/**
* Copyright (C) 2008 Sly Technologies, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
package com.slytechs.jnetstream.packet;
import org.jnetstream.packet.DataField;
import com.slytechs.utils.crypto.Crc16;
import com.slytechs.utils.memory.BitBuffer;
import com.slytechs.utils.net.EUI48;
import com.slytechs.utils.net.Ip4Address;
/**
* @author Mark Bednarczyk
* @author Sly Technologies, Inc.
*
*/
public abstract class AbstractData {
protected BitBuffer bits;
protected int offset;
public AbstractData(BitBuffer bits, int offset) {
this.bits = bits;
this.offset = offset;
}
protected byte readByte(int length) {
return (byte) bits.getBits(offset, length);
}
protected byte readByte(DataField field) {
return (byte) bits.getBits(offset + field.getOffset(), field.getLength());
}
protected int readInt(int length) {
return bits.getBits(offset, length);
}
protected int readInt(DataField field) {
return bits.getBits(offset + field.getOffset(), field.getLength());
}
protected short readShort(int length) {
return (short) bits.getBits(offset, length);
}
protected short readShort(DataField field) {
return (short) bits.getBits(offset + field.getOffset(), field.getLength());
}
protected Crc16 readCrc16() {
return new Crc16(bits.getBits(offset, 16));
}
protected Crc16 readCrc16(DataField field) {
return new Crc16(bits.getBits(offset + field.getOffset(), field.getLength()));
}
protected byte[] readByteArray(DataField field) {
final byte[] b = new byte[field.getLength() / 8];
bits.get(offset + field.getOffset(), b);
return b;
}
protected EUI48 readEUI48() {
final byte[] b = new byte[6];
bits.get(offset, b);
return new EUI48(b);
}
protected EUI48 readEUI48(DataField field) {
final byte[] b = new byte[field.getLength() / 8];
bits.get(offset + field.getOffset(), b);
return new EUI48(b);
}
protected Ip4Address readIp4Address() {
final byte[] b = new byte[4];
bits.get(offset, b);
return new Ip4Address(b);
}
protected Ip4Address readIp4Address(DataField field) {
final byte[] b = new byte[field.getLength() / 8];
bits.get(offset + field.getOffset(), b);
return new Ip4Address(b);
}
protected byte[] readByteArray(DataField field, byte[] b) {
bits.get(offset + field.getOffset(), b);
return b;
}
public int getOffset() {
return this.offset;
}
public Object toUnsigned(Object value) {
if (value instanceof Byte) {
return (((Number) value).intValue() & 0xFF);
} else if (value instanceof Short) {
return (((Number) value).intValue() & 0xFFFF);
} else if (value instanceof Integer) {
return (((Number) value).longValue() & 0xFFFFFFFFL);
}
return value;
}
}