/***** BEGIN LICENSE BLOCK *****
 * Version: CPL 1.0/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Common Public
 * License Version 1.0 (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.eclipse.org/legal/cpl-v10.html
 *
 * 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.
 *
 * Copyright (C) 2002 Jan Arne Petersen <jpetersen@uni-bonn.de>
 * Copyright (C) 2002-2004 Anders Bengtsson <ndrsbngtssn@yahoo.se>
 * Copyright (C) 2004 Stefan Matthias Aust <sma@3plus4.de>
 * Copyright (C) 2007 Ola Bini <ola.bini@gmail.com>
 * 
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 * either of the GNU General Public License Version 2 or later (the "GPL"),
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package org.jruby.runtime.marshal;

import java.io.IOException;
import java.util.IdentityHashMap;
import java.util.Map;

import org.jruby.RubySymbol;
import org.jruby.runtime.builtin.IRubyObject;

public class MarshalCache {
    private Map linkCache = new IdentityHashMap();
    private Map symbolCache = new IdentityHashMap();

    public boolean isRegistered(IRubyObject value) {
        return selectCache(value).containsKey(value);
    }

    public void register(IRubyObject value) {
        Map cache = selectCache(value);
        cache.put(value, new Integer(cache.size()));
    }

    private int registeredIndex(IRubyObject value) {
        return ((Integer) selectCache(value).get(value)).intValue();
    }

    private Map selectCache(IRubyObject value) {
        return (value instanceof RubySymbol) ? symbolCache : linkCache;
    }

    public void writeLink(MarshalStream output, IRubyObject value) throws IOException {
        output.write(linkType(value));
        output.writeInt(registeredIndex(value));
    }

    private static char linkType(IRubyObject value) {
        return (value instanceof RubySymbol) ? ';' : '@';
    }
}
