/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*
*/
/**
* ByteUtilities.java - Byte manipulation functions.
*
* @author Apache MINA Project
* @since MINA 2.0.0-M3
*/
public class Util{
/**
* Invert the endianness of words (4 bytes) in the given byte array
* starting at the given offset and repeating length/4 times.
* eg: b0b1b2b3 -> b3b2b1b0
*
* @param b the byte array
* @param offset the offset at which to change word start
* @param length the number of bytes on which to operate
* (should be a multiple of 4)
*/
public final static void changeWordEndianess(byte[] b, int offset,
int length) {
byte tmp;
for (int i = offset; i < offset + length; i += 4) {
tmp = b[i];
b[i] = b[i + 3];
b[i + 3] = tmp;
tmp = b[i + 1];
b[i + 1] = b[i + 2];
b[i + 2] = tmp;
}
}
/**
* Invert two bytes in the given byte array starting at the given
* offset and repeating the inversion length/2 times.
* eg: b0b1 -> b1b0
*
* @param b the byte array
* @param offset the offset at which to change word start
* @param length the number of bytes on which to operate
* (should be a multiple of 2)
*/
public final static void changeByteEndianess(byte[] b, int offset,
int length) {
byte tmp;
for (int i = offset; i < offset + length; i += 2) {
tmp = b[i];
b[i] = b[i + 1];
b[i + 1] = tmp;
}
}
}