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
17
from bzrlib.lazy_import import lazy_import
18
lazy_import(globals(), """
31
from bzrlib.decorators import (
15
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17
from cStringIO import StringIO
20
from warnings import warn
23
from bzrlib.decorators import (needs_read_lock,
25
import bzrlib.errors as errors
26
from bzrlib.errors import BzrError
27
from bzrlib.osutils import file_iterator, safe_unicode
28
from bzrlib.symbol_versioning import (
32
from bzrlib.trace import mutter, note
33
import bzrlib.transactions as transactions
34
import bzrlib.urlutils as urlutils
36
37
# XXX: The tracking here of lock counts and whether the lock is held is
37
38
# somewhat redundant with what's done in LockDir; the main difference is that
38
39
# LockableFiles permits reentrancy.
40
class _LockWarner(object):
41
"""Hold a counter for a lock and warn if GCed while the count is >= 1.
43
This is separate from LockableFiles because putting a __del__ on
44
LockableFiles can result in uncollectable cycles.
47
def __init__(self, repr):
52
if self.lock_count >= 1:
53
# There should have been a try/finally to unlock this.
54
warnings.warn("%r was gc'd while locked" % self.repr)
57
41
class LockableFiles(object):
58
42
"""Object representing a set of related files locked within the same scope.
60
This coordinates access to the lock along with providing a transaction.
44
These files are used by a WorkingTree, Repository or Branch, and should
45
generally only be touched by that object.
47
LockableFiles also provides some policy on top of Transport for encoding
48
control files as utf-8.
62
50
LockableFiles manage a lock count and can be locked repeatedly by
63
51
a single caller. (The underlying lock implementation generally does not
66
54
Instances of this class are often called control_files.
56
This object builds on top of a Transport, which is used to actually write
57
the files to disk, and an OSLock or LockDir, which controls how access to
58
the files is controlled. The particular type of locking used is set when
59
the object is constructed. In older formats OSLocks are used everywhere.
60
in newer formats a LockDir is used for Repositories and Branches, and
61
OSLocks for the local filesystem.
68
This class is now deprecated; code should move to using the Transport
69
directly for file operations and using the lock or CountedLock for
63
This class is now deprecated; code should move to using the Transport
64
directly for file operations and using the lock or CountedLock for
72
:ivar _lock: The real underlying lock (e.g. a LockDir)
73
:ivar _counted_lock: A lock decorated with a semaphore, so that it
77
68
# _lock_mode: None, or 'r' or 'w'
79
70
# _lock_count: If _lock_mode is true, a positive count of the number of
80
# times the lock has been taken *by this process*.
71
# times the lock has been taken *by this process*.
82
73
def __init__(self, transport, lock_name, lock_class):
83
74
"""Create a LockableFiles group
85
:param transport: Transport pointing to the directory holding the
76
:param transport: Transport pointing to the directory holding the
86
77
control files and lock.
87
78
:param lock_name: Name of the lock guarding these files.
88
79
:param lock_class: Class of lock strategy to use: typically
122
118
self._lock.break_lock()
124
120
def _escape(self, file_or_path):
125
"""DEPRECATED: Do not use outside this class"""
126
121
if not isinstance(file_or_path, basestring):
127
122
file_or_path = '/'.join(file_or_path)
128
123
if file_or_path == '':
130
return urlutils.escape(osutils.safe_unicode(file_or_path))
125
return urlutils.escape(safe_unicode(file_or_path))
132
127
def _find_modes(self):
133
128
"""Determine the appropriate modes for files and directories.
135
:deprecated: Replaced by BzrDir._find_creation_modes.
130
:deprecated: Replaced by BzrDir._find_modes.
137
# XXX: The properties created by this can be removed or deprecated
138
# once all the _get_text_store methods etc no longer use them.
141
133
st = self._transport.stat('.')
142
134
except errors.TransportNotPossible:
151
143
# Remove the sticky and execute bits for files
152
144
self._file_mode = self._dir_mode & ~07111
146
@deprecated_method(deprecated_in((1, 6, 0)))
147
def controlfilename(self, file_or_path):
148
"""Return location relative to branch.
150
:deprecated: Use Transport methods instead.
152
return self._transport.abspath(self._escape(file_or_path))
155
@deprecated_method(deprecated_in((1, 5, 0)))
156
def get(self, relpath):
157
"""Get a file as a bytestream.
159
:deprecated: Use a Transport instead of LockableFiles.
161
relpath = self._escape(relpath)
162
return self._transport.get(relpath)
165
@deprecated_method(deprecated_in((1, 5, 0)))
166
def get_utf8(self, relpath):
167
"""Get a file as a unicode stream.
169
:deprecated: Use a Transport instead of LockableFiles.
171
relpath = self._escape(relpath)
172
# DO NOT introduce an errors=replace here.
173
return codecs.getreader('utf-8')(self._transport.get(relpath))
176
@deprecated_method(deprecated_in((1, 6, 0)))
177
def put(self, path, file):
180
:param path: The path to put the file, relative to the .bzr control
182
:param file: A file-like or string object whose contents should be copied.
