org.apache.drill.exec.physical.impl.scan.project

Class NoOpMetadataManager

java.lang.Object

org.apache.drill.exec.physical.impl.scan.project.NoOpMetadataManager

All Implemented Interfaces:

MetadataManager

public class NoOpMetadataManager
extends Object
implements MetadataManager

Do-nothing implementation of the metadata manager. Allows the metadata manager to be optional without needing an if-statement on every access.

Constructor Summary

Constructors

Constructor and Description
NoOpMetadataManager()

Method Summary

Modifier and Type	Method and Description
void	bind(ResultVectorCache vectorCache)
void	close() Event indicating the end of a scan.
void	define() Define (materialize) the columns which this manager represents.
void	endFile() Event indicating the end of a file (or other data source.)
void	load(int rowCount) Load data into the custom columns, if needed (such as for null or implicit columns.)
ScanLevelProjection.ScanProjectionParser	projectionParser()
ReaderLevelProjection.ReaderProjectionResolver	resolver()

Methods inherited from class java.lang.Object

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

Constructor Detail

NoOpMetadataManager

public NoOpMetadataManager()

Method Detail

bind

public void bind(ResultVectorCache vectorCache)

Specified by:

bind in interface MetadataManager

projectionParser

public ScanLevelProjection.ScanProjectionParser projectionParser()

Specified by:

projectionParser in interface MetadataManager

resolver

public ReaderLevelProjection.ReaderProjectionResolver resolver()

Specified by:

resolver in interface MetadataManager

define

public void define()

Description copied from interface: MetadataManager

Define (materialize) the columns which this manager represents.

Specified by:

define in interface MetadataManager

load

public void load(int rowCount)

Description copied from interface: MetadataManager

Load data into the custom columns, if needed (such as for null or implicit columns.)

Specified by:

load in interface MetadataManager

Parameters:

rowCount - number of rows read into a batch.

endFile

public void endFile()

Description copied from interface: MetadataManager

Event indicating the end of a file (or other data source.)

Specified by:

endFile in interface MetadataManager

close

public void close()

Description copied from interface: MetadataManager

Event indicating the end of a scan.

Specified by:

close in interface MetadataManager