Package org.apache.drill.exec.physical.resultSet.impl

Class RepeatedListState

java.lang.Object

org.apache.drill.exec.physical.resultSet.impl.ContainerState

org.apache.drill.exec.physical.resultSet.impl.RepeatedListState

All Implemented Interfaces:

RepeatedListWriter.ArrayListener

public class RepeatedListState
extends ContainerState
implements RepeatedListWriter.ArrayListener

Represents the internal state of a RepeatedList vector. The repeated list is wrapped in a repeated list "column state" that manages the column as a whole. The repeated list acts as a container which the RepeatedListState implements. At the vector level, we track the repeated list vector, but only perform operations on its associated offset vector.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	RepeatedListState.RepeatedListColumnState	Repeated list column state.
static class	RepeatedListState.RepeatedListVectorState	Track the repeated list vector.

Field Summary

Fields inherited from class org.apache.drill.exec.physical.resultSet.impl.ContainerState

loader, parentColumn, projectionSet, vectorCache

Constructor Summary

Constructors

Constructor	Description
RepeatedListState(org.apache.drill.exec.physical.resultSet.impl.LoaderInternals loader, ResultVectorCache vectorCache)

Method Summary

Modifier and Type	Method	Description
protected void	addColumn(ColumnState colState)
protected Collection<ColumnState>	columnStates()
int	innerCardinality()
protected boolean	isVersioned()	The repeated list vector does not support versioning of maps within the list.
AbstractObjectWriter	setChild(ArrayWriter array, MaterializedField field)
AbstractObjectWriter	setChild(ArrayWriter array, ColumnMetadata columnSchema)

Methods inherited from class org.apache.drill.exec.physical.resultSet.impl.ContainerState

addColumn, bindColumnState, close, harvestWithLookAhead, loader, projection, rollover, startBatch, updateCardinality, vectorCache

Methods inherited from class java.lang.Object

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

Constructor Details

RepeatedListState

public RepeatedListState(org.apache.drill.exec.physical.resultSet.impl.LoaderInternals loader,
 ResultVectorCache vectorCache)

Method Details

innerCardinality

public int innerCardinality()

Specified by:

innerCardinality in class ContainerState

addColumn

protected void addColumn(ColumnState colState)

Specified by:

addColumn in class ContainerState

columnStates

protected Collection<ColumnState> columnStates()

Specified by:

columnStates in class ContainerState

isVersioned

protected boolean isVersioned()

The repeated list vector does not support versioning of maps within the list. (That is, if a new field is added in the overflow row, it will appear in the output of the first batch.) The reasons for not versioning are simple: 1) repeated lists are a very obscure and low-priority area of Drill, and 2) given that background, the additional work of versioning is not worth the effort.

Specified by:

isVersioned in class ContainerState

Returns:

true if versioned

setChild

public AbstractObjectWriter setChild(ArrayWriter array,
 ColumnMetadata columnSchema)

Specified by:

setChild in interface RepeatedListWriter.ArrayListener

setChild

public AbstractObjectWriter setChild(ArrayWriter array,
 MaterializedField field)

Specified by:

setChild in interface RepeatedListWriter.ArrayListener