rpc: add new client, use it everywhere

The new client implementation supports concurrent requests,
subscriptions and replaces the various ad hoc RPC clients
throughout go-ethereum.

rpc/inproc.go

@@ -17,45 +17,18 @@
 package rpc
 
 import (
-	"encoding/json"
-	"io"
 	"net"
+
+	"golang.org/x/net/context"
 )
 
-// inProcClient is an in-process buffer stream attached to an RPC server.
-type inProcClient struct {
-	server *Server
-	cl     io.Closer
-	enc    *json.Encoder
-	dec    *json.Decoder
-}
-
-// Close tears down the request channel of the in-proc client.
-func (c *inProcClient) Close() {
-	c.cl.Close()
-}
-
-// NewInProcRPCClient creates an in-process buffer stream attachment to a given
-// RPC server.
-func NewInProcRPCClient(handler *Server) Client {
-	p1, p2 := net.Pipe()
-	go handler.ServeCodec(NewJSONCodec(p1), OptionMethodInvocation|OptionSubscriptions)
-	return &inProcClient{handler, p2, json.NewEncoder(p2), json.NewDecoder(p2)}
-}
-
-// Send marshals a message into a json format and injects in into the client
-// request channel.
-func (c *inProcClient) Send(msg interface{}) error {
-	return c.enc.Encode(msg)
-}
-
-// Recv reads a message from the response channel and tries to parse it into the
-// given msg interface.
-func (c *inProcClient) Recv(msg interface{}) error {
-	return c.dec.Decode(msg)
-}
-
-// Returns the collection of modules the RPC server offers.
-func (c *inProcClient) SupportedModules() (map[string]string, error) {
-	return SupportedModules(c)
+// NewInProcClient attaches an in-process connection to the given RPC server.
+func DialInProc(handler *Server) *Client {
+	initctx := context.Background()
+	c, _ := newClient(initctx, func(context.Context) (net.Conn, error) {
+		p1, p2 := net.Pipe()
+		go handler.ServeCodec(NewJSONCodec(p1), OptionMethodInvocation|OptionSubscriptions)
+		return p2, nil
+	})
+	return c
 }