Function write_frame

relay/protocol.py:287–297

Write a framed message: 4-byte big-endian length + JSON payload

(writer: asyncio.StreamWriter, payload: dict[str, Any])

async def write_frame(writer: asyncio.StreamWriter, payload: dict[str, Any]) -> None:
    """Write a framed message: 4-byte big-endian length + JSON payload"""
    payload_bytes = json.dumps(payload, ensure_ascii=False).encode("utf-8")
    length = len(payload_bytes)

    if length > MAX_PAYLOAD_BYTES:
        raise ValueError(f"Payload too large: {length} > {MAX_PAYLOAD_BYTES}")

    header = struct.pack(">I", length)  # 4-byte big-endian unsigned int
    writer.write(header + payload_bytes)
    await writer.drain()


async def read_frame(reader: asyncio.StreamReader) -> dict[str, Any]: