view data/fft/FFTFileCacheReader.h @ 537:3cc4b7cd2aa5

* Merge from one-fftdataserver-per-fftmodel branch.  This bit of
reworking (which is not described very accurately by the title of
the branch) turns the MatrixFile object into something that either
reads or writes, but not both, and separates the FFT file cache
reader and writer implementations separately.  This allows the
FFT data server to have a single thread owning writers and one reader
per "customer" thread, and for all locking to be vastly simplified
and concentrated in the data server alone (because none of the
classes it makes use of is used in more than one thread at a time).
The result is faster and more trustworthy code.

/* -*- 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 2006-2009 Chris Cannam and QMUL.
    
    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_READER_H_
#define _FFT_FILE_CACHE_READER_H_

#include "data/fileio/MatrixFile.h"
#include "FFTCacheReader.h"
#include "FFTCacheStorageType.h"

class FFTFileCacheWriter;

class FFTFileCacheReader : public FFTCacheReader
{
public:
    FFTFileCacheReader(FFTFileCacheWriter *);
    ~FFTFileCacheReader();

    size_t getWidth() const;
    size_t getHeight() const;
	
    float getMagnitudeAt(size_t x, size_t y) const;
    float getNormalizedMagnitudeAt(size_t x, size_t y) const;
    float getMaximumMagnitudeAt(size_t x) const;
    float getPhaseAt(size_t x, size_t y) const;

    void getValuesAt(size_t x, size_t y, float &real, float &imag) const;
    void getMagnitudesAt(size_t x, float *values, size_t minbin, size_t count, size_t step) const;

    bool haveSetColumnAt(size_t x) const;

    static size_t getCacheSize(size_t width, size_t height,
                               FFTCache::StorageType type);

    FFTCache::StorageType getStorageType() const { return m_storageType; }

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

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

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

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

    void populateReadBuf(size_t x) const;

    float getNormalizationFactor(size_t col) const {
        size_t h = m_mfc->getHeight();
        if (h < m_factorSize) return 0;
        if (m_storageType != FFTCache::Compact) {
            return getFromReadBufStandard(col, h - 1);
        } else {
            union {
                float f;
                uint16_t u[2];
            } factor;
            if (!m_readbuf ||
                !(m_readbufCol == col ||
                  (m_readbufWidth > 1 && m_readbufCol+1 == col))) {
                populateReadBuf(col);
            }
            size_t ix = (col - m_readbufCol) * m_mfc->getHeight() + h;
            factor.u[0] = ((uint16_t *)m_readbuf)[ix - 2];
            factor.u[1] = ((uint16_t *)m_readbuf)[ix - 1];
            return factor.f;
        }
    }
 
    FFTCache::StorageType m_storageType;
    size_t m_factorSize;
    MatrixFile *m_mfc;
};

#endif