The "reference-transaction" hook is invoked multiple times during a ref
transaction. Each invocation corresponds to a different phase:
- The "prepared" phase indicates that references have been locked.
- The "committed" phase indicates that all updates have been written to disk.
- The "aborted" phase indicates that the transaction has been aborted and that
all changes have been rolled back.
This hook can be used to learn about the updates that Git wants to perform.
For example, forges use it to coordinate reference updates across multiple
nodes.
However, the phases are insufficient for some specific use cases. The earliest
observable phase in the "reference-transaction" hook is "prepared", at which
point Git has already taken exclusive locks on every affected reference. This
makes it suitable for last-chance validation, but not for serialization. So by
the time a hook sees the "prepared" phase, it has no way to defer locking, and
thus it cannot rearrange multiple concurrent ref transactions relative to one
another.
Introduce a new "preparing" phase that runs before the "prepared" phase, that
is before Git acquires any reference lock on disk. This gives callers a
well-defined window to perform validation, enable higher-level ordering of
concurrent transactions, or reject the transaction entirely, all without
interfering with the locking state.
This change is strictly speaking not backwards compatible. Existing hook
scripts that do not know how to handle unknown phases may treat 'preparing'
as an error and return non-zero. But the hook is considered to expose
internal implementation details of how Git works, and as such we have
been a bit more lenient with changing its exact semantics, like for example
in a8ae923f85 (refs: support symrefs in 'reference-transaction' hook, 2024-05-07).
An alternative would be to introduce a "reference-transaction-v2" hook that
knows about the new phase. This feels like a rather heavy-weight option though,
and was thus discarded.
Helped-by: Patrick Steinhardt <ps@pks.im>
Helped-by: Justin Tobler <jltobler@gmail.com>
Helped-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Eric Ju <eric.peijian@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Join two paragraphs that start with the standard “The default <hook>,
when enabled” into one and put it at the end of the “pre-commit”
section.
The trailing whitespace paragraph was added in the first commit for the
doc, in 6d35cc76 (Document hooks., 2005-09-02). Then 3e14dd2c (mention
use of "hooks.allownonascii" in "man githooks", 2019-02-20) updated the
“pre-commit” section to mention the non-ASCII check that was added in
d00e364d.[1] But this paragraph was added one-past the original
“default” paragraph, after the env. variable paragraph, and starts
exactly the same. That causes the flow of this section to feel
off (paragraphs in order):
1. Invoked by <cmd> and what parameters it takes
2. The default 'pre-commit' hook catches introduction of trailing
whitespace
3. `GIT_EDITOR=:`
4. The default pre-commit' hook catches introduction of non-ASCII
filenames
Let’s instead join these two paragrahs and explain the whole behavior of
the default script.
† 1: Extend sample pre-commit hook to check for non ascii filenames,
2009-05-19
Signed-off-by: Kristoffer Haugsbakk <code@khaugsbakk.name>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We presently use the ".txt" extension for our AsciiDoc files. While not
wrong, most editors do not associate this extension with AsciiDoc,
meaning that contributors don't get automatic editor functionality that
could be useful, such as syntax highlighting and prose linting.
It is much more common to use the ".adoc" extension for AsciiDoc files,
since this helps editors automatically detect files and also allows
various forges to provide rich (HTML-like) rendering. Let's do that
here, renaming all of the files and updating the includes where
relevant. Adjust the various build scripts and makefiles to use the new
extension as well.
Note that this should not result in any user-visible changes to the
documentation.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
