/brz/remove-bazaar

# Copyright (C) 2006, 2008, 2009, 2010 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

"""TreeBuilder helper class.

TreeBuilders are used to build trees of various shapes or properties. This

can be extremely useful in testing for instance.

"""

from . import errors

class AlreadyBuilding(errors.BzrError):

    _fmt = "The tree builder is already building a tree."

class NotBuilding(errors.BzrError):

    _fmt = "Not currently building a tree."

class TreeBuilder(object):

    """A TreeBuilder allows the creation of specific content in one tree at a

    time.

    """

    def __init__(self):

        """Construct a TreeBuilder."""

        self._tree = None

        self._root_done = False

    def build(self, recipe):

        """Build recipe into the current tree.

        :param recipe: A sequence of paths. For each path, the corresponding

            path in the current tree is created and added. If the path ends in

            '/' then a directory is added, otherwise a regular file is added.

        """

        self._ensure_building()

        if not self._root_done:

            self._tree.add('', b'root-id', 'directory')

            self._root_done = True

        for name in recipe:

            if name.endswith('/'):

                self._tree.mkdir(name[:-1])

            else:

                end = b'\n'

                content = b"contents of %s%s" % (name.encode('utf-8'), end)

                self._tree.add(name, None, 'file')

                self._tree.put_file_bytes_non_atomic(name, content)

    def _ensure_building(self):

        """Raise NotBuilding if there is no current tree being built."""

        if self._tree is None:

            raise NotBuilding

    def finish_tree(self):

        """Finish building the current tree."""

        self._ensure_building()

        tree = self._tree

        self._tree = None

        tree.unlock()

    def start_tree(self, tree):

        """Start building on tree.

        :param tree: A tree to start building on. It must provide the

            MutableTree interface.

        """

        if self._tree is not None:

            raise AlreadyBuilding

        self._tree = tree

        self._tree.lock_tree_write()