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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.client;
19  
20  import java.io.IOException;
21  
22  import org.apache.hadoop.hbase.Cell;
23  import org.apache.hadoop.hbase.classification.InterfaceAudience;
24  import org.apache.hadoop.hbase.exceptions.DeserializationException;
25  import org.apache.hadoop.hbase.filter.FilterBase;
26  import org.apache.hadoop.hbase.util.Bytes;
27  
28  @InterfaceAudience.Private
29  public final class ColumnCountOnRowFilter extends FilterBase {
30  
31    private final int limit;
32  
33    private int count = 0;
34  
35    public ColumnCountOnRowFilter(int limit) {
36      this.limit = limit;
37    }
38  
39    @Override
40    public ReturnCode filterKeyValue(Cell v) throws IOException {
41      count++;
42      return count > limit ? ReturnCode.NEXT_ROW : ReturnCode.INCLUDE;
43    }
44  
45    @Override
46    public void reset() throws IOException {
47      this.count = 0;
48    }
49  
50    @Override
51    public byte[] toByteArray() throws IOException {
52      return Bytes.toBytes(limit);
53    }
54  
55    public static ColumnCountOnRowFilter parseFrom(byte[] bytes) throws DeserializationException {
56      return new ColumnCountOnRowFilter(Bytes.toInt(bytes));
57    }
58  }