Commit Graph

896 Commits

Author SHA1 Message Date
SZEDER Gábor
fa83cc834d parse-options: add support for parsing subcommands
Several Git commands have subcommands to implement mutually exclusive
"operation modes", and they usually parse their subcommand argument
with a bunch of if-else if statements.

Teach parse-options to handle subcommands as well, which will result
in shorter and simpler code with consistent error handling and error
messages on unknown or missing subcommand, and it will also make
possible for our Bash completion script to handle subcommands
programmatically.

The approach is guided by the following observations:

  - Most subcommands [1] are implemented in dedicated functions, and
    most of those functions [2] either have a signature matching the
    'int cmd_foo(int argc, const char **argc, const char *prefix)'
    signature of builtin commands or can be trivially converted to
    that signature, because they miss only that last prefix parameter
    or have no parameters at all.

  - Subcommand arguments only have long form, and they have no double
    dash prefix, no negated form, and no description, and they don't
    take any arguments, and can't be abbreviated.

  - There must be exactly one subcommand among the arguments, or zero
    if the command has a default operation mode.

  - All arguments following the subcommand are considered to be
    arguments of the subcommand, and, conversely, arguments meant for
    the subcommand may not preceed the subcommand.

So in the end subcommand declaration and parsing would look something
like this:

    parse_opt_subcommand_fn *fn = NULL;
    struct option builtin_commit_graph_options[] = {
        OPT_STRING(0, "object-dir", &opts.obj_dir, N_("dir"),
                   N_("the object directory to store the graph")),
        OPT_SUBCOMMAND("verify", &fn, graph_verify),
        OPT_SUBCOMMAND("write", &fn, graph_write),
        OPT_END(),
    };
    argc = parse_options(argc, argv, prefix, options,
                         builtin_commit_graph_usage, 0);
    return fn(argc, argv, prefix);

Here each OPT_SUBCOMMAND specifies the name of the subcommand and the
function implementing it, and the address of the same 'fn' subcommand
function pointer.  parse_options() then processes the arguments until
it finds the first argument matching one of the subcommands, sets 'fn'
to the function associated with that subcommand, and returns, leaving
the rest of the arguments unprocessed.  If none of the listed
subcommands is found among the arguments, parse_options() will show
usage and abort.

If a command has a default operation mode, 'fn' should be initialized
to the function implementing that mode, and parse_options() should be
invoked with the PARSE_OPT_SUBCOMMAND_OPTIONAL flag.  In this case
parse_options() won't error out when not finding any subcommands, but
will return leaving 'fn' unchanged.  Note that if that default
operation mode has any --options, then the PARSE_OPT_KEEP_UNKNOWN_OPT
flag is necessary as well (otherwise parse_options() would error out
upon seeing the unknown option meant to the default operation mode).

Some thoughts about the implementation:

  - The same pointer to 'fn' must be specified as 'value' for each
    OPT_SUBCOMMAND, because there can be only one set of mutually
    exclusive subcommands; parse_options() will BUG() otherwise.

    There are other ways to tell parse_options() where to put the
    function associated with the subcommand given on the command line,
    but I didn't like them:

      - Change parse_options()'s signature by adding a pointer to
        subcommand function to be set to the function associated with
        the given subcommand, affecting all callsites, even those that
        don't have subcommands.

      - Introduce a specific parse_options_and_subcommand() variant
        with that extra funcion parameter.

  - I decided against automatically calling the subcommand function
    from within parse_options(), because:

      - There are commands that have to perform additional actions
        after option parsing but before calling the function
        implementing the specified subcommand.

      - The return code of the subcommand is usually the return code
        of the git command, but preserving the return code of the
        automatically called subcommand function would have made the
        API awkward.

  - Also add a OPT_SUBCOMMAND_F() variant to allow specifying an
    option flag: we have two subcommands that are purposefully
    excluded from completion ('git remote rm' and 'git stash save'),
    so they'll have to be specified with the PARSE_OPT_NOCOMPLETE
    flag.

  - Some of the 'parse_opt_flags' don't make sense with subcommands,
    and using them is probably just an oversight or misunderstanding.
    Therefore parse_options() will BUG() when invoked with any of the
    following flags while the options array contains at least one
    OPT_SUBCOMMAND:

      - PARSE_OPT_KEEP_DASHDASH: parse_options() stops parsing
        arguments when encountering a "--" argument, so it doesn't
        make sense to expect and keep one before a subcommand, because
        it would prevent the parsing of the subcommand.

