Introduce a new extension "refstorage" so that we can mark a
repository that uses a non-default ref backend, like reftable.
* ps/refstorage-extension:
t9500: write "extensions.refstorage" into config
builtin/clone: introduce `--ref-format=` value flag
builtin/init: introduce `--ref-format=` value flag
builtin/rev-parse: introduce `--show-ref-format` flag
t: introduce GIT_TEST_DEFAULT_REF_FORMAT envvar
setup: introduce GIT_DEFAULT_REF_FORMAT envvar
setup: introduce "extensions.refStorage" extension
setup: set repository's formats on init
setup: start tracking ref storage format
refs: refactor logic to look up storage backends
worktree: skip reading HEAD when repairing worktrees
t: introduce DEFAULT_REPO_FORMAT prereq
Streaming spans of packfile data used to be done only from a
single, primary, pack in a repository with multiple packfiles. It
has been extended to allow reuse from other packfiles, too.
* tb/multi-pack-verbatim-reuse: (26 commits)
t/perf: add performance tests for multi-pack reuse
pack-bitmap: enable reuse from all bitmapped packs
pack-objects: allow setting `pack.allowPackReuse` to "single"
t/test-lib-functions.sh: implement `test_trace2_data` helper
pack-objects: add tracing for various packfile metrics
pack-bitmap: prepare to mark objects from multiple packs for reuse
pack-revindex: implement `midx_pair_to_pack_pos()`
pack-revindex: factor out `midx_key_to_pack_pos()` helper
midx: implement `midx_preferred_pack()`
git-compat-util.h: implement checked size_t to uint32_t conversion
pack-objects: include number of packs reused in output
pack-objects: prepare `write_reused_pack_verbatim()` for multi-pack reuse
pack-objects: prepare `write_reused_pack()` for multi-pack reuse
pack-objects: pass `bitmapped_pack`'s to pack-reuse functions
pack-objects: keep track of `pack_start` for each reuse pack
pack-objects: parameterize pack-reuse routines over a single pack
pack-bitmap: return multiple packs via `reuse_partial_packfile_from_bitmap()`
pack-bitmap: simplify `reuse_partial_packfile_from_bitmap()` signature
ewah: implement `bitmap_is_empty()`
pack-bitmap: pass `bitmapped_pack` struct to pack-reuse functions
...
Since commit 62db5247 (rebase -i: generate the script via
rebase--helper, 2017-07-14), the short hash is given in
rebase-todo. Specifying rebase.instructionFormat does not alter this
behavior, contrary to what the documentation implies.
Signed-off-by: Maarten van der Schrieck <maarten@thingsconnected.nl>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Doc updates to clarify what an "unborn branch" means.
* jc/orphan-unborn:
orphan/unborn: fix use of 'orphan' in end-user facing messages
orphan/unborn: add to the glossary and use them consistently
Introduce a new "extensions.refStorage" extension that allows us to
specify the ref storage format used by a repository. For now, the only
supported format is the "files" format, but this list will likely soon
be extended to also support the upcoming "reftable" format.
There have been discussions on the Git mailing list in the past around
how exactly this extension should look like. One alternative [1] that
was discussed was whether it would make sense to model the extension in
such a way that backends are arbitrarily stackable. This would allow for
a combined value of e.g. "loose,packed-refs" or "loose,reftable", which
indicates that new refs would be written via "loose" files backend and
compressed into "packed-refs" or "reftable" backends, respectively.
It is arguable though whether this flexibility and the complexity that
it brings with it is really required for now. It is not foreseeable that
there will be a proliferation of backends in the near-term future, and
the current set of existing formats and formats which are on the horizon
can easily be configured with the much simpler proposal where we have a
single value, only.
Furthermore, if we ever see that we indeed want to gain the ability to
arbitrarily stack the ref formats, then we can adapt the current
extension rather easily. Given that Git clients will refuse any unknown
value for the "extensions.refStorage" extension they would also know to
ignore a stacked "loose,packed-refs" in the future.
