Commit Graph

186 Commits

Author SHA1 Message Date
Junio C Hamano
2557c1183a Merge branch 'sg/bisect-approximately-halfway'
"git bisect start/next" in a large span of history spends a lot of
time trying to come up with exactly the half-way point; this can be
optimized by stopping when we see a commit that is close enough to
the half-way point.

* sg/bisect-approximately-halfway:
  bisect: loosen halfway() check for a large number of commits
2020-11-25 15:24:52 -08:00
SZEDER Gábor
0afcea70b1 bisect: loosen halfway() check for a large number of commits
'git bisect start ...' and subsequent 'git bisect (good|bad)' commands
can take quite a while when the given/remaining revision range between
good and bad commits is big and contains a lot of merge commits, e.g.
in git.git:

  $ git rev-list --count v1.6.0..v2.28.0
  44284
  $ time git bisect start v2.28.0 v1.6.0
  Bisecting: 22141 revisions left to test after this (roughly 15 steps)
  [e197c21807] unable_to_lock_die(): rename function from unable_to_lock_index_die()

  real    0m15.472s
  user    0m15.220s
  sys     0m0.255s

The majority of the runtime is spent in do_find_bisection(), where we
try to find a commit as close as possible to the halfway point between
the bad and good revisions, i.e. a commit from which the number of
reachable commits that are in the good-bad range is half the total
number of commits in that range.  So we count how many commits are
reachable in the good-bad range for each commit in that range, which
is quick and easy for a linear history, even over 300k commits in a
linear range are handled in ~0.3s on my machine.  Alas, handling merge
commits is non-trivial and quite expensive as the algorithm used seems
to be quadratic, causing the long runtime shown above.

Interestingly, look at what a big difference one additional commit
can make:

  $ git rev-list --count v1.6.0^..v2.28.0
  44285
  $ time git bisect start v2.28.0 v1.6.0^
  Bisecting: 22142 revisions left to test after this (roughly 15 steps)
  [565301e416] Sync with 2.1.2

  real  0m5.848s
  user  0m5.600s
  sys   0m0.252s

The difference is caused by one of the optimizations attempting to cut
down the runtime added in 1c4fea3a40 (git-rev-list --bisect:
optimization, 2007-03-21):

    Another small optimization is whenever we find a half-way commit
    (that is, a commit that can reach exactly half of the commits),
    we stop giving counts to remaining commits, as we will not find
    any better commit than we just found.

In this second 'git bisect start' command we happen to find a commit
exactly at the halfway point and can return early, but in the first
case there is no such commit, so we can't return early and end up
counting the number of reachable commits from all commits in the
good-bad range.

However, when we have thousands of commits it's not all that important
to find the _exact_ halfway point, a few commits more or less doesn't
make any real difference for the bisection.

So let's loosen the check in the halfway() helper to consider commits
within about 0.1% of the exact halfway point as halfway as well, and
rename the function to approx_halfway() accordingly.  This will allow
us to return early on a bigger good-bad range, even when there is no
commit exactly at the halfway point, thereby reducing the runtime of
the first command above considerably, from ~15s to 4.901s.
Furthermore, even if there is a commit exactly at the halfway point,
we might still stumble upon a commit within that 0.1% range before
finding the exact halfway point, allowing us to return a bit earlier,
slightly reducing the runtime of the second command from 5.848s to
5.058s.  Note that this change doesn't affect good-bad ranges
containing ~2000 commits or less, because that 0.1% tolerance becomes
zero due to integer arithmetic; however, if the range is that small
then counting the reachable commits for all commits is already fast
enough anyway.

Naturally, this will likely change which commits get picked at each
bisection step, and, in turn, might change how many bisection steps
are necessary to find the first bad commit.  If the number of
necessary bisection steps were to increase often, then this change
could backfire, because building and testing at each step might take
much longer than the time spared.  OTOH, if the number of steps were
to decrease, then it would be a double win.

