This patch adds a connection cache and keep-alive
support to Transport, which is used by the
HTTP client.
It's also structured such that it's easy to add
HTTP pipelining in the future.
R=rsc, petar-m, bradfitzwork, r
CC=golang-dev
https://golang.org/cl/4272045
Transport.Do -> RoundTripper.RoundTrip
This makes way for a subsequent CL to export the
currently private RoundTripper implementation
as struct Transport.
R=rsc, r
CC=golang-dev
https://golang.org/cl/4286043
Much yet to come, but this is a safe first step, introducing
an in-the-future configurable Client object (where policy for
cookies, auth, redirects will live) as well as introducing a
ClientTransport interface for sending requests.
The CL intentionally ignores everything around the creation
and configuration of Clients and merely ports/wraps the old
interfaces to/around Client/ClientTransport.
R=rsc, dsymonds, nigeltao, bradfitzwork
CC=golang-dev
https://golang.org/cl/4182086
