view data/fft/FFTFileCache.h @ 168:04baa690f90d

* Start adding StorageAdviser class to determine whether caches should be
  on disc or in memory

/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */

/*
    Sonic Visualiser
    An audio file viewer and annotation editor.
    Centre for Digital Music, Queen Mary, University of London.
    This file copyright 2006 Chris Cannam.
    
    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 _FFT_FILE_CACHE_H_
#define _FFT_FILE_CACHE_H_

#include "FFTCache.h"
#include "fileio/MatrixFile.h"

#include <QMutex>

class FFTFileCache : public FFTCache
{
public:
    enum StorageType {
        Compact, // 16 bits normalized polar
        Rectangular, // floating point real+imag
        Polar, // floating point mag+phase
    };

    FFTFileCache(QString fileBase, MatrixFile::Mode mode,
                 StorageType storageType);
    virtual ~FFTFileCache();

    MatrixFile::Mode getMode() const { return m_mfc->getMode(); }

    virtual size_t getWidth() const;
    virtual size_t getHeight() const;
	
    virtual void resize(size_t width, size_t height);
    virtual void reset(); // zero-fill or 1-fill as appropriate without changing size
	
    virtual float getMagnitudeAt(size_t x, size_t y) const;
    virtual float getNormalizedMagnitudeAt(size_t x, size_t y) const;
    virtual float getMaximumMagnitudeAt(size_t x) const;
    virtual float getPhaseAt(size_t x, size_t y) const;

    virtual void getValuesAt(size_t x, size_t y, float &real, float &imag) const;

    virtual bool haveSetColumnAt(size_t x) const;

    virtual void setColumnAt(size_t x, float *mags, float *phases, float factor);
    virtual void setColumnAt(size_t x, float *reals, float *imags);

    virtual void suspend() { m_mfc->suspend(); }

protected:
    char *m_writebuf;
    mutable char *m_readbuf;
    mutable size_t m_readbufCol;
    mutable size_t m_readbufWidth;

    float getFromReadBufStandard(size_t x, size_t y) const {
        if (m_readbuf &&
            (m_readbufCol == x || (m_readbufWidth > 1 && m_readbufCol+1 == x))) {
            return ((float *)m_readbuf)[(x - m_readbufCol) * m_mfc->getHeight() + y];
        } else {
            populateReadBuf(x);
            return getFromReadBufStandard(x, y);
        }
    }

    float getFromReadBufCompactUnsigned(size_t x, size_t y) const {
        if (m_readbuf &&
            (m_readbufCol == x || (m_readbufWidth > 1 && m_readbufCol+1 == x))) {
            return ((uint16_t *)m_readbuf)[(x - m_readbufCol) * m_mfc->getHeight() + y];
        } else {
            populateReadBuf(x);
            return getFromReadBufCompactUnsigned(x, y);
        }
    }

    float getFromReadBufCompactSigned(size_t x, size_t y) const {
        if (m_readbuf &&
            (m_readbufCol == x || (m_readbufWidth > 1 && m_readbufCol+1 == x))) {
            return ((int16_t *)m_readbuf)[(x - m_readbufCol) * m_mfc->getHeight() + y];
        } else {
            populateReadBuf(x);
            return getFromReadBufCompactSigned(x, y);
        }
    }

    void populateReadBuf(size_t x) const {
        if (!m_readbuf) {
            m_readbuf = new char[m_mfc->getHeight() * 2 * m_mfc->getCellSize()];
        }
        m_mfc->getColumnAt(x, m_readbuf);
        if (m_mfc->haveSetColumnAt(x + 1)) {
            m_mfc->getColumnAt
                (x + 1, m_readbuf + m_mfc->getCellSize() * m_mfc->getHeight());
            m_readbufWidth = 2;
        } else {
            m_readbufWidth = 1;
        }
        m_readbufCol = x;
    }

    float getNormalizationFactor(size_t col) const {
        if (m_storageType != Compact) {
            return getFromReadBufStandard(col, m_mfc->getHeight() - 1);
        } else {
            float factor;
            factor = getFromReadBufCompactUnsigned(col, m_mfc->getHeight() - 1);
            return factor / 65535.0;
        }
    }

    MatrixFile *m_mfc;
    QMutex m_writeMutex;
    StorageType m_storageType;
};

#endif