Match best worker based on latency + Experiment with Singapore Host (#60)

* Add echo endpoint

* Fix async

* Use latency map

* Only start webRTC after worker match

* Experiment with Singapore server

* Update comments

README.md

@@ -1,6 +1,6 @@
 # Klog, Web-based Cloud Gaming Service
 - **US West (San Francisco)**: [http://usw.cloud.webgame2d.com](http://usw.cloud.webgame2d.com) - **US East(New York)**: [http://use.cloud.webgame2d.com](http://use.cloud.webgame2d.com)  
-- **Singapore**: [http://sg.cloud.webgame2d.com](http://sg.cloud.webgame2d.com) - **Europe (London)**: [http://eu.cloud.webgame2d.com](http://eu.cloud.webgame2d.com)
+- **Singapore**: [http://cloud.webgame2d.com](http://sg.cloud.webgame2d.com) - **Europe (London)**: [http://eu.cloud.webgame2d.com](http://eu.cloud.webgame2d.com)
 
 - [**Game Instruction**](document/instruction/)
 For the best gaming experience, please select the closest region to you.   

cmd/main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"flag"
+	"fmt"
 	"log"
 	"math/rand"
 	"net"
@@ -77,6 +78,12 @@ func initializeWorker() {
 			http.Handle("/metrics", promhttp.Handler())
 		}
 
+		// echo endpoint is where user will request to test latency
+		http.HandleFunc("/echo", func(w http.ResponseWriter, r *http.Request) {
+			w.Header().Set("Access-Control-Allow-Origin", "*")
+			fmt.Fprintf(w, "echo")
+		})
+
 		http.ListenAndServe(":"+strconv.Itoa(port), nil)
 	}
 }

cws/cws.go

@@ -159,6 +159,7 @@ func (c *Client) Listen() {
 		err = json.Unmarshal(rawMsg, &wspacket)
 
 		if err != nil {
+			log.Println("Warn: error decoding", rawMsg)
 			continue
 		}
 

overlord/handlers.go

@@ -1,6 +1,7 @@
 package overlord
 
 import (
+	"encoding/json"
 	"errors"
 	"fmt"
 	"html/template"
@@ -8,7 +9,6 @@ import (
 	"math"
 	"math/rand"
 	"net/http"
-	"strconv"
 	"strings"
 
 	"github.com/giongto35/cloud-game/config"
@@ -232,13 +232,18 @@ func (o *Server) getLatencyMapFromBrowser(client *BrowserClient) map[*WorkerClie
 		ID:   "checkLatency",
 		Data: strings.Join(addressList, ","),
 	})
-	log.Println("Received latency list:", data.Data)
-	latencies := strings.Split(data.Data, ",")
-	log.Println("Received latency list:", latencies)
 
-	for i, workerClient := range workersList {
-		il, _ := strconv.Atoi(latencies[i])
-		latencyMap[workerClient] = int64(il)
+	respLatency := map[string]int64{}
+	err := json.Unmarshal([]byte(data.Data), &respLatency)
+	if err != nil {
+		log.Println(err)
+		return latencyMap
+	}
+
+	for _, workerClient := range workersList {
+		if latency, ok := respLatency[workerClient.Address]; ok {
+			latencyMap[workerClient] = latency
+		}
 	}
 	return latencyMap
 }

run_local_docker.sh

@@ -3,4 +3,4 @@ docker build . -t cloud-game-local
 docker stop cloud-game-local
 docker rm cloud-game-local
 # Overlord and worker should be run separately. Local is for demo purpose
-docker run --privileged -d --name cloud-game-local -p 8000:8000 cloud-game-local bash -c "cmd -overlordhost ws://localhost:8000/wso & cmd -overlordhost overlord"
+docker run --privileged -d --name cloud-game-local -p 8000:8000 -p 9000:9000 cloud-game-local bash -c "cmd -overlordhost ws://localhost:8000/wso & cmd -overlordhost overlord"

static/game.html

@@ -94,7 +94,7 @@
     <script src="/static/js/gesture_keyboard.js?1"></script>
     <script src="/static/js/gesture_touch.js?1"></script>
     <script src="/static/js/gesture_joystick.js?1"></script>
-    <script src="/static/js/ws.js?2"></script>
+    <script src="/static/js/ws.js?4"></script>
 
