/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 2000,2007 Oracle. All rights reserved.
*
* $Id: TupleTupleKeyCreator.java,v 12.7 2007/05/04 00:28:25 mark Exp $
*/
package com.sleepycat.bind.tuple;
import com.sleepycat.db.DatabaseEntry;
import com.sleepycat.db.DatabaseException;
import com.sleepycat.db.SecondaryDatabase;
import com.sleepycat.db.SecondaryKeyCreator;
/**
* An abstract key creator that uses a tuple key and a tuple data entry. This
* class takes care of converting the key and data entry to/from {@link
* TupleInput} and {@link TupleOutput} objects.
* The following abstract method must be implemented by a concrete subclass
* to create the index key using these objects
*
* - {@link #createSecondaryKey(TupleInput,TupleInput,TupleOutput)}
*
*
* @author Mark Hayes
*/
public abstract class TupleTupleKeyCreator extends TupleBase
implements SecondaryKeyCreator {
/**
* Creates a tuple-tuple key creator.
*/
public TupleTupleKeyCreator() {
}
// javadoc is inherited
public boolean createSecondaryKey(SecondaryDatabase db,
DatabaseEntry primaryKeyEntry,
DatabaseEntry dataEntry,
DatabaseEntry indexKeyEntry)
throws DatabaseException {
TupleOutput output = getTupleOutput(null);
TupleInput primaryKeyInput = entryToInput(primaryKeyEntry);
TupleInput dataInput = entryToInput(dataEntry);
if (createSecondaryKey(primaryKeyInput, dataInput, output)) {
outputToEntry(output, indexKeyEntry);
return true;
} else {
return false;
}
}
// javadoc is inherited
public boolean nullifyForeignKey(SecondaryDatabase db,
DatabaseEntry dataEntry)
throws DatabaseException {
TupleOutput output = getTupleOutput(null);
if (nullifyForeignKey(entryToInput(dataEntry), output)) {
outputToEntry(output, dataEntry);
return true;
} else {
return false;
}
}
/**
* Creates the index key from primary key tuple and data tuple.
*
* @param primaryKeyInput is the {@link TupleInput} for the primary key
* entry.
*
* @param dataInput is the {@link TupleInput} for the data entry.
*
* @param indexKeyOutput is the destination index key tuple.
*
* @return true if a key was created, or false to indicate that the key is
* not present.
*/
public abstract boolean createSecondaryKey(TupleInput primaryKeyInput,
TupleInput dataInput,
TupleOutput indexKeyOutput);
/**
* Clears the index key in the tuple data entry. The dataInput should be
* read and then written to the dataOutput, clearing the index key in the
* process.
*
* The secondary key should be output or removed by this method such
* that {@link #createSecondaryKey} will return false. Other fields in the
* data object should remain unchanged.
*
* @param dataInput is the {@link TupleInput} for the data entry.
*
* @param dataOutput is the destination {@link TupleOutput}.
*
* @return true if the key was cleared, or false to indicate that the key
* is not present and no change is necessary.
*/
public boolean nullifyForeignKey(TupleInput dataInput,
TupleOutput dataOutput) {
return false;
}
}