Don't create byte[] by default and have min size of 32 bytes

core/src/main/java/org/infinispan/protostream/impl/RawByteArrayOutputStreamImpl.java

@@ -1,16 +1,21 @@
 package org.infinispan.protostream.impl;
 
 import java.io.OutputStream;
+import java.nio.ByteBuffer;
 
 import net.jcip.annotations.NotThreadSafe;
 
 @NotThreadSafe
 public class RawByteArrayOutputStreamImpl extends OutputStream implements org.infinispan.protostream.RawByteArrayOutputStream {
 
+   static final int MIN_SIZE = 32;
+
    static final int DEFAULT_DOUBLING_SIZE = 4 * 1024 * 1024; // 4MB
 
+   byte[] buf;
+   int pos = 0;
+
    public RawByteArrayOutputStreamImpl() {
-      this(32);
    }
 
    public RawByteArrayOutputStreamImpl(int capacity) {
@@ -19,9 +24,6 @@ public RawByteArrayOutputStreamImpl(int capacity) {
       this.buf = new byte[capacity];
    }
 
-   byte[] buf;
-   int pos = 0;
-
    @Override
    public void write(int b) {
       int newpos = pos + 1;
@@ -52,7 +54,7 @@ public void write(byte[] b, int off, int len) {
    @Override
    public void ensureCapacity(int capacity) {
       if (buf == null) {
-         buf = new byte[capacity];
+         buf = new byte[Math.max(MIN_SIZE, capacity)];
       } else if (capacity > buf.length) {
          byte[] newbuf = new byte[getNewBufferSize(buf.length, capacity)];
          System.arraycopy(buf, 0, newbuf, 0, pos);
@@ -81,4 +83,11 @@ public void setPosition(int position) {
    public byte[] getRawBuffer() {
       return buf;
    }
+
+   @Override
+   public ByteBuffer getByteBuffer() {
+      return buf == null ?
+            ByteBuffer.wrap(new byte[0]) :
+            ByteBuffer.wrap(buf, 0, getPosition());
+   }
 }