def write(self, data):
if self.closed:
raise ValueError('I/O operation on closed file')
if not self.allow_write:
raise vfs.PermissionError('file not opened for writing')
self._device.write_bytes(self._position, data)
self._position += len(data)
def read(self, size=None):
if self.closed:
raise ValueError('I/O operation on closed file')
if not self.allow_read:
raise vfs.PermissionError('file not opened for reading')
if size is None:
raise NotImplementError
else:
r = self._device.read_bytes(self._position, size)
self._position += len(r)
return r
def write(self, data):
self.check_closed()
if not self.allow_write:
raise vfs.PermissionError('file not opened for writing')
self._node._data = \
self._node._data[:self._position] \
+ chr(0) * (self._position - len(self._node._data)) \
+ data \
+ self._node._data[self._position+len(data):]
self._position += len(data)
return len(data)
def read(self, size=None):
self.check_closed()
if not self.allow_read:
raise vfs.PermissionError('file not opened for reading')
if size is not None:
r = self._node._data[self._position:self._position + size]
elif self._position:
r = self._node._data[self._position:]
else:
r = self._node._data
self._position += len(r)
return r
def write_bytes(self, first, count):
if not self.allow_write:
raise vfs.PermissionError('file not opened for writing')
return self._device.write_bytes(first, count)
def read_bytes(self, first, count):
if not self.allow_read:
raise vfs.PermissionError('file not opened for reading')
return self._device.read_bytes(first, count)