We have two different repacking strategies in Git:
- The "gc" strategy uses git-gc(1).
- The "incremental" strategy uses multi-pack indices and `git
multi-pack-index repack` to merge together smaller packfiles as
determined by a specific batch size.
The former strategy is our old and trusted default, whereas the latter
has historically been used for our scheduled maintenance. But both
strategies have their shortcomings:
- The "gc" strategy performs regular all-into-one repacks. Furthermore
it is rather inflexible, as it is not easily possible for a user to
enable or disable specific subtasks.
- The "incremental" strategy is not a full replacement for the "gc"
strategy as it doesn't know to prune stale data.
So today, we don't have a strategy that is well-suited for large repos
while being a full replacement for the "gc" strategy.
Introduce a new "geometric" strategy that aims to fill this gap. This
strategy invokes all the usual cleanup tasks that git-gc(1) does like
pruning reflogs and rerere caches as well as stale worktrees. But where
it differs from both the "gc" and "incremental" strategy is that it uses
our geometric repacking infrastructure exposed by git-repack(1) to
repack packfiles. The advantage of geometric repacking is that we only
need to perform an all-into-one repack when the object count in a repo
has grown significantly.
One downside of this strategy is that pruning of unreferenced objects is
not going to happen regularly anymore. Every geometric repack knows to
soak up all loose objects regardless of their reachability, and merging
two or more packs doesn't consider reachability, either. Consequently,
the number of unreachable objects will grow over time.
This is remedied by doing an all-into-one repack instead of a geometric
repack whenever we determine that the geometric repack would end up
merging all packfiles anyway. This all-into-one repack then performs our
usual reachability checks and writes unreachable objects into a cruft
pack. As cruft packs won't ever be merged during geometric repacks we
can thus phase out these objects over time.
Of course, this still means that we retain unreachable objects for far
longer than with the "gc" strategy. But the maintenance strategy is
intended especially for large repositories, where the basic assumption
is that the set of unreachable objects will be significantly dwarfed by
the number of reachable objects.
If this assumption is ever proven to be too disadvantageous we could for
example introduce a time-based strategy: if the largest packfile has not
been touched for longer than $T, we perform an all-into-one repack. But
for now, such a mechanism is deferred into the future as it is not clear
yet whether it is needed in the first place.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Acked-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
While the user can pick the "incremental" maintenance strategy, it is
not possible to explicitly use the "gc" strategy. This has two
downsides:
- It is impossible to use the default "gc" strategy for a specific
repository when the strategy was globally set to a different strategy.
- It is not possible to use git-gc(1) for scheduled maintenance.
Address these issues by making making the "gc" strategy configurable.
Furthermore, extend the strategy so that git-gc(1) runs for both manual
and scheduled maintenance.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Acked-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The "maintenance.strategy" configuration allows users to configure how
Git is supposed to perform repository maintenance. The idea is that we
provide a set of high-level strategies that may be useful in different
contexts, like for example when handling a large monorepo. Furthermore,
the strategy can be tweaked by the user by overriding specific tasks.
In its current form though, the strategy only applies to scheduled
maintenance. This creates something of a gap, as scheduled and manual
maintenance will now use _different_ strategies as the latter would
continue to use git-gc(1) by default. This makes the strategies way less
useful than they could be on the one hand. But even more importantly,
the two different strategies might clash with one another, where one of
the strategies performs maintenance in such a way that it discards
benefits from the other strategy.
So ideally, it should be possible to pick one strategy that then applies
globally to all the different ways that we perform maintenance. This
doesn't necessarily mean that the strategy always does the _same_ thing
for every maintenance type. But it means that the strategy can configure
the different types to work in tandem with each other.
Change the meaning of "maintenance.strategy" accordingly so that the
strategy is applied to both types, manual and scheduled. As preceding
commits have introduced logic to run maintenance tasks depending on this
type we can tweak strategies so that they perform those tasks depending
on the context.
Note that this raises the question of backwards compatibility: when the
user has configured the "incremental" strategy we would have ignored
that strategy beforehand. Instead, repository maintenance would have
continued to use git-gc(1) by default.
But luckily, we can match that behaviour by:
- Keeping all current tasks of the incremental strategy as
`MAINTENANCE_TYPE_SCHEDULED`. This ensures that those tasks will not
run during manual maintenance.
- Configuring the "gc" task so that it is invoked during manual
maintenance.
Like this, the user shouldn't observe any difference in behaviour.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Acked-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The geometric repacking task uses a factor of two for its geometric
sequence, meaning that each next pack must contain at least twice as
many objects as the next-smaller one. In some cases it may be helpful to
configure this factor though to reduce the number of packfile merges
even further, e.g. in very big repositories. But while git-repack(1)
itself supports doing this, the maintenance task does not give us a way
to tune it.
