Class PathIteration

java.lang.Object

org.eclipse.rdf4j.common.iteration.AbstractCloseableIteration<BindingSet, QueryEvaluationException>

org.eclipse.rdf4j.common.iteration.LookAheadIteration<BindingSet, QueryEvaluationException>

org.eclipse.rdf4j.query.algebra.evaluation.iterator.PathIteration

All Implemented Interfaces:

AutoCloseable, CloseableIteration<BindingSet, QueryEvaluationException>, Iteration<BindingSet, QueryEvaluationException>

public class PathIteration
extends LookAheadIteration<BindingSet, QueryEvaluationException>

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected static class	PathIteration.ValuePair
(package private) class	PathIteration.VarReplacer

Field Summary

Fields

Modifier and Type	Field	Description
private final BindingSet	bindings
private final Var	contextVar
private CloseableIteration<BindingSet, QueryEvaluationException>	currentIter
private long	currentLength
private PathIteration.ValuePair	currentVp
private final Var	endVar
private final boolean	endVarFixed
private static final String	JOINVAR_PREFIX
private final Set<String>	namedIntermediateJoins
private final TupleExpr	pathExpression
private final Set<PathIteration.ValuePair>	reportedValues
private final StatementPattern.Scope	scope
private final Var	startVar
private final boolean	startVarFixed
private final EvaluationStrategy	strategy
private final Set<PathIteration.ValuePair>	unreportedValues
private final Queue<PathIteration.ValuePair>	valueQueue

Constructor Summary

Constructors

Constructor	Description
PathIteration(EvaluationStrategy strategy, StatementPattern.Scope scope, Var startVar, TupleExpr pathExpression, Var endVar, Var contextVar, long minLength, BindingSet bindings)

Method Summary

Modifier and Type	Method	Description
protected boolean	add(Set<PathIteration.ValuePair> valueSet, PathIteration.ValuePair vp)
private void	addBinding(MutableBindingSet bs, String name, Value value)
protected boolean	addToQueue(Queue<PathIteration.ValuePair> valueQueue2, PathIteration.ValuePair vp)
Var	createAnonVar(String varName)
private Var	createAnonVar(String varName, Value v, boolean anonymous)
private void	createIteration()
protected BindingSet	getNextElement()	Gets the next element.
private Value	getVarValue(Var var, boolean fixedValue, BindingSet bindingSet)
protected void	handleClose()	Called by AbstractCloseableIteration.close() when it is called for the first time.
private boolean	isCyclicPath(PathIteration.ValuePair vp)
protected boolean	isUnbound(Var var, BindingSet bindings)
private BindingSet	removeIntermediateJoinVars(QueryBindingSet nextElement)
private PathIteration.ValuePair	valuePairFromStartAndEnd(MutableBindingSet nextElement)

Methods inherited from class LookAheadIteration

hasNext, next, remove

Methods inherited from class AbstractCloseableIteration

close, isClosed

Methods inherited from class Object

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

Methods inherited from interface CloseableIteration

stream

Field Details

strategy

private final EvaluationStrategy strategy

currentLength

private long currentLength

currentIter

private CloseableIteration<BindingSet, QueryEvaluationException> currentIter

bindings

private final BindingSet bindings

scope

private final StatementPattern.Scope scope

startVar

private final Var startVar

endVar

private final Var endVar

startVarFixed

private final boolean startVarFixed

endVarFixed

private final boolean endVarFixed

valueQueue

private final Queue<PathIteration.ValuePair> valueQueue

reportedValues

private final Set<PathIteration.ValuePair> reportedValues

unreportedValues

private final Set<PathIteration.ValuePair> unreportedValues

pathExpression

private final TupleExpr pathExpression

contextVar

private final Var contextVar

currentVp

private PathIteration.ValuePair currentVp

JOINVAR_PREFIX

private static final String JOINVAR_PREFIX

See Also:

• Constant Field Values

namedIntermediateJoins

private final Set<String> namedIntermediateJoins

Constructor Details

PathIteration

public PathIteration(EvaluationStrategy strategy,
 StatementPattern.Scope scope,
 Var startVar,
 TupleExpr pathExpression,
 Var endVar,
 Var contextVar,
 long minLength,
 BindingSet bindings)
              throws QueryEvaluationException

Throws:

QueryEvaluationException

Method Details

getNextElement

protected BindingSet getNextElement()
                             throws QueryEvaluationException

Description copied from class: LookAheadIteration

Gets the next element. Subclasses should implement this method so that it returns the next element.

Specified by:

getNextElement in class LookAheadIteration<BindingSet, QueryEvaluationException>

Returns:

The next element, or null if no more elements are available.

Throws:

QueryEvaluationException

removeIntermediateJoinVars

private BindingSet removeIntermediateJoinVars(QueryBindingSet nextElement)

valuePairFromStartAndEnd

private PathIteration.ValuePair valuePairFromStartAndEnd(MutableBindingSet nextElement)

addBinding

private void addBinding(MutableBindingSet bs,
 String name,
 Value value)

handleClose

protected void handleClose()
                    throws QueryEvaluationException

Description copied from class: AbstractCloseableIteration

Called by AbstractCloseableIteration.close() when it is called for the first time. This method is only called once on each iteration. By default, this method does nothing.

Overrides:

handleClose in class LookAheadIteration<BindingSet, QueryEvaluationException>

Throws:

QueryEvaluationException

addToQueue

protected boolean addToQueue(Queue<PathIteration.ValuePair> valueQueue2,
 PathIteration.ValuePair vp)
                      throws QueryEvaluationException

Parameters:

valueQueue2 -

vp -

Throws:

QueryEvaluationException

add

protected boolean add(Set<PathIteration.ValuePair> valueSet,
 PathIteration.ValuePair vp)
               throws QueryEvaluationException

Parameters:

valueSet -

vp -

Throws:

QueryEvaluationException

getVarValue

private Value getVarValue(Var var,
 boolean fixedValue,
 BindingSet bindingSet)

isCyclicPath

private boolean isCyclicPath(PathIteration.ValuePair vp)

createIteration

private void createIteration()
                      throws QueryEvaluationException

Throws:

QueryEvaluationException

isUnbound

protected boolean isUnbound(Var var,
 BindingSet bindings)

createAnonVar

private Var createAnonVar(String varName,
 Value v,
 boolean anonymous)

createAnonVar

public Var createAnonVar(String varName)