com.hp.hpl.jena.graph.query
Class Stage

java.lang.Object
  com.hp.hpl.jena.graph.query.Stage

Direct Known Subclasses:

ConstraintStage, InitialStage, PatternStageBase

public abstract class Stage
extends Object

a processing stage in the query pipeline. Each stage gets connected to its predecessor in the pipeline, and mangles the contents before handing them on to the next stage.

Author:

hedgehog

Field Summary

boolean

stillOpen

Constructor Summary

Stage()

Method Summary

void	close()
Stage	connectFrom(Stage s) connect this stage to its supplier; return this for chaining.
abstract Pipe	deliver(Pipe sink) execute the pipeline and pump the results into _sink_; this is asynchronous.
static Stage	initial(int count) construct a new initial stage for the pipeline
boolean	isClosed()

Methods inherited from class java.lang.Object

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

Field Detail

stillOpen

public volatile boolean stillOpen

Constructor Detail

Stage

public Stage()

Method Detail

initial

public static Stage initial(int count)

construct a new initial stage for the pipeline

connectFrom

public Stage connectFrom(Stage s)

connect this stage to its supplier; return this for chaining.

isClosed

public boolean isClosed()

close

public void close()

deliver

public abstract Pipe deliver(Pipe sink)

execute the pipeline and pump the results into _sink_; this is asynchronous. deliver that same _sink_ as our result. (This allows the sink to be created as the argument to _deliver_.)