Show max latency on client's status bar

remoting/webapp/base/js/stats_accumulator.js

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /**
  * @fileoverview
  * The webapp reads the plugin's connection statistics frequently (once per
  * second). It logs statistics to the server less frequently, to keep
  * bandwidth and storage costs down. This class bridges that gap, by
  * accumulating high-frequency numeric data, and providing statistics
@@ skipping 76 matching lines @@
     var sum = 0;
     for (var i = 0; i < values.length; i++) {
       sum += values[i];
     }
     return sum / values.length;
   };
   return this.map(key, calcMean);
 };
 
 /**
+ * Finds the max of the values for a given key.
+ *
+ * @param {string} key
+ * @return {number} the max of the values for that key
+ */
+remoting.StatsAccumulator.prototype.calcMax = function(key) {
+  /**
+   * @param {Array<number>} values
+   * @return {number}
+   */
+  var calcMax = function(values) {
+    if (values.length == 0) {

[kelvinp, 2016/03/21 19:14:36]

can be simplified as 

var calcMax = function(values) {
  return Math.max.apply(null, values);
}

[Yuwei, 2016/03/21 19:29:25]

Acknowledged. Interesting that Math.max doesn't have a max(numberArray) form...

+      return 0.0;
+    }
+    var max = -1;
+    for (var i = 0; i < values.length; i++) {
+      if (max < values[i]) {
+        max = values[i];
+      }
+    }
+    return max;
+  };
+  return this.map(key, calcMax);
+};
+
+// Can refactor calcMean and calcMax in functional way

[Sergey Ulanov, 2016/03/21 19:35:06]

If there is a good reason to refactor them then this should be a TODO. If there
is no reason to refactor them, then you don't need this comment.

[Yuwei, 2016/03/21 19:59:40]

Acknowledged.

+
+/**
  * Applies a given map to the list of values for a given key.
  *
  * @param {string} key
  * @param {function(Array<number>): number} map
  * @return {number} the result of applying that map to the list of values for
  *     that key
  */
 remoting.StatsAccumulator.prototype.map = function(key, map) {
   return map(this.getValueList(key));
 };
@@ skipping 22 matching lines @@
  */
 remoting.StatsAccumulator.prototype.getPerfStats = function() {
   var stats = new remoting.ClientSession.PerfStats();
   stats.videoBandwidth = this.calcMean('videoBandwidth');
   stats.captureLatency = this.calcMean('captureLatency');
   stats.encodeLatency = this.calcMean('encodeLatency');
   stats.decodeLatency = this.calcMean('decodeLatency');
   stats.renderLatency = this.calcMean('renderLatency');
   stats.roundtripLatency = this.calcMean('roundtripLatency');
 
+  stats.maxCaptureLatency = this.calcMax('maxCaptureLatency');
+  stats.maxEncodeLatency = this.calcMax('maxEncodeLatency');
+  stats.maxDecodeLatency = this.calcMax('maxDecodeLatency');
+  stats.maxRenderLatency = this.calcMax('maxRenderLatency');
+  stats.maxRoundtripLatency = this.calcMax('maxRoundtripLatency');
+
   for (var key in stats) {
     if (stats[key] !== 0) {
       return stats;
     }
   }
   return null;
 };