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# Copyright (C) 2005, 2006, 2008, 2009 Canonical Ltd
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# Copyright (C) 2005, 2006, 2008 Canonical Ltd
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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from cStringIO import StringIO
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# somewhat redundant with what's done in LockDir; the main difference is that
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# LockableFiles permits reentrancy.
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class _LockWarner(object):
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"""Hold a counter for a lock and warn if GCed while the count is >= 1.
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This is separate from LockableFiles because putting a __del__ on
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LockableFiles can result in uncollectable cycles.
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def __init__(self, repr):
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if self.lock_count >= 1:
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# There should have been a try/finally to unlock this.
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warnings.warn("%r was gc'd while locked" % self.repr)
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class LockableFiles(object):
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"""Object representing a set of related files locked within the same scope.
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This class is now deprecated; code should move to using the Transport
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directly for file operations and using the lock or CountedLock for
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:ivar _lock: The real underlying lock (e.g. a LockDir)
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:ivar _counted_lock: A lock decorated with a semaphore, so that it
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# _lock_mode: None, or 'r' or 'w'
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self.lock_name = lock_name
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self._transaction = None
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self._lock_mode = None
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self._lock_warner = _LockWarner(repr(self))
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self._find_modes()
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esc_name = self._escape(lock_name)
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self._lock = lock_class(transport, esc_name,
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file_modebits=self._file_mode,
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dir_modebits=self._dir_mode)
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self._counted_lock = counted_lock.CountedLock(self._lock)
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def create_lock(self):
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"""Create the lock.
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def __str__(self):
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return 'LockableFiles(%s, %s)' % (self.lock_name, self._transport.base)
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# do not automatically unlock; there should have been a
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# try/finally to unlock this.
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warnings.warn("%r was gc'd while locked" % self)
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def break_lock(self):
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"""Break the lock of this lockable files group if it is held.
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:deprecated: Replaced by BzrDir._find_modes.
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# XXX: The properties created by this can be removed or deprecated
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# once all the _get_text_store methods etc no longer use them.
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st = self._transport.stat('.')
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except errors.TransportNotPossible:
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if self._lock_mode != 'w' or not self.get_transaction().writeable():
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raise errors.ReadOnlyError(self)
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self._lock.validate_token(token)
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self._lock_warner.lock_count += 1
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self._lock_count += 1
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return self._token_from_lock
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token_from_lock = self._lock.lock_write(token=token)
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#traceback.print_stack()
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self._lock_mode = 'w'
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self._lock_warner.lock_count = 1
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self._set_write_transaction()
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self._set_transaction(transactions.WriteTransaction())
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self._token_from_lock = token_from_lock
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return token_from_lock
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if self._lock_mode:
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if self._lock_mode not in ('r', 'w'):
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raise ValueError("invalid lock mode %r" % (self._lock_mode,))
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self._lock_warner.lock_count += 1
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self._lock_count += 1
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self._lock.lock_read()
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#traceback.print_stack()
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self._lock_mode = 'r'
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self._lock_warner.lock_count = 1
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self._set_read_transaction()
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def _set_read_transaction(self):
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"""Setup a read transaction."""
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self._set_transaction(transactions.ReadOnlyTransaction())
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# 5K may be excessive, but hey, its a knob.
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self.get_transaction().set_cache_size(5000)
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def _set_write_transaction(self):
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"""Setup a write transaction."""
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self._set_transaction(transactions.WriteTransaction())
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self._set_transaction(transactions.ReadOnlyTransaction())
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# 5K may be excessive, but hey, its a knob.
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self.get_transaction().set_cache_size(5000)
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def unlock(self):
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if not self._lock_mode:
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raise errors.LockNotHeld(self)
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if self._lock_warner.lock_count > 1:
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self._lock_warner.lock_count -= 1
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if self._lock_count > 1:
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self._lock_count -= 1
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#traceback.print_stack()
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self._finish_transaction()
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self._lock.unlock()
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self._lock_mode = self._lock_warner.lock_count = None
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def _lock_count(self):
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return self._lock_warner.lock_count
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self._lock_mode = self._lock_count = None
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def is_locked(self):
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"""Return true if this LockableFiles group is locked"""
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return self._lock_warner.lock_count >= 1
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return self._lock_count >= 1
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def get_physical_lock_status(self):
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"""Return physical lock status.
added
removed
bzrlib/lockable_files.py
