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70663 commits

Author SHA1 Message Date
Junio C Hamano e43f4fd0bd The thirteenth batch
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-21 13:47:26 -07:00
Junio C Hamano 39fe402d67 Merge branch 'tb/refs-exclusion-and-packed-refs'
Enumerating refs in the packed-refs file, while excluding refs that
match certain patterns, has been optimized.

* tb/refs-exclusion-and-packed-refs:
  ls-refs.c: avoid enumerating hidden refs where possible
  upload-pack.c: avoid enumerating hidden refs where possible
  builtin/receive-pack.c: avoid enumerating hidden references
  refs.h: implement `hidden_refs_to_excludes()`
  refs.h: let `for_each_namespaced_ref()` take excluded patterns
  revision.h: store hidden refs in a `strvec`
  refs/packed-backend.c: add trace2 counters for jump list
  refs/packed-backend.c: implement jump lists to avoid excluded pattern(s)
  refs/packed-backend.c: refactor `find_reference_location()`
  refs: plumb `exclude_patterns` argument throughout
  builtin/for-each-ref.c: add `--exclude` option
  ref-filter.c: parameterize match functions over patterns
  ref-filter: add `ref_filter_clear()`
  ref-filter: clear reachable list pointers after freeing
  ref-filter.h: provide `REF_FILTER_INIT`
  refs.c: rename `ref_filter`
2023-07-21 13:47:26 -07:00
Junio C Hamano cba07a324d The twelfth batch
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-18 07:29:00 -07:00
Junio C Hamano c6a5e1a22e Merge branch 'tb/repack-cleanup'
The recent change to "git repack" made it react less nicely when a
leftover .idx file that no longer has the corresponding .pack file
in the repository, which has been corrected.

* tb/repack-cleanup:
  builtin/repack.c: avoid dir traversal in `collect_pack_filenames()`
  builtin/repack.c: only repack `.pack`s that exist
2023-07-18 07:28:53 -07:00
Junio C Hamano 6016ee0a71 Merge branch 'tb/fsck-no-progress'
"git fsck --no-progress" still spewed noise from the commit-graph
subsystem, which has been corrected.

* tb/fsck-no-progress:
  commit-graph.c: avoid duplicated progress output during `verify`
  commit-graph.c: pass progress to `verify_one_commit_graph()`
  commit-graph.c: iteratively verify commit-graph chains
  commit-graph.c: extract `verify_one_commit_graph()`
  fsck: suppress MIDX output with `--no-progress`
  fsck: suppress commit-graph output with `--no-progress`
2023-07-18 07:28:53 -07:00
Junio C Hamano d6e67222c1 Merge branch 'mh/doc-credential-helpers'
Doc update.

* mh/doc-credential-helpers:
  doc: gitcredentials: link to helper list
2023-07-18 07:28:52 -07:00
Junio C Hamano 5e238546dc The eleventh batch
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-17 11:30:43 -07:00
Junio C Hamano 13ed10efd4 Merge branch 'jc/pathspec-match-with-common-prefix'
"git ls-files '(attr:X)D/'" that triggers the common prefix
optimization codepath failed to read from "D/.gitattributes",
which has been corrected.

* jc/pathspec-match-with-common-prefix:
  dir: match "attr" pathspec magic with correct paths
  t6135: attr magic with path pattern
2023-07-17 11:30:43 -07:00
Junio C Hamano ce481ac8b3 Merge branch 'cw/compat-util-header-cleanup'
Further shuffling of declarations across header files to streamline
file dependencies.

* cw/compat-util-header-cleanup:
  git-compat-util: move alloc macros to git-compat-util.h
  treewide: remove unnecessary includes for wrapper.h
  kwset: move translation table from ctype
  sane-ctype.h: create header for sane-ctype macros
  git-compat-util: move wrapper.c funcs to its header
  git-compat-util: move strbuf.c funcs to its header
2023-07-17 11:30:42 -07:00
Junio C Hamano d5bb430ec6 Merge branch 'vd/adjust-mfow-doc-to-updated-headers'
Code snippets in a tutorial document no longer compiled after
recent header shuffling, which have been corrected.

* vd/adjust-mfow-doc-to-updated-headers:
  docs: add necessary headers to Documentation/MFOW.txt
2023-07-17 11:30:42 -07:00
Junio C Hamano 0e074fb4e5 Merge branch 'rs/ls-tree-prefix-simplify'
Code simplification.

* rs/ls-tree-prefix-simplify:
  ls-tree: simplify prefix handling
2023-07-17 11:30:42 -07:00
Junio C Hamano d383b4f24e Merge branch 'rs/userformat-find-requirements-simplify'
Code simplification.

* rs/userformat-find-requirements-simplify:
  pretty: use strchr(3) in userformat_find_requirements()
2023-07-17 11:30:41 -07:00
Junio C Hamano 55e8fad660 Merge branch 'rs/pretty-format-double-negation-fix'
Code clarification.

