org.openanzo.model.impl.query
Class BasicGraphSolutionGenerator

java.lang.Object
  org.openanzo.model.impl.query.CoreSolutionGenerator
      org.openanzo.model.impl.query.BasicGraphSolutionGenerator

All Implemented Interfaces:

SolutionGenerator

public class BasicGraphSolutionGenerator
extends CoreSolutionGenerator

BasicGraphSolutionGenerator solves only TriplePatternNode patterns using NamedGraphs retrieved from the EngineConfig's dataset.

Author:

Matthew Roy ( mroy@cambridgesemantics.com )

Constructor Summary

BasicGraphSolutionGenerator(IDataset iDataset)
Create new BasicGraphSolutionGenerator in order to solve TriplePatternNode patterns within query

Method Summary

SolutionSet	generateSolutions(TreeNode node, IRIReference namedGraph, Variable namedGraphVariable, SolutionSet requiredBindings)
void	setRDFDataset(RDFDataset<?> dataset)

Methods inherited from class org.openanzo.model.impl.query.CoreSolutionGenerator

canBindGraphVariables, canHandleSimultaneousRequests, cleanup, getQueryExecutionPlan, getQueryExecutionServices, getQueryInformation, getRDFDataset, initialize, setIncludeInferredTriples, setOntology, setQueryExecutionPlan, setQueryExecutionServices, setQueryInformation, sortedSolutions, usesRequiredBindings, willHandleFilters

Methods inherited from class java.lang.Object

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

Constructor Detail

BasicGraphSolutionGenerator

public BasicGraphSolutionGenerator(IDataset iDataset)

Create new BasicGraphSolutionGenerator in order to solve TriplePatternNode patterns within query

Parameters:

iDataset - Source of default and named graphs

Method Detail

generateSolutions

public SolutionSet generateSolutions(TreeNode node,
                                     IRIReference namedGraph,
                                     Variable namedGraphVariable,
                                     SolutionSet requiredBindings)
                              throws CannotGenerateSolutionsException

Parameters:

node - The node in the tree for which bindings are desired.

namedGraph - If not null, the solutions should be generated by matching against this graph from the named graph part of the RDF dataSet. Otherwise, the solutions should be generated from the default graph. (i.e., if not null, treat this graph as the default graph)

namedGraphVariable - If not null and this SolutionGenerator returns true for canBindGraphVariables(), then this is the variable that should be bound to the named graph IRI from which solutions are found.

requiredBindings - Known bindings at this point in the AST. Every returned solution should be a superset of one solution from the required bindings. (That is, unbound variables can be bound, but all bound variables must remain bound to the same value.) Note that Glitter enforces this constraint when combining pattern solutions. In general, if generateSolutions returns a value (null or otherwise), then the SolutionGenerator will not be called again for any descendants of node. If an exception is thrown, then generateSolution may be called for descendant (simpler) nodes.

Returns:

A list of bindings (for variables and blank nodes) that satisfy the given tree node, or null if this pattern doesn't match.

Throws:

CannotGenerateSolutionsException - if the SolutionGenerator does not wish to handle this tree node.

setRDFDataset

public void setRDFDataset(RDFDataset<?> dataset)

Specified by:

setRDFDataset in interface SolutionGenerator

Overrides:

setRDFDataset in class CoreSolutionGenerator

Parameters:

dataset - The RDFDataset against which the query is being executed.