So I ran some tests to see how often that happens: picked random good
and bad starting revisions at least 50k commits apart and a random
first bad commit in between in git.git, and used 'git bisect run git
merge-base --is-ancestor HEAD $first_bad_commit' to check the number
of necessary bisection steps.  After repeating all this 1000 times
both with and without this patch I found that:

  - 146 cases needed one more bisection step than before, 149 cases
    needed one less step, while in the remaining 705 cases the number
    of steps didn't change.  So the number of bisection steps does
    indeed change in a non-negligible number of cases, but it seems
    that the average number of steps doesn't change in the long run.

  - The first 'git bisect start' command got over 3x faster in 456
    cases, so this "no commit at the exact halfway point" case seems
    to be common enough to care about.

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-12 09:36:48 -08:00
René Scharfe
0795df4b9b bisect: clear flags in passed repository
69d2cfe6e8 (bisect.c: remove the_repository reference, 2018-11-10) kept
the implicit the_repository reference in clear_commit_marks_all, which
was made explicit by the previous commit (and which also renamed it to
repo_clear_commit_marks).  Replace it as well.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-10-31 10:46:34 -07:00
René Scharfe
cd8888452c object: allow clear_commit_marks_all to handle any repo
Allow callers to specify the repository to use.  Rename the function to
repo_clear_commit_marks to document its new scope.  No functional change
intended.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-10-31 10:46:34 -07:00
Pranit Bauva
517ecb3161 bisect--helper: reimplement bisect_next and bisect_auto_next shell functions in C
Reimplement the `bisect_next()` and the `bisect_auto_next()` shell functions
in C and add the subcommands to `git bisect--helper` to call them from
git-bisect.sh .

bisect_auto_next() function returns an enum bisect_error type as whole
`git bisect` can exit with an error code when bisect_next() does.

Return an error when `bisect_next()` fails, that fix a bug on shell script
version.

Using `--bisect-next` and `--bisect-auto-next` subcommands is a
temporary measure to port shell function to C so as to use the existing
test suite. As more functions are ported, `--bisect-auto-next`
subcommand will be retired and will be called by some other methods.

Mentored-by: Lars Schneider <larsxschneider@gmail.com>
Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Pranit Bauva <pranit.bauva@gmail.com>
Signed-off-by: Tanushree Tumane <tanushreetumane@gmail.com>
Signed-off-by: Miriam Rubio <mirucam@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-24 12:06:30 -07:00
Miriam Rubio
c7a7f48f4f bisect: call 'clear_commit_marks_all()' in 'bisect_next_all()'
As there can be other revision walks after bisect_next_all(),
let's add a call to a function to clear all the marks at the
end of bisect_next_all().

Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Miriam Rubio <mirucam@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-24 12:06:30 -07:00
Junio C Hamano
47f0f94bc7 Merge branch 'al/bisect-first-parent'
"git bisect" learns the "--first-parent" option to find the first
breakage along the first-parent chain.

* al/bisect-first-parent:
  bisect: combine args passed to find_bisection()
  bisect: introduce first-parent flag
  cmd_bisect__helper: defer parsing no-checkout flag
  rev-list: allow bisect and first-parent flags
  t6030: modernize "git bisect run" tests
2020-08-17 17:02:45 -07:00
Junio C Hamano
7d7f4e3a3e Merge branch 'rs/bisect-oid-to-hex-fix'
Code cleanup.

* rs/bisect-oid-to-hex-fix:
  bisect: use oid_to_hex_r() instead of memcpy()+oid_to_hex()
2020-08-10 10:24:01 -07:00
Aaron Lipman
ad464a4e84 bisect: combine args passed to find_bisection()
Now that find_bisection() accepts multiple boolean arguments, these may
be combined into a single unsigned integer in order to declutter some of
the code in bisect.c

Also, rename the existing "flags" bitfield to "commit_flags", to
explicitly differentiate it from the new "bisect_flags" bitfield.

Based-on-patch-by: Harald Nordgren <haraldnordgren@gmail.com>
Signed-off-by: Aaron Lipman <alipman88@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-07 15:13:03 -07:00
Aaron Lipman
e8861ffc20 bisect: introduce first-parent flag
Upon seeing a merge commit when bisecting, this option may be used to
follow only the first parent.

In detecting regressions introduced through the merging of a branch, the
merge commit will be identified as introduction of the bug and its
ancestors will be ignored.

This option is particularly useful in avoiding false positives when a
merged branch contained broken or non-buildable commits, but the merge
itself was OK.

