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The DSI utilities are a mishmash of classes accumulated during the last twenty years in projects developed at the DSI (Dipartimento di Scienze dell'Informazione, i.e., Information Sciences Department), now DI (Dipartimento di Informatica, i.e., Informatics Department), of the Universita` degli Studi di Milano.

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/*
 * DSI utilities
 *
 * Copyright (C) 2003-2020 Sebastiano Vigna
 *
 *  This library is free software; you can redistribute it and/or modify it
 *  under the terms of the GNU Lesser General Public License as published by the Free
 *  Software Foundation; either version 3 of the License, or (at your option)
 *  any later version.
 *
 *  This library is distributed in the hope that it will be useful, but
 *  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 *  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
 *  for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with this program; if not, see .
 *
 */

package it.unimi.dsi.io;

import java.io.IOException;
import java.io.OutputStream;

import it.unimi.dsi.fastutil.io.RepositionableStream;

/** Throw-it-away output stream.
 *
 * This stream discards whatever is written into it. Its usefulness is in
 * previewing the length of some coding by wrapping it in an {@link
 * OutputBitStream} (it is a good idea, in this case, {@linkplain
 * OutputBitStream#OutputBitStream(java.io.OutputStream,int) to specify a 0-length buffer}).
 *
 * This class is a singleton. You cannot create a null output stream,
 * but you can obtain an instance of this class using {@link #getInstance()}.
 *
 * @author Sebastiano Vigna
 * @since 0.6
 */

public class NullOutputStream extends OutputStream implements RepositionableStream {

	private final static NullOutputStream SINGLETON = new NullOutputStream();

	private NullOutputStream() {}

	@Override
	public void write(final int discarded) {}

	/** Returns the only instance of this class. */
	public static NullOutputStream getInstance() {
		return SINGLETON;
	}

	@Override
	public long position() throws IOException {
		return 0;
	}

	@Override
	public void position(final long newPosition) throws IOException {}
}