/*
 * 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.IOException;
import java.io.OutputStream;

/**
 * A class that buffers writte without synchronize its methods
 * @author raul
 *
 */
public class UnsyncBufferedOutputStream extends OutputStream {
	final OutputStream out;
	
	final byte[] buf;
	static final int size=8*1024;
	private static ThreadLocal bufCahce = new ThreadLocal() {
        protected synchronized Object initialValue() {
            return new byte[size];
        }
    };
	int pointer=0;
	/**
	 * Creates a buffered output stream without synchronization
	 * @param out the outputstream to buffer
	 */
	public UnsyncBufferedOutputStream(OutputStream out) {
		buf=(byte[])bufCahce.get();
		this.out=out;
	}
	
	/** @inheritDoc */
	public void write(byte[] arg0) throws IOException {
		write(arg0,0,arg0.length);
	}
	
	/** @inheritDoc */
	public void write(byte[] arg0, int arg1, int len) throws IOException {
		int newLen=pointer+len;
		if (newLen> size) {
			flushBuffer();		
			if (len>size) {
				out.write(arg0,arg1,len);
				return;
			}
			newLen=len;
		}
		System.arraycopy(arg0,arg1,buf,pointer,len);
		pointer=newLen;
	}
	
	private final void flushBuffer() throws IOException {
		if (pointer>0)
			out.write(buf,0,pointer);
		pointer=0;
		
	}
	
	/** @inheritDoc */
	public void write(int arg0) throws IOException {		
		if (pointer>= size) {
			flushBuffer();
		}
		buf[pointer++]=(byte)arg0;

	}
	
	/** @inheritDoc */	
	public void flush() throws IOException {
		flushBuffer();
		out.flush();
	}

	/** @inheritDoc */
	public void close() throws IOException {
		flush();				
	}

}