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.compaction.writers;
  
  import java.util.Set;
  
  import org.apache.cassandra.db.ColumnFamilyStore;
  import org.apache.cassandra.db.DecoratedKey;
  import org.apache.cassandra.db.Directories;
  import org.apache.cassandra.db.compaction.OperationType;
  import org.apache.cassandra.db.lifecycle.ILifecycleTransaction;
  import org.apache.cassandra.io.sstable.format.SSTableReader;
  
  public class MaxSSTableSizeWriter extends CompactionAwareWriter
  {
      private final long maxSSTableSize;
      private final int level;
      private final long estimatedSSTables;
  
      public MaxSSTableSizeWriter(ColumnFamilyStore cfs,
                                  Directories directories,
                                  ILifecycleTransaction txn,
                                  Set<SSTableReader> nonExpiredSSTables,
                                  long maxSSTableSize,
                                  int level)
      {
          this(cfs, directories, txn, nonExpiredSSTables, maxSSTableSize, level, false);
      }
  
      public MaxSSTableSizeWriter(ColumnFamilyStore cfs,
                                  Directories directories,
                                  ILifecycleTransaction txn,
                                  Set<SSTableReader> nonExpiredSSTables,
                                  long maxSSTableSize,
                                  int level,
                                  boolean keepOriginals)
      {
          super(cfs, directories, txn, nonExpiredSSTables, keepOriginals);
          this.level = level;
          this.maxSSTableSize = maxSSTableSize;
  
          long totalSize = getTotalWriteSize(nonExpiredSSTables, estimatedTotalKeys, cfs, txn.opType());
          estimatedSSTables = Math.max(1, totalSize / maxSSTableSize);
      }
  
      /**
       * Gets the estimated total amount of data to write during compaction
       */
      private static long getTotalWriteSize(Iterable<SSTableReader> nonExpiredSSTables, long estimatedTotalKeys, ColumnFamilyStore cfs, OperationType compactionType)
      {
          long estimatedKeysBeforeCompaction = 0;
          for (SSTableReader sstable : nonExpiredSSTables)
              estimatedKeysBeforeCompaction += sstable.estimatedKeys();
          estimatedKeysBeforeCompaction = Math.max(1, estimatedKeysBeforeCompaction);
          double estimatedCompactionRatio = (double) estimatedTotalKeys / estimatedKeysBeforeCompaction;
  
          return Math.round(estimatedCompactionRatio * cfs.getExpectedCompactedFileSize(nonExpiredSSTables, compactionType));
      }
  
      @Override
      protected boolean shouldSwitchWriterInCurrentLocation(DecoratedKey key)
      {
          return sstableWriter.currentWriter().getEstimatedOnDiskBytesWritten() > maxSSTableSize;
      }
  
      protected int sstableLevel()
      {
          return level;
      }
  
      protected long sstableKeyCount()
      {
          return estimatedTotalKeys / estimatedSSTables;
      }
  
      @Override
      protected long getExpectedWriteSize()
      {
          return Math.min(maxSSTableSize, super.getExpectedWriteSize());
      }
  }
  