/*

  * Copyright 2007-2008 The Kuali Foundation

  *

  * Licensed under the Educational Community License, Version 2.0 (the "License");

  * you may not use this file except in compliance with the License.

  * You may obtain a copy of the License at

  *

  * http://www.opensource.org/licenses/ecl2.php

  *

  * Unless required by applicable law or agreed to in writing, software

  * distributed under the License is distributed on an "AS IS" BASIS,

  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

  * See the License for the specific language governing permissions and

  * limitations under the License.

  */

 package org.kuali.rice.kns.util.cache;

 import java.io.InputStream;

 import java.io.OutputStream;

 /**

  * ByteArrayOutputStream implementation that doesn't synchronize methods

  * and doesn't copy the data on toByteArray().

  */

 public class FastByteArrayOutputStream extends OutputStream {

     /**

      * Buffer and size

      */

     protected byte[] buf = null;

     protected int size = 0;

     /**

      * Constructs a stream with buffer capacity size 5K

      */

     public FastByteArrayOutputStream() {

         this(5 * 1024);

     }

     /**

      * Constructs a stream with the given initial size

      */

     public FastByteArrayOutputStream(int initSize) {

         this.size = 0;

         this.buf = new byte[initSize];

     }

     /**

      * Ensures that we have a large enough buffer for the given size.

      */

     private void verifyBufferSize(int sz) {

         if (sz > buf.length) {

             byte[] old = buf;

             buf = new byte[Math.max(sz, 2 * buf.length )];

             System.arraycopy(old, 0, buf, 0, old.length);

             old = null;

         }

     }

     public int getSize() {

         return size;

     }

     /**

      * Returns the byte array containing the written data. Note that this

      * array will almost always be larger than the amount of data actually

      * written.

      */

     public byte[] getByteArray() {

         return buf;

     }

     public final void write(byte b[]) {

         verifyBufferSize(size + b.length);

         System.arraycopy(b, 0, buf, size, b.length);

         size += b.length;

     }

     public final void write(byte b[], int off, int len) {

         verifyBufferSize(size + len);

         System.arraycopy(b, off, buf, size, len);

         size += len;

     }

     public final void write(int b) {

         verifyBufferSize(size + 1);

         buf[size++] = (byte) b;

     }

     public void reset() {

         size = 0;

     }

     /**

      * Returns a ByteArrayInputStream for reading back the written data

      */

     public InputStream getInputStream() {

         return new FastByteArrayInputStream(buf, size);

     }

 }