/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 2000-2003
* Sleepycat Software. All rights reserved.
*
* $Id: TupleSerialBinding.java,v 1.7 2003/10/22 14:28:39 mhayes Exp $
*/
package com.sleepycat.bdb.bind.serial;
import com.sleepycat.bdb.bind.DataBuffer;
import com.sleepycat.bdb.bind.DataFormat;
import com.sleepycat.bdb.bind.EntityBinding;
import com.sleepycat.bdb.bind.serial.SerialFormat;
import com.sleepycat.bdb.bind.tuple.TupleFormat;
import com.sleepycat.bdb.bind.tuple.TupleInput;
import com.sleepycat.bdb.bind.tuple.TupleOutput;
import java.io.IOException;
/**
* A abstract entity binding that uses a tuple key and a serial value. This
* class takes care of serializing and deserializing the value data,
* and converting the key data to/from {@link TupleInput} and {@link
* TupleOutput} objects. Its three abstract methods must be implemented by a
* concrete subclass to convert these objects to/from an entity object.
* <ul>
* <li> {@link #dataToObject(TupleInput,Object)} </li>
* <li> {@link #objectToKey(Object,TupleOutput)} </li>
* <li> {@link #objectToValue(Object)} </li>
* </ul>
*
* @author Mark Hayes
*/
public abstract class TupleSerialBinding implements EntityBinding {
protected TupleFormat keyFormat;
protected SerialFormat valueFormat;
/**
* Creates a tuple-serial entity binding.
*
* @param keyFormat is the key format.
*
* @param valueFormat is the value format.
*/
public TupleSerialBinding(TupleFormat keyFormat,
SerialFormat valueFormat) {
this.keyFormat = keyFormat;
this.valueFormat = valueFormat;
}
// javadoc is inherited
public Object dataToObject(DataBuffer key, DataBuffer value)
throws IOException {
return dataToObject(keyFormat.dataToInput(key),
valueFormat.dataToObject(value));
}
// javadoc is inherited
public void objectToKey(Object object, DataBuffer key)
throws IOException {
TupleOutput output = keyFormat.newOutput();
objectToKey(object, output);
keyFormat.outputToData(output, key);
}
// javadoc is inherited
public void objectToValue(Object object, DataBuffer value)
throws IOException {
object = objectToValue(object);
valueFormat.objectToData(object, value);
}
// javadoc is inherited
public DataFormat getKeyFormat() {
return keyFormat;
}
// javadoc is inherited
public DataFormat getValueFormat() {
return valueFormat;
}
/**
* Constructs an entity object from {@link TupleInput} key data and
* deserialized value data objects.
*
* @param keyInput is the {@link TupleInput} key data object.
*
* @param valueInput is the deserialized value data object.
*
* @return the entity object constructed from the key and value.
*
* @throws IOException if data cannot be read or written.
*/
public abstract Object dataToObject(TupleInput keyInput, Object valueInput)
throws IOException;
/**
* Extracts a key tuple from an entity object.
*
* @param object is the entity object.
*
* @param output is the {@link TupleOutput} to which the key should be
* written.
*
* @throws IOException if data cannot be read or written.
*/
public abstract void objectToKey(Object object, TupleOutput output)
throws IOException;
/**
* Extracts a value object from an entity object.
*
* @param object is the entity object.
*
* @return the deserialized value data object.
*
* @throws IOException if data cannot be read or written.
*/
public abstract Object objectToValue(Object object)
throws IOException;
}