Make DataWord immutable

ethereumj-core/src/main/java/org/ethereum/config/CommonConfig.java

@@ -258,9 +258,9 @@ public Source<byte[], ProgramPrecompile> precompileSource() {
         return new SourceCodec<byte[], ProgramPrecompile, byte[], byte[]>(source,
                 new Serializer<byte[], byte[]>() {
                     public byte[] serialize(byte[] object) {
-                        DataWord ret = new DataWord(object);
-                        ret.add(new DataWord(1));
-                        return ret.getLast20Bytes();
+                        DataWord ret = DataWord.of(object);
+                        DataWord addResult = ret.add(DataWord.ONE);
+                        return addResult.getLast20Bytes();
                     }
                     public byte[] deserialize(byte[] stream) {
                         throw new RuntimeException("Shouldn't be called");

ethereumj-core/src/main/java/org/ethereum/config/blockchain/AbstractConfig.java

@@ -140,7 +140,7 @@ public DataWord getCallGas(OpCode op, DataWord requestedGas, DataWord availableG
         if (requestedGas.compareTo(availableGas) > 0) {
             throw Program.Exception.notEnoughOpGas(op, requestedGas, availableGas);
         }
-        return requestedGas.clone();
+        return requestedGas;
     }
 
     @Override

ethereumj-core/src/main/java/org/ethereum/core/TransactionExecutionSummary.java

@@ -141,8 +141,8 @@ public static TransactionTouchedStorage decodeTouchedStorage(RLPElement encoded)
         for (RLPElement entry : (RLPList) encoded) {
             RLPList asList = (RLPList) entry;
 
-            DataWord key = new DataWord(asList.get(0).getRLPData());
-            DataWord value = new DataWord(asList.get(1).getRLPData());
+            DataWord key = DataWord.of(asList.get(0).getRLPData());
+            DataWord value = DataWord.of(asList.get(1).getRLPData());
             byte[] changedBytes = asList.get(2).getRLPData();
             boolean changed = isNotEmpty(changedBytes) && RLP.decodeInt(changedBytes, 0) == 1;
 
@@ -184,8 +184,8 @@ private static byte[] encodeStorageDiff(Map<DataWord, DataWord> storageDiff) {
     private static Map<DataWord, DataWord> decodeStorageDiff(RLPList storageDiff) {
         Map<DataWord, DataWord> result = new HashMap<>();
         for (RLPElement entry : storageDiff) {
-            DataWord key = new DataWord(((RLPList) entry).get(0).getRLPData());
-            DataWord value = new DataWord(((RLPList) entry).get(1).getRLPData());
+            DataWord key = DataWord.of(((RLPList) entry).get(0).getRLPData());
+            DataWord value = DataWord.of(((RLPList) entry).get(1).getRLPData());
             result.put(key, value);
         }
         return result;
@@ -222,7 +222,7 @@ private static byte[] encodeDeletedAccounts(List<DataWord> deletedAccounts) {
     private static List<DataWord> decodeDeletedAccounts(RLPList deletedAccounts) {
         List<DataWord> result = new ArrayList<>();
         for (RLPElement deletedAccount : deletedAccounts) {
-            result.add(new DataWord(deletedAccount.getRLPData()));
+            result.add(DataWord.of(deletedAccount.getRLPData()));
         }
         return result;
     }

ethereumj-core/src/main/java/org/ethereum/core/TransactionExecutor.java

@@ -207,7 +207,7 @@ private void call() {
         if (!readyToExecute) return;
 
         byte[] targetAddress = tx.getReceiveAddress();
-        precompiledContract = PrecompiledContracts.getContractForAddress(new DataWord(targetAddress), blockchainConfig);
+        precompiledContract = PrecompiledContracts.getContractForAddress(DataWord.of(targetAddress), blockchainConfig);
 
         if (precompiledContract != null) {
             long requiredGas = precompiledContract.getGasForData(tx.getData());

ethereumj-core/src/main/java/org/ethereum/datasource/Serializers.java

@@ -69,7 +69,7 @@ public byte[] serialize(DataWord object) {
 
         @Override
         public DataWord deserialize(byte[] stream) {
-            return new DataWord(stream);
+            return DataWord.of(stream);
         }
     };
 
@@ -86,7 +86,7 @@ public byte[] serialize(DataWord object) {
         public DataWord deserialize(byte[] stream) {
             if (stream == null || stream.length == 0) return null;
             byte[] dataDecoded = RLP.decode2(stream).get(0).getRLPData();
-            return new DataWord(dataDecoded);
+            return DataWord.of(dataDecoded);
         }
     };
 

ethereumj-core/src/main/java/org/ethereum/listener/LogFilter.java

@@ -100,7 +100,7 @@ public boolean matchesExactly(LogInfo logInfo) {
                 boolean orMatches = false;
                 DataWord logTopic = logTopics.get(i);
                 for (byte[] orTopic : orTopics) {
-                    if (new DataWord(orTopic).equals(logTopic)) {
+                    if (DataWord.of(orTopic).equals(logTopic)) {
                         orMatches = true;
                         break;
                     }

ethereumj-core/src/main/java/org/ethereum/util/Utils.java

@@ -40,7 +40,7 @@
 import javax.swing.*;
 
 public class Utils {
-    private static final DataWord DIVISOR = new DataWord(64);
+    private static final DataWord DIVISOR = DataWord.of(64);
 
     private static SecureRandom random = new SecureRandom();
 
@@ -230,11 +230,8 @@ public static List<ByteArrayWrapper> dumpKeys(DbSource<byte[]> ds) {
     }
 
     public static DataWord allButOne64th(DataWord dw) {
-        DataWord ret = dw.clone();
-        DataWord d = dw.clone();
-        d.div(DIVISOR);
-        ret.sub(d);
-        return ret;
+        DataWord divResult = dw.div(DIVISOR);
+        return dw.sub(divResult);
     }
 
     /**

ethereumj-core/src/main/java/org/ethereum/util/blockchain/StandaloneBlockchain.java

@@ -701,12 +701,12 @@ public SolidityStorageImpl(byte[] contractAddr) {
 
         @Override
         public byte[] getStorageSlot(long slot) {
-            return getStorageSlot(new DataWord(slot).getData());
+            return getStorageSlot(DataWord.of(slot).getData());
         }
 
         @Override
         public byte[] getStorageSlot(byte[] slot) {
-            DataWord ret = getBlockchain().getRepository().getContractDetails(contractAddr).get(new DataWord(slot));
+            DataWord ret = getBlockchain().getRepository().getContractDetails(contractAddr).get(DataWord.of(slot));
             return ret.getData();
         }
     }