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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-*/
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
#ifndef MOZILLA_AUDIO_RING_BUFFER_H_
#define MOZILLA_AUDIO_RING_BUFFER_H_
#include "AudioSampleFormat.h"
#include "mozilla/Span.h"
#include <functional>
namespace mozilla {
/**
* AudioRingBuffer works with audio sample format float or short. The
* implementation wrap around the RingBuffer thus it is not thread-safe. Reads
* and writes must happen in the same thread which may be different than the
* construction thread. The memory is pre-allocated in the constructor, but may
* also be re-allocated on the fly should a larger length be needed. The sample
* format has to be specified in order to be used.
*/
class AudioRingBuffer final {
public:
explicit AudioRingBuffer(uint32_t aSizeInBytes);
~AudioRingBuffer();
/**
* Set the sample format to either short or float. The sample format must be
* set before the using any other method.
*/
void SetSampleFormat(AudioSampleFormat aFormat);
/**
* Write `aBuffer.Length()` number of samples when the format is float.
*/
uint32_t Write(const Span<const float>& aBuffer);
/**
* Write `aBuffer.Length()` number of samples when the format is short.
*/
uint32_t Write(const Span<const int16_t>& aBuffer);
/**
* Write `aSamples` number of samples from `aBuffer`. Note the `aBuffer` does
* not change.
*/
uint32_t Write(const AudioRingBuffer& aBuffer, uint32_t aSamples);
/**
* Write `aSamples` number of zeros before the beginning of the existing data.
*/
uint32_t PrependSilence(uint32_t aSamples);
/**
* Write `aSamples` number of zeros.
*/
uint32_t WriteSilence(uint32_t aSamples);
/**
* Read `aBuffer.Length()` number of samples when the format is float.
*/
uint32_t Read(const Span<float>& aBuffer);
/**
* Read `aBuffer.Length()` number of samples when the format is short.
*/
uint32_t Read(const Span<int16_t>& aBuffer);
/**
* Read the internal buffer without extra copies when sample format is float.
* Check also the RingBuffer::ReadNoCopy() for more details.
*/
uint32_t ReadNoCopy(
std::function<uint32_t(const Span<const float>&)>&& aCallable);
/**
* Read the internal buffer without extra copies when sample format is short.
* Check also the RingBuffer::ReadNoCopy() for more details.
*/
uint32_t ReadNoCopy(
std::function<uint32_t(const Span<const int16_t>&)>&& aCallable);
/**
* Remove `aSamples` number of samples.
*/
uint32_t Discard(uint32_t aSamples);
/**
* Remove all available samples.
*/
uint32_t Clear();
/**
* Increase the ring buffer size if necessary to at least the specified length
* in bytes. Must be divisible by the sample size.
* Will not deallocate memory if the underlying buffer is large enough.
* Returns false if memory allocation is required and fails.
*/
bool EnsureLengthBytes(uint32_t aLengthBytes);
/**
* Return the number of samples this buffer can hold.
*/
uint32_t Capacity() const;
/**
* Return true if the buffer is full.
*/
bool IsFull() const;
/**
* Return true if the buffer is empty.
*/
bool IsEmpty() const;
/**
* Return the number of samples available for writing.
*/
uint32_t AvailableWrite() const;
/**
* Return the number of samples available for reading.
*/
uint32_t AvailableRead() const;
private:
class AudioRingBufferPrivate;
UniquePtr<AudioRingBufferPrivate> mPtr;
};
} // namespace mozilla
#endif // MOZILLA_AUDIO_RING_BUFFER_H_