        However, this flag is allowed in combination with the
        PARSE_OPT_SUBCOMMAND_OPTIONAL flag, because the double dash
        might be meaningful for the command's default operation mode,
        e.g. to disambiguate refs and pathspecs.

      - PARSE_OPT_STOP_AT_NON_OPTION: As its name suggests, this flag
        tells parse_options() to stop as soon as it encouners a
        non-option argument, but subcommands are by definition not
        options...  so how could they be parsed, then?!

      - PARSE_OPT_KEEP_UNKNOWN: This flag can be used to collect any
        unknown --options and then pass them to a different command or
        subsystem.  Surely if a command has subcommands, then this
        functionality should rather be delegated to one of those
        subcommands, and not performed by the command itself.

        However, this flag is allowed in combination with the
        PARSE_OPT_SUBCOMMAND_OPTIONAL flag, making possible to pass
        --options to the default operation mode.

  - If the command with subcommands has a default operation mode, then
    all arguments to the command must preceed the arguments of the
    subcommand.

    AFAICT we don't have any commands where this makes a difference,
    because in those commands either only the command accepts any
    arguments ('notes' and 'remote'), or only the default subcommand
    ('reflog' and 'stash'), but never both.

  - The 'argv' array passed to subcommand functions currently starts
    with the name of the subcommand.  Keep this behavior.  AFAICT no
    subcommand functions depend on the actual content of 'argv[0]',
    but the parse_options() call handling their options expects that
    the options start at argv[1].

  - To support handling subcommands programmatically in our Bash
    completion script, 'git cmd --git-completion-helper' will now list
    both subcommands and regular --options, if any.  This means that
    the completion script will have to separate subcommands (i.e.
    words without a double dash prefix) from --options on its own, but
    that's rather easy to do, and it's not much work either, because
    the number of subcommands a command might have is rather low, and
    those commands accept only a single --option or none at all.  An
    alternative would be to introduce a separate option that lists
    only subcommands, but then the completion script would need not
    one but two git invocations and command substitutions for commands
    with subcommands.

    Note that this change doesn't affect the behavior of our Bash
    completion script, because when completing the --option of a
    command with subcommands, e.g. for 'git notes --<TAB>', then all
    subcommands will be filtered out anyway, as none of them will
    match the word to be completed starting with that double dash
    prefix.

[1] Except 'git rerere', because many of its subcommands are
    implemented in the bodies of the if-else if statements parsing the
    command's subcommand argument.

[2] Except 'credential', 'credential-store' and 'fsmonitor--daemon',
    because some of the functions implementing their subcommands take
    special parameters.

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-19 11:13:14 -07:00
SZEDER Gábor
99d86d60e5 parse-options: PARSE_OPT_KEEP_UNKNOWN only applies to --options
The description of 'PARSE_OPT_KEEP_UNKNOWN' starts with "Keep unknown
arguments instead of erroring out".  This is a bit misleading, as this
flag only applies to unknown --options, while non-option arguments are
kept even without this flag.

Update the description to clarify this, and rename the flag to
PARSE_OPTIONS_KEEP_UNKNOWN_OPT to make this obvious just by looking at
the flag name.

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-19 11:13:14 -07:00
SZEDER Gábor
80882bc5e7 api-parse-options.txt: fix description of OPT_CMDMODE
The description of the 'OPT_CMDMODE' macro states that "enum_val is
set to int_var when ...", but it's the other way around, 'int_var' is
set to 'enum_val'.  Fix this.

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-19 11:13:14 -07:00
Junio C Hamano
5dbbdaac79 Merge branch 'ac/bitmap-format-doc'
Adjust technical/bitmap-format to be formatted by AsciiDoc, and
add some missing information to the documentation.

* ac/bitmap-format-doc:
  bitmap-format.txt: add information for trailing checksum
  bitmap-format.txt: fix some formatting issues
  bitmap-format.txt: feed the file to asciidoc to generate html
2022-07-11 15:38:50 -07:00
Abhradeep Chakraborty
ac7667bd44 bitmap-format.txt: add information for trailing checksum
Bitmap file has a trailing checksum at the end of the file. However
there is no information in the bitmap-format documentation about it.

Add a trailer section to include the trailing checksum info in the
`Documentation/technical/bitmap-format.txt` file.

