delta/git.git/t/perf, branch pb/commit-editmsg-path

perf: make the tests work without a worktree

2016-05-31T20:44:59+00:00

In regular repositories $source_git and $objects_dir contain relative
paths based on $source.  Go there to allow cp to resolve them.

Signed-off-by: Rene Scharfe 
Signed-off-by: Junio C Hamano

perf: run "rebase -i" under perf

2016-05-13T18:07:12+00:00

This developer spent a lot of time trying to speed up the interactive
rebase, in particular on Windows. And will continue to do so.

To make it easier to demonstrate the performance improvement, let's have
a reproducible performance test.

The topic branch we use to test performance was found using these shell
commands (essentially searching for a long-enough topic branch in Git's
own history that touched the same file multiple times):

	git rev-list --parents origin/master |
	grep ' .* ' |
	while read commit rest
	do
		patch_count=$(git rev-list --count $commit^..$commit^2)
		test $patch_count -gt 20 || continue

		merges="$(git rev-list --parents $commit^..$commit^2 |
			grep ' .* ')"
		test -z "$merges" || continue

		patches_per_file="$(git log --pretty=%H --name-only \
				$commit^..$commit^2 |
			grep -v '^$' |
			sort |
			uniq -c -d |
			sort -n -r)"
		test -n "$patches_per_file" &&
		test 20 -lt $(echo "$patches_per_file" |
			sed -n '1s/^ *\([0-9]*\).*/\1/p') || continue

		printf 'commit %s\n%s\n' "$commit" "$patches_per_file"
	done

Note that we can get away with *not* having to reset to the original
branch tip before rebasing: we switch the first two "pick" lines every
time, so we end up with the same patch order after two rebases, and the
complexity of both rebases is equivalent.

Signed-off-by: Johannes Schindelin 
Signed-off-by: Junio C Hamano

perf: make the tests work in worktrees

2016-05-13T18:04:07+00:00

This patch makes perf-lib.sh more robust so that it can run correctly
even inside a worktree. For example, it assumed that $GIT_DIR/objects is
the objects directory (which is not the case for worktrees) and it used
the commondir file verbatim, even if it contained a relative path.

Furthermore, the setup code expected `git rev-parse --git-dir` to spit
out a relative path, which is also not true for worktrees. Let's just
change the code to accept both relative and absolute paths, by avoiding
the `cd` into the copied working directory.

Signed-off-by: Johannes Schindelin 
Signed-off-by: Junio C Hamano

perf: let's disable symlinks when they are not available

2016-05-13T18:03:11+00:00

We already have a perfectly fine prereq to tell us whether it is safe to
use symlinks. So let's use it.

This fixes the performance tests in Git for Windows' SDK, where symlinks
are not really available ([*1*]). This is not an issue with Git for
Windows itself because it configures core.symlinks=false in its system
config.  However, the system config is disabled for the performance
tests, for obvious reasons: we want them to be independent of the
vagaries of any local configuration.

Footnote *1*: Windows has symbolic links. Git for Windows disables them
by default, though (for example: in standard setups, non-admins lack the
privilege to create symbolic links). For details, see
https://github.com/git-for-windows/git/wiki/Symbolic-Links

Signed-off-by: Johannes Schindelin 
Signed-off-by: Junio C Hamano

resolve_gitlink_ref: ignore non-repository paths

2016-01-25T19:42:13+00:00

When we want to look up a submodule ref, we use
get_ref_cache(path) to find or auto-create its ref cache.
But if we feed a path that isn't actually a git repository,
we blindly create the ref cache, and then may die deeper in
the code when we try to access it. This is a problem because
many callers speculatively feed us a path that looks vaguely
like a repository, and expect us to tell them when it is
not.

This patch teaches resolve_gitlink_ref to reject
non-repository paths without creating a ref_cache. This
avoids the die(), and also performs better if you have a
large number of these faux-submodule directories (because
the ref_cache lookup is linear, under the assumption that
there won't be a large number of submodules).

To accomplish this, we also break get_ref_cache into two
pieces: the lookup and auto-creation (the latter is lumped
into create_ref_cache). This lets us first cheaply ask our
cache "is it a submodule we know about?" If so, we can avoid
repeating our filesystem lookup. So lookups of real
submodules are not penalized; they examine the submodule's
.git directory only once.

The test in t3000 demonstrates a case where this improves
correctness (we used to just die). The new perf case in
p7300 shows off the speed improvement in an admittedly
pathological repository:

Test                  HEAD^               HEAD
----------------------------------------------------------------
7300.4: ls-files -o   66.97(66.15+0.87)   0.33(0.08+0.24) -99.5%

Signed-off-by: Jeff King 
Signed-off-by: Junio C Hamano

filter-branch: skip index read/write when possible

2015-11-06T17:35:49+00:00

If the user specifies an index filter but not a tree filter,
filter-branch cleverly avoids checking out the tree
entirely. But we don't do the next level of optimization: if
you have no index or tree filter, we do not need to read the
index at all.

This can greatly speed up cases where we are only changing
the commit objects (e.g., cementing a graft into place).
Here are numbers from the newly-added perf test:

  Test                  HEAD^              HEAD
  ---------------------------------------------------------------
  7000.2: noop filter   13.81(4.95+0.83)   5.43(0.42+0.43) -60.7%

Signed-off-by: Jeff King 
Signed-off-by: Junio C Hamano

Merge branch 'sb/perf-without-installed-git'

2015-10-15T22:43:37+00:00

Performance-measurement tests did not work without an installed Git.

* sb/perf-without-installed-git:
  t/perf: make runner work even if Git is not installed

t/perf: make runner work even if Git is not installed

2015-09-25T17:44:59+00:00

aggregate.perl did not work when Git.pm is not installed to a directory
contained in the default Perl library path list or PERLLIB.
This commit prepends the Perl library path of the current Git source
tree to enable this.

Note that this commit adds a hard-coded relative path

  use lib '../../perl/blib/lib';

instead of the flexible environment-based variant

  use lib (split(/:/, $ENV{GITPERLLIB}));

which is used in tests written in Perl.
The hard-coded variant is used because the whole performance test
framework does it that way (and GITPERLLIB is not set there).

Signed-off-by: Stephan Beyer 
Signed-off-by: Junio C Hamano

Merge branch 'ee/clean-remove-dirs'

2015-08-03T18:01:13+00:00

Replace "is this subdirectory a separate repository that should not
be touched?" check "git clean" does by checking if it has .git/HEAD
using the submodule-related code with a more optimized check.

* ee/clean-remove-dirs:
  read_gitfile_gently: fix use-after-free
  clean: improve performance when removing lots of directories
  p7300: add performance tests for clean
  t7300: add tests to document behavior of clean and nested git
  setup: sanity check file size in read_gitfile_gently
  setup: add gentle version of read_gitfile

p5310: Fix broken && chain in performance test

2015-06-26T22:41:50+00:00

Signed-off-by: Stefan Beller 
Signed-off-by: Junio C Hamano