/*
 * 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.coprocessor;

import java.io.IOException;
import org.apache.hadoop.hbase.HBaseInterfaceAudience;
import org.apache.yetus.audience.InterfaceAudience;
import org.apache.yetus.audience.InterfaceStability;

/**
 * Coprocessors implement this interface to observe and mediate bulk load operations. <br>
 * <br>
 * <h3>Exception Handling</h3> For all functions, exception handling is done as follows:
 * <ul>
 * <li>Exceptions of type {@link IOException} are reported back to the client.</li>
 * <li>For any other kind of exception:
 * <ul>
 * <li>If the configuration {@link CoprocessorHost#ABORT_ON_ERROR_KEY} is set to true, then the
 * server aborts.</li>
 * <li>Otherwise, the coprocessor is removed from the server and
 * {@link org.apache.hadoop.hbase.DoNotRetryIOException} is returned to the client.</li>
 * </ul>
 * </li>
 * </ul>
 */
@InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.COPROC)
@InterfaceStability.Evolving
public interface BulkLoadObserver {
  /**
   * Called as part of the SecureBulkLoadEndpoint.prepareBulkLoad() RPC call. It can't bypass the
   * default action, e.g., ctx.bypass() won't have any effect. If you need to get the region or
   * table name, get it from the <code>ctx</code> as follows:
   * <code>ctx.getEnvironment().getRegion()</code>. Use getRegionInfo to fetch the encodedName and
   * use getDescriptor() to get the tableName.
   * @param ctx the environment to interact with the framework and master
   */
  default void prePrepareBulkLoad(ObserverContext<RegionCoprocessorEnvironment> ctx)
    throws IOException {
  }

  /**
   * Called as part of the SecureBulkLoadEndpoint.cleanupBulkLoad() RPC call. It can't bypass the
   * default action, e.g., ctx.bypass() won't have any effect. If you need to get the region or
   * table name, get it from the <code>ctx</code> as follows:
   * <code>ctx.getEnvironment().getRegion()</code>. Use getRegionInfo to fetch the encodedName and
   * use getDescriptor() to get the tableName.
   * @param ctx the environment to interact with the framework and master
   */
  default void preCleanupBulkLoad(ObserverContext<RegionCoprocessorEnvironment> ctx)
    throws IOException {
  }
}
