/*
* $Id$
*
* Copyright (C) 2003-2015 JNode.org
*
* 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 org.jnode.util;
/**
* Little endian (LSB first) conversion methods.
*
* @author Ewout Prangsma (epr@users.sourceforge.net)
*/
public class LittleEndian {
/**
* Gets an 8-bit unsigned integer from the given byte array at the given offset.
*
* @param src
* @param offset
*/
public static int getUInt8(byte[] src, int offset) {
return src[offset] & 0xFF;
}
/**
* Gets an 8-bit signed integer from the given byte array at the given offset.
*
* @param src
* @param offset
*/
public static int getInt8(byte[] src, int offset) {
return src[offset];
}
/**
* Gets a 16-bit unsigned integer from the given byte array at the given offset.
*
* @param src
* @param offset
*/
public static int getUInt16(byte[] src, int offset) {
final int v0 = src[offset + 0] & 0xFF;
final int v1 = src[offset + 1] & 0xFF;
return ((v1 << 8) | v0);
}
/**
* Gets a 16-bit signed integer from the given byte array at the given offset.
*
* @param src
* @param offset
*/
public static int getInt16(byte[] src, int offset) {
final int v0 = src[offset + 0] & 0xFF;
final int v1 = src[offset + 1] & 0xFF;
return (short) ((v1 << 8) | v0);
}
/**
* Gets a 24-bit unsigned integer from the given byte array at the given offset.
*
* @param src
* @param offset
*/
public static int getUInt24(byte[] src, int offset) {
final int v0 = src[offset + 0] & 0xFF;
final int v1 = src[offset + 1] & 0xFF;
final int v2 = src[offset + 2] & 0xFF;
return ((v2 << 16) | (v1 << 8) | v0);
}
/**
* Gets a 24-bit signed integer from the given byte array at the given offset.
*
* @param src
* @param offset
*/
public static int getInt24(byte[] src, int offset) {
final int v0 = src[offset + 0] & 0xFF;
final int v1 = src[offset + 1] & 0xFF;
final int v2 = src[offset + 2] & 0xFF;
return ((v2 << 24) | (v1 << 16) | (v0 << 8)) >> 8;
}
/**
* Gets a 32-bit unsigned integer from the given byte array at the given offset.
*
* @param src
* @param offset
*/
public static long getUInt32(byte[] src, int offset) {
final long v0 = src[offset + 0] & 0xFF;
final long v1 = src[offset + 1] & 0xFF;
final long v2 = src[offset + 2] & 0xFF;
final long v3 = src[offset + 3] & 0xFF;
return ((v3 << 24) | (v2 << 16) | (v1 << 8) | v0);
}
/**
* Gets a 32-bit signed integer from the given byte array at the given offset.
*
* @param src
* @param offset
*/
public static int getInt32(byte[] src, int offset) {
final int v0 = src[offset + 0] & 0xFF;
final int v1 = src[offset + 1] & 0xFF;
final int v2 = src[offset + 2] & 0xFF;
final int v3 = src[offset + 3] & 0xFF;
return ((v3 << 24) | (v2 << 16) | (v1 << 8) | v0);
}
/**
* Gets a 48-bit unsigned integer from the given byte array at the given offset.
*
* @param src
* @param offset
*/
public static long getUInt48(byte[] src, int offset) {
final long v0 = src[offset + 0] & 0xFF;
final long v1 = src[offset + 1] & 0xFF;
final long v2 = src[offset + 2] & 0xFF;
final long v3 = src[offset + 3] & 0xFF;
final long v4 = src[offset + 4] & 0xFF;
final long v5 = src[offset + 5] & 0xFF;
return ((v5 << 40) | (v4 << 32) | (v3 << 24) | (v2 << 16) | (v1 << 8) | v0);
}
/**
* Gets a 48-bit signed integer from the given byte array at the given offset.
