http: add NewProxyClientConn

This just returns a ClientConn suitable for writing
proxy requests.  To be used in Transport.

R=rsc, petar-m
CC=golang-dev
https://golang.org/cl/4290052

diff --git a/src/pkg/http/persist.go b/src/pkg/http/persist.go
index 53efd7c8c6a9979f56aac428d58ec19083c9be86..a8285c894a46483e72facbe568f59156856a4662 100644 (file)
--- a/src/pkg/http/persist.go
+++ b/src/pkg/http/persist.go
@@ -211,7 +211,8 @@ type ClientConn struct {
        nread, nwritten int
        pipereq         map[*Request]uint
 
-       pipe textproto.Pipeline
+       pipe     textproto.Pipeline
+       writeReq func(*Request, io.Writer) os.Error
 }
 
 // NewClientConn returns a new ClientConn reading and writing c.  If r is not
@@ -220,7 +221,20 @@ func NewClientConn(c net.Conn, r *bufio.Reader) *ClientConn {
        if r == nil {
                r = bufio.NewReader(c)
        }
-       return &ClientConn{c: c, r: r, pipereq: make(map[*Request]uint)}
+       return &ClientConn{
+               c:        c,
+               r:        r,
+               pipereq:  make(map[*Request]uint),
+               writeReq: (*Request).Write,
+       }
+}
+
+// NewProxyClientConn works like NewClientConn but writes Requests
+// using Request's WriteProxy method.
+func NewProxyClientConn(c net.Conn, r *bufio.Reader) *ClientConn {
+       cc := NewClientConn(c, r)
+       cc.writeReq = (*Request).WriteProxy
+       return cc
 }
 
 // Close detaches the ClientConn and returns the underlying connection as well
@@ -281,7 +295,7 @@ func (cc *ClientConn) Write(req *Request) (err os.Error) {
        }
        cc.lk.Unlock()
 
-       err = req.Write(c)
+       err = cc.writeReq(req, c)
        cc.lk.Lock()
        defer cc.lk.Unlock()
        if err != nil {