Signed-off-by: Abhradeep Chakraborty <chakrabortyabhradeep79@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-06-16 11:48:50 -07:00
Abhradeep Chakraborty
caea900272 bitmap-format.txt: fix some formatting issues
The asciidoc generated html for `Documentation/technical/bitmap-
format.txt` is broken. This is mainly because `-` is used for nested
lists (which is not allowed in asciidoc) instead of `*`.

Fix these and also reformat it for better readability of the html page.

Signed-off-by: Abhradeep Chakraborty <chakrabortyabhradeep79@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-06-16 11:48:50 -07:00
Junio C Hamano
4da14b574f Merge branch 'ab/bug-if-bug'
A new bug() and BUG_if_bug() API is introduced to make it easier to
uniformly log "detect multiple bugs and abort in the end" pattern.

* ab/bug-if-bug:
  cache-tree.c: use bug() and BUG_if_bug()
  receive-pack: use bug() and BUG_if_bug()
  parse-options.c: use optbug() instead of BUG() "opts" check
  parse-options.c: use new bug() API for optbug()
  usage.c: add a non-fatal bug() function to go with BUG()
  common-main.c: move non-trace2 exit() behavior out of trace2.c
2022-06-10 15:04:15 -07:00
Junio C Hamano
a50036da1a Merge branch 'tb/cruft-packs'
A mechanism to pack unreachable objects into a "cruft pack",
instead of ejecting them into loose form to be reclaimed later, has
been introduced.

* tb/cruft-packs:
  sha1-file.c: don't freshen cruft packs
  builtin/gc.c: conditionally avoid pruning objects via loose
  builtin/repack.c: add cruft packs to MIDX during geometric repack
  builtin/repack.c: use named flags for existing_packs
  builtin/repack.c: allow configuring cruft pack generation
  builtin/repack.c: support generating a cruft pack
  builtin/pack-objects.c: --cruft with expiration
  reachable: report precise timestamps from objects in cruft packs
  reachable: add options to add_unseen_recent_objects_to_traversal
  builtin/pack-objects.c: --cruft without expiration
  builtin/pack-objects.c: return from create_object_entry()
  t/helper: add 'pack-mtimes' test-tool
  pack-mtimes: support writing pack .mtimes files
  chunk-format.h: extract oid_version()
  pack-write: pass 'struct packing_data' to 'stage_tmp_packfiles'
  pack-mtimes: support reading .mtimes files
  Documentation/technical: add cruft-packs.txt
2022-06-03 14:30:37 -07:00
Ævar Arnfjörð Bjarmason
0cc05b044f usage.c: add a non-fatal bug() function to go with BUG()
Add a bug() function to use in cases where we'd like to indicate a
runtime BUG(), but would like to defer the BUG() call because we're
possibly accumulating more bug() callers to exhaustively indicate what
went wrong.

We already have this sort of facility in various parts of the
codebase, just in the form of ad-hoc re-inventions of the
functionality that this new API provides. E.g. this will be used to
replace optbug() in parse-options.c, and the 'error("BUG:[...]' we do
in a loop in builtin/receive-pack.c.

Unlike the code this replaces we'll log to trace2 with this new bug()
function (as with other usage.c functions, including BUG()), we'll
also be able to avoid calls to xstrfmt() in some cases, as the bug()
function itself accepts variadic sprintf()-like arguments.

Any caller to bug() can follow up such calls with BUG_if_bug(),
which will BUG() out (i.e. abort()) if there were any preceding calls
to bug(), callers can also decide not to call BUG_if_bug() and leave
the resulting BUG() invocation until exit() time. There are currently
no bug() API users that don't call BUG_if_bug() themselves after a
for-loop, but allowing for not calling BUG_if_bug() keeps the API
flexible. As the tests and documentation here show we'll catch missing
BUG_if_bug() invocations in our exit() wrapper.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-06-02 12:51:35 -07:00
Taylor Blau
f9825d1cf7 builtin/repack.c: support generating a cruft pack
Expose a way to split the contents of a repository into a main and cruft
pack when doing an all-into-one repack with `git repack --cruft -d`, and
a complementary configuration variable.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-26 15:48:26 -07:00
Taylor Blau
94cd775a6c pack-mtimes: support reading .mtimes files
To store the individual mtimes of objects in a cruft pack, introduce a
new `.mtimes` format that can optionally accompany a single pack in the
repository.

The format is defined in Documentation/technical/pack-format.txt, and
stores a 4-byte network order timestamp for each object in name (index)
order.

