Re-use static variable for Word with EMPTY_BYTE_ARRAY

ethereumj-core/src/main/java/org/ethereum/vm/DataWord.java

@@ -19,11 +19,11 @@ import java.nio.ByteBuffer;
 public class DataWord implements Comparable<DataWord> {
 
     public static final DataWord ZERO 				= new DataWord(new byte[32]);      // don't push it in to the stack
+    public static final DataWord ZERO_EMPTY_ARRAY	= new DataWord(new byte[0]);      // don't push it in to the stack
 
-    byte[] data = new byte[32];
+    private byte[] data = new byte[32];
 
 	public DataWord() {
-		this.data = new byte[32];
 	}
 
 	public DataWord(int num) {

ethereumj-core/src/main/java/org/ethereum/vm/Program.java

@@ -3,6 +3,7 @@ package org.ethereum.vm;
 import org.ethereum.crypto.HashUtil;
 import org.ethereum.db.ContractDetails;
 import org.ethereum.db.Repository;
+import org.ethereum.util.ByteUtil;
 import org.ethereum.util.Utils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -25,7 +26,7 @@ public class Program {
     private int invokeHash;
     private ProgramListener listener;
 
-    Stack<DataWord> stack = new Stack<DataWord>();
+    Stack<DataWord> stack = new Stack<>();
     ByteBuffer memory = null;
     DataWord programAddress;
 
@@ -147,7 +148,7 @@ public class Program {
     }
 
     public void memorySave(DataWord addrB, DataWord value) {
-        memorySave(addrB.data, value.data);
+        memorySave(addrB.getData(), value.getData());
     }
 
     public void memorySave(byte[] addr, byte[] value) {
@@ -160,7 +161,7 @@ public class Program {
     public DataWord memoryLoad(DataWord addr) {
 
         int address = new BigInteger(1, addr.getData()).intValue();
-        allocateMemory(address, DataWord.ZERO.data);
+        allocateMemory(address, DataWord.ZERO.getData());
 
         byte[] data = new byte[32];
         System.arraycopy(memory.array(), address,  data , 0  ,32);
@@ -465,12 +466,12 @@ public class Program {
     }
 
     public DataWord getOwnerAddress() {
-        if (invokeData == null) return new DataWord( new byte[0]);
+        if (invokeData == null) return DataWord.ZERO_EMPTY_ARRAY;
         return this.programAddress.clone();
     }
 
     public DataWord getBalance(DataWord address) {
-        if (invokeData == null) return new DataWord( new byte[0]);
+        if (invokeData == null) return DataWord.ZERO_EMPTY_ARRAY;
 
         BigInteger balance = result.getRepository().getBalance(address.getLast20Bytes());
         DataWord balanceData = new DataWord(balance.toByteArray());
@@ -479,43 +480,43 @@ public class Program {
     }
 
     public DataWord getOriginAddress() {
-        if (invokeData == null) return new DataWord( new byte[0]);
+        if (invokeData == null) return DataWord.ZERO_EMPTY_ARRAY;
         return invokeData.getOriginAddress().clone();
     }
 
     public DataWord getCallerAddress() {
-        if (invokeData == null) return new DataWord( new byte[0]);
+        if (invokeData == null) return DataWord.ZERO_EMPTY_ARRAY;
         return invokeData.getCallerAddress().clone();
     }
 
     public DataWord getGasPrice() {
-        if (invokeData == null) return new DataWord( new byte[0]);
+        if (invokeData == null) return DataWord.ZERO_EMPTY_ARRAY;
         return invokeData.getMinGasPrice().clone();
     }
 
     public DataWord getGas() {
-        if (invokeData == null) return new DataWord( new byte[0]);
+        if (invokeData == null) return DataWord.ZERO_EMPTY_ARRAY;
         long afterSpend = invokeData.getGas().longValue() - result.getGasUsed();
         return new DataWord(afterSpend);
     }
 
     public DataWord getCallValue() {
-        if (invokeData == null) return new DataWord( new byte[0]);
+        if (invokeData == null) return DataWord.ZERO_EMPTY_ARRAY;
         return invokeData.getCallValue().clone();
     }
 
     public DataWord getDataSize() {
-        if (invokeData == null) return new DataWord( new byte[0]);
+        if (invokeData == null) return DataWord.ZERO_EMPTY_ARRAY;
         return invokeData.getDataSize().clone();
     }
 
     public DataWord getDataValue(DataWord index) {
-        if (invokeData == null) return new DataWord( new byte[0]);
+        if (invokeData == null) return DataWord.ZERO_EMPTY_ARRAY;
         return invokeData.getDataValue(index);
     }
 
     public byte[] getDataCopy(DataWord offset, DataWord length) {
-        if (invokeData == null) return new byte[0];
+        if (invokeData == null) return ByteUtil.EMPTY_BYTE_ARRAY;
         return invokeData.getDataCopy(offset, length);
     }
 

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

@@ -449,7 +449,7 @@ public class VM {
                     if (logger.isInfoEnabled())
                         hint = "data: " + Hex.toHexString(msgData);
 
-                    program.memorySave(memOffsetData.data, msgData);
+                    program.memorySave(memOffsetData.getData(), msgData);
                     program.step();
                 }	break;
                 case CODESIZE:{
@@ -759,7 +759,7 @@ public class VM {
             if (memoryUsage > 0)
                 program.spendGas(GasCost.MEMORY * memoryUsage, OpCode.code(op).name() + " (memory usage)");
 
-            program.fullTrace();
+//            program.fullTrace();
         } catch (RuntimeException e) {
             program.stop();
             if(e instanceof OutOfGasException)

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

@@ -44,11 +44,11 @@ public class DataWordTest {
 		
 		DataWord x = new DataWord(two);
 		x.add(new DataWord(two));
-		System.out.println(Hex.toHexString(x.data));
+		System.out.println(Hex.toHexString(x.getData()));
 		
 		DataWord y = new DataWord(two);
 		y.add2(new DataWord(two));
-		System.out.println(Hex.toHexString(y.data));
+		System.out.println(Hex.toHexString(y.getData()));
 	}
 	
 	@Test
@@ -60,13 +60,13 @@ public class DataWordTest {
 		
 		DataWord x = new DataWord(three);
 		x.add(new DataWord(three));
-		assertEquals(32, x.data.length);
+		assertEquals(32, x.getData().length);
-		System.out.println(Hex.toHexString(x.data));
+		System.out.println(Hex.toHexString(x.getData()));
 
 		// FAIL
 //		DataWord y = new DataWord(three);
 //		y.add2(new DataWord(three));
-//		System.out.println(Hex.toHexString(y.data));
+//		System.out.println(Hex.toHexString(y.getData()));
 	}
 	
 	@Test
@@ -85,7 +85,7 @@ public class DataWordTest {
 		DataWord x = new DataWord(one);// System.out.println(x.value());
 		DataWord y = new DataWord(two);// System.out.println(y.value());
 		y.mod(x);
-		assertEquals(32, y.data.length);
+		assertEquals(32, y.getData().length);
-		assertEquals(expected, Hex.toHexString(y.data));
+		assertEquals(expected, Hex.toHexString(y.getData()));
 	}
 }