/*
 * 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.hudi.sink.partitioner.index;

import org.apache.hudi.sink.event.Correspondent;

import org.apache.flink.metrics.MetricGroup;

import java.io.Closeable;

/**
 * An interface that provides common lifecycle hooks for index backends.
 */
public interface IndexBackend extends Closeable {

  /**
   * Listener method called when the bucket assign operator finishes the checkpoint with {@code checkpointId}.
   *
   * @param checkpointId checkpoint id.
   */
  default void onCheckpoint(long checkpointId) {
    // do nothing.
  }

  /**
   * Listener method called when the bucket assign operator receives a notify checkpoint complete event.
   *
   * @param correspondent         The Correspondent used to get inflight instants from the coordinator.
   * @param completedCheckpointId The latest completed checkpoint id
   */
  default void onCheckpointComplete(Correspondent correspondent, long completedCheckpointId) {
    // do nothing.
  }

  /**
   * Registers metrics for this backend.
   *
   * @param metricGroup flink metric group
   */
  default void registerMetrics(MetricGroup metricGroup) {
    // do nothing.
  }
}
