/**
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you under the Apache License, Version 2.0 (the
    * "License"); you may not use this file except in compliance
    * with the License.  You may obtain a copy of the License at
    *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.apache.hadoop.hbase.master.cleaner;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.fs.FileStatus;
  import org.apache.hadoop.hbase.HBaseInterfaceAudience;
  import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
  
  /**
   * HFile cleaner that uses the timestamp of the hfile to determine if it should be deleted. By
   * default they are allowed to live for {@value #DEFAULT_TTL}
   */
  @InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.CONFIG)
  public class TimeToLiveHFileCleaner extends BaseHFileCleanerDelegate {
  
    private static final Log LOG = LogFactory.getLog(TimeToLiveHFileCleaner.class.getName());
    public static final String TTL_CONF_KEY = "hbase.master.hfilecleaner.ttl";
    // default ttl = 5 minutes
    public static final long DEFAULT_TTL = 60000 * 5;
    // Configured time a hfile can be kept after it was moved to the archive
    private long ttl;
  
    @Override
    public void setConf(Configuration conf) {
      this.ttl = conf.getLong(TTL_CONF_KEY, DEFAULT_TTL);
      super.setConf(conf);
    }
  
    @Override
    public boolean isFileDeletable(FileStatus fStat) {
      long currentTime = EnvironmentEdgeManager.currentTime();
      long time = fStat.getModificationTime();
      long life = currentTime - time;
      if (LOG.isTraceEnabled()) {
        LOG.trace("HFile life:" + life + ", ttl:" + ttl + ", current:" + currentTime + ", from: "
            + time);
      }
      if (life < 0) {
        LOG.warn("Found a hfile (" + fStat.getPath() + ") newer than current time (" + currentTime
            + " < " + time + "), probably a clock skew");
        return false;
      }
      return life > ttl;
    }
  }