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Author SHA1 Message Date
Jeff King
ecb590a9de perf-lib: fix ignored exit code inside loop
When copying the test repository, we try to detect whether
the copy succeeded. However, most of the heavy lifting is
done inside a for loop, where our "break" will lose the exit
code of the failing "cp". We can take advantage of the fact
that we are in a subshell, and just "exit 1" to break out
with a code.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-03-25 10:21:23 -07:00
Junio C Hamano
25f3119000 Merge branch 'jk/repack-pack-writebitmaps-config'
* jk/repack-pack-writebitmaps-config:
  t7700: drop explicit --no-pack-kept-objects from .keep test
  repack: introduce repack.writeBitmaps config option
  repack: simplify handling of --write-bitmap-index
  pack-objects: stop respecting pack.writebitmaps
2014-06-25 12:23:19 -07:00
Jeff King
71d76cb480 repack: introduce repack.writeBitmaps config option
We currently have pack.writeBitmaps, which originally
operated at the pack-objects level. This should really have
been a repack.* option from day one. Let's give it the more
sensible name, but keep the old version as a deprecated
synonym.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-06-10 14:05:19 -07:00
Elia Pinto
4717659144 p5302-pack-index.sh: use the $( ... ) construct for command substitution
The Git CodingGuidelines prefer the $(...) construct for command
substitution instead of using the backquotes `...`.

The backquoted form is the traditional method for command
substitution, and is supported by POSIX.  However, all but the
simplest uses become complicated quickly.  In particular, embedded
command substitutions and/or the use of double quotes require
careful escaping with the backslash character.

The patch was generated by:

for _f in $(find . -name "*.sh")
do
   sed -i 's@`\(.*\)`@$(\1)@g' ${_f}
done

and then carefully proof-read.

Signed-off-by: Elia Pinto <gitter.spiros@gmail.com>
Reviewed-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-04-23 15:17:03 -07:00
Junio C Hamano
0f9e62e084 Merge branch 'jk/pack-bitmap'
Borrow the bitmap index into packfiles from JGit to speed up
enumeration of objects involved in a commit range without having to
fully traverse the history.

* jk/pack-bitmap: (26 commits)
  ewah: unconditionally ntohll ewah data
  ewah: support platforms that require aligned reads
  read-cache: use get_be32 instead of hand-rolled ntoh_l
  block-sha1: factor out get_be and put_be wrappers
  do not discard revindex when re-preparing packfiles
  pack-bitmap: implement optional name_hash cache
  t/perf: add tests for pack bitmaps
  t: add basic bitmap functionality tests
  count-objects: recognize .bitmap in garbage-checking
  repack: consider bitmaps when performing repacks
  repack: handle optional files created by pack-objects
  repack: turn exts array into array-of-struct
  repack: stop using magic number for ARRAY_SIZE(exts)
  pack-objects: implement bitmap writing
  rev-list: add bitmap mode to speed up object lists
  pack-objects: use bitmaps when packing objects
  pack-objects: split add_object_entry
  pack-bitmap: add support for bitmap indexes
  documentation: add documentation for the bitmap format
  ewah: compressed bitmap implementation
  ...
2014-02-27 14:01:48 -08:00
Junio C Hamano
a6bec00145 Merge branch 'jk/mark-edges-uninteresting'
Fix performance regression in v1.8.4.x and later.

* jk/mark-edges-uninteresting:
  list-objects: only look at cmdline trees with edge_hint
  t/perf: time rev-list with UNINTERESTING commits
2014-01-27 10:45:08 -08:00
Jeff King
ea97002fc9 t/perf: time rev-list with UNINTERESTING commits
We time a straight "rev-list --all" and its "--object"
counterpart, both going all the way to the root. However, we
do not time a partial history walk. This patch adds an
extreme case: a walk over a very small slice of history, but
with a very large set of UNINTERESTING tips. This is similar
to the connectivity check run by git on a small fetch, or
the walk done by any pre-receive hooks that want to check
incoming commits.

