Add documentation and remove unused methods

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

@@ -41,16 +41,20 @@ public class ByteUtil {
     }
 
     /**
-     * Omitting sign indication byte
+     * Omitting sign indication byte.
+     * <br/><br/>
+     * Instead of {@link org.spongycastle.util.BigIntegers#asUnsignedByteArray(BigInteger)} 
+     * <br/>we use this custom method to avoid an empty array in case of BigInteger.ZERO
      *
-     * @param b - any big integer number
+     * @param value - any big integer number. A <code>null</code>-value will return <code>null</code>
-     * @return a byte array representation of this number without a sign byte
+     * @return A byte array without a leading zero byte if present in the signed encoding. 
+     * 		BigInteger.ZERO will return an array with length 1 and byte-value 0.
      */
-    public static byte[] bigIntegerToBytes(BigInteger b) {
+    public static byte[] bigIntegerToBytes(BigInteger value) {
-        if (b == null)
+        if (value == null)
             return null;
         
-        byte[] data = b.toByteArray();
+        byte[] data = value.toByteArray();
 
         if (data.length != 1 && data[0] == 0) {
             byte[] tmp = new byte[data.length - 1];
@@ -65,8 +69,8 @@ public class ByteUtil {
      * 	amount will never be larger than smallest input
      * 
      * @param a - first input
-     * @param b second input
+     * @param b - second input
-     * @return number of bytes that match
+     * @return Number of bytes that match
      */
     public static int matchingNibbleLength(byte[] a, byte[] b) {
         int i = 0;
@@ -100,8 +104,7 @@ public class ByteUtil {
      * @see {@link Hex#toHexString}
      */
     public static String toHexString(byte[] data) {
-        if (data == null) return "";
+        return data == null ? "" : Hex.toHexString(data);
-        else return Hex.toHexString(data);
     }
     
     /**
@@ -177,22 +180,6 @@ public class ByteUtil {
         return bytes;
     }
     
-    /**
-     * Convert an array of byte arrays to a single string
-     * <br/>
-     * Example: "eth" or "eth shh bzz"
-     * 
-     * @return byte arrays as String
-     */
-    public static String toString(byte[][] arrays) {
-    	StringBuilder sb = new StringBuilder();
-		for (byte[] array : arrays) {
-			sb.append(new String(array)).append(" ");
-		}
-		if(sb.length() > 0) sb.deleteCharAt(sb.length()-1);
-		return sb.toString();
-    }
-
     /**
      * @param arg - not more that 32 bits
      * @return - bytes of the value pad with complete to 32 zeroes
@@ -279,26 +266,16 @@ public class ByteUtil {
         return (i >= startIndex || bytes[startIndex] != 0);
     }
 
-    public static byte[] padAddressWithZeroes(byte[] address){
-        if (address.length < 20) {
-            byte[] newAddr = new byte[20];
-            System.arraycopy(address, 0, newAddr, newAddr.length - address.length, address.length);
-            return newAddr;
-        }
-        return address;
-    }
-
     /**
      * Utility function to copy a byte array into a new byte array with given size.
      * If the src length is smaller than the given size, the result will be left-padded 
      * with zeros.
      * 
-     * @param src
+     * @param value - a BigInteger with a maximum value of 2^256-1
-     * @param size
      * @return Byte array of given size with a copy of the </code>src</code>
      */
-    public static byte[] copyToArray(BigInteger result) {
+    public static byte[] copyToArray(BigInteger value) {
-		byte[] src = ByteUtil.bigIntegerToBytes(result);
+		byte[] src = ByteUtil.bigIntegerToBytes(value);
     	byte[] dest = ByteBuffer.allocate(32).array();
     	System.arraycopy(src, 0, dest, dest.length - src.length, src.length);
     	return dest;

ethereumj-core/src/test/java/org/ethereum/util/ByteUtilTest.java

@@ -5,6 +5,8 @@ import static org.junit.Assert.*;
 import java.math.BigInteger;
 import java.nio.ByteBuffer;
 
+import javassist.bytecode.ByteArray;
+
 import org.junit.Test;
 import org.spongycastle.util.BigIntegers;
 import org.spongycastle.util.encoders.Hex;
@@ -18,33 +20,28 @@ public class ByteUtilTest {
 		assertArrayEquals("test".getBytes(), ByteUtil.appendByte(bytes, b));
 	}
 
-//	@Test
-//	public void testBigIntegerToBytes() {
-//		fail("Not yet implemented");
-//	}
-	
 	@Test
-	public void testToStringDoubleByteArray_1() {
+	public void testBigIntegerToBytes() {
-		String expected = "eth";
+		byte[] expecteds = new byte[]{0x0A};
-		byte[][] input = new byte[][]{"eth".getBytes()};
+		BigInteger b = BigInteger.valueOf(16772216);
-		String result = ByteUtil.toString(input);
+		byte[] actuals = ByteUtil.bigIntegerToBytes(b);
-		assertEquals(expected, result);
+		assertArrayEquals(expecteds, actuals);
 	}
 
 	@Test
-	public void testToStringDoubleByteArray_2() {
+	public void testBigIntegerToBytesNegative() {
-		String expected = "eth shh";
+		byte[] expecteds = new byte[]{0x01};
-		byte[][] input = new byte[][]{"eth".getBytes(), "shh".getBytes()};
+		BigInteger b = BigInteger.valueOf(-16772216);
-		String result = ByteUtil.toString(input);
+		byte[] actuals = ByteUtil.bigIntegerToBytes(b);
-		assertEquals(expected, result);
+		assertArrayEquals(expecteds, actuals);
 	}
 	
 	@Test 
-	public void testToStringDoubleByteArray_3() {
+	public void testBigIntegerToBytesZero() {
-		String expected = "";
+		byte[] expecteds = new byte[]{0x00};
-		byte[][] input = new byte[0][];
+		BigInteger b = BigInteger.ZERO;
-		String result = ByteUtil.toString(input);
+		byte[] actuals = ByteUtil.bigIntegerToBytes(b);
-		assertEquals(expected, result);
+		assertArrayEquals(expecteds, actuals);
 	}
 	
 	@Test
@@ -63,6 +60,22 @@ public class ByteUtilTest {
 	public void testByteArrayToInt() {
 		assertEquals(0, ByteUtil.byteArrayToInt(null));
 		assertEquals(0, ByteUtil.byteArrayToInt(new byte[0]));
+	
+//		byte[] x = new byte[] { 5,1,7,0,8 };
+//		long start = System.currentTimeMillis();
+//		for (int i = 0; i < 100000000; i++) {
+//			 ByteArray.read32bit(x, 0);
+//		}
+//		long end = System.currentTimeMillis();
+//		System.out.println(end - start + "ms");
+//
+//		long start1 = System.currentTimeMillis();
+//		for (int i = 0; i < 100000000; i++) {
+//			new BigInteger(1, x).intValue();
+//		}
+//		long end1 = System.currentTimeMillis();
+//		System.out.println(end1 - start1 + "ms");
+
 	}
 
 	@Test