py-libp2p/libp2p/stream_muxer/mplex/utils.py

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import asyncio
import struct
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from typing import Tuple
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from libp2p.typing import StreamReader
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def encode_uvarint(number: int) -> bytes:
"""Pack `number` into varint bytes"""
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buf = b""
while True:
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towrite = number & 0x7F
number >>= 7
if number:
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buf += bytes((towrite | 0x80,))
else:
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buf += bytes((towrite,))
break
return buf
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def decode_uvarint(buff: bytes, index: int) -> Tuple[int, int]:
shift = 0
result = 0
while True:
i = buff[index]
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result |= (i & 0x7F) << shift
shift += 7
if not i & 0x80:
break
index += 1
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return result, index + 1
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async def decode_uvarint_from_stream(reader: StreamReader, timeout: float) -> int:
shift = 0
result = 0
while True:
byte = await asyncio.wait_for(reader.read(1), timeout=timeout)
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i = struct.unpack(">H", b"\x00" + byte)[0]
result |= (i & 0x7F) << shift
shift += 7
if not i & 0x80:
break
return result