package ole;
import pptViewer.PptException;
/**
* File Allocation Table für den Mini-Stream
* @author Michael Roth <michi.ro@gmx.de>
*
* 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 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
public class MiniFat extends StreamReader {
private OleFile file;
int sectorsPerFat;
int fatPerDif;
public MiniFat(OleFile oleFile) {
super (oleFile, oleFile.getHeader().getSecMiniFatStart());
this.file = oleFile;
sectorsPerFat=this.file.getHeader().getSecSize()/4;
fatPerDif=this.file.getHeader().getSecSize()/4-1;
}
/**
* Eintrag in der FAT zu dem gesuchten Sektor
* @param block Der aktuelle Sektor
* @return Position des nachfolgenden Sektors
* @throws PptException Falls die Sektorkette mit dem aktuellen Block endet
*/
public int getNextBlock(int block) throws PptException {
byte[] data;
//System.out.println("Looking for next block for "+block);
data = this.get(block*4, 4);
int sector= (data[0]& 0x0FF)|((data[1]& 0x0FF)<<8)|((data[2]& 0x0FF)<<16)|((data[3]& 0x0FF)<<24);
if (sector == OleFile.ENDOFCHAIN) throw new PptException("EndOfChain");
if (sector == OleFile.DIFSECT) throw new PptException("DifSector");
if (sector == OleFile.FATSECT) throw new PptException("FatSector");
if (sector == OleFile.FREESECT) throw new PptException("FreeSector");
return sector;
}
}