Signed-off-by: Aaron Lipman <alipman88@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-07 15:13:03 -07:00
Aaron Lipman
be5fe2000d cmd_bisect__helper: defer parsing no-checkout flag
cmd_bisect__helper() is intended as a temporary shim layer serving as an
interface for git-bisect.sh. This function and git-bisect.sh should
eventually be replaced by a C implementation, cmd_bisect(), serving as
an entrypoint for all "git bisect ..." shell commands: cmd_bisect() will
only parse the first token following "git bisect", and dispatch the
remaining args to the appropriate function ["bisect_start()",
"bisect_next()", etc.].

Thus, cmd_bisect__helper() should not be responsible for parsing flags
like --no-checkout. Instead, let the --no-checkout flag remain in the
argv array, so it may be evaluated alongside the other options already
parsed by bisect_start().

Signed-off-by: Aaron Lipman <alipman88@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-07 15:13:03 -07:00
Aaron Lipman
0fe305a5d3 rev-list: allow bisect and first-parent flags
Add first_parent_only parameter to find_bisection(), removing the
barrier that prevented combining the --bisect and --first-parent flags
when using git rev-list

Based-on-patch-by: Tiago Botelho <tiagonbotelho@hotmail.com>
Signed-off-by: Aaron Lipman <alipman88@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-07 15:11:59 -07:00
René Scharfe
7d23ff818f bisect: use oid_to_hex_r() instead of memcpy()+oid_to_hex()
Write the hexadecimal object ID directly into the destination buffer
using oid_to_hex_r() instead of writing it into a static buffer first
using oid_to_hex() and then copying it from there using memcpy().
This is shorter, simpler and a bit more efficient.

Reviewed-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-02 13:02:52 -07:00
Jeff King
d70a9eb611 strvec: rename struct fields
The "argc" and "argv" names made sense when the struct was argv_array,
but now they're just confusing. Let's rename them to "nr" (which we use
for counts elsewhere) and "v" (which is rather terse, but reads well
when combined with typical variable names like "args.v").

Note that we have to update all of the callers immediately. Playing
tricks with the preprocessor is hard here, because we wouldn't want to
rewrite unrelated tokens.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-30 19:18:06 -07:00
Jeff King
f6d8942b1f strvec: fix indentation in renamed calls
Code which split an argv_array call across multiple lines, like:

  argv_array_pushl(&args, "one argument",
                   "another argument", "and more",
		   NULL);

was recently mechanically renamed to use strvec, which results in
mis-matched indentation like:

  strvec_pushl(&args, "one argument",
                   "another argument", "and more",
		   NULL);

Let's fix these up to align the arguments with the opening paren. I did
this manually by sifting through the results of:

  git jump grep 'strvec_.*,$'

and liberally applying my editor's auto-format. Most of the changes are
of the form shown above, though I also normalized a few that had
originally used a single-tab indentation (rather than our usual style of
aligning with the open paren). I also rewrapped a couple of obvious
cases (e.g., where previously too-long lines became short enough to fit
on one), but I wasn't aggressive about it. In cases broken to three or
more lines, the grouping of arguments is sometimes meaningful, and it
wasn't worth my time or reviewer time to ponder each case individually.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-28 15:02:18 -07:00
Jeff King
ef8d7ac42a strvec: convert more callers away from argv_array name
We eventually want to drop the argv_array name and just use strvec
consistently. There's no particular reason we have to do it all at once,
or care about interactions between converted and unconverted bits.
Because of our preprocessor compat layer, the names are interchangeable
to the compiler (so even a definition and declaration using different
names is OK).

This patch converts remaining files from the first half of the alphabet,
to keep the diff to a manageable size.

The conversion was done purely mechanically with:

  git ls-files '*.c' '*.h' |
  xargs perl -i -pe '
    s/ARGV_ARRAY/STRVEC/g;
    s/argv_array/strvec/g;
  '

and then selectively staging files with "git add '[abcdefghjkl]*'".
We'll deal with any indentation/style fallouts separately.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-28 15:02:18 -07:00
Jeff King
2745b6b450 quote: rename sq_dequote_to_argv_array to mention strvec
We want to eventually drop the use of the "argv_array" name in favor of
"strvec." Unlike most other uses of the name, this one is embedded in a
function name, so the definition and all of the callers need to be
updated at the same time.

