org.apache.cassandra.db.rows

Class EncodingStats

java.lang.Object

org.apache.cassandra.db.rows.EncodingStats

public class EncodingStats
extends java.lang.Object

Stats used for the encoding of the rows and tombstones of a given source.

Those stats are used to optimize the on-wire and on-disk storage of rows. More precisely, the minTimestamp, minLocalDeletionTime and minTTL stats are used to delta-encode those information for the sake of vint encoding.

Note that due to their use, those stats can suffer to be somewhat inaccurate (the more incurrate they are, the less effective the storage will be, but provided the stats are not completly wacky, this shouldn't have too huge an impact on performance) and in fact they will not always be accurate for reasons explained in SerializationHeader.make(org.apache.cassandra.config.CFMetaData, java.util.Collection<org.apache.cassandra.io.sstable.format.SSTableReader>).

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	EncodingStats.Collector
static class	EncodingStats.Serializer

Field Summary

Fields

Modifier and Type	Field and Description
int	minLocalDeletionTime
long	minTimestamp
int	minTTL
static EncodingStats	NO_STATS
static EncodingStats.Serializer	serializer

Constructor Summary

Constructors

Constructor and Description
EncodingStats(long minTimestamp, int minLocalDeletionTime, int minTTL)

Method Summary

Modifier and Type	Method and Description
boolean	equals(java.lang.Object o)
int	hashCode()
EncodingStats	mergeWith(EncodingStats that) Merge this stats with another one.
java.lang.String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

NO_STATS

public static final EncodingStats NO_STATS

serializer

public static final EncodingStats.Serializer serializer

minTimestamp

public final long minTimestamp

minLocalDeletionTime

public final int minLocalDeletionTime

minTTL

public final int minTTL

Constructor Detail

EncodingStats

public EncodingStats(long minTimestamp,
                     int minLocalDeletionTime,
                     int minTTL)

Method Detail

mergeWith

public EncodingStats mergeWith(EncodingStats that)

Merge this stats with another one.

The comments of SerializationHeader.make(org.apache.cassandra.config.CFMetaData, java.util.Collection<org.apache.cassandra.io.sstable.format.SSTableReader>) applies here too, i.e. the result of merging will be not totally accurate but we can live with that.

equals

public boolean equals(java.lang.Object o)

Overrides:

equals in class java.lang.Object

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object