| // Copyright 2016 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. |
| |
| #ifndef REMOTING_BASE_RUNNING_SAMPLES_H_ |
| #define REMOTING_BASE_RUNNING_SAMPLES_H_ |
| |
| #include <stddef.h> |
| #include <stdint.h> |
| |
| #include "base/containers/circular_deque.h" |
| #include "base/macros.h" |
| #include "base/threading/thread_checker.h" |
| |
| namespace remoting { |
| |
| // Calculates the maximum or average of the most recent N recorded samples. |
| // This is typically used to smooth out random variation in point samples |
| // over bandwidth, frame rate, etc. |
| class RunningSamples { |
| public: |
| // Constructs a running sample helper that stores |window_size| most |
| // recent samples. |
| explicit RunningSamples(int window_size); |
| virtual ~RunningSamples(); |
| |
| // Records a point sample. |
| void Record(int64_t value); |
| |
| // Returns the average over up to |window_size| of the most recent samples. |
| // 0 if no sample available |
| double Average() const; |
| |
| // Returns the max over up to |window_size| of the most recent samples. |
| // 0 if no sample available |
| int64_t Max() const; |
| |
| // Whether there is at least one record. |
| bool IsEmpty() const; |
| |
| private: |
| // Stores the desired window size, as size_t to avoid casting when comparing |
| // with the size of |data_points_|. |
| const size_t window_size_; |
| |
| // Stores the |window_size| most recently recorded samples. |
| base::circular_deque<int64_t> data_points_; |
| |
| // Holds the sum of the samples in |data_points_|. |
| int64_t sum_ = 0; |
| |
| base::ThreadChecker thread_checker_; |
| |
| DISALLOW_COPY_AND_ASSIGN(RunningSamples); |
| }; |
| |
| } // namespace remoting |
| |
| #endif // REMOTING_BASE_RUNNING_SAMPLES_H_ |