Commit Graph

65095 Commits

Author SHA1 Message Date
Ævar Arnfjörð Bjarmason
1fd2aa543d grep.h: remove unused grep_threads_ok() declaration
This function was removed in 0579f91dd7 (grep: enable threading with
-p and -W using lazy attribute lookup, 2011-12-12), but not its
corresponding *.h declaration.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-01 14:39:46 -07:00
Ævar Arnfjörð Bjarmason
f787ebd51c builtin.h: remove cmd_tar_tree() declaration
The cmd_tar_tree() function itself was removed in
925ceccf05 (tar-tree: remove deprecated command, 2013-11-10).

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-01 14:39:46 -07:00
Ævar Arnfjörð Bjarmason
0000e81811 builtin/remote.c: add and use SHOW_INFO_INIT
In the preceding commit we introduced REF_STATES_INIT, but did not
change the "struct show_info" to have a corresponding
initializer. Let's do that, and make it use "REF_STATES_INIT" and
"STRING_LIST_INIT_DUP", doing that requires changing "list" and
"states" away from being pointers.

The resulting end-state is simpler since we omit the local "info_list"
and "states" variables in show() as well as the memset().

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-01 14:22:51 -07:00
Ævar Arnfjörð Bjarmason
0bc7787ca9 builtin/remote.c: add and use a REF_STATES_INIT
Use a new REF_STATES_INIT designated initializer instead of assigning
to the "strdup_strings" member of the previously memzero()'d version
of this struct.

The pattern of assigning to "strdup_strings" dates back to
211c89682e (Make git-remote a builtin, 2008-02-29) (when it was
"strdup_paths"), i.e. long before we used anything like our current
established *_INIT patterns consistently.

Then in e61e0cc6b7 (builtin-remote: teach show to display remote
HEAD, 2009-02-25) and e5dcbfd9ab (builtin-remote: new show output
style for push refspecs, 2009-02-25) we added some more of these.

As it turns out we only initialized this struct three times, all the
other uses were of pointers to those initialized structs. So let's
initialize it in those three places, skip the memset(), and pass those
structs down appropriately.

This would be a behavior change if we had codepaths that relied say on
implicitly having had "new_refs" initialized to STRING_LIST_INIT_NODUP
with the memset(), but only set the "strdup_strings" on some other
struct, but then called string_list_append() on "new_refs". There
isn't any such codepath, all of the late assignments to
"strdup_strings" assigned to those structs that we'd use for those
codepaths.

So just initializing them all up-front makes for easier to understand
code, i.e. in the pre-image it looked as though we had that tricky
edge case, but we didn't.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-01 14:22:51 -07:00
Ævar Arnfjörð Bjarmason
73ee449bbf urlmatch.[ch]: add and use URLMATCH_CONFIG_INIT
Change the initialization pattern of "struct urlmatch_config" to use
an *_INIT macro and designated initializers. Right now there's no
other "struct" member of "struct urlmatch_config" which would require
its own *_INIT, but it's good practice not to assume that. Let's also
change this to a designated initializer while we're at it.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-01 14:22:51 -07:00
René Scharfe
afc72b5d3a mergesort: use ranks stack
The bottom-up mergesort implementation needs to skip through sublists a
lot.  A recursive version could avoid that, but would require log2(n)
stack frames.  Explicitly manage a stack of sorted sublists of various
lengths instead to avoid fast-forwarding while also keeping a lid on
memory usage.

While this patch was developed independently, a ranks stack is also used
in https://github.com/mono/mono/blob/master/mono/eglib/sort.frag.h by
the Mono project.

The idea is to keep slots for log2(n_max) sorted sublists, one for each
power of 2.  Such a construct can accommodate lists of any length up to
n_max.  Since there is a known maximum number of items (effectively
SIZE_MAX), we can preallocate the whole rank stack.

We add items one by one, which is akin to incrementing a binary number.
Make use of that by keeping track of the number of items and check bits
in it instead of checking for NULL in the rank stack when checking if a
sublist of a certain rank exists, in order to avoid memory accesses.

The first item can go into the empty first slot as a sublist of length
2^0.  The second one needs to be merged with the previous sublist and
the result goes into the empty second slot as a sublist of length 2^1.
The third one goes into vacated first slot and so on.  At the end we
merge all the sublists to get the result.

The new version still performs a stable sort by making sure to put items
seen earlier first when the compare function indicates equality.  That's
done by preferring items from sublists with a higher rank.

The new merge function also tries to minimize the number of operations.
Like blame.c::blame_merge(), the function doesn't set the next pointer
if it already points to the right item, and it exits when it reaches the
end of one of the two sublists that it's given.  The old code couldn't
do the latter because it kept all items in a single list.

