def lock(self, blocking=True):
"""
lock the file
:param blocking:
If blocking is True, will block there until cup gets the lock.
True by default.
:return:
return False if locking fails
:raise Exception:
raise cup.err.LockFileError if blocking is False and
the lock action failed
"""
flags = 0x1
if FILELOCK_SHARED == self._locktype:
flags = FILELOCK_SHARED
elif FILELOCK_EXCLUSIVE == self._locktype:
flags = FILELOCK_EXCLUSIVE
else:
raise err.LockFileError('does not support this lock type')
if not blocking:
flags |= FILELOCK_NONBLOCKING
ret = None
try:
ret = fcntl.flock(self._fhandle, flags)
except IOError as error:
raise err.LockFileError(error)
except Exception as error:
raise err.LockFileError(error)
return ret
def __init__(self, fpath, locktype=FILELOCK_EXCLUSIVE):
"""
exclusive lockfile, by default.
Notice that the file CANNOT exist before you intialize a LockFile obj.
Otherwise, it will raise cup.err.LockFileError
:raise:
cup.err.LockFileError if we encounter errors
"""
self._fpath = fpath
self._locktype = locktype
self._fhandle = None
try:
# if FILELOCK_EXCLUSIVE == locktype:
# self._fhandle = os.open(
# self._fpath, os.O_CREAT|os.O_EXCL|os.O_RDWR
# )
# else:
self._fhandle = os.open(self._fpath, os.O_CREAT | os.O_RDWR)
except IOError as error:
raise err.LockFileError(error)
except OSError as error:
raise err.LockFileError(error)
except Exception as error:
raise err.LockFileError(
'catch unkown error type:{0}'.format(error))
def unlock(self):
"""unlock the locked file"""
if platforms.is_linux():
try:
fcntl.flock(self._fhandle, FILELOCK_UNLOCK)
except Exception as error:
raise err.LockFileError(error)
elif platforms.is_windows():
win_unlockfile(self._fhandle)
def unlock(self):
"""unlock the locked file"""
try:
fcntl.flock(self._fhandle, FILELOCK_UNLOCK)
except Exception as error:
raise err.LockFileError(error)