So let's stick with the easy proposal for the time being and wire up the
extension.
[1]: <pull.1408.git.1667846164.gitgitgadget@gmail.com>
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There is no 'ref/notes/' hierarchy. '[format] notes = foo' uses notes
that are found in 'refs/notes/foo'.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Now that both the pack-bitmap and pack-objects code are prepared to
handle marking and using objects from multiple bitmapped packs for
verbatim reuse, allow marking objects from all bitmapped packs as
eligible for reuse.
Within the `reuse_partial_packfile_from_bitmap()` function, we no longer
only mark the pack whose first object is at bit position zero for reuse,
and instead mark any pack contained in the MIDX as a reuse candidate.
Provide a handful of test cases in a new script (t5332) exercising
interesting behavior for multi-pack reuse to ensure that we performed
all of the previous steps correctly.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In e704fc7978 (pack-objects: introduce pack.allowPackReuse, 2019-12-18),
the `pack.allowPackReuse` configuration option was introduced, allowing
users to disable the pack reuse mechanism.
To prepare for debugging multi-pack reuse, allow setting configuration
to "single" in addition to the usual bool-or-int values.
"single" implies the same behavior as "true", "1", "yes", and so on. But
it will complement a new "multi" value (to be introduced in a future
commit). When set to "single", we will only perform pack reuse on a
single pack, regardless of whether or not there are multiple MIDX'd
packs.
This requires no code changes (yet), since we only support single pack
reuse.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
To orphan is a verb that denotes the act of getting on an unborn
branch, and a few references to "orphan branch" in our documentation
are misuses of the word. They caused end-user confusion, which was
made even worse because we did not have the term defined in the
glossary document. Add entries for "unborn" branch and "orphan"
operation to the glossary, and adjust existing documentation
accordingly.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Setting the rebase.autoSquash config variable to true implies a couple
of restrictions: it prevents preemptive fast-forwarding and it triggers
conflicts with apply backend options. However, it only actually results
in auto-squashing when combined with the --interactive (or -i) option,
due to code in run_specific_rebase() that disables auto-squashing unless
the REBASE_INTERACTIVE_EXPLICIT flag is set.
Doing autosquashing for rebase.autoSquash without --interactive would be
problematic in terms of backward compatibility, but conversely, there is
no need for the aforementioned restrictions without --interactive.
So drop the options.config_autosquash check from the conditions for
clearing allow_preemptive_ff, as the case where it is combined with
--interactive is already covered by the REBASE_INTERACTIVE_EXPLICIT
flag check above it.
Also drop the "apply options are incompatible with rebase.autoSquash"
error, because it is unreachable if it is restricted to --interactive,
as apply options already cause an error when used with --interactive.
Drop the tests for the error from t3422-rebase-incompatible-options.sh,
which has separate tests for the conflicts of --interactive with apply
options.
When neither --autosquash nor --no-autosquash are given, only set
options.autosquash to true if rebase.autosquash is combined with
--interactive.
Don't initialize options.config_autosquash to -1, as there is no need to
distinguish between rebase.autoSquash being unset or explicitly set to
false.
Finally, amend the rebase.autoSquash documentation to say it only
affects interactive mode.
Signed-off-by: Andy Koppe <andy.koppe@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The attribute subsystem learned to honor `attr.tree` configuration
that specifies which tree to read the .gitattributes files from.
* jc/attr-tree-config:
attr: add attr.tree for setting the treeish to read attributes from
attr: read attributes from HEAD when bare repo
Many typos, ungrammatical sentences and wrong phrasing have been
fixed.
* sn/typo-grammo-phraso-fixes:
t/README: fix multi-prerequisite example
doc/gitk: s/sticked/stuck/
git-jump: admit to passing merge mode args to ls-files
doc/diff-options: improve wording of the log.diffMerges mention
doc: fix some typos, grammar and wording issues
"git repack" learned "--max-cruft-size" to prevent cruft packs from
growing without bounds.
