"git diff --diff-filter=aR" is now parsed correctly.
* js/diff-filter-negation-fix:
diff-filter: be more careful when looking for negative bits
diff.c: move the diff filter bits definitions up a bit
docs(diff): lose incorrect claim about `diff-files --diff-filter=A`
"git log --remerge-diff" shows the difference from mechanical merge
result and the result that is actually recorded in a merge commit.
* en/remerge-diff:
diff-merges: avoid history simplifications when diffing merges
merge-ort: mark conflict/warning messages from inner merges as omittable
show, log: include conflict/warning messages in --remerge-diff headers
diff: add ability to insert additional headers for paths
merge-ort: format messages slightly different for use in headers
merge-ort: mark a few more conflict messages as omittable
merge-ort: capture and print ll-merge warnings in our preferred fashion
ll-merge: make callers responsible for showing warnings
log: clean unneeded objects during `log --remerge-diff`
show, log: provide a --remerge-diff capability
The "struct option" added in 4a28847839 (diff.c: prepare to use
parse_options() for parsing, 2019-01-27) would be free'd in the case
of diff_setup_done() being called.
But not all codepaths that allocate it reach that,
e.g. "t6427-diff3-conflict-markers.sh" will now free memory that it
didn't free before. By using FREE_AND_NULL() here (which
diff_setup_done() also does) we ensure that we free the memory, and
that we won't have double-free's.
Before this running:
./t6427-diff3-conflict-markers.sh -vixd --run=7
Would report:
SUMMARY: LeakSanitizer: 7823 byte(s) leaked in 6 allocation(s).
But now we'll report:
SUMMARY: LeakSanitizer: 703 byte(s) leaked in 5 allocation(s).
I.e. the largest leak in that particular test has now been addressed.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Have the diff_free() function call clear_pathspec(). Since the
diff_flush() function calls this all its callers can be simplified to
rely on it instead.
When I added the diff_free() function in e900d494dc (diff: add an API
for deferred freeing, 2021-02-11) I simply missed this, or wasn't
interested in it. Let's consolidate this now. This means that any
future callers (and I've got revision.c in mind) that embed a "struct
diff_options" can simply call diff_free() instead of needing know that
it has an embedded pathspec.
This does fix a bunch of leaks, but I can't mark any test here as
passing under the SANITIZE=leak testing mode because in
886e1084d7 (builtin/: add UNLEAKs, 2017-10-01) an UNLEAK(rev) was
added, which plasters over the memory
leak. E.g. "t4011-diff-symlink.sh" would report fewer leaks with this
fix, but because of the UNLEAK() reports none.
I'll eventually loop around to removing that UNLEAK(rev) annotation as
I'll fix deeper issues with the revisions API leaking. This is one
small step on the way there, a new freeing function in revisions.c
will want to call this diff_free().
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When additional headers are provided, we need to
* add diff_filepairs to diff_queued_diff for each paths in the
additional headers map which, unless that path is part of
another diff_filepair already found in diff_queued_diff
* format the headers (colorization, line_prefix for --graph)
* make sure the various codepaths that attempt to return early
if there are "no changes" take into account the headers that
need to be shown.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `--diff-filter=<bits>` option allows to filter the diff by certain
criteria, for example `R` to only show renamed files. It also supports
negating a filter via a down-cased letter, i.e. `r` to show _everything
but_ renamed files.
However, the code is a bit overzealous when trying to figure out whether
`git diff` should start with all diff-filters turned on because the user
provided a lower-case letter: if the `--diff-filter` argument starts
with an upper-case letter, we must not start with all bits turned on.
Even worse, it is possible to specify the diff filters in multiple,
separate options, e.g. `--diff-filter=AM [...] --diff-filter=m`.
Let's accumulate the include/exclude filters independently, and only
special-case the "only exclude filters were specified" case after
parsing the options altogether.
Note: The code replaced by this commit took pains to avoid setting any
unused bits of `options->filter`. That was unnecessary, though, as all
accesses happen via the `filter_bit_tst()` function using specific bits,
and setting the unused bits has no effect. Therefore, we can simplify
the code by using `~0` (or in this instance, `~<unwanted-bit>`).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This prepares for a more careful handling of the `--diff-filter`
options over the next few commits.
This commit is best viewed with `--color-moved`.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Similar message templates have been consolidated so that
translators need to work on fewer number of messages.
