Examples with ProjectionElemList org.openrdf.query.algebra.ProjectionElemList used on opensource projects

Example 11 with ProjectionElemList

use of org.openrdf.query.algebra.ProjectionElemList in project incubator-rya by apache.

the class AggregationPipelineQueryNode method project.

/**
 * Add a SPARQL projection or multi-projection operation to the pipeline.
 * The number of documents produced by the pipeline after this operation
 * will be the number of documents entering this stage (the number of
 * intermediate results) multiplied by the number of
 * {@link ProjectionElemList}s supplied here. Empty projections are
 * unsupported; if one or more projections given binds zero variables, then
 * the pipeline will be unchanged and the method will return false.
 * @param projections One or more projections, i.e. mappings from the result
 *  at this stage of the query into a set of variables.
 * @return true if the projection(s) were added to the pipeline.
 */
public boolean project(Iterable<ProjectionElemList> projections) {
    if (projections == null || !projections.iterator().hasNext()) {
        return false;
    }
    List<Bson> projectOpts = new LinkedList<>();
    Set<String> bindingNamesUnion = new HashSet<>();
    Set<String> bindingNamesIntersection = null;
    for (ProjectionElemList projection : projections) {
        if (projection.getElements().isEmpty()) {
            // Empty projections are unsupported -- fail when seen
            return false;
        }
        Document valueDoc = new Document();
        Document hashDoc = new Document();
        Document typeDoc = new Document();
        Set<String> projectionBindingNames = new HashSet<>();
        for (ProjectionElem elem : projection.getElements()) {
            String to = elem.getTargetName();
            // If the 'to' name is invalid, replace it internally
            if (!isValidFieldName(to)) {
                to = replace(to);
            }
            String from = elem.getSourceName();
            // If the 'from' name is invalid, use the internal substitute
            if (varToOriginalName.containsValue(from)) {
                from = varToOriginalName.inverse().get(from);
            }
            projectionBindingNames.add(to);
            if (to.equals(from)) {
                valueDoc.append(to, 1);
                hashDoc.append(to, 1);
                typeDoc.append(to, 1);
            } else {
                valueDoc.append(to, valueFieldExpr(from));
                hashDoc.append(to, hashFieldExpr(from));
                typeDoc.append(to, typeFieldExpr(from));
            }
        }
        bindingNamesUnion.addAll(projectionBindingNames);
        if (bindingNamesIntersection == null) {
            bindingNamesIntersection = new HashSet<>(projectionBindingNames);
        } else {
            bindingNamesIntersection.retainAll(projectionBindingNames);
        }
        projectOpts.add(new Document().append(VALUES, valueDoc).append(HASHES, hashDoc).append(TYPES, typeDoc).append(LEVEL, "$" + LEVEL).append(TIMESTAMP, "$" + TIMESTAMP));
    }
    if (projectOpts.size() == 1) {
        pipeline.add(Aggregates.project(projectOpts.get(0)));
    } else {
        String listKey = "PROJECTIONS";
        Bson projectIndividual = Projections.fields(Projections.computed(VALUES, "$" + listKey + "." + VALUES), Projections.computed(HASHES, "$" + listKey + "." + HASHES), Projections.computed(TYPES, "$" + listKey + "." + TYPES), Projections.include(LEVEL), Projections.include(TIMESTAMP));
        pipeline.add(Aggregates.project(Projections.computed(listKey, projectOpts)));
        pipeline.add(Aggregates.unwind("$" + listKey));
        pipeline.add(Aggregates.project(projectIndividual));
    }
    assuredBindingNames.clear();
    bindingNames.clear();
    assuredBindingNames.addAll(bindingNamesIntersection);
    bindingNames.addAll(bindingNamesUnion);
    return true;
}

Example 12 with ProjectionElemList

use of org.openrdf.query.algebra.ProjectionElemList in project incubator-rya by apache.

the class ConstructConsequentVisitorTest method testConcreteSP.