Introduce a new "maintenance.geometric-repack.splitFactor" configuration
to plug this gap.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Acked-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce a new "geometric-repack" task. This task uses our geometric
repack infrastructure as provided by git-repack(1) itself, which is a
strategy that especially hosting providers tend to use to amortize the
costs of repacking objects.
There is one issue though with geometric repacks, namely that they
unconditionally pack all loose objects, regardless of whether or not
they are reachable. This is done because it means that we can completely
skip the reachability step, which significantly speeds up the operation.
But it has the big downside that we are unable to expire objects over
time.
To address this issue we thus use a split strategy in this new task:
whenever a geometric repack would merge together all packs, we instead
do an all-into-one repack. By default, these all-into-one repacks have
cruft packs enabled, so unreachable objects would now be written into
their own pack. Consequently, they won't be soaked up during geometric
repacking anymore and can be expired with the next full repack, assuming
that their expiry date has surpassed.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Acked-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The stash.index configuration variable can be set to make "git stash
pop/apply" pretend that it was invoked with "--index".
* dk/stash-apply-index:
stash: honor stash.index in apply, pop modes
stash: refactor private config globals
t3905: remove unneeded blank line
t3903: reduce dependencies on previous tests
Declare that "git init" that is not otherwise configured uses
'main' as the initial branch, not 'master', starting Git 3.0.
* pw/3.0-default-initial-branch-to-main:
t0613: stop setting default initial branch
t9902: switch default branch name to main
t4013: switch default branch name to main
breaking-changes: switch default branch to main
The "promisor-remote" capability mechanism has been updated to
allow the "partialCloneFilter" settings and the "token" value to be
communicated from the server side.
* cc/promisor-remote-capability:
promisor-remote: use string_list_split() in mark_remotes_as_accepted()
promisor-remote: allow a client to check fields
promisor-remote: use string_list_split() in filter_promisor_remote()
promisor-remote: refactor how we parse advertised fields
promisor-remote: use string constants for 'name' and 'url' too
promisor-remote: allow a server to advertise more fields
promisor-remote: refactor to get rid of 'struct strvec'
"git send-email" learned to drive "git imap-send" to store already
sent e-mails in an IMAP folder.
* ag/send-email-imap-sent:
send-email: enable copying emails to an IMAP folder without actually sending them
send-email: add ability to send a copy of sent emails to an IMAP folder
"core.commentChar=auto" that attempts to dynamically pick a
suitable comment character is non-workable, as it is too much
trouble to support for little benefit, and is marked as deprecated.
* pw/3.0-commentchar-auto-deprecation:
commit: print advice when core.commentString=auto
config: warn on core.commentString=auto
breaking-changes: deprecate support for core.commentString=auto
"repo info" learns a short-hand option "-z" that is the same as
"--format=nul", and learns to report the objects format used in the
repository.
* lo/repo-info-step-2:
repo: add the field objects.format
repo: add the flag -z as an alias for --format=nul
"git refs exists" that works like "git show-ref --exists" has been
added.
* ms/refs-exists:
t: add test for git refs exists subcommand
t1422: refactor tests to be shareable
t1403: split 'show-ref --exists' tests into a separate file
builtin/refs: add 'exists' subcommand
Documentation for "git add" has been updated.
* je/doc-add:
doc: rephrase the purpose of the staging area
doc: git-add: simplify discussion of ignored files
doc: git-add: clarify intro & add an example
68061e3470 (fast-import: disallow "feature export-marks" by default,
2019-08-29) added the documentation for this option. The second
paragraph is a literal block but it looks like it should just be
a regular paragraph.
Signed-off-by: Kristoffer Haugsbakk <code@khaugsbakk.name>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
From user feedback on this section: 3 users don't know what "tree-ish"
means and 3 users don't know what "pathspec" means. One user also says
that the section is very confusing and that they don't understand what
the "index" is.
From conversations on Mastodon, several users said that their impression
is that "the index" means the same thing as "HEAD". It would be good to
give those users (and other users who do not know what "index" means) a
hint as to its meaning.
Make this section more accessible to users who don't know what the terms
"pathspec", "tree-ish", and "index" mean by using more familiar language,
adding examples, and using simpler sentence structures.
Signed-off-by: Julia Evans <julia@jvns.ca>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
From user feedback: one user mentioned that "When the <tree-ish> (most
often a commit) is not given" is confusing since it starts with a
negative.
Restructuring so that `git checkout main file.txt` and
`git checkout file.txt` are separate items will help us simplify the
sentence structure a lot.
