text: /*
   *  Copyright (c) 2016 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.
   */
  
  #ifndef WEBRTC_MODULES_AUDIO_PROCESSING_ECHO_DETECTOR_CIRCULAR_BUFFER_H_
  #define WEBRTC_MODULES_AUDIO_PROCESSING_ECHO_DETECTOR_CIRCULAR_BUFFER_H_
  
  #include <vector>
  
  #include "webrtc/base/optional.h"
  
  namespace webrtc {
  
  // Ring buffer containing floating point values.
  struct CircularBuffer {
   public:
    explicit CircularBuffer(size_t size);
    ~CircularBuffer();
  
    void Push(float value);
    rtc::Optional<float> Pop();
    size_t Size() const { return nr_elements_in_buffer_; }
    // This function fills the buffer with zeros, but does not change its size.
    void Clear();
  
   private:
    std::vector<float> buffer_;
    size_t next_insertion_index_ = 0;
    // This is the number of elements that have been pushed into the circular
    // buffer, not the allocated buffer size.
    size_t nr_elements_in_buffer_ = 0;
  };
  
  }  // namespace webrtc
  
  #endif  // WEBRTC_MODULES_AUDIO_PROCESSING_ECHO_DETECTOR_CIRCULAR_BUFFER_H_
  