We don't technically need to update the parameter types here (our
preprocessor compat macros make the two names interchangeable), but
let's do so to keep the site consistent for now.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-28 15:02:18 -07:00
Jeff King
dbbcd44fb4 strvec: rename files from argv-array to strvec
This requires updating #include lines across the code-base, but that's
all fairly mechanical, and was done with:

  git ls-files '*.c' '*.h' |
  xargs perl -i -pe 's/argv-array.h/strvec.h/'

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-28 15:02:17 -07:00
Jeff King
7383b25d76 bisect: stop referring to sha1_array
Our join_sha1_array_hex() function long ago switched to using an
oid_array; let's change the name to match.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-03-30 10:59:08 -07:00
Jeff King
fe299ec5ae oid_array: rename source file from sha1-array
We renamed the actual data structure in 910650d2f8 (Rename sha1_array to
oid_array, 2017-03-31), but the file is still called sha1-array. Besides
being slightly confusing, it makes it more annoying to grep for leftover
occurrences of "sha1" in various files, because the header is included
in so many places.

Let's complete the transition by renaming the source and header files
(and fixing up a few comment references).

I kept the "-" in the name, as that seems to be our style; cf.
fc1395f4a4 (sha1_file.c: rename to use dash in file name, 2018-04-10).
We also have oidmap.h and oidset.h without any punctuation, but those
are "struct oidmap" and "struct oidset" in the code. We _could_ make
this "oidarray" to match, but somehow it looks uglier to me because of
the length of "array" (plus it would be a very invasive patch for little
gain).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-03-30 10:59:08 -07:00
Pranit Bauva
6c69f22233 bisect: libify bisect_next_all
Since we want to get rid of git-bisect.sh, it would be necessary to
convert those exit() calls to return statements so that errors can be
reported.

Emulate try catch in C by converting `exit(<positive-value>)` to
`return <negative-value>`. Follow POSIX conventions to return
<negative-value> to indicate error.

All the functions calling `bisect_next_all()` are already able to
handle return values from it.

Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Pranit Bauva <pranit.bauva@gmail.com>
Signed-off-by: Tanushree Tumane <tanushreetumane@gmail.com>
Signed-off-by: Miriam Rubio <mirucam@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-19 09:37:15 -08:00
Pranit Bauva
9ec598e0d5 bisect: libify handle_bad_merge_base and its dependents
Since we want to get rid of git-bisect.sh, it would be necessary to
convert those exit() calls to return statements so that errors can be
reported.

Emulate try catch in C by converting `exit(<positive-value>)` to
`return <negative-value>`. Follow POSIX conventions to return
<negative-value> to indicate error.

Update all callers to handle the error returns.

Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Pranit Bauva <pranit.bauva@gmail.com>
Signed-off-by: Tanushree Tumane <tanushreetumane@gmail.com>
Signed-off-by: Miriam Rubio <mirucam@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-19 09:37:15 -08:00
Pranit Bauva
45b6370812 bisect: libify check_good_are_ancestors_of_bad and its dependents
Since we want to get rid of git-bisect.sh, it would be necessary to
convert those exit() calls to return statements so that errors can be
reported.

Emulate try catch in C by converting `exit(<positive-value>)` to
`return <negative-value>`. Follow POSIX conventions to return
<negative-value> to indicate error.

Code that turns BISECT_INTERNAL_SUCCESS_MERGE_BASE (-11)
 to BISECT_OK (0) from `check_good_are_ancestors_of_bad()` has been moved to
`cmd_bisect__helper()`.

Update all callers to handle the error returns.

Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Pranit Bauva <pranit.bauva@gmail.com>
Signed-off-by: Tanushree Tumane <tanushreetumane@gmail.com>
Signed-off-by: Miriam Rubio <mirucam@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-19 09:37:14 -08:00
Pranit Bauva
cdd4dc2d6a bisect: libify check_merge_bases and its dependents
Since we want to get rid of git-bisect.sh, it would be necessary to
convert those exit() calls to return statements so that errors can be
reported.