* tb/repack-max-cruft-size:
repack: free existing_cruft array after use
builtin/repack.c: avoid making cruft packs preferred
builtin/repack.c: implement support for `--max-cruft-size`
builtin/repack.c: parse `--max-pack-size` with OPT_MAGNITUDE
t7700: split cruft-related tests to t7704
44451a2 (attr: teach "--attr-source=<tree>" global option to "git",
2023-05-06) provided the ability to pass in a treeish as the attr
source. In the context of serving Git repositories as bare repos like we
do at GitLab however, it would be easier to point --attr-source to HEAD
for all commands by setting it once.
Add a new config attr.tree that allows this.
Signed-off-by: John Cai <johncai86@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Cruft packs are an alternative mechanism for storing a collection of
unreachable objects whose mtimes are recent enough to avoid being
pruned out of the repository.
When cruft packs were first introduced back in b757353676
(builtin/pack-objects.c: --cruft without expiration, 2022-05-20) and
a7d493833f (builtin/pack-objects.c: --cruft with expiration,
2022-05-20), the recommended workflow consisted of:
- Repacking periodically, either by packing anything loose in the
repository (via `git repack -d`) or producing a geometric sequence
of packs (via `git repack --geometric=<d> -d`).
- Every so often, splitting the repository into two packs, one cruft
to store the unreachable objects, and another non-cruft pack to
store the reachable objects.
Repositories may (out of band with the above) choose periodically to
prune out some unreachable objects which have aged out of the grace
period by generating a pack with `--cruft-expiration=<approxidate>`.
This allowed repositories to maintain relatively few packs on average,
and quarantine unreachable objects together in a cruft pack, avoiding
the pitfalls of holding unreachable objects as loose while they age out
(for more, see some of the details in 3d89a8c118
(Documentation/technical: add cruft-packs.txt, 2022-05-20)).
This all works, but can be costly from an I/O-perspective when
frequently repacking a repository that has many unreachable objects.
This problem is exacerbated when those unreachable objects are rarely
(if every) pruned.
Since there is at most one cruft pack in the above scheme, each time we
update the cruft pack it must be rewritten from scratch. Because much of
the pack is reused, this is a relatively inexpensive operation from a
CPU-perspective, but is very costly in terms of I/O since we end up
rewriting basically the same pack (plus any new unreachable objects that
have entered the repository since the last time a cruft pack was
generated).
At the time, we decided against implementing more robust support for
multiple cruft packs. This patch implements that support which we were
lacking.
Introduce a new option `--max-cruft-size` which allows repositories to
accumulate cruft packs up to a given size, after which point a new
generation of cruft packs can accumulate until it reaches the maximum
size, and so on. To generate a new cruft pack, the process works like
so:
- Sort a list of any existing cruft packs in ascending order of pack
size.
- Starting from the beginning of the list, group cruft packs together
while the accumulated size is smaller than the maximum specified
pack size.
- Combine the objects in these cruft packs together into a new cruft
pack, along with any other unreachable objects which have since
entered the repository.
Once a cruft pack grows beyond the size specified via `--max-cruft-size`
the pack is effectively frozen. This limits the I/O churn up to a
quadratic function of the value specified by the `--max-cruft-size`
option, instead of behaving quadratically in the number of total
unreachable objects.
When pruning unreachable objects, we bypass the new code paths which
combine small cruft packs together, and instead start from scratch,
passing in the appropriate `--max-pack-size` down to `pack-objects`,
putting it in charge of keeping the resulting set of cruft packs sized
correctly.
This may seem like further I/O churn, but in practice it isn't so bad.
We could prune old cruft packs for whom all or most objects are removed,
and then generate a new cruft pack with just the remaining set of
objects. But this additional complexity buys us relatively little,
because most objects end up being pruned anyway, so the I/O churn is
well contained.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A previous commit implemented the `gc.repackFilter` config option
to specify a filter that should be used by `git gc` when
performing repacks.
Another previous commit has implemented
`git repack --filter-to=<dir>` to specify the location of the
packfile containing filtered out objects when using a filter.
