Github user solzy commented on a diff in the pull request:
https://github.com/apache/phoenix/pull/308#discussion_r202593990
--- Diff:
phoenix-core/src/main/java/org/apache/phoenix/iterate/ClientHashAggregatingResultIterator.java
---
@@ -0,0 +1,155 @@
+/*
+ * 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.phoenix.iterate;
+
+import static org.apache.phoenix.query.QueryConstants.AGG_TIMESTAMP;
+import static org.apache.phoenix.query.QueryConstants.SINGLE_COLUMN;
+import static org.apache.phoenix.query.QueryConstants.SINGLE_COLUMN_FAMILY;
+
+import java.io.IOException;
+import java.sql.SQLException;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Map;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.List;
+
+import org.apache.hadoop.hbase.Cell;
+import org.apache.hadoop.hbase.KeyValue;
+import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
+import org.apache.phoenix.expression.Expression;
+import org.apache.phoenix.expression.aggregator.Aggregator;
+import org.apache.phoenix.expression.aggregator.Aggregators;
+import org.apache.phoenix.schema.tuple.MultiKeyValueTuple;
+import org.apache.phoenix.schema.tuple.Tuple;
+import org.apache.phoenix.util.KeyValueUtil;
+import org.apache.phoenix.util.TupleUtil;
+
+/**
+ *
+ * This class implements client-side hash aggregation in memory.
+ * Issue https://issues.apache.org/jira/browse/PHOENIX-4751.
+ *
+ */
+public class ClientHashAggregatingResultIterator
+ implements AggregatingResultIterator {
+
+ private static final int HASH_AGG_INIT_SIZE = 64*1024;
+ private static final byte[] UNITIALIZED_KEY_BUFFER = new byte[0];
+ private final ResultIterator resultIterator;
+ private final Aggregators aggregators;
+ private final List<Expression> groupByExpressions;
+ private HashMap<ImmutableBytesWritable, Aggregator[]> hash;
+ private List<ImmutableBytesWritable> keyList;
+ private Iterator<ImmutableBytesWritable> keyIterator;
+
+ public ClientHashAggregatingResultIterator(ResultIterator
resultIterator, Aggregators aggregators, List<Expression> groupByExpressions) {
+ if (resultIterator == null) throw new NullPointerException();
+ if (aggregators == null) throw new NullPointerException();
+ if (groupByExpressions == null) throw new NullPointerException();
+ this.resultIterator = resultIterator;
+ this.aggregators = aggregators;
+ this.groupByExpressions = groupByExpressions;
+ }
+
+ @Override
+ public Tuple next() throws SQLException {
+ if (keyIterator == null) {
+ populateHash();
+ sortKeys();
+ keyIterator = keyList.iterator();
+ }
+
+ if (!keyIterator.hasNext()) {
+ return null;
+ }
+
+ ImmutableBytesWritable key = keyIterator.next();
+ Aggregator[] rowAggregators = hash.get(key);
+ byte[] value = aggregators.toBytes(rowAggregators);
+ Tuple tuple = wrapKeyValueAsResult(KeyValueUtil.newKeyValue(key,
SINGLE_COLUMN_FAMILY, SINGLE_COLUMN, AGG_TIMESTAMP, value, 0, value.length));
+ return tuple;
+ }
+
+ @Override
+ public void close() throws SQLException {
+ keyIterator = null;
+ keyList = null;
+ hash = null;
+ resultIterator.close();
+ }
+
+ @Override
+ public Aggregator[] aggregate(Tuple result) {
+ Aggregator[] rowAggregators = aggregators.getAggregators();
+ aggregators.reset(rowAggregators);
+ aggregators.aggregate(rowAggregators, result);
+ return rowAggregators;
+ }
+
+ @Override
+ public void explain(List<String> planSteps) {
+ resultIterator.explain(planSteps);
+ }
+
+ @Override
+ public String toString() {
+ return "ClientHashAggregatingResultIterator [resultIterator="
+ + resultIterator + ", aggregators=" + aggregators + ",
groupByExpressions="
+ + groupByExpressions + "]";
+ }
+
+ // Copied from ClientGroupedAggregatingResultIterator
+ protected ImmutableBytesWritable getGroupingKey(Tuple tuple,
ImmutableBytesWritable ptr) throws SQLException {
+ try {
+ ImmutableBytesWritable key =
TupleUtil.getConcatenatedValue(tuple, groupByExpressions);
+ ptr.set(key.get(), key.getOffset(), key.getLength());
+ return ptr;
+ } catch (IOException e) {
+ throw new SQLException(e);
+ }
+ }
+
+ // Copied from ClientGroupedAggregatingResultIterator
+ protected Tuple wrapKeyValueAsResult(KeyValue keyValue) {
+ return new MultiKeyValueTuple(Collections.<Cell>
singletonList(keyValue));
+ }
+
+ private void populateHash() throws SQLException {
--- End diff --
@geraldss Sorry for late reply. i did not find some handle for OOM on the
client, which will be affects stability when uses as QueryServer. anyway, we
can improve these features in the future. Thanks for your response , good job.
---