As a bonus, it appears that `-f` actually only applies to one of those
forms, so we can include fewer options, and now the structure of the
DESCRIPTION matches the SYNOPSIS.
Signed-off-by: Julia Evans <julia@jvns.ca>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
From user feedback: several users say they don't understand the use case
for `--detach`. It's probably not realistic to explain the use case for
detached HEAD state here, but we can improve the situation.
Explain how `git checkout --detach` is different from
`git checkout <branch>` instead of copying over the description from
`git checkout <branch>`, since `git checkout <branch>` will be a
familiar command to many readers.
Signed-off-by: Julia Evans <julia@jvns.ca>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
From user feedback: several users reported having trouble understanding
the difference between `-b` and `-B` ("I think it's because my brain
expects it to contrast with `-b`, but instead it starts off explaining
how they're the same").
Also, in `-B`, 2 users can't tell what the branch is reset *to*.
Simplify the sentence structure in the explanations of `-b` and `-B` and
add a little extra information (what `<start-point>` is, what the branch
is reset to).
Splitting up `-b` and `-B` into separate items helps simplify the
sentence structure since there's less "In this case...".
Replace the long "the branch is not reset/created unless "git checkout"
is successful..." with just "will fail", since we should generally
assume that Git will fail operations in a clean way and not leave
operations half-finished, and that cases where it does not fail cleanly
are the exceptions that the documentation should flag.
Signed-off-by: Julia Evans <julia@jvns.ca>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
From user feedback: several users commented that "Local modifications
to the files in the working tree are kept, so that they can be committed
to the <branch>." didn't seem accurate to them, since
`git checkout <branch>` will often fail.
One user also thought that "... and by pointing HEAD at the branch"
was something that _they_ had to do somehow ("How do I point HEAD at
a branch?") rather than a description of what the `git checkout`
operation is doing for them.
Explain when `git checkout <branch>` will fail and clarify that
"pointing HEAD at the branch" is part of what the command does.
6 users commented that the "You could omit <branch>..." section is
extremely confusing. Explain this in a much more direct way.
Signed-off-by: Julia Evans <julia@jvns.ca>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There's no need to use the terms "pathspec" or "tree-ish" in the
ARGUMENT DISAMBIGUATION section, which are terms that (from user
feedback on this page) many users do not understand.
"tree-ish" is actually not accurate here: `git checkout` in this case
takes a commit-ish, not a tree-ish. So we can say "branch or commit"
instead of "tree-ish" which is both more accurate and uses more familiar
terms.
And now that the intro to the man pages mentions that `git checkout` has
"two main modes", it makes sense to refer to this disambiguation section
to understand how Git decides which one to use when there's an overlap
in syntax.
Signed-off-by: Julia Evans <julia@jvns.ca>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
From user feedback: in the first paragraph, 5 users reported not
understanding the terms "pathspec" and 1 user reported not understanding
the term "HEAD". Of the users who said they didn't know what "pathspec"
means, 3 said they couldn't understand what the paragraph was trying to
communicate as a result.
One user also commented that "If no pathspec was given..." makes
`git checkout <branch>` sounds like a special edge case, instead of
being one of the most common ways to use this core Git command.
It looks like the goal of this paragraph is to communicate that `git
checkout` has two different modes: one where you switch branches and one
where you just update your working directory files/index. So say that
directly, and use more familiar language (including examples) to say it.
Signed-off-by: Julia Evans <julia@jvns.ca>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since 1296cbe4b4 (init: document `init.defaultBranch` better,
2020-12-11) "git-init.adoc" has advertised that the default name
of the initial branch may change in the future. The name "main"
is chosen to match the default used by the big Git forge web sites.
The advice printed when init.defaultBranch is not set is updated
to say that the default will change to "main" in Git 3.0. Building
with WITH_BREAKING_CHANGES enabled removes the advice and changes
the default branch name to "main". The code in guess_remote_head()
that looks for "refs/heads/master" is left unchanged as that is only
called when the remote server does not support the symref capability
in the v0 protocol or the symref extension to the ls-refs list in the
v2 protocol. Such an old server is more likely to be using "master"
as the default branch name.
With the exception of the "git-init.adoc" the documentation is left
unchanged. I had hoped to parameterize the name of the default branch
by using an asciidoc attribute. Unfortunately attribute expansion
is inhibited by backticks and we use backticks to mark up ref names
so that idea does not work. As the changes to git-init.adoc show
inserting ifdef's around each instance of the branch name "master"
is cumbersome and makes the documentation sources harder to read.
