1# Copyright (C) 2010 Canonical Ltd
2#
3# This program is free software; you can redistribute it and/or modify
4# it under the terms of the GNU General Public License as published by
5# the Free Software Foundation; either version 2 of the License, or
6# (at your option) any later version.
7#
8# This program is distributed in the hope that it will be useful,
9# but WITHOUT ANY WARRANTY; without even the implied warranty of
10# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11# GNU General Public License for more details.
12#
13# You should have received a copy of the GNU General Public License
14# along with this program; if not, write to the Free Software
15# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
16
17"""Weave-era branch implementations."""
18
19from ... import (
20    errors,
21    lockable_files,
22    )
23
24from ...decorators import (
25    only_raises,
26    )
27from ...lock import LogicalLockResult
28from ...trace import mutter
29
30from ...branch import (
31    BranchFormat,
32    BranchWriteLockResult,
33    )
34from ...bzr.fullhistory import (
35    FullHistoryBzrBranch,
36    )
37
38
39class BzrBranch4(FullHistoryBzrBranch):
40    """Branch format 4."""
41
42    def lock_write(self, token=None):
43        """Lock the branch for write operations.
44
45        :param token: A token to permit reacquiring a previously held and
46            preserved lock.
47        :return: A BranchWriteLockResult.
48        """
49        if not self.is_locked():
50            self._note_lock('w')
51        # All-in-one needs to always unlock/lock.
52        self.repository._warn_if_deprecated(self)
53        self.repository.lock_write()
54        try:
55            return BranchWriteLockResult(self.unlock,
56                                         self.control_files.lock_write(token=token))
57        except:
58            self.repository.unlock()
59            raise
60
61    def lock_read(self):
62        """Lock the branch for read operations.
63
64        :return: A breezy.lock.LogicalLockResult.
65        """
66        if not self.is_locked():
67            self._note_lock('r')
68        # All-in-one needs to always unlock/lock.
69        self.repository._warn_if_deprecated(self)
70        self.repository.lock_read()
71        try:
72            self.control_files.lock_read()
73            return LogicalLockResult(self.unlock)
74        except:
75            self.repository.unlock()
76            raise
77
78    @only_raises(errors.LockNotHeld, errors.LockBroken)
79    def unlock(self):
80        if self.control_files._lock_count == 2 and self.conf_store is not None:
81            self.conf_store.save_changes()
82        try:
83            self.control_files.unlock()
84        finally:
85            # All-in-one needs to always unlock/lock.
86            self.repository.unlock()
87            if not self.control_files.is_locked():
88                # we just released the lock
89                self._clear_cached_state()
90
91    def _get_checkout_format(self, lightweight=False):
92        """Return the most suitable metadir for a checkout of this branch.
93        """
94        from .repository import RepositoryFormat7
95        from ...bzr.bzrdir import BzrDirMetaFormat1
96        format = BzrDirMetaFormat1()
97        if lightweight:
98            format.set_branch_format(self._format)
99            format.repository_format = self.controldir._format.repository_format
100        else:
101            format.repository_format = RepositoryFormat7()
102        return format
103
104    def unbind(self):
105        raise errors.UpgradeRequired(self.user_url)
106
107    def bind(self, other):
108        raise errors.UpgradeRequired(self.user_url)
109
110    def set_bound_location(self, location):
111        raise NotImplementedError(self.set_bound_location)
112
113    def get_bound_location(self):
114        return None
115
116    def update(self):
117        return None
118
119    def get_master_branch(self, possible_transports=None):
120        return None
121
122
123class BzrBranchFormat4(BranchFormat):
124    """Bzr branch format 4.
125
126    This format has:
127     - a revision-history file.
128     - a branch-lock lock file [ to be shared with the bzrdir ]
129
130    It does not support binding.
131    """
132
133    def initialize(self, a_controldir, name=None, repository=None,
134                   append_revisions_only=None):
135        """Create a branch of this format in a_controldir.
136
137        :param a_controldir: The bzrdir to initialize the branch in
138        :param name: Name of colocated branch to create, if any
139        :param repository: Repository for this branch (unused)
140        """
141        if append_revisions_only:
142            raise errors.UpgradeRequired(a_controldir.user_url)
143        if repository is not None:
144            raise NotImplementedError(
145                "initialize(repository=<not None>) on %r" % (self,))
146        if not [isinstance(a_controldir._format, format) for format in
147                self._compatible_bzrdirs]:
148            raise errors.IncompatibleFormat(self, a_controldir._format)
149        utf8_files = [('revision-history', b''),
150                      ('branch-name', b''),
151                      ]
152        mutter('creating branch %r in %s', self, a_controldir.user_url)
153        branch_transport = a_controldir.get_branch_transport(self, name=name)
154        control_files = lockable_files.LockableFiles(branch_transport,
155                                                     'branch-lock', lockable_files.TransportLock)
156        control_files.create_lock()
157        try:
158            control_files.lock_write()
159        except errors.LockContention:
160            lock_taken = False
161        else:
162            lock_taken = True
163        try:
164            for (filename, content) in utf8_files:
165                branch_transport.put_bytes(
166                    filename, content,
167                    mode=a_controldir._get_file_mode())
168        finally:
169            if lock_taken:
170                control_files.unlock()
171        branch = self.open(a_controldir, name, _found=True,
172                           found_repository=None)
173        self._run_post_branch_init_hooks(a_controldir, name, branch)
174        return branch
175
176    def __init__(self):
177        super(BzrBranchFormat4, self).__init__()
178        from .bzrdir import (
179            BzrDirFormat4, BzrDirFormat5, BzrDirFormat6,
180            )
181        self._matchingcontroldir = BzrDirFormat6()
182        self._compatible_bzrdirs = [BzrDirFormat4, BzrDirFormat5,
183                                    BzrDirFormat6]
184
185    def network_name(self):
186        """The network name for this format is the control dirs disk label."""
187        return self._matchingcontroldir.get_format_string()
188
189    def get_format_description(self):
190        return "Branch format 4"
191
192    def open(self, a_controldir, name=None, _found=False, ignore_fallbacks=False,
193             found_repository=None, possible_transports=None):
194        """See BranchFormat.open()."""
195        if name is None:
196            name = a_controldir._get_selected_branch()
197        if name != "":
198            raise errors.NoColocatedBranchSupport(self)
199        if not _found:
200            # we are being called directly and must probe.
201            raise NotImplementedError
202        if found_repository is None:
203            found_repository = a_controldir.open_repository()
204        return BzrBranch4(_format=self,
205                          _control_files=a_controldir._control_files,
206                          a_controldir=a_controldir,
207                          name=name,
208                          _repository=found_repository,
209                          possible_transports=possible_transports)
210
211    def __str__(self):
212        return "Bazaar-NG branch format 4"
213
214    def supports_leaving_lock(self):
215        return False
216
217    supports_reference_locations = False
218