42
40
from bzrlib import (
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from bzrlib.hooks import HookPoint, Hooks
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class LockHooks(Hooks):
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self.create_hook(HookPoint('lock_acquired',
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"Called with a bzrlib.lock.LockResult when a physical lock is "
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"acquired.", (1, 8), None))
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self.create_hook(HookPoint('lock_released',
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"Called with a bzrlib.lock.LockResult when a physical lock is "
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"released.", (1, 8), None))
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self.create_hook(HookPoint('lock_broken',
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"Called with a bzrlib.lock.LockResult when a physical lock is "
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"broken.", (1, 15), None))
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"""Base class for locks.
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:cvar hooks: Hook dictionary for operations on locks.
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class LockResult(object):
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"""Result of an operation on a lock; passed to a hook"""
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def __init__(self, lock_url, details=None):
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"""Create a lock result for lock with optional details about the lock."""
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self.lock_url = lock_url
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self.details = details
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def __eq__(self, other):
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return self.lock_url == other.lock_url and self.details == other.details
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return '%s(%s%s)' % (self.__class__.__name__,
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self.lock_url, self.details)
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def cant_unlock_not_held(locked_object):
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"""An attempt to unlock failed because the object was not locked.
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This provides a policy point from which we can generate either a warning
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# This is typically masking some other error and called from a finally
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# block, so it's useful to have the option not to generate a new error
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# here. You can use -Werror to make it fatal. It should possibly also
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if 'unlock' in debug.debug_flags:
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warnings.warn("%r is already unlocked" % (locked_object,),
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raise errors.LockNotHeld(locked_object)
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have_ctypes_win32 = False
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if sys.platform == 'win32':
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import win32file, pywintypes, winerror
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have_ctypes_win32 = True
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class _OSLock(object):
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if have_pywin32 and sys.platform == 'win32':
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if os.path.supports_unicode_filenames:
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# for Windows NT/2K/XP/etc
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win32file_CreateFile = win32file.CreateFileW
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win32file_CreateFile = win32file.CreateFile
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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(_OSLock):
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def _open(self, filename, access, share, cflags, pymode):
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self.filename = osutils.realpath(filename)
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def _lock(self, filename, openmode, lockmode):
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self._open(filename, openmode)
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self.hfile = msvcrt.get_osfhandle(self.f.fileno())
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overlapped = pywintypes.OVERLAPPED()
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self._handle = win32file_CreateFile(filename, access, share,
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None, win32file.OPEN_ALWAYS,
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win32file.FILE_ATTRIBUTE_NORMAL, None)
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win32file.LockFileEx(self.hfile, lockmode, 0, 0x7fff0000,
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except pywintypes.error, e:
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if e.args[0] == winerror.ERROR_ACCESS_DENIED:
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raise errors.LockFailed(filename, e)
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if e.args[0] == winerror.ERROR_SHARING_VIOLATION:
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raise errors.LockContention(filename, e)
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if e.args[0] in (winerror.ERROR_LOCK_VIOLATION,):
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raise errors.LockContention(filename)
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## import pdb; pdb.set_trace()
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fd = win32file._open_osfhandle(self._handle, cflags)
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self.f = os.fdopen(fd, pymode)
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raise errors.LockContention(e)
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def unlock(self):
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overlapped = pywintypes.OVERLAPPED()
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win32file.UnlockFileEx(self.hfile, 0, 0x7fff0000, overlapped)
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raise errors.LockContention(e)
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class _w32c_ReadLock(_w32c_FileLock):
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291
def __init__(self, filename):
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292
super(_w32c_ReadLock, self).__init__()
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self._open(filename, win32file.GENERIC_READ,
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win32file.FILE_SHARE_READ, os.O_RDONLY, "rb")
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self._lock(filename, 'rb', LOCK_SH + LOCK_NB)
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295
def temporary_write_lock(self):
360
296
"""Try to grab a write lock on the file.
394
328
_lock_classes.append(('pywin32', _w32c_WriteLock, _w32c_ReadLock))
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if have_ctypes_win32:
398
from ctypes.wintypes import DWORD, LPCSTR, LPCWSTR
399
LPSECURITY_ATTRIBUTES = ctypes.c_void_p # used as NULL no need to declare
400
HANDLE = ctypes.c_int # rather than unsigned as in ctypes.wintypes
401
if os.path.supports_unicode_filenames:
402
_function_name = "CreateFileW"
405
_function_name = "CreateFileA"
406
class LPTSTR(LPCSTR):
407
def __new__(cls, obj):
408
return LPCSTR.__new__(cls, obj.encode("mbcs"))
410
# CreateFile <http://msdn.microsoft.com/en-us/library/aa363858.aspx>
411
_CreateFile = ctypes.WINFUNCTYPE(
412
HANDLE, # return value
414
DWORD, # dwDesiredAccess
416
LPSECURITY_ATTRIBUTES, # lpSecurityAttributes
417
DWORD, # dwCreationDisposition
418
DWORD, # dwFlagsAndAttributes
419
HANDLE # hTemplateFile
420
)((_function_name, ctypes.windll.kernel32))
422
INVALID_HANDLE_VALUE = -1
424
GENERIC_READ = 0x80000000
425
GENERIC_WRITE = 0x40000000
428
FILE_ATTRIBUTE_NORMAL = 128
430
ERROR_ACCESS_DENIED = 5
431
ERROR_SHARING_VIOLATION = 32
331
if have_ctypes and sys.platform == 'win32':
