/***********************************************************************************************************************
* Copyright (C) 2010-2013 by the Stratosphere project (http://stratosphere.eu)
*
* Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
* an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
* specific language governing permissions and limitations under the License.
**********************************************************************************************************************/
package eu.stratosphere.nephele.services.iomanager;
import java.io.DataInput;
import java.io.IOException;
/**
* <p>
* Provides a facility for deserializing objects of type <T> from an {@link InputStream}.
* </p>
* <p>
* Deserializers are stateful, but must not buffer the input since other producers may read from the input between calls
* to {@link #deserialize(Object)}.
* </p>
*
* @param <T>
*/
public interface Deserializer<T> {
/**
* <p>
* Prepare the deserializer for reading.
* </p>
*/
void open(DataInput in) throws IOException;
/**
* <p>
* Deserialize the next object from the underlying input stream. If the object <code>t</code> is non-null then this
* deserializer <i>may</i> set its internal state to the next object read from the input stream. Otherwise, if the
* object <code>t</code> is null a new deserialized object will be created.
* </p>
*
* @return the deserialized object
*/
T deserialize(T t) throws IOException;
/**
* <p>
* Clear up any resources.
* </p>
*/
void close() throws IOException;
}