bazarr/libs/engineio/payload.py
Louis Vézina 83c95cc77d WIP
2020-01-29 20:07:26 -05:00

81 lines
3 KiB
Python

import six
from . import packet
from six.moves import urllib
class Payload(object):
"""Engine.IO payload."""
max_decode_packets = 16
def __init__(self, packets=None, encoded_payload=None):
self.packets = packets or []
if encoded_payload is not None:
self.decode(encoded_payload)
def encode(self, b64=False, jsonp_index=None):
"""Encode the payload for transmission."""
encoded_payload = b''
for pkt in self.packets:
encoded_packet = pkt.encode(b64=b64)
packet_len = len(encoded_packet)
if b64:
encoded_payload += str(packet_len).encode('utf-8') + b':' + \
encoded_packet
else:
binary_len = b''
while packet_len != 0:
binary_len = six.int2byte(packet_len % 10) + binary_len
packet_len = int(packet_len / 10)
if not pkt.binary:
encoded_payload += b'\0'
else:
encoded_payload += b'\1'
encoded_payload += binary_len + b'\xff' + encoded_packet
if jsonp_index is not None:
encoded_payload = b'___eio[' + \
str(jsonp_index).encode() + \
b']("' + \
encoded_payload.replace(b'"', b'\\"') + \
b'");'
return encoded_payload
def decode(self, encoded_payload):
"""Decode a transmitted payload."""
self.packets = []
if len(encoded_payload) == 0:
return
# JSONP POST payload starts with 'd='
if encoded_payload.startswith(b'd='):
encoded_payload = urllib.parse.parse_qs(
encoded_payload)[b'd'][0]
i = 0
if six.byte2int(encoded_payload[0:1]) <= 1:
# binary encoding
while i < len(encoded_payload):
if len(self.packets) >= self.max_decode_packets:
raise ValueError('Too many packets in payload')
packet_len = 0
i += 1
while six.byte2int(encoded_payload[i:i + 1]) != 255:
packet_len = packet_len * 10 + six.byte2int(
encoded_payload[i:i + 1])
i += 1
self.packets.append(packet.Packet(
encoded_packet=encoded_payload[i + 1:i + 1 + packet_len]))
i += packet_len + 1
else:
# assume text encoding
encoded_payload = encoded_payload.decode('utf-8')
while i < len(encoded_payload):
if len(self.packets) >= self.max_decode_packets:
raise ValueError('Too many packets in payload')
j = encoded_payload.find(':', i)
packet_len = int(encoded_payload[i:j])
pkt = encoded_payload[j + 1:j + 1 + packet_len]
self.packets.append(packet.Packet(encoded_packet=pkt))
i = j + 1 + packet_len