org.apache.tez.runtime.api

Class AbstractLogicalOutput

java.lang.Object

org.apache.tez.runtime.api.AbstractLogicalOutput

All Implemented Interfaces:

LogicalOutput, LogicalOutputFrameworkInterface, Output, OutputFrameworkInterface

@InterfaceAudience.Public
public abstract class AbstractLogicalOutput
extends Object
implements LogicalOutput, LogicalOutputFrameworkInterface

An abstract class which should be the base class for all implementations of LogicalOutput. This class implements the framework facing as well as user facing methods which need to be implemented by all LogicalOutputs. This includes default implementations of a new method for convenience.

Constructor Summary

Constructors

Constructor and Description
AbstractLogicalOutput(OutputContext outputContext, int numPhysicalOutputs) Constructor an instance of the LogicalOutput.

Method Summary

Modifier and Type	Method and Description
OutputContext	getContext() Return the OutputContext for this specific instance of the LogicalOutput
int	getNumPhysicalOutputs() Get the number of physical outputs that this LogicalOutput is expected to generate.
abstract List<Event>	initialize() Initializes the Output

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.tez.runtime.api.Output

getWriter, start

Methods inherited from interface org.apache.tez.runtime.api.OutputFrameworkInterface

close, handleEvents

Constructor Detail

AbstractLogicalOutput

public AbstractLogicalOutput(OutputContext outputContext,
                             int numPhysicalOutputs)

Constructor an instance of the LogicalOutput. Classes extending this one to create a LogicalOutput, must provide the same constructor so that Tez can create an instance of the class at runtime.

Parameters:

outputContext - the OutputContext which provides the Output with context information within the running task.

numPhysicalOutputs - the number of physical outputs that the logical output will generate. This is typically determined by Edge Routing.

Method Detail

initialize

public abstract List<Event> initialize()
                                throws Exception

Description copied from interface: OutputFrameworkInterface

Initializes the Output

Specified by:

initialize in interface OutputFrameworkInterface

Returns:

list of events that were generated during initialization

Throws:

Exception - if an error occurs

getNumPhysicalOutputs

public final int getNumPhysicalOutputs()

Get the number of physical outputs that this LogicalOutput is expected to generate. This is typically determined by Edge routing, and number of downstream tasks

Returns:

the number of physical outputs

getContext

public final OutputContext getContext()

Return the OutputContext for this specific instance of the LogicalOutput

Returns:

the OutputContext for the output