* ja/i18n-similar-messages:
i18n: turn even more messages into "cannot be used together" ones
i18n: ref-filter: factorize "%(foo) atom used without %(bar) atom"
i18n: factorize "--foo outside a repository"
i18n: refactor "unrecognized %(foo) argument" strings
i18n: factorize "no directory given for --foo"
i18n: factorize "--foo requires --bar" and the like
i18n: tag.c factorize i18n strings
i18n: standardize "cannot open" and "cannot read"
i18n: turn "options are incompatible" into "cannot be used together"
i18n: refactor "%s, %s and %s are mutually exclusive"
i18n: refactor "foo and bar are mutually exclusive"
Correctness and performance update to "diff --color-moved" feature.
* pw/diff-color-moved-fix:
diff --color-moved: intern strings
diff: use designated initializers for emitted_diff_symbol
diff --color-moved-ws=allow-indentation-change: improve hash lookups
diff --color-moved: stop clearing potential moved blocks
diff --color-moved: shrink potential moved blocks as we go
diff --color-moved: unify moved block growth functions
diff --color-moved: call comparison function directly
diff --color-moved-ws=allow-indentation-change: simplify and optimize
diff: simplify allow-indentation-change delta calculation
diff --color-moved: avoid false short line matches and bad zebra coloring
diff --color-moved=zebra: fix alternate coloring
diff --color-moved: rewind when discarding pmb
diff --color-moved: factor out function
diff --color-moved: clear all flags on blocks that are too short
diff --color-moved: add perf tests
Even if some of these messages are not subject to gettext i18n, this
helps bring a single style of message for a given error type.
Signed-off-by: Jean-Noël Avila <jn.avila@free.fr>
Reviewed-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use placeholders for constant tokens. The strings are turned into
"cannot be used together"
Signed-off-by: Jean-Noël Avila <jn.avila@free.fr>
Reviewed-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Taking inspiration from xdl_classify_record() assign an id to each
addition and deletion such that lines that match for the current
--color-moved-ws mode share the same unique id. This reduces the
number of hash lookups a little (calculating the ids still involves
one hash lookup per line) but the main benefit is that when growing
blocks of potentially moved lines we can replace string comparisons
which involve chasing a pointer with a simple integer comparison. On a
large diff this commit reduces the time to run 'diff --color-moved' by
37% compared to the previous commit and 31% compared to master, for
'diff --color-moved-ws=allow-indentation-change' the reduction is 28%
compared to the previous commit and 96% compared to master. There is
little change in the performance of 'git log --patch' as the diffs are
smaller.
Test HEAD^ HEAD
---------------------------------------------------------------------------------------------------------------
4002.1: diff --no-color-moved --no-color-moved-ws large change 0.38(0.33+0.05) 0.38(0.33+0.05) +0.0%
4002.2: diff --color-moved --no-color-moved-ws large change 0.88(0.81+0.06) 0.55(0.50+0.04) -37.5%
4002.3: diff --color-moved-ws=allow-indentation-change large change 0.85(0.79+0.06) 0.61(0.54+0.06) -28.2%
4002.4: log --no-color-moved --no-color-moved-ws 1.16(1.07+0.08) 1.15(1.09+0.05) -0.9%
4002.5: log --color-moved --no-color-moved-ws 1.31(1.22+0.08) 1.29(1.19+0.09) -1.5%
4002.6: log --color-moved-ws=allow-indentation-change 1.32(1.24+0.08) 1.31(1.18+0.13) -0.8%
Test master HEAD
---------------------------------------------------------------------------------------------------------------
4002.1: diff --no-color-moved --no-color-moved-ws large change 0.38 (0.33+0.05) 0.38(0.33+0.05) +0.0%
4002.2: diff --color-moved --no-color-moved-ws large change 0.80 (0.75+0.04) 0.55(0.50+0.04) -31.2%
4002.3: diff --color-moved-ws=allow-indentation-change large change 14.20(14.15+0.05) 0.61(0.54+0.06) -95.7%
4002.4: log --no-color-moved --no-color-moved-ws 1.15 (1.05+0.09) 1.15(1.09+0.05) +0.0%
4002.5: log --color-moved --no-color-moved-ws 1.30 (1.19+0.11) 1.29(1.19+0.09) -0.8%
4002.6: log --color-moved-ws=allow-indentation-change 1.70 (1.63+0.06) 1.31(1.18+0.13) -22.9%
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This makes it clearer which fields are being explicitly initialized
and will simplify the next commit where we add a new field to the
struct.
