transports/websocket: Rewrite from scratch

Use github.com/sourcegraph/jsonrpc2 and github.com/gorilla/websocket.

The transport package should be more robust now. The code is much less
messy and it uses up-to-date packages.

The transport API is also changes. You can now pass multiple WebSocket
endpoint URLs and the auto-reconnect logic will use round-robin to
rotate between the URLs provided.

transports/websocket/errors.go

@@ -2,6 +2,4 @@ package websocket
 
 import "errors"
 
-var (
-	ErrClosing = errors.New("closing")
-)
+var ErrClosing = errors.New("closing")

transports/websocket/events.go

@@ -2,7 +2,6 @@ package websocket
 
 import (
 	"fmt"
-	"time"
 )
 
 // ConnectingEvent is emitted when a new connection is being established.
@@ -32,14 +31,3 @@ type DisconnectedEvent struct {
 func (e *DisconnectedEvent) String() string {
 	return fmt.Sprintf("DISCONNECTED [url=%v, err=%v]", e.URL, e.Err)
 }
-
-// DialTimeoutEvent is emitted when establishing a new connection times out.
-type DialTimeoutEvent struct {
-	URL     string
-	Err     error
-	Timeout time.Duration
-}
-
-func (e *DialTimeoutEvent) String() string {
-	return fmt.Sprintf("DIAL_TIMEOUT [url=%v, err=%v, timeout=%v]", e.URL, e.Err, e.Timeout)
-}

transports/websocket/object_stream.go

@@ -0,0 +1,36 @@
+package websocket
+
+import (
+	"time"
+
+	"github.com/gorilla/websocket"
+	jsonrpc2websocket "github.com/sourcegraph/jsonrpc2/websocket"
+)
+
+// ObjectStream implements jsonrpc2.ObjectStream that uses a WebSocket.
+// It extends jsonrpc2/websocket.ObjectStream with read/write timeouts.
+type ObjectStream struct {
+	conn   *websocket.Conn
+	stream jsonrpc2websocket.ObjectStream
+
+	writeTimeout time.Duration
+	readTimeout  time.Duration
+}
+
+func NewObjectStream(conn *websocket.Conn, writeTimeout, readTimeout time.Duration) *ObjectStream {
+	return &ObjectStream{conn, jsonrpc2websocket.NewObjectStream(conn), writeTimeout, readTimeout}
+}
+
+func (stream *ObjectStream) WriteObject(v interface{}) error {
+	stream.conn.SetWriteDeadline(time.Now().Add(stream.writeTimeout))
+	return stream.stream.WriteObject(v)
+}
+
+func (stream *ObjectStream) ReadObject(v interface{}) error {
+	stream.conn.SetReadDeadline(time.Now().Add(stream.readTimeout))
+	return stream.stream.ReadObject(v)
+}
+
+func (stream *ObjectStream) Close() error {
+	return stream.stream.Close()
+}