Package org.apache.cassandra.db.transform

Class Transformation<I extends BaseRowIterator<?>>

java.lang.Object

org.apache.cassandra.db.transform.Transformation<I>

Direct Known Subclasses:

DuplicateRowChecker, EmptyPartitionsDiscarder, EnsureOnHeap, Filter, PurgeFunction, RTBoundCloser, RTBoundValidator, ShortReadPartitionsProtection, StoppingTransformation, TopPartitionTracker.TombstoneCounter, WithOnlyQueriedData

public abstract class Transformation<I extends BaseRowIterator<?>>
extends java.lang.Object

We have a single common superclass for all Transformations to make implementation efficient. we have a shared stack for all transformations, and can share the same transformation across partition and row iterators, reducing garbage. Internal code is also simplified by always having a basic no-op implementation to invoke. Only the necessary methods need be overridden. Early termination is provided by invoking the method's stop or stopInPartition methods, rather than having their own abstract method to invoke, as this is both more efficient and simpler to reason about.

Constructor Summary

Constructors

Constructor	Description
Transformation()

Method Summary

Modifier and Type	Method	Description
static PartitionIterator	apply(PartitionIterator iterator, Transformation<? super RowIterator> transformation)
static UnfilteredPartitionIterator	apply(UnfilteredPartitionIterator iterator, Transformation<? super UnfilteredRowIterator> transformation)
static RowIterator	apply(RowIterator iterator, Transformation<?> transformation)
static UnfilteredRowIterator	apply(UnfilteredRowIterator iterator, Transformation<?> transformation)
protected DeletionTime	applyToDeletion(DeletionTime deletionTime)	Applied to the partition-level deletion of any rows iterator.
protected RangeTombstoneMarker	applyToMarker(RangeTombstoneMarker marker)	Applied to any RTM we encounter in a rows/unfiltered iterator
protected I	applyToPartition(I partition)	Applied to any rows iterator (partition) we encounter in a partitions iterator
protected RegularAndStaticColumns	applyToPartitionColumns(RegularAndStaticColumns columns)	Applied to the PartitionColumns of any rows iterator.
protected DecoratedKey	applyToPartitionKey(DecoratedKey key)	Applied to the partition key of any rows/unfiltered iterator we are applied to
protected Row	applyToRow(Row row)	Applied to any row we encounter in a rows iterator
protected Row	applyToStatic(Row row)	Applied to the static row of any rows iterator.
protected void	onClose()	Run on the close of any (logical) partitions iterator this function was applied to We stipulate logical, because if applied to a transformed iterator the lifetime of the iterator object may be longer than the lifetime of the "logical" iterator it was applied to; if the iterator is refilled with MoreContents, for instance, the iterator may outlive this function
protected void	onPartitionClose()	Run on the close of any (logical) rows iterator this function was applied to We stipulate logical, because if applied to a transformed iterator the lifetime of the iterator object may be longer than the lifetime of the "logical" iterator it was applied to; if the iterator is refilled with MoreContents, for instance, the iterator may outlive this function

Methods inherited from class java.lang.Object

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

Constructor Detail

Transformation

public Transformation()

Method Detail

onClose

protected void onClose()

Run on the close of any (logical) partitions iterator this function was applied to We stipulate logical, because if applied to a transformed iterator the lifetime of the iterator object may be longer than the lifetime of the "logical" iterator it was applied to; if the iterator is refilled with MoreContents, for instance, the iterator may outlive this function

onPartitionClose

protected void onPartitionClose()

Run on the close of any (logical) rows iterator this function was applied to We stipulate logical, because if applied to a transformed iterator the lifetime of the iterator object may be longer than the lifetime of the "logical" iterator it was applied to; if the iterator is refilled with MoreContents, for instance, the iterator may outlive this function

applyToPartition

protected I applyToPartition(I partition)

Applied to any rows iterator (partition) we encounter in a partitions iterator

applyToRow

protected Row applyToRow(Row row)

Applied to any row we encounter in a rows iterator

applyToMarker

protected RangeTombstoneMarker applyToMarker(RangeTombstoneMarker marker)

Applied to any RTM we encounter in a rows/unfiltered iterator

applyToPartitionKey

protected DecoratedKey applyToPartitionKey(DecoratedKey key)

Applied to the partition key of any rows/unfiltered iterator we are applied to

applyToStatic

protected Row applyToStatic(Row row)

Applied to the static row of any rows iterator. NOTE that this is only applied to the first iterator in any sequence of iterators filled by a MoreContents; the static data for such iterators is all expected to be equal

applyToDeletion

protected DeletionTime applyToDeletion(DeletionTime deletionTime)

Applied to the partition-level deletion of any rows iterator. NOTE that this is only applied to the first iterator in any sequence of iterators filled by a MoreContents; the static data for such iterators is all expected to be equal

applyToPartitionColumns

protected RegularAndStaticColumns applyToPartitionColumns(RegularAndStaticColumns columns)

Applied to the PartitionColumns of any rows iterator. NOTE: same remark than for applyToDeletion: it is only applied to the first iterator in a sequence of iterators filled by MoreContents.

apply

public static UnfilteredPartitionIterator apply(UnfilteredPartitionIterator iterator,
                                                Transformation<? super UnfilteredRowIterator> transformation)

apply

public static PartitionIterator apply(PartitionIterator iterator,
                                      Transformation<? super RowIterator> transformation)

apply

public static UnfilteredRowIterator apply(UnfilteredRowIterator iterator,
                                          Transformation<?> transformation)

apply

public static RowIterator apply(RowIterator iterator,
                                Transformation<?> transformation)