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>
Add some tests so we can monitor changes to the performance of the
move detection code. The tests record the performance --color-moved
and --color-moved-ws=allow-indentation-change for a large diff and a
sequence of smaller diffs. The range of commits used for the large
diff can be customized by exporting TEST_REV_A and TEST_REV_B when
running the test.
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We use "type array[];" syntax for the flex-array member at the end
of a struct under C99 or later, except when we are building with
older SUNPRO_C compilers. As we find more vendor compilers that
claim to grok C99 but not understand the flex-array syntax, the
existing "If we are using C99, but not with these compilers..."
conditional will keep growing.
Make it more manageable by listing vendor-specific exceptions
earlier, with the expectation that new exceptions will not be
combined into existing ones to make the condition longer, and
instead will be implemented as a new "#elif" in the cascade of
similar to old SUNPRO_C, we can just add a single line
#elif defined(_MSC_VER)
immediately before "#elif defined(__GNUC__)" to cause us to fallback
to the safer but a bit wasteful version.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When creating a subprocess with a temporary ODB, we set the
GIT_QUARANTINE_ENVIRONMENT env var to tell child Git processes not
to update refs, since the tmp-objdir may go away.
Introduce a similar mechanism for in-process temporary ODBs when
we call tmp_objdir_replace_primary_odb. Now both mechanisms set
the disable_ref_updates flag on the odb, which is queried by
the ref_transaction_prepare function.
Peff's test case [1] was invoking ref updates via the cachetextconv
setting. That particular code silently does nothing when a ref
update is forbidden. See the call to notes_cache_put in
fill_textconv where errors are ignored.
[1] https://lore.kernel.org/git/YVOn3hDsb5pnxR53@coredump.intra.peff.net/
Reported-by: Jeff King <peff@peff.net>
Signed-off-by: Neeraj Singh <neerajsi@microsoft.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The tmp_objdir API provides the ability to create temporary object
directories, but was designed with the goal of having subprocesses
access these object stores, followed by the main process migrating
objects from it to the main object store or just deleting it. The
subprocesses would view it as their primary datastore and write to it.
Here we add the tmp_objdir_replace_primary_odb function that replaces
the current process's writable "main" object directory with the
specified one. The previous main object directory is restored in either
tmp_objdir_migrate or tmp_objdir_destroy.
For the --remerge-diff usecase, add a new `will_destroy` flag in `struct
object_database` to mark ephemeral object databases that do not require
fsync durability.
Add 'git prune' support for removing temporary object databases, and
make sure that they have a name starting with tmp_ and containing an
operation-specific name.
Based-on-patch-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Neeraj Singh <neerajsi@microsoft.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The point of DEVELOPER=1 is to turn up the warnings so we can catch
portability or correctness mistakes at the compiler level. But since
modern compilers tend to default to modern standards like gnu17, we
might miss warnings about older standards, even though we expect Git to
build with compilers that use them.
So it's helpful for developer builds to set the -std argument to our
lowest-common denominator. Traditionally this was c89, but since we're
moving to assuming c99 in 7bc341e21b (git-compat-util: add a test
balloon for C99 support, 2021-12-01) that seems like a good spot to
land. And as explained in that commit, we want "gnu99" because we still
want to take advantage of some extensions when they're available.
The new argument kicks in only for clang and gcc (which we know to
support "-std=" and "gnu" standards). And only for compiler versions
which default to a newer standard. That will avoid accidentally
silencing any build problems that non-developers would run into on older
compilers that default to c89.
My digging found that the default switched to gnu11 in gcc 5.1.0.
Clang's documentation is less clear, but has done so since at least
clang-7. So that's what I put in the conditional here. It's OK to err on
the side of not-enabling this for older compilers. Most developers (as
well as CI) are using much more recent versions, so any warnings will
eventually surface.
A concrete example is anonymous unions, which became legal in c11.
Without this patch, "gcc -pedantic" will not complain about them, but
will if we add in "-std=gnu99".
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Fix a segfault in the --set-upstream option added in
24bc1a1292 (pull, fetch: add --set-upstream option, 2019-08-19) added
in v2.24.0.
The code added there did not do the same checking we do for "git
branch" itself since 8efb8899cf (branch: segfault fixes and
validation, 2013-02-23), which in turn fixed the same sort of segfault
I'm fixing now in "git branch --set-upstream-to", see
6183d826ba (branch: introduce --set-upstream-to, 2012-08-20).
