WaveDataCache Class Reference

Cache that contains the waveform data. More...

#include <WaveDataCache.h>

Inheritance diagram for WaveDataCache:

Collaboration diagram for WaveDataCache:

Public Types
using	DataProvider = std::function< bool(int64_t requiredSample, WaveCacheSampleBlock::Type dataType, WaveCacheSampleBlock &block)>
Public Types inherited from GraphicsDataCache< WaveCacheElement >
using	ElementFactory = std::function< std::unique_ptr< WaveCacheElement >()>
using	Initializer = std::function< bool(const GraphicsDataCacheKey &Key, WaveCacheElement &element)>

Public Member Functions
	WaveDataCache (const WaveClip &waveClip, int channelIndex)
Public Member Functions inherited from GraphicsDataCache< WaveCacheElement >
	GraphicsDataCache (const GraphicsDataCache &)=delete
	GraphicsDataCache (double scaledSampleRate, ElementFactory elementFactory)
GraphicsDataCache &	operator= (const GraphicsDataCache &)=delete
	~GraphicsDataCache () override
IteratorRange< GraphicsDataCacheIterator< WaveCacheElement > >	PerformLookup (const ZoomInfo &zoomInfo, double t0, double t1)
const WaveCacheElement *	PerformLookup (GraphicsDataCacheKey key)
void	setInitializer (Initializer initializer)
Public Member Functions inherited from GraphicsDataCacheBase
virtual	~GraphicsDataCacheBase ()=default
void	Invalidate ()
	Invalidate the cache content. More...
double	GetScaledSampleRate () const noexcept
	Returns the sample rate associated with cache. More...
void	UpdateViewportWidth (int64_t width) noexcept
int64_t	GetMaxViewportWidth () const noexcept

Private Member Functions
bool	InitializeElement (const GraphicsDataCacheKey &key, WaveCacheElement &element) override

Private Attributes
DataProvider	mProvider
WaveCacheSampleBlock	mCachedBlock
const WaveClip &	mWaveClip
Observer::Subscription	mStretchChangedSubscription

Additional Inherited Members
Static Public Attributes inherited from GraphicsDataCacheBase
static constexpr uint32_t	CacheElementWidth = 256
Protected Types inherited from GraphicsDataCacheBase
using	Lookup = std::vector< LookupElement >
	Cache lookup is a vector, with items sorted using Key. More...
Protected Member Functions inherited from GraphicsDataCache< WaveCacheElement >
virtual void	CheckCache (const ZoomInfo &, double, double)
virtual bool	InitializeElement (const GraphicsDataCacheKey &key, WaveCacheElement &element)
Protected Member Functions inherited from GraphicsDataCacheBase
	GraphicsDataCacheBase (double scaledSampleRate)
void	SetScaledSampleRate (double scaledSampleRate)
virtual GraphicsDataCacheElementBase *	CreateElement (const GraphicsDataCacheKey &key)=0
	Create a new Cache element. Implementation is responsible of the lifetime control. More...
virtual void	DisposeElement (GraphicsDataCacheElementBase *element)=0
	This method is called, when the cache element should be evicted. Implementation may not deallocate the object. More...
virtual bool	UpdateElement (const GraphicsDataCacheKey &key, GraphicsDataCacheElementBase &element)=0
	This method is called on all elements matching the request that are not complete (i. e. IsComplete if false). More...
BaseLookupResult	PerformBaseLookup (const ZoomInfo &zoomInfo, double t0, double t1)
	Perform a lookup inside the cache. This method modifies mLookup and invalidates any previous result. More...
const GraphicsDataCacheElementBase *	PerformBaseLookup (GraphicsDataCacheKey key)
	Perform a lookup for the given key. This method modifies mLookup and invalidates any previous result. More...

Detailed Description

Cache that contains the waveform data.

Definition at line 92 of file WaveDataCache.h.

Member Typedef Documentation

DataProvider

using WaveDataCache::DataProvider = std::function<bool (int64_t requiredSample, WaveCacheSampleBlock::Type dataType, WaveCacheSampleBlock& block)>

Definition at line 96 of file WaveDataCache.h.

Constructor & Destructor Documentation

WaveDataCache()

WaveDataCache::WaveDataCache	(	const WaveClip &	waveClip,
		int	channelIndex
	)

Definition at line 274 of file WaveDataCache.cpp.

    : GraphicsDataCache<WaveCacheElement>(
         waveClip.GetRate() / waveClip.GetStretchRatio(),
         [] { return std::make_unique<WaveCacheElement>(); })
    , mProvider { MakeDefaultDataProvider(waveClip, channelIndex) }
    , mWaveClip { waveClip }
    , mStretchChangedSubscription {
       const_cast<WaveClip&>(waveClip)
          .Observer::Publisher<StretchRatioChange>::Subscribe(
             [this](const StretchRatioChange&) {
                SetScaledSampleRate(
                   mWaveClip.GetRate() / mWaveClip.GetStretchRatio());
             })
    }
{
}

Member Function Documentation

InitializeElement()

bool WaveDataCache::InitializeElement ( const GraphicsDataCacheKey &  key, WaveCacheElement &  element  )

overrideprivatevirtual

Reimplemented from GraphicsDataCache< WaveCacheElement >.