* rs/pretty-format-double-negation-fix:
  pretty: avoid double negative in format_commit_item()
2023-07-17 11:30:41 -07:00
Junio C Hamano 377d1ca423 Merge branch 'rs/packet-length-simplify'
Code simplification.

* rs/packet-length-simplify:
  pkt-line: add size parameter to packet_length()
2023-07-17 11:30:41 -07:00
Junio C Hamano 9187b276e9 Merge branch 'pw/diff-no-index-from-named-pipes'
"git diff --no-index" learned to read from named pipes as if they
were regular files, to allow "git diff <(process) <(substitution)"
some shells support.

* pw/diff-no-index-from-named-pipes:
  diff --no-index: support reading from named pipes
  t4054: test diff --no-index with stdin
  diff --no-index: die on error reading stdin
  diff --no-index: refuse to compare stdin to a directory
2023-07-17 11:30:41 -07:00
Junio C Hamano 830b4a04c4 The tenth batch
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-14 10:46:08 -07:00
Junio C Hamano daa2589b63 Merge branch 'jk/imap-send-unused-variable-cleanup'
"imap-send" codepaths got cleaned up to get rid of unused
parameters.

* jk/imap-send-unused-variable-cleanup:
  imap-send: drop unused fields from imap_cmd_cb
  imap-send: drop unused parameter from imap_cmd_cb callback
  imap-send: use server conf argument in setup_curl()
2023-07-14 10:46:07 -07:00
Junio C Hamano ce36dea07b Merge branch 'ma/t0091-fixup'
"git bugreport" tests did not test what it wanted to test, which
has been corrected.

* ma/t0091-fixup:
  t0091-bugreport.sh: actually verify some content of report
2023-07-14 10:46:07 -07:00
Junio C Hamano 81ebc54e81 Merge branch 'ks/ref-filter-signature'
The "git for-each-ref" family of commands learned placeholders
related to GPG signature verification.

* ks/ref-filter-signature:
  ref-filter: add new "signature" atom
  t/lib-gpg: introduce new prereq GPG2
2023-07-14 10:46:07 -07:00
Taylor Blau def390d593 builtin/repack.c: avoid dir traversal in collect_pack_filenames()
When repacking, the function `collect_pack_filenames()` is responsible
for collecting the set of existing packs in the repository, and
partitioning them into "kept" (if the pack has a ".keep" file or was
given via `--keep-pack`) and "nonkept" (otherwise) lists.

This function comes from the original C port of git-repack.sh from back
in a1bbc6c017 (repack: rewrite the shell script in C, 2013-09-15),
where it first appears as `get_non_kept_pack_filenames()`. At the time,
the implementation was a fairly direct translation from the relevant
portion of git-repack.sh, which looped over the results of

    find "$PACKDIR" -type f -name '*.pack'

either ignoring the pack as kept, or adding it to the list of existing
packs.

So the choice to directly translate this function in terms of
`readdir()` in a1bbc6c017 made sense. At the time, it was possible to
refine the C version in terms of packed_git structs, but was never done.

However, manually enumerating a repository's packs via `readdir()` is
confusing and error-prone. It leads to frustrating inconsistencies
between which packs Git considers to be part of a repository (i.e.,
could be found in the list of packs from `get_all_packs()`), and which
packs `collect_pack_filenames()` considers to meet the same criteria.

This bit us in 73320e49ad (builtin/repack.c: only collect fully-formed
packs, 2023-06-07), and again in the previous commit.

Prevent these issues from biting us in the future by implementing the
`collect_pack_filenames()` function by looping over an array of pointers
to `packed_git` structs, ensuring that we use the same criteria to
determine the set of available packs.

One gotcha here is that we have to ignore non-local packs, since the
original version of `collect_pack_filenames()` only looks at the local
pack directory to collect existing packs.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 13:07:51 -07:00
Derrick Stolee 0af067276e builtin/repack.c: only repack .packs that exist
In 73320e49ad (builtin/repack.c: only collect fully-formed packs,
2023-06-07), we switched the check for which packs to collect by
starting at the .idx files and looking for matching .pack files. This
avoids trying to repack pack-files that have not had their pack-indexes
installed yet.

However, it does cause maintenance to halt if we find the (problematic,
but not insurmountable) case of a .idx file without a corresponding
.pack file. In an environment where packfile maintenance is a critical
function, such a hard stop is costly and requires human intervention to
resolve (by deleting the .idx file).

This was not the case before. We successfully repacked through this
scenario until the recent change to scan for .idx files.

Further, if we are actually in a case where objects are missing, we
detect this at a different point during the reachability walk.

In other cases, Git prepares its list of packfiles by scanning .idx
files and then only adds it to the packfile list if the corresponding
.pack file exists. It even does so without a warning! (See
add_packed_git() in packfile.c for details.)

