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1   /**
2    * Licensed to the Apache Software Foundation (ASF) under one
3    * or more contributor license agreements.  See the NOTICE file
4    * distributed with this work for additional information
5    * regarding copyright ownership.  The ASF licenses this file
6    * to you under the Apache License, Version 2.0 (the
7    * "License"); you may not use this file except in compliance
8    * with the License.  You may obtain a copy of the License at
9    *
10   *     http://www.apache.org/licenses/LICENSE-2.0
11   *
12   * Unless required by applicable law or agreed to in writing, software
13   * distributed under the License is distributed on an "AS IS" BASIS,
14   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15   * See the License for the specific language governing permissions and
16   * limitations under the License.
17   */
18  package org.apache.hadoop.hbase.coprocessor;
19  
20  import java.io.IOException;
21  import java.util.ArrayList;
22  import java.util.List;
23  
24  import org.apache.commons.logging.Log;
25  import org.apache.commons.logging.LogFactory;
26  import org.apache.hadoop.hbase.Cell;
27  import org.apache.hadoop.hbase.CellUtil;
28  import org.apache.hadoop.hbase.Coprocessor;
29  import org.apache.hadoop.hbase.CoprocessorEnvironment;
30  import org.apache.hadoop.hbase.HConstants;
31  import org.apache.hadoop.hbase.client.Scan;
32  import org.apache.hadoop.hbase.coprocessor.protobuf.generated.ColumnAggregationWithNullResponseProtos.ColumnAggregationServiceNullResponse;
33  import org.apache.hadoop.hbase.coprocessor.protobuf.generated.ColumnAggregationWithNullResponseProtos.ColumnAggregationNullResponseSumRequest;
34  import org.apache.hadoop.hbase.coprocessor.protobuf.generated.ColumnAggregationWithNullResponseProtos.ColumnAggregationNullResponseSumResponse;
35  import org.apache.hadoop.hbase.protobuf.ResponseConverter;
36  import org.apache.hadoop.hbase.regionserver.HRegion;
37  import org.apache.hadoop.hbase.regionserver.InternalScanner;
38  import org.apache.hadoop.hbase.util.Bytes;
39  
40  import com.google.protobuf.RpcCallback;
41  import com.google.protobuf.RpcController;
42  import com.google.protobuf.Service;
43  
44  /**
45   * Test coprocessor endpoint that always returns {@code null} for requests to the last region
46   * in the table.  This allows tests to provide assurance of correct {@code null} handling for
47   * response values.
48   */
49  public class ColumnAggregationEndpointNullResponse
50      extends
51      ColumnAggregationServiceNullResponse
52  implements Coprocessor, CoprocessorService  {
53    static final Log LOG = LogFactory.getLog(ColumnAggregationEndpointNullResponse.class);
54    private RegionCoprocessorEnvironment env = null;
55    @Override
56    public Service getService() {
57      return this;
58    }
59  
60    @Override
61    public void start(CoprocessorEnvironment env) throws IOException {
62      if (env instanceof RegionCoprocessorEnvironment) {
63        this.env = (RegionCoprocessorEnvironment)env;
64        return;
65      }
66      throw new CoprocessorException("Must be loaded on a table region!");
67    }
68  
69    @Override
70    public void stop(CoprocessorEnvironment env) throws IOException {
71      // Nothing to do.
72    }
73  
74    @Override
75    public void sum(RpcController controller, ColumnAggregationNullResponseSumRequest request,
76         RpcCallback<ColumnAggregationNullResponseSumResponse> done) {
77      // aggregate at each region
78      Scan scan = new Scan();
79      // Family is required in pb. Qualifier is not.
80      byte[] family = request.getFamily().toByteArray();
81      byte[] qualifier = request.hasQualifier() ? request.getQualifier().toByteArray() : null;
82      if (request.hasQualifier()) {
83        scan.addColumn(family, qualifier);
84      } else {
85        scan.addFamily(family);
86      }
87      int sumResult = 0;
88      InternalScanner scanner = null;
89      try {
90        HRegion region = this.env.getRegion();
91        // for the last region in the table, return null to test null handling
92        if (Bytes.equals(region.getEndKey(), HConstants.EMPTY_END_ROW)) {
93          done.run(null);
94          return;
95        }
96        scanner = region.getScanner(scan);
97        List<Cell> curVals = new ArrayList<Cell>();
98        boolean hasMore = false;
99        do {
100         curVals.clear();
101         hasMore = scanner.next(curVals);
102         for (Cell kv : curVals) {
103           if (CellUtil.matchingQualifier(kv, qualifier)) {
104             sumResult += Bytes.toInt(kv.getValueArray(), kv.getValueOffset());
105           }
106         }
107       } while (hasMore);
108     } catch (IOException e) {
109       ResponseConverter.setControllerException(controller, e);
110       // Set result to -1 to indicate error.
111       sumResult = -1;
112       LOG.info("Setting sum result to -1 to indicate error", e);
113     } finally {
114       if (scanner != null) {
115         try {
116           scanner.close();
117         } catch (IOException e) {
118           ResponseConverter.setControllerException(controller, e);
119           sumResult = -1;
120           LOG.info("Setting sum result to -1 to indicate error", e);
121         }
122       }
123     }
124     done.run(ColumnAggregationNullResponseSumResponse.newBuilder().setSum(sumResult)
125       .build());
126     LOG.info("Returning sum " + sumResult + " for region " +
127         Bytes.toStringBinary(env.getRegion().getRegionName()));
128   }
129 }