Let's implement the `gc.repackFilterTo` config option to specify
that location in the config when `gc.repackFilter` is used.
Now when `git gc` will perform a repack with a <dir> configured
through this option and not empty, the repack process will be
passed a corresponding `--filter-to=<dir>` argument.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A previous commit has implemented `git repack --filter=<filter-spec>` to
allow users to filter out some objects from the main pack and move them
into a new different pack.
Users might want to perform such a cleanup regularly at the same time as
they perform other repacks and cleanups, so as part of `git gc`.
Let's allow them to configure a <filter-spec> for that purpose using a
new gc.repackFilter config option.
Now when `git gc` will perform a repack with a <filter-spec> configured
through this option and not empty, the repack process will be passed a
corresponding `--filter=<filter-spec>` argument.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add new configuration option diff.statNameWidth=<width> that is equivalent
to the command-line option --stat-name-width=<width>, but it is ignored
by format-patch. This follows the logic established by the already
existing configuration option diff.statGraphWidth=<width>.
Limiting the widths of names and graphs in the --stat output makes sense
for interactive work on wide terminals with many columns, hence the support
for these configuration options. They don't affect format-patch because
it already adheres to the traditional 80-column standard.
Update the documentation and add more tests to cover new configuration
option diff.statNameWidth=<width>. While there, perform a few minor code
and whitespace cleanups here and there, as spotted.
Signed-off-by: Dragan Simic <dsimic@manjaro.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We now limit depth of the tree objects and maximum length of
pathnames recorded in tree objects.
* jk/tree-name-and-depth-limit:
lower core.maxTreeDepth default to 2048
tree-diff: respect max_allowed_tree_depth
list-objects: respect max_allowed_tree_depth
read_tree(): respect max_allowed_tree_depth
traverse_trees(): respect max_allowed_tree_depth
add core.maxTreeDepth config
fsck: detect very large tree pathnames
tree-walk: rename "error" variable
tree-walk: drop MAX_TRAVERSE_TREES macro
tree-walk: reduce stack size for recursive functions
Most of our tree traversal algorithms use recursion to visit sub-trees.
For pathologically large trees, this can cause us to run out of stack
space and abort in an uncontrolled way. Let's put our own limit here so
that we can fail gracefully rather than segfaulting.
In similar cases where we recursed along the commit graph, we rewrote
the algorithms to avoid recursion and keep any stack data on the heap.
But the commit graph is meant to grow without bound, whereas it's not an
imposition to put a limit on the maximum size of tree we'll handle.
And this has a bonus side effect: coupled with a limit on individual
tree entry names, this limits the total size of a path we may encounter.
This gives us an extra protection against code handling long path names
which may suffer from integer overflows in the size (which could then be
exploited by malicious trees).
The default of 4096 is set to be much longer than anybody would care
about in the real world. Even with single-letter interior tree names
(like "a/b/c"), such a path is at least 8191 bytes. While most operating
systems will let you create such a path incrementally, trying to
reference the whole thing in a system call (as Git would do when
actually trying to access it) will result in ENAMETOOLONG. Coupled with
the recent fsck.largePathname warning, the maximum total pathname Git
will handle is (by default) 16MB.
This config option doesn't do anything yet; future patches will convert
various algorithms to respect the limit.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Overly long label names used in the sequencer machinery are now
chopped to fit under filesystem limitation.
* mp/rebase-label-length-limit:
rebase: allow overriding the maximal length of the generated labels
sequencer: truncate labels to accommodate loose refs
With this change, users can override the compiled-in default for the
maximal length of the label names generated by `git rebase
--rebase-merges`.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Mark Ruvald Pedersen <mped@demant.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git pack-objects" learned to invoke a new hook program that
enumerates extra objects to be used as anchoring points to keep
otherwise unreachable objects in cruft packs.
* tb/gc-recent-object-hook:
gc: introduce `gc.recentObjectsHook`
reachable.c: extract `obj_is_recent()`
The object traversal using reachability bitmap done by
"pack-object" has been tweaked to take advantage of the fact that
using "boundary" commits as representative of all the uninteresting
ones can save quite a lot of object enumeration.