This patch prepares for cruft packs by defining the `.mtimes` format,
and introducing a basic API that callers can use to read out individual
mtimes.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-26 15:48:26 -07:00
Taylor Blau
3d89a8c118 Documentation/technical: add cruft-packs.txt
Create a technical document to explain cruft packs. It contains a brief
overview of the problem, some background, details on the implementation,
and a couple of alternative approaches not considered here.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-20 22:31:21 -07:00
Johannes Schindelin
a6c80c313c trace2 docs: add missing full stop
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-04 10:31:05 -07:00
Johannes Schindelin
236d1177ba trace2 docs: clarify what varargs is all about
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-04 10:31:05 -07:00
Johannes Schindelin
c4667b17fb trace2 docs: fix a JSON formatted example
The example was not in valid JSON format due to a duplicate key "sid".

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-04 10:31:04 -07:00
Johannes Schindelin
1c538b951f trace2 docs: surround more terms in backticks
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-04 10:31:04 -07:00
Johannes Schindelin
c191b9188b trace2 docs: "printf" is not an English word
We append an ellipsis and enclose it in backticks to indicate that it is
a function elsewhere, let's also use that here.

While at it, ensure the same for `waitpid()`.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-04 10:31:04 -07:00
Johannes Schindelin
3188d3c0b9 trace2 docs: a couple of grammar fixes
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-04 10:31:04 -07:00
Junio C Hamano
0f5e885173 Merge branch 'rc/fetch-refetch'
"git fetch --refetch" learned to fetch everything without telling
the other side what we already have, which is useful when you
cannot trust what you have in the local object store.

* rc/fetch-refetch:
  docs: mention --refetch fetch option
  fetch: after refetch, encourage auto gc repacking
  t5615-partial-clone: add test for fetch --refetch
  fetch: add --refetch option
  builtin/fetch-pack: add --refetch option
  fetch-pack: add refetch
  fetch-negotiator: add specific noop initializer
2022-04-04 10:56:23 -07:00
Robert Coup
4963d3e41f docs: mention --refetch fetch option
Document it for partial clones as a means to apply a new filter, and
reference it from the remote.<name>.partialclonefilter config parameter.

Signed-off-by: Robert Coup <robert@coup.net.nz>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-28 10:25:53 -07:00
Junio C Hamano
7391ecd338 Merge branch 'ds/partial-bundles'
Bundle file format gets extended to allow a partial bundle,
filtered by similar criteria you would give when making a
partial/lazy clone.

* ds/partial-bundles:
  clone: fail gracefully when cloning filtered bundle
  bundle: unbundle promisor packs
  bundle: create filtered bundles
  rev-list: move --filter parsing into revision.c
  bundle: parse filter capability
  list-objects: handle NULL function pointers
  MyFirstObjectWalk: update recommended usage
  list-objects: consolidate traverse_commit_list[_filtered]
  pack-bitmap: drop filter in prepare_bitmap_walk()
  pack-objects: use rev.filter when possible
  revision: put object filter into struct rev_info
  list-objects-filter-options: create copy helper
  index-pack: document and test the --promisor option
2022-03-21 15:14:24 -07:00
Junio C Hamano
a54cc523ad Merge branch 'ds/commit-graph-gen-v2-fixes'
Fixes to the way generation number v2 in the commit-graph files are
(not) handled.

* ds/commit-graph-gen-v2-fixes:
  commit-graph: declare bankruptcy on GDAT chunks
  commit-graph: fix generation number v2 overflow values
  commit-graph: start parsing generation v2 (again)
  commit-graph: fix ordering bug in generation numbers
  t5318: extract helpers to lib-commit-graph.sh
  test-read-graph: include extra post-parse info
2022-03-16 17:53:09 -07:00
Derrick Stolee
105c6f14ad bundle: parse filter capability
The v3 bundle format has capabilities, allowing newer versions of Git to
create bundles with newer features. Older versions that do not
understand these new capabilities will fail with a helpful warning.

Create a new capability allowing Git to understand that the contained
pack-file is filtered according to some object filter. Typically, this
filter will be "blob:none" for a blobless partial clone.

This change teaches Git to parse this capability, place its value in the
bundle header, and demonstrate this understanding by adding a message to
'git bundle verify'.

Since we will use gently_parse_list_objects_filter() outside of
list-objects-filter-options.c, make it an external method and move its
API documentation to before its declaration.

Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-09 10:25:27 -08:00
Derrick Stolee
6dbf4b8172 commit-graph: declare bankruptcy on GDAT chunks
The Generation Data (GDAT) and Generation Data Overflow (GDOV) chunks
store corrected commit date offsets, used for generation number v2.
Recent changes have demonstrated that previous versions of Git were
incorrectly parsing data from these chunks, but might have also been
writing them incorrectly.