This test reveals a performance regression in git v1.8.4.2,
caused by fbd4a70 (list-objects: mark more commits as edges
in mark_edges_uninteresting, 2013-08-16):

Test                                             fbd4a703^         fbd4a703
------------------------------------------------------------------------------------------
0001.1: rev-list --all                           0.69(0.67+0.02)   0.69(0.68+0.01) +0.0%
0001.2: rev-list --all --objects                 3.47(3.44+0.02)   3.48(3.44+0.03) +0.3%
0001.4: rev-list $commit --not --all             0.04(0.04+0.00)   0.04(0.04+0.00) +0.0%
0001.5: rev-list --objects $commit --not --all   0.04(0.03+0.00)   0.27(0.24+0.02) +575.0%

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-01-21 14:46:17 -08:00
Vicent Marti
ae4f07fbcc pack-bitmap: implement optional name_hash cache
When we use pack bitmaps rather than walking the object
graph, we end up with the list of objects to include in the
packfile, but we do not know the path at which any tree or
blob objects would be found.

In a recently packed repository, this is fine. A fetch would
use the paths only as a heuristic in the delta compression
phase, and a fully packed repository should not need to do
much delta compression.

As time passes, though, we may acquire more objects on top
of our large bitmapped pack. If clients fetch frequently,
then they never even look at the bitmapped history, and all
works as usual. However, a client who has not fetched since
the last bitmap repack will have "have" tips in the
bitmapped history, but "want" newer objects.

The bitmaps themselves degrade gracefully in this
circumstance. We manually walk the more recent bits of
history, and then use bitmaps when we hit them.

But we would also like to perform delta compression between
the newer objects and the bitmapped objects (both to delta
against what we know the user already has, but also between
"new" and "old" objects that the user is fetching). The lack
of pathnames makes our delta heuristics much less effective.

This patch adds an optional cache of the 32-bit name_hash
values to the end of the bitmap file. If present, a reader
can use it to match bitmapped and non-bitmapped names during
delta compression.

Here are perf results for p5310:

Test                      origin/master       HEAD^                      HEAD
-------------------------------------------------------------------------------------------------
5310.2: repack to disk    36.81(37.82+1.43)   47.70(48.74+1.41) +29.6%   47.75(48.70+1.51) +29.7%
5310.3: simulated clone   30.78(29.70+2.14)   1.08(0.97+0.10) -96.5%     1.07(0.94+0.12) -96.5%
5310.4: simulated fetch   3.16(6.10+0.08)     3.54(10.65+0.06) +12.0%    1.70(3.07+0.06) -46.2%
5310.6: partial bitmap    36.76(43.19+1.81)   6.71(11.25+0.76) -81.7%    4.08(6.26+0.46) -88.9%

You can see that the time spent on an incremental fetch goes
down, as our delta heuristics are able to do their work.
And we save time on the partial bitmap clone for the same
reason.

Signed-off-by: Vicent Marti <tanoku@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-30 12:19:23 -08:00
Jeff King
bbcefa1f3f t/perf: add tests for pack bitmaps
This adds a few basic perf tests for the pack bitmap code to
show off its improvements. The tests are:

  1. How long does it take to do a repack (it gets slower
     with bitmaps, since we have to do extra work)?

  2. How long does it take to do a clone (it gets faster
     with bitmaps)?

  3. How does a small fetch perform when we've just
     repacked?

  4. How does a clone perform when we haven't repacked since
     a week of pushes?

Here are results against linux.git:

Test                      origin/master       this tree
-----------------------------------------------------------------------
5310.2: repack to disk    33.64(32.64+2.04)   67.67(66.75+1.84) +101.2%
5310.3: simulated clone   30.49(29.47+2.05)   1.20(1.10+0.10) -96.1%
5310.4: simulated fetch   3.49(6.79+0.06)     5.57(22.35+0.07) +59.6%
5310.6: partial bitmap    36.70(43.87+1.81)   8.18(21.92+0.73) -77.7%

You can see that we do take longer to repack, but we do way
better for further clones. A small fetch performs a bit
worse, as we spend way more time on delta compression (note
the heavy user CPU time, as we have 8 threads) due to the
lack of name hashes for the bitmapped objects.

