/*
 * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
 * 
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * The contents of this file are subject to the terms of either the Universal Permissive License
 * v 1.0 as shown at http://oss.oracle.com/licenses/upl
 *
 * or the following license:
 *
 * Redistribution and use in source and binary forms, with or without modification, are permitted
 * provided that the following conditions are met:
 * 
 * 1. Redistributions of source code must retain the above copyright notice, this list of conditions
 * and the following disclaimer.
 * 
 * 2. Redistributions in binary form must reproduce the above copyright notice, this list of
 * conditions and the following disclaimer in the documentation and/or other materials provided with
 * the distribution.
 * 
 * 3. Neither the name of the copyright holder nor the names of its contributors may be used to
 * endorse or promote products derived from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 */
package org.openjdk.jmc.joverflow.heap.parser;

import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;

/**
 * InputStream that keeps track of total bytes read (in effect 'position' in stream) from the input
 * stream.
 */
public class PositionInputStream extends FilterInputStream {
	private long position = 0L;

	public PositionInputStream(InputStream in) {
		super(in);
	}

	@Override
	public int read() throws IOException {
		int res = super.read();
		if (res != -1) {
			position++;
		}
		return res;
	}

	@Override
	public int read(byte[] b, int off, int len) throws IOException {
		int res = super.read(b, off, len);
		if (res != -1) {
			position += res;
		}
		return res;
	}

	@Override
	public long skip(long n) throws IOException {
		long res = super.skip(n);
		position += res;
		return res;
	}

	@Override
	public boolean markSupported() {
		return false;
	}

	@Override
	public void mark(int readLimit) {
		throw new UnsupportedOperationException("mark");
	}

	@Override
	public void reset() {
		throw new UnsupportedOperationException("reset");
	}

	public long position() {
		return position;
	}
}