Emulate try catch in C by converting `exit(<positive-value>)` to
`return <negative-value>`. Follow POSIX conventions to return
<negative-value> to indicate error.

In `check_merge_bases()` there is an early success special case,
so we have introduced special error code
BISECT_INTERNAL_SUCCESS_MERGE_BASE (-11) which indicates early
success. This BISECT_INTERNAL_SUCCESS_MERGE_BASE is converted back
to BISECT_OK (0) in `check_good_are_ancestors_of_bad()`.

Update all callers to handle the error returns.

Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Pranit Bauva <pranit.bauva@gmail.com>
Signed-off-by: Tanushree Tumane <tanushreetumane@gmail.com>
Signed-off-by: Miriam Rubio <mirucam@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-19 09:37:14 -08:00
Pranit Bauva
e8e3ce6718 bisect: libify bisect_checkout
Since we want to get rid of git-bisect.sh, it would be necessary to
convert those exit() calls to return statements so that errors can be
reported.

Emulate try catch in C by converting `exit(<positive-value>)` to
`return <negative-value>`. Follow POSIX conventions to return
<negative-value> to indicate error.

Turn `exit()` to `return` calls in `bisect_checkout()`.
Changes related to return values have no bad side effects on the
code that calls `bisect_checkout()`.

Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Pranit Bauva <pranit.bauva@gmail.com>
Signed-off-by: Tanushree Tumane <tanushreetumane@gmail.com>
Signed-off-by: Miriam Rubio <mirucam@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-19 09:37:14 -08:00
Pranit Bauva
ce58b5d8b1 bisect: libify exit_if_skipped_commits to error_if_skipped* and its dependents
Since we want to get rid of git-bisect.sh, it would be necessary to
convert those exit() calls to return statements so that errors can be
reported.

Emulate try catch in C by converting `exit(<positive-value>)` to
`return <negative-value>`. Follow POSIX conventions to return
<negative-value> to indicate error.

Update all callers to handle the error returns.

Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Pranit Bauva <pranit.bauva@gmail.com>
Signed-off-by: Tanushree Tumane <tanushreetumane@gmail.com>
Signed-off-by: Miriam Rubio <mirucam@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-19 09:37:14 -08:00
Miriam Rubio
680e8a01e5 bisect: add enum to represent bisect returning codes
Since we want to get rid of git-bisect.sh, it would be necessary to
convert those exit() calls to return statements so that errors can be
reported.

Create an enum called `bisect_error` with the bisecting return codes
to use in `bisect.c` libification process.

Change bisect_next_all() to make it return this enum.

Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Miriam Rubio <mirucam@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-19 09:37:14 -08:00
Miriam Rubio
b8e3b2f339 bisect: use the standard 'if (!var)' way to check for 0
Instead of using 'var == 0' in an if condition, let's use '!var' and
make 'bisect.c' more consistent with the rest of the code.

Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Miriam Rubio <mirucam@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-19 09:37:14 -08:00
brian m. carlson
95518faac1 bisect: switch to using the_hash_algo
Instead of using GIT_SHA1_HEXSZ, use the_hash_algo so that the code is
hash size independent.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-08-19 15:04:58 -07:00
Jeff King
b02be8b901 bisect: make diff-tree output prettier
After completing a bisection, we print out the commit we found using an
internal version of diff-tree. The result is aesthetically lacking:

  - it shows a raw diff, which is generally less informative for human
    readers than "--stat --summary" (which we already decided was nice
    for humans in format-patch's output).

  - by not abbreviating hashes, the result is likely to wrap on most
    people's terminals

  - we don't use "-r", so if the commit touched files in a directory,
    you only get to see the top-level directory mentioned

  - we don't specify "--cc" or similar, so merges print nothing (not
    even the commit message!)

Even though bisect might be driven by scripts, there's no reason to
consider this part of the output as machine-readable (if anything, the
initial "$hash is the first bad commit" might be parsed, but we won't
touch that here). Let's make it prettier and more informative for a
human reading the output.

While we're tweaking the options, let's also switch to using the diff
"ui" config. If we're accepting that this is human-readable output, then
we should respect the user's options for how to display it.

