performance upgrades: avoid copying

Author: siilike

.gitignore

@@ -5,3 +5,6 @@
 /.idea
 /*.iml
 *.jfr
+/.gradle
+/bin
+/build

src/main/java/com/arangodb/velocypack/VPackBuilder.java

@@ -652,9 +652,11 @@ private <T> VPackBuilder addInternal(final String attribute, final long tag, fin
 					final VPackSlice translate = VPackSlice.attributeTranslator.translate(attribute);
 					if (translate != null) {
 						final byte[] trValue = translate.getRawVPack();
-						ensureCapacity(size + trValue.length);
-						for (int i = 0; i < trValue.length; i++) {
-							addUnchecked(trValue[i]);
+						int trValueLength = translate.getByteSize();
+						int trValueStart = translate.getStart();
+						ensureCapacity(size + trValueLength);
+						for (int i = 0; i < trValueLength; i++) {
+							addUnchecked(trValue[i+trValueStart]);
 						}
 						keyWritten = true;
 						if (value == null) {
@@ -837,9 +839,10 @@ private void appendBinary(final byte[] value) {
 
 	private void appendVPack(final VPackSlice value) {
 		final byte[] vpack = value.getRawVPack();
-		ensureCapacity(size + vpack.length);
-		System.arraycopy(vpack, 0, buffer, size, vpack.length);
-		size += vpack.length;
+		int length = value.getByteSize();
+		ensureCapacity(size + length);
+		System.arraycopy(vpack, value.getStart(), buffer, size, length);
+		size += length;
 	}
 
 	private void addArray(final boolean unindexed) {

src/main/java/com/arangodb/velocypack/VPackSlice.java

@@ -902,14 +902,18 @@ public Iterator<Entry<String, VPackSlice>> objectIterator() {
 		}
 	}
 
-	protected byte[] getRawVPack() {
+	protected byte[] getVPack() {
 		if(start == 0 && vpack.length == getByteSize()) {
 			return vpack;
 		}
 
 		return Arrays.copyOfRange(vpack, start, start + getByteSize());
 	}
 
+	protected byte[] getRawVPack() {
+		return vpack;
+	}
+
 	@Override
 	public String toString() {
 		try {
@@ -924,7 +928,12 @@ public int hashCode() {
 		final int prime = 31;
 		int result = 1;
 		result = prime * result + start;
-		result = prime * result + Arrays.hashCode(getRawVPack());
+
+		int arrayHash = 1;
+		for (int i = start, max = getByteSize(); i < max; i++)
+			arrayHash = 31 * arrayHash + vpack[i];
+
+		result = prime * result + arrayHash;
 		return result;
 	}
 
@@ -940,12 +949,20 @@ public boolean equals(final Object obj) {
 			return false;
 		}
 		final VPackSlice other = (VPackSlice) obj;
-		if (start != other.start) {
+
+		int byteSize = getByteSize();
+		int otherByteSize = other.getByteSize();
+
+		if(byteSize != otherByteSize) {
 			return false;
 		}
-		if (!Arrays.equals(getRawVPack(), other.getRawVPack())) {
-			return false;
+
+		for(int i = 0; i < byteSize; i++) {
+			if(vpack[i+start] != other.vpack[i+other.start]) {
+				return false;
+			}
 		}
+
 		return true;
 	}
 

src/test/java/com/arangodb/velocypack/VPackUtil.java

@@ -30,9 +30,11 @@ public class VPackUtil {
 
 	public static String toHex(final VPackSlice vpack) {
 		final byte[] bytes = vpack.getRawVPack();
-		final char[] hexChars = new char[bytes.length * 2];
+		final int bytesLength = vpack.getByteSize();
+		final int bytesStart = vpack.getStart();
+		final char[] hexChars = new char[bytesLength * 2];
 		for (int j = 0; j < bytes.length; j++) {
-			final int v = bytes[j] & 0xFF;
+			final int v = bytes[j+bytesStart] & 0xFF;
 			hexChars[j * 2] = hexArray[v >>> 4];
 			hexChars[j * 2 + 1] = hexArray[v & 0x0F];
 		}