Create ByteUtilTest and move testIncrementPerformance

This commit is contained in:
nicksavers 2014-06-26 19:52:36 +02:00
parent 279e380727
commit 33f887b76d
3 changed files with 124 additions and 90 deletions

View File

@ -47,19 +47,6 @@ public class ByteUtil {
else return Hex.toHexString(data);
}
// The packet size should be 4 byte long
public static byte[] calcPacketSize(byte[] packet){
byte[] size = new byte[4];
size[3] = (byte)(packet.length >> 0 & 0xFF);
size[2] = (byte)(packet.length >> 8 & 0xFF);
size[1] = (byte)(packet.length >> 16 & 0xFF);
size[0] = (byte)(packet.length >> 24 & 0xFF);
return size;
}
/**
* Calculate packet length
* @param msg
@ -118,19 +105,15 @@ public class ByteUtil {
byte[] data;
// check if the string is numeric
if (arg.toString().trim().matches("-?\\d+(\\.\\d+)?")) {
if (arg.toString().trim().matches("-?\\d+(\\.\\d+)?"))
data = new BigInteger(arg.toString().trim()).toByteArray();
// check if it's hex number
} else if (arg.toString().trim().matches("0[xX][0-9a-fA-F]+")){
// check if it's hex number
else if (arg.toString().trim().matches("0[xX][0-9a-fA-F]+"))
data = new BigInteger(arg.toString().trim().substring(2), 16).toByteArray();
} else {
else
data = arg.toString().trim().getBytes();
}
if (data.length > 32)
throw new RuntimeException("values can't be more than 32 byte");
@ -160,36 +143,29 @@ public class ByteUtil {
return baos.toByteArray();
}
public static byte[] stripLeadingZeroes(byte[] data) {
if (data == null)
return null;
int firstNonZero = 0;
int i = 0;
for (i = 0; i < data.length; ++i) {
if (data[i] != 0) {
firstNonZero = i;
break;
}
}
if (i == data.length)
return new byte[1];
if (firstNonZero == 0)
return data;
byte[] result = new byte[data.length - firstNonZero];
System.arraycopy(data, firstNonZero, result, 0, data.length - firstNonZero);
public static byte[] stripLeadingZeroes(byte[] data){
if (data == null) return null;
int firstNonZero = 0;
int i = 0;
for (i = 0; i < data.length; ++i)
if (data[i] != 0){
firstNonZero = i;
break;
}
if (i == data.length) return new byte[1];
if (firstNonZero == 0) return data;
byte[] result = new byte[data.length - firstNonZero];
System.arraycopy(data, firstNonZero, result, 0, data.length - firstNonZero);
return result;
}
return result;
}
/**
* increment byte array as a number until max is reached

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@ -3,13 +3,7 @@ package org.ethereum.core;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertTrue;
import java.math.BigInteger;
import java.nio.ByteBuffer;
import org.ethereum.util.ByteUtil;
import org.ethereum.util.FastByteComparisons;
import org.junit.Test;
import org.spongycastle.util.BigIntegers;
import org.spongycastle.util.encoders.Hex;
public class MinerTest {
@ -68,40 +62,4 @@ public class MinerTest {
newBlock.setStateRoot(Hex.decode("50188ab86bdf164ac90eb2835a04a8930aae5393c3a2ef1166fb95028f9456b8"));
return newBlock;
}
/**
* This test shows the difference between iterating over,
* and comparing byte[] vs BigInteger value.
*
* Results indicate that the former has ~15x better performance.
* Therefore this is used in the Miner.mine() method.
*/
@Test
public void testIncrementPerformance() {
boolean testEnabled = false;
if(testEnabled) {
byte[] counter1 = new byte[4];
byte[] max = ByteBuffer.allocate(4).putInt(Integer.MAX_VALUE).array();
long start1 = System.currentTimeMillis();
while(ByteUtil.increment(counter1)) {
if(FastByteComparisons.compareTo(counter1, 0, 4, max, 0, 4) == 0) {
break;
}
}
System.out.println(System.currentTimeMillis() - start1 + "ms to reach: " + Hex.toHexString(counter1));
BigInteger counter2 = BigInteger.ZERO;
long start2 = System.currentTimeMillis();
while(true) {
if(counter2.compareTo(BigInteger.valueOf(Integer.MAX_VALUE)) == 0) {
break;
}
counter2 = counter2.add(BigInteger.ONE);
}
System.out.println(System.currentTimeMillis() - start2 + "ms to reach: " + Hex.toHexString(BigIntegers.asUnsignedByteArray(4, counter2)));
}
}
}

