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/*-
* Copyright (C) 2006 Erik Larsson
*
* All rights reserved.
*
* 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.
*
* 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, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
*/
package org.catacombae.rarx;
import java.io.PrintStream;
import java.util.zip.CRC32;
public abstract class RARHeader {
/*
* Common fields for all RAR headers
* size: 7 bytes
*
* BP Size Description
* 0 2 HeadCRC
* 2 1 HeadType
* 3 2 Flags
* 5 2 HeadSize
*/
// Possible values for the fields headType in various classes
//public static final int ALL_HEAD = 0;
public static final int MARK_HEAD = 0x72; // 0x69 for UniquE! ones..? However, this field isn't really needed.
public static final int MAIN_HEAD = 0x73;
public static final int FILE_HEAD = 0x74;
public static final int COMM_HEAD = 0x75;
public static final int AV_HEAD = 0x76;
public static final int SUB_HEAD = 0x77;
public static final int PROTECT_HEAD = 0x78;
public static final int COMMENT_HEAD = 0x7a;
public static final int EOF_HEAD = 0x7b;
/* The versioning seems very simple. version 2.0 is represented
by the value 20 (0x14), 2.6 by the value 26 (0x1a) etc. */
public static final int UNPACK_VERSION_2_0 = 0x14;
public static final int UNPACK_VERSION_2_6 = 0x1a; // efterlyst-bfc.rar
public static final int UNPACK_VERSION_2_9 = 0x1d;
public static final int METHOD_UNCOMPRESSED = 0x30; // Observerad i 2.0, 2.9
public static final int METHOD_COMPRESSION_1 = 0x35; // Observerad i 2.0, 2.9
public static final int METHOD_COMPRESSION_2 = 0x33; // Observerad i 2.0 (flera g�nger, men ovanligt), 2.9
/* Hypotes: de tv� minst signifikanta bitarna i Flags indikerar om en fil
forts�tter p� nytt medium. Om bit 0 �r satt �r den aktuella filen en
forts�ttning p� en tidigare fil. Om bit 1 �r satt forts�tter den
aktuella filen p� ytterligare nya media.
Hypotes bekr�ftad. */
private final byte[] headCRC = new byte[2];
private final byte[] headType = new byte[1];
private final byte[] flags = new byte[2];
private final byte[] headSize = new byte[2];
private final CRC32 crc = new CRC32();
public RARHeader(byte[] data, int offset) {
System.arraycopy(data, offset+0, headCRC, 0, 2);
System.arraycopy(data, offset+2, headType, 0, 1);
System.arraycopy(data, offset+3, flags, 0, 2);
System.arraycopy(data, offset+5, headSize, 0, 2);
}
public int getSize() { return _getSize(); }
private int _getSize() { return 7; }
protected void validateData() {
if(calculateHeadCRC() != getHeadCRC())
throw new InvalidDataException("Incorrect header CRC!");
}
public short getHeadCRC() { return Util.readShortLE(headCRC); }
public byte getHeadType() { return Util.readByteLE(headType); }
public short getFlags() { return Util.readShortLE(flags); }
public short getHeadSize() { return Util.readShortLE(headSize); }
public boolean getFlag(int bitNumber) {
return Util.getBit(getFlags(), bitNumber);//((getFlags() >> byteNumber) & 0x1) == 0x1;
}
public byte[] getHeaderData() {
byte[] data = new byte[_getSize()];
System.arraycopy(headCRC, 0, data, 0, headCRC.length);
System.arraycopy(headType, 0, data, 2, headType.length);
System.arraycopy(flags, 0, data, 3, flags.length);
System.arraycopy(headSize, 0, data, 5, headSize.length);
return data;
}
public short calculateHeadCRC() {
crc.reset();
crc.update(getHeaderData(), 2, getSize()-2);
return (short)(crc.getValue());
}
protected void printFields(PrintStream ps, String prefix) {
ps.println(prefix + " HeadCRC: " + Util.toHexStringBE(getHeadCRC()));
if(calculateHeadCRC() != getHeadCRC())
ps.println(prefix + " CHECKSUMS NOT MATCHING! (0x" +
Util.toHexStringBE(getHeadCRC()) + " != 0x" +
Util.toHexStringBE(calculateHeadCRC()) + "))");
ps.println(prefix + " HeadType: " + Util.toHexStringBE(getHeadType()));
ps.println(prefix + " Flags: " + Util.toHexStringBE(getFlags()));
ps.println(prefix + " HeadSize: " + getHeadSize() + " bytes");
}
}
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