This case is much less likely to occur than the failures seen before
73320e49ad. Packfiles are "installed" by writing the .pack file before
the .idx and that process can be interrupted. Packfiles _should_ be
deleted by deleting the .idx first, followed by the .pack file, but
unlink_pack_path() does not do this: it deletes the .pack _first_,
allowing a window where this process could be interrupted. We leave the
consideration of changing this order as a separate concern. Knowing that
this condition is possible from interrupted Git processes and not other
tools lends some weight that Git should be more flexible around this
scenario.

Add a check to see if the .pack file exists before adding it to the list
for repacking. This will stop a number of maintenance failures seen in
production but fixed by deleting the .idx files.

This brings us closer to the case before 73320e49ad in that 'git
repack' will not fail when there is an orphaned .idx file, at least, not
due to the way we scan for packfiles. In the case that the .pack file
was erroneously deleted without copies of its objects in other installed
packfiles, then 'git repack' will fail due to the reachable object walk.

This does resolve the case where automated repacks will no longer be
halted on this case. The tests in t7700 show both these successful
scenarios and the case of failing if the .pack was truly required.

Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 13:07:50 -07:00
Taylor Blau 98456eff08 ls-refs.c: avoid enumerating hidden refs where possible
In a similar fashion as in previous commits, teach `ls-refs` to avoid
enumerating hidden references where possible.

As before, this is linux.git with one hidden reference per commit.

    $ hyperfine -L v ,.compile 'git{v} -c protocol.version=2 ls-remote .'
    Benchmark 1: git -c protocol.version=2 ls-remote .
      Time (mean ± σ):      89.8 ms ±   0.6 ms    [User: 84.3 ms, System: 5.7 ms]
      Range (min … max):    88.8 ms …  91.3 ms    32 runs

    Benchmark 2: git.compile -c protocol.version=2 ls-remote .
      Time (mean ± σ):       6.5 ms ±   0.1 ms    [User: 2.4 ms, System: 4.3 ms]
      Range (min … max):     6.2 ms …   8.3 ms    397 runs

    Summary
      'git.compile -c protocol.version=2 ls-remote .' ran
       13.85 ± 0.33 times faster than 'git -c protocol.version=2 ls-remote .'

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-10 14:48:56 -07:00
Taylor Blau 18b6b1b5c5 upload-pack.c: avoid enumerating hidden refs where possible
In a similar fashion as a previous commit, teach `upload-pack` to avoid
enumerating hidden references where possible.

Note, however, that there are certain cases where cannot avoid
enumerating even hidden references, in particular when either of:

  - `uploadpack.allowTipSHA1InWant`, or
  - `uploadpack.allowReachableSHA1InWant`

are set, corresponding to `ALLOW_TIP_SHA1` and `ALLOW_REACHABLE_SHA1`,
respectively.

When either of these bits are set, upload-pack's `is_our_ref()` function
needs to consider the `HIDDEN_REF` bit of the referent's object flags.
So we must visit all references, including the hidden ones, in order to
mark their referents with the `HIDDEN_REF` bit.

When neither `ALLOW_TIP_SHA1` nor `ALLOW_REACHABLE_SHA1` are set, the
`is_our_ref()` function considers only the `OUR_REF` bit, and not the
`HIDDEN_REF` one. `OUR_REF` is applied via `mark_our_ref()`, and only
to objects at the tips of non-hidden references, so we do not need to
visit hidden references in this case.

When neither of those bits are set, `upload-pack` can potentially avoid
enumerating a large number of references. In the same example as a
previous commit (linux.git with one hidden reference per commit,
"refs/pull/N"):

    $ printf 0000 >in
    $ hyperfine --warmup=1 \
      'git -c transfer.hideRefs=refs/pull upload-pack . <in' \
      'git.compile -c transfer.hideRefs=refs/pull -c uploadpack.allowTipSHA1InWant upload-pack . <in' \
      'git.compile -c transfer.hideRefs=refs/pull upload-pack . <in'
    Benchmark 1: git -c transfer.hideRefs=refs/pull upload-pack . <in
      Time (mean ± σ):     406.9 ms ±   1.1 ms    [User: 357.3 ms, System: 49.5 ms]
      Range (min … max):   405.7 ms … 409.2 ms    10 runs

    Benchmark 2: git.compile -c transfer.hideRefs=refs/pull -c uploadpack.allowTipSHA1InWant upload-pack . <in
      Time (mean ± σ):     406.5 ms ±   1.3 ms    [User: 356.5 ms, System: 49.9 ms]
      Range (min … max):   404.6 ms … 408.8 ms    10 runs

    Benchmark 3: git.compile -c transfer.hideRefs=refs/pull upload-pack . <in
      Time (mean ± σ):       4.7 ms ±   0.2 ms    [User: 0.7 ms, System: 3.9 ms]
      Range (min … max):     4.3 ms …   6.1 ms    472 runs

    Summary
      'git.compile -c transfer.hideRefs=refs/pull upload-pack . <in' ran
       86.62 ± 4.33 times faster than 'git.compile -c transfer.hideRefs=refs/pull -c uploadpack.allowTipSHA1InWant upload-pack . <in'
       86.70 ± 4.33 times faster than 'git -c transfer.hideRefs=refs/pull upload-pack . <in'

As above, we must visit every reference when
uploadPack.allowTipSHA1InWant is set. But when it is unset, we can visit
far fewer references.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-10 14:48:56 -07:00
Taylor Blau cc2a1f98ac builtin/receive-pack.c: avoid enumerating hidden references
Now that `refs_for_each_fullref_in()` has the ability to avoid
enumerating references matching certain pattern(s), use that to avoid
visiting hidden refs when constructing the ref advertisement via
receive-pack.

