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Remove array length check from DataWord and use better test

This commit is contained in:
nicksavers 2014-06-04 07:57:31 +02:00
parent de0f67ae3b
commit 4868ecfc0e
4 changed files with 38 additions and 46 deletions
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68
ethereumj-core/src/main/java/org/ethereum/vm/DataWord.java
View File

@ -7,34 +7,31 @@ import java.math.BigInteger;
import java.nio.ByteBuffer;
/**
* www.ethereumJ.com
* User: Roman Mandeleil
* Created on: 01/06/2014 19:47
* DataWord is the 32-byte array representation of a 256-bit number
* Calculations can be done on this word with other DataWords
*/
public class DataWord {
static DataWord ZERO = new DataWord(new byte[32]); // don't push it in to the stack
byte[] data = new byte[32];
public DataWord(){
data = new byte[32];
}
public DataWord() {
data = new byte[32];
}
public DataWord(int num){
ByteBuffer bInt = ByteBuffer.allocate(4).putInt(num);
ByteBuffer data = ByteBuffer.allocate(32);
System.arraycopy(bInt.array(), 0, data.array(), 28, 4);
this.data = data.array();
}
public DataWord(int num) {
ByteBuffer bInt = ByteBuffer.allocate(4).putInt(num);
ByteBuffer data = ByteBuffer.allocate(32);
System.arraycopy(bInt.array(), 0, data.array(), 28, 4);
this.data = data.array();
}
public DataWord(byte[] data){
if (data == null || data.length > 32)
throw new RuntimeException("bad push data: " + data);
System.arraycopy(data, 0, this.data, 32 - data.length, data.length);
}
public DataWord(byte[] data) {
if (data == null || data.length > 32)
throw new RuntimeException("bad push data: " + data);
System.arraycopy(data, 0, this.data, 32 - data.length, data.length);
}
public byte[] getData() {
return data;
@ -95,8 +92,19 @@ public class DataWord {
}
}
// todo: add can be done in more efficient way
// todo without BigInteger quick hack
// By : Holger
// From : http://stackoverflow.com/a/24023466/459349
public void add(DataWord word) {
byte[] result = new byte[32];
for (int i = 31, overflow = 0; i >= 0; i--) {
int v = (this.data[i] & 0xff) + (word.data[i] & 0xff) + overflow;
result[i] = (byte) v;
overflow = v >>> 8;
}
this.data = result;
}
// old add-method with BigInteger quick hack
public void add2(DataWord word){
BigInteger result = value().add( word.value() );
@ -107,24 +115,10 @@ public class DataWord {
this.data = data.array();
}
// By : Holger
// From : http://stackoverflow.com/a/24023466/459349
public void add(DataWord word) {
if (this.data.length != 32 || word.data.length != 32)
throw new IllegalArgumentException();
byte[] result = new byte[32];
for (int i = 31, overflow = 0; i >= 0; i--) {
int v = (this.data[i] & 0xff) + (word.data[i] & 0xff) + overflow;
result[i] = (byte) v;
overflow = v >>> 8;
}
this.data = result;
}
// todo: mull can be done in more efficient way
// todo: mul can be done in more efficient way
// todo: with shift left shift right trick
// todo without BigInteger quick hack
public void mull(DataWord word){
public void mul(DataWord word){
BigInteger result = value().multiply( word.value() );
byte[] bytes = result.toByteArray();

2
ethereumj-core/src/main/java/org/ethereum/vm/VM.java
View File

@ -55,7 +55,7 @@ public class VM {
DataWord word1 = program.stackPop();
DataWord word2 = program.stackPop();
word1.mull(word2);
word1.mul(word2);
program.stackPush(word1);
program.step();
}

13
ethereumj-core/src/test/java/org/ethereum/vm/DataWordTest.java
View File

@ -2,9 +2,8 @@ package org.ethereum.vm;
import static org.junit.Assert.*;
import java.math.BigInteger;
import org.junit.Test;
import org.spongycastle.util.encoders.Hex;
public class DataWordTest {
@ -41,15 +40,15 @@ public class DataWordTest {
@Test
public void testAdd2() {
byte[] two = new byte[32];
two[31] = 0x01; // 0x00000000000000000000000000000000000000000000000000000000000001
two[31] = (byte) 0xff; // 0x000000000000000000000000000000000000000000000000000000000000ff
DataWord x = new DataWord(two);
x.add(new DataWord(two));
System.out.println(new BigInteger(1, x.data));
System.out.println(Hex.toHexString(x.data));
DataWord y = new DataWord(two);
y.add2(new DataWord(two));
System.out.println(new BigInteger(1, y.data));
System.out.println(Hex.toHexString(y.data));
}
@Test
@ -62,11 +61,11 @@ public class DataWordTest {
DataWord x = new DataWord(three);
x.add(new DataWord(three));
assertEquals(32, x.data.length);
System.out.println(new BigInteger(1, x.data));
System.out.println(Hex.toHexString(x.data));
// FAIL
// DataWord y = new DataWord(three);
// y.add2(new DataWord(three));
// System.out.println(new BigInteger(1, y.data));
// System.out.println(Hex.toHexString(y.data));
}
}

1
ethereumj-core/src/test/java/org/ethereum/vm/VMTest.java
View File

@ -1,6 +1,5 @@
package org.ethereum.vm;
import org.ethereum.crypto.HashUtil;
import org.junit.Test;
import org.spongycastle.util.encoders.Hex;