Before this fix, download threads would fill up the buffer and then
timeout even though data was still being read from them. If the client
was streaming slower than network speed this caused the downloader to
stop and be restarted continuously. This caused more potential for
skips in the download and unecessary network transactions.
This patch fixes that behaviour - as long as a downloader is being
read from more often than once every 5 seconds, it won't timeout.
This was done by:
- kicking the downloader whenever ensureDownloader is called
- making the downloader loop if it has already downloaded past the maxOffset
- making setRange() always kick the downloader
This is preparation for getting the Accounting to check the context,
buf first we need to get it in place. Since this is one of those
changes that makes lots of noise, this is in a seperate commit.
This was caused by the signal to stop buffering being ignored when
there was no buffer!
This is fixed by explicitly checking for no buffering and stopping.
