es.uam.eps.ir.ranksys.fast.index

Class SimpleFastFeatureIndex<F>

java.lang.Object

es.uam.eps.ir.ranksys.fast.index.SimpleFastFeatureIndex<F>

Type Parameters:

F - type of the features

All Implemented Interfaces:

FeatureIndex<F>, FastFeatureIndex<F>

public class SimpleFastFeatureIndex<F>
extends Object
implements FastFeatureIndex<F>

Simple implementation of FastFeatureIndex backed by a bi-map IdxIndex

Author:

Saúl Vargas (saul.vargas@uam.es)

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	SimpleFastFeatureIndex() Constructor.

Method Summary

Modifier and Type	Method and Description
protected int	add(F f) Add a new feature to the index.
boolean	containsFeature(F f) Checks whether the index contains a feature.
int	feature2fidx(F f) Returns the index assigned to the feature.
F	fidx2feature(int fidx) Returns the feature represented with the index.
Stream<F>	getAllFeatures() Retrieves a stream of the indexed features.
static <F> SimpleFastFeatureIndex<F>	load(Stream<F> features) Creates a feature index from a stream of feature objects.
int	numFeatures() Counts the number of indexed features.

Methods inherited from class java.lang.Object

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

Methods inherited from interface es.uam.eps.ir.ranksys.fast.index.FastFeatureIndex

feature2fidx, feature2fidx, fidx2feature, fidx2feature, getAllFidx

Constructor Detail

SimpleFastFeatureIndex

protected SimpleFastFeatureIndex()

Constructor.

Method Detail

containsFeature

public boolean containsFeature(F f)

Description copied from interface: FeatureIndex

Checks whether the index contains a feature.

Specified by:

containsFeature in interface FeatureIndex<F>

Specified by:

containsFeature in interface FastFeatureIndex<F>

Parameters:

f - feature

Returns:

true if the index contains the feature, false otherwise

numFeatures

public int numFeatures()

Description copied from interface: FeatureIndex

Counts the number of indexed features.

Specified by:

numFeatures in interface FeatureIndex<F>

Returns:

the total number of features

getAllFeatures

public Stream<F> getAllFeatures()

Description copied from interface: FeatureIndex

Retrieves a stream of the indexed features.

Specified by:

getAllFeatures in interface FeatureIndex<F>

Specified by:

getAllFeatures in interface FastFeatureIndex<F>

Returns:

a stream of all the features

feature2fidx

public int feature2fidx(F f)

Description copied from interface: FastFeatureIndex

Returns the index assigned to the feature.

Specified by:

feature2fidx in interface FastFeatureIndex<F>

Parameters:

f - feature

Returns:

the index of the feature, or -1 if the feature does not exist

fidx2feature

public F fidx2feature(int fidx)

Description copied from interface: FastFeatureIndex

Returns the feature represented with the index.

Specified by:

fidx2feature in interface FastFeatureIndex<F>

Parameters:

fidx - feature index

Returns:

the feature whose index is fidx

add

protected int add(F f)

Add a new feature to the index. If the feature already exists, nothing is done.

Parameters:

f - id of the feature

Returns:

index of the feature

load

public static <F> SimpleFastFeatureIndex<F> load(Stream<F> features)

Creates a feature index from a stream of feature objects.

Type Parameters:

F - type of the features

Parameters:

features - stream of feature objects

Returns:

a fast feature index