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/*
Rosegarden
A sequencer and musical notation editor.
This program is Copyright 2000-2008
Guillaume Laurent <[email protected]>,
Chris Cannam <[email protected]>,
Richard Bown <[email protected]>
The moral right of the authors to claim authorship of this work
has been asserted.
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version. See the file
COPYING included with this distribution for more information.
*/
#ifndef _AUDIO_CACHE_H_
#define _AUDIO_CACHE_H_
#include <cstddef>
#include <map>
namespace Rosegarden
{
/**
* A simple cache for smallish bits of audio data, indexed by some
* opaque pointer type. (The PlayableAudioFile uses this with an
* AudioFile* index type, for example.) With reference counting.
*/
class AudioCache
{
public:
AudioCache() { }
virtual ~AudioCache();
/**
* Look some audio data up in the cache and report whether it
* exists.
*/
bool has(void *index);
/**
* Look some audio data up in the cache and return it if it
* exists, returning the number of channels in channels, the frame
* count in frames, and one pointer per channel to samples in the
* return value. Return 0 if the data is not in cache. Does not
* affect the reference count. Ownership of the returned data
* remains with the cache object. You should not call this unless
* you have already called incrementReference (or addData) to
* register your interest.
*/
float **getData(void *index, size_t &channels, size_t &frames);
/**
* Add a piece of data to the cache, and increment the reference
* count for that data (to 1). Ownership of the data is passed
* to the cache, which will delete it with delete[] when done.
*/
void addData(void *index, size_t channels, size_t nframes, float **data);
/**
* Increment the reference count for a given piece of data.
*/
void incrementReference(void *index);
/**
* Decrement the reference count for a given piece of data,
* and delete the data from the cache if the reference count has
* reached zero.
*/
void decrementReference(void *index);
protected:
void clear();
struct CacheRec {
CacheRec() : data(0), channels(0), nframes(0), refCount(0) { }
CacheRec(float **d, size_t c, size_t n) :
data(d), channels(c), nframes(n), refCount(1) { }
~CacheRec();
float **data;
size_t channels;
size_t nframes;
int refCount;
};
std::map<void *, CacheRec *> m_cache;
};
}
#endif
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