Mercurial > hg
view mercurial/help/subrepos.txt @ 26755:bb0b955d050d
streamclone: support for producing and consuming stream clone bundles
Up to this point, stream clones only existed as a dynamically generated
data format produced and consumed during streaming clones. In order to
support this efficient cloning format with the clone bundles feature, we
need a more formal, on disk representation of the streaming clone data.
This patch introduces a new "bundle" type for streaming clones. Unlike
existing bundles, it does not contain changegroup data. It does,
however, share the same concepts like the 4 byte header which identifies
the type of data that follows and the 2 byte abbreviation for
compression types (of which only "UN" is currently supported).
The new bundle format is essentially the existing stream clone version 1
data format with some headers at the beginning.
Content negotiation at stream clone request time checked for repository
format/requirements compatibility before initiating a stream clone. We
can't do active content negotiation when using clone bundles. So, we put
this set of requirements inside the payload so consumers have a built-in
mechanism for checking compatibility before reading and applying lots of
data. Of course, we will also advertise this requirements set in clone
bundles. But that's for another patch.
We currently don't have a mechanism to produce and consume this new
bundle format. This will be implemented in upcoming patches.
It's worth noting that if a legacy client attempts to `hg unbundle` a
stream clone bundle (with the "HGS1" header), it will abort with:
"unknown bundle version S1," which seems appropriate.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Sat, 17 Oct 2015 11:14:52 -0700 |
parents | 63a57a2727b6 |
children | 2406dbba49bd |
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Subrepositories let you nest external repositories or projects into a parent Mercurial repository, and make commands operate on them as a group. Mercurial currently supports Mercurial, Git, and Subversion subrepositories. Subrepositories are made of three components: 1. Nested repository checkouts. They can appear anywhere in the parent working directory. 2. Nested repository references. They are defined in ``.hgsub``, which should be placed in the root of working directory, and tell where the subrepository checkouts come from. Mercurial subrepositories are referenced like:: path/to/nested = https://example.com/nested/repo/path Git and Subversion subrepos are also supported:: path/to/nested = [git]git://example.com/nested/repo/path path/to/nested = [svn]https://example.com/nested/trunk/path where ``path/to/nested`` is the checkout location relatively to the parent Mercurial root, and ``https://example.com/nested/repo/path`` is the source repository path. The source can also reference a filesystem path. Note that ``.hgsub`` does not exist by default in Mercurial repositories, you have to create and add it to the parent repository before using subrepositories. 3. Nested repository states. They are defined in ``.hgsubstate``, which is placed in the root of working directory, and capture whatever information is required to restore the subrepositories to the state they were committed in a parent repository changeset. Mercurial automatically record the nested repositories states when committing in the parent repository. .. note:: The ``.hgsubstate`` file should not be edited manually. Adding a Subrepository ====================== If ``.hgsub`` does not exist, create it and add it to the parent repository. Clone or checkout the external projects where you want it to live in the parent repository. Edit ``.hgsub`` and add the subrepository entry as described above. At this point, the subrepository is tracked and the next commit will record its state in ``.hgsubstate`` and bind it to the committed changeset. Synchronizing a Subrepository ============================= Subrepos do not automatically track the latest changeset of their sources. Instead, they are updated to the changeset that corresponds with the changeset checked out in the top-level changeset. This is so developers always get a consistent set of compatible code and libraries when they update. Thus, updating subrepos is a manual process. Simply check out target subrepo at the desired revision, test in the top-level repo, then commit in the parent repository to record the new combination. Deleting a Subrepository ======================== To remove a subrepository from the parent repository, delete its reference from ``.hgsub``, then remove its files. Interaction with Mercurial Commands =================================== :add: add does not recurse in subrepos unless -S/--subrepos is specified. However, if you specify the full path of a file in a subrepo, it will be added even without -S/--subrepos specified. Subversion subrepositories are currently silently ignored. :addremove: addremove does not recurse into subrepos unless -S/--subrepos is specified. However, if you specify the full path of a directory in a subrepo, addremove will be performed on it even without -S/--subrepos being specified. Git and Subversion subrepositories will print a warning and continue. :archive: archive does not recurse in subrepositories unless -S/--subrepos is specified. :cat: cat currently only handles exact file matches in subrepos. Subversion subrepositories are currently ignored. :commit: commit creates a consistent snapshot of the state of the entire project and its subrepositories. If any subrepositories have been modified, Mercurial will abort. Mercurial can be made to instead commit all modified subrepositories by specifying -S/--subrepos, or setting "ui.commitsubrepos=True" in a configuration file (see :hg:`help config`). After there are no longer any modified subrepositories, it records their state and finally commits it in the parent repository. The --addremove option also honors the -S/--subrepos option. However, Git and Subversion subrepositories will print a warning and abort. :diff: diff does not recurse in subrepos unless -S/--subrepos is specified. Changes are displayed as usual, on the subrepositories elements. Subversion subrepositories are currently silently ignored. :files: files does not recurse into subrepos unless -S/--subrepos is specified. However, if you specify the full path of a file or directory in a subrepo, it will be displayed even without -S/--subrepos being specified. Git and Subversion subrepositories are currently silently ignored. :forget: forget currently only handles exact file matches in subrepos. Git and Subversion subrepositories are currently silently ignored. :incoming: incoming does not recurse in subrepos unless -S/--subrepos is specified. Git and Subversion subrepositories are currently silently ignored. :outgoing: outgoing does not recurse in subrepos unless -S/--subrepos is specified. Git and Subversion subrepositories are currently silently ignored. :pull: pull is not recursive since it is not clear what to pull prior to running :hg:`update`. Listing and retrieving all subrepositories changes referenced by the parent repository pulled changesets is expensive at best, impossible in the Subversion case. :push: Mercurial will automatically push all subrepositories first when the parent repository is being pushed. This ensures new subrepository changes are available when referenced by top-level repositories. Push is a no-op for Subversion subrepositories. :status: status does not recurse into subrepositories unless -S/--subrepos is specified. Subrepository changes are displayed as regular Mercurial changes on the subrepository elements. Subversion subrepositories are currently silently ignored. :remove: remove does not recurse into subrepositories unless -S/--subrepos is specified. However, if you specify a file or directory path in a subrepo, it will be removed even without -S/--subrepos. Git and Subversion subrepositories are currently silently ignored. :update: update restores the subrepos in the state they were originally committed in target changeset. If the recorded changeset is not available in the current subrepository, Mercurial will pull it in first before updating. This means that updating can require network access when using subrepositories. Remapping Subrepositories Sources ================================= A subrepository source location may change during a project life, invalidating references stored in the parent repository history. To fix this, rewriting rules can be defined in parent repository ``hgrc`` file or in Mercurial configuration. See the ``[subpaths]`` section in hgrc(5) for more details.