/*
 * 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.regionserver.handler;

import java.io.IOException;
import java.util.concurrent.atomic.AtomicInteger;
import org.apache.hadoop.hbase.Server;
import org.apache.hadoop.hbase.ServerName;
import org.apache.hadoop.hbase.SplitLogCounters;
import org.apache.hadoop.hbase.SplitLogTask;
import org.apache.hadoop.hbase.coordination.SplitLogWorkerCoordination;
import org.apache.hadoop.hbase.executor.EventHandler;
import org.apache.hadoop.hbase.executor.EventType;
import org.apache.hadoop.hbase.regionserver.SplitLogWorker.TaskExecutor;
import org.apache.hadoop.hbase.regionserver.SplitLogWorker.TaskExecutor.Status;
import org.apache.hadoop.hbase.util.CancelableProgressable;
import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
import org.apache.yetus.audience.InterfaceAudience;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Handles log splitting a wal Used by the zk-based distributed log splitting. Created by
 * ZKSplitLogWorkerCoordination.
 * @deprecated since 2.4.0 and in 3.0.0, to be removed in 4.0.0, replaced by procedure-based
 *             distributed WAL splitter, see SplitWALManager
 */
@Deprecated
@InterfaceAudience.Private
public class WALSplitterHandler extends EventHandler {
  private static final Logger LOG = LoggerFactory.getLogger(WALSplitterHandler.class);
  private final ServerName serverName;
  private final CancelableProgressable reporter;
  private final AtomicInteger inProgressTasks;
  private final TaskExecutor splitTaskExecutor;
  private final SplitLogWorkerCoordination.SplitTaskDetails splitTaskDetails;
  private final SplitLogWorkerCoordination coordination;

  public WALSplitterHandler(final Server server, SplitLogWorkerCoordination coordination,
    SplitLogWorkerCoordination.SplitTaskDetails splitDetails, CancelableProgressable reporter,
    AtomicInteger inProgressTasks, TaskExecutor splitTaskExecutor) {
    super(server, EventType.RS_LOG_REPLAY);
    this.splitTaskDetails = splitDetails;
    this.coordination = coordination;
    this.reporter = reporter;
    this.inProgressTasks = inProgressTasks;
    this.inProgressTasks.incrementAndGet();
    this.serverName = server.getServerName();
    this.splitTaskExecutor = splitTaskExecutor;
  }

  @Override
  public void process() throws IOException {
    long startTime = EnvironmentEdgeManager.currentTime();
    Status status = null;
    try {
      status = this.splitTaskExecutor.exec(splitTaskDetails.getWALFile(), reporter);
      switch (status) {
        case DONE:
          coordination.endTask(new SplitLogTask.Done(this.serverName),
            SplitLogCounters.tot_wkr_task_done, splitTaskDetails);
          break;
        case PREEMPTED:
          SplitLogCounters.tot_wkr_preempt_task.increment();
          LOG.warn("task execution preempted " + splitTaskDetails.getWALFile());
          break;
        case ERR:
          if (server != null && !server.isStopped()) {
            coordination.endTask(new SplitLogTask.Err(this.serverName),
              SplitLogCounters.tot_wkr_task_err, splitTaskDetails);
            break;
          }
          // if the RS is exiting then there is probably a tons of stuff
          // that can go wrong. Resign instead of signaling error.
          // $FALL-THROUGH$
        case RESIGNED:
          if (server != null && server.isStopped()) {
            LOG.info("task execution interrupted because worker is exiting "
              + splitTaskDetails.toString());
          }
          coordination.endTask(new SplitLogTask.Resigned(this.serverName),
            SplitLogCounters.tot_wkr_task_resigned, splitTaskDetails);
          break;
      }
    } finally {
      LOG.info("Worker " + serverName + " done with task " + splitTaskDetails.toString() + " in "
        + (EnvironmentEdgeManager.currentTime() - startTime) + "ms. Status = " + status);
      this.inProgressTasks.decrementAndGet();
    }
  }
}