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
As libxdiff does not have a whitespace flag to ignore the indentation
the code for --color-moved-ws=allow-indentation-change uses
XDF_IGNORE_WHITESPACE and then filters out any hash lookups where
there are non-indentation changes. This filtering is inefficient as
we have to perform another string comparison.
By using the offset data that we have already computed to skip the
indentation we can avoid using XDF_IGNORE_WHITESPACE and safely remove
the extra checks which improves the performance by 11% and paves the
way for the elimination of string comparisons in the next commit.
This change slightly increases the run time of other --color-moved
modes. This could be avoided by using different comparison functions
for the different modes but after the next two commits there is no
measurable benefit in doing so.
There is a change in behavior for lines that begin with a form-feed or
vertical-tab character. Since b46054b374 ("xdiff: use
git-compat-util", 2019-04-11) xdiff does not treat '\f' or '\v' as
whitespace characters. This means that lines starting with those
characters are never considered to be blank and never match a line
that does not start with the same character. After this patch a line
matching "^[\f\v\r]*[ \t]*$" is considered to be blank by
--color-moved-ws=allow-indentation-change and lines beginning
"^[\f\v\r]*[ \t]*" can match another line if the suffixes match. This
changes the output of git show for d18f76dccf ("compat/regex: use the
regex engine from gawk for compat", 2010-08-17) as some lines in the
pre-image before a moved block that contain '\f' are now considered
moved as well as they match a blank line before the moved lines in the
post-image. This commit updates one of the tests to reflect this
change.
Test HEAD^ HEAD
--------------------------------------------------------------------------------------------------------------
4002.1: diff --no-color-moved --no-color-moved-ws large change 0.38(0.33+0.05) 0.38(0.33+0.05) +0.0%
4002.2: diff --color-moved --no-color-moved-ws large change 0.86(0.82+0.04) 0.88(0.84+0.04) +2.3%
4002.3: diff --color-moved-ws=allow-indentation-change large change 0.97(0.94+0.03) 0.86(0.81+0.05) -11.3%
4002.4: log --no-color-moved --no-color-moved-ws 1.16(1.07+0.09) 1.16(1.06+0.09) +0.0%
4002.5: log --color-moved --no-color-moved-ws 1.32(1.26+0.06) 1.33(1.27+0.05) +0.8%
4002.6: log --color-moved-ws=allow-indentation-change 1.35(1.29+0.06) 1.33(1.24+0.08) -1.5%
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
moved_block_clear() was introduced in 74d156f4a1 ("diff
--color-moved-ws: fix double free crash", 2018-10-04) to free the
memory that was allocated when initializing a potential moved
block. However since 21536d077f ("diff --color-moved-ws: modify
allow-indentation-change", 2018-11-23) initializing a potential moved
block no longer allocates any memory. Up until the last commit we were
relying on moved_block_clear() to set the `match` pointer to NULL when
a block stopped matching, but since that commit we do not clear a
moved block that does not match so it does not make sense to clear
them elsewhere.
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Rather than setting `match` to NULL and then looping over the list of
potential matched blocks for a second time to remove blocks with no
matches just filter out the blocks with no matches as we go.
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
After the last two commits pmb_advance_or_null() and
pmb_advance_or_null_multi_match() differ only in the comparison they
perform. Lets simplify the code by combining them into a single
function.
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This change will allow us to easily combine pmb_advance_or_null() and
pmb_advance_or_null_multi_match() in the next commit. Calling
xdiff_compare_lines() directly rather than using a function pointer
from the hash map has little effect on the run time.