The number of comparisons stays the same, though.  Here's example output
of "test-tool mergesort test" for the rand distributions with the most
number of comparisons with the ranks stack:

   $ t/helper/test-tool mergesort test | awk '
       NR > 1 && $1 != "rand" {next}
       $7 > max[$3] {max[$3] = $7; line[$3] = $0}
       END {for (n in line) print line[n]}
   '

distribut mode                    n        m get_next set_next  compare verdict
rand      copy                  100       32      669      420      569 OK
rand      dither               1023       64     9997     5396     8974 OK
rand      dither               1024      512    10007     6159     8983 OK
rand      dither               1025      256    10993     5988     9968 OK

Here are the differences to the results without this patch:

distribut mode                    n        m get_next set_next  compare
rand      copy                  100       32     -515     -280        0
rand      dither               1023       64    -6376    -4834        0
rand      dither               1024      512    -6377    -4081        0
rand      dither               1025      256    -7461    -5287        0

The numbers of get_next and set_next calls are reduced significantly.

NB: These winners are different than the ones shown in the patch that
introduced the unriffle mode because the addition of the unriffle_skewed
mode in between changed the consumption of rand() values.

Here are the distributions with the most comparisons overall with the
ranks stack:

   $ t/helper/test-tool mergesort test | awk '
       $7 > max[$3] {max[$3] = $7; line[$3] = $0}
       END {for (n in line) print line[n]}
   '

distribut mode                    n        m get_next set_next  compare verdict
sawtooth  unriffle_skewed       100      128      689      632      589 OK
sawtooth  unriffle_skewed      1023     1024    10230    10220     9207 OK
sawtooth  unriffle             1024     1024    10241    10240     9217 OK
sawtooth  unriffle_skewed      1025     2048    11266    10242    10241 OK

And here the differences to before:

distribut mode                    n        m get_next set_next  compare
sawtooth  unriffle_skewed       100      128     -495      -68        0
sawtooth  unriffle_skewed      1023     1024    -6143      -10        0
sawtooth  unriffle             1024     1024    -6143        0        0
sawtooth  unriffle_skewed      1025     2048    -7188    -1033        0

We get a similar reduction of get_next calls here, but only a slight
reduction of set_next calls, if at all.

And here are the results of p0071-sort.sh before:

0071.12: llist_mergesort() unsorted    0.36(0.33+0.01)
0071.14: llist_mergesort() sorted      0.15(0.13+0.01)
0071.16: llist_mergesort() reversed    0.16(0.14+0.01)

... and here the ones with this patch:

0071.12: llist_mergesort() unsorted    0.24(0.22+0.01)
0071.14: llist_mergesort() sorted      0.12(0.10+0.01)
0071.16: llist_mergesort() reversed    0.12(0.10+0.01)

NB: We can't use t/perf/run to compare revisions in one run because it
uses the test-tool from the worktree, not from the revisions being
tested.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-01 12:43:09 -07:00
René Scharfe
40bc872adb p0071: test performance of llist_mergesort()
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-01 12:43:09 -07:00
René Scharfe
84edc40676 p0071: measure sorting of already sorted and reversed files
Check if sorting takes advantage of already sorted or reversed content,
or if that corner case actually decreases performance, like it would for
a simplistic quicksort implementation.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-01 12:43:09 -07:00
René Scharfe
f1ed4ce9e3 test-mergesort: add unriffle_skewed mode
Add a mode that turns a sorted list into adversarial input for a
bottom-up mergesort implementation that doubles the length of sorted
sublists at each level -- like our llist_mergesort().

While unriffle mode splits the list in half at each recursion step,
unriffle_skewed splits it into 2^l items and the rest, with 2^l being
the highest power of two smaller than the number of items and thus
2^l >= rest.  The rest is unriffled with the tail of the first half to
require a merge to compare the maximum number of elements.

It complements the unriffle mode, which targets balanced merges.  If
the number of elements is a power of two then both actually produce the
same result, as 2^l == rest == n/2 at each recursion step in that case.

