Class IteratingNestedCallback

java.lang.Object

org.eclipse.jetty.util.IteratingCallback

org.eclipse.jetty.util.IteratingNestedCallback

All Implemented Interfaces:

Callback, Invocable

public abstract class IteratingNestedCallback
extends IteratingCallback

Iterating Nested Callback.

This specialized callback is used when breaking up an asynchronous task into smaller asynchronous tasks. A typical pattern is that a successful callback is used to schedule the next sub task, but if that task completes quickly and uses the calling thread to callback the success notification, this can result in a growing stack depth.

To avoid this issue, this callback uses an AtomicBoolean to note if the success callback has been called during the processing of a sub task, and if so then the processing iterates rather than recurses.

This callback is passed to the asynchronous handling of each sub task and a call the IteratingCallback.succeeded() on this call back represents completion of the subtask. Only once all the subtasks are completed is the Callback.succeeded() method called on the Callback instance passed the the IteratingNestedCallback(Callback) constructor.

Nested Class Summary

Nested classes/interfaces inherited from class org.eclipse.jetty.util.IteratingCallback

IteratingCallback.Action

Nested classes/interfaces inherited from interface org.eclipse.jetty.util.Callback

Callback.Combination, Callback.Completable, Callback.Completing, Callback.Nested

Nested classes/interfaces inherited from interface org.eclipse.jetty.util.thread.Invocable

Invocable.Callable, Invocable.InvocationType, Invocable.ReadyTask, Invocable.Task

Field Summary

Fields inherited from interface org.eclipse.jetty.util.Callback

NOOP, NOT_CALLED

Fields inherited from interface org.eclipse.jetty.util.thread.Invocable

__nonBlocking

Constructor Summary

Constructors

Constructor	Description
IteratingNestedCallback(Callback callback)

Method Summary

Modifier and Type	Method	Description
Invocable.InvocationType	getInvocationType()
protected void	onCompleteSuccess()	Invoked when the overall task has completed successfully, specifically after any IteratingCallback.Action.SCHEDULED operations have Callback.succeeded() and IteratingCallback.process() has returned IteratingCallback.Action.SUCCEEDED.
protected void	onFailure(Throwable x)	Invoked when the overall task has been aborted or failed.
String	toString()

Methods inherited from class org.eclipse.jetty.util.IteratingCallback

abort, close, failed, isAborted, isClosed, isFailed, isSucceeded, iterate, onAborted, onCompleted, onCompleteFailure, onSuccess, process, reset, succeeded

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.eclipse.jetty.util.Callback

completeWith

Constructor Details

IteratingNestedCallback

public IteratingNestedCallback(Callback callback)

Method Details

getInvocationType

public Invocable.InvocationType getInvocationType()

Returns:

The InvocationType of this object

onCompleteSuccess

protected void onCompleteSuccess()

Description copied from class: IteratingCallback

Invoked when the overall task has completed successfully, specifically after any IteratingCallback.Action.SCHEDULED operations have Callback.succeeded() and IteratingCallback.process() has returned IteratingCallback.Action.SUCCEEDED.

Calls to this method are serialized with respect to IteratingCallback.process(), IteratingCallback.onAborted(Throwable) and IteratingCallback.onCompleted(Throwable). If this method is called, then IteratingCallback.onCompleteFailure(Throwable) ()} will never be called.

Overrides:

onCompleteSuccess in class IteratingCallback

See Also:

• IteratingCallback.onCompleteFailure(Throwable)

onFailure

protected void onFailure(Throwable x)

Description copied from class: IteratingCallback

Invoked when the overall task has been aborted or failed.

Calls to this method are serialized with respect to IteratingCallback.onAborted(Throwable), IteratingCallback.process(), IteratingCallback.onCompleteFailure(Throwable) and IteratingCallback.onCompleted(Throwable).

Because onFailure can be called due to an IteratingCallback.abort(Throwable) or IteratingCallback.close() operation, it is possible that any resources passed to a IteratingCallback.Action.SCHEDULED operation may still be in use, and thus should not be recycled by this call. For example any buffers passed to a write operation should not be returned to a buffer pool by implementations of onFailure. Such resources may be discarded here, or safely recycled in a subsequent call to IteratingCallback.onCompleted(Throwable) or IteratingCallback.onCompleteFailure(Throwable), when the IteratingCallback.Action.SCHEDULED operation has completed.

Overrides:

onFailure in class IteratingCallback

Parameters:

x - The cause of the failure or abort

See Also:

• IteratingCallback.onCompleted(Throwable)
• IteratingCallback.onCompleteFailure(Throwable)

toString

public String toString()

Overrides:

toString in class IteratingCallback