Note that we have to touch a few tests in t6030. These check bisection
in a corrupted repository (it's missing a subtree). They didn't fail
with the previous code, because it didn't actually recurse far enough in
the diff to find the broken tree. But now we'll see the corruption and
complain.

Adjusting the tests to expect the die() is the best fix. We still
confirm that we're able to bisect within the broken repo. And we'll
still print "$hash is the first bad commit" as usual before dying;
showing that is a reasonable outcome in a corrupt repository (and was
what might happen already, if the root tree was corrupt).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-03-01 07:31:38 +09:00
Jeff King
40ae3d3eea bisect: fix internal diff-tree config loading
When we run our internal diff-tree to show the bisected commit, we call
init_revisions(), then load config, then setup_revisions(). But that
order is wrong: we copy the configured defaults into the rev_info struct
during the init_revisions step, so our config load wasn't actually doing
anything.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-03-01 07:31:37 +09:00
Jeff King
2008f29093 bisect: use string arguments to feed internal diff-tree
Commit e22278c0a0 (bisect: display first bad commit without forking a
new process, 2009-05-28) converted our external call to diff-tree to
an internal use of the log_tree_commit(). But rather than individually
setting options in the rev_info struct (and explaining in comments how
they map to command-line options), we can just pass the command-line
options to setup_revisions().

This is shorter, easier to change, and less likely to break if
revision.c internals change.

Note that we unconditionally set the output format to "raw". The
conditional in the original code didn't actually do anything useful,
since nobody had an opportunity to set the format to anything.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-03-01 07:31:35 +09:00
Junio C Hamano
5fda343321 Merge branch 'ds/push-sparse-tree-walk'
"git pack-objects" learned another algorithm to compute the set of
objects to send, that trades the resulting packfile off to save
traversal cost to favor small pushes.

* ds/push-sparse-tree-walk:
  pack-objects: create GIT_TEST_PACK_SPARSE
  pack-objects: create pack.useSparse setting
  revision: implement sparse algorithm
  list-objects: consume sparse tree walk
  revision: add mark_tree_uninteresting_sparse
2019-02-06 22:05:25 -08:00
Junio C Hamano
3434569fc2 Merge branch 'nd/style-opening-brace'
Code clean-up.

* nd/style-opening-brace:
  style: the opening '{' of a function is in a separate line
2019-01-18 13:49:52 -08:00
Derrick Stolee
4f6d26b167 list-objects: consume sparse tree walk
When creating a pack-file using 'git pack-objects --revs' we provide
a list of interesting and uninteresting commits. For example, a push
operation would make the local topic branch be interesting and the
known remote refs as uninteresting. We want to discover the set of
new objects to send to the server as a thin pack.

We walk these commits until we discover a frontier of commits such
that every commit walk starting at interesting commits ends in a root
commit or unintersting commit. We then need to discover which
non-commit objects are reachable from  uninteresting commits. This
commit walk is not changing during this series.

The mark_edges_uninteresting() method in list-objects.c iterates on
the commit list and does the following:

* If the commit is UNINTERSTING, then mark its root tree and every
  object it can reach as UNINTERESTING.

* If the commit is interesting, then mark the root tree of every
  UNINTERSTING parent (and all objects that tree can reach) as
  UNINTERSTING.

At the very end, we repeat the process on every commit directly
given to the revision walk from stdin. This helps ensure we properly
cover shallow commits that otherwise were not included in the
frontier.

The logic to recursively follow trees is in the
mark_tree_uninteresting() method in revision.c. The algorithm avoids
duplicate work by not recursing into trees that are already marked
UNINTERSTING.

Add a new 'sparse' option to the mark_edges_uninteresting() method
that performs this logic in a slightly different way. As we iterate
over the commits, we add all of the root trees to an oidset. Then,
call mark_trees_uninteresting_sparse() on that oidset. Note that we
include interesting trees in this process. The current implementation
of mark_trees_unintersting_sparse() will walk the same trees as
the old logic, but this will be replaced in a later change.

