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.cassandra.io.sstable;
  
  import org.apache.cassandra.db.DecoratedKey;
  import org.apache.cassandra.db.rows.Row;
  import org.apache.cassandra.db.rows.Unfiltered;
  import org.apache.cassandra.io.sstable.format.SSTableReader;
  
  /**
   * Observer for events in the lifecycle of writing out an sstable.
   */
  public interface SSTableFlushObserver
  {
      /**
       * Called before writing any data to the sstable.
       */
      void begin();
  
      /**
       * Called when a new partition in being written to the sstable,
       * but before any cells are processed (see {@link #nextUnfilteredCluster(Unfiltered)}).
       *
       * @param key                the key being appended to SSTable.
       * @param keyPosition        the position of the key in the SSTable data file
       * @param keyPositionForSASI SSTable format specific key position for storage attached indexes, it can be
       *                           in data file or in some index file. It is the same position as returned by
       *                           {@link KeyReader#keyPositionForSecondaryIndex()} for the same format, and the same
       *                           position as expected by {@link SSTableReader#keyAtPositionFromSecondaryIndex(long)}.
       */
      void startPartition(DecoratedKey key, long keyPosition, long keyPositionForSASI);
  
      /**
       * Called when a static row is being written to the sstable. If static columns are present in the table, it is called
       * after {@link #startPartition(DecoratedKey, long, long)} and before any calls to {@link #nextUnfilteredCluster(Unfiltered)}.
       *
       * @param staticRow static row appended to the sstable, can be empty, may not be {@code null}
       */
      void staticRow(Row staticRow);
  
      /**
       * Called after an unfiltered is written to the sstable.
       *
       * Will be preceded by a call to {@link #startPartition(DecoratedKey, long, long)},
       * and the unfiltered should be assumed to belong to that partition.
       *
       * @param unfiltered the unfiltered being written to the SSTable
       */
      void nextUnfilteredCluster(Unfiltered unfiltered);
  
      /**
       * Called when all data is written to the file and it's ready to be finished up.
       */
      void complete();
  
      /**
       * Clean up resources on error. There should be no side effects if called multiple times.
       */
      @SuppressWarnings("unused")
      default void abort(Throwable accumulator) {}
  }