org.apache.cassandra.db

Class DataRange.Paging

java.lang.Object

org.apache.cassandra.db.DataRange

org.apache.cassandra.db.DataRange.Paging

Enclosing class:

DataRange

public static class DataRange.Paging
extends DataRange

Specialized DataRange used for the paging case.

It uses the clustering of the last result of the previous page to restrict the filter on the first queried partition (the one for that last result) so it only fetch results that follow that last result. In other words, this makes sure this resume paging where we left off.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.cassandra.db.DataRange

DataRange.Paging, DataRange.Serializer

Field Summary

Fields inherited from class org.apache.cassandra.db.DataRange

clusteringIndexFilter, keyRange, serializer

Method Summary

Modifier and Type	Method and Description
ClusteringIndexFilter	clusteringIndexFilter(DecoratedKey key) The clustering index filter to use for the provided key.
DataRange	forSubRange(AbstractBounds<PartitionPosition> range) Returns a new DataRange equivalent to this one but restricted to the provided sub-range.
Clustering	getLastReturned()
boolean	isPaging() Whether the data range is for a paged request or not.
boolean	isUnrestricted() Whether this DataRange queries everything (has no restriction neither on the partition queried, nor within the queried partition).
java.lang.String	toString(CFMetaData metadata)

Methods inherited from class org.apache.cassandra.db.DataRange

allData, allData, appendKeyString, contains, forKeyRange, forPaging, forTokenRange, isNamesQuery, isWrapAround, keyRange, startKey, stopKey, toCQLString

Methods inherited from class java.lang.Object

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

Method Detail

clusteringIndexFilter

public ClusteringIndexFilter clusteringIndexFilter(DecoratedKey key)

Description copied from class: DataRange

The clustering index filter to use for the provided key.

This may or may not be the same filter for all keys (that is, paging range use a different filter for their start key).

Overrides:

clusteringIndexFilter in class DataRange

Parameters:

key - the partition key for which we want the clustering index filter.

Returns:

the clustering filter to use for key.

forSubRange

public DataRange forSubRange(AbstractBounds<PartitionPosition> range)

Description copied from class: DataRange

Returns a new DataRange equivalent to this one but restricted to the provided sub-range.

Overrides:

forSubRange in class DataRange

Parameters:

range - the sub-range to use for the newly returned data range. Note that assumes that range is a proper sub-range of the initial range but doesn't validate it. You should make sure to only provided sub-ranges however or this might throw off the paging case (see Paging.forSubRange()).

Returns:

a new DataRange using range as partition key range and the clustering index filter filter from this.

getLastReturned

public Clustering getLastReturned()

Returns:

the last Clustering that was returned (in the previous page)

isPaging

public boolean isPaging()

Description copied from class: DataRange

Whether the data range is for a paged request or not.

Overrides:

isPaging in class DataRange

Returns:

true if for paging, false otherwise

isUnrestricted

public boolean isUnrestricted()

Description copied from class: DataRange

Whether this DataRange queries everything (has no restriction neither on the partition queried, nor within the queried partition).

Overrides:

isUnrestricted in class DataRange

Returns:

Whether this DataRange queries everything.

toString

public java.lang.String toString(CFMetaData metadata)

Overrides:

toString in class DataRange