优化保存恢复功能

src/global.ts

@@ -0,0 +1,3 @@
+ 
+// 测试项目部署请看 README.md
+export const rootPath = '../digital-vcd-render/public';

src/main.ts

@@ -1,12 +1,11 @@
-import * as path from 'path';
-import * as fs from 'fs';
+
 
 import express, { Request, Response } from 'express';
 import morgan from 'morgan';
 import cors from 'cors';
 
 import bodyParser from 'body-parser';
-import { BSON } from 'bson';
+import { saveView } from './save-view';
 
 const corsOptions = {
     // 一些旧版浏览器（如 IE11、各种 SmartTV）在 204 状态下会有问题
@@ -21,25 +20,12 @@ app.use(bodyParser.json());
 app.use(bodyParser.urlencoded({ extended: true }));
 app.use(morgan('dev'));
 
-// 测试项目部署请看 README.md
-const rootPath = '../digital-vcd-render/public';
 
 app.get('/', (req: Request, res: Response) => {
     res.send('<h1>Hello, World!</h1><br><img src="https://picx.zhimg.com/v2-b4251de7d2499e942c7ebf447a90d2eb_l.jpg"/>');
 });
 
-app.post('/save-view', async (req: Request, res: Response) => {    
-    try {
-        const { file, payload } = req.body;        
-        const savePath = path.join(rootPath, file);
-        const buffer = BSON.serialize(payload);
-        fs.writeFileSync(savePath, buffer);
-        res.send('success');
-    } catch (error) {
-        console.log('error happen in /save-view, ' + error);
-        res.send('error');
-    }
-})
+app.post('/save-view', saveView);
 
 const PORT = process.env.PORT || 3000;
 app.listen(PORT, () => {

src/save-view.ts

@@ -0,0 +1,27 @@
+import { Request, Response } from 'express';
+import * as path from 'path';
+import * as fs from 'fs';
+import { BSON } from 'bson';
+import { rootPath } from './global';
+
+const payloadCache = new Map<string, any>();
+
+export async function saveView(req: Request, res: Response) {
+    try {
+        const { file, payload } = req.body;
+        if (!payloadCache.has(file)) {
+            payloadCache.set(file, payload);
+        }
+
+        const originPayload = payloadCache.get(file);
+        Object.assign(originPayload, payload);
+
+        const savePath = path.join(rootPath, file);
+        const buffer = BSON.serialize(originPayload);
+        fs.writeFileSync(savePath, buffer);
+        res.send('success');
+    } catch (error) {
+        console.log('error happen in /save-view, ' + error);
+        res.send('error');
+    }
+}