From e19c10a2191ccdae1154d7775d41dec59699d78c Mon Sep 17 00:00:00 2001
From: giongto35 <giongto35@yahoo.com>
Date: Sun, 21 Apr 2019 18:11:53 +0800
Subject: [PATCH] Only maintains heartbeat from server to overlord

---
 main.go     |  5 ++++-
 overlord.go |  1 +
 ws.go       | 16 +++++++++++++---
 3 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/main.go b/main.go
index 1114b99a..37e54a75 100644
--- a/main.go
+++ b/main.go
@@ -73,12 +73,13 @@ func main() {
 	}
 	if len(os.Args) >= 3 {
 		if os.Args[2] == "overlord" {
+			fmt.Println("Running as overlord ")
 			IsOverlord = true
 		} else {
+			fmt.Println("Running as slave ")
 			// If the third arg is not overlord, it is path to overlord
 			overlordHost = os.Args[2]
 		}
-		fmt.Println("Running as overlord ")
 	}
 	if len(os.Args) >= 4 {
 		port = os.Args[3]
@@ -536,6 +537,8 @@ func NewOverlordClient() *Client {
 			return req
 		},
 	)
+	// heartbeat to keep pinging overlord. We not ping from server to browser, so we don't call heartbeat in browserClient
+	go oclient.heartbeat()
 	go oclient.listen()
 
 	return oclient
diff --git a/overlord.go b/overlord.go
index 06c90341..e7d2fdf0 100644
--- a/overlord.go
+++ b/overlord.go
@@ -62,6 +62,7 @@ func wso(w http.ResponseWriter, r *http.Request) {
 	})
 
 	client.receive("getRoom", func(resp WSPacket) WSPacket {
+		log.Println("Received a getroom request")
 		return WSPacket{
 			ID:   "getRoom",
 			Data: roomToServer[resp.Data],
diff --git a/ws.go b/ws.go
index 035b4d37..f9d8d4e7 100644
--- a/ws.go
+++ b/ws.go
@@ -96,6 +96,16 @@ func (c *Client) syncSend(request WSPacket) (response WSPacket) {
 	return <-res
 }
 
+// heartbeat maintains connection to server
+func (c *Client) heartbeat() {
+	// send heartbeat every 1s
+	timer := time.Tick(time.Second)
+
+	for range timer {
+		c.send(WSPacket{ID: "heartbeat"}, nil)
+	}
+}
+
 func (c *Client) listen() {
 	for {
 		log.Println("Waiting for message")
@@ -106,20 +116,20 @@ func (c *Client) listen() {
 		}
 		wspacket := WSPacket{}
 		err = json.Unmarshal(rawMsg, &wspacket)
-		if err != nil {
+		if err != nil || wspacket.ID == "heartbeat" {
 			continue
 		}
 
 		// Check if some async send is waiting for the response based on packetID
 		if callback, ok := c.sendCallback[wspacket.PacketID]; ok {
-			callback(wspacket)
+			go callback(wspacket)
 			delete(c.sendCallback, wspacket.PacketID)
 			// Skip receiveCallback to avoid duplication
 			continue
 		}
 		// Check if some receiver with the ID is registered
 		if callback, ok := c.recvCallback[wspacket.ID]; ok {
-			callback(wspacket)
+			go callback(wspacket)
 		}
 	}
 }