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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.regionserver.throttle;
19  
20  import java.util.concurrent.atomic.AtomicInteger;
21  
22  import org.apache.hadoop.hbase.classification.InterfaceAudience;
23  import org.apache.hadoop.hbase.regionserver.Store;
24  
25  /**
26   * Helper methods for throttling
27   */
28  @InterfaceAudience.Private
29  public final class ThroughputControlUtil {
30    private ThroughputControlUtil() {
31    }
32  
33    private static final AtomicInteger NAME_COUNTER = new AtomicInteger(0);
34    private static final String NAME_DELIMITER = "#";
35  
36    /**
37     * Generate a name for throttling, to prevent name conflict when multiple IO operation running
38     * parallel on the same store.
39     * @param store the Store instance on which IO operation is happening
40     * @param opName Name of the IO operation, e.g. "flush", "compaction", etc.
41     * @return The name for throttling
42     */
43    public static String getNameForThrottling(final Store store, final String opName) {
44      int counter;
45      for (;;) {
46        counter = NAME_COUNTER.get();
47        int next = counter == Integer.MAX_VALUE ? 0 : counter + 1;
48        if (NAME_COUNTER.compareAndSet(counter, next)) {
49          break;
50        }
51      }
52      return store.getRegionInfo().getRegionNameAsString() + NAME_DELIMITER
53          + store.getFamily().getNameAsString() + NAME_DELIMITER + opName + NAME_DELIMITER + counter;
54    }
55  }