Note that since this exclusion is best-effort, we still need
`show_ref_cb()` to check whether or not each reference is hidden or not
before including it in the advertisement.

As was the case when applying this same optimization to `upload-pack`,
`receive-pack`'s reference advertisement phase can proceed much quicker
by avoiding enumerating references that will not be part of the
advertisement.

(Below, we're still using linux.git with one hidden refs/pull/N ref per
commit):

    $ hyperfine -L v ,.compile 'git{v} -c transfer.hideRefs=refs/pull receive-pack --advertise-refs .git'
    Benchmark 1: git -c transfer.hideRefs=refs/pull receive-pack --advertise-refs .git
      Time (mean ± σ):      89.1 ms ±   1.7 ms    [User: 82.0 ms, System: 7.0 ms]
      Range (min … max):    87.7 ms …  95.5 ms    31 runs

    Benchmark 2: git.compile -c transfer.hideRefs=refs/pull receive-pack --advertise-refs .git
      Time (mean ± σ):       4.5 ms ±   0.2 ms    [User: 0.5 ms, System: 3.9 ms]
      Range (min … max):     4.1 ms …   5.6 ms    508 runs

    Summary
      'git.compile -c transfer.hideRefs=refs/pull receive-pack --advertise-refs .git' ran
       20.00 ± 1.05 times faster than 'git -c transfer.hideRefs=refs/pull receive-pack --advertise-refs .git'

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-10 14:48:56 -07:00
Taylor Blau 15af64dcfd refs.h: implement hidden_refs_to_excludes()
In subsequent commits, we'll teach `receive-pack` and `upload-pack` to
use the new jump list feature in the packed-refs iterator by ignoring
references which are mentioned via its respective hideRefs lists.

However, the packed-ref jump lists cannot handle un-hiding rules (that
begin with '!'), or namespace comparisons (that begin with '^'). Add a
convenience function to the refs.h API to detect when either of these
conditions are met, and returns an appropriate value to pass as excluded
patterns.

Suggested-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-10 14:48:56 -07:00
Taylor Blau e6bf24d39a refs.h: let for_each_namespaced_ref() take excluded patterns
A future commit will want to call `for_each_namespaced_ref()` with
a list of excluded patterns.

We could introduce a variant of that function, say,
`for_each_namespaced_ref_exclude()` which takes the extra parameter, and
reimplement the original function in terms of that. But all but one
caller (in `http-backend.c`) will supply the new parameter, so add the
new parameter to `for_each_namespaced_ref()` itself instead of
introducing a new function.

For now, supply NULL for the list of excluded patterns at all callers to
avoid changing behavior, which we will do in a future change.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-10 14:48:56 -07:00
Taylor Blau c45841fff8 revision.h: store hidden refs in a strvec
In subsequent commits, it will be convenient to have a 'const char **'
of hidden refs (matching `transfer.hiderefs`, `uploadpack.hideRefs`,
etc.), instead of a `string_list`.

Convert spots throughout the tree that store the list of hidden refs
from a `string_list` to a `strvec`.

Note that in `parse_hide_refs_config()` there is an ugly const-cast used
to avoid an extra copy of each value before trimming any trailing slash
characters. This could instead be written as:

    ref = xstrdup(value);
    len = strlen(ref);
    while (len && ref[len - 1] == '/')
            ref[--len] = '\0';
    strvec_push(hide_refs, ref);
    free(ref);

but the double-copy (once when calling `xstrdup()`, and another via
`strvec_push()`) is wasteful.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-10 14:48:56 -07:00
Taylor Blau c489f47a64 refs/packed-backend.c: add trace2 counters for jump list
The previous commit added low-level tests to ensure that the packed-refs
iterator did not enumerate excluded sections of the refspace.

However, there was no guarantee that these sections weren't being
visited, only that they were being suppressed from the output. To harden
these tests, add a trace2 counter which tracks the number of regions
skipped by the packed-refs iterator, and assert on its value.

Suggested-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-10 14:48:55 -07:00
Taylor Blau 59c35fac54 refs/packed-backend.c: implement jump lists to avoid excluded pattern(s)
When iterating through the `packed-refs` file in order to answer a query
like:

    $ git for-each-ref --exclude=refs/__hidden__

it would be useful to avoid walking over all of the entries in
`refs/__hidden__/*` when possible, since we know that the ref-filter
code is going to throw them away anyways.

