Class OrderComparator

java.lang.Object

org.eclipse.rdf4j.query.algebra.evaluation.util.OrderComparator

All Implemented Interfaces:

Comparator<BindingSet>

public class OrderComparator
extends Object
implements Comparator<BindingSet>

A Comparator on BindingSets that imposes a total ordering by examining supplied Order elements (i.e. the elements of an ORDER BY clause), falling back on a custom predictable ordering for BindingSet elements if no ordering is established on the basis of the Order elements.

Field Summary

Fields

Modifier and Type	Field	Description
private final Comparator<BindingSet>	bindingContentsComparator
private final ValueComparator	cmp
private static final org.slf4j.Logger	logger

Constructor Summary

Constructors

Constructor	Description
OrderComparator(EvaluationStrategy strategy, Order order, ValueComparator cmp, QueryEvaluationContext context)

Method Summary

Modifier and Type	Method	Description
int	compare(BindingSet o1, BindingSet o2)
private static List<String>	getSortedBindingNames(Set<String> bindingNames)
private Comparator<BindingSet>	precompileComparator(EvaluationStrategy strategy, Order order, QueryEvaluationContext context)
private boolean	sortedEquals(List<String> o1bindingNamesOrdered, List<String> o2bindingNamesOrdered)

Methods inherited from class Object

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

Methods inherited from interface Comparator

equals, reversed, thenComparing, thenComparing, thenComparing, thenComparingDouble, thenComparingInt, thenComparingLong

Field Details

logger

private static final org.slf4j.Logger logger

cmp

private final ValueComparator cmp

bindingContentsComparator

private final Comparator<BindingSet> bindingContentsComparator

Constructor Details

OrderComparator

public OrderComparator(EvaluationStrategy strategy,
 Order order,
 ValueComparator cmp,
 QueryEvaluationContext context)

Method Details

precompileComparator

private Comparator<BindingSet> precompileComparator(EvaluationStrategy strategy,
 Order order,
 QueryEvaluationContext context)

compare

public int compare(BindingSet o1,
 BindingSet o2)

Specified by:

compare in interface Comparator<BindingSet>

sortedEquals

private boolean sortedEquals(List<String> o1bindingNamesOrdered,
 List<String> o2bindingNamesOrdered)

getSortedBindingNames

private static List<String> getSortedBindingNames(Set<String> bindingNames)