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A pluggable BSON generator and parser for Jackson JSON processor.

There is a newer version: 2.9.2

package de.undercouch.bson4jackson.io;

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

/**
 * Reads from another input stream, but counts the number of
 * bytes read or skipped (i.e. saves the current buffer position).
 * @author Michel Kraemer
 */
public class CountingInputStream extends FilterInputStream {
    /**
     * The current buffer position
     */
    protected int _pos;

    /**
     * The position in the buffer the last time {@link #mark(int)} was called
     */
    protected int _markpos = -1;

    /**
     * @see FilterInputStream#FilterInputStream(InputStream)
     */
    public CountingInputStream(InputStream in) {
        super(in);
    }

    /**
     * @return the number of bytes read or skipped
     */
    public int getPosition() {
        return _pos;
    }

    @Override
    public int read() throws IOException {
        int r = super.read();
        if (r >= 0) {
            ++_pos;
        }
        return r;
    }

    @Override
    public int read(byte[] b) throws IOException {
        int r = super.read(b);
        if (r > 0) {
            _pos += r;
        }
        return r;
    }

    @Override
    public int read(byte[] b, int off, int len) throws IOException {
        int r = super.read(b, off, len);
        if (r > 0) {
            _pos += r;
        }
        return r;
    }

    @Override
    public long skip(long n) throws IOException {
        long r = super.skip(n);
        if (r > 0) {
            _pos += r;
        }
        return r;
    }

    @Override
    public synchronized void mark(int readlimit) {
        _markpos = _pos;
        super.mark(readlimit);
    }

    @Override
    public synchronized void reset() throws IOException {
        super.reset();
        _pos = _markpos;
    }
}