tor-browser

The Tor Browser
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ring_buffer.h (2105B)


      1 /*
      2 *  Copyright (c) 2018 The WebRTC project authors. All Rights Reserved.
      3 *
      4 *  Use of this source code is governed by a BSD-style license
      5 *  that can be found in the LICENSE file in the root of the source
      6 *  tree. An additional intellectual property rights grant can be found
      7 *  in the file PATENTS.  All contributing project authors may
      8 *  be found in the AUTHORS file in the root of the source tree.
      9 */
     10 
     11 #ifndef MODULES_AUDIO_PROCESSING_AGC2_RNN_VAD_RING_BUFFER_H_
     12 #define MODULES_AUDIO_PROCESSING_AGC2_RNN_VAD_RING_BUFFER_H_
     13 
     14 #include <array>
     15 #include <cstring>
     16 #include <type_traits>
     17 
     18 #include "api/array_view.h"
     19 #include "rtc_base/checks.h"
     20 
     21 namespace webrtc {
     22 namespace rnn_vad {
     23 
     24 // Ring buffer for N arrays of type T each one with size S.
     25 template <typename T, int S, int N>
     26 class RingBuffer {
     27  static_assert(S > 0, "");
     28  static_assert(N > 0, "");
     29  static_assert(std::is_arithmetic<T>::value,
     30                "Integral or floating point required.");
     31 
     32 public:
     33  RingBuffer() : tail_(0) {}
     34  RingBuffer(const RingBuffer&) = delete;
     35  RingBuffer& operator=(const RingBuffer&) = delete;
     36  ~RingBuffer() = default;
     37  // Set the ring buffer values to zero.
     38  void Reset() { buffer_.fill(0); }
     39  // Replace the least recently pushed array in the buffer with `new_values`.
     40  void Push(ArrayView<const T, S> new_values) {
     41    std::memcpy(buffer_.data() + S * tail_, new_values.data(), S * sizeof(T));
     42    tail_ += 1;
     43    if (tail_ == N)
     44      tail_ = 0;
     45  }
     46  // Return an array view onto the array with a given delay. A view on the last
     47  // and least recently push array is returned when `delay` is 0 and N - 1
     48  // respectively.
     49  ArrayView<const T, S> GetArrayView(int delay) const {
     50    RTC_DCHECK_LE(0, delay);
     51    RTC_DCHECK_LT(delay, N);
     52    int offset = tail_ - 1 - delay;
     53    if (offset < 0)
     54      offset += N;
     55    return {buffer_.data() + S * offset, S};
     56  }
     57 
     58 private:
     59  int tail_;  // Index of the least recently pushed sub-array.
     60  std::array<T, S * N> buffer_{};
     61 };
     62 
     63 }  // namespace rnn_vad
     64 }  // namespace webrtc
     65 
     66 #endif  // MODULES_AUDIO_PROCESSING_AGC2_RNN_VAD_RING_BUFFER_H_