From 4886a8a3a0afec089e0a45d4e46434a05298bb21 Mon Sep 17 00:00:00 2001
From: chenos <chenlinxh@gmail.com>
Date: Sun, 5 Sep 2021 14:17:45 +0800
Subject: [PATCH] feat: async event emitter

---
 packages/api/src/index.ts                 | 32 ++++++------
 packages/plugin-collections/src/server.ts |  4 ++
 packages/server/src/application.ts        | 62 +++++++++++++++++++++++
 3 files changed, 82 insertions(+), 16 deletions(-)

diff --git a/packages/api/src/index.ts b/packages/api/src/index.ts
index 85c03b0f9..d9ea9e6e7 100644
--- a/packages/api/src/index.ts
+++ b/packages/api/src/index.ts
@@ -4,22 +4,22 @@ import { middlewares } from '@nocobase/server';
 (async () => {
   api.resourcer.use(middlewares.actionParams());
 
-  await api.loadPlugins();
-
-  if (process.env.NOCOBASE_ENV === 'demo') {
-    api.resourcer.use(middlewares.demoBlacklistedActions({
-      emails: [process.env.ADMIN_EMAIL],
+  api.on('plugins.afterLoad', async () => {
+    console.log('plugins.afterLoad')
+    if (process.env.NOCOBASE_ENV === 'demo') {
+      api.resourcer.use(middlewares.demoBlacklistedActions({
+        emails: [process.env.ADMIN_EMAIL],
+      }));
+    }
+    api.use(middlewares.appDistServe({
+      root: process.env.APP_DIST,
+      useStaticServer: !(process.env.APP_USE_STATIC_SERVER === 'false' || !process.env.APP_USE_STATIC_SERVER),
     }));
-  }
-
-  api.use(middlewares.appDistServe({
-    root: process.env.APP_DIST,
-    useStaticServer: !(process.env.APP_USE_STATIC_SERVER === 'false' || !process.env.APP_USE_STATIC_SERVER),
-  }));
-
-  await api.database.getModel('collections').load();
-
-  api.listen(process.env.API_PORT, () => {
-    console.log(`http://localhost:${process.env.API_PORT}/`);
   });
+
+  const start = Date.now();
+  await api.start(process.env.API_PORT);
+  console.log(api.database.getTables().map(t => t.getName()));
+  console.log(`Start-up time: ${(Date.now() - start) / 1000}s`);
+  console.log(`http://localhost:${process.env.API_PORT}/`);
 })();
diff --git a/packages/plugin-collections/src/server.ts b/packages/plugin-collections/src/server.ts
index 08b1a7df2..005a545d5 100644
--- a/packages/plugin-collections/src/server.ts
+++ b/packages/plugin-collections/src/server.ts
@@ -11,6 +11,10 @@ export default async function (this: Application, options = {}) {
   database.import({
     directory: path.resolve(__dirname, 'collections'),
   });
+  this.on('server.beforeStart', async () => {
+    console.log('server.beforeStart');
+    await database.getModel('collections').load();
+  });
   const [Collection, Field] = database.getModels(['collections', 'fields']);
   Field.beforeCreate(async (model) => {
     if (!model.get('name')) {
diff --git a/packages/server/src/application.ts b/packages/server/src/application.ts
index 32f5dd687..7326ca202 100644
--- a/packages/server/src/application.ts
+++ b/packages/server/src/application.ts
@@ -23,6 +23,60 @@ export class Application extends Koa {
     // this.runHook('afterInit');
   }
 
+  async emitAsync(event: string | symbol, ...args: any[]): Promise<boolean> {
+    // @ts-ignore
+    const events = this._events;
+    let callbacks = events[event];
+    if (!callbacks) {
+      return false;
+    }
+    // helper function to reuse as much code as possible
+    const run = (cb) => {
+      switch (args.length) {
+        // fast cases
+        case 0:
+          cb = cb.call(this);
+          break;
+        case 1:
+          cb = cb.call(this, args[0]);
+          break;
+        case 2:
+          cb = cb.call(this, args[0], args[1]);
+          break;
+        case 3:
+          cb = cb.call(this, args[0], args[1], args[2]);
+          break;
+        // slower
+        default:
+          cb = cb.apply(this, args);
+      }
+
+      if (
+        cb && (
+          cb instanceof Promise ||
+          typeof cb.then === 'function'
+        )
+      ) {
+        return cb;
+      }
+
+      return Promise.resolve(true);
+    };
+
+    if (typeof callbacks === 'function') {
+      await run(callbacks);
+    } else if (typeof callbacks === 'object') {
+      callbacks = callbacks.slice().filter(Boolean);
+      await callbacks.reduce((prev, next) => {
+        return prev.then((res) => {
+          return run(next).then((result) => Promise.resolve(res.concat(result)));
+        });
+      }, Promise.resolve([]));
+    }
+
+    return true;
+  }
+
   registerPlugin(key: string | object, plugin?: any) {
     if (typeof key === 'object') {
       Object.keys(key).forEach((k) => {
@@ -46,10 +100,18 @@ export class Application extends Koa {
   }
 
   async loadPlugins() {
+    await this.emitAsync('plugins.beforeLoad');
     const allPlugins = this.plugins.values();
     for (const plugin of allPlugins) {
       plugin.instance = await this.loadPlugin(plugin);
     }
+    await this.emitAsync('plugins.afterLoad');
+  }
+
+  async start(port) {
+    await this.loadPlugins();
+    await this.emitAsync('server.beforeStart');
+    this.listen(port);
   }
 
   protected async loadPlugin({ entry, options = {} }: { entry: string | Function, options: any }) {