Package org.eclipse.rdf4j.federated.algebra

Class PassThroughTupleExpr

java.lang.Object

org.eclipse.rdf4j.query.algebra.AbstractQueryModelNode

org.eclipse.rdf4j.federated.algebra.PassThroughTupleExpr

All Implemented Interfaces:

Serializable, Cloneable, FedXTupleExpr, QueryRef, VariableExpr, GraphPatternGroupable, QueryModelNode, TupleExpr, VariableScopeChange

public class PassThroughTupleExpr
extends AbstractQueryModelNode
implements FedXTupleExpr

Marker TupleExpr that is used from FedXTupleQuery.evaluate(TupleQueryResultHandler) to allow for passing through of results to the handler.

Passing through of results to the handler is supported for SingleSourceQuerys, i.e. if the original query is sent as is to the single relevant source. In this case no materialization and in-memory handling through FedX is done, if a TupleQueryResultHandler is supplied.

Author:

Andreas Schwarte

See Also:

• Serialized Form

Constructor Summary

Constructors

Constructor	Description
PassThroughTupleExpr(TupleExpr parsedQuery, TupleQueryResultHandler resultHandler)

Method Summary

Modifier and Type	Method	Description
PassThroughTupleExpr	clone()	Returns a (deep) clone of this query model node.
Set<String>	getAssuredBindingNames()	Gets the names of the bindings that are guaranteed to be present in the results produced by this tuple expression.
Set<String>	getBindingNames()	Gets the names of the bindings that are, or can be, returned by this tuple expression when it is evaluated.
TupleExpr	getExpr()
List<String>	getFreeVars()
QueryInfo	getQueryInfo()	Retrieve the attached query information of the tuple expression
TupleQueryResultHandler	getResultHandler()
boolean	isPassedThrough()
void	setPassedThrough(boolean flag)
<X extends Exception> void	visit(QueryModelVisitor<X> visitor)	Visits this node.
<X extends Exception> void	visitChildren(QueryModelVisitor<X> visitor)	Dummy implementation of QueryModelNode.visitChildren(org.eclipse.rdf4j.query.algebra.QueryModelVisitor<X>) that does nothing.

Methods inherited from class org.eclipse.rdf4j.query.algebra.AbstractQueryModelNode

getCardinality, getCostEstimate, getParentNode, getResultSizeActual, getResultSizeEstimate, getSignature, getTotalTimeNanosActual, isCardinalitySet, isGraphPatternGroup, isVariableScopeChange, nullEquals, replaceChildNode, replaceNodeInList, replaceWith, resetCardinality, setCardinality, setCostEstimate, setGraphPatternGroup, setParentNode, setResultSizeActual, setResultSizeEstimate, setTotalTimeNanosActual, setVariableScopeChange, shouldCacheCardinality, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.eclipse.rdf4j.federated.algebra.FedXTupleExpr

getFreeVarCount

Methods inherited from interface org.eclipse.rdf4j.query.algebra.QueryModelNode

equals, getCostEstimate, getParentNode, getResultSizeActual, getResultSizeEstimate, getSignature, getTotalTimeNanosActual, replaceChildNode, replaceWith, setCostEstimate, setParentNode, setResultSizeActual, setResultSizeEstimate, setTotalTimeNanosActual, toString

Constructor Details

PassThroughTupleExpr

public PassThroughTupleExpr(TupleExpr parsedQuery,
 TupleQueryResultHandler resultHandler)

Method Details

visitChildren

public <X extends Exception> void visitChildren(QueryModelVisitor<X> visitor)
                                         throws X

Description copied from class: AbstractQueryModelNode

Dummy implementation of QueryModelNode.visitChildren(org.eclipse.rdf4j.query.algebra.QueryModelVisitor<X>) that does nothing. Subclasses should override this method when they have child nodes.

Specified by:

visitChildren in interface QueryModelNode

Overrides:

visitChildren in class AbstractQueryModelNode

Throws:

X

getResultHandler

public TupleQueryResultHandler getResultHandler()

getExpr

public TupleExpr getExpr()

isPassedThrough

public boolean isPassedThrough()

Returns:

if the query result has already been passed through to the supplied TupleQueryResultHandler

setPassedThrough

public void setPassedThrough(boolean flag)

getBindingNames

public Set<String> getBindingNames()

Description copied from interface: TupleExpr

Gets the names of the bindings that are, or can be, returned by this tuple expression when it is evaluated.

Specified by:

getBindingNames in interface TupleExpr

Returns:

A set of binding names.

getAssuredBindingNames

public Set<String> getAssuredBindingNames()

Description copied from interface: TupleExpr

Gets the names of the bindings that are guaranteed to be present in the results produced by this tuple expression.

Specified by:

getAssuredBindingNames in interface TupleExpr

Returns:

A set of binding names.

clone

public PassThroughTupleExpr clone()

Description copied from interface: QueryModelNode

Returns a (deep) clone of this query model node. This method recursively clones the entire node tree, starting from this nodes.

Specified by:

clone in interface QueryModelNode

Specified by:

clone in interface TupleExpr

Overrides:

clone in class AbstractQueryModelNode

Returns:

A deep clone of this query model node.

visit

public <X extends Exception> void visit(QueryModelVisitor<X> visitor)
                                 throws X

Description copied from interface: QueryModelNode

Visits this node. The node reports itself to the visitor with the proper runtime type.

Specified by:

visit in interface QueryModelNode

Throws:

X

getFreeVars

public List<String> getFreeVars()

Specified by:

getFreeVars in interface VariableExpr

Returns:

a list of free (i.e. unbound) variables in this expression

getQueryInfo

public QueryInfo getQueryInfo()

Description copied from interface: QueryRef

Retrieve the attached query information of the tuple expression

Specified by:

getQueryInfo in interface QueryRef

Returns:

the QueryInfo