The warning message I'm adding here is an amalgamation of the error
added for "git branch" in 8efb8899cf, and the error output
install_branch_config() itself emits, i.e. it trims "refs/heads/" from
the name and says "branch X on remote", not "branch refs/heads/X on
remote".
I think it would make more sense to simply die() here, but in the
other checks for --set-upstream added in 24bc1a1292 we issue a
warning() instead. Let's do the same here for consistency for now.
There was an earlier submitted alternate way of fixing this in [1],
due to that patch breaking threading with the original report at [2] I
didn't notice it before authoring this version. I think the more
detailed warning message here is better, and we should also have tests
for this behavior.
The --no-rebase option to "git pull" is needed as of the recently
merged 7d0daf3f12 (Merge branch 'en/pull-conflicting-options',
2021-08-30).
1. https://lore.kernel.org/git/20210706162238.575988-1-clemens@endorphin.org/
2. https://lore.kernel.org/git/CAG6gW_uHhfNiHGQDgGmb1byMqBA7xa8kuH1mP-wAPEe5Tmi2Ew@mail.gmail.com/
Reported-by: Clemens Fruhwirth <clemens@endorphin.org>
Reported-by: Jan Pokorný <poki@fnusa.cz>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
cb_unlink is broken once a node is no longer self-referential
due to subsequent insertions. This is a consequence of an
intrusive implementation and I'm not sure if it's easily fixable
while retaining our cache-friendly intrusive property (I've
tried for several hours in another project).
In any case, we're not using cb_unlink anywhere in our codebase,
just get rid of it to avoid misleading future readers.
Signed-off-by: Eric Wong <e@80x24.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This still leaves some other direct filesystem access. Currently, the files
backend does not allow invalidly named symrefs. Fixes for this are currently in
the 'seen' branch
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use this flag with the test-helper in t1430, to avoid direct writes to the ref
database.
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This lets the ref-store test helper write non-existent or unparsable objects
into the ref storage.
Use this to make t1006 and t3800 independent of the files storage backend.
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
REF_IS_PRUNING is right below this comment, so it clearly does not belong in
this comment. This was apparently introduced in commit 5ac95fee (Nov 5, 2017
"refs: tidy up and adjust visibility of the `ref_update` flags").
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This lets tests use REF_XXXX constants instead of hardcoded integers. The flag
names should be separated by a ','.
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Nobody uses force_create=0, so this flag is unnecessary.
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Adjust code added in 7463064b28 (object.h: add
lookup_object_by_type() function, 2021-06-22) to use the BUG()
function.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Change code that was added in 8f4f8f4579 (guard against new pathspec
magic in pathspec matching code, 2013-07-14) to use the BUG() macro
instead of emitting a "fatal" message with the "__FILE__"-name and
"__LINE__"-numbers.
The original code predated the existence of the BUG() function, which
was added in d8193743e0 (usage.c: add BUG() function, 2017-05-12).
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In 7141efab24 (strbuf: clarify assertion in strbuf_setlen(),
2011-04-27) this 'die("BUG: "' invocation was added with the rationale
that strbuf.c had existing users doing the same, but those users were
later changed to use BUG() in 033abf97fc (Replace all die("BUG: ...")
calls by BUG() ones, 2018-05-02). Let's do the same here.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Change this code added in da93d12b00 (pack-objects: be incredibly
anal about stdio semantics, 2006-04-02) to use BUG() instead.
See 1a07e59c3e (Update messages in preparation for i18n, 2018-07-21)
for when the "BUG: " prefix was added, and [1] for background on the
Solaris behavior that prompted the exhaustive error checking in this
fgets() loop.
1. https://lore.kernel.org/git/824.1144007555@lotus.CS.Berkeley.EDU/
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Change the main() function to call "exit()" instead of ending with a
"return" statement. The "exit()" function is our own wrapper that
calls trace2_cmd_exit_fl() for us, from git-compat-util.h:
#define exit(code) exit(trace2_cmd_exit_fl(__FILE__, __LINE__, (code)))
That "exit()" wrapper has been in use ever since ee4512ed48 (trace2:
create new combined trace facility, 2019-02-22).
This changes nothing about how we "exit()", as we'd invoke
"trace2_cmd_exit_fl()" in both cases due to the wrapper, this change
makes it easier to reason about this code, as we're now always
obviously relying on our "exit()" wrapper.
There is already code immediately downstream of our "main()" which has
a hard reliance on that, e.g. the various "exit()" calls downstream of
"cmd_main()" in "git.c".
