1
# Copyright (C) 2005, 2006, 2008, 2009 Canonical Ltd
1
# Copyright (C) 2005 Canonical Ltd
3
3
# This program is free software; you can redistribute it and/or modify
4
4
# it under the terms of the GNU General Public License as published by
5
5
# the Free Software Foundation; either version 2 of the License, or
6
6
# (at your option) any later version.
8
8
# This program is distributed in the hope that it will be useful,
9
9
# but WITHOUT ANY WARRANTY; without even the implied warranty of
10
10
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11
11
# GNU General Public License for more details.
13
13
# You should have received a copy of the GNU General Public License
14
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
15
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17
from bzrlib.lazy_import import lazy_import
18
lazy_import(globals(), """
17
from cStringIO import StringIO
32
from bzrlib.decorators import (
37
# XXX: The tracking here of lock counts and whether the lock is held is
38
# somewhat redundant with what's done in LockDir; the main difference is that
39
# LockableFiles permits reentrancy.
41
class _LockWarner(object):
42
"""Hold a counter for a lock and warn if GCed while the count is >= 1.
44
This is separate from LockableFiles because putting a __del__ on
45
LockableFiles can result in uncollectable cycles.
48
def __init__(self, repr):
53
if self.lock_count >= 1:
54
# There should have been a try/finally to unlock this.
55
warnings.warn("%r was gc'd while locked" % self.repr)
21
from bzrlib.decorators import *
22
import bzrlib.errors as errors
23
from bzrlib.errors import LockError, ReadOnlyError
24
from bzrlib.osutils import file_iterator, safe_unicode
25
from bzrlib.symbol_versioning import *
26
from bzrlib.symbol_versioning import deprecated_method, zero_eight
27
from bzrlib.trace import mutter
28
import bzrlib.transactions as transactions
58
31
class LockableFiles(object):
59
"""Object representing a set of related files locked within the same scope.
61
This coordinates access to the lock along with providing a transaction.
63
LockableFiles manage a lock count and can be locked repeatedly by
64
a single caller. (The underlying lock implementation generally does not
67
Instances of this class are often called control_files.
69
This class is now deprecated; code should move to using the Transport
70
directly for file operations and using the lock or CountedLock for
73
:ivar _lock: The real underlying lock (e.g. a LockDir)
74
:ivar _counted_lock: A lock decorated with a semaphore, so that it
32
"""Object representing a set of files locked within the same scope
38
If _lock_mode is true, a positive count of the number of times the
39
lock has been taken *by this process*. Others may have compatible
43
Lock object from bzrlib.lock.
78
# _lock_mode: None, or 'r' or 'w'
80
# _lock_count: If _lock_mode is true, a positive count of the number of
81
# times the lock has been taken *by this process*.
83
def __init__(self, transport, lock_name, lock_class):
84
"""Create a LockableFiles group
86
:param transport: Transport pointing to the directory holding the
87
control files and lock.
88
:param lock_name: Name of the lock guarding these files.
89
:param lock_class: Class of lock strategy to use: typically
90
either LockDir or TransportLock.
49
# If set to False (by a plugin, etc) BzrBranch will not set the
50
# mode on created files or directories
54
def __init__(self, transport, lock_name):
92
56
self._transport = transport
93
57
self.lock_name = lock_name
94
58
self._transaction = None
95
self._lock_mode = None
96
self._lock_warner = _LockWarner(repr(self))
98
esc_name = self._escape(lock_name)
99
self._lock = lock_class(transport, esc_name,
100
file_modebits=self._file_mode,
101
dir_modebits=self._dir_mode)
102
self._counted_lock = counted_lock.CountedLock(self._lock)
104
def create_lock(self):
107
This should normally be called only when the LockableFiles directory
108
is first created on disk.
110
self._lock.create(mode=self._dir_mode)
113
return '%s(%r)' % (self.__class__.__name__,
116
return 'LockableFiles(%s, %s)' % (self.lock_name, self._transport.base)
118
def break_lock(self):
119
"""Break the lock of this lockable files group if it is held.
121
The current ui factory will be used to prompt for user conformation.
