Cost of cloning a stream

[davidbrochart]

Say you register a callback for sending to a stream, that will potentially be called a lot of times. The stream would need to be cloned, right?

def synchronous_callback(send_stream: MemoryObjectSendStream) -> None:
    cloned = send_stream.clone()
    with cloned:
        cloned.send_nowait('hello')

I was wondering if cloning is expensive in terms of CPU, or negligible?
Or maybe I should not use a context manager and thus not close the stream in the first place?

[agronholm]

The cost is negligible. Memory object streams are supposed to be closed eagerly when they're no longer needed.

[agronholm]

Oh, one more thing: You're not handling the case when the buffer is full.

[agronholm]

Now that I look more closely, why are you cloning the stream in the first place?

[davidbrochart]

Yes that was one question, I guess I shouldn't use the context manager then, and just send.

[agronholm]

Yup. But what will you do if the queue is full?

[davidbrochart]

I can catch the WouldBlock exception and react accordingly. Do you mean the context manager helps in that regard?