http: Check cancel flag more often

[unknownbrackets]

Would be better to use non-blocking sockets, but this code is working, so not planning to rewrite it right now.

This just makes us run select() on sockets before reading/writing to them. Before, we would try to write, and only timeout if we got data slowly. In a situation where the user loses signal, recv() will just block. In other places, we were using a timeout - but only checking at the end of the entire timeout.

Now, we check the cancel flag in small chunks of 0.25s waits. So if the user loses connectivity, it won't just wait and wait.

Actual behavior with a good connection should not be impacted.

-[Unknown]

[hrydgard]

Thanks!

Ideally we should probably switch to some trusted crossplatform all in one solution for http downloads, or use platform specific stuff like the Android Download Manager. But yeah, not now. And I don't know what that crossplatform solution would be...

I'm gonna test this on a few platforms, and then probably merge in to 1.10.2.

[hrydgard]

Somehow this seems to greatly improve download speed on both Windows and Android? Can't complain :)

Will try on Mac too and a couple of old Android devices, then merge if all goes well.

[unknownbrackets]

Interesting. It seemed faster to me too but I wasn't sure. It should process the buffer more efficiently but greatly is a bit unexpected.

-[Unknown]