123
self._lock.break_lock()
62
if self._lock_mode or self._lock:
63
# XXX: This should show something every time, and be suitable for
64
# headless operation and embedding
65
from warnings import warn
66
warn("file group %r was not explicitly unlocked" % self)
125
69
def _escape(self, file_or_path):
126
"""DEPRECATED: Do not use outside this class"""
127
70
if not isinstance(file_or_path, basestring):
128
71
file_or_path = '/'.join(file_or_path)
129
72
if file_or_path == '':
131
return urlutils.escape(osutils.safe_unicode(file_or_path))
74
return bzrlib.transport.urlescape(safe_unicode(file_or_path))
133
76
def _find_modes(self):
134
"""Determine the appropriate modes for files and directories.
136
:deprecated: Replaced by BzrDir._find_creation_modes.
138
# XXX: The properties created by this can be removed or deprecated
139
# once all the _get_text_store methods etc no longer use them.
77
"""Determine the appropriate modes for files and directories."""
142
79
st = self._transport.stat('.')
143
80
except errors.TransportNotPossible:
144
81
self._dir_mode = 0755
145
82
self._file_mode = 0644
147
# Check the directory mode, but also make sure the created
148
# directories and files are read-write for this user. This is
149
# mostly a workaround for filesystems which lie about being able to
150
# write to a directory (cygwin & win32)
151
self._dir_mode = (st.st_mode & 07777) | 00700
84
self._dir_mode = st.st_mode & 07777
152
85
# Remove the sticky and execute bits for files
153
86
self._file_mode = self._dir_mode & ~07111
155
def leave_in_place(self):
156
"""Set this LockableFiles to not clear the physical lock on unlock."""
157
self._lock.leave_in_place()
159
def dont_leave_in_place(self):
160
"""Set this LockableFiles to clear the physical lock on unlock."""
161
self._lock.dont_leave_in_place()
163
def lock_write(self, token=None):
164
"""Lock this group of files for writing.
166
:param token: if this is already locked, then lock_write will fail
167
unless the token matches the existing lock.
168
:returns: a token if this instance supports tokens, otherwise None.
169
:raises TokenLockingNotSupported: when a token is given but this
170
instance doesn't support using token locks.
171
:raises MismatchedToken: if the specified token doesn't match the token
172
of the existing lock.
174
A token should be passed in if you know that you have locked the object
175
some other way, and need to synchronise this object's state with that
87
if not self._set_dir_mode:
89
if not self._set_file_mode:
90
self._file_mode = None
92
def controlfilename(self, file_or_path):
93
"""Return location relative to branch."""
94
return self._transport.abspath(self._escape(file_or_path))
96
@deprecated_method(zero_eight)
97
def controlfile(self, file_or_path, mode='r'):
98
"""Open a control file for this branch.
100
There are two classes of file in a lockable directory: text
101
and binary. binary files are untranslated byte streams. Text
102
control files are stored with Unix newlines and in UTF-8, even
103
if the platform or locale defaults are different.
105
Such files are not openable in write mode : they are managed via
106
put and put_utf8 which atomically replace old versions using
110
relpath = self._escape(file_or_path)
111
#TODO: codecs.open() buffers linewise, so it was overloaded with
112
# a much larger buffer, do we need to do the same for getreader/getwriter?
114
return self.get(relpath)
116
raise BzrError("Branch.controlfile(mode='wb') is not supported, use put[_utf8]")
118
return self.get_utf8(relpath)
120
raise BzrError("Branch.controlfile(mode='w') is not supported, use put[_utf8]")
122
raise BzrError("invalid controlfile mode %r" % mode)
125
def get(self, relpath):
126
"""Get a file as a bytestream."""
127
relpath = self._escape(relpath)
128
return self._transport.get(relpath)
131
def get_utf8(self, relpath):
132
"""Get a file as a unicode stream."""
133
relpath = self._escape(relpath)
134
# DO NOT introduce an errors=replace here.
135
return codecs.getreader('utf-8')(self._transport.get(relpath))
138
def put(self, path, file):
141
:param path: The path to put the file, relative to the .bzr control
143
:param f: A file-like or string object whose contents should be copied.
145
self._transport.put(self._escape(path), file, mode=self._file_mode)
148
def put_utf8(self, path, a_string):
149
"""Write a string, encoding as utf-8.
