connections.py 文件源码

def read_length_coded_binary(self):
    """Read a 'Length Coded Binary' number from the data buffer.

    Length coded numbers can be anywhere from 1 to 9 bytes depending
    on the value of the first byte.
    """
    c = byte2int(self.read(1))
    if c == NULL_COLUMN:
      return None
    if c < UNSIGNED_CHAR_COLUMN:
      return c
    elif c == UNSIGNED_SHORT_COLUMN:
      return unpack_uint16(self.read(UNSIGNED_SHORT_LENGTH))
    elif c == UNSIGNED_INT24_COLUMN:
      return unpack_int24(self.read(UNSIGNED_INT24_LENGTH))
    elif c == UNSIGNED_INT64_COLUMN:
      # TODO: what was 'longlong'?  confirm it wasn't used?
      return unpack_int64(self.read(UNSIGNED_INT64_LENGTH))