I asserted [1] that the previous fixes were sufficient because the known
reasons for incorrectly writing generation number v2 data relied on
parsing the information incorrectly out of a commit-graph file, but the
previous versions of Git were not reading the generation number v2 data.

However, Patrick demonstrated [2] a case where in split commit-graphs
across an alternate boundary (and possibly some other special
conditions) it was possible to have a commit-graph that was generated by
a previous version of Git have incorrect generation number v2 data which
results in errors like the following:

  commit-graph generation for commit <oid> is 1623273624 < 1623273710

[1] https://lore.kernel.org/git/f50e74f0-9ffa-f4f2-4663-269801495ed3@github.com/
[2] https://lore.kernel.org/git/Yh93vOkt2DkrGPh2@ncase/

Clearly, there is something else going on. The situation is not
completely understood, but the errors do not reproduce if the
commit-graphs are all generated by a Git version including these recent
fixes.

If we cannot trust the existing data in the GDAT and GDOV chunks, then
we can alter the format to change the chunk IDs for these chunks. This
causes the new version of Git to silently ignore the older chunks (and
disabling generation number v2 in the process) while writing new
commit-graph files with correct data in the GDA2 and GDO2 chunks.

Update commit-graph-format.txt including a historical note about these
deprecated chunks.

Reported-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-07 09:17:03 -08:00
Han-Wen Nienhuys
fa48de62ac Documentation: object_id_len goes up to 31
The value is stored in a 5-bit field, so we can't support more without
a format version upgrade.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-23 13:36:26 -08:00
Taylor Blau
95e8383bac midx.c: make changing the preferred pack safe
The previous patch demonstrates a bug where a MIDX's auxiliary object
order can become out of sync with a MIDX bitmap.

This is because of two confounding factors:

  - First, the object order is stored in a file which is named according
    to the multi-pack index's checksum, and the MIDX does not store the
    object order. This means that the object order can change without
    altering the checksum.

  - But the .rev file is moved into place with finalize_object_file(),
    which link(2)'s the file into place instead of renaming it. For us,
    that means that a modified .rev file will not be moved into place if
    MIDX's checksum was unchanged.

This fix is to force the MIDX's checksum to change when the preferred
pack changes but the set of packs contained in the MIDX does not. In
other words, when the object order changes, the MIDX's checksum needs to
change with it (regardless of whether the MIDX is tracking the same or
different packs).

This prevents a race whereby changing the object order (but not the
packs themselves) enables a reader to see the new .rev file with the old
MIDX, or similarly seeing the new bitmap with the old object order.

But why can't we just stop hardlinking the .rev into place instead
adding additional data to the MIDX? Suppose that's what we did. Then
when we go to generate the new bitmap, we'll load the old MIDX bitmap,
along with the MIDX that it references. That's fine, since the new MIDX
isn't moved into place until after the new bitmap is generated. But the
new object order *has* been moved into place. So we'll read the old
bitmaps in the new order when generating the new bitmap file, meaning
that without this secondary change, bitmap generation itself would
become a victim of the race described here.

This can all be prevented by forcing the MIDX's checksum to change when
the object order does. By embedding the entire object order into the
MIDX, we do just that. That is, the MIDX's checksum will change in
response to any perturbation of the underlying object order. In t5326,
this will cause the MIDX's checksum to update (even without changing the
set of packs in the MIDX), preventing the stale read problem.

Note that this makes it safe to continue to link(2) the MIDX .rev file
into place, since it is now impossible to have a .rev file that is
out-of-sync with the MIDX whose checksum it references. (But we will do
away with MIDX .rev files later in this series anyway, so this is
somewhat of a moot point).

In theory, it is possible to store a "fingerprint" of the full object
order here, so long as that fingerprint changes at least as often as the
full object order does. Some possibilities here include storing the
identity of the preferred pack, along with the mtimes of the
non-preferred packs in a consistent order. But storing a limited part of
the information makes it difficult to reason about whether or not there
are gaps between the two that would cause us to get bitten by this bug
again.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Reviewed-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-27 12:07:52 -08:00
Junio C Hamano
4ce498baa3 Merge branch 'en/zdiff3'
"Zealous diff3" style of merge conflict presentation has been added.

