es.uam.eps.ir.ranksys.fast.utils

Class IdxIndex<T>

java.lang.Object

es.uam.eps.ir.ranksys.fast.utils.IdxIndex<T>

Type Parameters:

T - type of the user/item/feature

All Implemented Interfaces:

Serializable

public class IdxIndex<T>
extends Object
implements Serializable

Bi-map-like structure to back fast version of user/item/feature indexes. It keeps to maps: id-to-index and index-to-id. Value of indexes go from 0 (included) to the number of elements (excluded).

Author:

Saúl Vargas (saul.vargas@uam.es)

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
IdxIndex() Constructor.

Method Summary

Modifier and Type	Method and Description
int	add(T t) Adds an element to the structure.
boolean	containsId(T t) Checks whether the structure contains this element.
T	get(int idx) Gets the element assigned to the index.
int	get(T t) Gets the index of the element.
Stream<T>	getIds() Returns a stream of the elements stored in the structure.
int	size() Returns the number of stored elements.

Methods inherited from class java.lang.Object

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

Constructor Detail

IdxIndex

public IdxIndex()

Constructor.

Method Detail

add

public int add(T t)

Adds an element to the structure.

Parameters:

t - element to be added

Returns:

the index of the element

get

public int get(T t)

Gets the index of the element.

Parameters:

t - element

Returns:

index of the element

get

public T get(int idx)

Gets the element assigned to the index.

Parameters:

idx - index

Returns:

the element whose index is idx

containsId

public boolean containsId(T t)

Checks whether the structure contains this element.

Parameters:

t - element

Returns:

does the structure contain this element?

size

public int size()

Returns the number of stored elements.

Returns:

the number of stored elements

getIds

public Stream<T> getIds()

Returns a stream of the elements stored in the structure.

Returns:

a stream of the elements stored in the structure