Here are the results:

   $ t/helper/test-tool mergesort test | awk '
      $7 > max[$3] {max[$3] = $7; line[$3] = $0}
      END {for (n in line) print line[n]}
   '

distribut mode                    n        m get_next set_next  compare verdict
sawtooth  unriffle_skewed       100      128     1184      700      589 OK
sawtooth  unriffle_skewed      1023     1024    16373    10230     9207 OK
sawtooth  unriffle             1024     1024    16384    10240     9217 OK
sawtooth  unriffle_skewed      1025     2048    18454    11275    10241 OK

The sawtooth distribution with m>=n produces a sorted list and
unriffle_skewed mode turns it into adversarial input for unbalanced
merges, which it wins in all cases except for n=1024 -- the resulting
list is the same, but unriffle is tested before unriffle_skewed, so its
result is selected by the AWK script.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-01 12:43:09 -07:00
René Scharfe
1aa589922b test-mergesort: add unriffle mode
Add a mode that turns sorted items into adversarial input for mergesort.
Do that by running mergesort in reverse and rearranging the items in
such a way that each merge needs the maximum number of operations to
undo it.

To riffle is a card shuffling technique and involves splitting a deck
into two and then to interleave them.  A perfect riffle takes one card
from each half in turn.  That's similar to the most expensive merge,
which has to take one item from each sublist in turn, which requires the
maximum number of comparisons (n-1).

So unriffle does that in reverse, i.e. it generates the first sublist
out of the items at even indexes and the second sublist out of the items
at odd indexes, without changing their order in any other way.  Done
recursively until we reach the trivial sublist length of one, this
twists the list into an order that requires the maximum effort for
mergesort to untangle.

As a baseline, here are the rand distributions with the highest number
of comparisons from "test-tool mergesort test":

   $ t/helper/test-tool mergesort test | awk '
      NR > 1 && $1 != "rand" {next}
      $7 > max[$3] {max[$3] = $7; line[$3] = $0}
      END {for (n in line) print line[n]}
   '

distribut mode                    n        m get_next set_next  compare verdict
rand      copy                  100       32     1184      700      569 OK
rand      reverse_1st_half     1023      256    16373    10230     8976 OK
rand      reverse_1st_half     1024      512    16384    10240     8993 OK
rand      dither               1025       64    18454    11275     9970 OK

And here are the most expensive ones overall:

   $ t/helper/test-tool mergesort test | awk '
      $7 > max[$3] {max[$3] = $7; line[$3] = $0}
      END {for (n in line) print line[n]}
   '

distribut mode                    n        m get_next set_next  compare verdict
stagger   reverse               100       64     1184      700      580 OK
sawtooth  unriffle             1023     1024    16373    10230     9179 OK
sawtooth  unriffle             1024     1024    16384    10240     9217 OK
stagger   unriffle             1025     2048    18454    11275    10241 OK

The sawtooth distribution with m>=n generates a sorted list.  The
unriffle mode is designed to turn that into adversarial input for
mergesort, and that checks out for n=1023 and n=1024, where it produces
the list that requires the most comparisons.

Item counts that are not powers of two have other winners, and that's
because unriffle recursively splits lists into equal-sized halves, while
llist_mergesort() splits them into the biggest power of two smaller than
n and the rest, e.g. for n=1025 it sorts the first 1024 separately and
finally merges them to the last item.

So unriffle mode works as designed for the intended use case, but to
consistently generate adversarial input for unbalanced merges we need
something else.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-01 12:43:08 -07:00
René Scharfe
0cecb75531 test-mergesort: add generate subcommand
Add a subcommand for printing test data.  It can be used to generate
special test cases and feed them into the sort subcommand or sort(1) for
performance measurements.  It may also be useful to illustrate the
effect of distributions, modes and their parameters.

It generates n integers with the specified distribution and its
distribution-specific parameter m.  E.g. m is the maximum value for
the plateau distribution and the length and height of individual teeth
of the sawtooth distribution.

The generated values are printed as zero-padded eight-digit hexadecimal
numbers to make sure alphabetic and numeric order are the same.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-01 12:43:08 -07:00
René Scharfe
e031e9719d test-mergesort: add test subcommand
Adapt the qsort certification program from "Engineering a Sort Function"
by Bentley and McIlroy for testing our linked list sort function.  It
generates several lists with various distribution patterns and counts
the number of operations llist_mergesort() needs to order them.  It
compares the result to the output of a trusted sort function (qsort(1))
and also checks if the sort is stable.

Also add a test script that makes use of the new subcommand.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-01 12:43:08 -07:00
René Scharfe
d536a71169 test-mergesort: add sort subcommand
Give the code for sorting a text file its own sub-command.  This allows
extending the helper, which we'll do in the following patches.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-01 12:43:08 -07:00
René Scharfe
2e6701017e test-mergesort: use strbuf_getline()
Strip line ending characters to make sure empty lines are sorted like
sort(1) does.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-01 12:43:08 -07:00
David Aguilar
28c10ecbfc difftool: add a missing space to the run_dir_diff() comments
Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-30 18:48:51 -07:00
David Aguilar
8e2af8f0db difftool: remove an unnecessary call to strbuf_release()
The `buf` strbuf is reused again later in the same function, so there
is no benefit to calling strbuf_release(). The subsequent usage is
already using strbuf_reset() to reset the buffer, so releasing it
early is only going to lead to a wasteful reallocation.

