Package org.apache.druid.frame.processor

Class MultiColumnSelectorFactory

java.lang.Object

org.apache.druid.frame.processor.MultiColumnSelectorFactory

All Implemented Interfaces:

Expr.InputBindingInspector, ColumnInspector, ColumnSelectorFactory

public class MultiColumnSelectorFactory
extends Object
implements ColumnSelectorFactory

A ColumnSelectorFactory that wraps multiple ColumnSelectorFactory and delegates to one of them at any given time. The identity of the delegated-to factory is changed by calling setCurrentFactory(int).

Constructor Summary

Constructors

Constructor	Description
MultiColumnSelectorFactory(List<Supplier<ColumnSelectorFactory>> factorySuppliers, RowSignature signature)

Method Summary

Modifier and Type	Method	Description
ColumnCapabilities	getColumnCapabilities(String column)	Returns capabilities of a particular column, if known.
ColumnValueSelector	makeColumnValueSelector(String columnName)	Returns ColumnValueSelector corresponding to the given column name, or NilColumnValueSelector if the column with such name is absent.
DimensionSelector	makeDimensionSelector(DimensionSpec dimensionSpec)
void	setCurrentFactory(int currentFactory)
MultiColumnSelectorFactory	withRowMemoryAndSignatureColumns()	Create a copy that includes FrameColumnSelectorFactory.ROW_SIGNATURE_COLUMN and FrameColumnSelectorFactory.ROW_MEMORY_COLUMN to potentially enable direct row memory copying.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.druid.segment.ColumnInspector

getType

Methods inherited from interface org.apache.druid.segment.ColumnSelectorFactory

getRowIdSupplier

Methods inherited from interface org.apache.druid.math.expr.Expr.InputBindingInspector

areNumeric, areNumeric, areSameTypes, areSameTypes, areScalar, areScalar, canVectorize, canVectorize

Constructor Details

MultiColumnSelectorFactory

public MultiColumnSelectorFactory(List<Supplier<ColumnSelectorFactory>> factorySuppliers,
 RowSignature signature)

Method Details

setCurrentFactory

public void setCurrentFactory(int currentFactory)

withRowMemoryAndSignatureColumns

public MultiColumnSelectorFactory withRowMemoryAndSignatureColumns()

Create a copy that includes FrameColumnSelectorFactory.ROW_SIGNATURE_COLUMN and FrameColumnSelectorFactory.ROW_MEMORY_COLUMN to potentially enable direct row memory copying. If these columns don't actually exist in the underlying column selector factories, they'll be ignored, so it's OK to use this method even if the columns may not exist.

makeDimensionSelector

public DimensionSelector makeDimensionSelector(DimensionSpec dimensionSpec)

Specified by:

makeDimensionSelector in interface ColumnSelectorFactory

makeColumnValueSelector

public ColumnValueSelector makeColumnValueSelector(String columnName)

Description copied from interface: ColumnSelectorFactory

Returns ColumnValueSelector corresponding to the given column name, or NilColumnValueSelector if the column with such name is absent.

Specified by:

makeColumnValueSelector in interface ColumnSelectorFactory

getColumnCapabilities

@Nullable
public ColumnCapabilities getColumnCapabilities(String column)

Description copied from interface: ColumnSelectorFactory

Returns capabilities of a particular column, if known. May be null if the column doesn't exist, or if the column does exist but the capabilities are unknown. The latter is possible with dynamically discovered columns.

Specified by:

getColumnCapabilities in interface ColumnInspector

Specified by:

getColumnCapabilities in interface ColumnSelectorFactory

Parameters:

column - column name

Returns:

capabilities, or null