The "diagnose" feature to create a zip archive for diagnostic
material has been lifted from "scalar" and made into a feature of
"git bugreport".
* vd/scalar-generalize-diagnose:
scalar: update technical doc roadmap
scalar-diagnose: use 'git diagnose --mode=all'
builtin/bugreport.c: create '--diagnose' option
builtin/diagnose.c: add '--mode' option
builtin/diagnose.c: create 'git diagnose' builtin
diagnose.c: add option to configure archive contents
scalar-diagnose: move functionality to common location
scalar-diagnose: move 'get_disk_info()' to 'compat/'
scalar-diagnose: add directory to archiver more gently
scalar-diagnose: avoid 32-bit overflow of size_t
scalar-diagnose: use "$GIT_UNZIP" in test
Expose a lot of "tech docs" via "git help" interface.
* ab/tech-docs-to-help:
docs: move http-protocol docs to man section 5
docs: move cruft pack docs to gitformat-pack
docs: move pack format docs to man section 5
docs: move signature docs to man section 5
docs: move index format docs to man section 5
docs: move protocol-related docs to man section 5
docs: move commit-graph format docs to man section 5
git docs: add a category for file formats, protocols and interfaces
git docs: add a category for user-facing file, repo and command UX
git help doc: use "<doc>" instead of "<guide>"
help.c: remove common category behavior from drop_prefix() behavior
help.c: refactor drop_prefix() to use a "switch" statement"
Update the Scalar roadmap to reflect the completion of generalizing 'scalar
diagnose' into 'git diagnose' and 'git bugreport --diagnose'.
Signed-off-by: Victoria Dye <vdye@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The previous change introduced the bundle URI design document. It
creates a flexible set of options that allow bundle providers many ways
to organize Git object data and speed up clones and fetches. It is
particularly important that we have flexibility so we can apply future
advancements as new ideas for efficiently organizing Git data are
discovered.
However, the design document does not provide even an example of how
bundles could be organized, and that makes it difficult to envision how
the feature should work at the end of the implementation plan.
Add a section that details how a bundle provider could work, including
using the Git server advertisement for multiple geo-distributed servers.
This organization is based on the GVFS Cache Servers which have
successfully used similar ideas to provide fast object access and
reduced server load for very large repositories.
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce the idea of bundle URIs to the Git codebase through an
aspirational design document. This document includes the full design
intended to include the feature in its fully-implemented form. This will
take several steps as detailed in the Implementation Plan section.
By committing this document now, it can be used to motivate changes
necessary to reach these final goals. The design can still be altered as
new information is discovered.
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Continue the move of existing Documentation/technical/* protocol and
file-format documentation into our main documentation space by moving
the http-protocol.txt documentation over. I'm renaming it to
"protocol-http" to be consistent with other things in the new
gitformat-protocol-* namespace.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Integrate the cruft packs documentation initially added in
3d89a8c118 (Documentation/technical: add cruft-packs.txt, 2022-05-20)
to the newly created "gitformat-pack" documentation.
Like the "bitmap-format" added before it in
0d4455a3ab (documentation: add documentation for the bitmap format,
2013-11-14) the "cruft-packs" were documented in their own file.
As the diff move detection will show there is no change to
"Documentation/technical/cruft-packs.txt" here except to move it, and
to "indent" the existing sections by adding an extra "=" to them.
We could similarly convert the "bitmap-format.txt", but let's leave it
for now due to a conflict with the in-flight ac/bitmap-lookup-table
series.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Continue the move of existing Documentation/technical/* protocol and
file-format documentation into our main documentation space by moving
the various documentation pertaining to the *.pack format and related
files, and updating things that refer to it to link to the new
location.
By moving these we can properly link from the newly created
gitformat-commit-graph to a gitformat-chunk-format page.
Integrating "Documentation/technical/bitmap-format.txt" and
"Documentation/technical/cruft-packs.txt" might logically be part of
this change, but as those cover parts of the wider "pack
format" (including associated files) that's documented outside of
"Documentation/technical/pack-format.txt" let's leave those for now,
subsequent commit(s) will address those.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Continue the move of existing Documentation/technical/* protocol and
file-format documentation into our main documentation space by moving
the signature format documentation.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Continue the move of existing Documentation/technical/* protocol and
file-format documentation into our main documentation space by moving
the index format documentation.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Continue the move of existing Documentation/technical/* protocol and
file-format documentation into our main documentation space. By moving
the things that discuss the protocol we can properly link from
e.g. lsrefs.unborn and protocol.version documentation to a manpage we
build by default.
So far we have been using the "gitformat-" prefix for the
documentation we've been moving over from Documentation/technical/*,
but for protocol documentation let's use "gitprotocol-*".
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Continue the move of existing Documentation/technical/* protocol and
file-format documentation into our main documentation space.
By moving the documentation for the commit-graph format into man
section 5 and the new "developerinterfaces" category. This change is
split from subsequent commits due to the relatively large amount of
ASCIIDOC formatting changes that are required.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Create a new "File formats, protocols and other developer interfaces"
section in the main "git help git" manual page and start moving the
documentation that now lives in "Documentation/technical/*.git" over
to it. This complements the newly added and adjacent "Repository,
command and file interfaces" section.
This makes the technical documentation more accessible and
discoverable. Before this we wouldn't install it by default, and had
no ability to build man page versions of them. The links to them from
our existing documentation link to the generated HTML version of these
docs.
So let's start moving those over, starting with just the
"bundle-format.txt" documentation added in 7378ec90e1 (doc: describe
Git bundle format, 2020-02-07). We'll now have a new
gitformat-bundle(5) man page. Subsequent commits will move more git
internal format documentation over.
Unfortunately the syntax of the current Documentation/technical/*.txt
is not the same (when it comes to section headings etc.) as our
Documentation/*.txt documentation, so change the relevant bits of
syntax as we're moving this over.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Adapt the content from 'contrib/scalar/README.md' into a design document in
'Documentation/technical/'. In addition to reformatting for asciidoc,
elaborate on the background, purpose, and design choices that went into
Scalar.
Most of this document will persist in the 'Documentation/technical/' after
Scalar has been moved out of 'contrib/' and into the root of Git. Until that
time, it will also contain a temporary "Roadmap" section detailing the
remaining series needed to finish the initial version of Scalar. The section
will be removed once Scalar is moved to the repo root, but in the meantime
serves as a guide for readers to keep up with progress on the feature.
Signed-off-by: Victoria Dye <vdye@github.com>
Acked-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The first section of 'Documentation/technical/index-format.txt'
mentions that "Git currently supports cache tree and resolve undo
extensions", but then goes on, and in the "Extensions" section
describes not only these two, but six other extensions [1].
Remove this sentence, as it's misleading about the status of all those
other extensions.
Alternatively we could keep that sentence and update the list of
extensions, but that might well lead to a recurring issue, because
apparently this list is never updated when a new index extension is
added.
[1] Split index, untracked cache, FS monitor cache, end of index
entry, index entry offset table and sparse directory entries.
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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
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>
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>
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
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
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>
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>
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>
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>
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>
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>
"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
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>
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
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
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>
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>
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>
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>
"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"
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>
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>
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
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>
