~bzr-pqm/bzr/bzr.dev

# Copyright (C) 2007-2011 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

"""WorkingTree3 format and implementation.

"""

from bzrlib import (

    bzrdir,

    errors,

    inventory,

    revision as _mod_revision,

    transform,

    )

from bzrlib.decorators import (

    needs_read_lock,

    )

from bzrlib.lockable_files import LockableFiles

from bzrlib.lockdir import LockDir

from bzrlib.transport.local import LocalTransport

from bzrlib.workingtree import (

    InventoryWorkingTree,

    WorkingTreeFormat,

    )

class WorkingTree3(InventoryWorkingTree):

    """This is the Format 3 working tree.

    This differs from the base WorkingTree by:

     - having its own file lock

     - having its own last-revision property.

    This is new in bzr 0.8

    """

    @needs_read_lock

    def _last_revision(self):

        """See Mutable.last_revision."""

        try:

            return self._transport.get_bytes('last-revision')

        except errors.NoSuchFile:

            return _mod_revision.NULL_REVISION

    def _change_last_revision(self, revision_id):

        """See WorkingTree._change_last_revision."""

        if revision_id is None or revision_id == _mod_revision.NULL_REVISION:

            try:

                self._transport.delete('last-revision')

            except errors.NoSuchFile:

                pass

            return False

        else:

            self._transport.put_bytes('last-revision', revision_id,

                mode=self.bzrdir._get_file_mode())

            return True

    def _get_check_refs(self):

        """Return the references needed to perform a check of this tree."""

        return [('trees', self.last_revision())]

    def unlock(self):

        # do non-implementation specific cleanup

        self._cleanup()

        if self._control_files._lock_count == 1:

            # _inventory_is_modified is always False during a read lock.

            if self._inventory_is_modified:

                self.flush()

            self._write_hashcache_if_dirty()

        # reverse order of locking.

        try:

            return self._control_files.unlock()

        finally:

            self.branch.unlock()

class WorkingTreeFormat3(WorkingTreeFormat):

    """The second working tree format updated to record a format marker.

    This format:

        - exists within a metadir controlling .bzr

        - includes an explicit version marker for the workingtree control

          files, separate from the BzrDir format

        - modifies the hash cache format

        - is new in bzr 0.8

        - uses a LockDir to guard access for writes.

    """

    upgrade_recommended = True

    missing_parent_conflicts = True

    def get_format_string(self):

        """See WorkingTreeFormat.get_format_string()."""

        return "Bazaar-NG Working Tree format 3"

    def get_format_description(self):

        """See WorkingTreeFormat.get_format_description()."""

        return "Working tree format 3"

    _tree_class = WorkingTree3

    def __get_matchingbzrdir(self):

        return bzrdir.BzrDirMetaFormat1()

    _matchingbzrdir = property(__get_matchingbzrdir)

    def _open_control_files(self, a_bzrdir):

        transport = a_bzrdir.get_workingtree_transport(None)

        return LockableFiles(transport, 'lock', LockDir)

    def initialize(self, a_bzrdir, revision_id=None, from_branch=None,

                   accelerator_tree=None, hardlink=False):

        """See WorkingTreeFormat.initialize().

        :param revision_id: if supplied, create a working tree at a different

            revision than the branch is at.

        :param accelerator_tree: A tree which can be used for retrieving file

            contents more quickly than the revision tree, i.e. a workingtree.

            The revision tree will be used for cases where accelerator_tree's

            content is different.

        :param hardlink: If true, hard-link files from accelerator_tree,

            where possible.

        """

        if not isinstance(a_bzrdir.transport, LocalTransport):

            raise errors.NotLocalUrl(a_bzrdir.transport.base)

        transport = a_bzrdir.get_workingtree_transport(self)

        control_files = self._open_control_files(a_bzrdir)

        control_files.create_lock()

        control_files.lock_write()

        transport.put_bytes('format', self.get_format_string(),

            mode=a_bzrdir._get_file_mode())

        if from_branch is not None:

            branch = from_branch

        else:

            branch = a_bzrdir.open_branch()

        if revision_id is None:

            revision_id = _mod_revision.ensure_null(branch.last_revision())

        # WorkingTree3 can handle an inventory which has a unique root id.

        # as of bzr 0.12. However, bzr 0.11 and earlier fail to handle

        # those trees. And because there isn't a format bump inbetween, we

        # are maintaining compatibility with older clients.

        # inv = Inventory(root_id=gen_root_id())

        inv = self._initial_inventory()

        wt = self._tree_class(a_bzrdir.root_transport.local_abspath('.'),

                         branch,

                         inv,

                         _internal=True,

                         _format=self,

                         _bzrdir=a_bzrdir,

                         _control_files=control_files)

        wt.lock_tree_write()

        try:

            basis_tree = branch.repository.revision_tree(revision_id)

            # only set an explicit root id if there is one to set.

            if basis_tree.inventory.root is not None:

                wt.set_root_id(basis_tree.get_root_id())

            if revision_id == _mod_revision.NULL_REVISION:

                wt.set_parent_trees([])

            else:

                wt.set_parent_trees([(revision_id, basis_tree)])

            transform.build_tree(basis_tree, wt)

        finally:

            # Unlock in this order so that the unlock-triggers-flush in

            # WorkingTree is given a chance to fire.

            control_files.unlock()

            wt.unlock()

        return wt

    def _initial_inventory(self):

        return inventory.Inventory()

    def open(self, a_bzrdir, _found=False):

        """Return the WorkingTree object for a_bzrdir

        _found is a private parameter, do not use it. It is used to indicate

               if format probing has already been done.

        """

        if not _found:

            # we are being called directly and must probe.

            raise NotImplementedError

        if not isinstance(a_bzrdir.transport, LocalTransport):

            raise errors.NotLocalUrl(a_bzrdir.transport.base)

        wt = self._open(a_bzrdir, self._open_control_files(a_bzrdir))

        return wt

    def _open(self, a_bzrdir, control_files):

        """Open the tree itself.

        :param a_bzrdir: the dir for the tree.

        :param control_files: the control files for the tree.

        """

        return self._tree_class(a_bzrdir.root_transport.local_abspath('.'),

                                _internal=True,

                                _format=self,

                                _bzrdir=a_bzrdir,

                                _control_files=control_files)

    def __str__(self):

        return self.get_format_string()