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1   /*
2    * Copyright (c) 2010.  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.statement;
22  
23  import org.apache.hadoop.hbase.hbql.client.AsyncExecutorManager;
24  import org.apache.hadoop.hbase.hbql.client.ExecutionResults;
25  import org.apache.hadoop.hbase.hbql.client.HBqlException;
26  import org.apache.hadoop.hbase.hbql.impl.HConnectionImpl;
27  
28  public class DropAsyncExecutorStatement extends GenericStatement implements ConnectionStatement {
29  
30      private final String name;
31  
32      public DropAsyncExecutorStatement(final StatementPredicate predicate, final String name) {
33          super(predicate);
34          this.name = name;
35      }
36  
37      private String getName() {
38          return this.name;
39      }
40  
41      protected ExecutionResults execute(final HConnectionImpl conn) throws HBqlException {
42  
43          final String msg;
44          if (!AsyncExecutorManager.asyncExecutorExists(this.getName())) {
45              msg = "Async Executor " + this.getName() + " does not exist";
46          }
47          else {
48              AsyncExecutorManager.dropAsyncExecutor(this.getName());
49              msg = "Async Executor " + this.getName() + " dropped.";
50          }
51          return new ExecutionResults(msg);
52      }
53  
54  
55      public static String usage() {
56          return "DROP ASYNC EXECUTOR name [IF bool_expr]";
57      }
58  }