* en/zdiff3:
  update documentation for new zdiff3 conflictStyle
  xdiff: implement a zealous diff3, or "zdiff3"
2021-12-15 09:39:47 -08:00
Junio C Hamano
cdac0caddd Merge branch 'jt/midx-doc-fix'
Docfix.

* jt/midx-doc-fix:
  Doc: no midx and partial clone relation
2021-12-10 14:35:13 -08:00
Junio C Hamano
4ee5cacc16 Merge branch 'tl/midx-docfix'
Doc mark-up fix.

* tl/midx-docfix:
  midx: fix a formatting issue in "multi-pack-index.txt"
2021-12-10 14:35:11 -08:00
Junio C Hamano
83113c4268 Merge branch 'cw/protocol-v2-doc-fix'
Doc update.

* cw/protocol-v2-doc-fix:
  protocol-v2.txt: align delim-pkt spec with usage
2021-12-10 14:35:00 -08:00
Elijah Newren
ddfc44a898 update documentation for new zdiff3 conflictStyle
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-01 14:45:59 -08:00
Jonathan Tan
7d3fc7df70 Doc: no midx and partial clone relation
The multi-pack index treats promisor packfiles (that is, packfiles that
have an accompanying .promisor file) the same as other packfiles. Remove
a section in the documentation that seems to indicate otherwise.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-11-22 12:46:33 -08:00
Teng Long
ad506e6780 midx: fix a formatting issue in "multi-pack-index.txt"
There is a formatting issue  in "multi-pack-index.html", corresponding
to the nesting bulleted list of a wrong usage in "multi-pack-index.txt"
and this commit fix the problem.

In ASCIIDOC, it doesn't treat an indented character as the
beginning of a sub-list. If we want to write a nested bulleted list, we
could just use ASTERISK without any DASH like:

      "
      * Level 1 list item
      ** Level 2 list item
      *** Level 3 list item
      ** Level 2 list item
      * Level 1 list item
      ** Level 2 list item
      * Level 1 list item
      "

The DASH can be used for bulleted list too, But the DASH is suggested
only to be used as the marker for the first level because the DASH
doesn’t work well or a best practice for nested lists,
like (dash is as level 2 below):

      "
      * Level 1 list item
      - Level 2 list item
      * Level 1 list item
      "

ASTERISK is recommanded to use because it works intuitively and clearly
("marker length = nesting level") in nested lists, but the DASH can't.
However, when you want to write a non-nested bulleted lists, DASH works
too, like:

      "
      - Level 1 list item
      - Level 1 list item
      - Level 1 list item
      "

Reviewed-by: Taylor Blau <me@ttaylorr.com>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Teng Long <dyroneteng@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-11-18 11:31:07 -08:00
Junio C Hamano
5a73c6bdc7 Merge branch 'js/trace2-raise-format-version'
When we added a new event type to trace2 event stream, we forgot to
raise the format version number, which has been corrected.

* js/trace2-raise-format-version:
  trace2: increment event format version
2021-11-12 15:29:25 -08:00
Josh Steadmon
04480e67fe trace2: increment event format version
In 64bc752 (trace2: add trace2_child_ready() to report on background
children, 2021-09-20), we added a new "child_ready" event. In
Documentation/technical/api-trace2.txt, we promise that adding a new
event type will result in incrementing the trace2 event format version
number, but this was not done. Correct this in code & docs.

Signed-off-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-11-11 15:01:04 -08:00
Calvin Wan
74db416c9c protocol-v2.txt: align delim-pkt spec with usage
The current protocol EBNF allows command-request to end with the
capability list, if no command specific arguments follow, but the
protocol requires that after the capability list, there must be a
delim-pkt regardless of the number of command specific arguments.  Fixed
the EBNF to match. Both JGit and libgit2's implementation has the
delim-pkt as mandatory. JGit's code is not publicly linkable, but
libgit2 is linked below[1]. As for currently implemented commands on v2
(ls-ref and fetch), the delim packet is already being passed through

[1]: https://github.com/libgit2/libgit2/blob/main/src/transports/git.c

Reported-by: Ivan Frade <ifrade@google.com>
Signed-off-by: Calvin Wan <calvinwan@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-11-11 14:53:18 -08:00
Junio C Hamano
97ab03b12a Merge branch 'jc/doc-commit-header-continuation-line'
Doc update.

* jc/doc-commit-header-continuation-line:
  signature-format.txt: explain and illustrate multi-line headers
2021-10-25 16:07:00 -07:00
Junio C Hamano
af303ee392 Merge branch 'jh/builtin-fsmonitor-part1'
Built-in fsmonitor (part 1).

