def open_and_lock(self, timeout, delay):
"""Open the file and lock it.
Args:
timeout: float, How long to try to lock for.
delay: float, How long to wait between retries
Raises:
AlreadyLockedException: if the lock is already acquired.
IOError: if the open fails.
CredentialsFileSymbolicLinkError: if the file is a symbolic
link.
"""
if self._locked:
raise AlreadyLockedException('File %s is already locked' %
self._filename)
start_time = time.time()
validate_file(self._filename)
try:
self._fh = open(self._filename, self._mode)
except IOError as e:
# If we can't access with _mode, try _fallback_mode
# and don't lock.
if e.errno == errno.EACCES:
self._fh = open(self._filename, self._fallback_mode)
return
# We opened in _mode, try to lock the file.
while True:
try:
hfile = win32file._get_osfhandle(self._fh.fileno())
win32file.LockFileEx(
hfile,
(win32con.LOCKFILE_FAIL_IMMEDIATELY |
win32con.LOCKFILE_EXCLUSIVE_LOCK), 0, -0x10000,
pywintypes.OVERLAPPED())
self._locked = True
return
except pywintypes.error as e:
if timeout == 0:
raise
# If the error is not that the file is already
# in use, raise.
if e[0] != _Win32Opener.FILE_IN_USE_ERROR:
raise
# We could not acquire the lock. Try again.
if (time.time() - start_time) >= timeout:
logger.warn('Could not lock %s in %s seconds' % (
self._filename, timeout))
if self._fh:
self._fh.close()
self._fh = open(self._filename, self._fallback_mode)
return
time.sleep(delay)
def open_and_lock(self, timeout, delay):
"""Open the file and lock it.
Args:
timeout: float, How long to try to lock for.
delay: float, How long to wait between retries
Raises:
AlreadyLockedException: if the lock is already acquired.
IOError: if the open fails.
CredentialsFileSymbolicLinkError: if the file is a symbolic
link.
"""
if self._locked:
raise AlreadyLockedException('File {0} is already locked'.format(
self._filename))
start_time = time.time()
validate_file(self._filename)
try:
self._fh = open(self._filename, self._mode)
except IOError as e:
# If we can't access with _mode, try _fallback_mode
# and don't lock.
if e.errno == errno.EACCES:
self._fh = open(self._filename, self._fallback_mode)
return
# We opened in _mode, try to lock the file.
while True:
try:
hfile = win32file._get_osfhandle(self._fh.fileno())
win32file.LockFileEx(hfile,
(win32con.LOCKFILE_FAIL_IMMEDIATELY
| win32con.LOCKFILE_EXCLUSIVE_LOCK), 0,
-0x10000, pywintypes.OVERLAPPED())
self._locked = True
return
except pywintypes.error as e:
if timeout == 0:
raise
# If the error is not that the file is already
# in use, raise.
if e[0] != _Win32Opener.FILE_IN_USE_ERROR:
raise
# We could not acquire the lock. Try again.
if (time.time() - start_time) >= timeout:
logger.warn('Could not lock %s in %s seconds',
self._filename, timeout)
if self._fh:
self._fh.close()
self._fh = open(self._filename, self._fallback_mode)
return
time.sleep(delay)
def open_and_lock(self, timeout, delay):
"""Open the file and lock it.
Args:
timeout: float, How long to try to lock for.
delay: float, How long to wait between retries
Raises:
AlreadyLockedException: if the lock is already acquired.
IOError: if the open fails.
CredentialsFileSymbolicLinkError: if the file is a symbolic
link.
"""
if self._locked:
raise AlreadyLockedException('File %s is already locked' %
self._filename)
start_time = time.time()
validate_file(self._filename)
try:
self._fh = open(self._filename, self._mode)
except IOError as e:
# If we can't access with _mode, try _fallback_mode and
# don't lock.
if e.errno in (errno.EPERM, errno.EACCES):
self._fh = open(self._filename, self._fallback_mode)
return
# We opened in _mode, try to lock the file.
while True:
try:
fcntl.lockf(self._fh.fileno(), fcntl.LOCK_EX)
self._locked = True
return
except IOError as e:
# If not retrying, then just pass on the error.
if timeout == 0:
raise
if e.errno != errno.EACCES:
raise
# We could not acquire the lock. Try again.
if (time.time() - start_time) >= timeout:
logger.warn('Could not lock %s in %s seconds',
self._filename, timeout)
if self._fh:
self._fh.close()
self._fh = open(self._filename, self._fallback_mode)
return
time.sleep(delay)