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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  
19  package org.apache.hadoop.hbase.codec.prefixtree.encode.other;
20  
21  import org.apache.hadoop.classification.InterfaceAudience;
22  
23  /**
24   * Detect if every KV has the same KeyValue.Type, in which case we don't need to store it for each
25   * KV.  If(allSameType) during conversion to byte[], then we can store the "onlyType" in blockMeta,
26   * therefore not repeating it for each cell and saving 1 byte per cell.
27   */
28  @InterfaceAudience.Private
29  public class CellTypeEncoder {
30  
31    /************* fields *********************/
32  
33    protected boolean pendingFirstType = true;
34    protected boolean allSameType = true;
35    protected byte onlyType;
36  
37  
38    /************* construct *********************/
39  
40    public void reset() {
41      pendingFirstType = true;
42      allSameType = true;
43    }
44  
45  
46    /************* methods *************************/
47  
48    public void add(byte type) {
49      if (pendingFirstType) {
50        onlyType = type;
51        pendingFirstType = false;
52      } else if (onlyType != type) {
53        allSameType = false;
54      }
55    }
56  
57  
58    /**************** get/set **************************/
59  
60    public boolean areAllSameType() {
61      return allSameType;
62    }
63  
64    public byte getOnlyType() {
65      return onlyType;
66    }
67  
68  }