to the `index-pack` invocation that the receiver
of a push or fetch would perform. So clearly there's some
extra CPU load here.
There will also be some latency for the user, though keep in
mind that such an operation will generally be network bound
(this is about a 1.2GB packfile). Some of that extra CPU is
"free" in the sense that we use it while the pack is
streaming in anyway. But most of it comes during the
delta-resolution phase, after the whole pack has been
received. So we can imagine that for this (quite large)
push, the user might have to wait an extra 100 seconds over
openssl (which is what we use now). If we assume they can
push to us at 20Mbit/s, that's 480s for a 1.2GB pack, which
is only 20% slower.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Many developers use functionality in their editors that allows for quick
syntax checks, including warning about questionable constructs. This
functionality allows rapid development with fewer errors. However, such
functionality generally does not allow the specification of
project-specific defines or command-line options.
Since the SHA1_HEADER include is not defined in such a case,
developers see spurious errors when using these tools. Furthermore,
there are known implementations of "cc" whose '#include' is unhappy
with this construct.
Instead of using SHA1_HEADER, create a hash.h header and use #if
and #elif to select the desired header. Have the Makefile pass an
appropriate option to help the header select the right implementation to
use.
[jc: make BLK_SHA1 the fallback default as discussed on list,
e.g. <20170314201424.vccij5z2ortq4a4o@sigill.intra.peff.net>; also
remove SHA1_HEADER and SHA1_HEADER_SQ that are no longer used].
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The current test suite is good at letting you test a
particular version of Git. But it's not very good at letting
you test _two_ versions and seeing how they interact (e.g.,
one cloning from the other).
This commit adds a test harness that will build two
arbitrary versions of git and make it easy to call them from
inside your tests. See the README and the example script for
details.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The last call to the mkstemps() function was removed in commit 659488326
("wrapper.c: delete dead function git_mkstemps()", 22-04-2016). In order
to support platforms without mkstemps(), this functionality was provided,
along with a Makefile build variable (NO_MKSTEMPS), by the gitmkstemps()
function. Remove the dead code, along with the defunct build machinery.
Signed-off-by: Ramsay Jones <ramsay@ramsayjones.plus.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git rebase -i" starts using the recently updated "sequencer" code.
* js/rebase-helper:
rebase -i: use the rebase--helper builtin
rebase--helper: add a builtin helper for interactive rebases
Git's interactive rebase is still implemented as a shell script, despite
its complexity. This implies that it suffers from the portability point
of view, from lack of expressibility, and of course also from
performance. The latter issue is particularly serious on Windows, where
we pay a hefty price for relying so much on POSIX.
Unfortunately, being such a huge shell script also means that we missed
the train when it would have been relatively easy to port it to C, and
instead piled feature upon feature onto that poor script that originally
never intended to be more than a slightly pimped cherry-pick in a loop.
To open the road toward better performance (in addition to all the other
benefits of C over shell scripts), let's just start *somewhere*.
The approach taken here is to add a builtin helper that at first intends
to take care of the parts of the interactive rebase that are most
affected by the performance penalties mentioned above.
In particular, after we spent all those efforts on preparing the sequencer
to process rebase -i's git-rebase-todo scripts, we implement the `git
rebase -i --continue` functionality as a new builtin, git-rebase--helper.
Once that is in place, we can work gradually on tackling the rest of the
technical debt.
Note that the rebase--helper needs to learn about the transient
--ff/--no-ff options of git-rebase, as the corresponding flag is not
persisted to, and re-read from, the state directory.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is similar to many of our uses of sha1-array, but it
overcomes one limitation of a sha1-array: when you are
de-duplicating a large input with relatively few unique
entries, sha1-array uses 20 bytes per non-unique entry.
Whereas this set will use memory linear in the number of
unique entries (albeit a few more than 20 bytes due to
hashmap overhead).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Asciidoctor, an alternative reimplementation of AsciiDoc, still
needs some changes to work with documents meant to be formatted
with AsciiDoc. "make USE_ASCIIDOCTOR=YesPlease" to use it out of
the box to document our pages is getting closer to reality.
* bc/use-asciidoctor-opt:
Documentation: implement linkgit macro for Asciidoctor
Makefile: add a knob to enable the use of Asciidoctor
Documentation: move dblatex arguments into variable
Documentation: add XSLT to fix DocBook for Texinfo
Documentation: sort sources for gitman.texi
Documentation: remove unneeded argument in cat-texi.perl
Documentation: modernize cat-texi.perl
Documentation: fix warning in cat-texi.perl
Rewrite a scripted porcelain "git difftool" in C.
* js/difftool-builtin:
difftool: hack around -Wzero-length-format warning
difftool: retire the scripted version
difftool: implement the functionality in the builtin
difftool: add a skeleton for the upcoming builtin
A few codepaths had to rely on a global variable when sorting
elements of an array because sort(3) API does not allow extra data
to be passed to the comparison function. Use qsort_s() when
natively available, and a fallback implementation of it when not,
to eliminate the need, which is a prerequisite for making the
codepath reentrant.
* rs/qsort-s:
ref-filter: use QSORT_S in ref_array_sort()
string-list: use QSORT_S in string_list_sort()
perf: add basic sort performance test
add QSORT_S
compat: add qsort_s()
Back in the olden days, when all objects were loose and rubber boots were
made out of wood, it made sense to try to share (immutable) objects
between repositories.
Ever since the arrival of pack files, it is but an anachronism.
Let's move the script to the contrib/examples/ directory and no longer
offer it.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The function qsort_s() was introduced with C11 Annex K; it provides the
ability to pass a context pointer to the comparison function, supports
the convention of using a NULL pointer for an empty array and performs a
few safety checks.
Add an implementation based on compat/qsort.c for platforms that lack a
native standards-compliant qsort_s() (i.e. basically everyone). It
doesn't perform the full range of possible checks: It uses size_t
instead of rsize_t and doesn't check nmemb and size against RSIZE_MAX
because we probably don't have the restricted size type defined. For
the same reason it returns int instead of errno_t.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
While Git has traditionally built its documentation using AsciiDoc, some
people wish to use Asciidoctor for speed or other reasons. Add a
Makefile knob, USE_ASCIIDOCTOR, that sets various options in order to
produce acceptable output. For HTML output, XHTML5 was chosen, since
the AsciiDoc options also produce XHTML, albeit XHTML 1.1.
Asciidoctor does not have built-in support for the linkgit macro, but it
is available using the Asciidoctor Extensions Lab. Add a macro to
enable the use of this extension if it is available. Without it, the
linkgit macros are emitted into the output.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It served its purpose, but now we have a builtin difftool. Time for the
Perl script to enjoy Florida.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This adds a builtin difftool that still falls back to the legacy Perl
version, which has been renamed to `legacy-difftool`.
The idea is that the new, experimental, builtin difftool immediately hands
off to the legacy difftool for now, unless the config variable
difftool.useBuiltin is set to true.
This feature flag will be used in the upcoming Git for Windows v2.11.0
release, to allow early testers to opt-in to use the builtin difftool and
flesh out any bugs.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Junio C Hamano
Ævar Arnfjörð Bjarmason
Jeff Smith
Ben Peart
Michael Haggerty
Jeff Hostetler
Nguyễn Thái Ngọc Duy
Jeff King
brian m. carlson
Ramsay Jones
Johannes Schindelin
René Scharfe