org.apache.cassandra.db

Class Slice

java.lang.Object

org.apache.cassandra.db.Slice

public class Slice
extends java.lang.Object

A slice represents the selection of a range of rows.

A slice has a start and an end bound that are both (potentially full) clustering prefixes. A slice selects every rows whose clustering is bigger than the slice start prefix but smaller than the end prefix. Both start and end can be either inclusive or exclusive.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Slice.Serializer

Field Summary

Fields

Modifier and Type	Field and Description
static Slice	ALL The slice selecting all rows (of a given partition)
static Slice.Serializer	serializer

Method Summary

Modifier and Type	Method and Description
ClusteringBound	close(boolean reversed)
ClusteringBound	end()
boolean	equals(java.lang.Object other)
Slice	forPaging(ClusteringComparator comparator, Clustering lastReturned, boolean inclusive, boolean reversed) Returns a slice for continuing paging from the last returned clustering prefix.
int	hashCode()
boolean	includes(ClusteringComparator comparator, ClusteringPrefix bound) Returns whether a given clustering or bound is included in this slice.
boolean	intersects(ClusteringComparator comparator, java.util.List<java.nio.ByteBuffer> minClusteringValues, java.util.List<java.nio.ByteBuffer> maxClusteringValues) Given the per-clustering column minimum and maximum value a sstable contains, whether or not this slice potentially intersects that sstable or not.
boolean	isEmpty(ClusteringComparator comparator) Return whether the slice is empty.
static boolean	isEmpty(ClusteringComparator comparator, ClusteringBound start, ClusteringBound end) Return whether the slice formed by the two provided bound is empty or not.
static Slice	make(Clustering clustering)
static Slice	make(ClusteringBound start, ClusteringBound end)
static Slice	make(Clustering start, Clustering end)
static Slice	make(ClusteringComparator comparator, java.lang.Object... values)
ClusteringBound	open(boolean reversed)
ClusteringBound	start()
java.lang.String	toString(CFMetaData metadata)
java.lang.String	toString(ClusteringComparator comparator)

Methods inherited from class java.lang.Object

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

Field Detail

serializer

public static final Slice.Serializer serializer

ALL

public static final Slice ALL

The slice selecting all rows (of a given partition)

Method Detail

make

public static Slice make(ClusteringBound start,
                         ClusteringBound end)

make

public static Slice make(ClusteringComparator comparator,
                         java.lang.Object... values)

make

public static Slice make(Clustering clustering)

make

public static Slice make(Clustering start,
                         Clustering end)

start

public ClusteringBound start()

end

public ClusteringBound end()

open

public ClusteringBound open(boolean reversed)

close

public ClusteringBound close(boolean reversed)

isEmpty

public boolean isEmpty(ClusteringComparator comparator)

Return whether the slice is empty.

Parameters:

comparator - the comparator to compare the bounds.

Returns:

whether the slice formed is empty or not.

isEmpty

public static boolean isEmpty(ClusteringComparator comparator,
                              ClusteringBound start,
                              ClusteringBound end)

Return whether the slice formed by the two provided bound is empty or not.

Parameters:

comparator - the comparator to compare the bounds.

start - the start for the slice to consider. This must be a start bound.

end - the end for the slice to consider. This must be an end bound.

Returns:

whether the slice formed by start and end is empty or not.

includes

public boolean includes(ClusteringComparator comparator,
                        ClusteringPrefix bound)

Returns whether a given clustering or bound is included in this slice.

Parameters:

comparator - the comparator for the table this is a slice of.

bound - the bound to test inclusion of.

Returns:

whether bound is within the bounds of this slice.

forPaging

public Slice forPaging(ClusteringComparator comparator,
                       Clustering lastReturned,
                       boolean inclusive,
                       boolean reversed)

Returns a slice for continuing paging from the last returned clustering prefix.

Parameters:

comparator - the comparator for the table this is a filter for.

lastReturned - the last clustering that was returned for the query we are paging for. The resulting slices will be such that only results coming stricly after lastReturned are returned (where coming after means "greater than" if !reversed and "lesser than" otherwise).

inclusive - whether or not we want to include the lastReturned in the newly returned page of results.

reversed - whether the query we're paging for is reversed or not.

Returns:

a new slice that selects results coming after lastReturned, or null if paging the resulting slice selects nothing (i.e. if it originally selects nothing coming after lastReturned).

intersects

public boolean intersects(ClusteringComparator comparator,
                          java.util.List<java.nio.ByteBuffer> minClusteringValues,
                          java.util.List<java.nio.ByteBuffer> maxClusteringValues)

Given the per-clustering column minimum and maximum value a sstable contains, whether or not this slice potentially intersects that sstable or not.

Parameters:

comparator - the comparator for the table this is a slice of.

minClusteringValues - the smallest values for each clustering column that a sstable contains.

maxClusteringValues - the biggest values for each clustering column that a sstable contains.

Returns:

whether the slice might intersects with the sstable having minClusteringValues and maxClusteringValues.

toString

public java.lang.String toString(CFMetaData metadata)

toString

public java.lang.String toString(ClusteringComparator comparator)

equals

public boolean equals(java.lang.Object other)

Overrides:

equals in class java.lang.Object

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object