184
:deprecated: Use Transport methods instead.
186
self._transport.put_file(self._escape(path), file, mode=self._file_mode)
189
@deprecated_method(deprecated_in((1, 6, 0)))
190
def put_bytes(self, path, a_string):
191
"""Write a string of bytes.
193
:param path: The path to put the bytes, relative to the transport root.
194
:param a_string: A string object, whose exact bytes are to be copied.
196
:deprecated: Use Transport methods instead.
198
self._transport.put_bytes(self._escape(path), a_string,
199
mode=self._file_mode)
202
@deprecated_method(deprecated_in((1, 6, 0)))
203
def put_utf8(self, path, a_string):
204
"""Write a string, encoding as utf-8.
206
:param path: The path to put the string, relative to the transport root.
207
:param string: A string or unicode object whose contents should be copied.
209
:deprecated: Use Transport methods instead.
211
# IterableFile would not be needed if Transport.put took iterables
212
# instead of files. ADHB 2005-12-25
213
# RBC 20060103 surely its not needed anyway, with codecs transcode
215
# JAM 20060103 We definitely don't want encode(..., 'replace')
216
# these are valuable files which should have exact contents.
217
if not isinstance(a_string, basestring):
218
raise errors.BzrBadParameterNotString(a_string)
219
self.put_bytes(path, a_string.encode('utf-8'))
154
221
def leave_in_place(self):
155
222
"""Set this LockableFiles to not clear the physical lock on unlock."""
156
223
self._lock.leave_in_place()
174
241
some other way, and need to synchronise this object's state with that
244
# mutter("lock write: %s (%s)", self, self._lock_count)
177
245
# TODO: Upgrade locking to support using a Transport,
178
246
# and potentially a remote locking protocol
179
247
if self._lock_mode:
180
248
if self._lock_mode != 'w' or not self.get_transaction().writeable():
181
249
raise errors.ReadOnlyError(self)
182
250
self._lock.validate_token(token)
183
self._lock_warner.lock_count += 1
251
self._lock_count += 1
184
252
return self._token_from_lock
186
254
token_from_lock = self._lock.lock_write(token=token)
255
#note('write locking %s', self)
187
256
#traceback.print_stack()
188
257
self._lock_mode = 'w'
189
self._lock_warner.lock_count = 1
190
self._set_write_transaction()
259
self._set_transaction(transactions.WriteTransaction())
191
260
self._token_from_lock = token_from_lock
192
261
return token_from_lock
194
263
def lock_read(self):
264
# mutter("lock read: %s (%s)", self, self._lock_count)
195
265
if self._lock_mode:
196
266
if self._lock_mode not in ('r', 'w'):
197
267
raise ValueError("invalid lock mode %r" % (self._lock_mode,))
198
self._lock_warner.lock_count += 1
268
self._lock_count += 1
200
270
self._lock.lock_read()
271
#note('read locking %s', self)
201
272
#traceback.print_stack()
202
273
self._lock_mode = 'r'
203
self._lock_warner.lock_count = 1
204
self._set_read_transaction()
206
def _set_read_transaction(self):
207
"""Setup a read transaction."""
208
self._set_transaction(transactions.ReadOnlyTransaction())
209
# 5K may be excessive, but hey, its a knob.
210
self.get_transaction().set_cache_size(5000)
212
def _set_write_transaction(self):
213
"""Setup a write transaction."""
214
self._set_transaction(transactions.WriteTransaction())
216
@only_raises(errors.LockNotHeld, errors.LockBroken)
275
self._set_transaction(transactions.ReadOnlyTransaction())
276
# 5K may be excessive, but hey, its a knob.
277
self.get_transaction().set_cache_size(5000)
217
279
def unlock(self):
280
# mutter("unlock: %s (%s)", self, self._lock_count)
218
281
if not self._lock_mode:
219
return lock.cant_unlock_not_held(self)
220
if self._lock_warner.lock_count > 1:
221
self._lock_warner.lock_count -= 1
282
raise errors.LockNotHeld(self)
283
if self._lock_count > 1:
284
self._lock_count -= 1
286
#note('unlocking %s', self)
223
287
#traceback.print_stack()
224
288
self._finish_transaction()
226
290
self._lock.unlock()
228
self._lock_mode = self._lock_warner.lock_count = None
231
def _lock_count(self):
232
return self._lock_warner.lock_count
292
self._lock_mode = self._lock_count = None
234
294
def is_locked(self):
235
295
"""Return true if this LockableFiles group is locked"""
236
return self._lock_warner.lock_count >= 1
296
return self._lock_count >= 1
238
298
def get_physical_lock_status(self):
239
299
"""Return physical lock status.
241
301
Returns true if a lock is held on the transport. If no lock is held, or
242
302
the underlying locking mechanism does not support querying lock
243
303
status, false is returned.