View Javadoc

1   /*
2    * Copyright (c) 2011.  The Apache Software Foundation
3    *
4    * Licensed to the Apache Software Foundation (ASF) under one
5    * or more contributor license agreements.  See the NOTICE file
6    * distributed with this work for additional information
7    * regarding copyright ownership.  The ASF licenses this file
8    * to you under the Apache License, Version 2.0 (the
9    * "License"); you may not use this file except in compliance
10   * with the License.  You may obtain a copy of the License at
11   *
12   *     http://www.apache.org/licenses/LICENSE-2.0
13   *
14   * Unless required by applicable law or agreed to in writing, software
15   * distributed under the License is distributed on an "AS IS" BASIS,
16   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17   * See the License for the specific language governing permissions and
18   * limitations under the License.
19   */
20  
21  package org.apache.hadoop.hbase.hbql.impl;
22  
23  import org.apache.expreval.client.NullColumnValueException;
24  import org.apache.expreval.client.ResultMissingColumnException;
25  import org.apache.hadoop.hbase.client.Result;
26  import org.apache.hadoop.hbase.hbql.client.HBqlException;
27  import org.apache.hadoop.hbase.hbql.statement.select.SelectExpressionContext;
28  
29  public class AggregateValue extends ColumnValue {
30  
31      final SelectExpressionContext context;
32      boolean valueSet = false;
33  
34      public AggregateValue(final String name, final SelectExpressionContext context) {
35          super(name);
36          this.context = context;
37      }
38  
39      private SelectExpressionContext getContext() {
40          return this.context;
41      }
42  
43      public boolean isValueSet() {
44          return this.valueSet;
45      }
46  
47      private void setValueSet(final boolean valueSet) {
48          this.valueSet = valueSet;
49      }
50  
51      public void initAggregateValue() throws HBqlException {
52          this.getContext().initAggregateValue(this);
53      }
54  
55      public void applyValues(final Result result) throws HBqlException,
56                                                          ResultMissingColumnException,
57                                                          NullColumnValueException {
58          this.getContext().applyResultToAggregateValue(this, result);
59      }
60  
61      public Object getValue() {
62          return super.getCurrentValue();
63      }
64  
65      public void setValue(final Object val) {
66          super.setCurrentValue(0, val);
67          setValueSet(true);
68      }
69  }