151
:param path: The path to put the string, relative to the transport root.
152
:param string: A file-like or string object whose contents should be copied.
154
# IterableFile would not be needed if Transport.put took iterables
155
# instead of files. ADHB 2005-12-25
156
# RBC 20060103 surely its not needed anyway, with codecs transcode
158
# JAM 20060103 We definitely don't want encode(..., 'replace')
159
# these are valuable files which should have exact contents.
160
if not isinstance(a_string, basestring):
161
raise errors.BzrBadParameterNotString(a_string)
162
self.put(path, StringIO(a_string.encode('utf-8')))
164
def lock_write(self):
165
# mutter("lock write: %s (%s)", self, self._lock_count)
178
166
# TODO: Upgrade locking to support using a Transport,
179
167
# and potentially a remote locking protocol
180
168
if self._lock_mode:
181
if self._lock_mode != 'w' or not self.get_transaction().writeable():
182
raise errors.ReadOnlyError(self)
183
self._lock.validate_token(token)
184
self._lock_warner.lock_count += 1
185
return self._token_from_lock
169
if self._lock_mode != 'w':
170
raise ReadOnlyError("can't upgrade to a write lock from %r" %
172
self._lock_count += 1
187
token_from_lock = self._lock.lock_write(token=token)
188
#traceback.print_stack()
174
self._lock = self._transport.lock_write(
175
self._escape(self.lock_name))
189
176
self._lock_mode = 'w'
190
self._lock_warner.lock_count = 1
191
self._set_write_transaction()
192
self._token_from_lock = token_from_lock
193
return token_from_lock
178
self._set_transaction(transactions.PassThroughTransaction())
195
180
def lock_read(self):
181
# mutter("lock read: %s (%s)", self, self._lock_count)
196
182
if self._lock_mode:
197
if self._lock_mode not in ('r', 'w'):
198
raise ValueError("invalid lock mode %r" % (self._lock_mode,))
199
self._lock_warner.lock_count += 1
183
assert self._lock_mode in ('r', 'w'), \
184
"invalid lock mode %r" % self._lock_mode
185
self._lock_count += 1
201
self._lock.lock_read()
202
#traceback.print_stack()
187
self._lock = self._transport.lock_read(
188
self._escape(self.lock_name))
203
189
self._lock_mode = 'r'
204
self._lock_warner.lock_count = 1
205
self._set_read_transaction()
207
def _set_read_transaction(self):
208
"""Setup a read transaction."""
209
self._set_transaction(transactions.ReadOnlyTransaction())
210
# 5K may be excessive, but hey, its a knob.
211
self.get_transaction().set_cache_size(5000)
213
def _set_write_transaction(self):
214
"""Setup a write transaction."""
215
self._set_transaction(transactions.WriteTransaction())
217
@only_raises(errors.LockNotHeld, errors.LockBroken)
191
self._set_transaction(transactions.ReadOnlyTransaction())
192
# 5K may be excessive, but hey, its a knob.
193
self.get_transaction().set_cache_size(5000)
218
195
def unlock(self):
196
# mutter("unlock: %s (%s)", self, self._lock_count)
219
197
if not self._lock_mode:
220
return lock.cant_unlock_not_held(self)
221
if self._lock_warner.lock_count > 1:
222
self._lock_warner.lock_count -= 1
198
raise LockError('branch %r is not locked' % (self))
200
if self._lock_count > 1:
201
self._lock_count -= 1
224
#traceback.print_stack()
225
203
self._finish_transaction()
229
self._lock_mode = self._lock_warner.lock_count = None
232
def _lock_count(self):
233
return self._lock_warner.lock_count
236
"""Return true if this LockableFiles group is locked"""
237
return self._lock_warner.lock_count >= 1
239
def get_physical_lock_status(self):
240
"""Return physical lock status.
242
Returns true if a lock is held on the transport. If no lock is held, or
243
the underlying locking mechanism does not support querying lock
244
status, false is returned.
247
return self._lock.peek() is not None
248
except NotImplementedError:
206
self._lock_mode = self._lock_count = None
251
208
def get_transaction(self):
252
209
"""Return the current active transaction.
added
removed
bzrlib/lockable_files.py
