Commit Graph

33372 Commits

Author SHA1 Message Date
Junio C Hamano
faf8fde514 Merge branch 'mv/sequencer-pick-error-diag'
Fix "git cherry-pick $annotated_tag", which was mistakenly rejected.

* mv/sequencer-pick-error-diag:
  cherry-pick: picking a tag that resolves to a commit is OK
2013-05-09 13:30:19 -07:00
Junio C Hamano
7c0b0d8dea cherry-pick: picking a tag that resolves to a commit is OK
Earlier, 21246dbb9e (cherry-pick: make sure all input objects are
commits, 2013-04-11) tried to catch an unlikely "git cherry-pick $blob"
as an error, but broke a more important use case to cherry-pick a
tag that points at a commit.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-09 13:29:53 -07:00
Junio C Hamano
07e03d4665 Merge branch 'tr/copy-revisions-from-stdin' into maint
* tr/copy-revisions-from-stdin:
  read_revisions_from_stdin: make copies for handle_revision_arg
2013-05-09 12:42:17 -07:00
René Scharfe
ea2d20d4c2 t5004: avoid using tar for checking emptiness of archive
Test 2 of t5004 checks if a supposedly empty tar archive really
contains no files.  24676f02 (t5004: fix issue with empty archive test
and bsdtar) removed our commit hash to make it work with bsdtar, but
the test still fails on NetBSD and OpenBSD, which use their own tar
that considers a tar file containing only NULs as broken.

Here's what the different archivers do when asked to create a tar
file without entries:

	$ uname -v
	NetBSD 6.0.1 (GENERIC)
	$ gtar --version | head -1
	tar (GNU tar) 1.26
	$ bsdtar --version
	bsdtar 2.8.4 - libarchive 2.8.4

	$ : >zero.tar
	$ perl -e 'print "\0" x 10240' >tenk.tar
	$ sha1 zero.tar tenk.tar
	SHA1 (zero.tar) = da39a3ee5e6b4b0d3255bfef95601890afd80709
	SHA1 (tenk.tar) = 34e163be8e43c5631d8b92e9c43ab0bf0fa62b9c

	$ : | tar cf - -T - | sha1
	da39a3ee5e6b4b0d3255bfef95601890afd80709
	$ : | gtar cf - -T - | sha1
	34e163be8e43c5631d8b92e9c43ab0bf0fa62b9c
	$ : | bsdtar cf - -T - | sha1
	34e163be8e43c5631d8b92e9c43ab0bf0fa62b9c

So NetBSD's native tar creates an empty file, while GNU tar and bsdtar
both give us 10KB of NULs -- just like git archive with an empty tree.
Now let's see how the archivers handle these two kinds of empty tar
files:

	$ tar tf zero.tar; echo $?
	tar: Unexpected EOF on archive file
	1
	$ gtar tf zero.tar; echo $?
	gtar: This does not look like a tar archive
	gtar: Exiting with failure status due to previous errors
	2
	$ bsdtar tf zero.tar; echo $?
	0

	$ tar tf tenk.tar; echo $?
	tar: Cannot identify format. Searching...
	tar: End of archive volume 1 reached
	tar: Sorry, unable to determine archive format.
	1
	$ gtar tf tenk.tar; echo $?
	0
	$ bsdtar tf tenk.tar; echo $?
	0

NetBSD's tar complains about both, bsdtar happily accepts any of them
and GNU tar doesn't like zero-length archive files.  So the safest
course of action is to stay with our block-of-NULs format which is
compatible with GNU tar and bsdtar, as we can't make NetBSD's native
tar happy anyway.

We can simplify our test, however, by taking tar out of the picture.
Instead of extracting the archive and checking for the non-presence of
files, check if the file has a size of 10KB and contains only NULs.
This makes t5004 pass on NetBSD and OpenBSD.

Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-09 12:41:31 -07:00
René Scharfe
56ee96572a t5004: resurrect original empty tar archive test
Add a test to verify the emptiness of an archive by extracting its
contents.  Don't run this test if the version of tar doesn't support
archives containing only a comment header, though.

The existing check 'tar archive of empty tree is empty' used to work
like that (minus the tar capability check) but was changed to depend
on the exact representation of empty tar files created by git archive
instead of on the behaviour of tar in order to avoid issues with
different tar versions.

