read message func addition

Signed-off-by: sreenidhi <sreenidhi.dr@ibm.com>

Author: sreenidhidrIBM

token/services/ttx/session.go

@@ -9,6 +9,7 @@ package ttx
 import (
 	"context"
 	"encoding/base64"
+	"time"
 
 	"github.com/hyperledger-labs/fabric-smart-client/platform/view/view"
 	"github.com/pkg/errors"
@@ -127,3 +128,23 @@ func (s *localSession) Receive() <-chan *view.Message {
 func (s *localSession) Close() {
 	s.info.Closed = true
 }
+
+func ReadMessage(session view.Session, timeout time.Duration) ([]byte, error) {
+	timer := time.NewTimer(timeout)
+	defer timer.Stop()
+
+	ch := session.Receive()
+	select {
+	case msg := <-ch:
+		if msg == nil {
+			return nil, errors.New("received nil tx")
+		}
+		if msg.Status == view.ERROR {
+			return nil, errors.New(string(msg.Payload))
+		}
+		return msg.Payload, nil
+	case <-timer.C:
+		err := errors.New("timeout reached")
+		return nil, err
+	}
+}