jpexs-decompiler/libsrc/ffdec_lib/src/com/jpexs/helpers/LimitedInputStream.java

/*
 *  Copyright (C) 2010-2016 JPEXS, All rights reserved.
 *
 * 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 3.0 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 library.
 */
package com.jpexs.helpers;

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

/**
 *
 * @author JPEXS
 */
public class LimitedInputStream extends InputStream {

    private final InputStream is;

    private long pos = 0;

    private final long limit;

    public LimitedInputStream(InputStream is, long limit) {
        this.is = is;
        this.limit = limit;
    }

    @Override
    public int read() throws IOException {
        if (pos >= limit) {
            return -1;
        }
        pos++;
        return is.read();
    }

    @Override
    public int available() throws IOException {
        int avail = is.available();
        if (pos + avail > limit) {
            avail = (int) (limit - pos);
        }
        return avail;
    }
}