The different approaches test different things: The existing one is
for empty trees, for which we know the exact expected output and thus
we can simply check it without extracting; the new one is for commits
with empty trees, whose archives include stamps and so the more
"natural" check by extraction is a better fit because it focuses on
the interesting aspect, namely the absence of any archive entries.

Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-09 12:22:31 -07:00
René Scharfe
71a19a3744 t5004: avoid using tar for checking emptiness of archive
Test 2 of t5004 checks if a supposedly empty tar archive really
contains no files.  24676f02 (t5004: fix issue with empty archive test
and bsdtar) removed our commit hash to make it work with bsdtar, but
the test still fails on NetBSD and OpenBSD, which use their own tar
that considers a tar file containing only NULs as broken.

Here's what the different archivers do when asked to create a tar
file without entries:

	$ uname -v
	NetBSD 6.0.1 (GENERIC)
	$ gtar --version | head -1
	tar (GNU tar) 1.26
	$ bsdtar --version
	bsdtar 2.8.4 - libarchive 2.8.4

	$ : >zero.tar
	$ perl -e 'print "\0" x 10240' >tenk.tar
	$ sha1 zero.tar tenk.tar
	SHA1 (zero.tar) = da39a3ee5e6b4b0d3255bfef95601890afd80709
	SHA1 (tenk.tar) = 34e163be8e43c5631d8b92e9c43ab0bf0fa62b9c

	$ : | tar cf - -T - | sha1
	da39a3ee5e6b4b0d3255bfef95601890afd80709
	$ : | gtar cf - -T - | sha1
	34e163be8e43c5631d8b92e9c43ab0bf0fa62b9c
	$ : | bsdtar cf - -T - | sha1
	34e163be8e43c5631d8b92e9c43ab0bf0fa62b9c

So NetBSD's native tar creates an empty file, while GNU tar and bsdtar
both give us 10KB of NULs -- just like git archive with an empty tree.
Now let's see how the archivers handle these two kinds of empty tar
files:

	$ tar tf zero.tar; echo $?
	tar: Unexpected EOF on archive file
	1
	$ gtar tf zero.tar; echo $?
	gtar: This does not look like a tar archive
	gtar: Exiting with failure status due to previous errors
	2
	$ bsdtar tf zero.tar; echo $?
	0

	$ tar tf tenk.tar; echo $?
	tar: Cannot identify format. Searching...
	tar: End of archive volume 1 reached
	tar: Sorry, unable to determine archive format.
	$ gtar tf tenk.tar; echo $?
	0
	$ bsdtar tf tenk.tar; echo $?
	0

NetBSD's tar complains about both, bsdtar happily accepts any of them
and GNU tar doesn't like zero-length archive files.  So the safest
course of action is to stay with our block-of-NULs format which is
compatible with GNU tar and bsdtar, as we can't make NetBSD's native
tar happy anyway.

We can simplify our test, however, by taking tar out of the picture.
Instead of extracting the archive and checking for the non-presence of
files, check if the file has a size of 10KB and contains only NULs.
This makes t5004 pass on NetBSD and OpenBSD.

Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-09 12:20:40 -07:00
René Scharfe
abdb9b2e4f t5004: ignore pax global header file
Versions of tar that don't know pax headers -- like the ones in NetBSD 6
and OpenBSD 5.2 -- extract them as regular files.  Explicitly ignore the
file created for our global header when checking the list of extracted
files, as this is normal and harmless fall-back behaviour.  This fixes
test 3 of t5004 on these platforms.

Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-09 12:18:57 -07:00
David Aguilar
e2161bc385 mergetools/kdiff3: do not use --auto when diffing
The `kdiff3 --auto` help message is, "No GUI if all conflicts are auto-
solvable."  This flag was carried over from the original mergetool
commands.  diff_cmd() is for two-way comparisons only so remove the
superfluous flag.

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-09 11:59:39 -07:00
Felipe Contreras
b120ef3eac transport-helper: trivial style cleanup
Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-09 11:33:01 -07:00
Paul Walmsley
a7b102302a git-svn: added an --include-path flag
The SVN::Fetcher module is now able to filter for inclusion as well
as exclusion (as used by --ignore-path). Also added tests, documentation
changes and git completion script.