Test HEAD^ HEAD
-------------------------------------------------------------------------------------------------------------
4002.1: diff --no-color-moved --no-color-moved-ws large change 0.38(0.35+0.03) 0.38(0.32+0.06) +0.0%
4002.2: diff --color-moved --no-color-moved-ws large change 0.87(0.83+0.04) 0.87(0.80+0.06) +0.0%
4002.3: diff --color-moved-ws=allow-indentation-change large change 0.97(0.92+0.04) 0.97(0.93+0.04) +0.0%
4002.4: log --no-color-moved --no-color-moved-ws 1.17(1.06+0.10) 1.16(1.10+0.05) -0.9%
4002.5: log --color-moved --no-color-moved-ws 1.32(1.24+0.08) 1.31(1.22+0.09) -0.8%
4002.6: log --color-moved-ws=allow-indentation-change 1.36(1.25+0.10) 1.35(1.25+0.10) -0.7%
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If we already have a block of potentially moved lines then as we move
down the diff we need to check if the next line of each potentially
moved line matches the current line of the diff. The implementation of
--color-moved-ws=allow-indentation-change was needlessly performing
this check on all the lines in the diff that matched the current line
rather than just the current line. To exacerbate the problem finding
all the other lines in the diff that match the current line involves a
fuzzy lookup so we were wasting even more time performing a second
comparison to filter out the non-matching lines. Fixing this reduces
time to run
git diff --color-moved-ws=allow-indentation-change v2.28.0 v2.29.0
by 93% compared to master and simplifies the code.
Test HEAD^ HEAD
---------------------------------------------------------------------------------------------------------------
4002.1: diff --no-color-moved --no-color-moved-ws large change 0.38 (0.35+0.03) 0.38(0.35+0.03) +0.0%
4002.2: diff --color-moved --no-color-moved-ws large change 0.86 (0.80+0.06) 0.87(0.83+0.04) +1.2%
4002.3: diff --color-moved-ws=allow-indentation-change large change 19.01(18.93+0.06) 0.97(0.92+0.04) -94.9%
4002.4: log --no-color-moved --no-color-moved-ws 1.16 (1.06+0.09) 1.17(1.06+0.10) +0.9%
4002.5: log --color-moved --no-color-moved-ws 1.32 (1.25+0.07) 1.32(1.24+0.08) +0.0%
4002.6: log --color-moved-ws=allow-indentation-change 1.71 (1.64+0.06) 1.36(1.25+0.10) -20.5%
Test master HEAD
---------------------------------------------------------------------------------------------------------------
4002.1: diff --no-color-moved --no-color-moved-ws large change 0.38 (0.33+0.05) 0.38(0.35+0.03) +0.0%
4002.2: diff --color-moved --no-color-moved-ws large change 0.80 (0.75+0.04) 0.87(0.83+0.04) +8.7%
4002.3: diff --color-moved-ws=allow-indentation-change large change 14.20(14.15+0.05) 0.97(0.92+0.04) -93.2%
4002.4: log --no-color-moved --no-color-moved-ws 1.15 (1.05+0.09) 1.17(1.06+0.10) +1.7%
4002.5: log --color-moved --no-color-moved-ws 1.30 (1.19+0.11) 1.32(1.24+0.08) +1.5%
4002.6: log --color-moved-ws=allow-indentation-change 1.70 (1.63+0.06) 1.36(1.25+0.10) -20.0%
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Now that we reliably end a block when the sign changes we don't need
the whitespace delta calculation to rely on the sign.
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When marking moved lines it is possible for a block of potential
matched lines to extend past a change in sign when there is a sequence
of added lines whose text matches the text of a sequence of deleted
and added lines. Most of the time either `match` will be NULL or
`pmb_advance_or_null()` will fail when the loop encounters a change of
sign but there are corner cases where `match` is non-NULL and
`pmb_advance_or_null()` successfully advances the moved block despite
the change in sign.
One consequence of this is highlighting a short line as moved when it
should not be. For example
-moved line # Correctly highlighted as moved
+short line # Wrongly highlighted as moved
context
+moved line # Correctly highlighted as moved
+short line
context
-short line
The other consequence is coloring a moved addition following a moved
deletion in the wrong color. In the example below the first "+moved
line 3" should be highlighted as newMoved not newMovedAlternate.
-moved line 1 # Correctly highlighted as oldMoved
-moved line 2 # Correctly highlighted as oldMovedAlternate
+moved line 3 # Wrongly highlighted as newMovedAlternate
context # Everything else is highlighted correctly
+moved line 2
+moved line 3
context
+moved line 1
-moved line 3
These false matches are more likely when using --color-moved-ws with
the exception of --color-moved-ws=allow-indentation-change which ties
the sign of the current whitespace delta to the sign of the line to
avoid this problem. The fix is to check that the sign of the new line
being matched is the same as the sign of the line that started the
block of potential matches.
