py-libp2p/libp2p/stream_muxer/mplex/utils.py
2019-08-05 10:45:46 +08:00

45 lines
927 B
Python

import asyncio
import struct
def encode_uvarint(number):
"""Pack `number` into varint bytes"""
buf = b""
while True:
towrite = number & 0x7F
number >>= 7
if number:
buf += bytes((towrite | 0x80,))
else:
buf += bytes((towrite,))
break
return buf
def decode_uvarint(buff, index):
shift = 0
result = 0
while True:
i = buff[index]
result |= (i & 0x7F) << shift
shift += 7
if not i & 0x80:
break
index += 1
return result, index + 1
async def decode_uvarint_from_stream(reader, timeout):
shift = 0
result = 0
while True:
byte = await asyncio.wait_for(reader.read(1), timeout=timeout)
i = struct.unpack(">H", b"\x00" + byte)[0]
result |= (i & 0x7F) << shift
shift += 7
if not i & 0x80:
break
return result