/*
 * Copyright  1999-2005 The Apache Software Foundation.
 *
 *  Licensed under the Apache 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.apache.org/licenses/LICENSE-2.0
 *
 *  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.apache.xml.security.utils;

import java.io.OutputStream;

/**
 * A simple Unsynced ByteArryOutputStream
 * @author raul
 *
 */
public class UnsyncByteArrayOutputStream extends OutputStream  {	
	private static ThreadLocal bufCahce = new ThreadLocal() {
        protected synchronized Object initialValue() {
            return new byte[8*1024];
        }        
    };
    byte[] buf;
	int size=8*1024;//buf.length;	
	int pos=0;
	/** @inheritDoc */
	public UnsyncByteArrayOutputStream() {
		buf=(byte[])bufCahce.get();
	}
	public void write(byte[] arg0) {
		int newPos=pos+arg0.length;
		if (newPos>size) {
			expandSize();
		}
		System.arraycopy(arg0,0,buf,pos,arg0.length);
		pos=newPos;
	}
	/** @inheritDoc */
	public void write(byte[] arg0, int arg1, int arg2) {
		int newPos=pos+arg2;
		if (newPos>size) {
			expandSize();
		}
		System.arraycopy(arg0,arg1,buf,pos,arg2);
		pos=newPos;
	}
	/** @inheritDoc */
	public void write(int arg0) {		
		if (pos>=size) {
			expandSize();
		}
		buf[pos++]=(byte)arg0;		
	}
	/** @inheritDoc */
	public byte[] toByteArray() {
		byte result[]=new byte[pos];
		System.arraycopy(buf,0,result,0,pos);
		return result;
	}
	
	/** @inheritDoc */
	public void reset() {
		pos=0;
	}
	
	/** @inheritDoc */
	void expandSize() {
		int newSize=size<<2;
		byte newBuf[]=new byte[newSize];
		System.arraycopy(buf,0,newBuf,0,pos);		
		buf=newBuf;
		size=newSize;
		
	}
}