Does an async stream pipe target need to drain the stream or can I exit early?

[ptr727]

I am using a pipe target and a stream to read from stdout.

Do I need to keep reading from the stream until done, or cancelled, or can I return early when I found the data I was looking for?
Stated differently, will the internal implementation keep draining the stream for me even if I exit, or will it starve if I don't keep reading until done?

E.g.

PipeTarget stdOutTarget = PipeTarget.Create(
                    async (stream, cancellationToken) =>
                    {
                        // Read the stream
                        Utf8JsonAsyncStreamReader jsonStreamReader = new(stream);
                        while (await jsonStreamReader.ReadAsync(cancellationToken))
                        {

[Tyrrrz]

You can return early, but then the pipe will be closed -- CliWrap will not finish draining the data for you, but the process will also not be able to write any more data either. This is exactly how PipeTarget.Null works, so the warning in the readme applies here:

https://github.com/Tyrrrz/CliWrap#:~:text=Warning%3A%20Using%20PipeTarget,Stream.Null).

Generally it should be fine, but whether the process will be able to complete successfully depends on the program you're running. You won't get a deadlock though.

[ptr727]

Ok, thx, so if I interpret that correctly; I either need to terminate process when I'm no longer interested in its output, or keep on reading until it is done writing or risk blocking output. It is easy enough to just drain the stream until done, I'll see if it is worth terminating the process early.

[Tyrrrz]

There is no risk blocking output with CliWrap's pipes (ever, by design). If you return early, you'll just close the pipe and the underlying process will have to decide if it's okay with that.

[ptr727]

Ok, I misunderstood "but the process will also not be able to write any more data either" to be blocking vs. up to the process. I'll test what happens if I just exit early.