juce::AudioThumbnailCache Class Reference

An instance of this class is used to manage multiple AudioThumbnail objects. More...

#include <juce_AudioThumbnailCache.h>

Collaboration diagram for juce::AudioThumbnailCache:

Public Member Functions
	AudioThumbnailCache (int maxNumThumbsToStore)
	Creates a cache object.
virtual	~AudioThumbnailCache ()
	Destructor.
void	clear ()
	Clears out any stored thumbnails.
TimeSliceThread &	getTimeSliceThread () noexcept
	Returns the thread that client thumbnails can use.
bool	loadThumb (AudioThumbnailBase &thumb, int64 hashCode)
	Reloads the specified thumb if this cache contains the appropriate stored data.
bool	readFromStream (InputStream &source)
	Attempts to re-load a saved cache of thumbnails from a stream.
void	removeThumb (int64 hashCode)
	Tells the cache to forget about the thumb with the given hashcode.
void	storeThumb (const AudioThumbnailBase &thumb, int64 hashCode)
	Stores the cacheable data from the specified thumb in this cache.
void	writeToStream (OutputStream &stream)
	Writes all currently-loaded cache data to a stream.

Protected Member Functions
virtual bool	loadNewThumb (AudioThumbnailBase &, int64 hashCode)
	This can be overridden to provide a custom callback for loading thumbnails from pre-saved files to save the cache the trouble of having to create them.
virtual void	saveNewlyFinishedThumbnail (const AudioThumbnailBase &, int64 hashCode)
	This can be overridden to provide a custom callback for saving thumbnails once they have finished being loaded.

Private Member Functions
int	findOldestThumb () const
ThumbnailCacheEntry *	findThumbFor (int64 hash) const

Private Attributes
CriticalSection	lock
int	maxNumThumbsToStore
TimeSliceThread	thread
OwnedArray< ThumbnailCacheEntry >	thumbs

Detailed Description

An instance of this class is used to manage multiple AudioThumbnail objects.

The cache runs a single background thread that is shared by all the thumbnails that need it, and it maintains a set of low-res previews in memory, to avoid having to re-scan audio files too often.

See also

AudioThumbnail

@tags{Audio}

Constructor & Destructor Documentation

AudioThumbnailCache()

juce::AudioThumbnailCache::AudioThumbnailCache ( int  maxNumThumbsToStore )

explicit

Creates a cache object.

The maxNumThumbsToStore parameter lets you specify how many previews should be kept in memory at once.

~AudioThumbnailCache()

virtual juce::AudioThumbnailCache::~AudioThumbnailCache ( )

virtual

Destructor.

Member Function Documentation

clear()

void juce::AudioThumbnailCache::clear

(

)

Clears out any stored thumbnails.

findOldestThumb()

int juce::AudioThumbnailCache::findOldestThumb ( ) const

private

findThumbFor()

ThumbnailCacheEntry * juce::AudioThumbnailCache::findThumbFor ( int64  hash ) const

private

getTimeSliceThread()

TimeSliceThread & juce::AudioThumbnailCache::getTimeSliceThread ( )

inlinenoexcept

Returns the thread that client thumbnails can use.

loadNewThumb()

virtual bool juce::AudioThumbnailCache::loadNewThumb ( AudioThumbnailBase &  , int64  hashCode  )

protectedvirtual

This can be overridden to provide a custom callback for loading thumbnails from pre-saved files to save the cache the trouble of having to create them.

loadThumb()

bool juce::AudioThumbnailCache::loadThumb	(	AudioThumbnailBase &	thumb,
		int64	hashCode
	)

Reloads the specified thumb if this cache contains the appropriate stored data.

This is called automatically by the AudioThumbnail class, so you shouldn't normally need to call it directly.

readFromStream()

bool juce::AudioThumbnailCache::readFromStream

(

InputStream &

source

)

Attempts to re-load a saved cache of thumbnails from a stream.

The cache data must have been written by the writeToStream() method. This will replace all currently-loaded thumbnails with the new data.

removeThumb()

void juce::AudioThumbnailCache::removeThumb

(

int64

hashCode

)

Tells the cache to forget about the thumb with the given hashcode.

saveNewlyFinishedThumbnail()

virtual void juce::AudioThumbnailCache::saveNewlyFinishedThumbnail ( const AudioThumbnailBase &  , int64  hashCode  )

protectedvirtual

This can be overridden to provide a custom callback for saving thumbnails once they have finished being loaded.

storeThumb()

void juce::AudioThumbnailCache::storeThumb	(	const AudioThumbnailBase &	thumb,
		int64	hashCode
	)

Stores the cacheable data from the specified thumb in this cache.

This is called automatically by the AudioThumbnail class, so you shouldn't normally need to call it directly.

writeToStream()

void juce::AudioThumbnailCache::writeToStream

(

OutputStream &

stream

)

Writes all currently-loaded cache data to a stream.

The resulting data can be re-loaded with readFromStream().

Member Data Documentation

lock

CriticalSection juce::AudioThumbnailCache::lock

private

maxNumThumbsToStore

int juce::AudioThumbnailCache::maxNumThumbsToStore

private

thread

TimeSliceThread juce::AudioThumbnailCache::thread

private

thumbs

OwnedArray<ThumbnailCacheEntry> juce::AudioThumbnailCache::thumbs

private

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

• juce_AudioThumbnailCache.h