If you have an SVN repository with many top level directories and you
only want a git-svn clone of some of them then using --ignore-path is
difficult as it requires a very long regexp. In this case it's much
easier to filter for inclusion.

[ew: remove trailing whitespace]

Signed-off-by: Paul Walmsley <pjwhams@gmail.com>
Signed-off-by: Eric Wong <normalperson@yhbt.net>
2013-05-09 01:13:36 +00:00
Jonathan Nieder
d301f18160 Git::SVN::*: add missing "NAME" section to perldoc
lexgrog(1) relies on the NAME section to find a manpage's subject's
name and description for easy access later using "man -k".  Add the
section it expects.

Noticed using lintian.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Eric Wong <normalperson@yhbt.net>
2013-05-09 01:07:58 +00:00
Michael Contreras
e234ac9d47 git-svn: avoid self-referencing mergeinfo
When svn.pushmergeinfo is set, the target branch is included in the
mergeinfo if it was previously merged into one of the source branches.
SVN does not do this.

Remove merge target branch path from resulting mergeinfo when
svn.pushmergeinfo is set to better match the behavior of SVN. Update the
svn-mergeinfo-push test.

[ew: 80 columns]

Signed-off-by: Michael Contreras <michael@inetric.com>
Reported-by: Avishay Lavie <avishay.lavie@gmail.com>
Acked-by: Eric Wong <normalperson@yhbt.net>
2013-05-09 01:07:39 +00:00
Vikrant Varma
f3f8af0e54 merge: use help_unknown_ref()
Use help.c:help_unknown_ref() instead of die() to provide a
friendlier error message before exiting, when one of the refs
specified in a merge is unknown.

Signed-off-by: Vikrant Varma <vikrant.varma94@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-08 15:34:33 -07:00
Vikrant Varma
e56181060e help: add help_unknown_ref()
When the user gives an unknown string to a command that expects to
get a ref, we could be more helpful than just saying "that's not a
ref" and die.

Add helper function help_unknown_ref() to take care of displaying an
error message along with a list of suggested refs the user might
have meant.  An interaction with "git merge" might go like this:

	$ git merge foo
	merge: foo - not something we can merge

	Did you mean one of these?
	    origin/foo
	    upstream/foo

Signed-off-by: Vikrant Varma <vikrant.varma94@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-08 15:31:54 -07:00
Felipe Contreras
734b2f0532 completion: synchronize zsh wrapper
So it's closer to the full zsh wrapper.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-08 11:44:32 -07:00
Felipe Contreras
2bcf694b18 completion: cleanup zsh wrapper
There's no need for a separate function; we can call
'emulate -k ksh func'.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-08 11:44:30 -07:00
Junio C Hamano
9b795193a6 Update draft release notes for 1.8.3
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-07 22:50:05 -07:00
Felipe Contreras
0df860383e remote-helpers: trivial cleanup
The comment was copied from hg-fast-export, not used anymore.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-07 22:42:20 -07:00
Felipe Contreras
435f39a3e8 remote-bzr: fix for disappeared revisions
It's possible that the previous tip goes away, we should not assume it's
always present. Fortunately we are only using it to calculate the
progress to display to the user, so only that needs to be fixed.

Also, add a test that triggers this issue.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-07 22:38:40 -07:00
Junio C Hamano
3b892dc828 Merge git://github.com/git-l10n/git-po
* git://github.com/git-l10n/git-po:
  l10n: zh_CN.po: translate 44 messages (2080t0f0u)
  l10n: de.po: translate 44 new messages
  l10n: Update Vietnamese translation (2080t0f0u)
  l10n: Update Swedish translation (2080t0f0u)
  l10n: git.pot: v1.8.3 round 2 (44 new, 12 removed)
2013-05-07 18:24:31 -07:00
Jiang Xin
4dcdc3d8cc l10n: zh_CN.po: translate 44 messages (2080t0f0u)
Translate 44 new messages came from git.pot update in c6bc7d4
(l10n: git.pot: v1.8.3 round 2 (44 new, 12 removed))

Signed-off-by: Jiang Xin <worldhello.net@gmail.com>
2013-05-08 08:13:32 +08:00
Felipe Contreras
45c5d4a56b fast-{import,export}: use get_sha1_hex() to read from marks file
It's wrong to call get_sha1() if they should be SHA-1s, plus
inefficient.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-07 16:20:40 -07:00
Ralf Thielow
a09ab03a5b l10n: de.po: translate 44 new messages
Translate 44 new messages came from git.pot update in
c6bc7d4 (l10n: git.pot: v1.8.3 round 2 (44 new, 12 removed)).

