org.apache.cassandra.utils.streamhist.TombstoneHistogram Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of cassandra-all Show documentation
Show all versions of cassandra-all Show documentation
The Apache Cassandra Project develops a highly scalable second-generation distributed database, bringing together Dynamo's fully distributed design and Bigtable's ColumnFamily-based data model.
/*
* 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 void forEach(HistogramDataConsumer 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
{
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;
}
}
}