View File

@ -0,0 +1,100 @@
package org.ethereum.util;
import static org.junit.Assert.*;
import java.math.BigInteger;
import java.nio.ByteBuffer;
import org.junit.Test;
import org.spongycastle.util.BigIntegers;
import org.spongycastle.util.encoders.Hex;
public class ByteUtilTest {
@Test
public void testAppendByte() {
byte[] bytes = "tes".getBytes();
byte b = 0x74;
assertArrayEquals("test".getBytes(), ByteUtil.appendByte(bytes, b));
}
// @Test
// public void testBigIntegerToBytes() {
// fail("Not yet implemented");
// }
@Test
public void testToHexString() {
assertEquals("null", ByteUtil.toHexString(null));
}
@Test
public void testCalcPacketLength() {
byte[] test = new byte[] { 0x0f, 0x10, 0x43 };
byte[] expected = new byte[] { 0x00, 0x00, 0x00, 0x03 };
assertArrayEquals(expected, ByteUtil.calcPacketLength(test));
}
@Test
public void testByteArrayToInt() {
assertEquals(0, ByteUtil.byteArrayToInt(null));
assertEquals(0, ByteUtil.byteArrayToInt(new byte[0]));
}
@Test
public void testNumBytes() {
String test1 = "0";
String test2 = "1";
String test3 = "1000000000"; //3B9ACA00
int expected1 = 1;
int expected2 = 1;
int expected3 = 4;
assertEquals(expected1, ByteUtil.numBytes(test1));
assertEquals(expected2, ByteUtil.numBytes(test2));
assertEquals(expected3, ByteUtil.numBytes(test3));
}
@Test
public void testStripLeadingZeroes() {
byte[] test1 = new byte[] { 0x00, 0x01 };
byte[] test2 = new byte[] { 0x00, 0x00, 0x01 };
byte[] expected = new byte[] { 0x01 };
assertArrayEquals(expected, ByteUtil.stripLeadingZeroes(test1));
assertArrayEquals(expected, ByteUtil.stripLeadingZeroes(test2));
}
/**
* This test shows the difference between iterating over,
* and comparing byte[] vs BigInteger value.
*
* Results indicate that the former has ~15x better performance.
* Therefore this is used in the Miner.mine() method.
*/
@Test
public void testIncrementPerformance() {
boolean testEnabled = false;
if(testEnabled) {
byte[] counter1 = new byte[4];
byte[] max = ByteBuffer.allocate(4).putInt(Integer.MAX_VALUE).array();
long start1 = System.currentTimeMillis();
while(ByteUtil.increment(counter1)) {
if(FastByteComparisons.compareTo(counter1, 0, 4, max, 0, 4) == 0) {
break;
}
}
System.out.println(System.currentTimeMillis() - start1 + "ms to reach: " + Hex.toHexString(counter1));
BigInteger counter2 = BigInteger.ZERO;
long start2 = System.currentTimeMillis();
while(true) {
if(counter2.compareTo(BigInteger.valueOf(Integer.MAX_VALUE)) == 0) {
break;
}
counter2 = counter2.add(BigInteger.ONE);
}
System.out.println(System.currentTimeMillis() - start2 + "ms to reach: " + Hex.toHexString(BigIntegers.asUnsignedByteArray(4, counter2)));
}
}
}