*
* @param src
* @param offset
*/
public static long getInt48(byte[] src, int offset) {
final long v0 = src[offset + 0] & 0xFF;
final long v1 = src[offset + 1] & 0xFF;
final long v2 = src[offset + 2] & 0xFF;
final long v3 = src[offset + 3] & 0xFF;
final long v4 = src[offset + 4] & 0xFF;
final long v5 = src[offset + 5] & 0xFF;
return ((v5 << 56) | (v4 << 48) | (v3 << 40) | (v2 << 32) | (v1 << 24) | (v0 << 16)) >> 16;
}
/**
* Gets a 64-bit signed integer from the given byte array at the given offset.
*
* @param src
* @param offset
*/
public static long getInt64(byte[] src, int offset) {
final long v0 = src[offset + 0] & 0xFF;
final long v1 = src[offset + 1] & 0xFF;
final long v2 = src[offset + 2] & 0xFF;
final long v3 = src[offset + 3] & 0xFF;
final long v4 = src[offset + 4] & 0xFF;
final long v5 = src[offset + 5] & 0xFF;
final long v6 = src[offset + 6] & 0xFF;
final long v7 = src[offset + 7] & 0xFF;
return ((v7 << 56) | (v6 << 48) | (v5 << 40) | (v4 << 32) | (v3 << 24) | (v2 << 16) | (v1 << 8) | v0);
}
/**
* Sets an 8-bit integer in the given byte array at the given offset.
*/
public static void setInt8(byte[] dst, int offset, int value) {
dst[offset] = (byte) value;
}
/**
* Sets a 16-bit integer in the given byte array at the given offset.
*/
public static void setInt16(byte[] dst, int offset, int value) {
dst[offset + 0] = (byte) (value & 0xFF);
dst[offset + 1] = (byte) ((value >>> 8) & 0xFF);
}
/**
* Sets a 24-bit integer in the given byte array at the given offset.
*/
public static void setInt24(byte[] dst, int offset, int value) {
dst[offset + 0] = (byte) (value & 0xFF);
dst[offset + 1] = (byte) ((value >>> 8) & 0xFF);
dst[offset + 2] = (byte) ((value >>> 16) & 0xFF);
}
/**
* Sets a 32-bit integer in the given byte array at the given offset.
*/
public static void setInt32(byte[] dst, int offset, int value) {
dst[offset + 0] = (byte) (value & 0xFF);
dst[offset + 1] = (byte) ((value >>> 8) & 0xFF);
dst[offset + 2] = (byte) ((value >>> 16) & 0xFF);
dst[offset + 3] = (byte) ((value >>> 24) & 0xFF);
}
/**
* Sets a 48-bit integer in the given byte array at the given offset.
*/
public static void setInt48(byte[] dst, int offset, long value) {
dst[offset + 0] = (byte) (value & 0xFF);
dst[offset + 1] = (byte) ((value >>> 8) & 0xFF);
dst[offset + 2] = (byte) ((value >>> 16) & 0xFF);
dst[offset + 3] = (byte) ((value >>> 24) & 0xFF);
dst[offset + 4] = (byte) ((value >>> 32) & 0xFF);
dst[offset + 5] = (byte) ((value >>> 40) & 0xFF);
}
/**
* Sets a 64-bit integer in the given byte array at the given offset.
*/
public static void setInt64(byte[] dst, int offset, long value) {
dst[offset + 0] = (byte) (value & 0xFF);
dst[offset + 1] = (byte) ((value >>> 8) & 0xFF);
dst[offset + 2] = (byte) ((value >>> 16) & 0xFF);
dst[offset + 3] = (byte) ((value >>> 24) & 0xFF);
dst[offset + 4] = (byte) ((value >>> 32) & 0xFF);
dst[offset + 5] = (byte) ((value >>> 40) & 0xFF);
dst[offset + 6] = (byte) ((value >>> 48) & 0xFF);
dst[offset + 7] = (byte) ((value >>> 56) & 0xFF);
}
}