Commit Graph

149 Commits

Author SHA1 Message Date
Junio C Hamano
7b1004b0ba combine-diff: simplify intersect_paths() further
Linus once said:

    I actually wish more people understood the really core low-level
    kind of coding. Not big, complex stuff like the lockless name
    lookup, but simply good use of pointers-to-pointers etc. For
    example, I've seen too many people who delete a singly-linked
    list entry by keeping track of the "prev" entry, and then to
    delete the entry, doing something like

	if (prev)
	    prev->next = entry->next;
	else
	    list_head = entry->next;

    and whenever I see code like that, I just go "This person
    doesn't understand pointers". And it's sadly quite common.

    People who understand pointers just use a "pointer to the entry
    pointer", and initialize that with the address of the
    list_head. And then as they traverse the list, they can remove
    the entry without using any conditionals, by just doing a "*pp =
    entry->next".

Applying that simplification lets us lose 7 lines from this function
even while adding 2 lines of comment.

I was tempted to squash this into the original commit, but because
the benchmarking described in the commit log is without this
simplification, I decided to keep it a separate follow-up patch.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-02-24 14:44:57 -08:00
Kirill Smelkov
af82c7880f combine-diff: combine_diff_path.len is not needed anymore
The field was used in order to speed-up name comparison and also to
mark removed paths by setting it to 0.

Because the updated code does significantly less strcmp and also
just removes paths from the list and free right after we know a path
will not be needed, it is not needed anymore.

Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-02-24 14:44:57 -08:00
Kirill Smelkov
8518ff8fab combine-diff: optimize combine_diff_path sets intersection
When generating combined diff, for each commit, we intersect diff
paths from diff(parent_0,commit) to diff(parent_i,commit) comparing
all paths pairs, i.e. doing it the quadratic way. That is correct,
but could be optimized.

Paths come from trees in sorted (= tree) order, and so does diff_tree()
emits resulting paths in that order too. Now if we look at diffcore
transformations, all of them, except diffcore_order, preserve resulting
path ordering:

    - skip_stat_unmatch, grep, pickaxe, filter
                            -- just skip elements -> order stays preserved

    - break                 -- just breaks diff for a path, adding path
                               dup after the path -> order stays preserved

    - detect rename/copy    -- resulting paths are emitted sorted
                               (verified empirically)

So only diffcore_order changes diff paths ordering.

But diffcore_order meaning affects only presentation - i.e. only how to
show the diff, so we could do all the internal computations without
paths reordering, and order only resultant paths set. This is faster,
since, if we know two paths sets are all ordered, their intersection
could be done in linear time.

This patch does just that.

Timings for `git log --raw --no-abbrev --no-renames` without `-c` ("git log")
and with `-c` ("git log -c") before and after the patch are as follows:

                linux.git v3.10..v3.11

            log     log -c

    before  1.9s    20.4s
    after   1.9s    16.6s

                navy.git    (private repo)

            log     log -c

    before  0.83s   15.6s
    after   0.83s    2.1s

P.S.

I think linux.git case is sped up not so much as the second one, since
in navy.git, there are more exotic (subtree, etc) merges.

P.P.S.

My tracing showed that the rest of the time (16.6s vs 1.9s) is usually
spent in computing huge diffs from commit to second parent. Will try to
deal with it, if I'll have time.

P.P.P.S.

For combine_diff_path, ->len is not needed anymore - will remove it in
the next noisy cleanup path, to maintain good signal/noise ratio here.

Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-02-24 14:44:57 -08:00
Junio C Hamano
b02f5aeda6 Merge branch 'jl/submodule-mv'
"git mv A B" when moving a submodule A does "the right thing",
inclusing relocating its working tree and adjusting the paths in
the .gitmodules file.

