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 * Copyright (c) 2012, THE BOARD OF TRUSTEES OF THE LELAND STANFORD JUNIOR UNIVERSITY
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 *    may be used to endorse or promote products derived from this software without
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package org.cyclades.io;

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

public abstract class PeekingOutputStream extends OutputStream {

    public PeekingOutputStream (OutputStream out, char peekChar) {
        this.out = out;
        this.peekChar = peekChar;
    }

    @Override
    public void write(int toWrite) throws IOException {
        if (!hasPeeked) {
            peekBuffer.write(toWrite);
            if ((char)toWrite == peekChar) {
                byte[] data = peekBuffer.toByteArray();
                peek(data);
                hasPeeked = true;
                peekBuffer = null;
                out.write(data);
            }
        } else {
            out.write(toWrite);
        }
    }

    public abstract void peek (byte[] data) throws PeekException;

    private final OutputStream out;
    private final char peekChar;
    private ByteArrayOutputStream peekBuffer = new ByteArrayOutputStream();
    private boolean hasPeeked = false;
}