Package org.basex.query.util.hash

Class HashItemSet

java.lang.Object

org.basex.util.hash.ASet

org.basex.query.util.hash.HashItemSet

All Implemented Interfaces:

Iterable<Item>, ItemSet

public class HashItemSet
extends ASet
implements ItemSet

This is an efficient and memory-saving hash set for storing items.

Author:

BaseX Team 2005-24, BSD License, Christian Gruen

Field Summary

Fields inherited from class org.basex.util.hash.ASet

buckets, next, size

Constructor Summary

Constructors

Constructor	Description
HashItemSet(boolean eq, InputInfo info)	Default constructor.

Method Summary

Modifier and Type	Method	Description
boolean	add(Item key)	Stores the specified key if it has not been stored before.
boolean	contains(Item key)	Checks if the set contains the specified key.
protected int	hash(int id)	Returns the hash value of the element with the specified id.
int	id(Item key)	Returns the id of the specified key, or 0 if the key does not exist.
Iterator<Item>	iterator()
protected void	rehash(int newSize)	Rehashes all entries.
String	toString()

Methods inherited from class org.basex.util.hash.ASet

capacity, checkCapacity, checkCapacity, clear, isEmpty, size, toString, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

HashItemSet

public HashItemSet(boolean eq,
                   InputInfo info)

Default constructor.

Parameters:

eq - equality check

info - input info (can be null)

Method Detail

add

public boolean add(Item key)
            throws QueryException

Description copied from interface: ItemSet

Stores the specified key if it has not been stored before.

Specified by:

add in interface ItemSet

Parameters:

key - key to be added

Returns:

true if the key did not exist yet and was stored

Throws:

QueryException - query exception

contains

public boolean contains(Item key)
                 throws QueryException

Checks if the set contains the specified key.

Parameters:

key - key to be looked up

Returns:

result of check

Throws:

QueryException - query exception

id

public int id(Item key)
       throws QueryException

Returns the id of the specified key, or 0 if the key does not exist.

Parameters:

key - key to be looked up

Returns:

id, or 0 if key does not exist

Throws:

QueryException - query exception

hash

protected int hash(int id)

Description copied from class: ASet

Returns the hash value of the element with the specified id.

Specified by:

hash in class ASet

Parameters:

id - id of the element

Returns:

hash value

rehash

protected void rehash(int newSize)

Description copied from class: ASet

Rehashes all entries.

Specified by:

rehash in class ASet

Parameters:

newSize - new hash size

iterator

public Iterator<Item> iterator()

Specified by:

iterator in interface Iterable<Item>

toString

public String toString()

Overrides:

toString in class Object