Package org.apache.druid.query.scan

Class ConcatCursor

java.lang.Object

org.apache.druid.query.scan.ConcatCursor

All Implemented Interfaces:

Cursor

public class ConcatCursor
extends Object
implements Cursor

Combines multiple cursors and iterates over them. It skips over the empty cursors The DimensionSelector and ColumnValueSelector it generates hold the reference to the original object because the cursor might be advanced independently after extracting out the ColumnSelectorFactory like in FrameCursorUtils.cursorToFrames(org.apache.druid.segment.Cursor, org.apache.druid.frame.write.FrameWriterFactory). This ensures that the selectors always return the value pointed by the currentCursor.

Constructor Summary

Constructors

Constructor	Description
ConcatCursor(List<Cursor> cursors)

Method Summary

Modifier and Type	Method	Description
void	advance()
void	advanceUninterruptibly()
ColumnSelectorFactory	getColumnSelectorFactory()
org.joda.time.DateTime	getTime()
boolean	isDone()
boolean	isDoneOrInterrupted()
void	reset()

Methods inherited from class java.lang.Object

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

Constructor Detail

ConcatCursor

public ConcatCursor(List<Cursor> cursors)

Method Detail

getColumnSelectorFactory

public ColumnSelectorFactory getColumnSelectorFactory()

Specified by:

getColumnSelectorFactory in interface Cursor

getTime

public org.joda.time.DateTime getTime()

Specified by:

getTime in interface Cursor

advance

public void advance()

Specified by:

advance in interface Cursor

advanceUninterruptibly

public void advanceUninterruptibly()

Specified by:

advanceUninterruptibly in interface Cursor

isDone

public boolean isDone()

Specified by:

isDone in interface Cursor

isDoneOrInterrupted

public boolean isDoneOrInterrupted()

Specified by:

isDoneOrInterrupted in interface Cursor

reset

public void reset()

Specified by:

reset in interface Cursor