~abentley/bzrtools/bzrtools.dev

# Copyright (C) 2006 Canonical Limited.

# Authors: David Allouche <david@allouche.net>

#          Aaron Bentley <aaron.bentley@utoronto.ca>

#

#    This program is free software; you can redistribute it and/or modify

#    it under the terms of the GNU General Public License as published by

#    the Free Software Foundation; either version 2 of the License, or

#    (at your option) any later version.

#

#    This program is distributed in the hope that it will be useful,

#    but WITHOUT ANY WARRANTY; without even the implied warranty of

#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

#    GNU General Public License for more details.

#

#    You should have received a copy of the GNU General Public License

#    along with this program; if not, write to the Free Software

#    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

from bzrlib.errors import BzrCommandError

from bzrlib.commands import Command, register_command

from bzrlib.branch import Branch, BranchFormat

from bzrlib.bzrdir import BzrDir, BzrDirFormat

from bzrlib.transport import get_transport

from bzrlib.builtins import cmd_update

from bzrlib.trace import note

from bzrlib.workingtree import WorkingTree

class cmd_switch(Command):

    """Set the branch of a lightweight checkout and update.  <BZRTOOLS>"""

    takes_args = ['to_location']

    def run(self, to_location):

        to_branch = Branch.open(to_location)

        tree_location = '.'

        self._switch(tree_location, to_branch)

        # need to re-open tree to get the new branch

        tree = WorkingTree.open_containing(tree_location)[0]

        self._update(tree)

    def _switch(self, tree_location, to_branch):

        tree = WorkingTree.open_containing(tree_location)[0]

        tree.lock_write()

        try:

            self._check_switch_branch_format(tree_location)

            self.set_branch_location(tree.bzrdir, to_branch.base)

            note('Switched to branch: %s' % (to_branch.base,))

        finally:

            tree.unlock()

    def _update(self, tree):

        tree.lock_write()

        try:

            if tree.last_revision() == tree.branch.last_revision():

                assert tree.branch.get_master_branch() is None, (

                    "switch tried to update a fat checkout")

                note("Tree is up to date.")

                return

            tree.update()

            note('Updated to revision %d' %

                 (tree.branch.revision_id_to_revno(tree.last_revision()),))

        finally:

            tree.unlock()

    def _check_switch_branch_format(self, url):

        transport = get_transport(url)

        format = BzrDirFormat.find_format(transport)

        format_string = format.get_format_string()

        if not format_string.startswith("Bazaar-NG meta directory, "):

            raise BzrCommandError(

                'The switch command can only be used on a light checkout.\n'

                'Expected metadir, found %s at %s' % (

                format_string.strip(), transport.base))

        control = BzrDir.open_containing_from_transport(transport)[0]

        branch_format = BranchFormat.find_format(control)

        format_string = branch_format.get_format_string()

        if not format_string.startswith("Bazaar-NG Branch Reference Format "):

            raise BzrCommandError(

                'The switch command can only be used on a light checkout.\n'

                'Expected branch reference, found %s at %s' % (

                format_string.strip(), transport.base))

        if not format_string == "Bazaar-NG Branch Reference Format 1\n":

            raise BzrCommandError(

                'Unsupported: %r' % (format_string.strip(),))        

    def set_branch_location(self, control, location):

        """Set location value of a branch reference.

        The branch living in the control (BzrDir) object must be locked for

        writing.

        :param control: BzrDir containing the branch reference

        :param location: value to write to the branch reference location.

        """

        branch_format = BranchFormat.find_format(control)

        transport = control.get_branch_transport(None)

        branch = branch_format.open(control)

        location = transport.put('location', location)