/**
 * 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.hive.service.server;

import java.util.Map;

import org.apache.hadoop.hive.metastore.HiveMetaStore;
import org.apache.hadoop.hive.metastore.RawStore;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * A HiveServer2 thread used to construct new server threads.
 * In particular, this thread ensures an orderly cleanup,
 * when killed by its corresponding ExecutorService.
 */
public class ThreadWithGarbageCleanup extends Thread {
  private static final Logger LOG = LoggerFactory.getLogger(ThreadWithGarbageCleanup.class);

  Map<Long, RawStore> threadRawStoreMap =
      ThreadFactoryWithGarbageCleanup.getThreadRawStoreMap();

  public ThreadWithGarbageCleanup(Runnable runnable) {
    super(runnable);
  }

  /**
   * Add any Thread specific garbage cleanup code here.
   * Currently, it shuts down the RawStore object for this thread if it is not null.
   */
  @Override
  public void finalize() throws Throwable {
    cleanRawStore();
    super.finalize();
  }

  private void cleanRawStore() {
    Long threadId = this.getId();
    RawStore threadLocalRawStore = threadRawStoreMap.get(threadId);
    if (threadLocalRawStore != null) {
      LOG.debug("RawStore: " + threadLocalRawStore + ", for the thread: " +
          this.getName()  +  " will be closed now.");
      threadLocalRawStore.shutdown();
      threadRawStoreMap.remove(threadId);
    }
  }

  /**
   * Cache the ThreadLocal RawStore object. Called from the corresponding thread.
   */
  public void cacheThreadLocalRawStore() {
    Long threadId = this.getId();
    RawStore threadLocalRawStore = HiveMetaStore.HMSHandler.getRawStore();
    if (threadLocalRawStore != null && !threadRawStoreMap.containsKey(threadId)) {
      LOG.debug("Adding RawStore: " + threadLocalRawStore + ", for the thread: " +
          this.getName() + " to threadRawStoreMap for future cleanup.");
      threadRawStoreMap.put(threadId, threadLocalRawStore);
    }
  }
}