We even had a comment in "t/helper/test-trace2.c" that seemed to be
confused about how the "exit()" wrapper interacted with uses of
"return", even though it was introduced in the same trace2 series in
a15860dca3 (trace2: t/helper/test-trace2, t0210.sh, t0211.sh,
t0212.sh, 2019-02-22), after the aforementioned ee4512ed48. Perhaps
it pre-dated the "exit()" wrapper?
This change makes the "trace2_cmd_exit()" macro orphaned, we now
always use "trace2_cmd_exit_fl()" directly, but let's keep that
simpler example in place. Even if we're unlikely to get another
"main()" other than the one in our "common-main.c", there's some value
in having the API documentation and example discuss a simpler version
that doesn't require an "exit()" wrapper macro.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Enable the sparse index for the 'git blame' command. The index was already
not expanded with this command, so the most interesting thing to do is to
add tests that verify that 'git blame' behaves correctly when the sparse
index is enabled and that its performance improves. More specifically, these
cases are:
1. The index is not expanded for 'blame' when given paths in the sparse
checkout cone at multiple levels.
2. Performance measurably improves for 'blame' with sparse index when given
paths in the sparse checkout cone at multiple levels.
The `p2000` tests demonstrate a ~60% execution time reduction when running
'blame' for a file two levels deep and and a ~30% execution time reduction
for a file three levels deep.
Test before after
----------------------------------------------------------------
2000.62: git blame f2/f4/a (full-v3) 0.31 0.32 +3.2%
2000.63: git blame f2/f4/a (full-v4) 0.29 0.31 +6.9%
2000.64: git blame f2/f4/a (sparse-v3) 0.55 0.23 -58.2%
2000.65: git blame f2/f4/a (sparse-v4) 0.57 0.23 -59.6%
2000.66: git blame f2/f4/f3/a (full-v3) 0.77 0.85 +10.4%
2000.67: git blame f2/f4/f3/a (full-v4) 0.78 0.81 +3.8%
2000.68: git blame f2/f4/f3/a (sparse-v3) 1.07 0.72 -32.7%
2000.99: git blame f2/f4/f3/a (sparse-v4) 1.05 0.73 -30.5%
We do not include paths outside the sparse checkout cone because blame
does not support blaming files that are not present in the working
directory. This is true in both sparse and full checkouts.
Signed-off-by: Lessley Dennington <lessleydennington@gmail.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Enable the sparse index within the 'git diff' command. Its implementation
already safely integrates with the sparse index because it shares code
with the 'git status' and 'git checkout' commands that were already
integrated. For more details see:
d76723ee53 (status: use sparse-index throughout, 2021-07-14)
1ba5f45132 (checkout: stop expanding sparse indexes, 2021-06-29)
The most interesting thing to do is to add tests that verify that 'git
diff' behaves correctly when the sparse index is enabled. These cases are:
1. The index is not expanded for 'diff' and 'diff --staged'
2. 'diff' and 'diff --staged' behave the same in full checkout, sparse
checkout, and sparse index repositories in the following partially-staged
scenarios (i.e. the index, HEAD, and working directory differ at a given
path):
1. Path is within sparse-checkout cone
2. Path is outside sparse-checkout cone
3. A merge conflict exists for paths outside sparse-checkout cone
The `p2000` tests demonstrate a ~44% execution time reduction for 'git
diff' and a ~86% execution time reduction for 'git diff --staged' using a
sparse index:
Test before after
-------------------------------------------------------------
2000.30: git diff (full-v3) 0.33 0.34 +3.0%
2000.31: git diff (full-v4) 0.33 0.35 +6.1%
2000.32: git diff (sparse-v3) 0.53 0.31 -41.5%
2000.33: git diff (sparse-v4) 0.54 0.29 -46.3%
2000.34: git diff --cached (full-v3) 0.07 0.07 +0.0%
2000.35: git diff --cached (full-v4) 0.07 0.08 +14.3%
2000.36: git diff --cached (sparse-v3) 0.28 0.04 -85.7%
2000.37: git diff --cached (sparse-v4) 0.23 0.03 -87.0%
Co-authored-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Lessley Dennington <lessleydennington@gmail.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Replace uses of the synonym --staged in t1092 tests with --cached (which
is the real and preferred option). This will allow consistency in the new
tests to be added with the upcoming change to enable the sparse index for
diff.