332
# These constants were copied from the win32con.py module.
333
LOCKFILE_FAIL_IMMEDIATELY = 1
334
LOCKFILE_EXCLUSIVE_LOCK = 2
335
# Constant taken from winerror.py module
336
ERROR_LOCK_VIOLATION = 33
339
LOCK_EX = LOCKFILE_EXCLUSIVE_LOCK
340
LOCK_NB = LOCKFILE_FAIL_IMMEDIATELY
341
_LockFileEx = ctypes.windll.kernel32.LockFileEx
342
_UnlockFileEx = ctypes.windll.kernel32.UnlockFileEx
343
_GetLastError = ctypes.windll.kernel32.GetLastError
345
### Define the OVERLAPPED structure.
346
# http://msdn2.microsoft.com/en-us/library/ms684342.aspx
347
# typedef struct _OVERLAPPED {
348
# ULONG_PTR Internal;
349
# ULONG_PTR InternalHigh;
360
class _inner_struct(ctypes.Structure):
361
_fields_ = [('Offset', ctypes.c_uint), # DWORD
362
('OffsetHigh', ctypes.c_uint), # DWORD
365
class _inner_union(ctypes.Union):
366
_fields_ = [('anon_struct', _inner_struct), # struct
367
('Pointer', ctypes.c_void_p), # PVOID
370
class OVERLAPPED(ctypes.Structure):
371
_fields_ = [('Internal', ctypes.c_void_p), # ULONG_PTR
372
('InternalHigh', ctypes.c_void_p), # ULONG_PTR
373
('_inner_union', _inner_union),
374
('hEvent', ctypes.c_void_p), # HANDLE
433
377
class _ctypes_FileLock(_OSLock):
435
def _open(self, filename, access, share, cflags, pymode):
436
self.filename = osutils.realpath(filename)
437
handle = _CreateFile(filename, access, share, None, OPEN_ALWAYS,
438
FILE_ATTRIBUTE_NORMAL, 0)
439
if handle in (INVALID_HANDLE_VALUE, 0):
440
e = ctypes.WinError()
441
if e.args[0] == ERROR_ACCESS_DENIED:
442
raise errors.LockFailed(filename, e)
443
if e.args[0] == ERROR_SHARING_VIOLATION:
444
raise errors.LockContention(filename, e)
446
fd = msvcrt.open_osfhandle(handle, cflags)
447
self.f = os.fdopen(fd, pymode)
379
def _lock(self, filename, openmode, lockmode):
380
self._open(filename, openmode)
382
self.hfile = msvcrt.get_osfhandle(self.f.fileno())
383
overlapped = OVERLAPPED()
384
result = _LockFileEx(self.hfile, # HANDLE hFile
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lockmode, # DWORD dwFlags
386
0, # DWORD dwReserved
387
0x7fffffff, # DWORD nNumberOfBytesToLockLow
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0x00000000, # DWORD nNumberOfBytesToLockHigh
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ctypes.byref(overlapped), # lpOverlapped
393
last_err = _GetLastError()
394
if last_err in (ERROR_LOCK_VIOLATION,):
395
raise errors.LockContention(filename)
396
raise errors.LockContention('Unknown locking error: %s'
450
399
def unlock(self):
400
overlapped = OVERLAPPED()
401
result = _UnlockFileEx(self.hfile, # HANDLE hFile
402
0, # DWORD dwReserved
403
0x7fffffff, # DWORD nNumberOfBytesToLockLow
404
0x00000000, # DWORD nNumberOfBytesToLockHigh
405
ctypes.byref(overlapped), # lpOverlapped
410
last_err = _GetLastError()
411
raise errors.LockContention('Unknown unlocking error: %s'
454
415
class _ctypes_ReadLock(_ctypes_FileLock):
455
416
def __init__(self, filename):
456
417
super(_ctypes_ReadLock, self).__init__()
457
self._open(filename, GENERIC_READ, FILE_SHARE_READ, os.O_RDONLY,
418
self._lock(filename, 'rb', LOCK_SH + LOCK_NB)
460
420
def temporary_write_lock(self):
461
421
"""Try to grab a write lock on the file.
added
removed
bzrlib/lock.py
