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

Class SimpleFastItemIndex<I>

java.lang.Object

es.uam.eps.ir.ranksys.fast.index.SimpleFastItemIndex<I>

Type Parameters:

I - type of the items

All Implemented Interfaces:

ItemIndex<I>, FastItemIndex<I>, Serializable

public class SimpleFastItemIndex<I>
extends Object
implements FastItemIndex<I>, Serializable

Simple implementation of FastItemIndex backed by a bi-map IdxIndex

Author:

Saúl Vargas (saul.vargas@uam.es)

See Also:

Serialized Form

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	SimpleFastItemIndex() Constructor.

Method Summary

Modifier and Type	Method and Description
protected int	add(I i) Add a new item to the index.
boolean	containsItem(I i) Checks whether the index contains an item.
Stream<I>	getAllItems() Retrieves a stream of the indexed items.
I	iidx2item(int iidx) Returns the item represented with the index.
int	item2iidx(I i) Returns the index assigned to the item.
static <I> SimpleFastItemIndex<I>	load(Stream<I> items) Creates an item index from a stream of item objects.
int	numItems() Counts the number of indexed items.

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.FastItemIndex

getAllIidx, iidx2item, iidx2item, item2iidx, item2iidx

Constructor Detail

SimpleFastItemIndex

protected SimpleFastItemIndex()

Constructor.

Method Detail

containsItem

public boolean containsItem(I i)

Description copied from interface: ItemIndex

Checks whether the index contains an item.

Specified by:

containsItem in interface ItemIndex<I>

Specified by:

containsItem in interface FastItemIndex<I>

Parameters:

i - item

Returns:

true if the index contains the item, false otherwise

numItems

public int numItems()

Description copied from interface: ItemIndex

Counts the number of indexed items.

Specified by:

numItems in interface ItemIndex<I>

Returns:

the total number of item

getAllItems

public Stream<I> getAllItems()

Description copied from interface: ItemIndex

Retrieves a stream of the indexed items.

Specified by:

getAllItems in interface ItemIndex<I>

Specified by:

getAllItems in interface FastItemIndex<I>

Returns:

a stream of all the items

item2iidx

public int item2iidx(I i)

Description copied from interface: FastItemIndex

Returns the index assigned to the item.

Specified by:

item2iidx in interface FastItemIndex<I>

Parameters:

i - item

Returns:

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

iidx2item

public I iidx2item(int iidx)

Description copied from interface: FastItemIndex

Returns the item represented with the index.

Specified by:

iidx2item in interface FastItemIndex<I>

Parameters:

iidx - item index

Returns:

the item whose index is iidx

add

protected int add(I i)

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

Parameters:

i - id of the item

Returns:

index of the item

load

public static <I> SimpleFastItemIndex<I> load(Stream<I> items)

Creates an item index from a stream of item objects.

Type Parameters:

I - type of the items

Parameters:

items - stream of item objects

Returns:

a fast item index