Impl variable length binary struct. Data will now be shifted to the correct possitions

This commit is contained in:
Ziver Koc 2016-05-11 17:11:18 +02:00
parent bae988e8dd
commit 3f21caa35b
7 changed files with 77 additions and 45 deletions

View file

@ -45,21 +45,7 @@ public class ByteUtil {
};
/**
* 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 from index and with the given length length
* 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
@ -83,7 +69,21 @@ public class ByteUtil {
}
/**
* Creates a new sub byte array with only the given length of bits from the data array.
* 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
@ -127,6 +127,32 @@ public class ByteUtil {
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
*

View file

@ -361,24 +361,10 @@ public class Converter {
int i = 0;
switch (b.length){
default:
case 4:
i |= 0xFF000000 & (b[0] << 24);
i |= 0x00FF0000 & (b[1] << 16);
i |= 0x0000FF00 & (b[2] << 8);
i |= 0x000000FF & b[3];
break;
case 3:
i |= 0x00FF0000 & (b[0] << 16);
i |= 0x0000FF00 & (b[1] << 8);
i |= 0x000000FF & b[2];
break;
case 2:
i |= 0x0000FF00 & (b[0] << 8);
i |= 0x000000FF & b[1];
break;
case 1:
i |= 0x000000FF & b[0];
break;
case 4: i |= 0xFF000000 & (b[3] << 24);
case 3: i |= 0x00FF0000 & (b[2] << 16);
case 2: i |= 0x0000FF00 & (b[1] << 8);
case 1: i |= 0x000000FF & b[0];
case 0: break;
}
return i;

View file

@ -95,7 +95,7 @@ public class BinaryFieldData {
else if (field.getType() == Integer.class || field.getType() == int.class)
field.set(obj, Converter.toInt(data));
else if (field.getType() == String.class)
field.set(obj, new String(data, StandardCharsets.ISO_8859_1));
field.set(obj, new String(ByteUtil.getReverseByteOrder(data), StandardCharsets.ISO_8859_1));
else
throw new UnsupportedOperationException("Unsupported BinaryStruct field class: "+ field.getClass());
} catch (IllegalAccessException e){

View file

@ -77,20 +77,23 @@ public class BinaryStructInputStream {
}
else {
byte[] valueData = new byte[(int) Math.ceil(field.getBitLength(struct) / 8.0)];
int fieldReadLength = 0;
int fieldReadLength = 0; // How much we have read so far
int shiftBy = (dataBitIndex+1 + field.getBitLength(struct)) % 8;
// Parse value
for (int valueDataIndex = 0; valueDataIndex < valueData.length; ++valueDataIndex) {
for (int valueDataIndex=valueData.length-1; valueDataIndex >= 0 ; --valueDataIndex) {
if (dataBitIndex < 0) { // Read new data?
data = (byte) in.read();
dataBitIndex = 7;
}
int bitLength = Math.min(dataBitIndex + 1, field.getBitLength(struct) - fieldReadLength);
valueData[valueDataIndex] = ByteUtil.getShiftedBits(data, dataBitIndex, bitLength);
fieldReadLength += bitLength;
dataBitIndex -= bitLength;
int subBitLength = Math.min(dataBitIndex + 1, field.getBitLength(struct) - fieldReadLength);
valueData[valueDataIndex] = ByteUtil.getBits(data, dataBitIndex, subBitLength);
fieldReadLength += subBitLength;
dataBitIndex -= subBitLength;
}
// Set value
ByteUtil.shiftLeft(valueData, shiftBy); // shift data so that LSB is at the beginning
field.setByteValue(struct, valueData);
totalReadLength += fieldReadLength;
}

View file

@ -99,4 +99,21 @@ public class ByteUtilTest {
"024 00 00 00 00 00 00 00 00 '........'",
ByteUtil.toFormattedString(data3));
}
@Test
public void shiftLeft(){
assertArrayEquals( new byte[]{},
ByteUtil.shiftLeft(new byte[]{}, 4));
assertArrayEquals( new byte[]{0b0000_0001},
ByteUtil.shiftLeft(new byte[]{0b0000_0001}, 0));
assertArrayEquals( new byte[]{0b0000_0001},
ByteUtil.shiftLeft(new byte[]{0b0001_0000}, 4));
assertArrayEquals( new byte[]{0b0001_0001, 0b0000_0000},
ByteUtil.shiftLeft(new byte[]{0b0001_0000, 0b0000_0001}, 4));
assertArrayEquals( new byte[]{0b0100_1001, 0b0000_0001},
ByteUtil.shiftLeft(new byte[]{0b0111_1111, 0b0101_0010}, 6));
assertArrayEquals( new byte[]{0b0000_0001,0b0000_0001,0b0000_0001,0b0000_0001},
ByteUtil.shiftLeft(new byte[]{0b0001_0000,0b0001_0000,0b0001_0000,0b0001_0000}, 4));
}
}

View file

@ -84,11 +84,11 @@ public class ConverterTest {
public void byteArrayToInt(){
assertEquals(0, Converter.toInt(new byte[]{}));
assertEquals(1, Converter.toInt(new byte[]{0b0000_0001}));
assertEquals(1, Converter.toInt(new byte[]{0x00,0x01}));
assertEquals(1, Converter.toInt(new byte[]{0x01,0x00}));
assertEquals(256, Converter.toInt(new byte[]{0x00,0x01,0x00}));
assertEquals(-1, Converter.toInt(new byte[]{(byte)0xFF,(byte)0xFF,(byte)0xFF,(byte)0xFF}));
assertEquals(Integer.MAX_VALUE, Converter.toInt(new byte[]{(byte)0x7F,(byte)0xFF,(byte)0xFF,(byte)0xFF}));
assertEquals(Integer.MAX_VALUE, Converter.toInt(new byte[]{(byte)0x7F,(byte)0xFF,(byte)0xFF,(byte)0xFF,(byte)0xFF,(byte)0xFF}));
assertEquals(Integer.MAX_VALUE, Converter.toInt(new byte[]{(byte)0xFF,(byte)0xFF,(byte)0xFF,(byte)0x7F}));
assertEquals(Integer.MAX_VALUE, Converter.toInt(new byte[]{(byte)0xFF,(byte)0xFF,(byte)0xFF,(byte)0x7F, (byte)0xFF,(byte)0xFF}));
}
@Test

View file

@ -112,7 +112,7 @@ public class BinaryStructInputStreamTest {
}
// TODO: add full non lined length support
// @Test
@Test
public void nonLinedLength2(){
BinaryTestStruct struct = new BinaryTestStruct() {
@BinaryField(index=1, length=12)