The final test shows how the bitmaps degrade over time
between packs. There's still a significant speedup over the
non-bitmap case, but we don't do quite as well (we have to
spend time accessing the "new" objects the old fashioned
way, including delta compression).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-30 12:19:23 -08:00
Junio C Hamano
73b063130b Merge branch 'tg/diff-no-index-refactor'
"git diff ../else/where/A ../else/where/B" when ../else/where is
clearly outside the repository, and "git diff --no-index A B", do
not have to look at the index at all, but we used to read the index
unconditionally.

* tg/diff-no-index-refactor:
  diff: avoid some nesting
  diff: add test for --no-index executed outside repo
  diff: don't read index when --no-index is given
  diff: move no-index detection to builtin/diff.c
2013-12-27 14:58:17 -08:00
Thomas Gummerer
6df5762db3 diff: don't read index when --no-index is given
git diff --no-index ... currently reads the index, during setup, when
calling gitmodules_config().  This results in worse performance when the
index is not actually needed.  This patch avoids calling
gitmodules_config() when the --no-index option is given.  The times for
executing "git diff --no-index" in the WebKit repository are improved as
follows:

Test                      HEAD~3            HEAD
------------------------------------------------------------------
4001.1: diff --no-index   0.24(0.15+0.09)   0.01(0.00+0.00) -95.8%

An additional improvement of this patch is that "git diff --no-index" no
longer breaks when the index file is corrupt, which makes it possible to
use it for investigating the broken repository.

To improve the possible usage as investigation tool for broken
repositories, setup_git_directory_gently() is also not called when the
--no-index option is given.

Also add a test to guard against future breakages, and a performance
test to show the improvements.

Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-12 12:23:02 -08:00
Jonathan Nieder
c74c72034f test: replace shebangs with descriptions in shell libraries
A #! line in these files is misleading, since these scriptlets are
meant to be sourced with '.' (using whatever shell sources them)
instead of run directly using the interpreter named on the #! line.

Removing the #! line shouldn't hurt syntax highlighting since
these files have filenames ending with '.sh'.  For documentation,
add a brief description of how the files are meant to be used in
place of the shebang line.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-11-26 14:23:52 -08:00
Junio C Hamano
a5203a3f04 Merge branch 'lf/echo-n-is-not-portable'
* lf/echo-n-is-not-portable:
  Avoid using `echo -n` anywhere
2013-08-01 11:52:43 -07:00
Lukas Fleischer
19c3c5fdcb Avoid using echo -n anywhere
`echo -n` is non-portable. The POSIX specification says:

    Conforming applications that wish to do prompting without <newline>
    characters or that could possibly be expecting to echo a -n, should
    use the printf utility derived from the Ninth Edition system.

Since all of the affected shell scripts use a POSIX shell shebang,
replace `echo -n` invocations with printf.

Signed-off-by: Lukas Fleischer <git@cryptocrack.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-07-29 09:56:58 -07:00
Junio C Hamano
04f2ddda84 Merge branch 'tr/test-v-and-v-subtest-only'
Allows N instances of tests run in parallel, each running 1/N parts
of the test suite under Valgrind, to speed things up.

* tr/test-v-and-v-subtest-only:
  perf-lib: fix start/stop of perf tests
  test-lib: support running tests under valgrind in parallel
  test-lib: allow prefixing a custom string before "ok N" etc.
  test-lib: valgrind for only tests matching a pattern
  test-lib: verbose mode for only tests matching a pattern
  test-lib: self-test that --verbose works
  test-lib: rearrange start/end of test_expect_* and test_skip
  test-lib: refactor $GIT_SKIP_TESTS matching
  test-lib: enable MALLOC_* for the actual tests
2013-07-05 01:15:48 -07:00
Thomas Gummerer
62a23c9f58 perf-lib: fix start/stop of perf tests
ae75342 test-lib: rearrange start/end of test_expect_* and test_skip
changed the way tests are started/stopped, but did not update the perf
tests.  They were therefore giving the wrong output, because of the
wrong test count.  Fix this by starting and stopping the tests
correctly.

Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
Acked-by: Thomas Rast <trast@inf.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-29 18:45:24 -07:00
W. Trevor King
283efb0108 Documentation: Update 'linux-2.6.git' -> 'linux.git'
The 3.x tree has been out for a while now.  The -2.6 repository name
survived the initial release [1], but kernel.org now only lists
'linux.git' (for aegl as well as torvalds) [2].

[1]: http://article.gmane.org/gmane.linux.kernel/1147422
  On 2011-05-30 01:47:57 GMT, Linus Torvalds wrote:
  > ... yes, that means that my git tree is still called
  > "linux-2.6.git" on kernel.org.
[2]: http://git.kernel.org/cgit/

Signed-off-by: W. Trevor King <wking@tremily.us>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-22 23:36:48 -07:00
Junio C Hamano
08bcd774f4 Merge branch 'rs/discard-index-discard-array'
* rs/discard-index-discard-array:
  read-cache: free cache in discard_index
  read-cache: add simple performance test
2013-06-20 16:02:30 -07:00
René Scharfe
1ecb5ff141 read-cache: add simple performance test
Add the helper test-read-cache, which can be used to call read_cache and
discard_cache in a loop as well as a performance check based on it.

Signed-off-by: René Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-09 17:03:00 -07:00
Junio C Hamano
ed73fe5642 Merge branch 'tr/line-log'
* tr/line-log:
  git-log(1): remove --full-line-diff description
  line-log: fix documentation formatting
  log -L: improve comments in process_all_files()
  log -L: store the path instead of a diff_filespec
  log -L: test merge of parallel modify/rename
  t4211: pass -M to 'git log -M -L...' test
  log -L: fix overlapping input ranges
  log -L: check range set invariants when we look it up
  Speed up log -L... -M
  log -L: :pattern:file syntax to find by funcname
  Implement line-history search (git log -L)
  Export rewrite_parents() for 'log -L'
  Refactor parse_loc
2013-06-02 16:00:44 -07:00
Thomas Rast
12da1d1f6f Implement line-history search (git log -L)
This is a rewrite of much of Bo's work, mainly in an effort to split
it into smaller, easier to understand routines.

The algorithm is built around the struct range_set, which encodes a
series of line ranges as intervals [a,b).  This is used in two
contexts:

* A set of lines we are tracking (which will change as we dig through
  history).
* To encode diffs, as pairs of ranges.

The main routine is range_set_map_across_diff().  It processes the
diff between a commit C and some parent P.  It determines which diff
hunks are relevant to the ranges tracked in C, and computes the new
ranges for P.

The algorithm is then simply to process history in topological order
from newest to oldest, computing ranges and (partial) diffs.  At
branch points, we need to merge the ranges we are watching.  We will
find that many commits do not affect the chosen ranges, and mark them
TREESAME (in addition to those already filtered by pathspec limiting).
Another pass of history simplification then gets rid of such commits.

This is wired as an extra filtering pass in the log machinery.  This
currently only reduces code duplication, but should allow for other
simplifications and options to be used.

Finally, we hook a diff printer into the output chain.  Ideally we
would wire directly into the diff logic, to optionally use features
like word diff.  However, that will require some major reworking of
the diff chain, so we completely replace the output with our own diff
for now.

As this was a GSoC project, and has quite some history by now, many
people have helped.  In no particular order, thanks go to

  Jakub Narebski <jnareb@gmail.com>
  Jens Lehmann <Jens.Lehmann@web.de>
  Jonathan Nieder <jrnieder@gmail.com>
  Junio C Hamano <gitster@pobox.com>
  Ramsay Jones <ramsay@ramsay1.demon.co.uk>
  Will Palmer <wmpalmer@gmail.com>

Apologies to everyone I forgot.

Signed-off-by: Bo Yang <struggleyb.nku@gmail.com>
Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-03-28 10:29:22 -07:00
Antoine Pelisse
ca70c9ea72 perf: update documentation of GIT_PERF_REPEAT_COUNT
Currently the documentation of GIT_PERF_REPEAT_COUNT says the default is
five while "perf-lib.sh" uses a value of three as a default.

Update the documentation so that it is consistent with the code.

