content: /*
   * The Alluxio Open Foundation licenses this work under the Apache License, version 2.0
   * (the "License"). You may not use this work except in compliance with the License, which is
   * available at www.apache.org/licenses/LICENSE-2.0
   *
   * This software is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
   * either express or implied, as more fully set forth in the License.
   *
   * See the NOTICE file distributed with this work for information regarding copyright ownership.
   */
  
  package alluxio.master.file.async;
  
  import alluxio.AlluxioURI;
  import alluxio.exception.AccessControlException;
  import alluxio.exception.AlluxioException;
  import alluxio.exception.FileDoesNotExistException;
  import alluxio.exception.InvalidPathException;
  import alluxio.exception.status.UnavailableException;
  import alluxio.master.file.meta.FileSystemMasterView;
  import alluxio.wire.PersistFile;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.util.List;
  import javax.annotation.concurrent.ThreadSafe;
  
  /**
   * The handler that handles the scheduled async persist requests on files, and decides which worker
   * to take the persistence task. The handler carries the strategy of when and where to persist the
   * file.
   */
  public interface AsyncPersistHandler {
  
    /**
     * Factory for {@link AsyncPersistHandler}.
     */
    @ThreadSafe
    class Factory {
      public static final Logger LOG = LoggerFactory.getLogger(AsyncPersistHandler.Factory.class);
  
      private Factory() {} // prevent instantiation
  
      /**
       * Creates a new instance of {@link AsyncPersistHandler}.
       *
       * @param view {@link FileSystemMasterView} to pass to {@link AsyncPersistHandler}
       * @return the generated {@link AsyncPersistHandler}
       */
      public static AsyncPersistHandler create(FileSystemMasterView view) {
        return new DefaultAsyncPersistHandler(view);
      }
    }
  
    /**
     * Schedules a file for async persistence.
     *
     * @param path the path to the file
     */
    void scheduleAsyncPersistence(AlluxioURI path) throws AlluxioException, UnavailableException;
  
    /**
     * Polls the files for persistence on the given worker.
     *
     * @param workerId the id of the worker for persistence
     * @return the list of files for persistence
     * @throws FileDoesNotExistException if the file does not exist
     * @throws InvalidPathException if the path is invalid
     * @throws AccessControlException if permission checking fails
     */
    List<PersistFile> pollFilesToPersist(long workerId)
        throws FileDoesNotExistException, InvalidPathException, AccessControlException;
  }
  