Add a '--sparse' flag in 'git pack-objects' to call this new logic.
Add a new test script t/t5322-pack-objects-sparse.sh that tests this
option. The tests currently demonstrate that the resulting object
list is the same as the old algorithm. This includes a case where
both algorithms pack an object that is not needed by a remote due to
limits on the explored set of trees. When the sparse algorithm is
changed in a later commit, we will add a test that demonstrates a
change of behavior in some cases.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-17 13:44:39 -08:00
Nguyễn Thái Ngọc Duy
3b3357626e style: the opening '{' of a function is in a separate line
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-12-10 15:41:09 +09:00
Nguyễn Thái Ngọc Duy
69d2cfe6e8 bisect.c: remove the_repository reference
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-12 14:50:05 +09:00
Junio C Hamano
11877b9ebe Merge branch 'nd/the-index'
Various codepaths in the core-ish part learn to work on an
arbitrary in-core index structure, not necessarily the default
instance "the_index".

* nd/the-index: (23 commits)
  revision.c: reduce implicit dependency the_repository
  revision.c: remove implicit dependency on the_index
  ws.c: remove implicit dependency on the_index
  tree-diff.c: remove implicit dependency on the_index
  submodule.c: remove implicit dependency on the_index
  line-range.c: remove implicit dependency on the_index
  userdiff.c: remove implicit dependency on the_index
  rerere.c: remove implicit dependency on the_index
  sha1-file.c: remove implicit dependency on the_index
  patch-ids.c: remove implicit dependency on the_index
  merge.c: remove implicit dependency on the_index
  merge-blobs.c: remove implicit dependency on the_index
  ll-merge.c: remove implicit dependency on the_index
  diff-lib.c: remove implicit dependency on the_index
  read-cache.c: remove implicit dependency on the_index
  diff.c: remove implicit dependency on the_index
  grep.c: remove implicit dependency on the_index
  diff.c: remove the_index dependency in textconv() functions
  blame.c: rename "repo" argument to "r"
  combine-diff.c: remove implicit dependency on the_index
  ...
2018-10-19 13:34:02 +09:00
Nguyễn Thái Ngọc Duy
2abf350385 revision.c: remove implicit dependency on the_index
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-09-21 09:51:19 -07:00
Junio C Hamano
1966cda6f4 Merge branch 'nd/bisect-show-list-fix'
Debugging aid update.

* nd/bisect-show-list-fix:
  bisect.c: make show_list() build again
2018-09-17 13:54:00 -07:00
Junio C Hamano
769af0fd9e Merge branch 'jk/cocci'
spatch transformation to replace boolean uses of !hashcmp() to
newly introduced oideq() is added, and applied, to regain
performance lost due to support of multiple hash algorithms.

* jk/cocci:
  show_dirstat: simplify same-content check
  read-cache: use oideq() in ce_compare functions
  convert hashmap comparison functions to oideq()
  convert "hashcmp() != 0" to "!hasheq()"
  convert "oidcmp() != 0" to "!oideq()"
  convert "hashcmp() == 0" to hasheq()
  convert "oidcmp() == 0" to oideq()
  introduce hasheq() and oideq()
  coccinelle: use <...> for function exclusion
2018-09-17 13:53:57 -07:00
Nguyễn Thái Ngọc Duy
b0eb92bbc2 bisect.c: make show_list() build again
This function only compiles when DEBUG_BISECT is 1, which is often not
the case. As a result there are two commits [1] [2] that break it but
the breakages went unnoticed because the code did not compile by
default. Update the function and include the new header file to make this
function build again.

In order to stop this from happening again, the function is now
compiled unconditionally but exits early unless DEBUG_BISECT is
non-zero. A smart compiler generates no extra code (not even a
function call). But even if it does not, this function does not seem
to be in a hot path that the extra cost becomes a big problem.

[1] bb408ac95d (bisect.c: use commit-slab for commit weight instead of
    commit->util - 2018-05-19)

[2] cbd53a2193 (object-store: move object access functions to
    object-store.h - 2018-05-15)

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-09-04 09:54:05 -07:00
Jeff King
9001dc2a74 convert "oidcmp() != 0" to "!oideq()"
This is the flip side of the previous two patches: checking
for a non-zero oidcmp() can be more strictly expressed as
inequality. Like those patches, we write "!= 0" in the
coccinelle transformation, which covers by isomorphism the
more common:

  if (oidcmp(E1, E2))

As with the previous two patches, this patch can be achieved
almost entirely by running "make coccicheck"; the only
differences are manual line-wrap fixes to match the original
code.

