org.apache.directory.server.xdbm.search.cursor

Class AndCursor<V>

java.lang.Object

org.apache.directory.api.ldap.model.cursor.AbstractCursor<IndexEntry<V,java.lang.String>>

org.apache.directory.server.xdbm.AbstractIndexCursor<V>

org.apache.directory.server.xdbm.search.cursor.AndCursor<V>

All Implemented Interfaces:

java.lang.Iterable<IndexEntry<V,java.lang.String>>, org.apache.directory.api.ldap.model.cursor.Cursor<IndexEntry<V,java.lang.String>>

public class AndCursor<V>
extends AbstractIndexCursor<V>

A Cursor returning candidates satisfying a logical conjunction expression.

Field Summary

Fields

Modifier and Type	Field and Description
private java.util.List<Evaluator<? extends org.apache.directory.api.ldap.model.filter.ExprNode>>	evaluators The evaluators used for the members of the And filter
private static boolean	IS_DEBUG Speedup for logs
private static org.slf4j.Logger	LOG_CURSOR A dedicated log for cursors
private static java.lang.String	UNSUPPORTED_MSG The message for unsupported operations
private org.apache.directory.api.ldap.model.cursor.Cursor<IndexEntry<V,java.lang.String>>	wrapped

Constructor Summary

Constructors

Constructor and Description
AndCursor(org.apache.directory.api.ldap.model.cursor.Cursor<IndexEntry<V,java.lang.String>> wrapped, java.util.List<Evaluator<? extends org.apache.directory.api.ldap.model.filter.ExprNode>> evaluators) Creates an instance of a AndCursor.

Method Summary

Modifier and Type	Method and Description
void	afterLast()
void	beforeFirst()
void	close()
void	close(java.lang.Exception cause)
private java.lang.String	dumpEvaluators(java.lang.String tabs) Dumps the evaluators
boolean	first()
IndexEntry<V,java.lang.String>	get()
protected java.lang.String	getUnsupportedMessage() Gets the message to return for operations that are not supported
boolean	last()
private boolean	matches(IndexEntry<V,java.lang.String> indexEntry) Checks if the entry is a valid candidate by using the evaluators.
boolean	next()
private java.util.List<Evaluator<? extends org.apache.directory.api.ldap.model.filter.ExprNode>>	optimize(java.util.List<Evaluator<? extends org.apache.directory.api.ldap.model.filter.ExprNode>> unoptimized) Takes a set of Evaluators and copies then sorts them in a new list with increasing scan counts on their expression nodes.
boolean	previous()
java.lang.String	toString()
java.lang.String	toString(java.lang.String tabs)

Methods inherited from class org.apache.directory.server.xdbm.AbstractIndexCursor

after, available, before, setAvailable

Methods inherited from class org.apache.directory.api.ldap.model.cursor.AbstractCursor

checkNotClosed, isAfterLast, isBeforeFirst, isClosed, isFirst, isLast, iterator, setClosureMonitor

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

Field Detail

LOG_CURSOR

private static final org.slf4j.Logger LOG_CURSOR

A dedicated log for cursors

IS_DEBUG

private static final boolean IS_DEBUG

Speedup for logs

UNSUPPORTED_MSG

private static final java.lang.String UNSUPPORTED_MSG

The message for unsupported operations

wrapped

private final org.apache.directory.api.ldap.model.cursor.Cursor<IndexEntry<V,java.lang.String>> wrapped

evaluators

private final java.util.List<Evaluator<? extends org.apache.directory.api.ldap.model.filter.ExprNode>> evaluators

The evaluators used for the members of the And filter

Constructor Detail

AndCursor

public AndCursor(org.apache.directory.api.ldap.model.cursor.Cursor<IndexEntry<V,java.lang.String>> wrapped,
                 java.util.List<Evaluator<? extends org.apache.directory.api.ldap.model.filter.ExprNode>> evaluators)

Creates an instance of a AndCursor. It wraps an index cursor and the list of evaluators associated with all the elements connected by the And.

