Use singleton batcher (#35)

* use singleton batcher

* Fix singleton pattern

* Bump versions

---------

Co-authored-by: xinghengwang <xing@moesif.com>

Author: selectiveduplicate

lib/batcher.js

@@ -1,33 +1,46 @@
+class SingletonBatcher {
+  static instance;
 
+  constructor(handleBatch, maxSize, maxTime) {
+    if (SingletonBatcher.instance) {
+      SingletonBatcher.instance.handleBatch = handleBatch;
+      SingletonBatcher.instance.maxSize = maxSize;
+      SingletonBatcher.instance.maxTime = maxTime;
 
-function createBatcher(handleBatch, maxSize, maxTime) {
-    return {
-      dataArray: [],
-      // using closure, so no need to keep as part of the object.
-      // maxSize: maxSize,
-      // maxTime: maxTime,
-      add: function(data) {
-        this.dataArray.push(data);
-        if (this.dataArray.length >= maxSize) {
-          this.flush();
-        } else if (maxTime && this.dataArray.length === 1) {
-          var self = this;
-          this._timeout = setTimeout(function() {
-            self.flush();
-          }, maxTime);
-        }
-      },
-      flush: function() {
-        // note, in case the handleBatch is a
-        // delayed function, then it swaps before
-        // sending the current data.
-        clearTimeout(this._timeout);
-        this._lastFlush = Date.now();
-        var currentDataArray = this.dataArray;
-        this.dataArray = [];
-        handleBatch(currentDataArray);
-      }
-    };
+      return SingletonBatcher.instance;
+    }
+    this.dataArray = [];
+    this.handleBatch = handleBatch;
+    this.maxSize = maxTime;
+    SingletonBatcher.instance = this;
+  }
+
+  add(data) {
+    this.dataArray.push(data);
+    if (this.dataArray.length >= this.maxSize) {
+      this.flush();
+    } else if (this.maxTime && this.dataArray.length === 1) {
+      var self = this;
+      this._timeout = setTimeout(() => {
+        self.flush();
+      }, this.maxTime);
+    }
+  }
+
+  flush() {
+    // note, in case the handleBatch is a
+    // delayed function, then it swaps before
+    // sending the current data.
+    clearTimeout(this._timeout);
+    this._lastFlush = Date.now();
+    var currentDataArray = this.dataArray;
+    this.dataArray = [];
+    this.handleBatch(currentDataArray);
   }
-  
-  module.exports = createBatcher;
+}
+
+function createBatcher(handleBatch, maxSize, maxTime) {
+  return new SingletonBatcher(handleBatch, maxSize, maxTime);
+}
+
+module.exports = createBatcher;

lib/index.js

@@ -70,7 +70,7 @@ module.exports = function (options, handler) {
   // config moesifapi
   var config = moesifapi.configuration;
   config.ApplicationId = options.applicationId || options.ApplicationId || process.env.MOESIF_APPLICATION_ID;
-  config.UserAgent = 'moesif-aws-lambda-nodejs/' + '2.0.6';
+  config.UserAgent = 'moesif-aws-lambda-nodejs/' + '2.0.7';
   config.BaseUri = options.baseUri || options.BaseUri || config.BaseUri;
   var moesifController = moesifapi.ApiController;
 

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "moesif-aws-lambda",
-  "version": "2.0.6",
+  "version": "2.0.7",
   "description": "API Monitoring Middleware for AWS Lambda",
   "main": "lib/index.js",
   "keywords": [