ActualConnection: wrap BufReader around TcpStream

[astro]

Hi

I am just starting with Rust, and tried to receive messages with this library's experimental Pubsub support. The parser reads byte by byte, performing a lot of syscalls. What's your opinion on using BufReader to reduce the performance impact?

Safety not guaranteed. It still fails for me sometimes with Invalid byte in response

[astro]

It still fails for me sometimes with Invalid byte in response

Scratch that. redis kept disconnecting me because the network in between couldn't keep up.

[mitsuhiko]

The reason I did not use buf reader is because it did not seem like a good idea to read past what the responses indicate is safe to read. But I pulled your changes from #63 in.

[astro]

Are you concerned about blocking behaviour? I believe if not enough data is available the read from BufStream will return with what's available just like TcpStream.

In my case that's not relevant because all I'm doing with redis is receiving pubsub notifications at a high rate. This change lowers my CPU usage by a lot.

[xitep]

today i gave redis-rs a try and while i generally like its api i wondered why it is that slow. after some basic profiling i basically came to the same conclusion as @astro. reading the tcp stream char-by-char is definitely a show-stopper (for me) :( at least astro's patch gives my program a considerable speed-up.

[astro]

FYI: my workload changed from just PubSub to interactive commands as well. I'm running with this patch and it's working fine.

[mitsuhiko]

Let's see how this goes.