In certain circumstances, doing so is possible. The algorithm for doing
so is as follows:

  - For each excluded pattern, find the first record that matches it,
    and the first record that *doesn't* match it (i.e. the location
    you'd next want to consider when excluding that pattern).

  - Sort the set of excluded regions from the previous step in ascending
    order of the first location within the `packed-refs` file that
    matches.

  - Clean up the results from the previous step: discard empty regions,
    and combine adjacent regions. The set of regions which remains is
    referred to as the "jump list", and never contains any references
    which should be included in the result set.

Then when iterating through the `packed-refs` file, if `iter->pos` is
ever contained in one of the regions from the previous steps, advance
`iter->pos` past the end of that region, and continue enumeration.

Note that we only perform this optimization when none of the excluded
pattern(s) have special meta-characters in them. For a pattern like
"refs/foo[ac]", the excluded regions ("refs/fooa", "refs/fooc", and
everything underneath them) are not connected. A future implementation
that handles this case may split the character class (pretending as if
two patterns were excluded: "refs/fooa", and "refs/fooc").

There are a few other gotchas worth considering. First, note that the
jump list is sorted, so once we jump past a region, we can avoid
considering it (or any regions preceding it) again. The member
`jump_pos` is used to track the first next-possible region to jump
through.

Second, note that the jump list is best-effort, since we do not handle
loose references, and because of the meta-character issue above. The
jump list may not skip past all references which won't appear in the
results, but will never skip over a reference which does appear in the
result set.

In repositories with a large number of hidden references, the speed-up
can be significant. Tests here are done with a copy of linux.git with a
reference "refs/pull/N" pointing at every commit, as in:

    $ git rev-list HEAD | awk '{ print "create refs/pull/" NR " " $0 }' |
        git update-ref --stdin
    $ git pack-refs --all

, it is significantly faster to have `for-each-ref` jump over the
excluded references, as opposed to filtering them out after the fact:

    $ hyperfine \
      'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' \
      'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' \
      'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"'
    Benchmark 1: git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"
      Time (mean ± σ):     798.1 ms ±   3.3 ms    [User: 687.6 ms, System: 146.4 ms]
      Range (min … max):   794.5 ms … 805.5 ms    10 runs

    Benchmark 2: git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"
      Time (mean ± σ):      98.9 ms ±   1.4 ms    [User: 93.1 ms, System: 5.7 ms]
      Range (min … max):    97.0 ms … 104.0 ms    29 runs

    Benchmark 3: git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"
      Time (mean ± σ):       4.5 ms ±   0.2 ms    [User: 0.7 ms, System: 3.8 ms]
      Range (min … max):     4.1 ms …   5.8 ms    524 runs

    Summary
      'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' ran
       21.87 ± 1.05 times faster than 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"'
      176.52 ± 8.19 times faster than 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"'

(Comparing stock git and this patch isn't quite fair, since an earlier
commit in this series adds a naive implementation of the `--exclude`
option. `git.prev` is built from the previous commit and includes this
naive implementation).

Using the jump list is fairly straightforward (see the changes to
`refs/packed-backend.c::next_record()`), but constructing the list is
not. To ensure that the construction is correct, add a new suite of
tests in t1419 covering various corner cases (overlapping regions,
partially overlapping regions, adjacent regions, etc.).

Co-authored-by: Jeff King <peff@peff.net>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-10 14:48:55 -07:00
Taylor Blau d22d941ac0 refs/packed-backend.c: refactor find_reference_location()
The function `find_reference_location()` is used to perform a
binary search-like function over the contents of a repository's
`$GIT_DIR/packed-refs` file.

The search it implements is unlike a standard binary search in that the
records it searches over are not of a fixed width, so the comparison
must locate the end of a record before comparing it.

Extract the core routine of `find_reference_location()` in order to
implement a function in the following patch which will find the first
location in the `packed-refs` file that *doesn't* match the given
pattern.

The behavior of `find_reference_location()` is unchanged.

Co-authored-by: Jeff King <peff@peff.net>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-10 14:48:55 -07:00
Taylor Blau b269ac53c0 refs: plumb exclude_patterns argument throughout
The subsequent patch will want to access an optional `excluded_patterns`
array within `refs/packed-backend.c` that will cull out certain
references matching any of the given patterns on a best-effort basis.

To do so, the refs subsystem needs to be updated to pass this value
across a number of different locations.

Prepare for a future patch by introducing this plumbing now, passing
NULLs at top-level APIs in order to make that patch less noisy and more
easily readable.

Signed-off-by: Taylor Blau <me@ttaylorr.co>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-10 14:48:55 -07:00
Taylor Blau 8255dd8a3d builtin/for-each-ref.c: add --exclude option
When using `for-each-ref`, it is sometimes convenient for the caller to
be able to exclude certain parts of the references.