@Test
public void testConcreteSP() {
    Extension extension = new Extension(new SingletonSet(), new ExtensionElem(new ValueConstant(FOAF.PERSON), "x"), new ExtensionElem(new ValueConstant(RDF.TYPE), "y"), new ExtensionElem(new ValueConstant(OWL.CLASS), "z"));
    Projection projection = new Projection(extension, new ProjectionElemList(new ProjectionElem("x", "subject"), new ProjectionElem("y", "predicate"), new ProjectionElem("z", "object")));
    ConstructConsequentVisitor visitor = new ConstructConsequentVisitor();
    projection.visit(visitor);
    Set<StatementPattern> expected = Sets.newHashSet(new StatementPattern(s(FOAF.PERSON), p(RDF.TYPE), o(OWL.CLASS)));
    Assert.assertEquals(expected, visitor.getConsequents());
}

Example 13 with ProjectionElemList

use of org.openrdf.query.algebra.ProjectionElemList in project incubator-rya by apache.

the class ConstructConsequentVisitorTest method testMissingVariables.

@Test
public void testMissingVariables() {
    Extension extension = new Extension(new SingletonSet(), new ExtensionElem(new ValueConstant(FOAF.PERSON), "x"), new ExtensionElem(new ValueConstant(RDF.TYPE), "y"));
    Projection projection = new Projection(extension, new ProjectionElemList(new ProjectionElem("x", "s"), new ProjectionElem("y", "predicate"), new ProjectionElem("z", "object")));
    ConstructConsequentVisitor visitor = new ConstructConsequentVisitor();
    projection.visit(visitor);
    Set<StatementPattern> expected = Sets.newHashSet(new StatementPattern(s(null), p(RDF.TYPE), o(null)));
    Assert.assertEquals(expected, visitor.getConsequents());
}

Example 14 with ProjectionElemList

use of org.openrdf.query.algebra.ProjectionElemList in project incubator-rya by apache.

the class SparqlFluoQueryBuilder method getConstructGraphVarOrder.

private static VariableOrder getConstructGraphVarOrder(final Reduced node) {
    // get child node
    final QueryModelNode child = node.getArg();
    Preconditions.checkArgument(child instanceof Projection || child instanceof MultiProjection);
    final UnaryTupleOperator unary = (UnaryTupleOperator) child;
    // get ProjectionElemList to build ConstructGraph
    final List<ProjectionElemList> projections = new ArrayList<>();
    if (unary instanceof Projection) {
        projections.add(((Projection) unary).getProjectionElemList());
    } else {
        projections.addAll(((MultiProjection) unary).getProjections());
    }
    return getConstructGraphVarOrder(projections);
}

Example 15 with ProjectionElemList

use of org.openrdf.query.algebra.ProjectionElemList in project incubator-rya by apache.

the class MultiProjectionEvaluator method make.

/**
 * Make a {@link MultiProjectionEvaluator} that processes the logic of a {@link MultiProjection}.
 *
 * @param multiProjection - Defines the projections that will be processed. (not null)
 * @param bNodeIdFactory - Creates the IDs for Blank Nodes. (not null)
 * @return A {@link MultiProjectionEvaluator} for the provided {@link MultiProjection}.
 */
public static MultiProjectionEvaluator make(final MultiProjection multiProjection, final BNodeIdFactory bNodeIdFactory) {
    requireNonNull(multiProjection);
    // Figure out if there are extensions.
    final TupleExpr arg = multiProjection.getArg();
    final Optional<Extension> extension = (arg instanceof Extension) ? Optional.of((Extension) arg) : Optional.empty();
    // If there are, iterate through them and find any blank node source names.
    final Set<String> blankNodeSourceNames = new HashSet<>();
    if (extension.isPresent()) {
        for (final ExtensionElem elem : extension.get().getElements()) {
            if (elem.getExpr() instanceof BNodeGenerator) {
                blankNodeSourceNames.add(elem.getName());
            }
        }
    }
    // Create a ProjectionEvaluator for each projection that is part of the multi.
    final Set<ProjectionEvaluator> projections = new HashSet<>();
    for (final ProjectionElemList projectionElemList : multiProjection.getProjections()) {
        projections.add(new ProjectionEvaluator(projectionElemList, extension));
    }
    return new MultiProjectionEvaluator(projections, blankNodeSourceNames, bNodeIdFactory);
}