Remove the early call to strbuf_release(). The same strbuf is already
cleaned up in the "finish:" section so nothing is leaked, either.

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-30 18:48:51 -07:00
David Aguilar
2255c80c91 difftool: refactor dir-diff to write files using helper functions
Add a helpers function to handle the unlinking and writing
of the dir-diff submodule and symlink stand-in files.

Use the helpers to implement the guts of the hashmap loops.
This eliminate duplicate code and safeguards the submodules
hashmap loop against the symlink-chasing behavior that 5bafb3576a
(difftool: fix symlink-file writing in dir-diff mode, 2021-09-22)
addressed.

The submodules loop should not strictly require the unlink() call that
this is introducing to them, but it does not necessarily hurt them
either beyond the cost of the extra unlink().

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-30 18:48:51 -07:00
David Aguilar
4ac9f15492 difftool: create a tmpdir path without repeated slashes
The paths generated by difftool are passed to user-facing diff tools.
Using paths with repeated slashes in them is a cosmetic blemish that
is exposed to users and can be avoided.

Use a strbuf to create the buffer used for the dir-diff tmpdir.
Strip trailing slashes from the value read from TMPDIR to avoid
repeated slashes in the generated paths.

Adjust the error handling to avoid leaking strbufs and to avoid
returning -1 to cmd_main().

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-30 18:48:51 -07:00
Hamza Mahfooz
3f566c4e69 grep: refactor next_match() and match_one_pattern() for external use
These changes are made in preparation of, the colorization support for the
"git log" subcommands that, rely on regex functionality (i.e. "--author",
"--committer" and "--grep"). These changes are necessary primarily because
match_one_pattern() expects header lines to be prefixed, however, in
pretty, the prefixes are stripped from the lines because the name-email
pairs need to go through additional parsing, before they can be printed and
because next_match() doesn't handle the case of
"ctx == GREP_CONTEXT_HEAD" at all. So, teach next_match() how to handle the
new case and move match_one_pattern()'s core logic to
headerless_match_one_pattern() while preserving match_one_pattern()'s uses
that depend on the additional processing.

Signed-off-by: Hamza Mahfooz <someguy@effective-light.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-29 13:23:11 -07:00
Matheus Tavares
45bde58ef8 grep: demonstrate bug with textconv attributes and submodules
In some circumstances, "git grep --textconv --recurse-submodules"
ignores the textconv attributes from the submodules and erroneously
applies the attributes defined in the superproject on the submodules'
files. The textconv cache is also saved on the superproject, even for
submodule objects.

A fix for these problems will probably require at least three changes:

- Some textconv and attributes functions (as well as their callees) will
  have to be adjusted to work with arbitrary repositories. Note that
  "fill_textconv()", for example, already receives a "struct repository"
  but it writes the textconv cache using "write_loose_object()", which
  implicitly works on "the_repository".

- grep.c functions will have to call textconv/userdiff routines passing
  the "repo" field from "struct grep_source" instead of the one from
  "struct grep_opt". The latter always points to "the_repository" on
  "git grep" executions (see its initialization in builtin/grep.c), but
  the former points to the correct repository that each source (an
  object, file, or buffer) comes from.

- "userdiff_find_by_path()" might need to use a different attributes
  stack for each repository it works on or reset its internal static
  stack when the repository is changed throughout the calls.

For now, let's add some tests to demonstrate these problems, and also
update a NEEDSWORK comment in grep.h that mentions this bug to reference
the added tests.

Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-29 13:19:38 -07:00
Taylor Blau
6d08b9d4ca builtin/repack.c: make largest pack preferred
When repacking into a geometric series and writing a multi-pack bitmap,
it is beneficial to have the largest resulting pack be the preferred
object source in the bitmap's MIDX, since selecting the large packs can
lead to fewer broken delta chains and better compression.

Teach 'git repack' to identify this pack and pass it to the MIDX write
machinery in order to mark it as preferred.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-28 21:20:56 -07:00
Taylor Blau
1d89d88d37 builtin/repack.c: support writing a MIDX while repacking
Teach `git repack` a new `--write-midx` option for callers that wish to
persist a multi-pack index in their repository while repacking.

There are two existing alternatives to this new flag, but they don't
cover our particular use-case. These alternatives are:

  - Call 'git multi-pack-index write' after running 'git repack', or

  - Set 'GIT_TEST_MULTI_PACK_INDEX=1' in your environment when running
    'git repack'.