Parameters:

wrapped - The encapsulated IndexCursor

evaluators - The list of evaluators associated wth the elements

Method Detail

getUnsupportedMessage

protected java.lang.String getUnsupportedMessage()

Gets the message to return for operations that are not supported

Specified by:

getUnsupportedMessage in class AbstractIndexCursor<V>

Returns:

The Unsupported message

beforeFirst

public void beforeFirst()
                 throws org.apache.directory.api.ldap.model.exception.LdapException,
                        org.apache.directory.api.ldap.model.cursor.CursorException

Throws:

org.apache.directory.api.ldap.model.exception.LdapException

org.apache.directory.api.ldap.model.cursor.CursorException

afterLast

public void afterLast()
               throws org.apache.directory.api.ldap.model.exception.LdapException,
                      org.apache.directory.api.ldap.model.cursor.CursorException

Throws:

org.apache.directory.api.ldap.model.exception.LdapException

org.apache.directory.api.ldap.model.cursor.CursorException

first

public boolean first()
              throws org.apache.directory.api.ldap.model.exception.LdapException,
                     org.apache.directory.api.ldap.model.cursor.CursorException

Throws:

org.apache.directory.api.ldap.model.exception.LdapException

org.apache.directory.api.ldap.model.cursor.CursorException

last

public boolean last()
             throws org.apache.directory.api.ldap.model.exception.LdapException,
                    org.apache.directory.api.ldap.model.cursor.CursorException

Throws:

org.apache.directory.api.ldap.model.exception.LdapException

org.apache.directory.api.ldap.model.cursor.CursorException

previous

public boolean previous()
                 throws org.apache.directory.api.ldap.model.exception.LdapException,
                        org.apache.directory.api.ldap.model.cursor.CursorException

Throws:

org.apache.directory.api.ldap.model.exception.LdapException

org.apache.directory.api.ldap.model.cursor.CursorException

next

public boolean next()
             throws org.apache.directory.api.ldap.model.exception.LdapException,
                    org.apache.directory.api.ldap.model.cursor.CursorException

Throws:

org.apache.directory.api.ldap.model.exception.LdapException

org.apache.directory.api.ldap.model.cursor.CursorException

get

public IndexEntry<V,java.lang.String> get()
                                   throws org.apache.directory.api.ldap.model.cursor.CursorException

Throws:

org.apache.directory.api.ldap.model.cursor.CursorException

close

public void close()

Specified by:

close in interface org.apache.directory.api.ldap.model.cursor.Cursor<IndexEntry<V,java.lang.String>>

Overrides:

close in class org.apache.directory.api.ldap.model.cursor.AbstractCursor<IndexEntry<V,java.lang.String>>

close

public void close(java.lang.Exception cause)

Specified by:

close in interface org.apache.directory.api.ldap.model.cursor.Cursor<IndexEntry<V,java.lang.String>>

Overrides:

close in class org.apache.directory.api.ldap.model.cursor.AbstractCursor<IndexEntry<V,java.lang.String>>

optimize

private java.util.List<Evaluator<? extends org.apache.directory.api.ldap.model.filter.ExprNode>> optimize(java.util.List<Evaluator<? extends org.apache.directory.api.ldap.model.filter.ExprNode>> unoptimized)

Takes a set of Evaluators and copies then sorts them in a new list with increasing scan counts on their expression nodes. This is done to have the Evaluators with the least scan count which have the highest probability of rejecting a candidate first. That will increase the chance of shorting the checks on evaluators early so extra lookups and comparisons are avoided.

Parameters:

unoptimized - the unoptimized list of Evaluators

Returns:

optimized Evaluator list with increasing scan count ordering

matches

private boolean matches(IndexEntry<V,java.lang.String> indexEntry)
                 throws org.apache.directory.api.ldap.model.exception.LdapException

Checks if the entry is a valid candidate by using the evaluators.

Throws:

org.apache.directory.api.ldap.model.exception.LdapException

dumpEvaluators

private java.lang.String dumpEvaluators(java.lang.String tabs)

Dumps the evaluators

toString

public java.lang.String toString(java.lang.String tabs)

Specified by:

toString in interface org.apache.directory.api.ldap.model.cursor.Cursor<IndexEntry<V,java.lang.String>>

Overrides:

toString in class org.apache.directory.api.ldap.model.cursor.AbstractCursor<IndexEntry<V,java.lang.String>>

See Also:

Object.toString()

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

See Also:

Object.toString()