org.apache.cassandra.service.pager

Class AggregationQueryPager.AggregationPartitionIterator

java.lang.Object

org.apache.cassandra.service.pager.AggregationQueryPager.GroupByPartitionIterator

org.apache.cassandra.service.pager.AggregationQueryPager.AggregationPartitionIterator

All Implemented Interfaces:

java.lang.AutoCloseable, java.util.Iterator<RowIterator>, BasePartitionIterator<RowIterator>, PartitionIterator, CloseableIterator<RowIterator>

Enclosing class:

AggregationQueryPager

public final class AggregationQueryPager.AggregationPartitionIterator
extends AggregationQueryPager.GroupByPartitionIterator

PartitionIterator for queries without Group By but with aggregates.

For maintaining backward compatibility we are forced to use the DataLimits.CQLLimits instead of the DataLimits.CQLGroupByLimits. Due to that pages need to be fetched in a different way.

Constructor Summary

Constructors

Constructor and Description
AggregationPartitionIterator(int pageSize, ConsistencyLevel consistency, ClientState clientState, long queryStartNanoTime)
AggregationPartitionIterator(int pageSize, ReadExecutionController executionController, long queryStartNanoTime)

Method Summary

Modifier and Type	Method and Description
protected int	computeSubPageSize(int pageSize, int counted) Computes the size of the next sub-page to retrieve.
protected boolean	isDone(int pageSize, int counted)
protected QueryPager	updatePagerLimit(QueryPager pager, DataLimits limits, java.nio.ByteBuffer lastPartitionKey, Clustering<?> lastClustering) Updates the pager with the new limits if needed.

Methods inherited from class org.apache.cassandra.service.pager.AggregationQueryPager.GroupByPartitionIterator

close, hasNext, next

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.cassandra.utils.CloseableIterator

empty, wrap

Methods inherited from interface java.util.Iterator

forEachRemaining, remove

Constructor Detail

AggregationPartitionIterator

public AggregationPartitionIterator(int pageSize,
                                    ConsistencyLevel consistency,
                                    ClientState clientState,
                                    long queryStartNanoTime)

AggregationPartitionIterator

public AggregationPartitionIterator(int pageSize,
                                    ReadExecutionController executionController,
                                    long queryStartNanoTime)

Method Detail

updatePagerLimit

protected QueryPager updatePagerLimit(QueryPager pager,
                                      DataLimits limits,
                                      java.nio.ByteBuffer lastPartitionKey,
                                      Clustering<?> lastClustering)

Description copied from class: AggregationQueryPager.GroupByPartitionIterator

Updates the pager with the new limits if needed.

Overrides:

updatePagerLimit in class AggregationQueryPager.GroupByPartitionIterator

Parameters:

pager - the pager previoulsy used

limits - the DataLimits

lastPartitionKey - the partition key of the last row returned

lastClustering - the clustering of the last row returned

Returns:

the pager to use to query the next page of data

isDone

protected boolean isDone(int pageSize,
                         int counted)

Overrides:

isDone in class AggregationQueryPager.GroupByPartitionIterator

computeSubPageSize

protected int computeSubPageSize(int pageSize,
                                 int counted)

Description copied from class: AggregationQueryPager.GroupByPartitionIterator

Computes the size of the next sub-page to retrieve.

Overrides:

computeSubPageSize in class AggregationQueryPager.GroupByPartitionIterator

Parameters:

pageSize - the top-level page size

counted - the number of result returned so far by the previous sub-pages

Returns:

the size of the next sub-page to retrieve