For example, if there are many `refs/__hidden__/*` references, the
caller may want to emit all references *except* the hidden ones.
Currently, the only way to do this is to post-process the output, like:

    $ git for-each-ref --format='%(refname)' | grep -v '^refs/hidden/'

Which is do-able, but requires processing a potentially large quantity
of references.

Teach `git for-each-ref` a new `--exclude=<pattern>` option, which
excludes references from the results if they match one or more excluded
patterns.

This patch provides a naive implementation where the `ref_filter` still
sees all references (including ones that it will discard) and is left to
check whether each reference matches any excluded pattern(s) before
emitting them.

By culling out references we know the caller doesn't care about, we can
avoid allocating memory for their storage, as well as spending time
sorting the output (among other things). Even the naive implementation
provides a significant speed-up on a modified copy of linux.git (that
has a hidden ref pointing at each commit):

    $ hyperfine \
      'git.compile for-each-ref --format="%(objectname) %(refname)" | grep -vE "[0-9a-f]{40} refs/pull/"' \
      'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude refs/pull/'
    Benchmark 1: git.compile for-each-ref --format="%(objectname) %(refname)" | grep -vE "[0-9a-f]{40} refs/pull/"
      Time (mean ± σ):     820.1 ms ±   2.0 ms    [User: 703.7 ms, System: 152.0 ms]
      Range (min … max):   817.7 ms … 823.3 ms    10 runs

    Benchmark 2: git.compile for-each-ref --format="%(objectname) %(refname)" --exclude refs/pull/
      Time (mean ± σ):     106.6 ms ±   1.1 ms    [User: 99.4 ms, System: 7.1 ms]
      Range (min … max):   104.7 ms … 109.1 ms    27 runs

    Summary
      'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude refs/pull/' ran
        7.69 ± 0.08 times faster than 'git.compile for-each-ref --format="%(objectname) %(refname)" | grep -vE "[0-9a-f]{40} refs/pull/"'

Subsequent patches will improve on this by avoiding visiting excluded
sections of the `packed-refs` file in certain cases.

Co-authored-by: Jeff King <peff@peff.net>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-10 14:48:55 -07:00
Jeff King 284c55deb5 ref-filter.c: parameterize match functions over patterns
`match_pattern()` and `match_name_as_path()` both take a `struct
ref_filter *`, and then store a stack variable `patterns` pointing at
`filter->patterns`.

The subsequent patch will add a new array of patterns to match over (the
excluded patterns, via a new `git for-each-ref --exclude` option),
treating the return value of these functions differently depending on
which patterns are being used to match.

Tweak `match_pattern()` and `match_name_as_path()` to take an array of
patterns to prepare for passing either in.

Once we start passing either in, `match_pattern()` will have little to
do with a particular `struct ref_filter *` instance. To clarify this,
drop it from the argument list, and replace it with the only bit of the
`ref_filter` that we care about (`filter->ignore_case`).

Co-authored-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-10 14:48:55 -07:00
Jeff King b571fb9800 ref-filter: add ref_filter_clear()
We did not bother to clean up at all in `git branch` or `git tag`, and
`git for-each-ref` only cleans up a couple of members.

Add and call `ref_filter_clear()` when cleaning up a `struct
ref_filter`. Running this patch (without any test changes) indicates a
couple of now leak-free tests. This was found by running:

    $ make SANITIZE=leak
    $ make -C t GIT_TEST_PASSING_SANITIZE_LEAK=check GIT_TEST_OPTS=--immediate

(Note that the `reachable_from` and `unreachable_from` lists should be
cleaned as they are used. So this is just covering any case where we
might bail before running the reachability check.)

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-10 14:48:55 -07:00
Jeff King 311bfe18ce ref-filter: clear reachable list pointers after freeing
In `reach_filter()`, we pop all commits from the reachable lists,
leaving them empty. But because we're operating on a list pointer that
was passed by value, the original `filter.reachable_from` and
`filter.unreachable_from` pointers are left dangling.

As is the case with the previous commit, nobody touches either of these
fields after calling `reach_filter()`, so leaving them dangling is OK.
But this future proofs against dangerous situations.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-10 14:48:55 -07:00
Jeff King b9f7daa6ef ref-filter.h: provide REF_FILTER_INIT
Provide a sane initialization value for `struct ref_filter`, which in a
subsequent patch will be used to initialize a new field.

In the meantime, ensure that the `ref_filter` struct used in the
test-helper's `cmd__reach()` is zero-initialized. The lack of
initialization is OK, since `commit_contains()` only looks at the single
`with_commit_tag_algo` field that *is* initialized directly above.

So this does not fix a bug, but rather prevents one from biting us in
the future.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-10 14:48:55 -07:00
Jeff King bf1377a12b refs.c: rename ref_filter
The refs machinery has its own implementation of a `ref_filter` (used by
`for-each-ref`), which is distinct from the `ref-filter.h` API (also
used by `for-each-ref`, among other things).

Rename the one within refs.c to more clearly indicate its purpose.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-10 14:48:55 -07:00
M Hickford 4c9cb51fe7 doc: gitcredentials: link to helper list
Link to community list of credential helpers. This is useful information
for users.