* jl/submodule-mv: (53 commits)
  rm: delete .gitmodules entry of submodules removed from the work tree
  mv: update the path entry in .gitmodules for moved submodules
  submodule.c: add .gitmodules staging helper functions
  mv: move submodules using a gitfile
  mv: move submodules together with their work trees
  rm: do not set a variable twice without intermediate reading.
  t6131 - skip tests if on case-insensitive file system
  parse_pathspec: accept :(icase)path syntax
  pathspec: support :(glob) syntax
  pathspec: make --literal-pathspecs disable pathspec magic
  pathspec: support :(literal) syntax for noglob pathspec
  kill limit_pathspec_to_literal() as it's only used by parse_pathspec()
  parse_pathspec: preserve prefix length via PATHSPEC_PREFIX_ORIGIN
  parse_pathspec: make sure the prefix part is wildcard-free
  rename field "raw" to "_raw" in struct pathspec
  tree-diff: remove the use of pathspec's raw[] in follow-rename codepath
  remove match_pathspec() in favor of match_pathspec_depth()
  remove init_pathspec() in favor of parse_pathspec()
  remove diff_tree_{setup,release}_paths
  convert common_prefix() to use struct pathspec
  ...
2013-09-09 14:36:15 -07:00
Junio C Hamano
4ab4a6dfb4 Merge branch 'tr/log-full-diff-keep-true-parents'
Output from "git log --full-diff -- <pathspec>" looked strange,
because comparison was done with the previous ancestor that touched
the specified <pathspec>, causing the patches for paths outside the
pathspec to show more than the single commit has changed.

Tweak "git reflog -p" for the same reason using the same mechanism.

* tr/log-full-diff-keep-true-parents:
  log: use true parents for diff when walking reflogs
  log: use true parents for diff even when rewriting
2013-09-09 14:33:16 -07:00
Thomas Rast
53d00b39ce log: use true parents for diff even when rewriting
When using pathspec filtering in combination with diff-based log
output, parent simplification happens before the diff is computed.
The diff is therefore against the *simplified* parents.

This works okay, arguably by accident, in the normal case:
simplification reduces to one parent as long as the commit is TREESAME
to it.  So the simplified parent of any given commit must have the
same tree contents on the filtered paths as its true (unfiltered)
parent.

However, --full-diff breaks this guarantee, and indeed gives pretty
spectacular results when comparing the output of

  git log --graph --stat ...
  git log --graph --full-diff --stat ...

(--graph internally kicks in parent simplification, much like
--parents).

To fix it, store a copy of the parent list before simplification (in a
slab) whenever --full-diff is in effect.  Then use the stored parents
instead of the simplified ones in the commit display code paths.  The
latter do not actually check for --full-diff to avoid duplicated code;
they just grab the original parents if save_parents() has not been
called for this revision walk.

For ordinary commits it should be obvious that this is the right thing
to do.

Merge commits are a bit subtle.  Observe that with default
simplification, merge simplification is an all-or-nothing decision:
either the merge is TREESAME to one parent and disappears, or it is
different from all parents and the parent list remains intact.
Redundant parents are not pruned, so the existing code also shows them
as a merge.

So if we do show a merge commit, the parent list just consists of the
rewrite result on each parent.  Running, e.g., --cc on this in
--full-diff mode is not very useful: if any commits were skipped, some
hunks will disagree with all sides of the merge (with one side,
because commits were skipped; with the others, because they didn't
have those changes in the first place).  This triggers --cc showing
these hunks spuriously.

Therefore I believe that even for merge commits it is better to show
the diffs wrt. the original parents.

Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Helped-by: Junio C Hamano <gitster@pobox.com>
Helped-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Signed-off-by: Thomas Rast <trast@inf.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-08-01 10:25:48 -07:00
Ondřej Bílka
98e023dea4 many small typofixes
Signed-off-by: Ondřej Bílka <neleai@seznam.cz>
Reviewed-by: Marc Branchaud <marcnarc@xiplink.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-07-29 12:32:25 -07:00
Nguyễn Thái Ngọc Duy
bd1928df1d remove diff_tree_{setup,release}_paths
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-07-15 10:56:09 -07:00
Junio C Hamano
a1ddd11452 Merge branch 'cb/log-follow-with-combined'
* cb/log-follow-with-combined:
  fix segfault with git log -c --follow
2013-06-11 13:30:36 -07:00
Junio C Hamano
edc7f0abcb Merge branch 'mk/combine-diff-context-horizon-fix'
"git diff -c -p" was not showing a deleted line from a hunk when
another hunk immediately begins where the earlier one ends.