Signed-off-by: Ralf Thielow <ralf.thielow@gmail.com>
Acked-by: Thomas Rast <trast@inf.ethz.ch>
2013-05-07 19:28:19 +02:00
Nguyễn Thái Ngọc Duy
60003340cd clone: allow cloning local paths with colons in them
Usually "foo:bar" is interpreted as an ssh url. This patch allows to
clone from such paths by putting at least one slash before the colon
(i.e. /path/to/foo:bar or just ./foo:bar).

file://foo:bar should also work, but local optimizations are off in
that case, which may be unwanted. While at there, warn the users about
--local being ignored in this case.

Reported-by: William Giokas <1007380@gmail.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-07 08:32:14 -07:00
Felipe Contreras
47bd9bf82d fast-export: don't parse commits while reading marks file
We don't need the parsed objects at this point, merely the
information that they have marks.

Seems to be three times faster in my setup with lots of objects.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-07 07:03:01 -07:00
Felipe Contreras
e6812cfa9a fast-export: do not parse non-commit objects while reading marks file
We read from the marks file and keep only marked commits, but in
order to find the type of object, we are parsing the whole thing,
which is slow, specially in big repositories with lots of big files.

There's no need for that, we can query the object information with
sha1_object_info().

Before this, loading the objects of a fresh emacs import, with 260598
blobs took 14 minutes, after this patch, it takes 3 seconds.

This is the way fast-import does it. Also die if the object is not
found (like fast-import).

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-07 07:03:01 -07:00
Junio C Hamano
6f4dd60d07 deprecate core.statinfo at Git 2.0 boundary
c08e4d5b5c (Enable minimal stat checking, 2013-01-22) advertised
the configuration variable core.checkstat in the documentation and
its log message, but the code expected core.statinfo instead.

For now, add core.checkstat, and warn people who have core.statinfo
in their configuration file that we will remove it in Git 2.0.

Noticed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-06 22:31:42 -07:00
Junio C Hamano
423ecb0bb6 Merge branch 'jk/merge-tree-added-identically'
* jk/merge-tree-added-identically:
  merge-tree: handle directory/empty conflict correctly
2013-05-06 22:18:25 -07:00
John Keeping
94883b4302 merge-tree: handle directory/empty conflict correctly
git-merge-tree causes a null pointer dereference when a directory
entry exists in only one or two of the three trees being compared with
no corresponding entry in the other tree(s).

When this happens, we want to handle the entry as a directory and not
attempt to mark it as a file merge.  Do this by setting the entries bit
in the directory mask when the entry is missing or when it is a
directory, only performing the file comparison when we know that a file
entry exists.

Reported-by: Andreas Jacobsen <andreas@andreasjacobsen.com>
Signed-off-by: John Keeping <john@keeping.me.uk>
Tested-by: Andreas Jacobsen <andreas@andreasjacobsen.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-06 22:17:00 -07:00
Junio C Hamano
bba5367183 Merge branch 'fc/remote-bzr'
* fc/remote-bzr:
  remote-bzr: avoid bad refs
  remote-bzr: convert all unicode keys to str
  remote-bzr: access branches only when needed
  remote-bzr: delay peer branch usage
  remote-bzr: iterate revisions properly
  remote-bzr: improve progress reporting
  remote-bzr: add option to specify branches
  remote-bzr: add custom method to find branches
  remote-bzr: improve author sanitazion
  remote-bzr: add support for shared repo
  remote-bzr: fix branch names
  remote-bzr: add support for bzr repos
  remote-bzr: use branch variable when appropriate
  remote-bzr: fix partially pushed merge
  remote-bzr: fixes for branch diverge
  remote-bzr: add support to push merges
  remote-bzr: always try to update the worktree
  remote-bzr: fix order of locking in CustomTree
  remote-bzr: delay blob fetching until the very end
  remote-bzr: cleanup CustomTree
2013-05-06 22:16:26 -07:00
Felipe Contreras
4c00819910 remote-bzr: avoid bad refs
Versions of fast-export before v1.8.2 throws a bad 'reset' commands
because of a behavior in transport-helper that is not even needed.
We should ignore them, otherwise we will treat them as branches and
fail.

