Уменьшение запросов get-state к api, добавлен метод get-state-finish

server/controllers/WorkerController.js

@@ -1,5 +1,6 @@
 const BaseController = require('./BaseController');
 const WorkerState = require('../core/WorkerState');//singleton
+const utils = require('../core/utils');
 
 class WorkerController extends BaseController {
     constructor(config) {
@@ -15,6 +16,7 @@ class WorkerController extends BaseController {
                 throw new Error(`key 'workerId' is wrong`);
 
             const state = this.workerState.getState(request.workerId);
+
             return (state ? state : {});
         } catch (e) {
             error = e.message;
@@ -23,6 +25,59 @@ class WorkerController extends BaseController {
         res.status(400).send({error});
         return false;
     }
+
+    async getStateFinish(req, res) {
+        const request = req.body;
+        let error = '';
+        try {
+            if (!request.workerId)
+                throw new Error(`key 'workerId' is wrong`);
+
+            res.writeHead(200, {
+                'Content-Type': 'text/json; charset=utf-8',
+            });
+
+            const splitter = '-- aod2t5hDXU32bUFyqlFE next status --';            
+            const refreshPause = 300;
+            let i = 0;
+            let prevProgress = -1;
+            let prevState = '';
+            let state;
+            while (1) {// eslint-disable-line no-constant-condition
+                state = this.workerState.getState(request.workerId);
+                if (!state) break;
+
+                res.write(splitter + JSON.stringify(state));
+                res.flush();
+
+                if (state.state != 'finish')
+                    await utils.sleep(refreshPause);
+                else
+                    break;
+
+                i++;
+                if (i > 2*60*1000/refreshPause) {//2 мин ждем телодвижений воркера
+                    res.write(splitter + JSON.stringify({state: 'error', error: 'Слишком долгое время ожидания'}));
+                    break;
+                }
+                i = (prevProgress != state.progress || prevState != state.state ? 1 : i);
+                prevProgress = state.progress;
+                prevState = state.state;
+            }
+            
+            if (!state) {
+                res.write(splitter + JSON.stringify({}));
+            }
+
+            res.end();
+            return false;
+        } catch (e) {
+            error = e.message;
+        }
+        //bad request
+        res.status(400).send({error});
+        return false;
+    }
 }
 
 module.exports = WorkerController;