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
b0a2ba4776 ("diff --color-moved=zebra: be stricter with color
alternation", 2018-11-23) sought to avoid using the alternate colors
unless there are two adjacent moved blocks of the same
sign. Unfortunately it contains two bugs that prevented it from fixing
the problem properly. Firstly `last_symbol` is reset at the start of
each iteration of the loop losing the symbol of the last line and
secondly when deciding whether to use the alternate color it should be
checking if the current line is the same sign of the last line, not a
different sign. The combination of the two errors means that we still
use the alternate color when we should do but we also use it when we
shouldn't. This is most noticable when using
--color-moved-ws=allow-indentation-change with hunks like
-this line gets indented
+ this line gets indented
where the post image is colored with newMovedAlternate rather than
newMoved. While this does not matter much, the next commit will change
the coloring to be correct in this case, so lets fix the bug here to
make it clear why the output is changing and add a regression test.
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This code is quite heavily indented and having it in its own function
simplifies an upcoming change.
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If a block of potentially moved lines is not long enough then the
DIFF_SYMBOL_MOVED_LINE flag is cleared on the matching lines so they
are not marked as moved. To avoid problems when we start rewinding
after an unsuccessful match in a couple of commits time make sure all
the move related flags are cleared, not just DIFF_SYMBOL_MOVED_LINE.
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Change a pattern of hardcoding an "argv" array size, populating it and
assigning to the "argv" member of "struct child_process" to instead
use "strvec_push()" to add data to the "args" member.
As noted in the preceding commit this moves us further towards being
able to remove the "argv" member in a subsequent commit
These callers could have used strvec_pushl(), but moving to
strvec_push() makes the diff easier to read, and keeps the arguments
aligned as before.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In C it isn't required to specify that all members of a struct are
zero'd out to 0, NULL or '\0', just providing a "{ 0 }" will
accomplish that.
Let's also change code that provided N zero'd fields to just
provide one, and change e.g. "{ NULL }" to "{ 0 }" for
consistency. I.e. even if the first member is a pointer let's use "0"
instead of "NULL". The point of using "0" consistently is to pick one,
and to not have the reader wonder why we're not using the same pattern
everywhere.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The diff_populate_filespec() method is used to describe the diff after a
merge operation is complete. In order to avoid expanding a sparse index,
the reuse_worktree_file() needs to be adapted to ignore files that are
outside of the sparse-checkout cone. The file names and OIDs used for
this check come from the merged tree in the case of the ORT strategy,
not the index, hence the ability to look into these paths without having
already expanded the index.
The work done by reuse_worktree_file() is only an optimization, and
requires the file being on disk for it to be of any value. Thus, it is
safe to exit the method early if we do not expect the file on disk.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When I was fixing fuzzies as I updating po/id.po for 2.33.0 l10n round,
I noticed a triple-dash typo (--pickaxe-all) at diff.c, which according
to git-diff(1) manpage, the correct option name should be --pickaxe-all.
Fix the typo.
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Acked-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Documentation on "git diff -l<n>" and diff.renameLimit have been
updated, and the defaults for these limits have been raised.
* en/rename-limits-doc:
rename: bump limit defaults yet again
diffcore-rename: treat a rename_limit of 0 as unlimited
doc: clarify documentation for rename/copy limits
diff: correct warning message when renameLimit exceeded
These were last bumped in commit 92c57e5c1d (bump rename limit
defaults (again), 2011-02-19), and were bumped both because processors
had gotten faster, and because people were getting ugly merges that
caused problems and reporting it to the mailing list (suggesting that
folks were willing to spend more time waiting).
Since that time:
* Linus has continued recommending kernel folks to set
diff.renameLimit=0 (maps to 32767, currently)
* Folks with repositories with lots of renames were happy to set
merge.renameLimit above 32767, once the code supported that, to
get correct cherry-picks
* Processors have gotten faster
* It has been discovered that the timing methodology used last time
probably used too large example files.
The last point is probably worth explaining a bit more:
* The "average" file size used appears to have been average blob size
in the linux kernel history at the time (probably v2.6.25 or
something close to it).
* Since bigger files are modified more frequently, such a computation
weights towards larger files.
