Add event emitter for get_vp

src/ee.ts

@@ -0,0 +1,19 @@
+import events from 'events';
+import { sha256 } from './utils';
+
+const eventEmitter = new events.EventEmitter();
+eventEmitter.setMaxListeners(1000); // https://stackoverflow.com/a/26176922
+
+export default async function serve(id, action, args) {
+  const key = sha256(id);
+  return new Promise(async (resolve, reject) => {
+    eventEmitter.once(key, (data) => (data.error ? reject(data.e) : resolve(data)));
+    if (eventEmitter.listenerCount(key) === 1) {
+      try {
+        eventEmitter.emit(key, await action(...args));
+      } catch (e) {
+        eventEmitter.emit(key, { error: true, e });
+      }
+    }
+  });
+}

src/rpc.ts

@@ -5,6 +5,7 @@ import { clone, formatStrategies, rpcSuccess, rpcError, blockNumByNetwork } from
 import { version } from '../package.json';
 import { getVp, validate } from './methods';
 import disabled from './disabled.json';
+import serve from './ee';
 
 const router = express.Router();
 
@@ -15,7 +16,7 @@ router.post('/', async (req, res) => {
 
   if (method === 'get_vp') {
     try {
-      return await getVp(res, params, id);
+      return await serve(JSON.stringify(params), getVp, [res, params, id]);
     } catch (e) {
       console.log('[rpc] get_vp failed', params.space, e);
       return rpcError(res, 500, e, id);