* mk/combine-diff-context-horizon-fix:
  combine-diff.c: Fix output when changes are exactly 3 lines apart
2013-06-02 15:56:46 -07:00
Clemens Buchacher
46ec510ac0 fix segfault with git log -c --follow
In diff_tree_combined we make a copy of diffopts. In
try_to_follow_renames, called via diff_tree_sha1, we free and
re-initialize diffopts->pathspec->items. Since we did not make a deep
copy of diffopts in diff_tree_combined, the original diffopts does not
get the update. By the time we return from diff_tree_combined,
rev->diffopt->pathspec->items points to an invalid memory address. We
get a segfault next time we try to access that pathspec.

Instead, along with the copy of diffopts, make a copy pathspec->items as
well.

We would also have to make a copy of pathspec->raw to keep it consistent
with pathspec->items, but nobody seems to rely on that.

Signed-off-by: Clemens Buchacher <drizzd@aon.at>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-28 11:26:24 -07:00
Matthijs Kooijman
aac385717a combine-diff.c: Fix output when changes are exactly 3 lines apart
When a deletion is followed by exactly 3 (or whatever the number of
context lines) unchanged lines, followed by another change, the combined
diff output would hide the first deletion, resulting in a malformed
diff.

This happened because the 3 lines before each change are painted
interesting, but also marked as no_pre_delete to prevent showing deletes
that were previously marked as uninteresting. This behaviour was
introduced in c86fbe53 (diff -c/--cc: do not include uninteresting
deletion before leading context). However, as a side effect, this could
also mark deletes that were already interesting as no_pre_delete. This
would happen only if the delete was exactly 3 lines away from the next
change, since lines farther away would not be touched by the "paint
three lines before the change" code and lines closer would be painted
by the "merge two adjacent hunks" code instead, which does not set the
no_pre_delete flag.

This commit fixes this problem by only setting the no_pre_delete flag
for changes that were previously uninteresting.

Signed-off-by: Matthijs Kooijman <matthijs@stdin.nl>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-15 12:02:04 -07:00
Antoine Pelisse
99d3206010 combine-diff: coalesce lost lines optimally
This replaces the greedy implementation to coalesce lost lines by using
dynamic programming to find the Longest Common Subsequence.

The O(n²) time complexity is obviously bigger than previous
implementation but it can produce shorter diff results (and most likely
easier to read).

List of lost lines is now doubly-linked because we reverse-read it when
reading the direction matrix.

Signed-off-by: Antoine Pelisse <apelisse@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-03-25 14:52:33 -07:00
Antoine Pelisse
fa04ae0be8 Allow combined diff to ignore white-spaces
The combined diff --cc output does not honor options to ignore
whitespace changes (-b, -w, and --ignore-space-at-eol).

Correct this by passing diff flags to diff engine, so that combined
diff behaves as normal diff does with spaces, and by coalescing
lines that are removed from both (or more) parents, honoring the
same rule to ignore whitespace changes.

With this change, a conflict-less merge done using a ignore-*
strategy option will not show any conflict if shown in combined-diff
using the same option.

Signed-off-by: Antoine Pelisse <apelisse@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-03-14 14:43:34 -07:00
Junio C Hamano
a1d68bea89 Merge branch 'jk/diff-graph-cleanup'
Refactors a lot of repetitive code sequence from the graph drawing
code and adds it to the combined diff output.

* jk/diff-graph-cleanup:
  combine-diff.c: teach combined diffs about line prefix
  diff.c: use diff_line_prefix() where applicable
  diff: add diff_line_prefix function
  diff.c: make constant string arguments const
  diff: write prefix to the correct file
  graph: output padding for merge subsequent parents
2013-02-14 10:29:59 -08:00
John Keeping
41ee2ad6cb combine-diff.c: teach combined diffs about line prefix
When running "git log --graph --cc -p" the diff output for merges is not
indented by the graph structure, unlike the diffs of non-merge commits
(added in commit 7be5761 - diff.c: Output the text graph padding before
each diff line).

Fix this by teaching the combined diff code to output diff_line_prefix()
before each line.

Signed-off-by: John Keeping <john@keeping.me.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-12 11:42:07 -08:00
Junio C Hamano
7766705198 combine-diff: lift 32-way limit of combined diff
The "raw" format of combine-diff output is supposed to have as many
colons as there are parents at the beginning, then blob modes for
these parents, and then object names for these parents.