* Larger files may be more likely to be modified over time, but are
not more likely to be renamed -- the mean and median blob size
within a tree are a bit higher than the mean and median of blob
sizes in the history leading up to that version for the linux
kernel.
* The mean blob size in v2.6.25 was half the average blob size in
history leading to that point
* The median blob size in v2.6.25 was about 40% of the mean blob size
in v2.6.25.
* Since the mean blob size is more than double the median blob size,
any file as big as the mean will not be compared to any files of
median size or less (because they'd be more than 50% dissimilar).
* Since it is the number of files compared that provides the O(n^2)
behavior, median-sized files should matter more than mean-sized
ones.
The combined effect of the above is that the file size used in past
calculations was likely about 5x too large. Combine that with a CPU
performance improvement of ~30%, and we can increase the limits by
a factor of sqrt(5/(1-.3)) = 2.67, while keeping the original stated
time limits.
Keeping the same approximate time limit probably makes sense for
diff.renameLimit (there is no progress feedback in e.g. git log -p),
but the experience above suggests merge.renameLimit could be extended
significantly. In fact, it probably would make sense to have an
unlimited default setting for merge.renameLimit, but that would
likely need to be coupled with changes to how progress is displayed.
(See https://lore.kernel.org/git/YOx+Ok%2FEYvLqRMzJ@coredump.intra.peff.net/
for details in that area.) For now, let's just bump the approximate
time limit from 10s to 1m.
(Note: We do not want to use actual time limits, because getting results
that depend on how loaded your system is that day feels bad, and because
we don't discover that we won't get all the renames until after we've
put in a lot of work rather than just upfront telling the user there are
too many files involved.)
Using the original time limit of 2s for diff.renameLimit, and bumping
merge.renameLimit from 10s to 60s, I found the following timings using
the simple script at the end of this commit message (on an AWS c5.xlarge
which reports as "Intel(R) Xeon(R) Platinum 8124M CPU @ 3.00GHz"):
N Timing
1300 1.995s
7100 59.973s
So let's round down to nice even numbers and bump the limits from
400->1000, and from 1000->7000.
Here is the measure_rename_perf script (adapted from
https://lore.kernel.org/git/20080211113516.GB6344@coredump.intra.peff.net/
in particular to avoid triggering the linear handling from
basename-guided rename detection):
#!/bin/bash
n=$1; shift
rm -rf repo
mkdir repo && cd repo
git init -q -b main
mkdata() {
mkdir $1
for i in `seq 1 $2`; do
(sed "s/^/$i /" <../sample
echo tag: $1
) >$1/$i
done
}
mkdata initial $n
git add .
git commit -q -m initial
mkdata new $n
git add .
cd new
for i in *; do git mv $i $i.renamed; done
cd ..
git rm -q -rf initial
git commit -q -m new
time git diff-tree -M -l0 --summary HEAD^ HEAD
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The warning when quadratic rename detection was skipped referred to
"inexact rename detection". For years, the only linear portion of
rename detection was looking for exact renames, so "inexact rename
detection" was an accurate way to refer to the quadratic portion of
rename detection. However, that changed with commit bd24aa2f97
(diffcore-rename: guide inexact rename detection based on basenames,
2021-02-14). Let's instead use the term "exhaustive rename detection"
to refer to the quadratic portion.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Rewrite the backend for "diff -G/-S" to use pcre2 engine when
available.
* ab/pickaxe-pcre2: (22 commits)
xdiff-interface: replace discard_hunk_line() with a flag
xdiff users: use designated initializers for out_line
pickaxe -G: don't special-case create/delete
pickaxe -G: terminate early on matching lines
xdiff-interface: allow early return from xdiff_emit_line_fn
xdiff-interface: prepare for allowing early return
pickaxe -S: slightly optimize contains()
pickaxe: rename variables in has_changes() for brevity
pickaxe -S: support content with NULs under --pickaxe-regex
pickaxe: assert that we must have a needle under -G or -S
pickaxe: refactor function selection in diffcore-pickaxe()
perf: add performance test for pickaxe
pickaxe/style: consolidate declarations and assignments
diff.h: move pickaxe fields together again
pickaxe: die when --find-object and --pickaxe-all are combined
pickaxe: die when -G and --pickaxe-regex are combined
pickaxe tests: add missing test for --no-pickaxe-regex being an error
pickaxe tests: test for -G, -S and --find-object incompatibility
pickaxe tests: add test for "log -S" not being a regex
pickaxe tests: add test for diffgrep_consume() internals
...
