Transform (Nemo Project 0.4 API)

Type Parameters:

I - input type.

O - output type.

All Superinterfaces:

java.io.Serializable

All Known Implementing Classes:

AbstractDoFnTransform, CombineFnFinalTransform, CombineFnPartialTransform, CreateViewTransform, DoFnTransform, EmptyComponents.EmptyTransform, FlattenTransform, GBKTransform, GroupByKeyTransform, LatencymarkEmitTransform, MessageAggregatorTransform, MessageGeneratorTransform, NoWatermarkEmitTransform, PushBackDoFnTransform, SideInputTransform, SignalTransform, StreamTransform, WindowFnTransform
```
public interface Transform<I,O>
extends java.io.Serializable
```
Interface for specifying 'What' to do with data. It is to be implemented in the compiler frontend, possibly for every operator in a dataflow language. 'How' and 'When' to do with its input/output data are up to the runtime.

Nested Class Summary

Nested Classes
Modifier and Type Interface Description

static interface Transform.Context
Context of the transform.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`void`	`close()`	Close the transform.
`void`	`onData(I element)`	On data received.
`void`	`onLatencymark(LatencyMark latencymark)`	On latencymark received.
`void`	`onWatermark(Watermark watermark)`	On watermark received.
`void`	`prepare(Transform.Context context, OutputCollector<O> outputCollector)`	Prepare the transform.

- Method Detail
  - prepare
```
void prepare(Transform.Context context,
             OutputCollector<O> outputCollector)
```
    Prepare the transform.
    
    Parameters:
    
    context - of the transform.
    
    outputCollector - that collects outputs.
  - onData
```
void onData(I element)
```
    On data received.
    
    Parameters:
    
    element - data received.
  - onWatermark
```
void onWatermark(Watermark watermark)
```
    On watermark received. This method should be called for the minimum watermark among input streams (input watermark). Transform may emit collected data after receiving watermarks.
    
    Parameters:
    
    watermark - watermark
  - onLatencymark
```
void onLatencymark(LatencyMark latencymark)
```
    On latencymark received.
    
    Parameters:
    
    latencymark - latencymark.
  - close
```
void close()
```
    Close the transform.