view mercurial/help/phases.txt @ 35616:706aa203b396

fileset: add a lightweight file filtering language

This patch was inspired by one that Jun Wu authored for the fb-experimental
repo, to avoid using matcher for efficiency[1].  We want a way to specify what
files will be converted to LFS at commit time.  And per discussion, we also want
to specify what files to skip, text diff, or merge in another config option.
The current `lfs.threshold` config option could not satisfy complex needs.  I'm
putting it in a core package because Augie floated the idea of also using it for
narrow and sparse.

Yuya suggested farming out to fileset.parse(), which added support for more
symbols.  The only fileset element not supported here is 'negate'.  (List isn't
supported by filesets either.)  I also changed the 'always' token to the 'all()'
predicate for consistency, and introduced 'none()' to improve readability in a
future tracked file based config.  The extension operator was changed from '.'
to '**', to match how recursive path globs are specified.  Finally, I changed
the path matcher from '/' to 'path:' at Yuya's suggestion, for consistency with
matcher.  Unfortunately, ':' is currently reserved in filesets, so this has to
be quoted to be processed as a string instead of a symbol[2].  We should
probably revisit that, because it's seriously ugly.  But it's only used by an
experimental extension, and I think using a file based config for LFS may drive
some more tweaks, so I'm settling for this for now.

I reserved all of the glob characters in fileset except '.' and '_' for the
extension test because those are likely valid extension characters.

Sample filter settings:

  all()                        # everything
  size(">20MB")                # larger than 20MB
  !**.txt                      # except for .txt files
  **.zip | **.tar.gz | **.7z   # some types of compressed files
  "path:bin"                   # files under "bin" in the project root

[1] https://www.mercurial-scm.org/pipermail/mercurial-devel/2017-December/109387.html
[2] https://www.mercurial-scm.org/pipermail/mercurial-devel/2018-January/109729.html

What are phases?
================

Phases are a system for tracking which changesets have been or should
be shared. This helps prevent common mistakes when modifying history
(for instance, with the mq or rebase extensions).

Each changeset in a repository is in one of the following phases:

 - public : changeset is visible on a public server
 - draft : changeset is not yet published
 - secret : changeset should not be pushed, pulled, or cloned

These phases are ordered (public < draft < secret) and no changeset
can be in a lower phase than its ancestors. For instance, if a
changeset is public, all its ancestors are also public. Lastly,
changeset phases should only be changed towards the public phase.

How are phases managed?
=======================

For the most part, phases should work transparently. By default, a
changeset is created in the draft phase and is moved into the public
phase when it is pushed to another repository.

Once changesets become public, extensions like mq and rebase will
refuse to operate on them to prevent creating duplicate changesets.
Phases can also be manually manipulated with the :hg:`phase` command
if needed. See :hg:`help -v phase` for examples.

To make your commits secret by default, put this in your
configuration file::

  [phases]
  new-commit = secret

Phases and servers
==================

Normally, all servers are ``publishing`` by default. This means::

 - all draft changesets that are pulled or cloned appear in phase
 public on the client

 - all draft changesets that are pushed appear as public on both
 client and server

 - secret changesets are neither pushed, pulled, or cloned

.. note::

  Pulling a draft changeset from a publishing server does not mark it
  as public on the server side due to the read-only nature of pull.

Sometimes it may be desirable to push and pull changesets in the draft
phase to share unfinished work. This can be done by setting a
repository to disable publishing in its configuration file::

  [phases]
  publish = False

See :hg:`help config` for more information on configuration files.

.. note::

  Servers running older versions of Mercurial are treated as
  publishing.

.. note::

   Changesets in secret phase are not exchanged with the server. This
   applies to their content: file names, file contents, and changeset
   metadata. For technical reasons, the identifier (e.g. d825e4025e39)
   of the secret changeset may be communicated to the server.


Examples
========

 - list changesets in draft or secret phase::

     hg log -r "not public()"

 - change all secret changesets to draft::

     hg phase --draft "secret()"

 - forcibly move the current changeset and descendants from public to draft::

     hg phase --force --draft .

 - show a list of changeset revisions and each corresponding phase::

     hg log --template "{rev} {phase}\n"

 - resynchronize draft changesets relative to a remote repository::

     hg phase -fd "outgoing(URL)"

See :hg:`help phase` for more information on manually manipulating phases.