The former works, but introduces a gap in bitmap coverage between
repacking and writing a new MIDX (since the repack may have deleted a
pack included in the existing MIDX, invalidating it altogether).

Setting the 'GIT_TEST_' environment variable is obviously unsupported.
In fact, even if it were supported officially, it still wouldn't work,
because it generates the MIDX *after* redundant packs have been dropped,
leading to the same issue as above.

Introduce a new option which eliminates this race by teaching `git
repack` to generate the MIDX at the critical point: after the new packs
have been written and moved into place, but before the redundant packs
have been removed.

This option is compatible with `git repack`'s '--bitmap' option (it
changes the interpretation to be: "write a bitmap corresponding to the
MIDX after one has been generated").

There is a little bit of additional noise in the patch below to avoid
repeating ourselves when selecting which packs to delete. Instead of a
single loop as before (where we iterate over 'existing_packs', decide if
a pack is worth deleting, and if so, delete it), we have two loops (the
first where we decide which ones are worth deleting, and the second
where we actually do the deleting). This makes it so we have a single
check we can make consistently when (1) telling the MIDX which packs we
want to exclude, and (2) actually unlinking the redundant packs.

There is also a tiny change to short-circuit the body of
write_midx_included_packs() when no packs remain in the case of an empty
repository. The MIDX code does not handle this, so avoid trying to
generate a MIDX covering zero packs in the first place.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-28 21:20:56 -07:00
Taylor Blau
5f18e31f46 builtin/repack.c: extract showing progress to a variable
We only ask whether stderr is a tty before calling
'prune_packed_objects()', but the subsequent patch will add another use.

Extract this check into a variable so that both can use it without
having to call 'isatty()' twice.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-28 21:20:56 -07:00
Taylor Blau
a169166d2b builtin/repack.c: rename variables that deal with non-kept packs
The new variable `existing_kept_packs` (and corresponding parameter
`fname_kept_list`) added by the previous patch make it seem like
`existing_packs` and `fname_list` are each subsets of the other two
respectively.

In reality, each pair is disjoint: one stores the packs without .keep
files, and the other stores the packs with .keep files. Rename each to
more clearly reflect this.

Suggested-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-28 21:20:56 -07:00
Taylor Blau
90f838bc36 builtin/repack.c: keep track of existing packs unconditionally
In order to be able to write a multi-pack index during repacking, `git
repack` must keep track of which packs it wants to write into the MIDX.
This set is the union of existing packs which will not be deleted,
new pack(s) generated as a result of the repack, and .keep packs.

Prior to this patch, `git repack` populated the list of existing packs
only when repacking all-into-one (i.e., with `-A` or `-a`), but we will
soon need to know this list when repacking when writing a MIDX without
a-i-o.

Populate the list of existing packs unconditionally, and guard removing
packs from that list only when repacking a-i-o.

Additionally, keep track of filenames of kept packs separately, since
this, too, will be used in an upcoming patch.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-28 21:20:56 -07:00
Taylor Blau
08944d1c22 midx: preliminary support for --refs-snapshot
To figure out which commits we can write a bitmap for, the multi-pack
index/bitmap code does a reachability traversal, marking any commit
which can be found in the MIDX as eligible to receive a bitmap.

This approach will cause a problem when multi-pack bitmaps are able to
be generated from `git repack`, since the reference tips can change
during the repack. Even though we ignore commits that don't exist in
the MIDX (when doing a scan of the ref tips), it's possible that a
commit in the MIDX reaches something that isn't.

This can happen when a multi-pack index contains some pack which refers
to loose objects (e.g., if a pack was pushed after starting the repack
but before generating the MIDX which depends on an object which is
stored as loose in the repository, and by definition isn't included in
the multi-pack index).

By taking a snapshot of the references before we start repacking, we can
close that race window. In the above scenario (where we have a packed
object pointing at a loose one), we'll either (a) take a snapshot of the
references before seeing the packed one, or (b) take it after, at which
point we can guarantee that the loose object will be packed and included
in the MIDX.

This patch does just that. It writes a temporary "reference snapshot",
which is a list of OIDs that are at the ref tips before writing a
multi-pack bitmap. References that are "preferred" (i.e,. are a suffix
of at least one value of the 'pack.preferBitmapTips' configuration) are
marked with a special '+'.

The format is simple: one line per commit at each tip, with an optional
'+' at the beginning (for preferred references, as described above).

When provided, the reference snapshot is used to drive bitmap selection
instead of the MIDX code doing its own traversal. When it isn't
provided, the usual traversal takes place instead.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-28 21:20:56 -07:00
Taylor Blau
6fb22ca463 builtin/multi-pack-index.c: support --stdin-packs mode
To power a new `--write-midx` mode, `git repack` will want to write a
multi-pack index containing a certain set of packs in the repository.