Apart from "git-init.adoc" there are some other files where "master" is
used as the name of the initial branch rather than as an example of a
branch name such as "user-manual.adoc" and "gitcore-tutorial.adoc". The
name appears a lot in those so updating it with ifdef's is not really
practical. We can update that document in the 3.0 release cycle. The
other documentation where master is used as an example branch name
can be gradually converted over time.
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A new command "git last-modified" has been added to show the closest
ancestor commit that touched each path.
* tc/last-modified:
last-modified: use Bloom filters when available
t/perf: add last-modified perf script
last-modified: new subcommand to show when files were last modified
A previous commit allowed a server to pass additional fields through
the "promisor-remote" protocol capability after the "name" and "url"
fields, specifically the "partialCloneFilter" and "token" fields.
Let's make it possible for a client to check if these fields match
what it expects before accepting a promisor remote.
We allow this by introducing a new "promisor.checkFields"
configuration variable. It should contain a comma or space separated
list of fields that will be checked.
By limiting the protocol to specific well-defined fields, we ensure
both server and client have a shared understanding of field
semantics and usage.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
For now the "promisor-remote" protocol capability can only pass "name"
and "url" information from a server to a client in the form
"name=<remote_name>,url=<remote_url>".
To allow clients to make more informed decisions about which promisor
remotes they accept, let's make it possible to pass more information
by introducing a new "promisor.sendFields" configuration variable.
On the server side, information about a remote `foo` is stored in
configuration variables named `remote.foo.<variable-name>`. To make
it clearer and simpler, we use `field` and `field name` like this:
* `field name` refers to the <variable-name> part of such a
configuration variable, and
* `field` refers to both the `field name` and the value of such a
configuration variable.
The "promisor.sendFields" configuration variable should contain a
comma or space separated list of field names that will be looked up
in the configuration of the remote on the server to find the values
that will be passed to the client.
Only a set of predefined field names are allowed. The only field
names in this set are "partialCloneFilter" and "token". The
"partialCloneFilter" field name specifies the filter definition used
by the promisor remote, and the "token" field name can provide an
authentication credential for accessing it.
For example, if "promisor.sendFields" is set to "partialCloneFilter",
and the server has the "remote.foo.partialCloneFilter" config
variable set to a value, then that value will be passed in the
"partialCloneFilter" field in the form "partialCloneFilter=<value>"
after the "name" and "url" fields.
A following commit will allow the client to use the information to
decide if it accepts the remote or not. For now the client doesn't do
anything with the additional information it receives.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The flag `--show-object-format` from git-rev-parse is used for
retrieving the object storage format. This way, it is used for
querying repository metadata, fitting in the purpose of git-repo-info.
Add a new field `objects.format` to the git-repo-info subcommand
containing that information.
Mentored-by: Karthik Nayak <karthik.188@gmail.com>
Mentored-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Lucas Seiki Oshiro <lucasseikioshiro@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Other Git commands that have nul-terminated output (e.g. git-config,
git-status, git-ls-files) have a flag `-z` for using the null character
as the record separator.
Add the `-z` flag to git-repo-info as an alias for `--format=nul`,
making it consistent with the behavior of the other commands.
Mentored-by: Karthik Nayak <karthik.188@gmail.com>
Mentored-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Lucas Seiki Oshiro <lucasseikioshiro@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The documentation incorrectly referred to the extension without an 's'.
This fixes the typo for clarity.
Signed-off-by: Mikhail Malinouski <m.l.malinouski@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
As part of the ongoing effort to consolidate reference handling,
introduce a new `exists` subcommand. This command provides the same
functionality and exit-code behavior as `git show-ref --exists`, serving
as its modern replacement.
The logic for `show-ref --exists` is minimal. Rather than creating a
shared helper function which would be overkill for ~20 lines of code,
its implementation is intentionally duplicated here. This contrasts with
`git refs list`, where sharing the larger implementation of
`for-each-ref` was necessary.
Documentation for the new subcommand is also added to the `git-refs(1)`
man page.
Mentored-by: Patrick Steinhardt <ps@pks.im>
Mentored-by: shejialuo <shejialuo@gmail.com>
Signed-off-by: Meet Soni <meetsoni3017@gmail.com>
Acked-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a missed backtick to the end of a code segment so that it will be
rendered like preceding examples.
I deeply appreciate the thoroughness of this documentation. I noticed
the formatting discrepancy reading https://git-scm.com/docs/git-config.
Signed-off-by: Kyle E. Mitchell <kyle@kemitchell.com>
Acked-by: Jean-Noël AVILA <avila.jn@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Update the instruction to use of GGG in the MyFirstContribution
document to say that a GitHub PR could be made against `git/git`
instead of `gitgitgadget/git`.
* ds/doc-ggg-pr-fork-clarify:
doc: clarify which remotes can be used with GitGitGadget
