Repo created

TMessagesProj/jni/voip/webrtc/rtc_base/numerics/moving_average.cc

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+/*
+ *  Copyright (c) 2018 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "rtc_base/numerics/moving_average.h"
+
+#include <algorithm>
+
+#include "rtc_base/checks.h"
+
+namespace rtc {
+
+MovingAverage::MovingAverage(size_t window_size) : history_(window_size, 0) {
+  // Limit window size to avoid overflow.
+  RTC_DCHECK_LE(window_size, (int64_t{1} << 32) - 1);
+}
+MovingAverage::~MovingAverage() = default;
+
+void MovingAverage::AddSample(int sample) {
+  count_++;
+  size_t index = count_ % history_.size();
+  if (count_ > history_.size())
+    sum_ -= history_[index];
+  sum_ += sample;
+  history_[index] = sample;
+}
+
+absl::optional<int> MovingAverage::GetAverageRoundedDown() const {
+  if (count_ == 0)
+    return absl::nullopt;
+  return sum_ / Size();
+}
+
+absl::optional<int> MovingAverage::GetAverageRoundedToClosest() const {
+  if (count_ == 0)
+    return absl::nullopt;
+  return (sum_ + Size() / 2) / Size();
+}
+
+absl::optional<double> MovingAverage::GetUnroundedAverage() const {
+  if (count_ == 0)
+    return absl::nullopt;
+  return sum_ / static_cast<double>(Size());
+}
+
+void MovingAverage::Reset() {
+  count_ = 0;
+  sum_ = 0;
+}
+
+size_t MovingAverage::Size() const {
+  return std::min(count_, history_.size());
+}
+}  // namespace rtc