* tb/pack-bitmap-traversal-with-boundary:
pack-bitmap.c: use commit boundary during bitmap traversal
pack-bitmap.c: extract `fill_in_bitmap()`
object: add object_array initializer helper function
'git worktree add' learned how to create a worktree based on an
orphaned branch with `--orphan`.
* ja/worktree-orphan:
worktree add: emit warn when there is a bad HEAD
worktree add: extend DWIM to infer --orphan
worktree add: introduce "try --orphan" hint
worktree add: add --orphan flag
t2400: add tests to verify --quiet
t2400: refactor "worktree add" opt exclusion tests
t2400: cleanup created worktree in test
worktree add: include -B in usage docs
This patch introduces a new multi-valued configuration option,
`gc.recentObjectsHook` as a means to mark certain objects as recent (and
thus exempt from garbage collection), regardless of their age.
When performing a garbage collection operation on a repository with
unreachable objects, Git makes its decision on what to do with those
object(s) based on how recent the objects are or not. Generally speaking,
unreachable-but-recent objects stay in the repository, and older objects
are discarded.
However, we have no convenient way to keep certain precious, unreachable
objects around in the repository, even if they have aged out and would
be pruned. Our options today consist of:
- Point references at the reachability tips of any objects you
consider precious, which may be undesirable or infeasible if there
are many such objects.
- Track them via the reflog, which may be undesirable since the
reflog's lifetime is limited to that of the reference it's tracking
(and callers may want to keep those unreachable objects around for
longer).
- Extend the grace period, which may keep around other objects that
the caller *does* want to discard.
- Manually modify the mtimes of objects you want to keep. If those
objects are already loose, this is easy enough to do (you can just
enumerate and `touch -m` each one).
But if they are packed, you will either end up modifying the mtimes
of *all* objects in that pack, or be forced to write out a loose
copy of that object, both of which may be undesirable. Even worse,
if they are in a cruft pack, that requires modifying its `*.mtimes`
file by hand, since there is no exposed plumbing for this.
- Force the caller to construct the pack of objects they want
to keep themselves, and then mark the pack as kept by adding a
".keep" file. This works, but is burdensome for the caller, and
having extra packs is awkward as you roll forward your cruft pack.
This patch introduces a new option to the above list via the
`gc.recentObjectsHook` configuration, which allows the caller to
specify a program (or set of programs) whose output is treated as a set
of objects to treat as recent, regardless of their true age.
The implementation is straightforward. Git enumerates recent objects via
`add_unseen_recent_objects_to_traversal()`, which enumerates loose and
packed objects, and eventually calls add_recent_object() on any objects
for which `want_recent_object()`'s conditions are met.
This patch modifies the recency condition from simply "is the mtime of
this object more recent than the cutoff?" to "[...] or, is this object
mentioned by at least one `gc.recentObjectsHook`?".
Depending on whether or not we are generating a cruft pack, this allows
the caller to do one of two things:
- If generating a cruft pack, the caller is able to retain additional
objects via the cruft pack, even if they would have otherwise been
pruned due to their age.
- If not generating a cruft pack, the caller is likewise able to
retain additional objects as loose.
A potential alternative here is to introduce a new mode to alter the
contents of the reachable pack instead of the cruft one. One could
imagine a new option to `pack-objects`, say `--extra-reachable-tips`
that does the same thing as above, adding the visited set of objects
along the traversal to the pack.
But this has the unfortunate side-effect of altering the reachability
closure of that pack. If parts of the unreachable object graph mentioned
by one or more of the "extra reachable tips" programs is not closed,
then the resulting pack won't be either. This makes it impossible in the
general case to write out reachability bitmaps for that pack, since
closure is a requirement there.
Instead, keep these unreachable objects in the cruft pack (or set of
unreachable, loose objects) instead, to ensure that we can continue to
have a pack containing just reachable objects, which is always safe to
write a bitmap over.
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
