Enum Class DefaultPipelineController.PipelineState

java.lang.Object

java.lang.Enum<DefaultPipelineController.PipelineState>

io.aleph0.yap.core.pipeline.DefaultPipelineController.PipelineState

All Implemented Interfaces:

Serializable, Comparable<DefaultPipelineController.PipelineState>, Constable

Enclosing class:

DefaultPipelineController

public static enum DefaultPipelineController.PipelineState
extends Enum<DefaultPipelineController.PipelineState>

The internal state of a pipeline. The pipeline starts in the DefaultTaskController.TaskState.READY state. The controller then moves the pipeline through states according to the various events that occur, where events are modeled as methods in this class.

Nested Class Summary

Nested classes/interfaces inherited from class java.lang.Enum

Enum.EnumDesc<E extends Enum<E>>

Enum Constant Summary

Enum Constants

Enum Constant	Description
CANCELED	The pipeline is done processing and has shut down.
CANCELING	The user has requested cancellation and the pipeline is in the process of shutting down.
COMPLETED	The pipeline is done processing and has shut down.
FAILED	The pipeline is done processing and has shut down.
FAILING	One or more tasks have failed and the pipeline is in the process of shutting down.
READY	The initial state of the pipeline.
RUNNING	The pipeline is running.

Method Summary

Modifier and Type	Method	Description
abstract DefaultPipelineController.PipelineState	to(DefaultPipelineController.PipelineState target)	Validate the transition from this state to the target state.
static DefaultPipelineController.PipelineState	valueOf(String name)	Returns the enum constant of this class with the specified name.
static DefaultPipelineController.PipelineState[]	values()	Returns an array containing the constants of this enum class, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, describeConstable, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Details

READY

public static final DefaultPipelineController.PipelineState READY

The initial state of the pipeline. On task start, the controller immediately moves to RUNNING.

RUNNING

public static final DefaultPipelineController.PipelineState RUNNING

The pipeline is running. The following conditions must be true:

• One or more tasks have been started
• No tasks have failed
• The user has not requested cancellation

The controller stays in this state until one of the following events:

• If all tasks are started and subsequently complete, then move to COMPLETED
• If the user requests cancellation, then move to CANCELING.
• If a task fails, then move to FAILING. If it is the last task, then move to FAILED instead.

CANCELING

public static final DefaultPipelineController.PipelineState CANCELING

The user has requested cancellation and the pipeline is in the process of shutting down. The following conditions must be true:

• The user has requested cancellation
• At least one task is still running
• No tasks have failed

The controller stays in this state until one of the following events:

• If the last worker completes or cancels, then move to CANCELED.
• If a task fails, then move to FAILING. If it is the last task, then move to FAILED instead.

FAILING

public static final DefaultPipelineController.PipelineState FAILING

One or more tasks have failed and the pipeline is in the process of shutting down. The following conditions must be true:

• At least one task has failed
• At least one task is still running

The controller stays in this state until one of the following events:

• The last task completes, fails, or cancels, then move to FAILED.

COMPLETED

public static final DefaultPipelineController.PipelineState COMPLETED

The pipeline is done processing and has shut down. The user did not request cancellation, and all tasks completed normally. This is a terminal state.

CANCELED

public static final DefaultPipelineController.PipelineState CANCELED

The pipeline is done processing and has shut down. The user requested cancellation, and all tasks either completed normally or canceled. This is a terminal state.

FAILED

public static final DefaultPipelineController.PipelineState FAILED

The pipeline is done processing and has shut down. At least one task failed. This is a terminal state.

Method Details

values

public static DefaultPipelineController.PipelineState[] values()

Returns an array containing the constants of this enum class, in the order they are declared.

Returns:

an array containing the constants of this enum class, in the order they are declared

valueOf

public static DefaultPipelineController.PipelineState valueOf(String name)

Returns the enum constant of this class with the specified name. The string must match exactly an identifier used to declare an enum constant in this class. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum class has no constant with the specified name

NullPointerException - if the argument is null

to

public abstract DefaultPipelineController.PipelineState to(DefaultPipelineController.PipelineState target)

Validate the transition from this state to the target state. The controller will call this method to validate the transition before moving to the target state. If the transition is valid, the method will return the target state. If the transition is invalid, the method will throw an IllegalStateException.

Parameters:

target - the target state

Returns:

the target state, if the transition is valid

Throws:

IllegalStateException - if the transition is invalid