Remove default case (#341)

* Remove `default` case

* fix lint error: S1000: should use a simple channel send/receive instead of `select` with a single case (gosimple)

* (fix) Remove block comment and add a comment

p2p/peer.go

@@ -399,19 +399,8 @@ func createMConnection(
 			// because msgBytes is on socket receive buffer yet so reactor can read it concurrently
 			copied := make([]byte, len(msgBytes))
 			copy(copied, msgBytes)
-			select {
-			case ch <- &BufferedMsg{
-				ChID: chID,
-				Peer: p,
-				Msg:  copied}:
-			default:
-				// if the channel is full, we abandon this message
-				// Should check `config.Config.XxxBufSize`
-				p.Logger.Error("Lost the message since BaseReactor.recvMsgBuf is full",
-					"reactor", reactor,
-					"msgBytes.len", len(msgBytes), "msgBytes", fmt.Sprintf("%X", msgBytes))
-				p.metrics.NumAbandonedPeerMsgs.With(labels...).Add(1)
-			}
+			// if the channel is full, we are blocking a message until it can send into the channel
+			ch <- &BufferedMsg{ChID: chID, Peer: p, Msg: copied}
 		} else {
 			reactor.Receive(chID, p, msgBytes)
 		}