de.lmu.ifi.dbs.elki.index.tree
Class BreadthFirstEnumeration<O extends DatabaseObject,N extends Node<N,E>,E extends Entry>

java.lang.Object
  de.lmu.ifi.dbs.elki.index.tree.BreadthFirstEnumeration<O,N,E>

Type Parameters:

O - Object type

N - the type of Node used in the index

E - the type of Entry used in the index

All Implemented Interfaces:

Enumeration<TreeIndexPath<E>>

public class BreadthFirstEnumeration<O extends DatabaseObject,N extends Node<N,E>,E extends Entry>
extends Object
implements Enumeration<TreeIndexPath<E>>

Provides a breadth first enumeration over the nodes of an index structure.

Author:

Elke Achtert

Field Summary

Enumeration<TreeIndexPath<E>>	EMPTY_ENUMERATION Represents an empty enumeration.
private TreeIndex<O,N,E>	index The index storing the nodes.
private Queue<Enumeration<TreeIndexPath<E>>>	queue The queue for the enumeration.

Constructor Summary

BreadthFirstEnumeration(TreeIndex<O,N,E> index, TreeIndexPath<E> rootPath)
Creates a new breadth first enumeration with the specified node as root node.

Method Summary

boolean	hasMoreElements() Tests if this enumeration contains more elements.
TreeIndexPath<E>	nextElement() Returns the next element of this enumeration if this enumeration object has at least one more element to provide.

Methods inherited from class java.lang.Object

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

Field Detail

EMPTY_ENUMERATION

public final Enumeration<TreeIndexPath<E extends Entry>> EMPTY_ENUMERATION

Represents an empty enumeration.

queue

private Queue<Enumeration<TreeIndexPath<E extends Entry>>> queue

The queue for the enumeration.

index

private TreeIndex<O extends DatabaseObject,N extends Node<N,E>,E extends Entry> index

The index storing the nodes.

Constructor Detail

BreadthFirstEnumeration

public BreadthFirstEnumeration(TreeIndex<O,N,E> index,
                               TreeIndexPath<E> rootPath)

Creates a new breadth first enumeration with the specified node as root node.

Parameters:

rootPath - the root entry of the enumeration

index - the index storing the nodes

Method Detail

hasMoreElements

public boolean hasMoreElements()

Tests if this enumeration contains more elements.

Specified by:

hasMoreElements in interface Enumeration<TreeIndexPath<E extends Entry>>

Returns:

true if and only if this enumeration object contains at least one more element to provide; false otherwise.

nextElement

public TreeIndexPath<E> nextElement()

Returns the next element of this enumeration if this enumeration object has at least one more element to provide.

Specified by:

nextElement in interface Enumeration<TreeIndexPath<E extends Entry>>

Returns:

the next element of this enumeration.

Throws:

NoSuchElementException - if no more elements exist.