There is one thing to note for anybody replicating this,
though: coccinelle 1.0.4 seems to miss the case in
builtin/tag.c, even though it's basically the same as all
the others. Running with 1.0.7 does catch this, so
presumably it's just a coccinelle bug that was fixed in the
interim.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-29 11:32:49 -07:00
Jeff King
4a7e27e957 convert "oidcmp() == 0" to oideq()
Using the more restrictive oideq() should, in the long run,
give the compiler more opportunities to optimize these
callsites. For now, this conversion should be a complete
noop with respect to the generated code.

The result is also perhaps a little more readable, as it
avoids the "zero is equal" idiom. Since it's so prevalent in
C, I think seasoned programmers tend not to even notice it
anymore, but it can sometimes make for awkward double
negations (e.g., we can drop a few !!oidcmp() instances
here).

This patch was generated almost entirely by the included
coccinelle patch. This mechanical conversion should be
completely safe, because we check explicitly for cases where
oidcmp() is compared to 0, which is what oideq() is doing
under the hood. Note that we don't have to catch "!oidcmp()"
separately; coccinelle's standard isomorphisms make sure the
two are treated equivalently.

I say "almost" because I did hand-edit the coccinelle output
to fix up a few style violations (it mostly keeps the
original formatting, but sometimes unwraps long lines).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-29 11:32:49 -07:00
Derrick Stolee
6404355657 commit.h: remove method declarations
These methods are now declared in commit-reach.h. Remove them from
commit.h and add new include statements in all files that require these
declarations.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-07-20 15:38:54 -07:00
Stefan Beller
2122f6754c commit: add repository argument to lookup_commit_reference
Add a repository argument to allow callers of lookup_commit_reference
to be more specific about which repository to handle. This is a small
mechanical change; it doesn't change the implementation to handle
repositories other than the_repository yet.

As with the previous commits, use a macro to catch callers passing a
repository other than the_repository at compile time.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-29 10:43:39 -07:00
Nguyễn Thái Ngọc Duy
bb408ac95d bisect.c: use commit-slab for commit weight instead of commit->util
It's done so that commit->util can be removed. See more explanation in
the commit that removes commit->util.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-21 14:07:20 +09:00
Junio C Hamano
aa1c2b6804 Merge branch 'ys/bisect-object-id-missing-conversion-fix'
Code clean-up.

* ys/bisect-object-id-missing-conversion-fix:
  bisect: use oid_to_hex() for converting object_id hashes to hex strings
2018-04-10 16:28:24 +09:00
René Scharfe
14ced5562c bisect: use oid_to_hex() for converting object_id hashes to hex strings
Patch generated with Coccinelle and contrib/coccinelle/object_id.cocci.

Signed-off-by: Rene Scharfe <l.s.r@web.de>
Reviewed-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-03-25 09:48:05 -07:00
brian m. carlson
b4f5aca40e sha1_file: convert read_sha1_file to struct object_id
Convert read_sha1_file to take a pointer to struct object_id and rename
it read_object_file.  Do the same for read_sha1_file_extended.

Convert one use in grep.c to use the new function without any other code
change, since the pointer being passed is a void pointer that is already
initialized with a pointer to struct object_id.  Update the declaration
and definitions of the modified functions, and apply the following
semantic patch to convert the remaining callers:

@@
expression E1, E2, E3;
@@
- read_sha1_file(E1.hash, E2, E3)
+ read_object_file(&E1, E2, E3)

@@
expression E1, E2, E3;
@@
- read_sha1_file(E1->hash, E2, E3)
+ read_object_file(E1, E2, E3)

@@
expression E1, E2, E3, E4;
@@
- read_sha1_file_extended(E1.hash, E2, E3, E4)
+ read_object_file_extended(&E1, E2, E3, E4)

@@
expression E1, E2, E3, E4;
@@
- read_sha1_file_extended(E1->hash, E2, E3, E4)
+ read_object_file_extended(E1, E2, E3, E4)

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-03-14 09:23:50 -07:00