juce_BufferingAudioFormatReader.h

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 /*
  ==============================================================================
 
   This file is part of the JUCE library.
   Copyright (c) 2022 - Raw Material Software Limited
 
   JUCE is an open source library subject to commercial or open-source
   licensing.
 
   By using JUCE, you agree to the terms of both the JUCE 7 End-User License
   Agreement and JUCE Privacy Policy.
 
   End User License Agreement: www.juce.com/juce-7-licence
   Privacy Policy: www.juce.com/juce-privacy-policy
 
   Or: You may also use this code under the terms of the GPL v3 (see
   www.gnu.org/licenses).
 
   JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
   EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
   DISCLAIMED.
 
  ==============================================================================
*/
 
namespace juce
{
 
//==============================================================================
class JUCE_API  BufferingAudioReader  : public AudioFormatReader,
                                        private TimeSliceClient
{
public:
    BufferingAudioReader (AudioFormatReader* sourceReader,
                          TimeSliceThread& timeSliceThread,
                          int samplesToBuffer);
 
    ~BufferingAudioReader() override;
 
    void setReadTimeout (int timeoutMilliseconds) noexcept;
 
    //==============================================================================
    bool readSamples (int* const* destSamples, int numDestChannels, int startOffsetInDestBuffer,
                      int64 startSampleInFile, int numSamples) override;
 
private:
    struct BufferedBlock
    {
        BufferedBlock (AudioFormatReader& reader, int64 pos, int numSamples);
 
        Range<int64> range;
        AudioBuffer<float> buffer;
        bool allSamplesRead = false;
    };
 
    int useTimeSlice() override;
    BufferedBlock* getBlockContaining (int64 pos) const noexcept;
    bool readNextBufferChunk();
 
    static constexpr int samplesPerBlock = 32768;
 
    std::unique_ptr<AudioFormatReader> source;
    TimeSliceThread& thread;
    std::atomic<int64> nextReadPosition { 0 };
    const int numBlocks;
    int timeoutMs = 0;
 
    CriticalSection lock;
    OwnedArray<BufferedBlock> blocks;
 
    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (BufferingAudioReader)
};
 
} // namespace juce