MessageAggregatorTransform (Nemo Project 0.4 API)

java.lang.Object
- org.apache.nemo.common.ir.vertex.transform.NoWatermarkEmitTransform<Pair<K,V>,O>
- - org.apache.nemo.common.ir.vertex.transform.MessageAggregatorTransform<K,V,O>

Type Parameters:

K - input key type.

V - input value type.

O - output type.

All Implemented Interfaces:

java.io.Serializable, Transform<Pair<K,V>,O>
```
public final class MessageAggregatorTransform<K,V,O>
extends NoWatermarkEmitTransform<Pair<K,V>,O>
```
A Transform that aggregates statistics generated by the MessageGeneratorTransform.

See Also:

Serialized Form

Nested Class Summary
- Nested classes/interfaces inherited from interface org.apache.nemo.common.ir.vertex.transform.Transform
  Transform.Context

Constructor Summary

Constructors
Constructor	Description
`MessageAggregatorTransform(MessageAggregatorVertex.InitialStateSupplier<O> initialStateSupplier, MessageAggregatorVertex.MessageAggregatorFunction<K,V,O> aggregator)`	Default constructor.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`close()`	Close the transform.
`void`	`onData(Pair<K,V> element)`	On data received.
`void`	`prepare(Transform.Context context, OutputCollector<O> oc)`	Prepare the transform.
`java.lang.String`	`toString()`

Methods inherited from class org.apache.nemo.common.ir.vertex.transform.NoWatermarkEmitTransform
onLatencymark, onWatermark

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - MessageAggregatorTransform
```
public MessageAggregatorTransform(MessageAggregatorVertex.InitialStateSupplier<O> initialStateSupplier,
                                  MessageAggregatorVertex.MessageAggregatorFunction<K,V,O> aggregator)
```
    Default constructor.
    
    Parameters:
    
    initialStateSupplier - to use.
    
    aggregator - to use.
- Method Detail
  - prepare
```
public void prepare(Transform.Context context,
                    OutputCollector<O> oc)
```
    Description copied from interface: Transform
    
    Prepare the transform.
    
    Parameters:
    
    context - of the transform.
    
    oc - that collects outputs.
  - onData
```
public void onData(Pair<K,V> element)
```
    Description copied from interface: Transform
    
    On data received.
    
    Parameters:
    
    element - data received.
  - close
```
public void close()
```
    Description copied from interface: Transform
    
    Close the transform.
  - toString
```
public java.lang.String toString()
```
    Overrides:
    
    toString in class java.lang.Object