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.db.rows;
  
  import org.apache.cassandra.schema.ColumnMetadata;
  import org.apache.cassandra.db.*;
  
  /**
   * Interface that allows to act on the result of merging multiple rows.
   *
   * More precisely, given N rows and the result of merging them, one can call {@link Rows#diff(RowDiffListener, Row, Row...)}
   * with a {@code RowDiffListener} and that listener will be informed for each input row of the diff between
   * that input and merge row.
   */
  public interface RowDiffListener
  {
      /**
       * Called for the row primary key liveness info of input {@code i}.
       *
       * @param i the input row from which {@code original} is from.
       * @param clustering the clustering for the row that is merged.
       * @param merged the primary key liveness info of the merged row. Will be {@code null} if input {@code i} had
       * a {@code LivenessInfo}, but the merged result don't (i.e. the original info has been shadowed/deleted).
       * @param original the primary key liveness info of input {@code i}. May be {@code null} if input {@code i}
       * has not primary key liveness info (i.e. it has {@code LivenessInfo.NONE}) but the merged result has.
       */
      public void onPrimaryKeyLivenessInfo(int i, Clustering<?> clustering, LivenessInfo merged, LivenessInfo original);
  
      /**
       * Called for the row deletion of input {@code i}.
       *
       * @param i the input row from which {@code original} is from.
       * @param clustering the clustering for the row that is merged.
       * @param merged the deletion of the merged row. Will be {@code null} if input {@code i} had deletion
       * but the merged result doesn't (i.e. the deletion has been shadowed).
       * @param original the deletion of input {@code i}. May be {@code null} if input {@code i} had no deletion but the merged row has.
       */
      public void onDeletion(int i, Clustering<?> clustering, Row.Deletion merged, Row.Deletion original);
  
      /**
       * Called for every (non-live) complex deletion of any complex column present in either the merged row of input {@code i}.
       *
       * @param i the input row from which {@code original} is from.
       * @param clustering the clustering for the row that is merged.
       * @param column the column for which this is a complex deletion of.
       * @param merged the complex deletion of the merged row. Will be {@code null} if input {@code i} had a complex deletion
       * for {@code column} but the merged result doesn't (i.e. the deletion has been shadowed).
       * @param original the complex deletion of input {@code i} for column {@code column}. May be {@code null} if input {@code i}
       * had no complex deletion but the merged row has.
       */
      public void onComplexDeletion(int i, Clustering<?> clustering, ColumnMetadata column, DeletionTime merged, DeletionTime original);
  
      /**
       * Called for any cell that is either in the merged row or in input {@code i}.
       *
       * @param i the input row from which {@code original} is from.
       * @param clustering the clustering for the row that is merged.
       * @param merged the cell of the merged row. Will be {@code null} if input {@code i} had a cell but that cell is no present
       * in the merged result (it has been deleted/shadowed).
       * @param original the cell of input {@code i}. May be {@code null} if input {@code i} had cell corresponding to {@code merged}.
       */
      public void onCell(int i, Clustering<?> clustering, Cell<?> merged, Cell<?> original);
  }
  