view base/TempWriteFile.cpp @ 1008:d9e0e59a1581

When using an aggregate model to pass data to a transform, zero-pad the shorter input to the duration of the longer rather than truncating the longer. (This is better behaviour for e.g. MATCH, and in any case the code was previously truncating incorrectly and ending up with garbage data at the end.)

/* -*- 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 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 "TempWriteFile.h"

#include "Exceptions.h"

#include <QTemporaryFile>
#include <QDir>
#include <iostream>

TempWriteFile::TempWriteFile(QString target) :
    m_target(target)
{
    QTemporaryFile temp(m_target + ".");
    temp.setAutoRemove(false);
    temp.open(); // creates the file and opens it atomically
    if (temp.error()) {
	cerr << "TempWriteFile: Failed to create temporary file in directory of " << m_target << ": " << temp.errorString() << endl;
	throw FileOperationFailed(temp.fileName(), "creation");
    }
    
    m_temp = temp.fileName();
    temp.close(); // does not remove the file
}

TempWriteFile::~TempWriteFile()
{
    if (m_temp != "") {
	QDir dir(QFileInfo(m_temp).dir());
	dir.remove(m_temp);
    }
}

QString
TempWriteFile::getTemporaryFilename()
{
    return m_temp;
}

void
TempWriteFile::moveToTarget()
{
    if (m_temp == "") return;

    QDir dir(QFileInfo(m_temp).dir());
    // According to  http://doc.trolltech.com/4.4/qdir.html#rename
    // some systems fail, if renaming over an existing file.
    // Therefore, delete first the existing file.
    if (dir.exists(m_target)) dir.remove(m_target);
    if (!dir.rename(m_temp, m_target)) {
	cerr << "TempWriteFile: Failed to rename temporary file " << m_temp << " to target " << m_target << endl;
	throw FileOperationFailed(m_temp, "rename");
    }

    m_temp = "";
}