hal/src/zutil/ByteUtil.java

205 lines
7.5 KiB
Java
Executable file

/*
* The MIT License (MIT)
*
* Copyright (c) 2015 Ziver Koc
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package zutil;
import zutil.converter.Converter;
/**
* Utility functions for byte primitive type
*
* Created by Ziver on 2016-01-30.
*/
public class ByteUtil {
/** Bitmask array used by utility functions **/
private static final int[][] BYTE_MASK = new int[][]{
{0b0000_0001},
{0b0000_0010, 0b0000_0011},
{0b0000_0100, 0b0000_0110, 0b0000_0111},
{0b0000_1000, 0b0000_1100, 0b0000_1110, 0b0000_1111},
{0b0001_0000, 0b0001_1000, 0b0001_1100, 0b0001_1110, 0b0001_1111},
{0b0010_0000, 0b0011_0000, 0b0011_1000, 0b0011_1100, 0b0011_1110, 0b0011_1111},
{0b0100_0000, 0b0110_0000, 0b0111_0000, 0b0111_1000, 0b0111_1100, 0b0111_1110, 0b0111_1111},
{0b1000_0000, 0b1100_0000, 0b1110_0000, 0b1111_0000, 0b1111_1000, 0b1111_1100, 0b1111_1110, 0b1111_1111}
};
/**
* Creates a new sub byte from MSB to the given length
*
* @param data is the byte data
* @param length is the length of bits to return, valid values 1-8
* @return a new byte containing a sub byte defined by the index and length
*/
public static byte getBits(byte data, int length){
return getBits(data, length-1, length);
}
/**
* Creates a new sub byte from index and with the given length length
*
* @param data is the byte data
* @param index is the bit index, valid values 0-7
* @param length is the length of bits to return, valid values 1-8
* @return a new byte containing a sub byte defined by the index and length
*/
public static byte getBits(byte data, int index, int length){
byte ret = (byte) (data & getBitMask(index, length));
return ret;
}
/**
* Creates a new sub byte from index and with a length and shifts the data to the left
*
* @param data is the byte data
* @param index is the bit index, valid values 0-7
* @param length is the length of bits to return, valid values 1-8
* @return a new byte containing a sub byte defined by the index and length
*/
public static byte getShiftedBits(byte data, int index, int length){
int ret = 0xFF & getBits(data, index, length);
ret = ret >>> index+1-length;
return (byte) ret;
}
/**
* Creates a new sub byte array with only the given length of bits from the LSB.
*
* @param data is the byte data array
* @param length is the length of bits to return
* @return a new byte array of te given length containing the given data.
*/
public static byte[] getBits(byte[] data, int length){
byte[] dest = new byte[(int) Math.ceil(length/8.0)];
System.arraycopy(data, 0, dest, 0, Math.min(data.length, dest.length));
if(length % 8 != 0)
dest[dest.length-1] = getBits(dest[dest.length-1], length % 8);
return dest;
}
/**
* Creates a new byte array with reversed byte ordering
* (LittleEndian -> BigEndian, BigEndian -> LittleEndian)
*
* @param data is the byte array that will be reversed.
* @return a new byte array that will have the same data but in reverse byte order
*/
public static byte[] getReverseByteOrder(byte[] data){
byte[] dest = new byte[data.length];
if (data.length > 0)
for (int i=0; i<data.length; ++i)
dest[dest.length-1-i] = data[i];
return dest;
}
/**
* Returns a byte bitmask
*
* @param index start index of the mask, valid values 0-7
* @param length length of mask from index, valid values 1-8 depending on index
*/
public static byte getBitMask(int index, int length) {
--length;
if(0 > index || index > 7)
throw new IllegalArgumentException("Invalid index argument, allowed values: 0-7");
if(length < 0 || index-length < 0)
throw new IllegalArgumentException("Invalid length argument: "+length+", allowed values: 1 to "+(index+1)+" for index "+index);
return (byte) BYTE_MASK[index][length];
}
/**
* Shifts a whole byte array to the left by the specified amount.
*
* @param data the array to be shifted
* @param shiftBy the amount to shift. Currently only supports maximum value of 8
* @return same data reference as the data input
*/
public static byte[] shiftLeft(byte[] data, int shiftBy) {
if(0 > shiftBy || shiftBy > 8)
throw new IllegalArgumentException("Invalid shiftBy argument, allowed values: 0-8");
if (shiftBy == 0)
return data;
byte rest = 0;
for (int i=0; i<data.length; ++i){
rest = (byte)(getBits(data[i], shiftBy-1, shiftBy) << 8 - shiftBy);
data[i] >>>= shiftBy;
if(i != 0)
data[i-1] |= rest;
}
return data;
}
/**
* Presents a binary array in HEX and ASCII
*
* @param data The source binary data to format
* @return A multiline String with human readable HEX and ASCII
*/
public static String toFormattedString(byte[] data){
StringBuffer output = new StringBuffer();
//000 XX XX XX XX XX XX XX XX '........'
int maxOffset = (""+data.length).length();
for(int offset=0; offset<data.length; offset+=8){
if(offset != 0)
output.append('\n');
// Offset
String offsetStr = ""+offset;
for(int i=offsetStr.length(); i<3 || i<maxOffset; ++i){
output.append('0');
}
output.append(offsetStr);
output.append(" ");
// HEX
for(int i=0; i<8; ++i){
if(offset+i < data.length)
output.append(Converter.toHexString(data[offset+i]));
else
output.append(" ");
output.append(' ');
}
output.append(' ');
// ACII
output.append('\'');
for(int i=0; i<8; ++i){
if(offset+i < data.length)
if( 32 <= data[offset+i] && data[offset+i] <= 126 )
output.append((char)data[offset+i]);
else
output.append('.');
else
output.append(' ');
}
output.append('\'');
}
return output.toString();
}
}