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

Class SimpleFastUserIndex<U>

java.lang.Object

es.uam.eps.ir.ranksys.fast.index.SimpleFastUserIndex<U>

Type Parameters:

U - type of the users

All Implemented Interfaces:

UserIndex<U>, FastUserIndex<U>, Serializable

public class SimpleFastUserIndex<U>
extends Object
implements FastUserIndex<U>, Serializable

Simple implementation of FastUserIndex 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	SimpleFastUserIndex() Empty constructor: no users.

Method Summary

Modifier and Type	Method and Description
protected int	add(U u) Add a new user to the index.
boolean	containsUser(U u) Checks whether the index contains a user.
Stream<U>	getAllUsers() Retrieves a stream of the indexed users.
static <U> SimpleFastUserIndex<U>	load(Stream<U> users) Creates a user index from a stream of user objects.
int	numUsers() Counts the number of indexed users.
U	uidx2user(int uidx) Returns the user represented with the index.
int	user2uidx(U u) Returns the index assigned to the user.

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.FastUserIndex

getAllUidx, uidx2user, uidx2user, user2uidx, user2uidx

Constructor Detail

SimpleFastUserIndex

protected SimpleFastUserIndex()

Empty constructor: no users.

Method Detail

containsUser

public boolean containsUser(U u)

Description copied from interface: UserIndex

Checks whether the index contains a user.

Specified by:

containsUser in interface UserIndex<U>

Specified by:

containsUser in interface FastUserIndex<U>

Parameters:

u - user

Returns:

true if the index contains the user, false otherwise

numUsers

public int numUsers()

Description copied from interface: UserIndex

Counts the number of indexed users.

Specified by:

numUsers in interface UserIndex<U>

Returns:

the total number of users

getAllUsers

public Stream<U> getAllUsers()

Description copied from interface: UserIndex

Retrieves a stream of the indexed users.

Specified by:

getAllUsers in interface UserIndex<U>

Specified by:

getAllUsers in interface FastUserIndex<U>

Returns:

a stream of all the users

user2uidx

public int user2uidx(U u)

Description copied from interface: FastUserIndex

Returns the index assigned to the user.

Specified by:

user2uidx in interface FastUserIndex<U>

Parameters:

u - user

Returns:

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

uidx2user

public U uidx2user(int uidx)

Description copied from interface: FastUserIndex

Returns the user represented with the index.

Specified by:

uidx2user in interface FastUserIndex<U>

Parameters:

uidx - user index

Returns:

the user whose index is uidx

add

protected int add(U u)

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

Parameters:

u - id of the user

Returns:

index of the user

load

public static <U> SimpleFastUserIndex<U> load(Stream<U> users)

Creates a user index from a stream of user objects.

Type Parameters:

U - type of the users

Parameters:

users - stream of user objects

Returns:

a fast user index