Definition at line 291 of file WaveDataCache.cpp.

{
   auto sw = FrameStatistics::CreateStopwatch(
      FrameStatistics::SectionID::WaveDataCache);
 
   element.AvailableColumns = 0;
 
   int64_t firstSample = key.FirstSample;
 
   const auto samplesPerColumn =
      std::max(0.0, GetScaledSampleRate() / key.PixelsPerSecond);
 
   const size_t elementSamplesCount =
      samplesPerColumn * WaveDataCache::CacheElementWidth;
   size_t processedSamples = 0;
 
   const WaveCacheSampleBlock::Type blockType =
      samplesPerColumn >= 64 * 1024 ?
         WaveCacheSampleBlock::Type::MinMaxRMS64k :
         (samplesPerColumn >= 256 ? WaveCacheSampleBlock::Type::MinMaxRMS256 :
                                    WaveCacheSampleBlock::Type::Samples);
 
   if (blockType != mCachedBlock.DataType)
      mCachedBlock.Reset();
 
   size_t columnIndex = 0;
 
   for (; columnIndex < WaveDataCache::CacheElementWidth; ++columnIndex)
   {
      WaveCacheSampleBlock::Summary summary;
 
      auto samplesLeft =
         static_cast<size_t>(std::round(samplesPerColumn * (columnIndex + 1)) - std::round(samplesPerColumn * columnIndex));
 
      while (samplesLeft != 0)
      {
         if (!mCachedBlock.ContainsSample(firstSample))
            if (!mProvider(firstSample, blockType, mCachedBlock))
               break;
 
         summary = mCachedBlock.GetSummary(firstSample, samplesLeft, summary);
         if(summary.SamplesCount == 0)
            break;
 
         samplesLeft -= summary.SamplesCount;
         firstSample += summary.SamplesCount;
         processedSamples += summary.SamplesCount;
      }
 
      if (summary.SamplesCount > 0)
      {
         auto& column = element.Data[columnIndex];
 
         column.min = summary.Min;
         column.max = summary.Max;
 
         column.rms = std::sqrt(summary.SquaresSum / summary.SumItemsCount);
      }
 
      if (columnIndex > 0)
      {
         const auto prevColumn = element.Data[columnIndex - 1];
         auto& column = element.Data[columnIndex];
 
         bool updated = false;
 
         if (prevColumn.min > column.max)
         {
            column.max = prevColumn.min;
            updated    = true;
         }
 
         if (prevColumn.max < column.min)
         {
            column.min = prevColumn.max;
            updated    = true;
         }
 
         if (updated)
            column.rms = std::clamp(column.rms, column.min, column.max);
      }
 
      if (samplesLeft != 0)
      {
         ++columnIndex;
         break;
      }
   }
 
   element.AvailableColumns = columnIndex;
   element.IsComplete       = processedSamples == elementSamplesCount;
 
   return processedSamples != 0;
}

References WaveCacheElement::AvailableColumns, GraphicsDataCacheBase::CacheElementWidth, WaveCacheSampleBlock::ContainsSample(), FrameStatistics::CreateStopwatch(), WaveCacheElement::Data, WaveCacheSampleBlock::DataType, GraphicsDataCacheBase::GetScaledSampleRate(), WaveCacheSampleBlock::GetSummary(), GraphicsDataCacheElementBase::IsComplete, key, WaveCacheSampleBlock::Summary::Max, mCachedBlock, WaveCacheSampleBlock::Summary::Min, WaveCacheSampleBlock::MinMaxRMS256, WaveCacheSampleBlock::MinMaxRMS64k, mProvider, WaveCacheSampleBlock::Reset(), fast_float::round(), WaveCacheSampleBlock::Samples, WaveCacheSampleBlock::Summary::SamplesCount, staffpad::audio::simd::sqrt(), WaveCacheSampleBlock::Summary::SquaresSum, WaveCacheSampleBlock::Summary::SumItemsCount, and FrameStatistics::WaveDataCache.

Here is the call graph for this function:

Member Data Documentation

mCachedBlock

WaveCacheSampleBlock WaveDataCache::mCachedBlock

private

Definition at line 106 of file WaveDataCache.h.

Referenced by InitializeElement().

mProvider

DataProvider WaveDataCache::mProvider

private

Definition at line 104 of file WaveDataCache.h.

Referenced by InitializeElement().

mStretchChangedSubscription

Observer::Subscription WaveDataCache::mStretchChangedSubscription

private

Definition at line 109 of file WaveDataCache.h.

mWaveClip

const WaveClip& WaveDataCache::mWaveClip

private

Definition at line 108 of file WaveDataCache.h.

---

The documentation for this class was generated from the following files:

• WaveDataCache.h
• WaveDataCache.cpp