This was fixed in v1.8.2, but some people use this script in older
versions of git.

Also, check if the ref was a tag, and skip it for now.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-06 18:19:55 -07:00
Felipe Contreras
081811216e remote-bzr: convert all unicode keys to str
Otherwise some versions of bazaar might barf.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-06 09:18:52 -07:00
John Keeping
b3e0c4ed07 t/Makefile: don't define TEST_RESULTS_DIRECTORY recursively
Commit 54bb901 (t/Makefile: fix result handling with
TEST_OUTPUT_DIRECTORY - 2013-04-26) incorrectly defined
TEST_RESULTS_DIRECTORY relative to itself, when it should be relative to
TEST_OUTPUT_DIRECTORY.  Fix this.

Signed-off-by: John Keeping <john@keeping.me.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-06 08:20:28 -07:00
Junio C Hamano
2be2eb970c Merge branch 'fc/push-with-export-reporting-result'
* fc/push-with-export-reporting-result:
  transport-helper: improve push messages
2013-05-05 11:12:12 -07:00
Felipe Contreras
b056620f6f transport-helper: improve push messages
If there's already a remote-helper tracking ref, we can fetch the
SHA-1 to report proper push messages (as opposed to always reporting
[new branch]).

The remote-helper currently can specify the old SHA-1 to avoid this
problem, but there's no point in forcing all remote-helpers to be aware
of git commit ids; they should be able to be agnostic of them.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-05 11:10:53 -07:00
Junio C Hamano
7d3ccdffb5 Git 1.8.3-rc1
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-03 15:23:45 -07:00
Junio C Hamano
7c2e8fc684 Merge branch 'tr/unpack-entry-use-after-free-fix'
* tr/unpack-entry-use-after-free-fix:
  unpack_entry: avoid freeing objects in base cache
2013-05-03 15:18:04 -07:00
Junio C Hamano
1c937682c2 Sync with maint
* maint:
  completion: zsh: don't override suffix on _detault
  Documentation/git-commit: Typo under --edit
2013-05-03 15:17:38 -07:00
Junio C Hamano
571cdfd4e0 Merge branch 'tr/remote-tighten-commandline-parsing' into maint
* tr/remote-tighten-commandline-parsing:
  remote: 'show' and 'prune' can take more than one remote
  remote: check for superfluous arguments in 'git remote add'
  remote: add a test for extra arguments, according to docs
2013-05-03 15:12:38 -07:00
Junio C Hamano
49010c354f Merge branch 'jn/glossary-revision' into maint
* jn/glossary-revision:
  glossary: a revision is just a commit
2013-05-03 15:12:16 -07:00
Felipe Contreras
6606a69f45 completion: zsh: don't override suffix on _detault
zsh is smart enough to add the right suffix while completing, there's no
point in trying to do the same as bash.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-03 15:10:05 -07:00
Anders Granskogen Bjørnstad
9a3e36cd67 Documentation/git-commit: Typo under --edit
-C takes a commit object, not a file.

Signed-off-by: Anders Granskogen Bjørnstad <andersgb@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-02 12:03:40 -07:00
Michael Heemskerk
71d5f93891 t5500: add test for fetching with an unknown 'shallow'
When the client sends a 'shallow' line for an object that the server does
not have, the server should just ignore it and let the client keep that
unknown shallow boundary.

Signed-off-by: Michael Heemskerk <mheemskerk@atlassian.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-02 10:05:52 -07:00
Jeff King
9a414486d9 lookup_object: prioritize recently found objects
The lookup_object function is backed by a hash table of all
objects we have seen in the program. We manage collisions
with a linear walk over the colliding entries, checking each
with hashcmp(). The main cost of lookup is in these
hashcmp() calls; finding our item in the first slot is
cheaper than finding it in the second slot, which is cheaper
than the third, and so on.

If we assume that there is some locality to the object
lookups (e.g., if X and Y collide, and we have just looked
up X, the next lookup is more likely to be for X than for
Y), then we can improve our average lookup speed by checking
X before Y.

