hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/FlushPolicy.java

   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;
  19
  20 import java.util.Collection;
  21
  22 import org.apache.hadoop.conf.Configured;
  23 import org.apache.yetus.audience.InterfaceAudience;
  24
  25 /**
  26  * A flush policy determines the stores that need to be flushed when flushing a region.
  27  */
  28 @InterfaceAudience.Private
  29 public abstract class FlushPolicy extends Configured {
  30
  31   /**
  32    * The region configured for this flush policy.
  33    */
  34   protected HRegion region;
  35
  36   /**
  37    * Upon construction, this method will be called with the region to be governed. It will be called
  38    * once and only once.
  39    */
  40   protected void configureForRegion(HRegion region) {
  41     this.region = region;
  42   }
  43
  44   /**
  45    * @return the stores need to be flushed.
  46    */
  47   public abstract Collection<HStore> selectStoresToFlush();
  48
  49 }