alluxio-master-2.x/underfs/hdfs/src/main/java/alluxio/underfs/hdfs/HdfsActiveSyncProvider.java
/*
 * 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.underfs.hdfs;

import alluxio.AlluxioURI;
import alluxio.SyncInfo;

import java.io.IOException;

/**
 * Interface for providing HDFS ActiveSync.
 */
public interface HdfsActiveSyncProvider {
  /**
   * Get Active SyncInfo from the sync provider.
   *
   * @return SyncInfo a syncInfo containing information about what to sync and how to sync
   */
  SyncInfo getActivitySyncInfo();

  /**
   * start polling thread.
   *
   * @param txId transaction id to start monitoring
   * @return true if polling thread started successfully
   */
  boolean startPolling(long txId) throws IOException;

  /**
   * stop polling thread.
   *
   * @return true if polling thread stopped successfully
   */
  boolean stopPolling();

  /**
   * start syncing on a ufs uri.
   *
   * @param ufsUri the ufs uri to monitor
   */
  void startSync(AlluxioURI ufsUri);

  /**
   * stop syncing on a ufs uri.
   *
   * @param ufsUri the ufs uri to stop monitoring
   */
  void stopSync(AlluxioURI ufsUri);
}
