Code cleanup and optimization - removed debug logs and comments

server.js

@@ -9,6 +9,10 @@ const app = express();
 
 const server = http.createServer(app);
 
+let cachedPrices = null;
+let lastFetchTime = 0;
+const CACHE_DURATION = 30000;
+
 const io = socketIo(server, {
   cors: {
     origin: process.env.CORS_ORIGIN || "*",
@@ -34,63 +38,69 @@ app.get("/health", (req, res) => {
 
 // ========== Socket.IO Logic ==========
 
-// 用於追蹤連接的客戶端數量
+// Number of clients
 let connectedClients = 0;
 
-// 當客戶端連接時觸發
+// Trigger when client connected
 io.on("connection", (socket) => {
-  // 增加客戶端計數
   connectedClients++;
 
-  console.log(`✅ 客戶端已連接: ${socket.id}`);
-  console.log(`📊 當前連接數: ${connectedClients}`);
+  console.log(`✅ Client Connected: ${socket.id}`);
+  console.log(`📊 Current Number of Clients: ${connectedClients}`);
 
-  // 向所有客戶端廣播當前連接數
+  // Broadcast to all clients
   io.emit("clientCount", connectedClients);
 
-  // ========== 監聽客戶端事件 ==========
+  // ========== Monitoring client side events ==========
 
-  // 當客戶端要求數據時
+  // Request Data
   socket.on("requestData", async (dataType) => {
-    console.log(`📤 數據請求: ${dataType}`);
+    console.log(`📤 Request Data: ${dataType}`);
+    const now = new Date();
 
     try {
       let data;
 
       if (dataType === "crypto") {
-        // 從 CoinGecko API 獲取加密貨幣數據
-        const response = await axios.get(
-          "https://api.coingecko.com/api/v3/simple/price",
-          {
-            params: {
-              // 要查詢的加密貨幣
-              ids: "bitcoin,ethereum,cardano,solana,ripple",
-              // 使用 USD 幣種
-              vs_currencies: "usd",
-              // 包含市值
-              include_market_cap: true,
-              // 包含24小時交易量
-              include_24hr_vol: true,
-              // 包含24小時漲跌幅
-              include_24hr_change: true,
-            },
-          }
-        );
+        if (cachedPrices && now - lastFetchTime < CACHE_DURATION) {
+          console.log("📦 Use caching data");
+          data = cachedPrices;
+        } else {
+          // Get data from "CoinGecko API"
+          const response = await axios.get(
+            "https://api.coingecko.com/api/v3/simple/price",
+            {
+              params: {
+                // list of crypto requested to be shown
+                ids: "bitcoin,ethereum,cardano,solana,ripple",
+                vs_currencies: "usd",
+                include_market_cap: true,
+                include_24hr_vol: true,
+                include_24hr_change: true,
+              },
+            }
+          );
 
-        // 組織數據格式
-        data = {
-          type: "crypto",
-          timestamp: new Date(),
-          prices: response.data,
-        };
+          // Construct data format
+          data = {
+            type: "crypto",
+            timestamp: new Date(),
+            prices: response.data,
+          };
+
+          // Update Caches
+          cachedPrices = data;
+          lastFetchTime = now;
+          console.log("✅ Cached New Data");
+        }
       }
 
-      // 發送數據給要求的客戶端
+      // Emit data to client side
       socket.emit("data", data);
-      console.log(`✅ 數據已發送給客戶端: ${socket.id}`);
+      console.log(`✅ Data sent to client: ${socket.id}`);
     } catch (error) {
-      console.error("❌ 獲取數據出錯:", error.message);
-      // 發送錯誤信息給客戶端
+      console.error("❌ Error on Getting Data:", error.message);
+      // Emit Error message to client side
       socket.emit("error", {
         message: "Failed to fetch data",
         details: error.message,
@@ -98,12 +108,19 @@ io.on("connection", (socket) => {
     }
   });
 
-  // ========== 定期推送數據 ==========
+  // ========== Push Data by interval ==========
 
-  // 創建定時器，每5秒推送一次數據給該客戶端
+  // Push every 5 seconds
   const dataInterval = setInterval(async () => {
     try {
-      // 獲取最新的加密貨幣數據
+      const now = new Date();
+
+      if (cachedPrices && now - lastFetchTime < CACHE_DURATION) {
+        socket.emit("data", cachedPrices);
+        console.log(`[${now.toISOString()}]📦 Push Cached Data`);
+        return;
+      }
+      // Get latest data
       const response = await axios.get(
         "https://api.coingecko.com/api/v3/simple/price",
         {
@@ -117,57 +134,59 @@ io.on("connection", (socket) => {
         }
       );
 
-      // 向該客戶端發送數據（實時更新）
-      socket.emit("data", {
+      const data = {
         type: "crypto",
         timestamp: new Date(),
         prices: response.data,
-      });
+      };
+
+      cachedPrices = data;
+      lastFetchTime = now;
+
+      socket.emit("data", data);
     } catch (error) {
-      console.error("❌ 定時推送出錯:", error.message);
+      console.error("❌ Error on pushing:", error.message);
     }
-  }, 5000); // 每5000毫秒（5秒）執行一次
+  }, CACHE_DURATION); // run every 30 seconds
 
-  // ========== 客戶端斷開連接 ==========
+  // ========== Client Disconnected ==========
 
-  // 當客戶端斷開連接時觸發
+  // Trigger when client disconnected
   socket.on("disconnect", () => {
     connectedClients--;
-    console.log(`❌ 客戶端已斷開: ${socket.id}`);
-    console.log(`📊 當前連接數: ${connectedClients}`);
+    console.log(`❌ Client Disconnected: ${socket.id}`);
+    console.log(`📊 Current Number of Clients: ${connectedClients}`);
 
-    // 向所有客戶端廣播更新的連接數
+    // Broadcast number of clients
     io.emit("clientCount", connectedClients);
 
-    // 清除該客戶端的定時器
+    // Clear client's interval
     clearInterval(dataInterval);
   });
 });
 
-// ========== 啟動服務器 ==========
+// ========== Start service ==========
 
-// 從環境變數獲取端口，或使用默認5000
 const PORT = process.env.PORT || 5000;
 
-// 啟動伺服器
 server.listen(PORT, () => {
   console.log("");
   console.log("═══════════════════════════════════════");
-  console.log(`✅ 服務器運行在: http://localhost:${PORT}`);
-  console.log("📡 WebSocket 已準備接收連接");
-  console.log("🔗 CORS 來源:", process.env.CORS_ORIGIN || "*");
+  console.log(`✅ Server running on: http://localhost:${PORT}`);
+  console.log("📡 WebSocket ready to connect");
+  console.log("🔗 CORS Source:", process.env.CORS_ORIGIN || "*");
   console.log("═══════════════════════════════════════");
   console.log("");
 });
 
-// ========== 錯誤處理 ==========
+// ========== Error Handling ==========
 
-// 處理未捕獲的異常
+// Exception Handling
 process.on("unhandledRejection", (err) => {
-  console.error("❌ 未捕獲的異常:", err);
+  console.error("❌ Exceptions:", err);
 });
 
 process.on("uncaughtException", (err) => {
-  console.error("❌ 未捕獲的異常:", err);
+  console.error("❌ Exceptions:", err);
   process.exit(1);
 });