Describe how OAuth credential helpers work. OAuth is a user-friendly
alternative to personal access tokens and SSH keys. Reduced setup cost
makes it easier for users to contribute to projects across multiple
forges.

Signed-off-by: M Hickford <mirth.hickford@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-10 10:35:55 -07:00
Taylor Blau 9281cd07f0 commit-graph.c: avoid duplicated progress output during verify
When `git commit-graph verify` was taught how to verify commit-graph
chains in 3da4b609bb (commit-graph: verify chains with --shallow mode,
2019-06-18), it produced one line of progress per layer of the
commit-graph chain.

    $ git.compile commit-graph verify
    Verifying commits in commit graph: 100% (4356/4356), done.
    Verifying commits in commit graph: 100% (131912/131912), done.

This could be somewhat confusing to users, who may wonder why there are
multiple occurrences of "Verifying commits in commit graph".

There are likely good arguments on whether or not there should be
one line of progress output per commit-graph layer. On the one hand, the
existing output shows us verifying each individual layer of the chain.
But on the other hand, the fact that a commit-graph may be stored among
multiple layers is an implementation detail that the caller need not be
aware of.

Clarify this by showing a single progress meter regardless of the number
of layers in the commit-graph chain. After this patch, the output
reflects the logical contents of a commit-graph chain, instead of
showing one line of output per commit-graph layer:

    $ git.compile commit-graph verify
    Verifying commits in commit graph: 100% (136268/136268), done.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Acked-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-10 10:02:45 -07:00
Taylor Blau 7248857b6e commit-graph.c: pass progress to verify_one_commit_graph()
This is the final step to prepare for consolidating the output of `git
commit-graph verify`. Instead of having each call to
`verify_one_commit_graph()` initialize its own progress struct, have the
caller pass one in instead.

This patch does not alter the output of `git commit-graph verify`, but
the next commit will consolidate the output.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Acked-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-10 10:02:43 -07:00
Taylor Blau f5facaa465 commit-graph.c: iteratively verify commit-graph chains
Now that we have a function which can verify a single layer of a
commit-graph chain, implement `verify_commit_graph()` in terms of
iterating over commit-graphs along their `->base_graph` pointers.

This further prepares us to consolidate the progress output of `git
commit-graph verify`.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Acked-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-10 10:02:42 -07:00
Taylor Blau eb319d6771 commit-graph.c: extract verify_one_commit_graph()
When the `verify_commit_graph()` function was extended to support
commit-graph chains via 3da4b609bb (commit-graph: verify chains with
--shallow mode, 2019-06-18), it did so by recursively calling itself on
each layer of the commit-graph chain.

In practice this poses no issues, since commit-graph chains do not loop,
and there are few enough of them that adding additional frames to the
stack is not a problem.

A future commit will consolidate the progress output from `git
commit-graph verify` when verifying chained commit-graphs to print a
single line instead of one progress meter per commit-graph layer.
Prepare for this by extracting a routine to verify a single layer of a
commit-graph.

Note that `verify_commit_graph()` is still recursive after this patch,
but this will change in the subsequent patch.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Acked-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-10 10:02:41 -07:00
Taylor Blau 39bdd30377 fsck: suppress MIDX output with --no-progress
In a similar spirit as the previous commit, address a bug where `git
fsck` produces output when calling `git multi-pack-index verify` even
when invoked with `--no-progress`.

    $ git.compile fsck --connectivity-only --no-progress --no-dangling
    Verifying OID order in multi-pack-index: 100% (605677/605677), done.
    Sorting objects by packfile: 100% (605678/605678), done.
    Verifying object offsets: 100% (605678/605678), done.

The three lines produced by `git fsck` come from `git multi-pack-index
verify`, but should be squelched due to `--no-progress`.

The MIDX machinery learned to generate these progress messages as early
as 430efb8a74 (midx: add progress indicators in multi-pack-index
verify, 2019-03-21), but did not respect `--progress` or `--no-progress`
until ad60096d1c (midx: honor the MIDX_PROGRESS flag in
verify_midx_file, 2019-10-21).

But the `git multi-pack-index verify` step was added to fsck in
66ec0390e7 (fsck: verify multi-pack-index, 2018-09-13), pre-dating any
of the above patches.

Pass `--[no-]progress` as appropriate to ensure that we don't produce
output when told not to.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Acked-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-10 10:02:40 -07:00
Taylor Blau eda206f611 fsck: suppress commit-graph output with --no-progress
Since e0fd51e1d7 (fsck: verify commit-graph, 2018-06-27), `fsck` runs
`git commit-graph verify` to check the integrity of any commit-graph(s).

Originally, the `git commit-graph verify` step would always print to
stdout/stderr, regardless of whether or not `fsck` was invoked with
`--[no-]progress` or not. But in 7371612255 (commit-graph: add
--[no-]progress to write and verify, 2019-08-26), the commit-graph
machinery learned the `--[no-]progress` option, though `fsck` was not
updated to pass this new flag (or not).