* jh/builtin-fsmonitor-part1:
  t/helper/simple-ipc: convert test-simple-ipc to use start_bg_command
  run-command: create start_bg_command
  simple-ipc/ipc-win32: add Windows ACL to named pipe
  simple-ipc/ipc-win32: add trace2 debugging
  simple-ipc: move definition of ipc_active_state outside of ifdef
  simple-ipc: preparations for supporting binary messages.
  trace2: add trace2_child_ready() to report on background children
2021-10-13 15:15:58 -07:00
Junio C Hamano
f6c013dfa1 signature-format.txt: explain and illustrate multi-line headers
A signature attached to a signed commit, and the contents of the
commit that merged a signed tag, are both recorded as a value of an
object header field as a multi-line value, and are subject to the
formatting convention for multi-line values in the headers, with a
leading SP signaling that the rest of the line is a continuation of
the previous line.  Most notably, an empty line in such a multi-line
value would result in a line with a sole SP on it.

Examples in the signature-format technical documentation include a
few of these cases but we did not show these otherwise invisible SPs
in the example.  These trailing spaces cannot be seen on display or
on paper, and forces the readers to look for them in their editors
or pagers, even if we added them to the document.

Extend the overview section to explain the multi-line value
formatting and highlight these otherwise invisible SPs by inventing
the "a dollar-sign at the end of line that appears after SP merely
signals that there is a SP there, and the dollar-sign itself does
not appear in the real file" notation, inspired by "cat -e" output,
to help readers to learn exactly where such "a single SP that is
originally an empty line" appears in the examples.

Reported-by: Rob Browning <rlb@defaultvalue.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-12 19:06:24 -07:00
Junio C Hamano
b39b0e1a82 Merge branch 'ew/midx-doc-update'
Doc tweak.

* ew/midx-doc-update:
  doc/technical: update note about core.multiPackIndex
2021-10-06 13:40:12 -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
Eric Wong
0d0d8d8a11 doc/technical: update note about core.multiPackIndex
MIDX files are used by default since commit 18e449f86b
(midx: enable core.multiPackIndex by default, 2020-09-25)

Helped-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Eric Wong <e@80x24.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-24 08:39:53 -07:00
Junio C Hamano
0e35107e7d Merge branch 'ab/retire-option-argument'
An oddball OPTION_ARGUMENT feature has been removed from the
parse-options API.

* ab/retire-option-argument:
  parse-options API: remove OPTION_ARGUMENT feature
  difftool: use run_command() API in run_file_diff()
  difftool: prepare "diff" cmdline in cmd_difftool()
  difftool: prepare "struct child_process" in cmd_difftool()
2021-09-23 13:44:48 -07:00
Junio C Hamano
cabb41d0f6 Merge branch 'jk/http-server-protocol-versions'
Taking advantage of the CGI interface, http-backend has been
updated to enable protocol v2 automatically when the other side
asks for it.

* jk/http-server-protocol-versions:
  docs/protocol-v2: point readers transport config discussion
  docs/git: discuss server-side config for GIT_PROTOCOL
  docs/http-backend: mention v2 protocol
  http-backend: handle HTTP_GIT_PROTOCOL CGI variable
  t5551: test v2-to-v0 http protocol fallback
2021-09-23 13:44:47 -07:00
Junio C Hamano
5331af2352 Merge branch 'ab/serve-cleanup'
Code clean-up around "git serve".

* ab/serve-cleanup:
  upload-pack: document and rename --advertise-refs
  serve.[ch]: remove "serve_options", split up --advertise-refs code
  {upload,receive}-pack tests: add --advertise-refs tests
  serve.c: move version line to advertise_capabilities()
  serve: move transfer.advertiseSID check into session_id_advertise()
  serve.[ch]: don't pass "struct strvec *keys" to commands
  serve: use designated initializers
  transport: use designated initializers
  transport: rename "fetch" in transport_vtable to "fetch_refs"
  serve: mark has_capability() as static
2021-09-20 15:20:43 -07:00
Junio C Hamano
0649303820 Merge branch 'tb/multi-pack-bitmaps'
The reachability bitmap file used to be generated only for a single
pack, but now we've learned to generate bitmaps for history that
span across multiple packfiles.

