AudioThumbnailCache Class Reference

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

#include <juce_AudioThumbnailCache.h>

Collaboration diagram for AudioThumbnailCache:

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

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. More...
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. More...

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

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

Friends
struct	ContainerDeletePolicy< ThumbnailCacheEntry >

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

Constructor & Destructor Documentation

AudioThumbnailCache()

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 AudioThumbnailCache::~AudioThumbnailCache ( )

virtual

Destructor.

Member Function Documentation

clear()

void AudioThumbnailCache::clear

(

)

Clears out any stored thumbnails.

findOldestThumb()

int AudioThumbnailCache::findOldestThumb ( ) const

private

findThumbFor()

ThumbnailCacheEntry* AudioThumbnailCache::findThumbFor ( int64  hash ) const

private

getTimeSliceThread()

TimeSliceThread& AudioThumbnailCache::getTimeSliceThread ( )

inlinenoexcept

Returns the thread that client thumbnails can use.

loadNewThumb()

virtual bool 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 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 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 AudioThumbnailCache::removeThumb

(

int64

hashCode

)

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

saveNewlyFinishedThumbnail()

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

Stores the cachable 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 AudioThumbnailCache::writeToStream

(

OutputStream &

stream

)

Writes all currently-loaded cache data to a stream.

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

Friends And Related Function Documentation

ContainerDeletePolicy< ThumbnailCacheEntry >

friend struct ContainerDeletePolicy< ThumbnailCacheEntry >

friend

Member Data Documentation

lock

CriticalSection AudioThumbnailCache::lock

private

maxNumThumbsToStore

int AudioThumbnailCache::maxNumThumbsToStore

private

thread

TimeSliceThread AudioThumbnailCache::thread

private

thumbs

OwnedArray<ThumbnailCacheEntry> AudioThumbnailCache::thumbs

private

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

• juce_AudioThumbnailCache.h