Github user meiercaleb commented on a diff in the pull request:
https://github.com/apache/incubator-rya/pull/172#discussion_r159935133
--- Diff:
extras/indexing/src/main/java/org/apache/rya/indexing/mongodb/pcj/PcjQueryNode.java
---
@@ -0,0 +1,172 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.rya.indexing.mongodb.pcj;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashSet;
+
+import org.apache.accumulo.core.security.Authorizations;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.log4j.Logger;
+import org.apache.rya.api.utils.IteratorWrapper;
+import org.apache.rya.indexing.external.tupleSet.ExternalTupleSet;
+import org.apache.rya.indexing.external.tupleSet.ParsedQueryUtil;
+import org.apache.rya.indexing.pcj.matching.PCJOptimizerUtilities;
+import org.apache.rya.indexing.pcj.storage.PcjException;
+import
org.apache.rya.indexing.pcj.storage.PrecomputedJoinStorage.CloseableIterator;
+import org.apache.rya.indexing.pcj.storage.mongo.MongoPcjDocuments;
+import org.apache.rya.rdftriplestore.evaluation.ExternalBatchingIterator;
+import org.openrdf.query.BindingSet;
+import org.openrdf.query.MalformedQueryException;
+import org.openrdf.query.QueryEvaluationException;
+import org.openrdf.query.algebra.Projection;
+import org.openrdf.query.algebra.TupleExpr;
+import org.openrdf.query.parser.ParsedTupleQuery;
+import org.openrdf.query.parser.sparql.SPARQLParser;
+
+import com.google.common.base.Joiner;
+import com.google.common.base.Optional;
+import com.google.common.base.Preconditions;
+
+import edu.umd.cs.findbugs.annotations.DefaultAnnotation;
+import edu.umd.cs.findbugs.annotations.NonNull;
+import info.aduna.iteration.CloseableIteration;
+
+/**
+ * Indexing Node for PCJs expressions to be inserted into execution plan to
+ * delegate entity portion of query to {@link MongoPrecomputedJoinIndexer}.
+ */
+@DefaultAnnotation(NonNull.class)
+public class PcjQueryNode extends ExternalTupleSet implements
ExternalBatchingIterator {
+ private static final Logger log = Logger.getLogger(PcjQueryNode.class);
+ private final String tablename;
+ private final PcjIndexer indexer;
+ private final MongoPcjDocuments pcjDocs;
+
+ /**
+ * Creates a new {@link PcjQueryNode}.
+ *
+ * @param sparql - name of sparql query whose results will be stored
in PCJ table
+ * @param conf - Rya Configuration
+ * @param tablename - name of an existing PCJ table
+ *
+ * @throws MalformedQueryException - The SPARQL query needs to contain
a projection.
+ */
+ public PcjQueryNode(final String sparql, final String tablename, final
MongoPcjDocuments pcjDocs) throws MalformedQueryException {
+ this.pcjDocs = checkNotNull(pcjDocs);
+ indexer = new MongoPrecomputedJoinIndexer();
+ this.tablename = tablename;
+ final SPARQLParser sp = new SPARQLParser();
+ final ParsedTupleQuery pq = (ParsedTupleQuery)
sp.parseQuery(sparql, null);
+ final TupleExpr te = pq.getTupleExpr();
+ Preconditions.checkArgument(PCJOptimizerUtilities.isPCJValid(te),
"TupleExpr is an invalid PCJ.");
+
+ final Optional<Projection> projection = new
ParsedQueryUtil().findProjection(pq);
+ if (!projection.isPresent()) {
+ throw new MalformedQueryException("SPARQL query '" + sparql +
"' does not contain a Projection.");
+ }
+ setProjectionExpr(projection.get());
+ }
+
+ /**
+ * Creates a new {@link PcjQueryNode}.
+ *
+ * @param accCon - connection to a valid Accumulo instance
+ * @param tablename - name of an existing PCJ table
+ */
+ public PcjQueryNode(final Configuration conf, final String tablename) {
+ indexer = new MongoPrecomputedJoinIndexer();
+ pcjDocs = indexer.getPcjStorage(conf);
+ this.tablename = tablename;
+ }
+
+ /**
+ * returns size of table for query planning
+ */
+ @Override
+ public double cardinality() {
+ double cardinality = 0;
+ try {
+ cardinality =
pcjDocs.getPcjMetadata(tablename).getCardinality();
+ } catch (final PcjException e) {
+ log.error("The PCJ has not been created, so has no
cardinality.", e);
+ }
+ return cardinality;
+ }
+
+ @Override
+ public CloseableIteration<BindingSet, QueryEvaluationException>
evaluate(final BindingSet bindingset)
+ throws QueryEvaluationException {
+ return this.evaluate(Collections.singleton(bindingset));
+ }
+
+ /**
+ * Core evaluation method used during query evaluation - given a
collection
+ * of binding set constraints, this method finds common binding labels
+ * between the constraints and table, uses those to build a query of
mongodb,
+ * and creates a solution binding set by iterating of
+ * the scan results.
+ *
+ * @param bindingset - collection of {@link BindingSet}s to be joined
with PCJ
+ * @return - CloseableIteration over joined results
+ */
+ @Override
+ public CloseableIteration<BindingSet, QueryEvaluationException>
evaluate(final Collection<BindingSet> bindingset)
+ throws QueryEvaluationException {
+
+ if (bindingset.isEmpty()) {
+ return new IteratorWrapper<BindingSet,
QueryEvaluationException>(new HashSet<BindingSet>().iterator());
+ }
+ final CloseableIterator<BindingSet> iter =
pcjDocs.getResults(tablename, new Authorizations(), bindingset);
+ return new CloseableIteration<BindingSet,
QueryEvaluationException>() {
+ @Override
+ public boolean hasNext() throws QueryEvaluationException {
+ return iter.hasNext();
+ }
+
+ @Override
+ public BindingSet next() throws QueryEvaluationException {
+ final BindingSet bs = iter.next();
+ return bs;
+ }
+
+ @Override
+ public void remove() throws QueryEvaluationException {
+ iter.remove();
+ }
+
+ @Override
+ public void close() throws QueryEvaluationException {
+ try {
+ iter.close();
+ } catch (final Exception e) {
+ throw new QueryEvaluationException(e.getMessage(), e);
+ }
+ }
+ };
+ }
+
+ @Override
+ public String getSignature() {
+ return "(Mongo PcjQueryNode) " + Joiner.on(",
").join(super.getTupleExpr().getProjectionElemList().getElements()).replaceAll("\\s+",
" ");
--- End diff --
Change the name of the class to match the signature.
---
