From 78745551c077bf54151202138c2629f288769561 Mon Sep 17 00:00:00 2001
From: Determinant <tederminant@gmail.com>
Date: Tue, 15 Sep 2020 23:55:34 -0400
Subject: WIP: geth-tavum

---
 rpc/websocket.go | 105 +++++++++++++++++++++++++++++++++++++++++++------------
 1 file changed, 82 insertions(+), 23 deletions(-)

(limited to 'rpc/websocket.go')

diff --git a/rpc/websocket.go b/rpc/websocket.go
index d87e8a5..a716383 100644
--- a/rpc/websocket.go
+++ b/rpc/websocket.go
@@ -25,26 +25,22 @@ import (
 	"os"
 	"strings"
 	"sync"
+	"time"
 
 	mapset "github.com/deckarep/golang-set"
-	"github.com/ava-labs/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/log"
 	"github.com/gorilla/websocket"
 )
 
 const (
-	wsReadBuffer  = 1024
-	wsWriteBuffer = 1024
+	wsReadBuffer       = 1024
+	wsWriteBuffer      = 1024
+	wsPingInterval     = 60 * time.Second
+	wsPingWriteTimeout = 5 * time.Second
 )
 
 var wsBufferPool = new(sync.Pool)
 
-// NewWSServer creates a new websocket RPC server around an API provider.
-//
-// Deprecated: use Server.WebsocketHandler
-func NewWSServer(allowedOrigins []string, srv *Server) *http.Server {
-	return &http.Server{Handler: srv.WebsocketHandler(allowedOrigins)}
-}
-
 // WebsocketHandler returns a handler that serves JSON-RPC to WebSocket connections.
 //
 // allowedOrigins should be a comma-separated list of allowed origin URLs.
@@ -63,7 +59,7 @@ func (s *Server) WebsocketHandler(allowedOrigins []string) http.Handler {
 			return
 		}
 		codec := newWebsocketCodec(conn)
-		s.ServeCodec(codec, OptionMethodInvocation|OptionSubscriptions)
+		s.ServeCodec(codec, 0)
 	})
 }
 
@@ -124,21 +120,13 @@ func (e wsHandshakeError) Error() string {
 	return s
 }
 
-// DialWebsocket creates a new RPC client that communicates with a JSON-RPC server
-// that is listening on the given endpoint.
-//
-// The context is used for the initial connection establishment. It does not
-// affect subsequent interactions with the client.
-func DialWebsocket(ctx context.Context, endpoint, origin string) (*Client, error) {
+// DialWebsocketWithDialer creates a new RPC client that communicates with a JSON-RPC server
+// that is listening on the given endpoint using the provided dialer.
+func DialWebsocketWithDialer(ctx context.Context, endpoint, origin string, dialer websocket.Dialer) (*Client, error) {
 	endpoint, header, err := wsClientHeaders(endpoint, origin)
 	if err != nil {
 		return nil, err
 	}
-	dialer := websocket.Dialer{
-		ReadBufferSize:  wsReadBuffer,
-		WriteBufferSize: wsWriteBuffer,
-		WriteBufferPool: wsBufferPool,
-	}
 	return newClient(ctx, func(ctx context.Context) (ServerCodec, error) {
 		conn, resp, err := dialer.DialContext(ctx, endpoint, header)
 		if err != nil {
@@ -152,6 +140,20 @@ func DialWebsocket(ctx context.Context, endpoint, origin string) (*Client, error
 	})
 }
 
+// DialWebsocket creates a new RPC client that communicates with a JSON-RPC server
+// that is listening on the given endpoint.
+//
+// The context is used for the initial connection establishment. It does not
+// affect subsequent interactions with the client.
+func DialWebsocket(ctx context.Context, endpoint, origin string) (*Client, error) {
+	dialer := websocket.Dialer{
+		ReadBufferSize:  wsReadBuffer,
+		WriteBufferSize: wsWriteBuffer,
+		WriteBufferPool: wsBufferPool,
+	}
+	return DialWebsocketWithDialer(ctx, endpoint, origin, dialer)
+}
+
 func wsClientHeaders(endpoint, origin string) (string, http.Header, error) {
 	endpointURL, err := url.Parse(endpoint)
 	if err != nil {
@@ -169,7 +171,64 @@ func wsClientHeaders(endpoint, origin string) (string, http.Header, error) {
 	return endpointURL.String(), header, nil
 }
 
+type websocketCodec struct {
+	*jsonCodec
+	conn *websocket.Conn
+
+	wg        sync.WaitGroup
+	pingReset chan struct{}
+}
+
 func newWebsocketCodec(conn *websocket.Conn) ServerCodec {
 	conn.SetReadLimit(maxRequestContentLength)
-	return newCodec(conn, conn.WriteJSON, conn.ReadJSON)
+	wc := &websocketCodec{
+		jsonCodec: NewFuncCodec(conn, conn.WriteJSON, conn.ReadJSON).(*jsonCodec),
+		conn:      conn,
+		pingReset: make(chan struct{}, 1),
+	}
+	wc.wg.Add(1)
+	go wc.pingLoop()
+	return wc
+}
+
+func (wc *websocketCodec) close() {
+	wc.jsonCodec.close()
+	wc.wg.Wait()
+}
+
+func (wc *websocketCodec) writeJSON(ctx context.Context, v interface{}) error {
+	err := wc.jsonCodec.writeJSON(ctx, v)
+	if err == nil {
+		// Notify pingLoop to delay the next idle ping.
+		select {
+		case wc.pingReset <- struct{}{}:
+		default:
+		}
+	}
+	return err
+}
+
+// pingLoop sends periodic ping frames when the connection is idle.
+func (wc *websocketCodec) pingLoop() {
+	var timer = time.NewTimer(wsPingInterval)
+	defer wc.wg.Done()
+	defer timer.Stop()
+
+	for {
+		select {
+		case <-wc.closed():
+			return
+		case <-wc.pingReset:
+			if !timer.Stop() {
+				<-timer.C
+			}
+			timer.Reset(wsPingInterval)
+		case <-timer.C:
+			wc.jsonCodec.encMu.Lock()
+			wc.conn.SetWriteDeadline(time.Now().Add(wsPingWriteTimeout))
+			wc.conn.WriteMessage(websocket.PingMessage, nil)
+			wc.jsonCodec.encMu.Unlock()
+			timer.Reset(wsPingInterval)
+		}
+	}
 }
-- 
cgit v1.2.3