Package org.eclipse.rdf4j.federated.algebra

Class FedXStatementPattern

java.lang.Object

org.eclipse.rdf4j.query.algebra.AbstractQueryModelNode

org.eclipse.rdf4j.query.algebra.StatementPattern

org.eclipse.rdf4j.federated.algebra.FedXStatementPattern

All Implemented Interfaces:

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

Direct Known Subclasses:

ExclusiveStatement, StatementSourcePattern

public abstract class FedXStatementPattern
extends StatementPattern
implements StatementTupleExpr, FilterTuple, BoundJoinTupleExpr

Base class providing all common functionality for FedX StatementPatterns

Author:

Andreas Schwarte

See Also:

• StatementSourcePattern
• ExclusiveStatement
• Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class org.eclipse.rdf4j.query.algebra.StatementPattern

StatementPattern.Scope

Field Summary

Fields

Modifier and Type	Field	Description
protected QueryBindingSet	boundFilters
protected FilterValueExpr	filterExpr
protected final List<String>	freeVars
protected final String	id
protected final QueryInfo	queryInfo
protected final List<StatementSource>	statementSources
protected long	upperLimit

Fields inherited from class org.eclipse.rdf4j.query.algebra.StatementPattern

CARDINALITY_NOT_SET

Constructor Summary

Constructors

Constructor	Description
FedXStatementPattern(StatementPattern node, 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.
BindingSet	getBoundFilters()	Returns bound filter bindings, that need to be added as additional bindings to the final result
FilterValueExpr	getFilterExpr()
int	getFreeVarCount()
List<String>	getFreeVars()
String	getId()
QueryInfo	getQueryInfo()	Retrieve the attached query information of the tuple expression
int	getSourceCount()
List<StatementSource>	getStatementSources()
long	getUpperLimit()
boolean	hasFilter()
boolean	hasFreeVarsFor(BindingSet bindings)	returns true iff this statement has free variables in the presence of the specified binding set
protected void	initFreeVars()
void	setUpperLimit(long upperLimit)	Set the upper limit for this statement expression (i.e.
<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.StatementPattern

clone, equals, getAssuredBindingNames, getBindingNames, getContextVar, getObjectVar, getPredicateVar, getScope, getSignature, getSubjectVar, getVarList, getVars, hashCode, replaceChildNode, setContextVar, setObjectVar, setPredicateVar, setScope, setSubjectVar, shouldCacheCardinality

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

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

Methods inherited from class java.lang.Object

finalize, getClass, 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

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

evaluate

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

clone, getAssuredBindingNames, getBindingNames

Field Details

statementSources

protected final List<StatementSource> statementSources

id

protected final String id

queryInfo

protected final QueryInfo queryInfo

freeVars

protected final List<String> freeVars

filterExpr

protected FilterValueExpr filterExpr

boundFilters

protected QueryBindingSet boundFilters

upperLimit

protected long upperLimit

Constructor Details

FedXStatementPattern

public FedXStatementPattern(StatementPattern node,
 QueryInfo queryInfo)

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 StatementPattern

Throws:

X extends Exception

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

Overrides:

visit in class StatementPattern

Throws:

X extends Exception

initFreeVars

protected void initFreeVars()

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

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

getId

public String getId()

Specified by:

getId in interface StatementTupleExpr

Returns:

the id of this expr

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

Returns:

whether the statement has free vars

getStatementSources

public List<StatementSource> getStatementSources()

Specified by:

getStatementSources in interface StatementTupleExpr

Returns:

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

getSourceCount

public int getSourceCount()

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

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

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

setUpperLimit

public void setUpperLimit(long upperLimit)

Set the upper limit for this statement expression (i.e. applied in the evaluation to individual subqueries of this expr)

Parameters:

upperLimit - the upper limit, a negative number means unlimited

getUpperLimit

public long getUpperLimit()

Returns:

the upper limit or a negative number (meaning no LIMIT)