This new option will be used by `git repack` to write a MIDX which
contains only the packs which will survive after the repack (that is, it
will exclude any packs which are about to be deleted).

This patch effectively exposes the function implemented in the previous
commit via the `git multi-pack-index` builtin. An alternative approach
would have been to call that function from the `git repack` builtin
directly, but this introduces awkward problems around closing and
reopening the object store, so the MIDX will be written out-of-process.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-28 21:20:55 -07:00
Taylor Blau
56d863e979 midx: expose write_midx_file_only() publicly
Expose a variant of the write_midx_file() function which ignores packs
that aren't included in an explicit "allow" list.

This will be used in an upcoming patch to power a new `--stdin-packs`
mode of `git multi-pack-index write` for callers that only want to
include certain packs in a MIDX (and ignore any packs which may have
happened to enter the repository independently, e.g., from pushes).

Those patches will provide test coverage for this new function.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-28 21:20:55 -07:00
Carlo Marcelo Arenas Belón
ebd2e4a13a Makefile: restrict -Wpedantic and -Wno-pedantic-ms-format better
6a8cbc41ba (developer: enable pedantic by default, 2021-09-03)
enables pedantic mode in as many compilers as possible to help gather
feedback on future tightening, so lets do so.

-Wpedantic is missing in some really old gcc 4 versions so lets restrict
it to gcc5 and clang4 (it does work in clang3 AFAIK, but it will be
unlikely that a developer will use such an old compiler anyway).

MinGW gcc is the only one which has -Wno-pedantic-ms-format, and while
that is available also in older compilers, the Windows SDK provides gcc10
so lets aim for that.

Note that in order to target the flag to only Windows, additional changes
were needed in config.mak.uname to propagate the OS detection which also
did some minor refactoring, but which is functionaly equivalent.

Helped-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-28 21:15:53 -07:00
Ævar Arnfjörð Bjarmason
3b723f722d parse-options.h: move PARSE_OPT_SHELL_EVAL between enums
Fix a bad landmine of a bug which has been with us ever since
PARSE_OPT_SHELL_EVAL was added in 47e9cd28f8 (parseopt: wrap
rev-parse --parseopt usage for eval consumption, 2010-06-12).

It's an argument to parse_options() and should therefore be in "enum
parse_opt_flags", but it was added to the per-option "enum
parse_opt_option_flags" by mistake.

Therefore as soon as we'd have an enum member in the former that
reached its value of "1 << 8" we'd run into a seemingly bizarre bug
where that new option would turn on the unrelated PARSE_OPT_SHELL_EVAL
in "git rev-parse --parseopt" by proxy.

I manually checked that no other enum members suffered from such
overlap, by setting the values to non-overlapping values, and making
the relevant codepaths BUG() out if the given value was above/below
the expected (excluding flags=0 in the case of "enum
parse_opt_flags").

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-28 16:50:42 -07:00
Orgad Shaneh
6ffb990dc4 doc: fix capitalization in "git status --porcelain=v2" description
The summary line had xy, while the description (and other sub-sections)
has XY.

Signed-off-by: Orgad Shaneh <orgads@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-28 16:29:04 -07:00
Junio C Hamano
b6b210c5e1 Merge branch 'jk/ref-paranoia' into jt/no-abuse-alternate-odb-for-submodules
* jk/ref-paranoia: (71 commits)
  refs: drop "broken" flag from for_each_fullref_in()
  ref-filter: drop broken-ref code entirely
  ref-filter: stop setting FILTER_REFS_INCLUDE_BROKEN
  repack, prune: drop GIT_REF_PARANOIA settings
  refs: turn on GIT_REF_PARANOIA by default
  refs: omit dangling symrefs when using GIT_REF_PARANOIA
  refs: add DO_FOR_EACH_OMIT_DANGLING_SYMREFS flag
  refs-internal.h: reorganize DO_FOR_EACH_* flag documentation
  refs-internal.h: move DO_FOR_EACH_* flags next to each other
  t5312: be more assertive about command failure
  t5312: test non-destructive repack
  t5312: create bogus ref as necessary
  t5312: drop "verbose" helper
  t5600: provide detached HEAD for corruption failures
  t5516: don't use HEAD ref for invalid ref-deletion tests
  t7900: clean up some more broken refs
  The eighth batch
  t0000: avoid masking git exit value through pipes
  tree-diff: fix leak when not HAVE_ALLOCA_H
  pack-revindex.h: correct the time complexity descriptions
  ...
2021-09-28 15:15:42 -07:00
Ævar Arnfjörð Bjarmason
750036c8f7 refs/ref-cache.[ch]: remove "incomplete" from create_dir_entry()
Remove the now-unused "incomplete" parameter from create_dir_entry(),
all its callers specify it as "1", so let's drop the "incomplete=0"
case. The last caller to use it was search_for_subdir(), but that code
was removed in the preceding commit.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-28 15:12:04 -07:00
Ævar Arnfjörð Bjarmason
5e4546d599 refs/ref-cache.c: remove "mkdir" parameter from find_containing_dir()
Remove the "mkdir" parameter from the find_containing_dir() function,
the add_ref_entry() function removed in the preceding commit was its
last user.