We weren't however prepared to handle a more than 32-way merge and
did not show the correct number of colons in such a case.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-03 13:08:18 -08:00
Junio C Hamano
03adeeaad6 Merge branch 'jk/maint-null-in-trees' into maint-1.7.11
"git diff" had a confusion between taking data from a path in the
working tree and taking data from an object that happens to have
name 0{40} recorded in a tree.

* jk/maint-null-in-trees:
  fsck: detect null sha1 in tree entries
  do not write null sha1s to on-disk index
  diff: do not use null sha1 as a sentinel value
2012-09-10 15:24:54 -07:00
Junio C Hamano
3b753148b6 Merge branch 'jk/maint-null-in-trees'
We do not want a link to 0{40} object stored anywhere in our objects.

* jk/maint-null-in-trees:
  fsck: detect null sha1 in tree entries
  do not write null sha1s to on-disk index
  diff: do not use null sha1 as a sentinel value
2012-08-27 11:54:28 -07:00
Jeff King
e54501004a diff: do not use null sha1 as a sentinel value
The diff code represents paths using the diff_filespec
struct. This struct has a sha1 to represent the sha1 of the
content at that path, as well as a sha1_valid member which
indicates whether its sha1 field is actually useful. If
sha1_valid is not true, then the filespec represents a
working tree file (e.g., for the no-index case, or for when
the index is not up-to-date).

The diff_filespec is only used internally, though. At the
interfaces to the diff subsystem, callers feed the sha1
directly, and we create a diff_filespec from it. It's at
that point that we look at the sha1 and decide whether it is
valid or not; callers may pass the null sha1 as a sentinel
value to indicate that it is not.

We should not typically see the null sha1 coming from any
other source (e.g., in the index itself, or from a tree).
However, a corrupt tree might have a null sha1, which would
cause "diff --patch" to accidentally diff the working tree
version of a file instead of treating it as a blob.

This patch extends the edges of the diff interface to accept
a "sha1_valid" flag whenever we accept a sha1, and to use
that flag when creating a filespec. In some cases, this
means passing the flag through several layers, making the
code change larger than would be desirable.

One alternative would be to simply die() upon seeing
corrupted trees with null sha1s. However, this fix more
directly addresses the problem (while bogus sha1s in a tree
are probably a bad thing, it is really the sentinel
confusion sending us down the wrong code path that is what
makes it devastating). And it means that git is more capable
of examining and debugging these corrupted trees. For
example, you can still "diff --raw" such a tree to find out
when the bogus entry was introduced; you just cannot do a
"--patch" diff (just as you could not with any other
corrupted tree, as we do not have any content to diff).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-07-29 15:04:32 -07:00
Junio C Hamano
f84e8b6069 Merge branch 'rs/combine-diff-zero-context-at-the-beginning'
Fixes an age old corner case bug in combine diff (only triggered with -U0
and the hunk at the beginning of the file needs to be shown).

By René Scharfe
* rs/combine-diff-zero-context-at-the-beginning:
  combine-diff: fix loop index underflow
2012-04-16 12:41:59 -07:00
René Scharfe
e5e9b56528 combine-diff: fix loop index underflow
If both la and context are zero at the start of the loop, la wraps around
and we end up reading from memory far away.  Skip the loop in that case
instead.

Reported-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-03-25 21:35:52 -07:00
René Scharfe
82889295e7 pass struct commit to diff_tree_combined_merge()
Instead of passing the hash of a commit and then searching that
same commit in the single caller, simply pass the commit directly.

Signed-off-by: René Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-12-17 18:22:29 -08:00
René Scharfe
0041f09de6 use struct sha1_array in diff_tree_combined()
Maintaining an array of hashes is easier using sha1_array than
open-coding it.  This patch also fixes a leak of the SHA1 array
in  diff_tree_combined_merge().

Signed-off-by: René Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-12-17 18:21:37 -08:00
Junio C Hamano
f946b465d7 Merge branch 'jk/color-and-pager'
* jk/color-and-pager:
  want_color: automatically fallback to color.ui
  diff: don't load color config in plumbing
  config: refactor get_colorbool function
  color: delay auto-color decision until point of use
  git_config_colorbool: refactor stdout_is_tty handling
  diff: refactor COLOR_DIFF from a flag into an int
  setup_pager: set GIT_PAGER_IN_USE
  t7006: use test_config helpers
  test-lib: add helper functions for config
  t7006: modernize calls to unset

Conflicts:
	builtin/commit.c
	parse-options.c
2011-08-28 21:19:16 -07:00
Junio C Hamano
e78f829143 Merge branch 'jc/combine-diff-callback'
* jc/combine-diff-callback:
  combine-diff: support format_callback
2011-08-28 21:15:33 -07:00
Junio C Hamano
25e5e2bf85 combine-diff: support format_callback
This teaches combine-diff machinery to feed a combined merge to a callback
function when DIFF_FORMAT_CALLBACK is specified.

