Creating a streaming (audio) response

It took me a little while to get this right so I wonder if you can see this as an addition to the docs somewhere? In my case I am loading audio as bytes from a database and I create a response in the following way:

from io import BytesIO

from starlette.endpoints import HTTPEndpoint
from starlette.requests import Request
from starlette.responses import StreamingResponse


class AudioEndpoint(HTTPEndpoint):
    async def get(self, request: Request) -> StreamingResponse:
        """Return an mp3 audio stream."""
        # Load the content from the database.
        audio = ...
        headers = {
            "Content-Length": str(len(audio))
        }
        return StreamingResponse(
            self.stream_audio(record), media_type="audio/mpeg3",
            headers=headers
        )

    @staticmethod
    async def stream_audio(record: bytes, chunk_size: int = 4096):
        with BytesIO(record) as stream:
            data = stream.read(chunk_size)
            while data:
                yield data
                data = stream.read(chunk_size)

Hints for improvements are, of course, welcome 😉

[Midnighter]

I think I was struggling a bit with the decision to send everything as one big chunk or whether to stream it. That’s not really Starlette specific, though, so probably current docs are fine and maybe someone is happy to find this here on GitHub.

[tomchristie]

Ah sure. No, don’t do that. 😃