import sys
import struct

class PulseWire:
    def __init__(self):
        ...

    def on_raw_engine_request(self, data: bytes):
        ...

    def send_raw(self, data: bytes):
        sys.stdout.buffer.write(len(data).to_bytes(8, "little"))
        sys.stdout.buffer.write(data)
        sys.stdout.flush()

    def start(self):
        while True:
            len_buf = sys.stdin.buffer.read(struct.calcsize("P"))

            if len(len_buf) == 0:
                return None

            length = int.from_bytes(len_buf, "little")

            if length == 0:
                return None

            buffer = sys.stdin.buffer.read(length)

            if len(buffer) != length:
                raise EOFError("Unexpected EOF while reading payload")

            self.on_raw_engine_request(buffer)