Github user meiercaleb commented on a diff in the pull request:
https://github.com/apache/incubator-rya/pull/251#discussion_r153630587
--- Diff:
extras/rya.pcj.fluo/pcj.fluo.app/src/main/java/org/apache/rya/indexing/pcj/fluo/app/query/StatementPatternIdManager.java
---
@@ -0,0 +1,85 @@
+/*
+ * 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.pcj.fluo.app.query;
+
+import static
org.apache.rya.indexing.pcj.fluo.app.IncrementalUpdateConstants.STATEMENT_PATTERN_ID;
+import static
org.apache.rya.indexing.pcj.fluo.app.IncrementalUpdateConstants.VAR_DELIM;
+import static
org.apache.rya.indexing.pcj.fluo.app.query.FluoQueryColumns.STATEMENT_PATTERN_IDS;
+import static
org.apache.rya.indexing.pcj.fluo.app.query.FluoQueryColumns.STATEMENT_PATTERN_IDS_HASH;
+
+import java.util.HashSet;
+import java.util.Set;
+
+import org.apache.fluo.api.client.TransactionBase;
+import org.apache.fluo.api.data.Bytes;
+
+import com.google.common.base.Joiner;
+import com.google.common.base.Optional;
+import com.google.common.collect.Sets;
+import com.google.common.hash.Hashing;
+
+/**
+ * Utility class for updating and removing StatementPattern nodeIds in the
Fluo table. All StatementPattern nodeIds are
+ * stored in a single set under a single entry in the Fluo table. This is
to eliminate the need for a scan to find all
+ * StatementPattern nodeIds every time a new Triple enters the Fluo table.
Instead, the nodeIds are cached locally, and
+ * only updated when the local hash of the nodeId set is dirty (not equal
to the hash in the Fluo table).
+ */
+public class StatementPatternIdManager {
+
+ /**
+ * Add specified Set of ids to the Fluo table with Column {@link
FluoQueryColumns#STATEMENT_PATTERN_IDS}. Also
+ * updates the hash of the updated nodeId Set and writes that to the
Column
+ * {@link FluoQueryColumns#STATEMENT_PATTERN_IDS_HASH}
+ *
+ * @param tx
+ * @param ids - ids to add to the StatementPattern nodeId Set
+ */
+ public static void addStatementPatternIds(TransactionBase tx,
Set<String> ids) {
+ Optional<Bytes> val =
Optional.fromNullable(tx.get(Bytes.of(STATEMENT_PATTERN_ID),
STATEMENT_PATTERN_IDS));
+ StringBuilder builder = new StringBuilder();
+ if (val.isPresent()) {
+ builder.append(val.get().toString());
+ builder.append(VAR_DELIM);
+ }
+ String idString =
builder.append(Joiner.on(VAR_DELIM).join(ids)).toString();
+ tx.set(Bytes.of(STATEMENT_PATTERN_ID), STATEMENT_PATTERN_IDS,
Bytes.of(idString));
+ tx.set(Bytes.of(STATEMENT_PATTERN_ID), STATEMENT_PATTERN_IDS_HASH,
Bytes.of(Hashing.sha256().hashString(idString).toString()));
+ }
+
+ /**
+ * Remove specified Set of ids from the Fluo table and updates the
entry with Column
+ * {@link FluoQueryColumns#STATEMENT_PATTERN_IDS}. Also updates the
hash of the updated nodeId Set and writes that
+ * to the Column {@link FluoQueryColumns#STATEMENT_PATTERN_IDS_HASH}
+ *
+ * @param tx
--- End diff --
Done.
---
