/* this belongs to the WebRaveler package */
package webraveler.io;

import java.io.*;

/**
 * OutputStream that uses Chunked encoding
 *
 * @author The Web Raveler Development Squad
 * @version 1.0
 */

public class ChunkedOutputStream extends OutputStream{
    /* instance variables */
    OutputStream output;
    int count= 0;
    boolean closed= false;
    byte buf[];

    /* constructors */
    /**
     *
     */
    public ChunkedOutputStream(OutputStream out){
	output= out;
	buf= new byte[1024];
    }

    /* instance methods */
    /**
     * Closes the output stream and forces any buffered output bytes to be written out.
     */
    public void close() throws IOException{
	flush();
	output.write("0\r\n\r\n\r\n".getBytes());
	output.flush();
    }

    /**
     * Flushes the output stream and forces any buffered output bytes to be written out.
     */
    public void flush() throws IOException{
	sendBuffer(buf, 0, count);
	count= 0;
	output.flush();
    }

    /**
     * Writes a specified length of bytes to the output stream starting at the offset
     *
     * @param b a byte array to be written on the output stream
     * @param offset an integer representing the offset
     * @param length an integer representing the length to be written
     */
    public void sendBuffer(byte[] b, int offset, int length) throws IOException{
	if( length <= 0 ) return;
	output.write(Integer.toHexString(length).getBytes());
	output.write("\r\n".getBytes());
	output.write(b,offset,length);
	output.write("\r\n".getBytes());
    }

    /**
     * Writes a byte to the output stream
     *
     * @param c an integer representing the byte to be written
     */
    public void write(int c) throws IOException{
	if( closed ) throw new IOException();
	if( count < buf.length){
	    buf[count++]= (byte)c;
	} else {
	    sendBuffer(buf, 0, count);
	    count= 0;
	    write(c);
	}
    }


    /**
     * Writes the specified bytes to the output stream
     *
     * @param b a byte array to be written on the output stream
     * @param offset an integer representing the offset
     * @param length an integer representing the length to be written
     */
    public void write(byte[] source, int offset, int length) throws IOException{
	sendBuffer(buf,0,count);
	count= 0;
	sendBuffer(source, offset, length);
    }
}