Package org.apache.druid.frame.segment.columnar

Class FrameVectorCursor

java.lang.Object

org.apache.druid.frame.segment.columnar.FrameVectorCursor

All Implemented Interfaces:

VectorCursor, VectorSizeInspector

public class FrameVectorCursor
extends Object
implements VectorCursor

A VectorCursor that is based on a Frame. This class is only used for columnar frames. It is not used for row-based frames.

Method Summary

Modifier and Type	Method	Description
void	advance()	Advances the cursor, skipping forward a number of rows equal to the current vector size.
VectorColumnSelectorFactory	getColumnSelectorFactory()	Returns a vectorized column selector factory.
int	getCurrentVectorSize()	Returns the current vector size for this cursor.
int	getMaxVectorSize()	Returns the maximum vector size for this cursor.
boolean	isDone()	Returns false if the cursor is readable, true if it has nothing left to read.
void	reset()	Resets the cursor back to its original state.

Methods inherited from class java.lang.Object

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

Method Details

getColumnSelectorFactory

public VectorColumnSelectorFactory getColumnSelectorFactory()

Description copied from interface: VectorCursor

Returns a vectorized column selector factory.

Specified by:

getColumnSelectorFactory in interface VectorCursor

advance

public void advance()

Description copied from interface: VectorCursor

Advances the cursor, skipping forward a number of rows equal to the current vector size.

Specified by:

advance in interface VectorCursor

isDone

public boolean isDone()

Description copied from interface: VectorCursor

Returns false if the cursor is readable, true if it has nothing left to read.

Specified by:

isDone in interface VectorCursor

reset

public void reset()

Description copied from interface: VectorCursor

Resets the cursor back to its original state. Useful for query engines that want to make multiple passes.

Specified by:

reset in interface VectorCursor

getMaxVectorSize

public int getMaxVectorSize()

Description copied from interface: VectorSizeInspector

Returns the maximum vector size for this cursor. It will not change for the lifetime of this cursor, and is generally used to allocate scratch arrays for later processing. Will always be greater than zero.

Specified by:

getMaxVectorSize in interface VectorSizeInspector

getCurrentVectorSize

public int getCurrentVectorSize()

Description copied from interface: VectorSizeInspector

Returns the current vector size for this cursor. Will never be larger than the max size returned by VectorSizeInspector.getMaxVectorSize().

Specified by:

getCurrentVectorSize in interface VectorSizeInspector