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.utils.streamhist;
  
  import java.io.IOException;
  
  import org.apache.cassandra.db.TypeSizes;
  import org.apache.cassandra.db.rows.Cell;
  import org.apache.cassandra.io.ISerializer;
  import org.apache.cassandra.io.sstable.format.Version;
  import org.apache.cassandra.io.util.DataInputPlus;
  import org.apache.cassandra.io.util.DataOutputPlus;
  import org.apache.cassandra.utils.streamhist.StreamingTombstoneHistogramBuilder.DataHolder;
  
  /**
   * A snapshot or finished histrogram of tombstones for a sstable, as generated from {@link StreamingTombstoneHistogramBuilder}.
   */
  public class TombstoneHistogram
  {
      // Buffer with point-value pair
      private final DataHolder bin;
  
      /**
       * Creates a new histogram with max bin size of maxBinSize
       */
      TombstoneHistogram(DataHolder holder)
      {
          bin = new DataHolder(holder);
      }
  
      public static TombstoneHistogram createDefault()
      {
          return new TombstoneHistogram(new DataHolder(0, 1));
      }
  
      /**
       * Calculates estimated number of points in interval [-inf,b].
       *
       * @param b upper bound of a interval to calculate sum
       * @return estimated number of points in a interval [-inf,b].
       */
      public double sum(double b)
      {
          return bin.sum((int) b);
      }
  
      public int size()
      {
          return this.bin.size();
      }
  
      public <E extends Exception> void forEach(HistogramDataConsumer<E> histogramDataConsumer) throws E
      {
          this.bin.forEach(histogramDataConsumer);
      }
  
      public static HistogramSerializer getSerializer(Version version)
      {
          return version.hasUIntDeletionTime() ? HistogramSerializer.instance : LegacyHistogramSerializer.instance;
      }
  
      public static class HistogramSerializer implements ISerializer<TombstoneHistogram>
      {
          public static final HistogramSerializer instance = new HistogramSerializer();
  
          public void serialize(TombstoneHistogram histogram, DataOutputPlus out) throws IOException
          {
              final int size = histogram.size();
              final int maxBinSize = size; // we write this for legacy reasons
              out.writeInt(maxBinSize);
              out.writeInt(size);
              histogram.forEach((point, value) ->
                                {
                                    out.writeLong(point);
                                    out.writeInt(value);
                                });
          }
  
          public TombstoneHistogram deserialize(DataInputPlus in) throws IOException
          {
              in.readInt(); // max bin size
              int size = in.readInt();
              DataHolder dataHolder = new DataHolder(size, 1);
              for (int i = 0; i < size; i++)
              {
                  // Already serialized sstable metadata may contain negative deletion-time values (see CASSANDRA-14092).
                  // Just do a "safe cast" and it should be good. For safety, also do that for the 'value' (tombstone count).
                  long localDeletionTime = StreamingTombstoneHistogramBuilder.saturatingCastToMaxDeletionTime((long) in.readLong());
                  int count = StreamingTombstoneHistogramBuilder.saturatingCastToInt(in.readInt());
  
                  dataHolder.addValue(localDeletionTime, count);
              }
  
              return new TombstoneHistogram(dataHolder);
          }
  
          public long serializedSize(TombstoneHistogram histogram)
          {
              int maxBinSize = 0;
              long size = TypeSizes.sizeof(maxBinSize);
              final int histSize = histogram.size();
              size += TypeSizes.sizeof(histSize);
              // size of entries = size * (8(double) + 8(long))
              size += histSize * (8L + 8L);
              return size;
          }
      }
  
      @Override
      public boolean equals(Object o)
      {
          if (this == o)
              return true;
  
          if (!(o instanceof TombstoneHistogram))
              return false;
  
          TombstoneHistogram that = (TombstoneHistogram) o;
          return bin.equals(that.bin);
      }
  
      @Override
      public int hashCode()
      {
          return bin.hashCode();
      }
      
      public static class LegacyHistogramSerializer extends HistogramSerializer
      {
          public static final LegacyHistogramSerializer instance = new LegacyHistogramSerializer();
  
          public void serialize(TombstoneHistogram histogram, DataOutputPlus out) throws IOException
          {
              final int size = histogram.size();
              final int maxBinSize = size; // we write this for legacy reasons
              out.writeInt(maxBinSize);
              out.writeInt(size);
              histogram.forEach((point, value) ->
                                {
                                    out.writeDouble((double) point);
                                    out.writeLong((long) value);
                                });
          }
  
          public TombstoneHistogram deserialize(DataInputPlus in) throws IOException
          {
              in.readInt(); // max bin size
              int size = in.readInt();
              DataHolder dataHolder = new DataHolder(size, 1);
              for (int i = 0; i < size; i++)
              {
                  // Already serialized sstable metadata may contain negative deletion-time values (see CASSANDRA-14092).
                  // Just do a "safe cast" and it should be good. For safety, also do that for the 'value' (tombstone count).
                  int localDeletionTime = saturatingCastToLegacyMaxDeletionTime((long) in.readDouble());
                  int count = StreamingTombstoneHistogramBuilder.saturatingCastToInt(in.readLong());
  
                  dataHolder.addValue(localDeletionTime, count);
              }
  
              return new TombstoneHistogram(dataHolder);
          }
  
          public long serializedSize(TombstoneHistogram histogram)
          {
              int maxBinSize = 0;
              long size = TypeSizes.sizeof(maxBinSize);
              final int histSize = histogram.size();
              size += TypeSizes.sizeof(histSize);
              // size of entries = size * (8(double) + 8(long))
              size += histSize * (8L + 8L);
              return size;
          }
  
          private static int saturatingCastToLegacyMaxDeletionTime(long value)
          {
              return (value < 0L || value > Cell.MAX_DELETION_TIME_2038_LEGACY_CAP)
                     ? Cell.MAX_DELETION_TIME_2038_LEGACY_CAP
                     : (int) value;
          }
      }
  }
  