Since "mkdir" is always "0" we can also remove the parameter from
search_for_subdir(), which in turn means that we can delete most of
that function.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-28 15:12:04 -07:00
Ævar Arnfjörð Bjarmason
6a99fa2e9e refs/ref-cache.[ch]: remove unused add_ref_entry()
This function has not been used since 9dd389f3d8 (packed_ref_store:
get rid of the `ref_cache` entirely, 2017-09-25).

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-28 15:12:04 -07:00
Ævar Arnfjörð Bjarmason
34e8a20d76 refs/ref-cache.[ch]: remove unused remove_entry_from_dir()
This function was missed in 9939b33d6a (packed-backend: rip out some
now-unused code, 2017-09-08), and has been orphaned since then. Let's
delete it.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-28 15:12:04 -07:00
Ævar Arnfjörð Bjarmason
98961e42f0 refs.[ch]: remove unused ref_storage_backend_exists()
This function was added in 3dce444f17 (refs: add a backend method
structure, 2016-09-04), but has never been used by anything. The only
caller that might care uses find_ref_storage_backend() directly.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-28 15:12:04 -07:00
Ævar Arnfjörð Bjarmason
73c5f67071 config.c: remove unused git_config_key_is_valid()
The git_config_key_is_valid() function got left behind in a
refactoring in a9bcf6586d (alias: use the early config machinery to
expand aliases, 2017-06-14),

It previously had two users when it was added in 9e9de18f1a (config:
silence warnings for command names with invalid keys, 2015-08-24), and
after 6a1e1bc0a1 (pager: use callbacks instead of configset,
2016-09-12) only one remained.

By removing it we can get rid of the "quiet" branches in this
function, as well as cases where "store_key" is NULL, for which there
are no other users.

Out of the 5 callers of git_config_parse_key() only one needs to pass
a non-NULL "size_t *baselen_", so we could remove the third parameter
from the public interface. I did not find that potential
simplification to be worthwhile.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-28 14:54:15 -07:00
Ævar Arnfjörð Bjarmason
abf897bacd string-list.[ch]: remove string_list_init() compatibility function
Remove this function left over to accommodate in-flight changes, see
770fedaf9f (string-list.[ch]: add a string_list_init_{nodup,dup}(),
2021-07-01) for the recent change to add
"string_list_init_{nodup,dup}()" initializers.

There was only one user of the API left in remote-curl.c. I don't know
why I didn't include this change to remote-curl.c in
bc40dfb10a (string-list.h users: change to use *_{nodup,dup}(),
2021-07-01), perhaps I just missed it.

In any case, let's change that one user to use the new API, as of
writing this there are no in-flight changes that use, so this seems
like a good time to drop this before we get any new users of this
compatibility API.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-28 14:43:38 -07:00
Junio C Hamano
cefe983a32 The ninth batch
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-28 13:06:53 -07:00
Junio C Hamano
45d141a1dd Merge branch 'en/typofixes'
Typofixes.

* en/typofixes:
  merge-ort: fix completely wrong comment
  trace2.h: fix trivial comment typo
2021-09-28 13:06:53 -07:00
Junio C Hamano
3d875f96f1 Merge branch 'cb/unicode-14'
The unicode character width table (used for output alignment) has
been updated.

* cb/unicode-14:
  unicode: update the width tables to Unicode 14
2021-09-28 13:06:53 -07:00
Junio C Hamano
bb1677fc29 Merge branch 'jk/reduce-malloc-in-v2-servers'
Code cleanup to limit memory consumption and tighten protocol
message parsing.