This led to seeing output from running `git fsck`, even with
`--no-progress` on repositories that have a commit-graph:

    $ git.compile fsck --connectivity-only --no-progress --no-dangling
    Verifying commits in commit graph: 100% (4356/4356), done.
    Verifying commits in commit graph: 100% (131912/131912), done.

Ensure that `fsck` passes `--[no-]progress` as appropriate when calling
`git commit-graph verify`.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Acked-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-10 10:02:37 -07:00
Junio C Hamano f4a8fde057 dir: match "attr" pathspec magic with correct paths
The match_pathspec_item() function takes "prefix" value, allowing a
caller to chop off the common leading prefix of pathspec pattern
strings from the path and only use the remainder of the path to
match the pathspec patterns (after chopping the same leading prefix
of them, of course).

This "common leading prefix" optimization has two main features:

 * discard the entries in the in-core index that are outside of the
   common leading prefix; if you are doing "ls-files one/a one/b",
   we know all matches must be from "one/", so first the code
   discards all entries outside the "one/" directory from the
   in-core index.  This allows us to work on a smaller dataset.

 * allow skipping the comparison of the leading bytes when matching
   pathspec with path.  When "ls-files" finds the path "one/a/1" in
   the in-core index given "one/a" and "one/b" as the pathspec,
   knowing that common leading prefix "one/" was found lets the
   pathspec matchinery not to bother comparing "one/" part, and
   allows it to feed "a/1" down, as long as the pathspec element
   "one/a" gets corresponding adjustment to "a".

When the "attr" pathspec magic is in effect, however, the current
code breaks down.

The attributes, other than the ones that are built-in and the ones
that come from the $GIT_DIR/info/attributes file and the top-level
.gitattributes file, are lazily read from the filesystem on-demand,
as we encounter each path and ask if it matches the pathspec.  For
example, if you say "git ls-files "(attr:label)sub/" in a repository
with a file "sub/file" that is given the 'label' attribute in
"sub/.gitattributes":

 * The common prefix optimization finds that "sub/" is the common
   prefix and prunes the in-core index so that it has only entries
   inside that directory.  This is desirable.

 * The code then walks the in-core index, finds "sub/file", and
   eventually asks do_match_pathspec() if it matches the given
   pathspec.

 * do_match_pathspec() calls match_pathspec_item() _after_ stripping
   the common prefix "sub/" from the path, giving it "file", plus
   the length of the common prefix (4-bytes), so that the pathspec
   element "(attr:label)sub/" can be treated as if it were "(attr:label)".

The last one is what breaks the match in the current code, as the
pathspec subsystem ends up asking the attribute subsystem to find
the attribute attached to the path "file".  We need to ask about the
attributes on "sub/file" when calling match_pathspec_attrs(); this
can be done by looking at "prefix" bytes before the beginning of
"name", which is the same trick already used by another piece of the
code in the same match_pathspec_item() function.

Unfortunately this was not discovered so far because the code works
with slightly different arguments, e.g.

 $ git ls-files "(attr:label)sub"
 $ git ls-files "(attr:label)sub/" "no/such/dir/"

would have reported "sub/file" as a path with the 'label' attribute
just fine, because neither would trigger the common prefix
optimization.

Reported-by: Matthew Hughes <mhughes@uw.co.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-08 14:36:31 -07:00
Junio C Hamano aa9166bcc0 The ninth batch
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-08 11:23:08 -07:00
Junio C Hamano b00ec259e7 Merge branch 'jk/fsck-indices-in-worktrees'
Code clarification.

* jk/fsck-indices-in-worktrees:
  fsck: avoid misleading variable name
2023-07-08 11:23:08 -07:00
Junio C Hamano 7f5ad0ca8d Merge branch 'js/empty-index-fixes'
A few places failed to differenciate the case where the index is
truly empty (nothing added) and we haven't yet read from the
on-disk index file, which have been corrected.

* js/empty-index-fixes:
  commit -a -m: allow the top-level tree to become empty again
  split-index: accept that a base index can be empty
  do_read_index(): always mark index as initialized unless erroring out
2023-07-08 11:23:07 -07:00
Junio C Hamano d52a45cf56 Merge branch 'ks/t4205-test-describe-with-abbrev-fix'
Test update.

* ks/t4205-test-describe-with-abbrev-fix:
  t4205: correctly test %(describe:abbrev=...)
2023-07-08 11:23:07 -07:00
René Scharfe bd19ee9c45 pretty: use strchr(3) in userformat_find_requirements()
The strbuf_expand_step() loop in userformat_find_requirements() iterates
through the percent signs in the string "fmt", but we're not interested
in its effect on the strbuf "dummy".  Use strchr(3) instead and get rid
of the strbuf that we no longer need.

Suggested-by: Jeff King <peff@peff.net>
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-07 15:32:57 -07:00