view data/fileio/BZipFileDevice.cpp @ 490:c3fb8258e34d

* Make it possible to import an entire session from an RDF document.
  However, at the moment the timings of events appear to be constrained
  by how far the audio decoder has got through its audio file at the
  time the event is queried -- need to investigate.

/* -*- 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.
*/

#include "BZipFileDevice.h"

#include <bzlib.h>

#include <iostream>

BZipFileDevice::BZipFileDevice(QString fileName) :
    m_fileName(fileName),
    m_file(0),
    m_bzFile(0),
    m_atEnd(true),
    m_ok(true)
{
}

BZipFileDevice::~BZipFileDevice()
{
//    std::cerr << "BZipFileDevice::~BZipFileDevice(" << m_fileName.toStdString() << ")" << std::endl;
    if (m_bzFile) close();
}

bool
BZipFileDevice::isOK() const
{
    return m_ok;
}

bool
BZipFileDevice::open(OpenMode mode)
{
    setErrorString("");

    if (m_bzFile) {
        setErrorString(tr("File is already open"));
        return false;
    }

    if (mode & Append) {
        setErrorString(tr("Append mode not supported"));
        m_ok = false;
        return false;
    }

    if ((mode & (ReadOnly | WriteOnly)) == 0) {
        setErrorString(tr("File access mode not specified"));
        m_ok = false;
        return false;
    }

    if ((mode & ReadOnly) && (mode & WriteOnly)) {
        setErrorString(tr("Read and write modes both specified"));
        m_ok = false;
        return false;
    }

    if (mode & WriteOnly) {

        m_file = fopen(m_fileName.toLocal8Bit().data(), "wb");
        if (!m_file) {
            setErrorString(tr("Failed to open file for writing"));
            m_ok = false;
            return false;
        }

        int bzError = BZ_OK;
        m_bzFile = BZ2_bzWriteOpen(&bzError, m_file, 9, 0, 0);

        if (!m_bzFile) {
            fclose(m_file);
            m_file = 0;
            setErrorString(tr("Failed to open bzip2 stream for writing"));
            m_ok = false;
            return false;
        }

//        std::cerr << "BZipFileDevice: opened \"" << m_fileName.toStdString() << "\" for writing" << std::endl;

        setErrorString(QString());
        setOpenMode(mode);
        return true;
    }

    if (mode & ReadOnly) {

        m_file = fopen(m_fileName.toLocal8Bit().data(), "rb");
        if (!m_file) {
            setErrorString(tr("Failed to open file for reading"));
            m_ok = false;
            return false;
        }

        int bzError = BZ_OK;
        m_bzFile = BZ2_bzReadOpen(&bzError, m_file, 0, 0, NULL, 0);

        if (!m_bzFile) {
            fclose(m_file);
            m_file = 0;
            setErrorString(tr("Failed to open bzip2 stream for reading"));
            m_ok = false;
            return false;
        }

//        std::cerr << "BZipFileDevice: opened \"" << m_fileName.toStdString() << "\" for reading" << std::endl;

        m_atEnd = false;

        setErrorString(QString());
        setOpenMode(mode);
        return true;
    }

    setErrorString(tr("Internal error (open for neither read nor write)"));
    m_ok = false;
    return false;
}

void
BZipFileDevice::close()
{
    if (!m_bzFile) {
        setErrorString(tr("File not open"));
        m_ok = false;
        return;
    }

    int bzError = BZ_OK;

    if (openMode() & WriteOnly) {
        unsigned int in = 0, out = 0;
        BZ2_bzWriteClose(&bzError, m_bzFile, 0, &in, &out);
//	std::cerr << "Wrote bzip2 stream (in=" << in << ", out=" << out << ")" << std::endl;
	if (bzError != BZ_OK) {
	    setErrorString(tr("bzip2 stream write close error"));
	}
        fclose(m_file);
        m_bzFile = 0;
        m_file = 0;
        m_ok = false;
        return;
    }

    if (openMode() & ReadOnly) {
        BZ2_bzReadClose(&bzError, m_bzFile);
        if (bzError != BZ_OK) {
            setErrorString(tr("bzip2 stream read close error"));
        }
        fclose(m_file);
        m_bzFile = 0;
        m_file = 0;
        m_ok = false;
        return;
    }

    setErrorString(tr("Internal error (close for neither read nor write)"));
    return;
}

qint64
BZipFileDevice::readData(char *data, qint64 maxSize)
{
    if (m_atEnd) return 0;

    int bzError = BZ_OK;
    int read = BZ2_bzRead(&bzError, m_bzFile, data, maxSize);

//    std::cerr << "BZipFileDevice::readData: requested " << maxSize << ", read " << read << std::endl;

    if (bzError != BZ_OK) {
        if (bzError != BZ_STREAM_END) {
            std::cerr << "BZipFileDevice::readData: error condition" << std::endl;
            setErrorString(tr("bzip2 stream read error"));
            m_ok = false;
            return -1;
        } else {
//            std::cerr << "BZipFileDevice::readData: reached end of file" << std::endl;
            m_atEnd = true;
        }            
    }

    return read;
}

qint64
BZipFileDevice::writeData(const char *data, qint64 maxSize)
{
    int bzError = BZ_OK;
    BZ2_bzWrite(&bzError, m_bzFile, (void *)data, maxSize);

//    std::cerr << "BZipFileDevice::writeData: " << maxSize << " to write" << std::endl;

    if (bzError != BZ_OK) {
        std::cerr << "BZipFileDevice::writeData: error condition" << std::endl;
        setErrorString("bzip2 stream write error");
        m_ok = false;
        return -1;
    }

//    std::cerr << "BZipFileDevice::writeData: wrote " << maxSize << std::endl;

    return maxSize;
}