~bzr-pqm/bzr/bzr.dev

# Copyright (C) 2006, 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

"""MutableTree object.

See MutableTree for more details.

"""

from bzrlib import (

    errors,

    osutils,

    tree,

    )

from bzrlib.decorators import needs_read_lock, needs_write_lock

from bzrlib.osutils import splitpath

from bzrlib.symbol_versioning import DEPRECATED_PARAMETER

def needs_tree_write_lock(unbound):

    """Decorate unbound to take out and release a tree_write lock."""

    def tree_write_locked(self, *args, **kwargs):

        self.lock_tree_write()

        try:

            return unbound(self, *args, **kwargs)

        finally:

            self.unlock()

    tree_write_locked.__doc__ = unbound.__doc__

    tree_write_locked.__name__ = unbound.__name__

    return tree_write_locked

class MutableTree(tree.Tree):

    """A MutableTree is a specialisation of Tree which is able to be mutated.

    Generally speaking these mutations are only possible within a lock_write

    context, and will revert if the lock is broken abnormally - but this cannot

    be guaranteed - depending on the exact implementation of the mutable state.

    The most common form of Mutable Tree is WorkingTree, see bzrlib.workingtree.

    For tests we also have MemoryTree which is a MutableTree whose contents are

    entirely in memory.

    For now, we are not treating MutableTree as an interface to provide

    conformance tests for - rather we are testing MemoryTree specifically, and 

    interface testing implementations of WorkingTree.

    A mutable tree always has an associated Branch and BzrDir object - the

    branch and bzrdir attributes.

    """

    @needs_tree_write_lock

    def add(self, files, ids=None, kinds=None):

        """Add paths to the set of versioned paths.

        Note that the command line normally calls smart_add instead,

        which can automatically recurse.

        This adds the files to the inventory, so that they will be

        recorded by the next commit.

        :param files: List of paths to add, relative to the base of the tree.

        :param ids: If set, use these instead of automatically generated ids.

            Must be the same length as the list of files, but may

            contain None for ids that are to be autogenerated.

        :param kinds: Optional parameter to specify the kinds to be used for

            each file.

        TODO: Perhaps callback with the ids and paths as they're added.

        """

        if isinstance(files, basestring):

            assert(ids is None or isinstance(ids, basestring))

            assert(kinds is None or isinstance(kinds, basestring))

            files = [files]

            if ids is not None:

                ids = [ids]

            if kinds is not None:

                kinds = [kinds]

        files = [path.strip('/') for path in files]

        if ids is None:

            ids = [None] * len(files)

        else:

            assert(len(ids) == len(files))

            ids = [osutils.safe_file_id(file_id) for file_id in ids]

        if kinds is None:

            kinds = [None] * len(files)

        else:

            assert(len(kinds) == len(files))

        for f in files:

            # generic constraint checks:

            if self.is_control_filename(f):

                raise errors.ForbiddenControlFileError(filename=f)

            fp = splitpath(f)

        # fill out file kinds for all files [not needed when we stop 

        # caring about the instantaneous file kind within a uncommmitted tree

        #

        self._gather_kinds(files, kinds)

        self._add(files, ids, kinds)

    def add_reference(self, sub_tree):

        """Add a TreeReference to the tree, pointing at sub_tree"""

        raise errors.UnsupportedOperation(self.add_reference, self)

    def _add_reference(self, sub_tree):

        """Standard add_reference implementation, for use by subclasses"""

        try:

            sub_tree_path = self.relpath(sub_tree.basedir)

        except errors.PathNotChild:

            raise errors.BadReferenceTarget(self, sub_tree,

                                            'Target not inside tree.')

        sub_tree_id = sub_tree.get_root_id()

        if sub_tree_id == self.get_root_id():

            raise errors.BadReferenceTarget(self, sub_tree,

                                     'Trees have the same root id.')

        if sub_tree_id in self.inventory:

            raise errors.BadReferenceTarget(self, sub_tree,

                                            'Root id already present in tree')

        self._add([sub_tree_path], [sub_tree_id], ['tree-reference'])

    def _add(self, files, ids, kinds):

        """Helper function for add - updates the inventory.

        :param files: sequence of pathnames, relative to the tree root

        :param ids: sequence of suggested ids for the files (may be None)

        :param kinds: sequence of  inventory kinds of the files (i.e. may

            contain "tree-reference")

        """

        raise NotImplementedError(self._add)

    @needs_write_lock

    def commit(self, message=None, revprops=None, *args,

               **kwargs):

        # avoid circular imports

        from bzrlib import commit

        if revprops is None:

            revprops = {}

        if not 'branch-nick' in revprops:

            revprops['branch-nick'] = self.branch.nick

        # args for wt.commit start at message from the Commit.commit method,

        # but with branch a kwarg now, passing in args as is results in the

        #message being used for the branch

        args = (DEPRECATED_PARAMETER, message, ) + args

        committed_id = commit.Commit().commit(working_tree=self,

            revprops=revprops, *args, **kwargs)

        return committed_id

    def _gather_kinds(self, files, kinds):

        """Helper function for add - sets the entries of kinds."""

        raise NotImplementedError(self._gather_kinds)

    @needs_read_lock

    def last_revision(self):

        """Return the revision id of the last commit performed in this tree.

        In early tree formats the result of last_revision is the same as the

        branch last_revision, but that is no longer the case for modern tree

        formats.

        last_revision returns the left most parent id, or None if there are no

        parents.

        last_revision was deprecated as of 0.11. Please use get_parent_ids

        instead.

        """

        raise NotImplementedError(self.last_revision)

    def lock_tree_write(self):

        """Lock the working tree for write, and the branch for read.

        This is useful for operations which only need to mutate the working

        tree. Taking out branch write locks is a relatively expensive process

        and may fail if the branch is on read only media. So branch write locks

        should only be taken out when we are modifying branch data - such as in

        operations like commit, pull, uncommit and update.

        """

        raise NotImplementedError(self.lock_tree_write)

    def lock_write(self):

        """Lock the tree and its branch. This allows mutating calls to be made.

        Some mutating methods will take out implicit write locks, but in 

        general you should always obtain a write lock before calling mutating

        methods on a tree.

        """

        raise NotImplementedError(self.lock_write)

    @needs_write_lock

    def mkdir(self, path, file_id=None):

        """Create a directory in the tree. if file_id is None, one is assigned.

        :param path: A unicode file path.

        :param file_id: An optional file-id.

        :return: the file id of the new directory.

        """

        raise NotImplementedError(self.mkdir)

    def set_parent_trees(self, parents_list, allow_leftmost_as_ghost=False):

        """Set the parents of the working tree.

        :param parents_list: A list of (revision_id, tree) tuples. 

            If tree is None, then that element is treated as an unreachable

            parent tree - i.e. a ghost.

        """

        raise NotImplementedError(self.set_parent_trees)