hashtags/lmms
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases 1 Wiki Activity

MMP: write to temporary file first and then rename

Browse Source 
In order to avoid data loss because of full disks or other storage
failures write a temporary file first, rename current file to backup
file and rename temporary file to current file.

Closes #26.
This commit is contained in:
Tobias Doerffel
2014-01-20 22:34:42 +01:00
parent f0d6d44545
commit 67b99ac48f
1 changed files with 29 additions and 16 deletions
Download Patch File Download Diff File Expand all files Collapse all files

45
src/core/mmp.cpp
View File

@@ -1,7 +1,7 @@
/*
* mmp.cpp - implementation of class multimediaProject
*
* Copyright (c) 2004-2009 Tobias Doerffel <tobydox/at/users.sourceforge.net>
* Copyright (c) 2004-2014 Tobias Doerffel <tobydox/at/users.sourceforge.net>
* Copyright (c) 2012-2013 Paul Giblock <p/at/pgiblock.net>
*
* This file is part of Linux MultiMedia Studio - http://lmms.sourceforge.net
@@ -30,6 +30,7 @@
#include <QtCore/QDebug>
#include <QtCore/QFile>
#include <QtCore/QFileInfo>
#include <QtCore/QTextStream>
#include <QtGui/QMessageBox>
@@ -179,27 +180,25 @@ void multimediaProject::write( QTextStream & _strm )
bool multimediaProject::writeFile( const QString & _fn )
bool multimediaProject::writeFile( const QString& filename )
{
QString fn = nameWithExtension( _fn );
QFile outfile( fn );
const QString fullName = nameWithExtension( filename );
const QString fullNameTemp = fullName + ".new";
const QString fullNameBak = fullName + ".bak";
QFile outfile( fullNameTemp );
if( !outfile.open( QIODevice::WriteOnly | QIODevice::Truncate ) )
{
QMessageBox::critical( NULL,
songEditor::tr( "Could not write file" ),
songEditor::tr( "Could not write file "
"%1. You probably are "
"not permitted to "
"write to this file.\n"
"Please make sure you "
"have write-access to "
"the file and try "
"again."
).arg( fn ) );
songEditor::tr( "Could not write file" ),
songEditor::tr( "Could not open %1 for writing. You probably are not permitted to "
"write to this file. Please make sure you have write-access to "
"the file and try again." ).arg( fullName ) );
return false;
}
if( fn.section( '.', -1 ) == "mmpz" )
if( fullName.section( '.', -1 ) == "mmpz" )
{
QString xml;
QTextStream ts( &xml );
@@ -211,9 +210,23 @@ bool multimediaProject::writeFile( const QString & _fn )
QTextStream ts( &outfile );
write( ts );
}
outfile.close();
return true;
// make sure the file has been written correctly
if( QFileInfo( outfile.fileName() ).size() > 0 )
{
// remove old backup file
QFile::remove( fullNameBak );
// move current file to backup file
QFile::rename( fullName, fullNameBak );
// move temporary file to current file
QFile::rename( fullNameTemp, fullName );
return true;
}
return false;
}