def rewind(self, position=0):
if position < 0 or position > len(self._data):
error_msg = "Invalid position to rewind cursor to: {}.".format(
position)
logger.error(error_msg)
raise Exception(error_msg)
self._position = position
async def start(self) -> bool:
# TODO PiDAL need authentication feature.
client = await TCPClient().connect("127.0.0.1", 3306,
timeout=60) # TODO
packet_header = await client.read_bytes(4)
bytes_to_read, packet_number = self._parse_header(packet_header)
if packet_number != 0:
logger.error("recv to xxx handshake packet_number is %s",
packet_number)
recv_data = await client.read_bytes(bytes_to_read)
await self.stream.write(packet_header + recv_data)
packet_header = await self.stream.read_bytes(4)
bytes_to_read, packet_number = self._parse_header(packet_header)
recv_data = await self.stream.read_bytes(bytes_to_read)
await client.write(packet_header + recv_data)
packet_header = await client.read_bytes(4)
bytes_to_read, packet_number = self._parse_header(packet_header)
recv_data = await client.read_bytes(bytes_to_read)
await self.stream.write(packet_header + recv_data)
p_reader = PacketBytesReader(recv_data)
if p_reader.is_ok_packet():
return True
return False
def advance(self, length):
new_position = self._position + length
if new_position < 0 or new_position > len(self._data):
error_msg = "Invalid advance amount ({}) for cursor. \
Position={}".format(length, new_position)
logger.error(error_msg)
raise Exception(error_msg)
self._position = new_position
def read(self, size) -> bytes:
result = self._data[self._position:(self._position + size)]
if len(result) != size:
error_msg = "Result length not requested length. \
Expected={}. Actual={}.\
Position: {}. Data Length: {}".format(
size, len(result), self._position, len(self._data))
logger.error(error_msg)
raise AssertionError(error_msg)
self._position += size
return result
def read_length_encoded_integer(self) -> int:
c = self.read_uint8()
if c < UNSIGNED_CHAR_COLUMN:
return c
elif c == UNSIGNED_SHORT_COLUMN:
return self.read_uint16()
elif c == UNSIGNED_INT24_COLUMN:
return self.read_uint24()
elif c == UNSIGNED_INT64_COLUMN:
return self.read_uint64()
logger.error("unknown length integer %s.", c)
raise Exception("unknown length integer {}.".format(c))