* jk/reduce-malloc-in-v2-servers:
  ls-refs: reject unknown arguments
  serve: reject commands used as capabilities
  serve: reject bogus v2 "command=ls-refs=foo"
  docs/protocol-v2: clarify some ls-refs ref-prefix details
  ls-refs: ignore very long ref-prefix counts
  serve: drop "keys" strvec
  serve: provide "receive" function for session-id capability
  serve: provide "receive" function for object-format capability
  serve: add "receive" method for v2 capabilities table
  serve: return capability "value" from get_capability()
  serve: rename is_command() to parse_command()
2021-09-28 13:06:53 -07:00
Derrick Stolee
6579e788c0 advice: update message to suggest '--sparse'
The previous changes modified the behavior of 'git add', 'git rm', and
'git mv' to not adjust paths outside the sparse-checkout cone, even if
they exist in the working tree and their cache entries lack the
SKIP_WORKTREE bit. The intention is to warn users that they are doing
something potentially dangerous. The '--sparse' option was added to each
command to allow careful users the same ability they had before.

To improve the discoverability of this new functionality, add a message
to advice.updateSparsePath that mentions the existence of the option.

The previous set of changes also modified the purpose of this message to
include possibly a list of paths instead of only a list of pathspecs.
Make the warning message more clear about this new behavior.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-28 10:31:02 -07:00
Derrick Stolee
93d2c16041 mv: refuse to move sparse paths
Since cmd_mv() does not operate on cache entries and instead directly
checks the filesystem, we can only use path_in_sparse_checkout() as a
mechanism for seeing if a path is sparse or not. Be sure to skip
returning a failure if '-k' is specified.

To ensure that the advice around sparse paths is the only reason a move
failed, be sure to check this as the very last thing before inserting
into the src_for_dst list.

The tests cover a variety of cases such as whether the target is tracked
or untracked, and whether the source or destination are in or outside of
the sparse-checkout definition.

Helped-by: Matheus Tavares Bernardino <matheus.bernardino@usp.br>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-28 10:31:02 -07:00
Derrick Stolee
d7c4415e55 rm: skip sparse paths with missing SKIP_WORKTREE
If a path does not match the sparse-checkout cone but is somehow missing
the SKIP_WORKTREE bit, then 'git rm' currently succeeds in removing the
file. One reason a user might be in this situation is a merge conflict
outside of the sparse-checkout cone. Removing such a file might be
problematic for users who are not sure what they are doing.

Add a check to path_in_sparse_checkout() when 'git rm' is checking if a
path should be considered for deletion. Of course, this check is ignored
if the '--sparse' option is specified, allowing users who accept the
risks to continue with the removal.

This also removes a confusing behavior where a user asks for a directory
to be removed, but only the entries that are within the sparse-checkout
definition are removed. Now, 'git rm <dir>' will fail without '--sparse'
and will succeed in removing all contained paths with '--sparse'.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-28 10:31:02 -07:00
Derrick Stolee
f9786f9b85 rm: add --sparse option
As we did previously in 'git add', add a '--sparse' option to 'git rm'
that allows modifying paths outside of the sparse-checkout definition.
The existing checks in 'git rm' are restricted to tracked files that
have the SKIP_WORKTREE bit in the current index. Future changes will
cause 'git rm' to reject removing paths outside of the sparse-checkout
definition, even if they are untracked or do not have the SKIP_WORKTREE
bit.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-28 10:31:02 -07:00
Derrick Stolee
61d450f049 add: update --renormalize to skip sparse paths
We added checks for path_in_sparse_checkout() to portions of 'git add'
that add warnings and prevent stagins a modification, but we skipped the
--renormalize mode. Update renormalize_tracked_files() to ignore cache
entries whose path is outside of the sparse-checkout cone (unless
--sparse is provided). Add a test in t3705.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-28 10:31:02 -07:00
Derrick Stolee
63b60b3add add: update --chmod to skip sparse paths
We added checks for path_in_sparse_checkout() to portions of 'git add'
that add warnings and prevent staging a modification, but we skipped the
--chmod mode. Update chmod_pathspec() to ignore cache entries whose path
is outside of the sparse-checkout cone (unless --sparse is provided).
Add a test in t3705.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-28 10:31:02 -07:00
Derrick Stolee
0299a69694 add: implement the --sparse option
We previously modified 'git add' to refuse updating index entries
outside of the sparse-checkout cone. This is justified to prevent users
from accidentally getting into a confusing state when Git removes those
files from the working tree at some later point.

Unfortunately, this caused some workflows that were previously possible
to become impossible, especially around merge conflicts outside of the
sparse-checkout cone. These were documented in tests within t1092.

We now re-enable these workflows using a new '--sparse' option to 'git
add'. This allows users to signal "Yes, I do know what I'm doing with
these files," and accept the consequences of the files leaving the
worktree later.

We delay updating the advice message until implementing a similar option
in 'git rm' and 'git mv'.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-28 10:31:02 -07:00