Signed-off-by: Lessley Dennington <lessleydennington@gmail.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Check whether git directory exists before adding any repo settings. If it
does not exist, BUG with the message that one cannot add settings for an
uninitialized repository. If it does exist, proceed with adding repo
settings.
Signed-off-by: Lessley Dennington <lessleydennington@gmail.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Move repo setup to occur after git directory is set up. This will protect
against test failures in the upcoming change to BUG in
prepare_repo_settings if no git directory exists.
Signed-off-by: Lessley Dennington <lessleydennington@gmail.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Return early if git directory does not exist. This will protect against
test failures in the upcoming change to BUG in prepare_repo_settings if no
git directory exists.
Signed-off-by: Lessley Dennington <lessleydennington@gmail.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Ensure correct git directory setup when -h is passed with commands. This
specifically applies to repos with special help text configuration
variables and to commands run with -h outside a repository. This
will also protect against test failures in the upcoming change to BUG in
prepare_repo_settings if no git directory exists.
Note: this diff is better seen when ignoring whitespace changes.
Co-authored-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Lessley Dennington <lessleydennington@gmail.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The sparse_dir_matches_path() method compares a cache entry that is a
sparse directory entry against a 'struct traverse_info *info' and a
'struct name_entry *p' to see if the cache entry has exactly the right
name for those other inputs.
This method was introduced in 523506d (unpack-trees: unpack sparse
directory entries, 2021-07-14), but included a significant mistake. The
path comparisons used 'info->name' instead of 'info->traverse_path'.
Since 'info->name' only stores a single tree entry name while
'info->traverse_path' stores the full path from root, this method does
not work when 'info' is in a subdirectory of a directory. Replacing the
right strings and their corresponding lengths make the method work
properly.
The previous change included a failing test that exposes this issue.
That test now passes. The critical detail is that as we go deep into
unpack_trees(), the logic for merging a sparse directory entry with a
tree entry during 'git checkout' relies on this
sparse_dir_matches_path() in order to avoid calling
traverse_trees_recursive() during unpack_callback() in this hunk:
if (!is_sparse_directory_entry(src[0], names, info) &&
traverse_trees_recursive(n, dirmask, mask & ~dirmask,
names, info) < 0) {
return -1;
}
For deep paths, the short-circuit never occurred and
traverse_trees_recursive() was being called incorrectly and that was
causing other strange issues. Specifically, the error message from the
now-passing test previously included this:
error: Your local changes to the following files would be overwritten by checkout:
deep/deeper1/deepest2/a
deep/deeper1/deepest3/a
Please commit your changes or stash them before you switch branches.
Aborting
These messages occurred because the 'current' cache entry in
twoway_merge() was showing as NULL because the index did not contain
entries for the paths contained within the sparse directory entries. We
instead had 'oldtree' given as the entry at HEAD and 'newtree' as the
entry in the target tree. This led to reject_merge() listing these
paths.
Now that sparse_dir_matches_path() works the same for deep paths as it
does for shallow depths, the rest of the logic kicks in to properly
handle modifying the sparse directory entries as designed.
Reported-by: Gustave Granroth <gus.gran@gmail.com>
Reported-by: Mike Marcelais <michmarc@exchange.microsoft.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Extend the repository data in the setup of t1092 to include more
directories within two parent directories. This reproduces a bug found
by users of the sparse index feature with suitably-complicated
sparse-checkout definitions.
Add a failing test that fails in its first 'git checkout deepest' run in
the sparse index case with this error:
error: Your local changes to the following files would be overwritten by checkout:
deep/deeper1/deepest2/a
deep/deeper1/deepest3/a
Please commit your changes or stash them before you switch branches.
Aborting
The next change will fix this error, and that fix will make it clear why
the extra depth is necessary for revealing this bug. The assignment of
the sparse-checkout definition to include deep/deeper1/deepest as a
sibling directory is important to ensure that deep/deeper1 is not a
sparse directory entry, but deep/deeper1/deepest2 is.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We documented that with grep.patternType set to default, the "git
grep" command returns to "the default matching behavior" in 84befcd0
(grep: add a grep.patternType configuration setting, 2012-08-03).
The grep.extendedRegexp configuration variable was the only way to
configure the behavior before that, after b22520a3 (grep: allow -E
and -n to be turned on by default via configuration, 2011-03-30)
introduced it.
It is understandable that we referred to the behavior that honors
the older configuration variable as "the default matching"
behavior. It is fairly clear in its log message:
When grep.patternType is set to a value other than "default", the
grep.extendedRegexp setting is ignored. The value of "default" restores
the current default behavior, including the grep.extendedRegexp
behavior.
