Show max latency on client's status bar

remoting/base/running_samples.cc

 // 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.
 
-#include "remoting/base/running_average.h"
+#include "remoting/base/running_samples.h"
+
+#include <algorithm>
 
 #include "base/logging.h"
 
 namespace remoting {
 
-RunningAverage::RunningAverage(int window_size)
+RunningSamples::RunningSamples(int window_size)
     : window_size_(window_size),
       sum_(0) {

[Sergey Ulanov, 2016/03/18 19:42:06]

while you are here please remove this initializer and add =0 in the header.

[Yuwei, 2016/03/18 20:05:59]

Then how can we construct RunningSamples...?

[Sergey Ulanov, 2016/03/18 20:17:08]

Sorry for not being clear. My comment was only about sum_(0)  initializer, not
the constructor. C++11 allows to set default initialization value in the class
definition, i.e.:

class A {
 private:
  int sum_ = 0;
};

This will ensure that all constructors that don't have explicit intializer will
set sum_ to 0. This code was written before C++11, so it still uses old style
initialization. 

[Yuwei, 2016/03/18 20:46:47]

Got it:)

   DCHECK_GT(window_size, 0);
 }
 
-RunningAverage::~RunningAverage() {}
+RunningSamples::~RunningSamples() {}
 
-void RunningAverage::Record(int64_t value) {
+void RunningSamples::Record(int64_t value) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   data_points_.push_back(value);
   sum_ += value;
 
   if (data_points_.size() > window_size_) {
     sum_ -= data_points_[0];
     data_points_.pop_front();
   }
 }
 
-double RunningAverage::Average() {
+double RunningSamples::Average() {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   if (data_points_.empty())
     return 0;
   return static_cast<double>(sum_) / data_points_.size();
 }
 
+int64_t RunningSamples::Max() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  if (data_points_.empty())
+    return 0;
+
+  // O(n*w), may be improved.
+  return *std::max_element(data_points_.begin(), data_points_.end());
+}
+
 }  // namespace remoting