/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is HTML Parser C++ Translator code.
 *
 * The Initial Developer of the Original Code is
 * Mozilla Foundation.
 * Portions created by the Initial Developer are Copyright (C) 2010
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Henri Sivonen <hsivonen@iki.fi>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

package nu.validator.htmlparser.cpptranslate;

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

public class CppOnlyInputStream extends InputStream {

    private static final String DROP = "// CPPONLY:";
    
    private final InputStream delegate;
    
    public CppOnlyInputStream(InputStream delegate) {
        this.delegate = new BufferedInputStream(delegate);
    }

    @Override public int read() throws IOException {
        int c = delegate.read();
        if (c == DROP.charAt(0)) {
            delegate.mark(DROP.length());
            for (int i = 1; i < DROP.length(); ++i) {
                int d = delegate.read();
                if (d != DROP.charAt(i)) {
                    delegate.reset();
                    return c;
                }
            }
            return delegate.read();
        }
        return c;
    }

}