rpc: implement stdio client

rpc/client.go

@@ -33,6 +33,7 @@ import (
 	"time"
 
 	"github.com/ethereum/go-ethereum/log"
+	"os"
 )
 
 var (
@@ -171,6 +172,8 @@ func DialContext(ctx context.Context, rawurl string) (*Client, error) {
 		return DialHTTP(rawurl)
 	case "ws", "wss":
 		return DialWebsocket(ctx, rawurl, "")
+	case "stdio":
+		return DialStdIO(ctx)
 	case "":
 		return DialIPC(ctx, rawurl)
 	default:
@@ -178,13 +181,51 @@ func DialContext(ctx context.Context, rawurl string) (*Client, error) {
 	}
 }
 
+type StdIOConn struct{}
+
+func (io StdIOConn) Read(b []byte) (n int, err error) {
+	return os.Stdin.Read(b)
+}
+
+func (io StdIOConn) Write(b []byte) (n int, err error) {
+	return os.Stdout.Write(b)
+}
+
+func (io StdIOConn) Close() error {
+	return nil
+}
+
+func (io StdIOConn) LocalAddr() net.Addr {
+	return &net.UnixAddr{Name: "stdio", Net: "stdio"}
+}
+
+func (io StdIOConn) RemoteAddr() net.Addr {
+	return &net.UnixAddr{Name: "stdio", Net: "stdio"}
+}
+
+func (io StdIOConn) SetDeadline(t time.Time) error {
+	return &net.OpError{Op: "set", Net: "stdio", Source: nil, Addr: nil, Err: errors.New("deadline not supported")}
+}
+
+func (io StdIOConn) SetReadDeadline(t time.Time) error {
+	return &net.OpError{Op: "set", Net: "stdio", Source: nil, Addr: nil, Err: errors.New("deadline not supported")}
+}
+
+func (io StdIOConn) SetWriteDeadline(t time.Time) error {
+	return &net.OpError{Op: "set", Net: "stdio", Source: nil, Addr: nil, Err: errors.New("deadline not supported")}
+}
+func DialStdIO(ctx context.Context) (*Client, error) {
+	return newClient(ctx, func(_ context.Context) (net.Conn, error) {
+		return StdIOConn{}, nil
+	})
+}
+
 func newClient(initctx context.Context, connectFunc func(context.Context) (net.Conn, error)) (*Client, error) {
 	conn, err := connectFunc(initctx)
 	if err != nil {
 		return nil, err
 	}
 	_, isHTTP := conn.(*httpConn)
-
 	c := &Client{
 		writeConn:   conn,
 		isHTTP:      isHTTP,
@@ -524,13 +565,13 @@ func (c *Client) dispatch(conn net.Conn) {
 			}
 
 		case err := <-c.readErr:
-			log.Debug(fmt.Sprintf("<-readErr: %v", err))
+			log.Debug("<-readErr", "err", err)
 			c.closeRequestOps(err)
 			conn.Close()
 			reading = false
 
 		case newconn := <-c.reconnected:
-			log.Debug(fmt.Sprintf("<-reconnected: (reading=%t) %v", reading, conn.RemoteAddr()))
+			log.Debug("<-reconnected", "reading", reading, "remote", conn.RemoteAddr())
 			if reading {
 				// Wait for the previous read loop to exit. This is a rare case.
 				conn.Close()
@@ -587,7 +628,7 @@ func (c *Client) closeRequestOps(err error) {
 
 func (c *Client) handleNotification(msg *jsonrpcMessage) {
 	if !strings.HasSuffix(msg.Method, notificationMethodSuffix) {
-		log.Debug(fmt.Sprint("dropping non-subscription message: ", msg))
+		log.Debug("dropping non-subscription message", "msg", msg)
 		return
 	}
 	var subResult struct {
@@ -595,7 +636,7 @@ func (c *Client) handleNotification(msg *jsonrpcMessage) {
 		Result json.RawMessage `json:"result"`
 	}
 	if err := json.Unmarshal(msg.Params, &subResult); err != nil {
-		log.Debug(fmt.Sprint("dropping invalid subscription message: ", msg))
+		log.Debug("dropping invalid subscription message", "msg", msg)
 		return
 	}
 	if c.subs[subResult.ID] != nil {
@@ -606,7 +647,7 @@ func (c *Client) handleNotification(msg *jsonrpcMessage) {
 func (c *Client) handleResponse(msg *jsonrpcMessage) {
 	op := c.respWait[string(msg.ID)]
 	if op == nil {
-		log.Debug(fmt.Sprintf("unsolicited response %v", msg))
+		log.Debug("unsolicited response", "msg", msg)
 		return
 	}
 	delete(c.respWait, string(msg.ID))