com.sleepycat.bind.tuple.MarshalledTupleKeyEntity Maven / Gradle / Ivy
/*-
* Copyright (C) 2002, 2018, Oracle and/or its affiliates. All rights reserved.
*
* This file was distributed by Oracle as part of a version of Oracle Berkeley
* DB Java Edition made available at:
*
* http://www.oracle.com/technetwork/database/database-technologies/berkeleydb/downloads/index.html
*
* Please see the LICENSE file included in the top-level directory of the
* appropriate version of Oracle Berkeley DB Java Edition for a copy of the
* license and additional information.
*/
package com.sleepycat.bind.tuple;
/**
* A marshalling interface implemented by entity classes that represent keys as
* tuples. Since MarshalledTupleKeyEntity objects are instantiated
* using Java deserialization, no particular constructor is required by classes
* that implement this interface.
*
* Note that a marshalled tuple key extractor is somewhat less efficient
* than a non-marshalled key tuple extractor because more conversions are
* needed. A marshalled key extractor must convert the entry to an object in
* order to extract the key fields, while an unmarshalled key extractor does
* not.
*
* @author Mark Hayes
* @see TupleTupleMarshalledBinding
* @see com.sleepycat.bind.serial.TupleSerialMarshalledBinding
*/
public interface MarshalledTupleKeyEntity {
/**
* Extracts the entity's primary key and writes it to the key output.
*
* @param keyOutput is the output tuple.
*/
void marshalPrimaryKey(TupleOutput keyOutput);
/**
* Completes construction of the entity by setting its primary key from the
* stored primary key.
*
* @param keyInput is the input tuple.
*/
void unmarshalPrimaryKey(TupleInput keyInput);
/**
* Extracts the entity's secondary key and writes it to the key output.
*
* @param keyName identifies the secondary key.
*
* @param keyOutput is the output tuple.
*
* @return true if a key was created, or false to indicate that the key is
* not present.
*/
boolean marshalSecondaryKey(String keyName, TupleOutput keyOutput);
/**
* Clears the entity's secondary key fields for the given key name.
*
* The specified index key should be changed by this method such that
* {@link #marshalSecondaryKey} for the same key name will return false.
* Other fields in the data object should remain unchanged.
*
* If {@link com.sleepycat.je.ForeignKeyDeleteAction#NULLIFY} was
* specified when opening the secondary database, this method is called
* when the entity for this foreign key is deleted. If NULLIFY was not
* specified, this method will not be called and may always return
* false.
*
* @param keyName identifies the secondary key.
*
* @return true if the key was cleared, or false to indicate that the key
* is not present and no change is necessary.
*/
boolean nullifyForeignKey(String keyName);
}