* tb/multi-pack-bitmaps: (29 commits)
  pack-bitmap: drop bitmap_index argument from try_partial_reuse()
  pack-bitmap: drop repository argument from prepare_midx_bitmap_git()
  p5326: perf tests for MIDX bitmaps
  p5310: extract full and partial bitmap tests
  midx: respect 'GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP'
  t7700: update to work with MIDX bitmap test knob
  t5319: don't write MIDX bitmaps in t5319
  t5310: disable GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP
  t0410: disable GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP
  t5326: test multi-pack bitmap behavior
  t/helper/test-read-midx.c: add --checksum mode
  t5310: move some tests to lib-bitmap.sh
  pack-bitmap: write multi-pack bitmaps
  pack-bitmap: read multi-pack bitmaps
  pack-bitmap.c: avoid redundant calls to try_partial_reuse
  pack-bitmap.c: introduce 'bitmap_is_preferred_refname()'
  pack-bitmap.c: introduce 'nth_bitmap_object_oid()'
  pack-bitmap.c: introduce 'bitmap_num_objects()'
  midx: avoid opening multiple MIDXs when writing
  midx: close linked MIDXs, avoid leaking memory
  ...
2021-09-20 15:20:39 -07:00
Jeff Hostetler
64bc75244b trace2: add trace2_child_ready() to report on background children
Create "child_ready" event to capture the state of a child process
created in the background.

When a child command is started a "child_start" event is generated in
the Trace2 log.  For normal synchronous children, a "child_exit" event
is later generated when the child exits or is terminated.  The two events
include information, such as the "child_id" and "pid", to allow post
analysis to match-up the command line and exit status.

When a child is started in the background (and may outlive the parent
process), it is not possible for the parent to emit a "child_exit"
event.  Create a new "child_ready" event to indicate whether the
child was successfully started.  Also include the "child_id" and "pid"
to allow similar post processing.

This will be used in a later commit with the new "start_bg_command()".

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-20 08:57:58 -07:00
Jeff King
9db5fb4fb3 docs/protocol-v2: clarify some ls-refs ref-prefix details
We've never documented the fact that a client can provide multiple
ref-prefix capabilities. Let's describe the behavior.

We also never discussed the "best effort" nature of the prefixes. The
client side of git.git has always treated them this way, filtering the
result with local patterns. And indeed any client must do this, because
the prefix patterns are not sufficient to express the usual refspecs
(and so for "foo" we ask for "refs/heads/foo", "refs/tags/foo", and so
on).

So this may be considered a change in the spec with respect to client
expectations / requirements, but it's mostly codifying existing
behavior.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-15 12:25:19 -07:00
Junio C Hamano
0057847208 Merge branch 'ab/serve-cleanup' into jk/reduce-malloc-in-v2-servers
* ab/serve-cleanup:
  upload-pack: document and rename --advertise-refs
  serve.[ch]: remove "serve_options", split up --advertise-refs code
  {upload,receive}-pack tests: add --advertise-refs tests
  serve.c: move version line to advertise_capabilities()
  serve: move transfer.advertiseSID check into session_id_advertise()
  serve.[ch]: don't pass "struct strvec *keys" to commands
  serve: use designated initializers
  transport: use designated initializers
  transport: rename "fetch" in transport_vtable to "fetch_refs"
  serve: mark has_capability() as static
2021-09-14 10:56:05 -07:00
Ævar Arnfjörð Bjarmason
4c25356e0e parse-options API: remove OPTION_ARGUMENT feature
As was noted in 1a85b49b87 (parse-options: make OPT_ARGUMENT() more
useful, 2019-03-14) there's only ever been one user of the
OPT_ARGUMENT(), that user was added in 20de316e33 (difftool: allow
running outside Git worktrees with --no-index, 2019-03-14).

The OPT_ARGUMENT() feature itself was added way back in
580d5bffde (parse-options: new option type to treat an option-like
parameter as an argument., 2008-03-02), but as discussed in
1a85b49b87 wasn't used until 20de316e33 in 2019.

Now that the preceding commit has migrated this code over to using
"struct strvec" to manage the "args" member of a "struct
child_process", we can just use that directly instead of relying on
OPT_ARGUMENT.

This has a minor change in behavior in that if we'll pass --no-index
we'll now always pass it as the first argument, before we'd pass it in
whatever position the caller did. Preserving this was the real value
of OPT_ARGUMENT(), but as it turns out we didn't need that either. We
can always inject it as the first argument, the other end will parse
it just the same.

Note that we cannot remove the "out" and "cpidx" members of "struct
parse_opt_ctx_t" added in 580d5bffde, while they were introduced with
OPT_ARGUMENT() we since used them for other things.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-12 23:27:38 -07:00