~bzr-pqm/bzr/bzr.dev

# Copyright (C) 2007 Canonical Ltd

#

# 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

"""Utility for create branches with particular contents."""

from bzrlib import bzrdir, errors, memorytree

class BranchBuilder(object):

    """A BranchBuilder aids creating Branches with particular shapes.

    The expected way to use BranchBuilder is to construct a

    BranchBuilder on the transport you want your branch on, and then call

    appropriate build_ methods on it to get the shape of history you want.

    For instance:

      builder = BranchBuilder(self.get_transport().clone('relpath'))

      builder.build_commit()

      builder.build_commit()

      builder.build_commit()

      branch = builder.get_branch()

    """

    def __init__(self, transport, format=None):

        """Construct a BranchBuilder on transport.

        :param transport: The transport the branch should be created on.

            If the path of the transport does not exist but its parent does

            it will be created.

        :param format: The name of a format in the bzrdir format registry

            for the branch to be built.

        """

        if not transport.has('.'):

            transport.mkdir('.')

        if format is None:

            format = 'default'

        self._branch = bzrdir.BzrDir.create_branch_convenience(transport.base,

            format=bzrdir.format_registry.make_bzrdir(format))

    def build_commit(self):

        """Build a commit on the branch."""

        tree = memorytree.MemoryTree.create_on_branch(self._branch)

        tree.lock_write()

        try:

            tree.add('')

            return tree.commit('commit %d' % (self._branch.revno() + 1))

        finally:

            tree.unlock()

    def get_branch(self):

        """Return the branch created by the builder."""

        return self._branch