view data/fileio/BZipFileDevice.cpp @ 1833:21c792334c2e sensible-delimited-data-strings

Rewrite all the DelimitedDataString stuff so as to return vectors of individual cell strings rather than having the classes add the delimiters themselves. Rename accordingly to names based on StringExport. Take advantage of this in the CSV writer code so as to properly quote cells that contain delimiter characters.

/* -*- 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>

#include "base/Debug.h"

// for dup:
#ifdef _MSC_VER
#include <io.h>
#else
#include <unistd.h>
#endif

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

BZipFileDevice::~BZipFileDevice()
{
//    SVDEBUG << "BZipFileDevice::~BZipFileDevice(" << m_fileName << ")" << 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;
    }

    // This is all going to be a bit silly.
    //
    // We open the file with QFile so as not to have to worry about locale
    // support ourselves (especially on Windows). Then we get a fd from
    // QFile and "convert" it to a FILE* using fdopen because that is what
    // the bz2 library needs for reading and writing an already-open file.
    //
    // fdopen takes over the fd it is given, and will close it when fclose
    // is called. (We must call fclose, because it's needed to avoid
    // leaking the file stream structure.)
    //
    // But QFile will also close its fd, either when we call QFile::close
    // or on destruction -- there doesn't seem to be a way to avoid that
    // for a file that QFile opened.
    //
    // So we have to add an extra dup() in to the fdopen to avoid a double
    // close.
    //
    // Note that bz2 will *not* fclose the FILE* it was passed, so we
    // don't have a problem with calling both bzWriteClose and fclose.

    if (mode & WriteOnly) {

        if (!m_qfile.open(QIODevice::WriteOnly)) {
            setErrorString(tr("Failed to open file for writing"));
            m_ok = false;
            return false;
        }
        
        m_file = fdopen(dup(m_qfile.handle()), "wb");
        if (!m_file) {
            setErrorString(tr("Failed to open file handle for writing"));
            m_qfile.close();
            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 = nullptr;
            m_qfile.close();
            setErrorString(tr("Failed to open bzip2 stream for writing"));
            m_ok = false;
            return false;
        }

//        cerr << "BZipFileDevice: opened \"" << m_fileName << "\" for writing" << endl;

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

    if (mode & ReadOnly) {

        if (!m_qfile.open(QIODevice::ReadOnly)) {
            setErrorString(tr("Failed to open file for reading"));
            m_ok = false;
            return false;
        }
        
        m_file = fdopen(dup(m_qfile.handle()), "rb");
        if (!m_file) {
            setErrorString(tr("Failed to open file handle for reading"));
            m_ok = false;
            return false;
        }

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

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

//        cerr << "BZipFileDevice: opened \"" << m_fileName << "\" for reading" << 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);
//        cerr << "Wrote bzip2 stream (in=" << in << ", out=" << out << ")" << endl;
        if (bzError != BZ_OK) {
            setErrorString(tr("bzip2 stream write close error"));
        }
        fclose(m_file);
        m_qfile.close();
        m_bzFile = nullptr;
        m_file = nullptr;
        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_qfile.close();
        m_bzFile = nullptr;
        m_file = nullptr;
        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, int(maxSize));

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

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

//    SVDEBUG << "BZipFileDevice::writeData: " << maxSize << " to write" << endl;

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

//    SVDEBUG << "BZipFileDevice::writeData: wrote " << maxSize << endl;

    return maxSize;
}