content: /*
   * 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.kafka.connect.runtime;
  
  import org.apache.kafka.common.utils.ThreadUtils;
  import org.apache.kafka.connect.errors.ConnectException;
  import org.apache.kafka.connect.source.SourceTask;
  import org.apache.kafka.connect.util.ConnectorTaskId;
  import org.apache.kafka.connect.util.LoggingContext;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.util.concurrent.CancellationException;
  import java.util.concurrent.ConcurrentHashMap;
  import java.util.concurrent.ConcurrentMap;
  import java.util.concurrent.ExecutionException;
  import java.util.concurrent.Executors;
  import java.util.concurrent.ScheduledExecutorService;
  import java.util.concurrent.ScheduledFuture;
  import java.util.concurrent.TimeUnit;
  
  /**
   * <p>
   * Manages offset commit scheduling and execution for {@link SourceTask}s.
   * </p>
   * <p>
   * Unlike sink tasks which directly manage their offset commits in the main poll() thread since
   * they drive the event loop and control (for all intents and purposes) the timeouts, source
   * tasks are at the whim of the connector and cannot be guaranteed to wake up on the necessary
   * schedule. Instead, this class tracks all the active tasks, their schedule for commits, and
   * ensures they are invoked in a timely fashion.
   * </p>
   */
  class SourceTaskOffsetCommitter {
      private static final Logger log = LoggerFactory.getLogger(SourceTaskOffsetCommitter.class);
  
      private final WorkerConfig config;
      private final ScheduledExecutorService commitExecutorService;
      private final ConcurrentMap<ConnectorTaskId, ScheduledFuture<?>> committers;
  
      // visible for testing
      SourceTaskOffsetCommitter(WorkerConfig config,
                                ScheduledExecutorService commitExecutorService,
                                ConcurrentMap<ConnectorTaskId, ScheduledFuture<?>> committers) {
          this.config = config;
          this.commitExecutorService = commitExecutorService;
          this.committers = committers;
      }
  
      public SourceTaskOffsetCommitter(WorkerConfig config) {
          this(config, Executors.newSingleThreadScheduledExecutor(ThreadUtils.createThreadFactory(
                  SourceTaskOffsetCommitter.class.getSimpleName() + "-%d", false)),
                  new ConcurrentHashMap<>());
      }
  
      public void close(long timeoutMs) {
          ThreadUtils.shutdownExecutorServiceQuietly(commitExecutorService, timeoutMs, TimeUnit.MILLISECONDS);
      }
  
      public void schedule(final ConnectorTaskId id, final WorkerSourceTask workerTask) {
          long commitIntervalMs = config.getLong(WorkerConfig.OFFSET_COMMIT_INTERVAL_MS_CONFIG);
          ScheduledFuture<?> commitFuture = commitExecutorService.scheduleWithFixedDelay(() -> {
              try (LoggingContext loggingContext = LoggingContext.forOffsets(id)) {
                  commit(workerTask);
              }
          }, commitIntervalMs, commitIntervalMs, TimeUnit.MILLISECONDS);
          committers.put(id, commitFuture);
      }
  
      public void remove(ConnectorTaskId id) {
          final ScheduledFuture<?> task = committers.remove(id);
          if (task == null)
              return;
  
          try (LoggingContext loggingContext = LoggingContext.forTask(id)) {
              task.cancel(false);
              if (!task.isDone())
                  task.get();
          } catch (CancellationException e) {
              // ignore
              log.trace("Offset commit thread was cancelled by another thread while removing connector task with id: {}", id);
          } catch (ExecutionException | InterruptedException e) {
              throw new ConnectException("Unexpected interruption in SourceTaskOffsetCommitter while removing task with id: " + id, e);
          }
      }
  
      // Visible for testing
      static void commit(WorkerSourceTask workerTask) {
          if (!workerTask.shouldCommitOffsets()) {
              log.trace("{} Skipping offset commit as there are no offsets that should be committed", workerTask);
              return;
          }
  
          log.debug("{} Committing offsets", workerTask);
          try {
              if (workerTask.commitOffsets()) {
                  return;
              }
              log.error("{} Failed to commit offsets", workerTask);
          } catch (Throwable t) {
              // We're very careful about exceptions here since any uncaught exceptions in the commit
              // thread would cause the fixed interval schedule on the ExecutorService to stop running
              // for that task
              log.error("{} Unhandled exception when committing: ", workerTask, t);
          }
      }
  }
  