But when the paragraph is read in isolation by a new person who is
not aware of that backstory (which is the synonym for "most users"),
the "default matching behavior" can be read as "how 'git grep'
behaves without any configuration variables or options", which is
"match the pattern as BRE".
Clarify what the passage means by elaborating what the phrase
"default matching behavior" wanted to mean.
Helped-by: Johannes Altmanninger <aclopte@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A couple of test scripts have actually been adapted to accommodate for a
configurable default branch name, but they still overrode it via the
`GIT_TEST_*` variable. Let's drop that override where possible.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commands executed from `git rebase --exec` can give different behavior
from within that environment than they would outside of it, due to the
fact that sequencer.c exports both GIT_DIR and GIT_WORK_TREE. For
example, if the relevant script calls something like
git -C ../otherdir log --format=%H --no-walk
the user may be surprised to find that the command above does not show a
commit hash from ../otherdir, because $GIT_DIR prevents automatic gitdir
detection and makes the -C option useless.
This is a regression in behavior from the original legacy
implemented-in-shell rebase. It is perhaps rare for it to cause
problems in practice, especially since most small problems that were
caused by this area of bugs has been fixed-up in the past in a way that
masked the particular bug observed without fixing the real underlying
problem.
An explanation of how we arrived at the current situation is perhaps
merited. The setting of GIT_DIR and GIT_WORK_TREE done by sequencer.c
arose from a sequence of historical accidents:
* When rebase was implemented as a shell command, it would call
git-sh-setup, which among other things would set GIT_DIR -- but not
export it. This meant that when rebase --exec commands were run via
/bin/sh -c "$COMMAND"
they would not inherit the GIT_DIR setting. The fact that GIT_DIR
was not set in the run $COMMAND is the behavior we'd like to restore.
* When the rebase--helper builtin was introduced to allow incrementally
replacing shell with C code, we had an implementation that was half
shell, half C. In particular, commit 18633e1a22 ("rebase -i: use the
rebase--helper builtin", 2017-02-09) added calls to
exec git rebase--helper ...
which caused rebase--helper to inherit the GIT_DIR environment
variable from the shell. git's setup would change the environment
variable from an absolute path to a relative one (".git"), but would
leave it set. This meant that when rebase --exec commands were run
via
run_command_v_opt(...)
they would inherit the GIT_DIR setting.
* In commit 09d7b6c6fa ("sequencer: pass absolute GIT_DIR to exec
commands", 2017-10-31), it was noted that the GIT_DIR caused problems
with some commands; e.g.
git rebase --exec 'cd subdir && git describe' ...
would have GIT_DIR=.git which was invalid due to the change to the
subdirectory. Instead of questioning why GIT_DIR was set, that commit
instead made sequencer change GIT_DIR to be an absolute path and
explicitly export it via
argv_array_pushf(&child_env, "GIT_DIR=%s", absolute_path(get_git_dir()));
run_command_v_opt_cd_env(..., child_env.argv)
* In commit ab5e67d751 ("sequencer: pass absolute GIT_WORK_TREE to exec
commands", 2018-07-14), it was noted that when GIT_DIR is set but
GIT_WORK_TREE is not, that we do not discover GIT_WORK_TREE but just
assume it is '.'. That is incorrect if trying to run commands from a
subdirectory. However, rather than question why GIT_DIR was set, that
commit instead also added GIT_WORK_TREE to the list of things to
export.
Each of the above problems would have been fixed automatically when
git-rebase became a full builtin, had it not been for the fact that
sequencer.c started exporting GIT_DIR and GIT_WORK_TREE in the interim.
Stop exporting them now.
Signed-off-by: Elijah Newren <newren@gmail.com>
Acked-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Acked-by: Johannes Altmanninger <aclopte@gmail.com>
Acked-by: Phillip Wood <phillip.wood123@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
name-rev has a MERGE_TRAVERSAL_WEIGHT to say that traversing a second or
later parent of a merge should be 65535 times more expensive than a
first-parent traversal, as per ac076c29ae (name-rev: Fix non-shortest
description, 2007-08-27). The point of this weight is to prefer names
like
v2.32.0~1471^2
over names like
v2.32.0~43^2~15^2~11^2~20^2~31^2
which are two equally valid names in git.git for the same commit. Note
that the first follows 1472 parent traversals compared to a mere 125 for
the second. Weighting all traversals equally would clearly prefer the
second name since it has fewer parent traversals, but humans aren't
going to be traversing commits and they tend to have an easier time
digesting names with fewer segments. The fact that the former only has
two segments (~1471, ^2) makes it much simpler than the latter which has
six segments (~43, ^2, ~15, etc.). Since name-rev is meant to "find
symbolic names suitable for human digestion", we prefer fewer segments.