     <script src="/static/js/init.js?1"></script>
 

static/js/ws.js

@@ -10,7 +10,6 @@ conn.onopen = () => {
     log("Send ping pong frequently")
     pingpongTimer = setInterval(sendPing, 1000 / PINGPONGPS)
 
-    startWebRTC();
 }
 
 conn.onerror = error => {
@@ -90,24 +89,63 @@ conn.onmessage = e => {
         var s = d["data"];
         var latencyList = [];
         curPacketID = d["packet_id"];
+        latencyPacketID = curPacketID;
         addrs = s.split(",")
+
+        var latenciesMap = {};
+        var cntResp = 0;
+        beforeTime = Date.now();
         for (const addr of addrs) {
-            beforeTime = Date.now();
+            var sumLatency = 0
 
+            // TODO: Clean code, use async
             var xmlHttp = new XMLHttpRequest();
-            xmlHttp.open( "GET", addr+"/echo", false ); // false for synchronous request
-            xmlHttp.send( null );
+            xmlHttp.open( "GET", "http://"+addr+":9000/echo?_=" + beforeTime, true ); // false for synchronous request, add date to not calling cache
+            xmlHttp.timeout = 1000
+            xmlHttp.ontimeout = () => {
+                cntResp++;
+                afterTime = Date.now();
+                //sumLatency += afterTime - beforeTime
+                latenciesMap[addr] = afterTime - beforeTime
+                if (cntResp == addrs.length) {
+                    log(`Send latency list ${latenciesMap}`)
+                    log(curPacketID)
 
-            resp = xmlHttp.responseText
-            afterTime = Date.now();
-            latencyList.push(afterTime - beforeTime)
+                    conn.send(JSON.stringify({"id": "checkLatency", "data": JSON.stringify(latenciesMap), "packet_id": latencyPacketID}));
+                    startWebRTC();
+        }
+            }
+            xmlHttp.onload = () => {
+                cntResp++;
+                afterTime = Date.now();
+                //sumLatency += afterTime - beforeTime
+                latenciesMap[addr] = afterTime - beforeTime
+                if (cntResp == addrs.length) {
+                    log(`Send latency list ${latenciesMap}`)
+                    log(curPacketID)
+
+                    //conn.send(JSON.stringify({"id": "checkLatency", "data": latenciesMap, "packet_id": latencyPacketID}));
+                    conn.send(JSON.stringify({"id": "checkLatency", "data": JSON.stringify(latenciesMap), "packet_id": latencyPacketID}));
+                    startWebRTC();
+        }
+            }
+            xmlHttp.send( null );
         }
-        log(`Send latency list ${latencyList.join()}`)
-        log(curPacketID)
-        conn.send(JSON.stringify({"id": "checkLatency", "data": latencyList.join(), "packet_id": curPacketID}));
     }
 }
 
+function updateLatencies(beforeTime, addr, latenciesMap, cntResp, curPacketID) {
+        afterTime = Date.now();
+        //sumLatency += afterTime - beforeTime
+        latenciesMap[addr] = afterTime - beforeTime
+        if (cntResp == addrs.length) {
+            log(`Send latency list ${latenciesMap}`)
+            log(curPacketID)
+
+            conn.send(JSON.stringify({"id": "checkLatency", "data": latenciesMap, "packet_id": curPacketID}));
+        }
+}
+
 function sendPing() {
     // TODO: format the package with time
     conn.send(JSON.stringify({"id": "heartbeat", "data": Date.now().toString()}));
@@ -256,7 +294,8 @@ function startWebRTC() {
                 session = btoa(JSON.stringify(pc.localDescription));
                 log("Send SDP to remote peer");
                 // TODO: Fix curPacketID
-                conn.send(JSON.stringify({"id": "initwebrtc", "data": session, "packet_id": curPacketID}));
+                //conn.send(JSON.stringify({"id": "initwebrtc", "data": session, "packet_id": curPacketID}));
+                conn.send(JSON.stringify({"id": "initwebrtc", "data": session}));
                 iceSent = true
             }
         } else {
@@ -267,7 +306,7 @@ function startWebRTC() {
                 if (!iceSent) {
                     log("Ice gathering timeout, send anyway")
                     session = btoa(JSON.stringify(pc.localDescription));
-                    conn.send(JSON.stringify({"id": "initwebrtc", "data": session, "packet_id": curPacketID}));
+                    conn.send(JSON.stringify({"id": "initwebrtc", "data": session}));
                     iceSent = true;
                 }
             }, ICE_TIMEOUT)