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;
  
  import java.util.Iterator;
  import java.util.List;
  import java.util.stream.Collectors;
  
  import com.google.common.annotations.VisibleForTesting;
  
  import org.apache.cassandra.db.partitions.PartitionUpdate;
  import org.apache.cassandra.exceptions.InvalidRequestException;
  
  import static org.apache.cassandra.db.IMutation.MAX_MUTATION_SIZE;
  
  public class MutationExceededMaxSizeException extends InvalidRequestException
  {
      public static final int PARTITION_MESSAGE_LIMIT = 1024;
  
      public final long mutationSize;
  
      MutationExceededMaxSizeException(IMutation mutation, int serializationVersion, long totalSize)
      {
          super(prepareMessage(mutation, serializationVersion, totalSize));
          this.mutationSize = totalSize;
      }
  
      private static String prepareMessage(IMutation mutation, int version, long totalSize)
      {
          List<String> topPartitions = mutation.getPartitionUpdates().stream()
                                               .sorted((upd1, upd2) ->
                                                       Long.compare(PartitionUpdate.serializer.serializedSize(upd2, version),
                                                                    PartitionUpdate.serializer.serializedSize(upd1, version)))
                                               .map(upd -> String.format("%s.%s",
                                                                         upd.metadata().name,
                                                                         upd.metadata().partitionKeyType.getString(upd.partitionKey().getKey())))
                                               .collect(Collectors.toList());
  
          String topKeys = makeTopKeysString(topPartitions, PARTITION_MESSAGE_LIMIT);
          return String.format("Rejected an oversized mutation (%d/%d) for keyspace: %s. Top keys are: %s",
                               totalSize,
                               MAX_MUTATION_SIZE,
                               mutation.getKeyspaceName(),
                               topKeys);
      }
  
      @VisibleForTesting
      static String makeTopKeysString(List<String> keys, int maxLength) {
          Iterator<String> iterator = keys.listIterator();
          StringBuilder stringBuilder = new StringBuilder();
          while (iterator.hasNext())
          {
              String key = iterator.next();
  
              if (stringBuilder.length() == 0)
              {
                  stringBuilder.append(key); //ensures atleast one key is added
                  iterator.remove();
              }
              else if (stringBuilder.length() + key.length() + 2 <= maxLength) // 2 for ", "
              {
                  stringBuilder.append(", ").append(key);
                  iterator.remove();
              }
              else
                  break;
          }
  
          if (keys.size() > 0)
              stringBuilder.append(" and ").append(keys.size()).append(" more.");
  
          return stringBuilder.toString();
      }
  }
  