So far, format callback functions are not used for anything but 2-way
diffs. A callback is given a diff_queue_struct, which is an array of
diff_filepair. As its name suggests, a diff_filepair is a _pair_ of
diff_filespec that represents a single preimage and a single postimage.

Since "diff -c" is to compare N parents with a single merge result and
filter out any paths whose result match one (or more) of the parent(s),
its output has to be able to represent N preimages and 1 postimage. For
this reason, a callback function that inspects a diff_filepair that
results from this new infrastructure can and is expected to view the
preimage side (i.e. pair->one) as an array of diff_filespec. Each element
in the array, except for the last one, is marked with "has_more_entries"
bit, so that the same callback function can be used for 2-way diffs and
combined diffs.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-08-20 23:03:06 -07:00
Jeff King
f1c9626105 diff: refactor COLOR_DIFF from a flag into an int
This lets us store more than just a bit flag for whether we
want color; we can also store whether we want automatic
colors. This can be useful for making the automatic-color
decision closer to the point of use.

This mostly just involves replacing DIFF_OPT_* calls with
manipulations of the flag. The biggest exception is that
calls to DIFF_OPT_TST must check for "o->use_color > 0",
which lets an "unknown" value (i.e., the default) stay at
"no color". In the previous code, a value of "-1" was not
propagated at all.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-08-18 14:35:53 -07:00
Junio C Hamano
660578d4da Merge branch 'jc/maint-combined-diff-work-tree'
* jc/maint-combined-diff-work-tree:
  diff -c/--cc: do not mistake "resolved as deletion" as "use working tree"

Conflicts:
	combine-diff.c
2011-08-17 17:25:59 -07:00
Junio C Hamano
9969454435 diff -c/--cc: do not mistake "resolved as deletion" as "use working tree"
The combined diff machinery can be used to compare:

 - a merge commit with its parent commits;
 - a working-tree file with multiple stages in an unmerged index; or
 - a working-tree file with the HEAD and the index.

The internal function combine-diff.c:show_patch_diff() checked if it needs
to read the "result" from the working tree by looking at the object name
of the result --- if it is null_sha1, it read from the working tree.

This mistook a merge that records a deletion as the conflict resolution
as if it is a cue to read from the working tree. Pass this information
explicitly from the caller instead.

Noticed and reported by Johan Herland.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-08-04 12:05:47 -07:00
Jeff King
0508fe533d combine-diff: respect textconv attributes
When doing a combined diff, we did not respect textconv attributes at
all. This generally lead to us printing "Binary files differ" when we
could show a combined diff of the converted text.

This patch converts file contents according to textconv attributes. The
implementation is slightly ugly; because the textconv code is tightly
linked with the diff_filespec code, we temporarily create a diff_filespec
during conversion. In practice, though, this should not create a
performance problem.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-05-24 09:08:17 -07:00
Jeff King
4d5f347199 combine-diff: handle binary files as binary
The combined diff code path is totally different from the
regular diff code path, and didn't handle binary files at
all. The results of a combined diff on a binary file could
range from annoying (since we spewed binary garbage,
possibly upsetting the user's terminal), to wrong (embedded
NULs caused us to show incorrect diffs, with lines truncated
at the NUL character), to potential security problems
(embedded NULs could interfere with "-z" output, possibly
defeating policy hooks which parse diff output).

