view hgext/children.py @ 31994:b36318e6d2ef

track-tags: introduce first bits of tags tracking during transaction

This changeset introduces detection of tags changes during transaction. When
this happens a 'tag_moved=1' argument is set for hooks, similar to what we do
for bookmarks and phases.

This code is disabled by default as there are still various performance
concerns.  Some require a smarter use of our existing tag caches and some other
require rework around the transaction logic to skip execution when unneeded.
These performance improvements have been delayed, I would like to be able to
experiment and stabilize the feature behavior first.

Later changesets will push the concept further and provide a way for hooks to
know what are the actual changes introduced by the transaction. Similar work
is needed for the other families of changes (bookmark, phase, obsolescence,
etc). Upgrade of the transaction logic will likely be performed at the same
time.

The current code can report some false positive when .hgtags file changes but
resulting tags are unchanged. This will be fixed in the next changeset.

For testing, we simply globally enable a hook in the tag test as all the
possible tag update cases should exist there. A couple of them show the false
positive mentioned above.

See in code documentation for more details.

# Mercurial extension to provide the 'hg children' command
#
# Copyright 2007 by Intevation GmbH <[e-mail]>
#
# Author(s):
# Thomas Arendsen Hein <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

'''command to display child changesets (DEPRECATED)

This extension is deprecated. You should use :hg:`log -r
"children(REV)"` instead.
'''

from __future__ import absolute_import

from mercurial.i18n import _
from mercurial import (
    cmdutil,
    commands,
)

templateopts = commands.templateopts

cmdtable = {}
command = cmdutil.command(cmdtable)
# Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for
# extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
# be specifying the version(s) of Mercurial they are tested with, or
# leave the attribute unspecified.
testedwith = 'ships-with-hg-core'

@command('children',
    [('r', 'rev', '',
     _('show children of the specified revision'), _('REV')),
    ] + templateopts,
    _('hg children [-r REV] [FILE]'),
    inferrepo=True)
def children(ui, repo, file_=None, **opts):
    """show the children of the given or working directory revision

    Print the children of the working directory's revisions. If a
    revision is given via -r/--rev, the children of that revision will
    be printed. If a file argument is given, revision in which the
    file was last changed (after the working directory revision or the
    argument to --rev if given) is printed.

    Please use :hg:`log` instead::

        hg children => hg log -r "children()"
        hg children -r REV => hg log -r "children(REV)"

    See :hg:`help log` and :hg:`help revsets.children`.

    """
    rev = opts.get('rev')
    if file_:
        fctx = repo.filectx(file_, changeid=rev)
        childctxs = [fcctx.changectx() for fcctx in fctx.children()]
    else:
        ctx = repo[rev]
        childctxs = ctx.children()

    displayer = cmdutil.show_changeset(ui, repo, opts)
    for cctx in childctxs:
        displayer.show(cctx)
    displayer.close()