net.obsearch.index.pivot
Class AbstractPivotOBIndex<O extends OB>

java.lang.Object
  net.obsearch.index.AbstractOBIndex<O>
      net.obsearch.index.pivot.AbstractPivotOBIndex<O>

All Implemented Interfaces:

Index<O>

Direct Known Subclasses:

AbstractBucketIndex

public abstract class AbstractPivotOBIndex<O extends OB>
extends AbstractOBIndex<O>

AbstractPivotOBIndex defines abstract functionality for an index that uses n pivots to partition the data into more tractable subsets. To create a new index, do the following: 1) Implement objectToProjectionBytes(O object) (smap an object and codify it) 2) Implement deleteAux 3) Implement insertAux 4) Implement searchOB. That's all!

Author:

Arnoldo Jose Muller Molina

Field Summary

protected int	intrinsicDimensionalityPairs Use the following amount of pairs when the intrinsic dimensionality is calculated.
protected O[]	pivots The pivots for this Tree.
protected IncrementalPivotSelector<O>	pivotSelector The pivot selector used by the index.

Fields inherited from class net.obsearch.index.AbstractOBIndex

A, fact, isFrozen, stats, type

Fields inherited from interface net.obsearch.Index

ID_SIZE

Constructor Summary

protected	AbstractPivotOBIndex()
protected	AbstractPivotOBIndex(Class<O> type, IncrementalPivotSelector<O> pivotSelector, int pivotCount) Creates an index that uses pivots as its major data partitioning strategy.

Method Summary

protected double	calculateIntrinsicDimensionality() Calculates the intrinsic dimensionality of the inserted dataset.
protected void	createPivotsArray(int size) Creates an array with the pivots.
void	freeze() Freezes the index.
protected O[]	getObjects(long[] ids) Stores the given pivots in a local array.
int	getPivotCount()
void	init(OBStoreFactory fact) Initialize the index.
protected PivotResult	selectPivots(int pivotCount, IncrementalPivotSelector<O> pivotSelector) Override this method if selection must be changed

Methods inherited from class net.obsearch.index.AbstractOBIndex

assertFrozen, bytesToObject, bytesToObject, clearACache, close, databaseSize, debug, delete, deleteAux, distance, emptyPivotsArray, findAux, getBox, getObject, getStats, getType, initCache, initStorageDevices, insert, insert, insertAux, insertAuxBulk, insertBulk, insertBulk, intrinsicDimensionality, isFrozen, isPreFreeze, isPreFreezeCheck, loadObject, loadPivots, objectToByteBuffer, objectToBytes, resetStats, serializePivots, setFixedRecord, setFixedRecord, setIdAutoGeneration, setPreFreeze, setPreFreezeCheck, totalBoxes

Methods inherited from class java.lang.Object

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

Methods inherited from interface net.obsearch.Index

exists

Field Detail

pivotSelector

protected IncrementalPivotSelector<O extends OB> pivotSelector

The pivot selector used by the index.

pivots

protected O extends OB[] pivots

The pivots for this Tree. When we instantiate or de-serialize this object we load them from #pivotsBytes.

intrinsicDimensionalityPairs

protected int intrinsicDimensionalityPairs

Use the following amount of pairs when the intrinsic dimensionality is calculated.

Constructor Detail

AbstractPivotOBIndex

protected AbstractPivotOBIndex(Class<O> type,
                               IncrementalPivotSelector<O> pivotSelector,
                               int pivotCount)
                        throws OBStorageException,
                               OBException

Creates an index that uses pivots as its major data partitioning strategy.

Parameters:

type - The type of object that will be stored.

pivotSelector - The pivot selection strategy to be employed.

pivotCount - The number of pivots that will be selected.

Throws:

OBStorageException

OBException

AbstractPivotOBIndex

protected AbstractPivotOBIndex()

Method Detail

freeze

public void freeze()
            throws AlreadyFrozenException,
                   IllegalIdException,
                   IllegalAccessException,
                   InstantiationException,
                   OBStorageException,
                   OutOfRangeException,
                   OBException,
                   PivotsUnavailableException,
                   IOException

Description copied from interface: Index

Freezes the index. From this point data can be inserted, searched and deleted. The index might deteriorate at some point so every once in a while it is a good idea to rebuild the index. A PivotSelector must be executed before calling this method.

Specified by:

freeze in interface Index<O extends OB>

Overrides:

freeze in class AbstractOBIndex<O extends OB>

Throws:

AlreadyFrozenException - If the index was already frozen and the user attempted to freeze it again

IllegalIdException - This exception is left as a Debug flag. If you receive this exception please report the problem to: http://code.google.com/p/obsearch/issues/list

IllegalAccessException - If there is a problem when instantiating objects O

InstantiationException - If there is a problem when instantiating objects O

OBStorageException - If something goes wrong with the DB

OutOfRangeException - If the distance of any object to any other object exceeds the range defined by the user.

OBException - User generated exception

PivotsUnavailableException

IOException - if the index serialization process fails

See Also:

Index.freeze()

calculateIntrinsicDimensionality

protected double calculateIntrinsicDimensionality()
                                           throws IllegalIdException,
                                                  IllegalAccessException,
                                                  InstantiationException,
                                                  OBException

Calculates the intrinsic dimensionality of the inserted dataset.

Returns:

Throws:

IllegalIdException

IllegalAccessException

InstantiationException

OBException

selectPivots

protected PivotResult selectPivots(int pivotCount,
                                   IncrementalPivotSelector<O> pivotSelector)
                            throws AlreadyFrozenException,
                                   IllegalIdException,
                                   IllegalAccessException,
                                   InstantiationException,
                                   OBStorageException,
                                   OutOfRangeException,
                                   OBException,
                                   IOException

Override this method if selection must be changed

Throws:

IOException

AlreadyFrozenException

IllegalIdException

IllegalAccessException

InstantiationException

OBStorageException

OutOfRangeException

OBException

getObjects

protected O[] getObjects(long[] ids)
                             throws IllegalIdException,
                                    IllegalAccessException,
                                    InstantiationException,
                                    OBException

Stores the given pivots in a local array. Takes the pivots from the database using the given ids.

Parameters:

ids - Ids of the pivots that will be stored.

Throws:

IllegalIdException - If the pivot selector generates invalid ids

com.sleepycat.je.DatabaseException - If something goes wrong with the DB

OBException - User generated exception

IllegalAccessException - If there is a problem when instantiating objects O

InstantiationException - If there is a problem when instantiating objects O

createPivotsArray

protected void createPivotsArray(int size)

Creates an array with the pivots. It has to be created like this because we are using generics. Subclasses must override this if different sets of pivots are to be used. We can override this later to have a multiple set of pivots for indexes like D...

getPivotCount

public int getPivotCount()

Returns:

The number of pivots used in this index.

init

public void init(OBStoreFactory fact)
          throws OBStorageException,
                 OBException,
                 NotFrozenException,
                 IllegalAccessException,
                 InstantiationException,
                 OBException

Description copied from class: AbstractOBIndex

Initialize the index.

Specified by:

init in interface Index<O extends OB>

Overrides:

init in class AbstractOBIndex<O extends OB>

Parameters:

fact - The storage factory that will be used to store the data.

Throws:

OBStorageException - If something goes wrong with the DB

OBException - User generated exception

NotFrozenException - if the index has not been frozen.

IllegalAccessException - If there is a problem when instantiating objects O

InstantiationException - If there is a problem when instantiating objects O