Instead, we consider a combined diff to be binary if any of
the input blobs is binary. To show a binary combined diff,
we indicate "Binary blobs differ"; the "index" meta line
will show which parents had which blob.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-05-23 15:43:43 -07:00
Jeff King
c95b99bb5d combine-diff: calculate mode_differs earlier
One loop combined both the patch generation and checking
whether there was any mode change to report. Let's factor
that into two separate loops, as we may care about the mode
change even if we are not generating patches (e.g., because
we are showing a binary diff, which will come in a future
patch).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-05-23 15:40:51 -07:00
Jeff King
7c978a068f combine-diff: split header printing into its own function
This is a pretty big logical chunk, so it makes the function
a bit more readable to have it split out. In addition, it
will make it easier to add an alternate code path for binary
diffs in a future patch.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-05-23 15:39:33 -07:00
Junio C Hamano
60335534a6 Merge branch 'rs/diff-no-minimal' into maint
* rs/diff-no-minimal:
  git diff too slow for a file
2010-06-21 05:38:50 -07:00
Junio C Hamano
39b5977b13 Merge branch 'rs/diff-no-minimal'
* rs/diff-no-minimal:
  git diff too slow for a file
2010-06-13 11:20:46 -07:00
René Scharfe
dfea79004c remove ecb parameter from xdi_diff_outf()
xdi_diff_outf() overrides the structure members of its last parameter,
ignoring any value that callers pass in.  It's no surprise then that all
callers pass a pointer to an uninitialized structure.  They also don't
read it after the call, so the parameter is neither used for input nor
for output.   Turn it into a local variable of xdi_diff_outf().

Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-05-04 15:19:14 -07:00
René Scharfe
582aa00bdf git diff too slow for a file
Ever since the xdiff library had been introduced to git, all its callers
have used the flag XDF_NEED_MINIMAL.  It makes sure that the smallest
possible diff is produced, but that takes quite some time if there are
lots of differences that can be expressed in multiple ways.

This flag makes a difference for only 0.1% of the non-merge commits in
the git repo of Linux, both in terms of diff size and execution time.
The patches there are mostly nice and small.

SungHyun Nam however reported a case in a different repo where a diff
took more than 20 times longer to generate with XDF_NEED_MINIMAL than
without.  Rebasing became really slow.

This patch removes this flag from all callers.  The default of xdiff is
saner because it has minimal to no impact in the normal case of small
diffs and doesn't incur that much of a speed penalty for large ones.

A follow-up patch may introduce a command line option to set the flag if
the user needs it, similar to GNU diff's -d/--minimal.

Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-05-02 07:59:50 -07:00
Thomas Rast
2179870803 combined diff: correctly handle truncated file
Consider an evil merge of two commits A and B, both of which have a
file 'foo', but the merge result does not have that file.

The combined-diff code learned in 4462731 (combine-diff: do not punt
on removed or added files., 2006-02-06) to concisely show only the
removal, since that is the evil part and the previous contents are
presumably uninteresting.

However, to diagnose an empty merge result, it overloaded the variable
that holds the file's length.  This means that the check also triggers
for truncated files.  Consequently, such files were not shown in the
diff at all despite the merge being clearly evil.

Fix this by adding a new variable that distinguishes whether the file
was deleted (which is the case 4462731 handled) or truncated.  In the
truncated case, we show the full combined diff again, which is rather
spammy but at least does not hide the evilness.

Reported-by: David Martínez Martí <desarrollo@gestiweb.com>
Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-04-17 10:23:59 -07:00
Bert Wesarg
89cb73a19a Give the hunk comment its own color
Inspired by the coloring of quilt.

Introduce a separate color and paint the hunk comment part, i.e. the name
of the function, in a separate color "diff.func" (defaults to plain).

Whitespace between hunk header and hunk comment is printed in plain color.

Signed-off-by: Bert Wesarg <bert.wesarg@googlemail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-11-28 10:05:44 -08:00
Junio C Hamano
248b6c0609 Merge branch 'maint'
* maint:
  Trailing whitespace and no newline fix
  diff --cc: a lost line at the beginning of the file is shown incorrectly
  combine-diff.c: fix performance problem when folding common deleted lines
2009-07-22 21:56:46 -07:00
Junio C Hamano
b810cbbde9 diff --cc: a lost line at the beginning of the file is shown incorrectly
When combine-diff inspected the diff from one parent to the merge result,
it misinterpreted a header in the form @@ -l,k +0,0 @@.

