001    /**
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    package org.apache.kahadb.util;
018    
019    import java.io.DataInput;
020    import java.io.DataOutput;
021    import java.io.IOException;
022    
023    /**
024     * @version $Revision: 816280 $
025     */
026    public interface Marshaller<T> {
027        
028        /**
029         * Write the payload of the object to the DataOutput stream.
030         * 
031         * @param object 
032         * @param dataOut
033         * @throws IOException
034         */
035        void writePayload(T object, DataOutput dataOut) throws IOException;
036        
037        
038        /**
039         * Read the payload of the object from the DataInput stream.
040         * 
041         * @param dataIn 
042         * @return unmarshalled object
043         * @throws IOException
044         */
045        T readPayload(DataInput dataIn) throws IOException;
046    
047        /** 
048         * @return -1 if the object do not always marshall to a fixed size, otherwise return that fixed size.
049         */
050        int getFixedSize();
051        
052        /**
053         * 
054         * @return true if the {@link #deepCopy(Object)} operations is supported.
055         */
056        boolean isDeepCopySupported();
057    
058        /**
059         * @return a deep copy of the source object.
060         */
061        T deepCopy(T source);
062       
063    }