However, the particular rule implemented in name-rev would actually
prefer
v2.33.0-rc0~11^2~1
over
v2.33.0-rc0~20^2
because both have precisely one second parent traversal, and it gives
the tie breaker to shortest number of total parent traversals. Fewer
segments is more important for human consumption than number of hops, so
we'd rather see the latter which has one fewer segment.
Include the generation in is_better_name() and use a new
effective_distance() calculation so that we prefer fewer segments in
the printed name over fewer total parent traversals performed to get the
answer.
== Side-note on tie-breakers ==
When there are the same number of segments for two different names, we
actually use the name of an ancestor commit as a tie-breaker as well.
For example, for the commit cbdca289fb in the git.git repository, we
prefer the name v2.33.0-rc0~112^2~1 over v2.33.0-rc0~57^2~5. This is
because:
* cbdca289fb is the parent of 25e65b6dd5, which implies the name for
cbdca289fb should be the first parent of the preferred name for
25e65b6dd5
* 25e65b6dd5 could be named either v2.33.0-rc0~112^2 or
v2.33.0-rc0~57^2~4, but the former is preferred over the latter due
to fewer segments
* combine the two previous facts, and the name we get for cbdca289fb
is "v2.33.0-rc0~112^2~1" rather than "v2.33.0-rc0~57^2~5".
Technically, we get this for free out of the implementation since we
only keep track of one name for each commit as we walk history (and
re-add parents to the queue if we find a better name for those parents),
but the first bullet point above ensures users get results that feel
more consistent.
== Alternative Ideas and Meanings Discussed ==
One suggestion that came up during review was that shortest
string-length might be easiest for users to consume. However, such a
scheme would be rather computationally expensive (we'd have to track all
names for each commit as we traversed the graph) and would additionally
come with the possibly perplexing result that on a linear segment of
history we could rapidly swap back and forth on names:
MYTAG~3^2 would be preferred over MYTAG~9998
MYTAG~3^2~1 would NOT be preferred over MYTAG~9999
MYTAG~3^2~2 might be preferred over MYTAG~10000
Another item that came up was possible auxiliary semantic meanings for
name-rev results either before or after this patch. The basic answer
was that the previous implementation had no known useful auxiliary
semantics, but that for many repositories (most in my experience), the
new scheme does. In particular, the new name-rev output can often be
used to answer the question, "How or when did this commit get merged?"
Since that usefulness depends on how merges happen within the repository
and thus isn't universally applicable, details are omitted here but you
can see them at [1].
[1] https://lore.kernel.org/git/CABPp-BEeUM+3NLKDVdak90_UUeNghYCx=Dgir6=8ixvYmvyq3Q@mail.gmail.com/
Finally, it was noted that the algorithm could be improved by just
explicitly tracking the number of segments and using both it and
distance in the comparison, instead of giving a magic number that tries
to blend the two (and which therefore might give suboptimal results in
repositories with really huge numbers of commits that periodically merge
older code). However, "[this patch] seems to give us a much better
results than the current code, so let's take it and leave further
futzing outside the scope."
Signed-off-by: Elijah Newren <newren@gmail.com>
Acked-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Acked-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since 6b13bc3232 (xdiff: simplify comparison, 2021-11-17), we do not
call xdl_recmatch() from xdiffi.c's recs_match(), so we no longer need
the "flags" parameter. That in turn lets us drop the flags parameters
from the group-slide functions which call it.
There's no functional change here; it's just making these functions a
little simpler.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since 663c5ad035 (diff histogram: intern strings, 2021-11-17), our
cmp_recs() does not call xdl_recmatch(), and thus no longer needs an
xpparam_t struct from which to get the flags. We can drop the unused
parameter from the function, as well as the macro which wraps it.
There's no functional change here; it's just simplifying things (and
making -Wunused-parameter happier).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This macro has been unused since 43ca7530df (xdiff/xhistogram: rely on
xdl_trim_ends(), 2011-08-01). The function that called it went away
there, and its use in the CMP() macro was inlined. It probably should
have been deleted then, but nobody noticed.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
