class Chuck(object):
def __init__(self):
self.meggage_parser = ChunkMsg()
self.clean()
def clean(self):
self.parse_error = ""
def data_from_raw(self, data):
self.clean()
offset = 0
if not data:
self.self.parse_error += 'No chunk data'
return (False, 0)
flags_with_size, size_seq = struct.unpack_from("!BB", data, offset=offset)
offset += 2
flags = (flags_with_size>>6) & 0x03
size = ((flags_with_size&0x3F)<<4) | (size_seq&0b1111)
sequence = -1
if flags & MSGFLAG_VITAL:
seq = struct.unpack_from("!B", data, offset=offset)[0]
offset += 1
sequence = ((size_seq&0xC0)<<2) | seq
if len(data[offset:]) < size:
self.parse_error += 'ERROR! data < chuck_size\n'
self.parse_error += bin(flags_with_size)+ ' ' + bin(size_seq) + '<--size' + str(len(data[offset:])) + ' '+ bin(len(data[offset:])) + ' ' + str(sequence)
return (False, 0)
raw_data = data[offset:size+offset]
offset += size
chunk_data = {
'flags': flags,
'sequence': sequence,
# 'raw_data': raw_data,
'message': self.meggage_parser.load_from_raw(raw_data),
}
return (chunk_data, offset)
def build_raw_from_data(self, data):
self.clean()
flags = data['flags']
sequence = data['sequence']
# raw_data = data['raw_data']
raw_data = self.meggage_parser.build_raw_from_data(data['message'])
size = len(raw_data)
flags_with_size = ((flags&0x03)<<6) | ((size>>4)&0x3F)
size_seq = size & 0b1111
if flags & MSGFLAG_VITAL:
size_seq |= (sequence>>2)&0xC0
sequence = sequence&0xFF
header = struct.pack('!BBB', flags_with_size, size_seq, sequence)
else:
header = struct.pack('!BB', flags_with_size, size_seq)
return header+raw_data
def __init__(self):
self.meggage_parser = ChunkMsg()
self.clean()