This hunk header means that K lines were removed from the beginning of the
file, so the lost lines must be queued to the sline that represents the
first line of the merge result, but we incremented our pointer incorrectly
and ended up queuing it to the second line, which in turn made the lossage
appear _after_ the first line.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-07-22 15:38:22 -07:00
Junio C Hamano
55d5d5bab7 combine-diff.c: fix performance problem when folding common deleted lines
For a deleted line in a patch with the parent we are looking at, the
append_lost() function finds the same line among a run of lines that were
deleted from the same location by patches from parents we previously
checked.  This is so that patches with two parents

    @@ -1,4 +1,3 @@    @@ -1,4 +1,3 @@
     one                   one
    -two                  -two
     three                 three
    -quatro               -fyra
    +four                 +four

can be coalesced into this sequence, reusing one line that describes the
removal of "two" for both parents.

   @@@ -1,4 -1,4 +1,3 @@@
     one
   --two
     three
   - quatro
    -frya
   ++four

While reading the second patch (that removes "two" and then "fyra"), after
finding where removal of the "two" matches, we need to find existing
removal of "fyra" (if exists) in the removal list, but the match has to
happen after all the existing matches (in this case "two").  The code used
a naïve O(n^2) algorithm to compute this by scanning the whole removal
list over and over again.

This patch remembers where the next scan should be started in the existing
removal list to avoid this.

Noticed by Linus Torvalds.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-07-22 15:37:55 -07:00
Thomas Rast
0721c314a5 Use die_errno() instead of die() when checking syscalls
Lots of die() calls did not actually report the kind of error, which
can leave the user confused as to the real problem.  Use die_errno()
where we check a system/library call that sets errno on failure, or
one of the following that wrap such calls:

  Function              Passes on error from
  --------              --------------------
  odb_pack_keep         open
  read_ancestry         fopen
  read_in_full          xread
  strbuf_read           xread
  strbuf_read_file      open or strbuf_read_file
  strbuf_readlink       readlink
  write_in_full         xwrite

Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-06-27 11:14:53 -07:00
Felipe Contreras
4b25d091ba Fix a bunch of pointer declarations (codestyle)
Essentially; s/type* /type */ as per the coding guidelines.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-05-01 15:17:31 -07:00
Junio C Hamano
d1c8c0c8c4 Merge branch 'maint'
* maint:
  diff -c -p: do not die on submodules

Conflicts:
	combine-diff.c
2009-04-29 16:50:31 -07:00
Junio C Hamano
934747323c Merge branch 'maint-1.6.0' into maint-1.6.1
* maint-1.6.0:
  diff -c -p: do not die on submodules
2009-04-29 13:43:13 -07:00
Junio C Hamano
7dae8b21c2 diff -c -p: do not die on submodules
The combine diff logic knew only about blobs (and their checked-out form
in the work tree, either regular files or symlinks), and barfed when fed
submodules.  This "externalizes" gitlinks in the same way as the normal
patch generation codepath does (i.e. "Subproject commit Xxx\n") to fix the
issue.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-04-29 12:49:52 -07:00
Junio C Hamano
a9bfe81309 Merge branch 'kb/checkout-optim'
* kb/checkout-optim:
  Revert "lstat_cache(): print a warning if doing ping-pong between cache types"
  checkout bugfix: use stat.mtime instead of stat.ctime in two places
  Makefile: Set compiler switch for USE_NSEC
  Create USE_ST_TIMESPEC and turn it on for Darwin
  Not all systems use st_[cm]tim field for ns resolution file timestamp
  Record ns-timestamps if possible, but do not use it without USE_NSEC
  write_index(): update index_state->timestamp after flushing to disk
  verify_uptodate(): add ce_uptodate(ce) test
  make USE_NSEC work as expected
  fix compile error when USE_NSEC is defined
  check_updates(): effective removal of cache entries marked CE_REMOVE
  lstat_cache(): print a warning if doing ping-pong between cache types
  show_patch_diff(): remove a call to fstat()
  write_entry(): use fstat() instead of lstat() when file is open
  write_entry(): cleanup of some duplicated code
  create_directories(): remove some memcpy() and strchr() calls
  unlink_entry(): introduce schedule_dir_for_removal()
  lstat_cache(): swap func(length, string) into func(string, length)
  lstat_cache(): generalise longest_match_lstat_cache()
  lstat_cache(): small cleanup and optimisation
2009-03-17 18:54:31 -07:00
Benjamin Kramer
fd13b21f52 Move local variables to narrower scopes
These weren't used outside and can be safely moved

Signed-off-by: Benjamin Kramer <benny.kra@googlemail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-03-07 20:52:23 -08:00