useing go routines for read and write in same end point

go/server.go

@@ -3,6 +3,7 @@ package main
 import (
 	"encoding/json"
 	"flag"
+	"fmt"
 	"log"
 	"net/http"
 	"time"
@@ -14,17 +15,33 @@ var upgrader = websocket.Upgrader{
 	ReadBufferSize:  2048,
 	WriteBufferSize: 2048,
 }
-var img = GetImage(1000, 1000)
+var img = GetImage(10, 10)
+var tmpImage = GetImage(img.width, img.height)
 
-func set(w http.ResponseWriter, r *http.Request) {
+func serve(w http.ResponseWriter, r *http.Request) {
 	c, err := upgrader.Upgrade(w, r, nil)
 	if err != nil {
 		log.Print("error while upgrading", err)
 		return
 	}
 	defer c.Close()
+	ticker := time.NewTicker(1 * time.Second)
+	go func() {
+		for range ticker.C {
+			diff := tmpImage.GetDiff(&img)
+			msg, err := json.Marshal(diff)
+			fmt.Println(diff)
+			// TODO only write chenaged pixels to channel instead of entire image
+			err = c.WriteMessage(1, msg)
+			if err != nil {
+				log.Println("error while writing image", err)
+				break
+			}
+			copy(img.pixels, tmpImage.pixels)
+		}
+	}()
 	for {
-		mt, msg, err := c.ReadMessage()
+		_, msg, err := c.ReadMessage()
 		if err != nil {
 			log.Println("read:", err)
 			break
@@ -33,39 +50,8 @@ func set(w http.ResponseWriter, r *http.Request) {
 		message := Message{}
 		message.JsonToStruct(msg)
 		img.SetPixel(message)
+	}
 
-		err = c.WriteMessage(mt, msg)
-		if err != nil {
-			log.Println("write:", err)
-			break
-		}
-	}
-}
-
-func get(w http.ResponseWriter, r *http.Request) {
-	c, err := upgrader.Upgrade(w, r, nil)
-	if err != nil {
-		log.Print("error while upgrading", err)
-		return
-	}
-	defer c.Close()
-	log.Println("Client Connected")
-	ticker := time.NewTicker(1 * time.Second)
-	go func() {
-		for range ticker.C {
-			tmpImage := GetImage(img.width, img.height)
-			diff := tmpImage.GetDiff(&img)
-			msg, err := json.Marshal(diff)
-			err = c.WriteMessage(1, msg)
-			if err != nil {
-				log.Println("error while writing image", err)
-			}
-			copy(tmpImage.pixels, img.pixels)
-		}
-	}()
-	if err != nil {
-		log.Println(err)
-	}
 }
 
 func main() {
@@ -73,7 +59,6 @@ func main() {
 
 	flag.Parse()
 	log.SetFlags(0)
-	http.HandleFunc("/set", set)
-	http.HandleFunc("/get", get)
+	http.HandleFunc("/", serve)
 	log.Fatal(http.ListenAndServe(*addr, nil))
 }

go/util.go

@@ -90,7 +90,7 @@ func comparePixels(pixel1 *pixel, pixel2 *pixel) bool {
 func (img *image) GetDiff(img2 *image) messageImage {
 	diff := GetMessageImage(img.width, img.height)
 	for i := 0; i < int(img.width*img.height); i++ {
-		if comparePixels(&img.pixels[i], &img2.pixels[i]) {
+		if !comparePixels(&img.pixels[i], &img2.pixels[i]) {
 			diff.Pixels[i].Color = img2.pixels[i].Color
 			diff.Pixels[i].UserID = img2.pixels[i].UserID
 			diff.Pixels[i].Timestamp = img2.pixels[i].Timestamp

python/clients.py

@@ -5,6 +5,7 @@ from dataclasses import dataclass
 import datetime
 
 import json
+import random
 import time
 
 import websockets
@@ -20,17 +21,22 @@ class pixel:
 
 
 async def main():
-    message = pixel(
-        x=11,
-        y=0,
-        color=15,
-        timestamp=int(time.time()),
-        userid=1,
-    )
-    async with websockets.connect("ws://localhost:8080/set") as websocket:
-        print(message)
-        await websocket.send(json.dumps(message.__dict__))
-        await websocket.recv()
+
+    async with websockets.connect("ws://localhost:8080/") as websocket:
+        for i in range(10):
+            message = pixel(
+                x=random.randint(0, 10),
+                y=random.randint(0, 10),
+                color=random.randint(0,15),
+                timestamp=int(time.time()),
+                userid=1,
+            )
+            print(message)
+            await websocket.send(json.dumps(message.__dict__))
+        print(await websocket.recv())
+        while True:
+            x = await websocket.recv()
+            print(x)
 
 
 if __name__ == "__main__":