org.apache.cassandra.db

Class ClusteringComparator

java.lang.Object

org.apache.cassandra.db.ClusteringComparator

All Implemented Interfaces:

java.util.Comparator<Clusterable>

public class ClusteringComparator
extends java.lang.Object
implements java.util.Comparator<Clusterable>

A comparator of clustering prefixes (or more generally of Clusterable}.

This is essentially just a composite comparator that the clustering values of the provided clustering prefixes in lexicographical order, with each component being compared based on the type of the clustering column this is a value of.

Constructor Summary

Constructors

Constructor and Description
ClusteringComparator(AbstractType<?>... clusteringTypes)
ClusteringComparator(java.util.List<AbstractType<?>> clusteringTypes)

Method Summary

Modifier and Type	Method and Description
int	compare(Clusterable c1, Clusterable c2)
int	compare(Clustering c1, Clustering c2)
int	compare(ClusteringPrefix c1, ClusteringPrefix c2)
int	compareComponent(int i, java.nio.ByteBuffer v1, java.nio.ByteBuffer v2)
boolean	equals(java.lang.Object o)
int	hashCode()
java.util.Comparator<IndexHelper.IndexInfo>	indexComparator(boolean reversed)
boolean	isCompatibleWith(ClusteringComparator previous) Returns whether this clustering comparator is compatible with the provided one, that is if the provided one can be safely replaced by this new one.
Clustering	make(java.lang.Object... values) Creates a row clustering based on the clustering values.
java.util.Comparator<Clusterable>	reversed()
java.util.Comparator<Row>	rowComparator() A comparator for rows.
int	size() The number of clustering columns for the table this is the comparator of.
AbstractType<?>	subtype(int i) Returns the type of the ith clustering column of the table.
java.util.List<AbstractType<?>>	subtypes() The "subtypes" of this clustering comparator, that is the types of the clustering columns for the table this is a comparator of.
java.lang.String	toString()
void	validate(ClusteringPrefix clustering) Validates the provided prefix for corrupted data.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Comparator

comparing, comparing, comparingDouble, comparingInt, comparingLong, naturalOrder, nullsFirst, nullsLast, reverseOrder, thenComparing, thenComparing, thenComparing, thenComparingDouble, thenComparingInt, thenComparingLong

Constructor Detail

ClusteringComparator

public ClusteringComparator(AbstractType<?>... clusteringTypes)

ClusteringComparator

public ClusteringComparator(java.util.List<AbstractType<?>> clusteringTypes)

Method Detail

size

public int size()

The number of clustering columns for the table this is the comparator of.

subtypes

public java.util.List<AbstractType<?>> subtypes()

The "subtypes" of this clustering comparator, that is the types of the clustering columns for the table this is a comparator of.

subtype

public AbstractType<?> subtype(int i)

Returns the type of the ith clustering column of the table.

make

public Clustering make(java.lang.Object... values)

Creates a row clustering based on the clustering values.

Every argument can either be a ByteBuffer, in which case it is used as-is, or a object corresponding to the type of the corresponding clustering column, in which case it will be converted to a byte buffer using the column type.

Parameters:

values - the values to use for the created clustering. There should be exactly size() values which must be either byte buffers or of the type the column expect.

Returns:

the newly created clustering.

compare

public int compare(Clusterable c1,
                   Clusterable c2)

Specified by:

compare in interface java.util.Comparator<Clusterable>

compare

public int compare(ClusteringPrefix c1,
                   ClusteringPrefix c2)

compare

public int compare(Clustering c1,
                   Clustering c2)

compareComponent

public int compareComponent(int i,
                            java.nio.ByteBuffer v1,
                            java.nio.ByteBuffer v2)

isCompatibleWith

public boolean isCompatibleWith(ClusteringComparator previous)

Returns whether this clustering comparator is compatible with the provided one, that is if the provided one can be safely replaced by this new one.

Parameters:

previous - the previous comparator that we want to replace and test compatibility with.

Returns:

whether previous can be safely replaced by this comparator.

validate

public void validate(ClusteringPrefix clustering)

Validates the provided prefix for corrupted data.

Parameters:

clustering - the clustering prefix to validate.

Throws:

MarshalException - if clustering contains some invalid data.

rowComparator

public java.util.Comparator<Row> rowComparator()

A comparator for rows. A Row is a Clusterable so ClusteringComparator can be used to compare rows directly, but when we know we deal with rows (and not Clusterable in general), this is a little faster because by knowing we compare Clustering objects, we know that 1) they all have the same size and 2) they all have the same kind.

indexComparator

public java.util.Comparator<IndexHelper.IndexInfo> indexComparator(boolean reversed)

reversed

public java.util.Comparator<Clusterable> reversed()

Specified by:

reversed in interface java.util.Comparator<Clusterable>

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

equals

public boolean equals(java.lang.Object o)

Specified by:

equals in interface java.util.Comparator<Clusterable>

Overrides:

equals in class java.lang.Object

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object