Github user ejwhite922 commented on a diff in the pull request:
https://github.com/apache/incubator-rya/pull/172#discussion_r160453846
--- Diff:
extras/indexing/src/main/java/org/apache/rya/indexing/mongodb/pcj/BasePcjIndexer.java
---
@@ -0,0 +1,138 @@
+/*
+ * 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.checkState;
+import static java.util.Collections.singleton;
+import static java.util.Objects.requireNonNull;
+import static java.util.stream.Collectors.groupingBy;
+
+import java.io.IOException;
+import java.util.Collection;
+import java.util.List;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.Set;
+import java.util.concurrent.atomic.AtomicReference;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.rya.api.domain.RyaStatement;
+import org.apache.rya.api.domain.RyaURI;
+import org.apache.rya.indexing.entity.model.Entity;
+import org.apache.rya.indexing.entity.storage.EntityStorage;
+import
org.apache.rya.indexing.entity.storage.EntityStorage.EntityStorageException;
+import org.apache.rya.indexing.pcj.storage.mongo.MongoPcjDocuments;
+import org.apache.rya.mongodb.MongoDBRdfConfiguration;
+import org.apache.rya.mongodb.MongoSecondaryIndex;
+import org.openrdf.model.URI;
+
+import edu.umd.cs.findbugs.annotations.DefaultAnnotation;
+import edu.umd.cs.findbugs.annotations.NonNull;
+
+/**
+ * A base class that may be used to update an {@link EntityStorage} as new
+ * {@link RyaStatement}s are added to/removed from the Rya instance.
+ */
+@DefaultAnnotation(NonNull.class)
+public abstract class BasePcjIndexer implements PcjIndexer,
MongoSecondaryIndex {
+
+ private final AtomicReference<MongoDBRdfConfiguration> configuration =
new AtomicReference<>();
+ private final AtomicReference<MongoPcjDocuments> pcjDocs = new
AtomicReference<>();
+
+ @Override
+ public void setConf(final Configuration conf) {
+ requireNonNull(conf);
+ pcjDocs.set( getPcjStorage(conf) );
+ }
+
+ @Override
+ public Configuration getConf() {
+ return configuration.get();
+ }
+
+ @Override
+ public void storeStatement(final RyaStatement statement) throws
IOException {
+ requireNonNull(statement);
+ storeStatements( singleton(statement) );
+ }
+
+ @Override
+ public void storeStatements(final Collection<RyaStatement> statements)
throws IOException {
+ requireNonNull(statements);
+
+ final Map<RyaURI,List<RyaStatement>> groupedBySubject =
statements.stream()
+ .collect(groupingBy(RyaStatement::getSubject));
+
+ for(final Entry<RyaURI, List<RyaStatement>> entry :
groupedBySubject.entrySet()) {
+ try {
+ updateEntity(entry.getKey(), entry.getValue());
+ } catch (final EntityStorageException e) {
+ throw new IOException("Failed to update the Entity
index.", e);
+ }
+ }
+ }
+
+ /**
+ * Updates a {@link Entity} to reflect new {@link RyaStatement}s.
+ *
+ * @param subject - The Subject of the {@link Entity} the statements
are for. (not null)
+ * @param statements - Statements that the {@link Entity} will be
updated with. (not null)
+ */
+ private void updateEntity(final RyaURI subject, final
Collection<RyaStatement> statements) throws EntityStorageException {
+ requireNonNull(subject);
+ requireNonNull(statements);
+
+ final MongoPcjDocuments pcjDocStore = pcjDocs.get();
+ checkState(pcjDocStore != null, "Must set this indexers
configuration before storing statements.");
+ }
+
+ @Override
+ public void deleteStatement(final RyaStatement statement) throws
IOException {
+ requireNonNull(statement);
+
+ final MongoPcjDocuments pcjDocStore = pcjDocs.get();
+ checkState(pcjDocStore != null, "Must set this indexers
configuration before storing statements.");
--- End diff --
same
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