com.pervasive.datarush.operators

Interface CompositionIterator

public interface CompositionIterator

Interface to be implemented by iterative operators. This is the iteration "worker". This object is purposefully separated from iterator since the execute method will typically build internal state that needs to be stored in an instance variable and referenced in finalComposition(com.pervasive.datarush.operators.OperatorComposable).

Method Summary

Modifier and Type	Method and Description
void	execute(IterativeExecutionContext ctx) Executes this iterative operation.
void	finalComposition(OperatorComposable ctx) Called after execute is called.

Method Detail

execute

void execute(IterativeExecutionContext ctx)

Executes this iterative operation. From the context, the operation will typically create one or more subgraphs and execute them. Within the subgraphs, an iterator can reference its input ports (which automatically reference the staged dataset that was created by the framework for iteration).

Parameters:

ctx - context that provides a way to create subgraphs

finalComposition

void finalComposition(OperatorComposable ctx)

Called after execute is called. Implementations of this method must create connections to each of the IterativeOperator's output ports. Implementations also still have access to the IterativeOperator's input ports if needed. Generally iterators will produce a single (PMML) model in their execute method, so the implementation of this method will consist of the following:

    //wire the model that we generated in execute to the output port
    PutPMML put= ctx.add(new PutPMML(model));
    ctx.connect(put.getOutput(),output);
 

Parameters:

ctx - the context to which the iterator should add operators and connections