com.sleepycat.bind.serial
Class TupleSerialKeyCreator

java.lang.Object
  |
  +--com.sleepycat.bind.serial.TupleSerialKeyCreator

All Implemented Interfaces:

ForeignKeyNullifier, SecondaryKeyCreator

Direct Known Subclasses:

TupleSerialMarshalledKeyCreator

public abstract class TupleSerialKeyCreator

extends Object

implements SecondaryKeyCreator, ForeignKeyNullifier

A abstract key creator that uses a tuple key and a serial data entry. This class takes care of serializing and deserializing the data entry, and converting the key entry to/from TupleInput and TupleOutput objects. The following abstract method must be implemented by a concrete subclass to create the index key using these objects

• createSecondaryKey(TupleInput,Object,TupleOutput)

If ForeignKeyDeleteAction.NULLIFY was specified when opening the secondary database, the following method must be overridden to nullify the foreign index key. If NULLIFY was not specified, this method need not be overridden.

• nullifyForeignKey(Object)

Author:

Mark Hayes

Constructor Summary

TupleSerialKeyCreator(ClassCatalog classCatalog, Class dataClass)
Creates a tuple-serial key creator.

TupleSerialKeyCreator(SerialBinding dataBinding)
Creates a tuple-serial key creator.

Method Summary

boolean	createSecondaryKey(SecondaryDatabase db, DatabaseEntry primaryKeyEntry, DatabaseEntry dataEntry, DatabaseEntry indexKeyEntry) Creates a secondary key entry, given a primary key and data entry.
abstract boolean	createSecondaryKey(TupleInput primaryKeyInput, Object dataInput, TupleOutput indexKeyOutput) Creates the index key entry from primary key tuple entry and deserialized data entry.
Object	nullifyForeignKey(Object data) Clears the index key in the deserialized data entry.
boolean	nullifyForeignKey(SecondaryDatabase db, DatabaseEntry dataEntry) Sets the foreign key reference to null in the datum of the primary database.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

TupleSerialKeyCreator

public TupleSerialKeyCreator(ClassCatalog classCatalog,
                             Class dataClass)

Creates a tuple-serial key creator.

Parameters:

classCatalog - is the catalog to hold shared class information and for a database should be a StoredClassCatalog.

dataClass - is the data base class.

TupleSerialKeyCreator

public TupleSerialKeyCreator(SerialBinding dataBinding)

Creates a tuple-serial key creator.

Parameters:

dataBinding - is the data binding.

Method Detail

createSecondaryKey

public boolean createSecondaryKey(SecondaryDatabase db,
                                  DatabaseEntry primaryKeyEntry,
                                  DatabaseEntry dataEntry,
                                  DatabaseEntry indexKeyEntry)
                           throws DatabaseException

Description copied from interface: SecondaryKeyCreator

Creates a secondary key entry, given a primary key and data entry.

Specified by:

createSecondaryKey in interface SecondaryKeyCreator

Parameters:

db - the database to which the secondary key will be added.

primaryKeyEntry - the primary key entry. This parameter must not be modified by this method.

dataEntry - the primary data entry. This parameter must not be modified by this method.

indexKeyEntry - the secondary key created by this method.

Returns:

true if a key was created, or false to indicate that the key is not present.

Throws:

DatabaseException - if an error occurs attempting to create the secondary key.

nullifyForeignKey

public boolean nullifyForeignKey(SecondaryDatabase db,
                                 DatabaseEntry dataEntry)
                          throws DatabaseException

Description copied from interface: ForeignKeyNullifier

Sets the foreign key reference to null in the datum of the primary database.

Specified by:

nullifyForeignKey in interface ForeignKeyNullifier

Parameters:

db - the database in which the foreign key integrity constraint is defined.

dataEntry - the existing primary key datum in which the foreign key reference should be set to null.

Returns:

true if the datum was modified, or false to indicate that the key is not present.

Throws:

DatabaseException - if an error occurs attempting to clear the key reference.

createSecondaryKey

public abstract boolean createSecondaryKey(TupleInput primaryKeyInput,
                                           Object dataInput,
                                           TupleOutput indexKeyOutput)

Creates the index key entry from primary key tuple entry and deserialized data entry.

Parameters:

primaryKeyInput - is the TupleInput for the primary key entry, or null if no primary key entry is used to construct the index key.

dataInput - is the deserialized data entry, or null if no data entry is used to construct the index key.

indexKeyOutput - is the destination index key tuple. For index keys which are optionally present, no tuple entry should be output to indicate that the key is not present or null.

Returns:

true if a key was created, or false to indicate that the key is not present.

nullifyForeignKey

public Object nullifyForeignKey(Object data)

Clears the index key in the deserialized data entry.

On entry the data parameter contains the index key to be cleared. It should be changed by this method such that createSecondaryKey(com.sleepycat.je.SecondaryDatabase, com.sleepycat.je.DatabaseEntry, com.sleepycat.je.DatabaseEntry, com.sleepycat.je.DatabaseEntry) will return false. Other fields in the data object should remain unchanged.

Parameters:

data - is the source and destination deserialized data entry.

Returns:

the destination data object, or null to indicate that the key is not present and no change is necessary. The data returned may be the same object passed as the data parameter or a newly created object.