com.faunos.util.net
Class AsynchStagelet

java.lang.Object
  com.faunos.util.net.AsynchStagelet

All Implemented Interfaces:

Handlet, Stagelet

public abstract class AsynchStagelet
extends Object
implements Stagelet

A skeletal implementation of an asynchronous stagelet. An instance starts out in the IoState.PROCESSING state. Later, when the task is completed, a stagelet representing the completion of the task is pushed onto the stack.

Author:

Babak Farhang

See Also:

init(HandletContext), nextStage()

Field Summary

protected StageletStack

stack

Constructor Summary

protected

AsynchStagelet(StageletStack stack)

Method Summary

void	discard() Does nothing.
IoState	init(HandletContext context) Asynchronously invokes the nextStage() method, pushes the returned stagelet onto the stack, initializes it, and notifies the container that it is done processing.
protected abstract Stagelet	nextStage() Returns the next stage which will be pushed onto the stack.
IoState	read(ScatteringByteChannel in) Not implemented.
IoState	state() Returns DONE, if unwound; PROCESSING, otherwise.
IoState	unwind(IoState preState) Sets the state to DONE.
IoState	write(GatheringByteChannel out) Not implemented.

Methods inherited from class java.lang.Object

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

Field Detail

stack

protected final StageletStack stack

Constructor Detail

AsynchStagelet

protected AsynchStagelet(StageletStack stack)

Method Detail

unwind

public IoState unwind(IoState preState)

Sets the state to DONE.

Specified by:

unwind in interface Stagelet

Parameters:

preState - the state of the previous stage prior to its flipping to DONE

Returns:

DONE

discard

public void discard()

Does nothing.

Specified by:

discard in interface Handlet

init

public IoState init(HandletContext context)

Asynchronously invokes the nextStage() method, pushes the returned stagelet onto the stack, initializes it, and notifies the container that it is done processing.

This method returns immediately.

Specified by:

init in interface Handlet

Parameters:

context - the context supplied by the instance's container (e.g. server

Returns:

IoState.PROCESSING

read

public IoState read(ScatteringByteChannel in)
             throws IOException

Not implemented.

Specified by:

read in interface Handlet

Throws:

UnsupportedOperationException

IOException

See Also:

state()

state

public IoState state()

Returns DONE, if unwound; PROCESSING, otherwise.

Specified by:

state in interface Handlet

write

public IoState write(GatheringByteChannel out)
              throws IOException

Not implemented.

Specified by:

write in interface Handlet

Throws:

UnsupportedOperationException

IOException

See Also:

state()

nextStage

protected abstract Stagelet nextStage()

Returns the next stage which will be pushed onto the stack. This method is invoked asynchronously and the returned stagelet is the end result of that execution. The returned stagelet will be in either of the IoState.READING or IoState.WRITING states.

See Also:

init(HandletContext)