/**
    * 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;
  
  /**
   * Log cleaner that uses the timestamp of the wal to determine if it should
   * be deleted. By default they are allowed to live for 10 minutes.
   */
  @InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.CONFIG)
  public class TimeToLiveLogCleaner extends BaseLogCleanerDelegate {
    static final Log LOG = LogFactory.getLog(TimeToLiveLogCleaner.class.getName());
    // Configured time a log can be kept after it was closed
    private long ttl;
    private boolean stopped = false;
  
    @Override
    public boolean isLogDeletable(FileStatus fStat) {
      long currentTime = EnvironmentEdgeManager.currentTime();
      long time = fStat.getModificationTime();
      long life = currentTime - time;
      
      if (LOG.isTraceEnabled()) {
        LOG.trace("Log life:" + life + ", ttl:" + ttl + ", current:" + currentTime + ", from: "
            + time);
      }
      if (life < 0) {
        LOG.warn("Found a log (" + fStat.getPath() + ") newer than current time (" + currentTime
            + " < " + time + "), probably a clock skew");
        return false;
      }
      return life > ttl;
    }
  
    @Override
    public void setConf(Configuration conf) {
      super.setConf(conf);
      this.ttl = conf.getLong("hbase.master.logcleaner.ttl", 600000);
    }
  
  
    @Override
    public void stop(String why) {
      this.stopped = true;
    }
  
    @Override
    public boolean isStopped() {
      return this.stopped;
    }
  }