The word-diff mode has been taught to work better with a word
regexp that can match an empty string.
* pw/word-diff-zero-width-matches:
word diff: handle zero length matches
Remove the dummy discard_hunk_line() function added in
3b40a090fd (diff: avoid generating unused hunk header lines,
2018-11-02) in favor of having a new XDL_EMIT_NO_HUNK_HDR flag, for
use along with the two existing and similar XDL_EMIT_* flags.
Unlike the recently amended xdiff_emit_line_fn interface which'll be
called in a loop in xdl_emit_diff(), the hunk header is only emitted
once.
It makes more sense to pass this as a flag than provide a dummy
callback because that function may be able to skip doing certain work
if it knows the caller is doing nothing with the hunk header.
It would be possible to do so in the case of -U0 now, but the benefit
of doing so is so small that I haven't bothered. But this leaves the
door open to that, and more importantly makes the API use more
intuitive.
The reason we're putting a flag in the gap between 1<<0 and 1<<2 is
that the old 1<<1 flag was removed in 907681e940 (xdiff: drop
XDL_EMIT_COMMON, 2016-02-23) without re-ordering the remaining flags.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Change the function prototype of xdiff_emit_line_fn to return an "int"
instead of "void". Change all of those functions to "return 0",
nothing checks those return values yet, and no behavior is being
changed.
In subsequent commits the interface will be changed to allow early
return via this new return value.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Neither the --pickaxe-all documentation nor --find-object's has ever
suggested that you can combine the two. See f506b8e8b5 (git log/diff:
add -G<regexp> that greps in the patch text, 2010-08-23) and
15af58c1ad (diffcore: add a pickaxe option to find a specific blob,
2018-01-04).
But we've silently tolerated it, which makes the logic in
diffcore_pickaxe() harder to reason about. Let's assert that we won't
have the two combined.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When the -G and --pickaxe-regex options are combined we simply ignore
the --pickaxe-regex option. Let's die instead as suggested by our
documentation, since -G is always a regex.
When --pickaxe-regex was added in d01d8c6782 (Support for pickaxe
matching regular expressions, 2006-03-29) only the -S option
existed. Then when -G was added in f506b8e8b5 (git log/diff: add
-G<regexp> that greps in the patch text, 2010-08-23) neither the
documentation for --pickaxe-regex was updated accordingly, nor was
something like this assertion added.
Since 5bc3f0b567 (diffcore-pickaxe doc: document -S and -G properly,
2013-05-31) we've claimed that --pickaxe-regex should only be used
with -S, but have silently tolerated combining it with -G, let's die
instead.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If find_word_boundaries() encounters a zero length match (which can be
caused by matching a newline or using '*' instead of '+' in the regex)
we stop splitting the input into words which generates an inaccurate
diff. To fix this increment the start point when there is a zero
length match and try a new match. This is safe as posix regular
expressions always return the longest available match so a zero length
match means there are no longer matches available from the current
position.
Commit bf82940dbf (color-words: enable REG_NEWLINE to help user,
2009-01-17) prevented matching newlines in negated character classes
but it is still possible for the user to have an explicit newline
match in the regex which could cause a zero length match.
One could argue that having explicit newline matches or using '*'
rather than '+' are user errors but it seems to be better to work
round them than produce inaccurate diffs.
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Up until recently, object IDs did not have an algorithm member, only a
hash. Consequently, it was possible to share one null (all-zeros)
object ID among all hash algorithms. Now that we're going to be
handling objects from multiple hash algorithms, it's important to make
sure that all object IDs have a correct algorithm field.
Introduce a per-algorithm null OID, and add it to struct hash_algo.
Introduce a wrapper function as well, and use it everywhere we used to
use the null_oid constant.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we're hashing a value which is going to be an object ID, we want to
zero-pad that value if necessary. To do so, use the final_oid_fn
instead of the final_fn anytime we're going to create an object ID to
ensure we perform this operation.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add and apply a semantic patch for converting code that open-codes
CALLOC_ARRAY to use it instead. It shortens the code and infers the
element size automatically.
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git {diff,log} --{skip,rotate}-to=<path>" allows the user to
discard diff output for early paths or move them to the end of the
output.