Signed-off-by: Antoine Pelisse <apelisse@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-03-09 11:13:12 -08:00
Junio C Hamano
70dac5f44d Merge branch 'ep/malloc-check-perturb'
Fixes a brown-paper bag bug.

* ep/malloc-check-perturb:
  MALLOC_CHECK: enable it, unless disabled explicitly
2012-10-01 12:59:06 -07:00
René Scharfe
ee1431bfc5 MALLOC_CHECK: enable it, unless disabled explicitly
The malloc checks in tests are currently disabled.  Actually evaluate
the variable for turning them off and enable them if it's unset.

Also use this opportunity to give it the more descriptive and
consistent name TEST_NO_MALLOC_CHECK.

Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-09-26 23:39:13 -07:00
Junio C Hamano
0ec6aa567a Merge branch 'ep/malloc-check-perturb'
Run our test scripts with MALLOC_CHECK_ and MALLOC_PERTURB_, the
built-in memory access checking facility GNU libc has.

* ep/malloc-check-perturb:
  MALLOC_CHECK: various clean-ups
  Add MALLOC_CHECK_ and MALLOC_PERTURB_ libc env to the test suite for detecting heap corruption
2012-09-25 10:40:15 -07:00
Junio C Hamano
1b3185fc2b MALLOC_CHECK: various clean-ups
The most important in this change is to avoid affecting anything
when test-lib is used from perf-lib.  It also limits the effect of
the MALLOC_CHECK only to what is run inside the actual test, and
uses a fixed MALLOC_PERTURB_ in order to avoid hurting repeatability
of the tests.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-09-17 22:00:27 -07:00
Ramkumar Ramachandra
5805853f22 t/perf: add "trash directory" to .gitignore
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-09-17 14:27:55 -07:00
Michał Kiedrowicz
d17cf5f3a3 tests: Introduce test_seq
Jeff King wrote:

	The seq command is GNU-ism, and is missing at least in older BSD
	releases and their derivatives, not to mention antique
	commercial Unixes.

	We already purged it in b3431bc (Don't use seq in tests, not
	everyone has it, 2007-05-02), but a few new instances have crept
	in. They went unnoticed because they are in scripts that are not
	run by default.

Replace them with test_seq that is implemented with a Perl snippet
(proposed by Jeff).  This is better than inlining this snippet
everywhere it's needed because it's easier to read and it's easier
to change the implementation (e.g. to C) if we ever decide to remove
Perl from the test suite.

Note that test_seq is not a complete replacement for seq(1).  It
just has what we need now, in addition that it makes it possible for
us to do something like "test_seq a m" if we wanted to in the
future.

There are also many places that do `for i in 1 2 3 ...` but I'm not sure
if it's worth converting them to test_seq.  That would introduce running
more processes of Perl.

Signed-off-by: Michał Kiedrowicz <michal.kiedrowicz@gmail.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-08-04 16:06:07 -07:00
Junio C Hamano
cc13431a49 Merge branch 'nd/threaded-index-pack'
Enables threading in index-pack to resolve base data in parallel.

By Nguyễn Thái Ngọc Duy (3) and Ramsay Jones (1)
* nd/threaded-index-pack:
  index-pack: disable threading if NO_PREAD is defined
  index-pack: support multithreaded delta resolving
  index-pack: restructure pack processing into three main functions
  compat/win32/pthread.h: Add an pthread_key_delete() implementation
2012-05-14 11:50:40 -07:00
Nguyễn Thái Ngọc Duy
b8a2486f15 index-pack: support multithreaded delta resolving
This puts delta resolving on each base on a separate thread, one base
cache per thread. Per-thread data is grouped in struct thread_local.
When running with nr_threads == 1, no pthreads calls are made. The
system essentially runs in non-thread mode.

