org.apache.drill.exec.physical.impl

Class ScanBatch.Mutator

java.lang.Object

org.apache.drill.exec.physical.impl.ScanBatch.Mutator

All Implemented Interfaces:

OutputMutator

Enclosing class:

ScanBatch

public static class ScanBatch.Mutator
extends Object
implements OutputMutator

Row set mutator implementation provided to record readers created by this scan batch. Made visible so that tests can create this mutator without also needing a ScanBatch instance. (This class is really independent of the ScanBatch, but resides here for historical reasons. This is, in turn, the only use of the generated vector readers in the vector package.)

Constructor Summary

Constructors

Constructor and Description
Mutator(OperatorContext oContext, BufferAllocator allocator, VectorContainer container)

Method Summary

Modifier and Type	Method and Description
<T extends ValueVector> T	addField(MaterializedField field, Class<T> clazz) Add a ValueVector for new (or existing) field.
void	allocate(int recordCount)
void	clear() Clear this mutator i.e.
Map<String,ValueVector>	fieldVectorMap()
CallBack	getCallBack()
DrillBuf	getManagedBuffer() Allows a scanner to request a set of managed block of memory.
Map<String,ValueVector>	implicitFieldVectorMap()
boolean	isNewSchema() Reports whether schema has changed (field was added or re-added) since last call to isNewSchema().

Methods inherited from class java.lang.Object

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

Constructor Detail

Mutator

public Mutator(OperatorContext oContext,
               BufferAllocator allocator,
               VectorContainer container)

Method Detail

fieldVectorMap

public Map<String,ValueVector> fieldVectorMap()

implicitFieldVectorMap

public Map<String,ValueVector> implicitFieldVectorMap()

addField

public <T extends ValueVector> T addField(MaterializedField field,
                                          Class<T> clazz)
                                   throws SchemaChangeException

Description copied from interface: OutputMutator

Add a ValueVector for new (or existing) field.

Specified by:

addField in interface OutputMutator

Parameters:

field - The specification of the newly desired vector.

clazz - The expected ValueVector class. Also allows strongly typed use of this interface.

Returns:

The existing or new ValueVector associated with the provided field.

Throws:

SchemaChangeException - If the addition of this field is incompatible with this OutputMutator's capabilities.

allocate

public void allocate(int recordCount)

Specified by:

allocate in interface OutputMutator

isNewSchema

public boolean isNewSchema()

Reports whether schema has changed (field was added or re-added) since last call to isNewSchema(). Returns true at first call.

Specified by:

isNewSchema in interface OutputMutator

Returns:

getManagedBuffer

public DrillBuf getManagedBuffer()

Description copied from interface: OutputMutator

Allows a scanner to request a set of managed block of memory.

Specified by:

getManagedBuffer in interface OutputMutator

Returns:

A DrillBuf that will be released at the end of the current query (and can be resized as desired during use).

getCallBack

public CallBack getCallBack()

Specified by:

getCallBack in interface OutputMutator

Returns:

the CallBack object for this mutator

clear

public void clear()

Description copied from interface: OutputMutator

Clear this mutator i.e. reset it to pristine condition

Specified by:

clear in interface OutputMutator