Examples with BasicPattern org.apache.jena.sparql.core.BasicPattern used on opensource projects

Example 26 with BasicPattern

use of org.apache.jena.sparql.core.BasicPattern in project jena by apache.

the class FormatterElement method visit.

@Override
public void visit(ElementPathBlock el) {
    // Write path block - don't put in a final trailing "." 
    if (el.isEmpty()) {
        out.println("# Empty BGP");
        return;
    }
    // Split into BGP-path-BGP-...
    // where the BGPs may be empty.
    PathBlock pBlk = el.getPattern();
    BasicPattern bgp = new BasicPattern();
    // Has anything been output?
    boolean first = true;
    for (TriplePath tp : pBlk) {
        if (tp.isTriple()) {
            bgp.add(tp.asTriple());
            continue;
        }
        if (!bgp.isEmpty()) {
            if (!first)
                out.println(" .");
            flush(bgp);
            first = false;
        }
        if (!first)
            out.println(" .");
        // Path
        printSubject(tp.getSubject());
        out.print(" ");
        PathWriter.write(out, tp.getPath(), context.getPrologue());
        out.print(" ");
        printObject(tp.getObject());
        first = false;
    }
    // Flush any stored triple patterns.
    if (!bgp.isEmpty()) {
        if (!first)
            out.println(" .");
        flush(bgp);
        first = false;
    }
}

Example 27 with BasicPattern

use of org.apache.jena.sparql.core.BasicPattern in project jena by apache.

the class Eval method evalQuadPattern.

static Table evalQuadPattern(OpQuadPattern opQuad, Evaluator evaluator) {
    if (opQuad.isEmpty())
        return TableFactory.createUnit();
    ExecutionContext cxt = evaluator.getExecContext();
    DatasetGraph ds = cxt.getDataset();
    BasicPattern pattern = opQuad.getBasicPattern();
    if (!opQuad.getGraphNode().isVariable()) {
        if (!opQuad.getGraphNode().isURI()) {
            throw new ARQInternalErrorException("Not a URI or variable: " + opQuad.getGraphNode());
        }
        Graph g = null;
        if (opQuad.isDefaultGraph())
            g = ds.getDefaultGraph();
        else
            g = ds.getGraph(opQuad.getGraphNode());
        if (g == null)
            return new TableEmpty();
        ExecutionContext cxt2 = new ExecutionContext(cxt, g);
        QueryIterator qIter = executeBGP(pattern, QueryIterRoot.create(cxt2), cxt2);
        return TableFactory.create(qIter);
    } else {
        // Variable.
        Var gVar = Var.alloc(opQuad.getGraphNode());
        // Or just just devolve to OpGraph and get OpUnion chain of OpJoin
        QueryIterConcat concat = new QueryIterConcat(cxt);
        for (Iterator<Node> graphNodes = cxt.getDataset().listGraphNodes(); graphNodes.hasNext(); ) {
            Node gn = graphNodes.next();
            //Op tableVarURI = TableFactory.create(gn.getName(), Node.createURI(uri)) ;
            Graph g = cxt.getDataset().getGraph(gn);
            Binding b = BindingFactory.binding(BindingRoot.create(), gVar, gn);
            ExecutionContext cxt2 = new ExecutionContext(cxt, g);
            // Eval the pattern, eval the variable, join.
            // Pattern may be non-linear in the variable - do a pure execution.  
            Table t1 = TableFactory.create(gVar, gn);
            QueryIterator qIter = executeBGP(pattern, QueryIterRoot.create(cxt2), cxt2);
            Table t2 = TableFactory.create(qIter);
            Table t3 = evaluator.join(t1, t2);
            concat.add(t3.iterator(cxt2));
        }
        return TableFactory.create(concat);
    }
}

Example 28 with BasicPattern

use of org.apache.jena.sparql.core.BasicPattern in project jena by apache.

the class Template method getGraphPattern.

public Map<Node, BasicPattern> getGraphPattern() {
    List<Quad> quads = getQuads();
    HashMap<Node, BasicPattern> graphs = new HashMap<>();
    for (Quad q : quads) {
        BasicPattern bgp = graphs.get(q.getGraph());
        if (bgp == null) {
            bgp = new BasicPattern();
            graphs.put(q.getGraph(), bgp);
        }
        bgp.add(q.asTriple());
    }
    return graphs;
}

Example 29 with BasicPattern

use of org.apache.jena.sparql.core.BasicPattern in project jena by apache.

the class tdbreorder method main.

public static void main(String... args) {
    if (args.length != 2) {
        System.err.println("Usage: PATTERN STATS");
        System.exit(1);
    }
    LogCtl.enable(StatsMatcher.class);
    LogCtl.enable(ReorderTransformationSubstitution.class);
    if (args.length != 2) {
        System.err.println("Usage: op stats");
        System.exit(1);
    }
    String pattern = args[0];
    String statsFile = args[1];
    Op op = SSE.readOp(pattern);
    BasicPattern bgp;
    if (op instanceof OpQuadPattern) {
        bgp = ((OpQuadPattern) op).getBasicPattern();
    } else if (op instanceof OpBGP) {
        bgp = ((OpBGP) op).getPattern();
    } else {
        System.err.println("Not a quad or triple pattern");
        System.exit(2);
        bgp = null;
    }
    ReorderTransformation reorder = chooseReorder(statsFile);
    // ReorderTransformation reorder = ReorderLib.fixed() ;
    BasicPattern bgp2 = reorder.reorder(bgp);
    System.out.println();
    print(bgp);
    System.out.println();
    System.out.println(" ======== >>>>>>>>");
    print(bgp2);
    System.out.println();
}

Example 30 with BasicPattern

use of org.apache.jena.sparql.core.BasicPattern in project jena by apache.

the class LibSDB method findTriples.

/** Find triples, in the default graph or a named graph. */
public static Iterator<Triple> findTriples(DatasetGraph dsg, Node g, Node s, Node p, Node o) {
    if (Var.isVar(g))
        throw new InternalErrorException("Graph node is a variable : " + g);
    final Node vs = varOrConst(s, "s");
    final Node vp = varOrConst(p, "p");
    final Node vo = varOrConst(o, "o");
    // Evaluate as an algebra expression
    Triple triple = new Triple(vs, vp, vo);
    BasicPattern pattern = new BasicPattern();
    pattern.add(triple);
    Op op = (g != null) ? new OpQuadPattern(g, pattern) : new OpBGP(pattern);
    Plan plan = QueryEngineSDB.getFactory().create(op, dsg, BindingRoot.create(), null);
    QueryIterator qIter = plan.iterator();
    Iterator<Binding> iter;
    if (SDB.getContext().isTrue(SDB.streamGraphAPI)) {
        // Assumes iterator closed properly.
        iter = qIter;
    } else {
        // ---- Safe version: 
        List<Binding> x = Iter.toList(qIter);
        Iterator<Binding> qIter2 = x.iterator();
        qIter.close();
        iter = qIter2;
    }
    return Iter.map(iter, (b) -> bindingToTriple(vs, vp, vo, b));
}