ServiceJoinIterator (Eclipse RDF4J 4.2.4)

java.lang.Object
- org.eclipse.rdf4j.common.iteration.AbstractCloseableIteration<E,X>
- - org.eclipse.rdf4j.common.iteration.LookAheadIteration<T,QueryEvaluationException>
  - - org.eclipse.rdf4j.repository.sparql.federation.JoinExecutorBase<T>
    - - org.eclipse.rdf4j.query.algebra.evaluation.federation.JoinExecutorBase<BindingSet>
      - org.eclipse.rdf4j.query.algebra.evaluation.federation.ServiceJoinIterator

All Implemented Interfaces:

AutoCloseable, CloseableIteration<BindingSet,QueryEvaluationException>, Iteration<BindingSet,QueryEvaluationException>
```
public class ServiceJoinIterator
extends JoinExecutorBase<BindingSet>
```
Iterator for efficient SERVICE evaluation (vectored). SERVICE is the right handside argument of this join.

Author:

Andreas Schwarte

Field Summary

Fields
Modifier and Type Field Description

protected Service service

protected EvaluationStrategy strategy
- Fields inherited from class org.eclipse.rdf4j.repository.sparql.federation.JoinExecutorBase
  bindings, closed, finished, leftIter, NEXT_JOIN_ID, rightArg, rightIter, rightQueue

Constructor Summary

Constructors
Constructor	Description
`ServiceJoinIterator(CloseableIteration<BindingSet,QueryEvaluationException> leftIter, Service service, BindingSet bindings, EvaluationStrategy strategy)`	Construct a service join iteration to use vectored evaluation.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type Method Description

protected void handleBindings()
Implementations must implement this method to handle bindings.
- Methods inherited from class org.eclipse.rdf4j.repository.sparql.federation.JoinExecutorBase
  addResult, done, getNextElement, handleClose, isFinished, run, toss
- Methods inherited from class org.eclipse.rdf4j.common.iteration.LookAheadIteration
  hasNext, next, remove
- Methods inherited from class org.eclipse.rdf4j.common.iteration.AbstractCloseableIteration
  close, isClosed
- Methods inherited from class java.lang.Object
  clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
- Methods inherited from interface org.eclipse.rdf4j.common.iteration.CloseableIteration
  stream

- Field Detail
  - service
```
protected Service service
```
  - strategy
```
protected EvaluationStrategy strategy
```
- Constructor Detail
  - ServiceJoinIterator
```
public ServiceJoinIterator(CloseableIteration<BindingSet,QueryEvaluationException> leftIter,
                           Service service,
                           BindingSet bindings,
                           EvaluationStrategy strategy)
                    throws QueryEvaluationException
```
    Construct a service join iteration to use vectored evaluation. The constructor automatically starts evaluation.
    
    Parameters:
    
    leftIter -
    
    service -
    
    bindings -
    
    strategy -
    
    Throws:
    
    QueryEvaluationException
- Method Detail
  - handleBindings
```
protected void handleBindings()
                       throws Exception
```
    Description copied from class: JoinExecutorBase
    
    Implementations must implement this method to handle bindings. Use the following as a template while (!closed && leftIter.hasNext()) { // your code } and add results to rightQueue. Note that addResult() is implemented synchronized and thus thread safe. In case you can guarantee sequential access, it is also possible to directly access rightQueue
    
    Specified by:
    
    handleBindings in class JoinExecutorBase<BindingSet>
    
    Throws:
    
    Exception