An experiment on a Xeon 24 core machine with git.git shows that
performance does not increase proportional to the number of cores. So
by default, we use maximum 3 cores. Some numbers with --threads from 1
to 16:

1..4
real    0m8.003s  0m5.307s  0m4.321s  0m3.830s
user    0m7.720s  0m8.009s  0m8.133s  0m8.305s
sys     0m0.224s  0m0.372s  0m0.360s  0m0.360s

5..8
real    0m3.727s  0m3.604s  0m3.332s  0m3.369s
user    0m9.361s  0m9.817s  0m9.525s  0m9.769s
sys     0m0.584s  0m0.624s  0m0.540s  0m0.560s

9..12
real    0m3.036s  0m3.139s  0m3.177s  0m2.961s
user    0m8.977s  0m10.205s 0m9.737s  0m10.073s
sys     0m0.596s  0m0.680s  0m0.684s  0m0.680s

13..16
real    0m2.985s  0m2.894s  0m2.975s  0m2.971s
user    0m9.825s  0m10.573s 0m10.833s 0m11.361s
sys     0m0.788s  0m0.732s  0m0.904s  0m1.016s

On an Intel dual core and linux-2.6.git

1..4
real    2m37.789s 2m7.963s  2m0.920s  1m58.213s
user    2m28.415s 2m52.325s 2m50.176s 2m41.187s
sys     0m7.808s  0m11.181s 0m11.224s 0m10.731s

Thanks Ramsay Jones for troubleshooting and support on MinGW platform.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-05-07 15:48:15 -07:00
Thomas Rast
745950ce0e p4000: use -3000 when promising -3000
The 'log -3000 (baseline)' test accidentally still used -1000 from an
earlier version.

Noticed-by: Lawrence Holding <Lawrence.Holding@cubic.com>
Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-03-09 02:07:23 -08:00
Thomas Rast
561ae06735 perf: export some important test-lib variables
The only bug right now is that $GIT_TEST_CMP is needed for test_cmp to
work.

However, we also export the three most important paths for tests:

  TEST_DIRECTORY
  TRASH_DIRECTORY
  GIT_BUILD_DIR

Since they are available within test_expect_success, a future test
writer may expect them to also be defined in test_perf.

Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-03-08 12:07:50 -08:00
Thomas Rast
1cbc32403b perf: load test-lib-functions from the correct directory
Loading it in the subshells still referred to $TEST_DIRECTORY/..,
which was only correct in preliminary versions of perf-lib.sh

Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-03-08 11:38:09 -08:00
Thomas Rast
85551232b5 perf: compare diff algorithms
8c912ee (teach --histogram to diff, 2011-07-12) claimed histogram diff
was faster than both Myers and patience.

We have since incorporated a performance testing framework, so add a
test that compares the various diff tasks performed in a real 'log -p'
workload.  This does indeed show that histogram diff slightly beats
Myers, while patience is much slower than the others.

Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-03-06 11:48:11 -08:00
Thomas Rast
134593c8ca Add a performance test for git-grep
The only catch is that we don't really know what our repo contains, so
we have to ignore any possible "not found" status from git-grep.

Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-02-17 08:21:34 -08:00
Thomas Rast
342e9ef2d9 Introduce a performance testing framework
This introduces a performance testing framework under t/perf/.  It
tries to be as close to the test-lib.sh infrastructure as possible,
and thus should be easy to get used to for git developers.

The following points were considered for the implementation:

1. You usually want to compare arbitrary revisions/build trees against
   each other.  They may not have the performance test under
   consideration, or even the perf-lib.sh infrastructure.

   To cope with this, the 'run' script lets you specify arbitrary
   build dirs and revisions.  It even automatically builds the revisions
   if it doesn't have them at hand yet.

2. Usually you would not want to run all tests.  It would take too
   long anyway.  The 'run' script lets you specify which tests to run;
   or you can also do it manually.  There is a Makefile for
   discoverability and 'make clean', but it is not meant for
   real-world use.

3. Creating test repos from scratch in every test is extremely
   time-consuming, and shipping or downloading such large/weird repos
   is out of the question.

   We leave this decision to the user.  Two different sizes of test
   repos can be configured, and the scripts just copy one or more of
   those (using hardlinks for the object store).  By default it tries
   to use the build tree's git.git repository.

   This is fairly fast and versatile.  Using a copy instead of a clone
   preserves many properties that the user may want to test for, such
   as lots of loose objects, unpacked refs, etc.

Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-02-17 08:21:22 -08:00