scouter.javassist.bytecode.ByteArray Maven / Gradle / Ivy
/*
* Javassist, a Java-bytecode translator toolkit.
* Copyright (C) 1999- Shigeru Chiba. All Rights Reserved.
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. Alternatively, the contents of this file may be used under
* the terms of the GNU Lesser General Public License Version 2.1 or later,
* or the Apache License Version 2.0.
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*/
package scouter.javassist.bytecode;
/**
* A collection of static methods for reading and writing a byte array.
*/
public class ByteArray {
/**
* Reads an unsigned 16bit integer at the index.
*/
public static int readU16bit(byte[] code, int index) {
return ((code[index] & 0xff) << 8) | (code[index + 1] & 0xff);
}
/**
* Reads a signed 16bit integer at the index.
*/
public static int readS16bit(byte[] code, int index) {
return (code[index] << 8) | (code[index + 1] & 0xff);
}
/**
* Writes a 16bit integer at the index.
*/
public static void write16bit(int value, byte[] code, int index) {
code[index] = (byte)(value >>> 8);
code[index + 1] = (byte)value;
}
/**
* Reads a 32bit integer at the index.
*/
public static int read32bit(byte[] code, int index) {
return (code[index] << 24) | ((code[index + 1] & 0xff) << 16)
| ((code[index + 2] & 0xff) << 8) | (code[index + 3] & 0xff);
}
/**
* Writes a 32bit integer at the index.
*/
public static void write32bit(int value, byte[] code, int index) {
code[index] = (byte)(value >>> 24);
code[index + 1] = (byte)(value >>> 16);
code[index + 2] = (byte)(value >>> 8);
code[index + 3] = (byte)value;
}
/**
* Copies a 32bit integer.
*
* @param src the source byte array.
* @param isrc the index into the source byte array.
* @param dest the destination byte array.
* @param idest the index into the destination byte array.
*/
static void copy32bit(byte[] src, int isrc, byte[] dest, int idest) {
dest[idest] = src[isrc];
dest[idest + 1] = src[isrc + 1];
dest[idest + 2] = src[isrc + 2];
dest[idest + 3] = src[isrc + 3];
}
}