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29
Eventually we may need to use some kind of lock representation that
30
30
will work on a dumb filesystem without actual locking primitives.
32
This defines two classes: ReadLock and WriteLock, which can be
33
implemented in different ways on different platforms. Both have an
37
from trace import mutter, note, warning
38
from errors import LockError
41
from bzrlib.trace import mutter, note, warning
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from bzrlib.errors import LockError
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class _base_Lock(object):
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def _open(self, filename, filemode):
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self.f = open(filename, filemode)
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if e.errno != errno.ENOENT:
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# maybe this is an old branch (before may 2005)
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mutter("trying to create missing branch lock %r" % filename)
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self.f = open(filename, 'wb')
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from warnings import warn
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warn("lock on %r not released" % self.f)
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raise NotImplementedError()
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############################################################
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LOCK_SH = fcntl.LOCK_SH
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LOCK_EX = fcntl.LOCK_EX
44
LOCK_NB = fcntl.LOCK_NB
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fcntl.flock(f, fcntl.LOCK_UN)
83
class _fcntl_FileLock(_base_Lock):
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fcntl.flock(self.f, fcntl.LOCK_UN)
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class _fcntl_WriteLock(_fcntl_FileLock):
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def __init__(self, filename):
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fcntl.flock(self._open(filename, 'wb'), fcntl.LOCK_EX)
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class _fcntl_ReadLock(_fcntl_FileLock):
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def __init__(self, filename):
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fcntl.flock(self._open(filename, 'rb'), fcntl.LOCK_SH)
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WriteLock = _fcntl_WriteLock
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ReadLock = _fcntl_ReadLock
57
110
except ImportError:
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112
import win32con, win32file, pywintypes
60
LOCK_SH = 0 # the default
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LOCK_EX = win32con.LOCKFILE_EXCLUSIVE_LOCK
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LOCK_NB = win32con.LOCKFILE_FAIL_IMMEDIATELY
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hfile = win32file._get_osfhandle(f.fileno())
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hfile = win32file._get_osfhandle(f)
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overlapped = pywintypes.OVERLAPPED()
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win32file.LockFileEx(hfile, flags, 0, 0x7fff0000, overlapped)
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hfile = win32file._get_osfhandle(f.fileno())
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hfile = win32file._get_osfhandle(f)
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overlapped = pywintypes.OVERLAPPED()
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win32file.UnlockFileEx(hfile, 0, 0x7fff0000, overlapped)
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#LOCK_SH = 0 # the default
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#LOCK_EX = win32con.LOCKFILE_EXCLUSIVE_LOCK
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#LOCK_NB = win32con.LOCKFILE_FAIL_IMMEDIATELY
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class _w32c_FileLock(_base_Lock):
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def _lock(self, filename, openmode, lockmode):
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self._open(filename, openmode)
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self.hfile = win32file._get_osfhandle(self.f.fileno())
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overlapped = pywintypes.OVERLAPPED()
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win32file.LockFileEx(self.hfile, lockmode, 0, 0x7fff0000, overlapped)
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overlapped = pywintypes.OVERLAPPED()
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win32file.UnlockFileEx(self.hfile, 0, 0x7fff0000, overlapped)
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class _w32c_ReadLock(_w32c_FileLock):
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def __init__(self, filename):
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_w32c_FileLock._lock(self, filename, 'rb', 0)
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class _w32c_WriteLock(_w32c_FileLock):
145
def __init__(self, filename):
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_w32c_FileLock._lock(self, filename, 'wb',
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win32con.LOCKFILE_EXCLUSIVE_LOCK)
151
WriteLock = _w32c_WriteLock
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ReadLock = _w32c_ReadLock
85
154
except ImportError:
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159
# Unfortunately, msvcrt.locking() doesn't distinguish between
89
160
# read locks and write locks. Also, the way the combinations
90
161
# work to get non-blocking is not the same, so we
91
162
# have to write extra special functions here.
165
class _msvc_FileLock(_base_Lock):
173
class _msvc_ReadLock(_msvc_FileLock):
174
def __init__(self, filename):
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_msvc_lock(self._open(filename, 'rb'), self.LOCK_SH)
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class _msvc_WriteLock(_msvc_FileLock):
179
def __init__(self, filename):
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_msvc_lock(self._open(filename, 'wb'), self.LOCK_EX)
184
def _msvc_lock(f, flags):
99
186
# Unfortunately, msvcrt.LK_RLCK is equivalent to msvcrt.LK_LOCK
100
187
# according to the comments, LK_RLCK is open the lock for writing.
added
removed
bzrlib/lock.py