* jc/diffcore-rotate:
diff: --{rotate,skip}-to=<path>
In the implementation of "git difftool", there is a case where the
user wants to start viewing the diffs at a specific path and
continue on to the rest, optionally wrapping around to the
beginning. Since it is somewhat cumbersome to implement such a
feature as a post-processing step of "git diff" output, let's
support it internally with two new options.
- "git diff --rotate-to=C", when the resulting patch would show
paths A B C D E without the option, would "rotate" the paths to
shows patch to C D E A B instead. It is an error when there is
no patch for C is shown.
- "git diff --skip-to=C" would instead "skip" the paths before C,
and shows patch to C D E. Again, it is an error when there is no
patch for C is shown.
- "git log [-p]" also accepts these two options, but it is not an
error if there is no change to the specified path. Instead, the
set of output paths are rotated or skipped to the specified path
or the first path that sorts after the specified path.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Fix a memory leak in 296d4a94e7 (diff: add -I<regex> that ignores
matching changes, 2020-10-20) by freeing the memory it allocates in
the newly introduced diff_free(). See the previous commit for details
on that.
This memory leak was intentionally introduced in 296d4a94e7, see the
discussion on a previous iteration of it in
https://lore.kernel.org/git/xmqqeelycajx.fsf@gitster.c.googlers.com/
At that time freeing the memory was somewhat tedious, but since it
isn't anymore with the newly introduced diff_free() let's use it.
Let's retain the pattern for diff_free_file() and add a
diff_free_ignore_regex(), even though (unlike "diff_free_file") we
don't need to call it elsewhere. I think this'll make for more
readable code than gradually accumulating a giant diff_free()
function, sharing "int i" across unrelated code etc.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a diff_free() function to free anything we may have allocated in
the "diff_options" struct, and the ability to make calling it a noop
by setting "no_free" in "diff_options".
This is required because when e.g. "git diff" is run we'll allocate
things in that struct, use the diff machinery once, and then exit.
But if we run e.g. "git log -p" we're going to re-use what we
allocated across multiple diff_flush() calls, and only want to free
things at the end.
We've thus ended up with features like the recently added "diff -I"[1]
where we'll leak memory. As it turns out it could have simply used the
pattern established in 6ea57703f6 (log: prepare log/log-tree to reuse
the diffopt.close_file attribute, 2016-06-22).
Manually adding more such flags to things log_tree_commit() every time
we need to allocate something would be tedious. Let's instead move
that fclose() code it to a new diff_free(), in anticipation of freeing
more things in that function in follow-up commits.
Some functions such as log_tree_commit() need an idiom of optionally
retaining a previous "no_free", as they may either free the memory
themselves, or their caller may do so. I'm keeping that idiom in
log_show_early() for good measure, even though I don't think it's
currently called in this manner. It also gets passed an existing
"struct rev_info", so future callers may want to set the "no_free"
flag.
This change is a bit hard to read because while the freeing pattern
we're introducing isn't unusual, the "file" member is a special
snowflake. We usually don't want to fclose() it. This is because
"file" is usually stdout, in which case we don't want to fclose()
it. We only want to opt-in to closing it when we e.g. open a file on
the filesystem. Thus the opt-in "close_file" flag.
So the API in general just needs a "no_free" flag to defer freeing,
but the "file" member still needs its "close_file" flag. This is made
more confusing because while refactoring this code we could replace
some "close_file=0" with "no_free=1", whereas others need to set both
flags.
This is because there were some cases where an existing "close_file=0"
meant "let's defer deallocation", and others where it meant "we don't
want to close this file handle at all".
1. 296d4a94e7 (diff: add -I<regex> that ignores matching changes,
2020-10-20)
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git diff" showed a submodule working tree with untracked cruft as
"Submodule commit <objectname>-dirty", but a natural expectation is
that the "-dirty" indicator would align with "git describe --dirty",
which does not consider having untracked files in the working tree
as source of dirtiness. The inconsistency has been fixed.
* sj/untracked-files-in-submodule-directory-is-not-dirty:
diff: do not show submodule with untracked files as "-dirty"
"git diff -I<pattern> -exit-code" should exit with 0 status when
all the changes match the ignored pattern, but it didn't.
* jc/diff-I-status-fix:
diff: correct interaction between --exit-code and -I<pattern>
