org.apache.tez.runtime.api
Class MergedLogicalInput

java.lang.Object
  org.apache.tez.runtime.api.MergedLogicalInput

All Implemented Interfaces:

Input, LogicalInput

public abstract class MergedLogicalInput
extends Object
implements LogicalInput

A LogicalInput that is used to merge the data from multiple inputs and provide a single Reader to read that data. This Input is not initialized or closed. It is only expected to provide a merged view of the real inputs. It cannot send or receive events

Constructor Summary

MergedLogicalInput()

Method Summary

List<Event>	close() Closes the Input
List<Input>	getInputs()
void	handleEvents(List<Event> inputEvents) Handles user and system generated Events, which typically carry information such as an output being available on the previous vertex.
protected void	informInputReady() Used by the actual MergedInput to notify that it's ready for consumption.
void	initialize(List<Input> inputs)
List<Event>	initialize(TezInputContext inputContext) Initializes the Input.
abstract void	setConstituentInputIsReady(Input input) Used by the framework to inform the MergedInput that one of it's constituent Inputs is ready.
void	setInputReadyCallback(InputReadyCallback callback)
void	setNumPhysicalInputs(int numInputs) Sets the number of physical inputs that this LogicalInput will receive.
void	start() Start any processing that the Input may need to perform.

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.Input

getReader

Constructor Detail

MergedLogicalInput

public MergedLogicalInput()

Method Detail

initialize

public final void initialize(List<Input> inputs)

getInputs

public final List<Input> getInputs()

initialize

public final List<Event> initialize(TezInputContext inputContext)
                             throws Exception

Description copied from interface: Input

Initializes the Input.

Specified by:

initialize in interface Input

Parameters:

inputContext - the TezInputContext

Returns:

list of events that were generated during initialization

Throws:

Exception - if an error occurs

start

public final void start()
                 throws Exception

Description copied from interface: Input

Start any processing that the Input may need to perform. It is the responsibility of the Processor to start Inputs. This typically acts as a signal to Inputs to start any Processing that they may required. A blocking implementation of this method should not be used as a mechanism to determine when an Input is actually ready. This method may be invoked by the framework under certain circumstances, and as such requires the implementation to be non-blocking. Inputs must be written to handle multiple start invocations - typically honoring only the first one.

Specified by:

start in interface Input

Throws:

Exception

handleEvents

public final void handleEvents(List<Event> inputEvents)
                        throws Exception

Description copied from interface: Input

Handles user and system generated Events, which typically carry information such as an output being available on the previous vertex.

Specified by:

handleEvents in interface Input

Parameters:

inputEvents - the list of Events

Throws:

Exception

close

public final List<Event> close()
                        throws Exception

Description copied from interface: Input

Closes the Input

Specified by:

close in interface Input

Returns:

list of events that were generated during close

Throws:

Exception - if an error occurs

setNumPhysicalInputs

public final void setNumPhysicalInputs(int numInputs)

Description copied from interface: LogicalInput

Sets the number of physical inputs that this LogicalInput will receive. This will be called by the Tez framework before initializing the LogicalInput

Specified by:

setNumPhysicalInputs in interface LogicalInput

Parameters:

numInputs - the number of physical inputs.

setInputReadyCallback

public void setInputReadyCallback(InputReadyCallback callback)

informInputReady

protected final void informInputReady()

Used by the actual MergedInput to notify that it's ready for consumption. TBD eventually via the context.

setConstituentInputIsReady

public abstract void setConstituentInputIsReady(Input input)

Used by the framework to inform the MergedInput that one of it's constituent Inputs is ready.