def write(self):
self.size = 14
chunk = self._format.pack(self.size, self.protocol_version,
self.profile_version, self.data_size,
self.data_type)
self.crc.value = compute_crc(chunk)
return chunk + self.crc.write()
def write(self):
self.size = 14
chunk = self._format.pack(self.size, self.protocol_version,
self.profile_version, self.data_size,
self.data_type)
self.crc.value = compute_crc(chunk)
return chunk + self.crc.write()
def read(self, chunk):
(self.size, self.protocol_version, self.profile_version,
self.data_size, self.data_type) = self._format.unpack(chunk[:12])
if len(chunk) == 14:
self.crc.read(chunk[12:])
if self.crc.value and not self.crc.check(chunk[:12]):
raise BodyFormatError(
"Invalid CRC %x, should be %x" %
(compute_crc(chunk[:12]), self.crc.value))
def read(self, chunk):
(
self.size, self.protocol_version, self.profile_version,
self.data_size, self.data_type
) = self._format.unpack(chunk[:12])
if len(chunk) == 14:
self.crc.read(chunk[12:])
if self.crc.value and not self.crc.check(chunk[:12]):
raise BodyFormatError("Invalid CRC %x, should be %x" % (
compute_crc(chunk[:12]), self.crc.value))
def body(self):
if not self._body:
self._fd.seek(self.header.size)
body = self._fd.read(self.header.data_size)
if len(body) != self.header.data_size:
raise BodyFormatError(
"Can't read %d bytes, read %d bytes instead" % (
self.header.data_size, len(body)))
header = "" if self.header.crc.value else self.header_chunk
if not self.crc.check(header + body):
raise BodyFormatError("Invalid CRC %x, should be %x" % (
compute_crc(body), self.crc.value))
self._body.read(body)
return self._body
def body(self):
if not self._body:
self._fd.seek(self.header.size)
body = self._fd.read(self.header.data_size)
if len(body) != self.header.data_size:
raise BodyFormatError(
"Can't read %d bytes, read %d bytes instead" %
(self.header.data_size, len(body)))
header = "" if self.header.crc.value else self.header_chunk
if not self.crc.check(header + body):
raise BodyFormatError("Invalid CRC %x, should be %x" %
(compute_crc(body), self.crc.value))
self._body.read(body)
return self._body
def _prepare(self):
chunk = self.body.write()
self.header.data_size = len(chunk)
self.crc.value = compute_crc(chunk)
return chunk
def _prepare(self):
chunk = self.body.write()
self.header.data_size = len(chunk)
self.crc.value = compute_crc(chunk)
return chunk
