|
|
Repositories contain a file (``.hg/requires``) containing a list of
|
|
|
features/capabilities that are *required* for clients to interface
|
|
|
with the repository. This file has been present in Mercurial since
|
|
|
version 0.9.2 (released December 2006).
|
|
|
|
|
|
One of the first things clients do when opening a repository is read
|
|
|
``.hg/requires`` and verify that all listed requirements are supported,
|
|
|
aborting if not. Requirements are therefore a strong mechanism to
|
|
|
prevent incompatible clients from reading from unknown repository
|
|
|
formats or even corrupting them by writing to them.
|
|
|
|
|
|
Extensions may add requirements. When they do this, clients not running
|
|
|
an extension will be unable to read from repositories.
|
|
|
|
|
|
The following sections describe the requirements defined by the
|
|
|
Mercurial core distribution.
|
|
|
|
|
|
revlogv1
|
|
|
========
|
|
|
|
|
|
When present, revlogs are version 1 (RevlogNG). RevlogNG was introduced
|
|
|
in 2006. The ``revlogv1`` requirement has been enabled by default
|
|
|
since the ``requires`` file was introduced in Mercurial 0.9.2.
|
|
|
|
|
|
If this requirement is not present, version 0 revlogs are assumed.
|
|
|
|
|
|
store
|
|
|
=====
|
|
|
|
|
|
The *store* repository layout should be used.
|
|
|
|
|
|
This requirement has been enabled by default since the ``requires`` file
|
|
|
was introduced in Mercurial 0.9.2.
|
|
|
|
|
|
fncache
|
|
|
=======
|
|
|
|
|
|
The *fncache* repository layout should be used.
|
|
|
|
|
|
The *fncache* layout hash encodes filenames with long paths and
|
|
|
encodes reserved filenames.
|
|
|
|
|
|
This requirement is enabled by default when the *store* requirement is
|
|
|
enabled (which is the default behavior). It was introduced in Mercurial
|
|
|
1.1 (released December 2008).
|
|
|
|
|
|
shared
|
|
|
======
|
|
|
|
|
|
Denotes that the store for a repository is shared from another location
|
|
|
(defined by the ``.hg/sharedpath`` file).
|
|
|
|
|
|
This requirement is set when a repository is created via :hg:`share`.
|
|
|
|
|
|
The requirement was added in Mercurial 1.3 (released July 2009).
|
|
|
|
|
|
relshared
|
|
|
=========
|
|
|
|
|
|
Derivative of ``shared``; the location of the store is relative to the
|
|
|
store of this repository.
|
|
|
|
|
|
This requirement is set when a repository is created via :hg:`share`
|
|
|
using the ``--relative`` option.
|
|
|
|
|
|
The requirement was added in Mercurial 4.2 (released May 2017).
|
|
|
|
|
|
dotencode
|
|
|
=========
|
|
|
|
|
|
The *dotencode* repository layout should be used.
|
|
|
|
|
|
The *dotencode* layout encodes the first period or space in filenames
|
|
|
to prevent issues on OS X and Windows.
|
|
|
|
|
|
This requirement is enabled by default when the *store* requirement
|
|
|
is enabled (which is the default behavior). It was introduced in
|
|
|
Mercurial 1.7 (released November 2010).
|
|
|
|
|
|
parentdelta
|
|
|
===========
|
|
|
|
|
|
Denotes a revlog delta encoding format that was experimental and
|
|
|
replaced by *generaldelta*. It should not be seen in the wild because
|
|
|
it was never enabled by default.
|
|
|
|
|
|
This requirement was added in Mercurial 1.7 and removed in Mercurial
|
|
|
1.9.
|
|
|
|
|
|
generaldelta
|
|
|
============
|
|
|
|
|
|
Revlogs should be created with the *generaldelta* flag enabled. The
|
|
|
generaldelta flag will cause deltas to be encoded against a parent
|
|
|
revision instead of the previous revision in the revlog.
|
|
|
|
|
|
Support for this requirement was added in Mercurial 1.9 (released
|
|
|
July 2011). The requirement was disabled on new repositories by
|
|
|
default until Mercurial 3.7 (released February 2016).
|
|
|
|
|
|
manifestv2
|
|
|
==========
|
|
|
|
|
|
Denotes that version 2 of manifests are being used.
|
|
|
|
|
|
Support for this requirement was added in Mercurial 3.4 (released
|
|
|
May 2015). The new format failed to meet expectations and support
|
|
|
for the format and requirement were removed in Mercurial 4.6
|
|
|
(released May 2018) since the feature never graduated frome experiment
|
|
|
status.
|
|
|
|
|
|
treemanifest
|
|
|
============
|
|
|
|
|
|
Denotes that tree manifests are being used. Tree manifests are
|
|
|
one manifest per directory (as opposed to a single flat manifest).
|
|
|
|
|
|
Support for this requirement was added in Mercurial 3.4 (released
|
|
|
August 2015). The requirement is currently experimental and is
|
|
|
disabled by default.
|
|
|
|
|
|
exp-sparse
|
|
|
==========
|
|
|
|
|
|
The working directory is sparse (only contains a subset of files).
|
|
|
|
|
|
Support for this requirement was added in Mercurial 4.3 (released
|
|
|
August 2017). This requirement and feature are experimental and may
|
|
|
disappear in a future Mercurial release. The requirement will only
|
|
|
be present on repositories that have opted in to a sparse working
|
|
|
directory.
|
|
|
|
|
|
bookmarksinstore
|
|
|
================
|
|
|
|
|
|
Bookmarks are stored in ``.hg/store/`` instead of directly in ``.hg/``
|
|
|
where they used to be stored. The active bookmark is still stored
|
|
|
directly in ``.hg/``. This makes them always shared by ``hg share``,
|
|
|
whether or not ``-B`` was passed.
|
|
|
|
|
|
Support for this requirement was added in Mercurial 5.1 (released
|
|
|
August 2019). The requirement will only be present on repositories
|
|
|
that have opted in to this format (by having
|
|
|
``format.bookmarks-in-store=true`` set when they were created).
|
|
|
|
|
|
persistent-nodemap
|
|
|
==================
|
|
|
|
|
|
The `nodemap` index (mapping nodeid to local revision number) is persisted on
|
|
|
disk. This provides speed benefit (if the associated native code is used). The
|
|
|
persistent nodemap is only used for two revlogs: the changelog and the
|
|
|
manifestlog.
|
|
|
|
|
|
Support for this requirement was added in Mercurial 5.5 (released August 2020).
|
|
|
Note that as of 5.5, only installations compiled with the Rust extension will
|
|
|
benefit from a speedup. The other installations will do the necessary work to
|
|
|
keep the index up to date, but will suffer a slowdown.
|
|
|
|
|
|
share-safe
|
|
|
==========
|
|
|
|
|
|
Represents that the repository can be shared safely. Requirements and config of
|
|
|
the source repository will be shared.
|
|
|
Requirements are stored in ``.hg/store`` instead of directly in ``.hg/`` where
|
|
|
they used to be stored. Some working copy related requirements are still stored
|
|
|
in ``.hg/``.
|
|
|
Shares read the ``.hg/hgrc`` of the source repository.
|
|
|
|
|
|
Support for this requirement was added in Mercurial 5.7 (released
|
|
|
February 2021). The requirement will only be present on repositories that have
|
|
|
opted in to this format (by having ``format.use-share-safe=true`` set when
|
|
|
they were created).
|
|
|
|