This patch does so by swapping a found item to the front of
the collision chain. The p0001 perf test reveals that this
does indeed exploit locality in the case of "rev-list --all
--objects":

Test                               origin          this tree
-------------------------------------------------------------------------
0001.1: rev-list --all             0.40(0.38+0.02) 0.40(0.36+0.03) +0.0%
0001.2: rev-list --all --objects   2.24(2.17+0.05) 1.86(1.79+0.05) -17.0%

This is not surprising, as the full object traversal will
hit the same tree entries over and over (e.g., for every
commit that doesn't change "Documentation/", we will have to
look up the same sha1 just to find out that we already
processed it).

The reason why this technique works (and does not violate
any properties of the hash table) is subtle and bears some
explanation. Let's imagine we get a lookup for sha1 `X`, and
it hashes to bucket `i` in our table. That stretch of the
table may look like:

index       | i-1 |  i  | i+1 | i+2 |
       -----------------------------------
entry   ... |  A  |  B  |  C  |  X  | ...
       -----------------------------------

We start our probe at i, see that B does not match, nor does
C, and finally find X. There may be multiple C's in the
middle, but we know that there are no empty slots (or else
we would not find X at all).

We do not know the original index of B; it may be `i`, or it
may be less than i (e.g., if it were `i-1`, it would collide
with A and spill over into the `i` bucket). So it is
acceptable for us to move it to the right of a contiguous
stretch of entries (because we will find it from a linear
walk starting anywhere at `i` or before), but never to the
left (if we moved it to `i-1`, we would miss it when
starting our walk at `i`).

We do know the original index of X; it is `i`, so it is safe
to place it anywhere in the contiguous stretch between `i`
and where we found it (`i+2` in the this case).

This patch does a pure swap; after finding X in the
situation above, we would end with:

index       | i-1 |  i  | i+1 | i+2 |
       -----------------------------------
entry   ... |  A  |  X  |  C  |  B  | ...
       -----------------------------------

We could instead bump X into the `i` slot, and then shift
the whole contiguous chain down by one, resulting in:

index       | i-1 |  i  | i+1 | i+2 |
       -----------------------------------
entry   ... |  A  |  X  |  B  |  C  | ...
       -----------------------------------

That puts our chain in true most-recently-used order.
However, experiments show that it is not any faster (and in
fact, is slightly slower due to the extra manipulation).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-02 08:36:50 -07:00
Michael Haggerty
9da31cb027 refs: handle the main ref_cache specially
Hold the ref_cache instance for the main repository in a dedicated,
statically-allocated instance to avoid the need for a function call
and a linked-list traversal when it is needed.

Suggested by: Heiko Voigt <hvoigt@hvoigt.net>

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-01 15:33:11 -07:00
Michael Haggerty
65cf102bb0 refs: change do_for_each_*() functions to take ref_cache arguments
Change the callers convert submodule names into ref_cache pointers.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-01 15:33:11 -07:00
Michael Haggerty
b2a8226d63 pack_one_ref(): do some cheap tests before a more expensive one
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-01 15:33:11 -07:00
Michael Haggerty
0f29920f1e pack_one_ref(): use write_packed_entry() to do the writing
Change pack_refs() to work with a file descriptor instead of a FILE*
(making the file-locking code less awkward) and use
write_packed_entry() to do the writing.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-01 15:33:11 -07:00
Michael Haggerty
f85354b5c7 pack_one_ref(): use function peel_entry()
Change pack_one_ref() to call peel_entry() rather than using its own
code for peeling references.  Aside from sharing code, this lets it
take advantage of the optimization introduced by 6c4a060d7d.

Please note that we *could* use any peeled values that happen to
already be stored in the ref_entries, which would avoid some object
lookups for references that were already packed.  But doing so would
also propagate any peeling errors across runs of "git pack-refs" and
give no way to recover from such errors.  And "git pack-refs" isn't
run often enough that the performance cost is a problem.  So instead,
add a new option to peel_entry() to force the entry to be re-peeled,
and call it with that option set.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-01 15:33:11 -07:00
Michael Haggerty
8d3725b96f refs: inline function do_not_prune()
Function do_not_prune() was redundantly checking REF_ISSYMREF, which
was already tested at the top of pack_one_ref(), so remove that check.
And the rest was trivial, so inline the function.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-01 15:33:11 -07:00