Package org.eclipse.rdf4j.federated.algebra

Class ExclusiveGroup

java.lang.Object

org.eclipse.rdf4j.query.algebra.AbstractQueryModelNode

org.eclipse.rdf4j.federated.algebra.ExclusiveGroup

All Implemented Interfaces:

Serializable, Cloneable, ExclusiveTupleExpr, FedXTupleExpr, FilterTuple, QueryRef, StatementTupleExpr, VariableExpr, GraphPatternGroupable, QueryModelNode, TupleExpr, VariableScopeChange

public class ExclusiveGroup
extends AbstractQueryModelNode
implements StatementTupleExpr, FilterTuple, ExclusiveTupleExpr

Represents a group of ExclusiveTupleExpr that can only produce results at a single endpoint, the StatementSource.

Author:

Andreas Schwarte

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
protected QueryBindingSet	boundFilters
protected FilterValueExpr	filterExpr
protected final Set<String>	freeVars
protected final String	id
protected final List<ExclusiveTupleExpr>	owned
protected Endpoint	ownedEndpoint
protected final StatementSource	owner
protected final QueryInfo	queryInfo

Constructor Summary

Constructors

Constructor	Description
ExclusiveGroup(Collection<? extends ExclusiveTupleExpr> ownedNodes, StatementSource owner, QueryInfo queryInfo)

Method Summary

Modifier and Type	Method	Description
void	addBoundFilter(String varName, Value value)	register a filter that can be directly expressed as a binding, e.g.
void	addFilterExpr(FilterExpr expr)	register a new filter expression.
ExclusiveGroup	clone()	Returns a (deep) clone of this query model node.
CloseableIteration<BindingSet,QueryEvaluationException>	evaluate(BindingSet bindings)	Evaluate this expression using the provided bindings
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.
BindingSet	getBoundFilters()	Returns bound filter bindings, that need to be added as additional bindings to the final result
List<ExclusiveTupleExpr>	getExclusiveExpressions()
FilterValueExpr	getFilterExpr()
int	getFreeVarCount()
List<String>	getFreeVars()
String	getId()
Endpoint	getOwnedEndpoint()
StatementSource	getOwner()
QueryInfo	getQueryInfo()	Retrieve the attached query information of the tuple expression
List<StatementSource>	getStatementSources()
boolean	hasFilter()
boolean	hasFreeVarsFor(BindingSet bindings)	returns true iff this statement has free variables in the presence of the specified binding set
protected void	init()	Initialize free variables
<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.query.algebra.QueryModelNode

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

Field Details

owned

protected final List<ExclusiveTupleExpr> owned

owner

protected final StatementSource owner

freeVars

protected final Set<String> freeVars

id

protected final String id

queryInfo

protected final transient QueryInfo queryInfo

filterExpr

protected FilterValueExpr filterExpr

boundFilters

protected QueryBindingSet boundFilters

ownedEndpoint

protected transient Endpoint ownedEndpoint

Constructor Details

ExclusiveGroup

public ExclusiveGroup(Collection<? extends ExclusiveTupleExpr> ownedNodes,
 StatementSource owner,
 QueryInfo queryInfo)

Method Details

init

protected void init()

Initialize free variables

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

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

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.

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.

clone

public ExclusiveGroup 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.

getOwner

public StatementSource getOwner()

Specified by:

getOwner in interface ExclusiveTupleExpr

Returns:

the owner for this expression

getOwnedEndpoint

public Endpoint getOwnedEndpoint()

getExclusiveExpressions

public List<ExclusiveTupleExpr> getExclusiveExpressions()

getFreeVarCount

public int getFreeVarCount()

Specified by:

getFreeVarCount in interface FedXTupleExpr

Returns:

the number of free (i.e. unbound) variables in this expression

getFreeVars

public List<String> getFreeVars()

Specified by:

getFreeVars in interface FilterTuple

Specified by:

getFreeVars in interface VariableExpr

Returns:

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

getId

public String getId()

Specified by:

getId in interface StatementTupleExpr

Returns:

the id of this expr

getStatementSources

public List<StatementSource> getStatementSources()

Specified by:

getStatementSources in interface StatementTupleExpr

Returns:

a list of sources that are relevant for evaluation of this expression

hasFreeVarsFor

public boolean hasFreeVarsFor(BindingSet bindings)

Description copied from interface: StatementTupleExpr

returns true iff this statement has free variables in the presence of the specified binding set

Specified by:

hasFreeVarsFor in interface StatementTupleExpr

Parameters:

bindings -

Returns:

whether the statement has free vars

evaluate

public CloseableIteration<BindingSet,QueryEvaluationException> evaluate(BindingSet bindings)
                                                                 throws QueryEvaluationException

Description copied from interface: StatementTupleExpr

Evaluate this expression using the provided bindings

Specified by:

evaluate in interface StatementTupleExpr

Parameters:

bindings -

Returns:

the result iteration

Throws:

QueryEvaluationException

addFilterExpr

public void addFilterExpr(FilterExpr expr)

Description copied from interface: FilterTuple

register a new filter expression. If the expr has already a filter registered, the new expression is added to a ConjunctiveFilterExpr.

Specified by:

addFilterExpr in interface FilterTuple

Parameters:

expr -

getFilterExpr

public FilterValueExpr getFilterExpr()

Specified by:

getFilterExpr in interface FilterTuple

Returns:

the currently registered filter expressions, usually of type FilterExpr or ConjunctiveFilterExpr

getBoundFilters

public BindingSet getBoundFilters()

Description copied from interface: FilterTuple

Returns bound filter bindings, that need to be added as additional bindings to the final result

Specified by:

getBoundFilters in interface FilterTuple

Returns:

the bound filters, or null

hasFilter

public boolean hasFilter()

Specified by:

hasFilter in interface FilterTuple

Returns:

true if this expression has a filter to apply

addBoundFilter

public void addBoundFilter(String varName,
 Value value)

Description copied from interface: FilterTuple

register a filter that can be directly expressed as a binding, e.g. SELECT * WHERE { ?s p o . FILTER (?s = X) } is equivalent to SELECT * WHERE { X p o . }

Specified by:

addBoundFilter in interface FilterTuple

Parameters:

varName -

value -

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