id	summary	reporter	owner	description	type	status	priority	milestone	component	version	severity	resolution	keywords	cc	difficulty	ghcversion	platform
338	use of HTTP needs overhauling	duncan		"We're not using HTTP the protocol or HTTP the package effectively

 * As I understand it, the HTTP lib buffers the entire http download in memory rather than returning it lazily, so we cannot stream it to disk. It's also all done using `String`.
 * We do not check (and nor does the HTTP lib) for truncated downloads. That is where the `Content-Length` header differs from the actual length.
 * We do not cache the ETag so we cannot optimise the case of re-downloading an unchanged index.
 * We make a new tcp connection for each download, rather than doing all downloads within a single browse session.
 * We are not doing downloads concurrent with package builds.

We should probably use a dedicated thread for downloads. It should serialise downloads and use a single browse session. Even without support for streaming the body directly we could at least write files atomically, checking length header. And also cache the ETag."	enhancement	closed	normal		cabal-install tool	1.2.3.0	normal	duplicate			normal	6.8.2