org.apache.directory.server.core.partition.impl.btree
Class DisjunctionEnumeration

java.lang.Object
  org.apache.directory.server.core.partition.impl.btree.DisjunctionEnumeration

All Implemented Interfaces:

java.util.Enumeration, javax.naming.NamingEnumeration

public class DisjunctionEnumeration
extends java.lang.Object
implements javax.naming.NamingEnumeration

A Cursor of Cursors performing a union on all underlying Cursors resulting in the disjunction of expressions represented by the constituant child Cursors. This cursor prefetches underlying Cursor values so that it can comply with the defined Cursor semantics.

Version:

$Rev: 434579 $

Author:

Apache Directory Project

Constructor Summary

DisjunctionEnumeration(javax.naming.NamingEnumeration[] children)
Creates a DisjunctionEnumeration over a set of child NamingEnumerations.

Method Summary

void	close() Closes all the underlying Cursors and not fail fast.
boolean	hasMore() Tests if a prefetched value exists and a call to advance will hence succeed.
boolean	hasMoreElements()
java.lang.Object	next() Advances this Cursor one position.
java.lang.Object	nextElement()

Methods inherited from class java.lang.Object

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

Constructor Detail

DisjunctionEnumeration

public DisjunctionEnumeration(javax.naming.NamingEnumeration[] children)
                       throws javax.naming.NamingException

Creates a DisjunctionEnumeration over a set of child NamingEnumerations. The returned result is the union of all underlying NamingEnumerations without duplicates.

Parameters:

children - array of child NamingInstances

Throws:

javax.naming.NamingException - if something goes wrong

Method Detail

nextElement

public java.lang.Object nextElement()

Specified by:

nextElement in interface java.util.Enumeration

See Also:

Enumeration.nextElement()

hasMoreElements

public boolean hasMoreElements()

Specified by:

hasMoreElements in interface java.util.Enumeration

See Also:

Enumeration.hasMoreElements()

next

public java.lang.Object next()
                      throws javax.naming.NamingException

Advances this Cursor one position. Duplicates are not returned so if underlying cursors keep returning duplicates the child cursors will be advanced until a unique candidate is found or all child cursors are exhausted.

Specified by:

next in interface javax.naming.NamingEnumeration

Returns:

a candidate element

Throws:

javax.naming.NamingException - if an error occurs

hasMore

public boolean hasMore()

Tests if a prefetched value exists and a call to advance will hence succeed.

Specified by:

hasMore in interface javax.naming.NamingEnumeration

Returns:

true if a call to advance will succeed false otherwise.

close

public void close()
           throws javax.naming.NamingException

Closes all the underlying Cursors and not fail fast. All enumerations will have close attempts made on them.

Specified by:

close in interface javax.naming.NamingEnumeration

Throws:

javax.naming.NamingException - if we cannot close all enumerations