Demands that the result of the future be available within
timeout.
Demands that the result of the future be available within
timeout. The result is a Return[_] or Throw[_] depending upon
whether the computation finished in time.
Polls for an available result.
Polls for an available result. If the Future has been satisfied, returns Some(result), otherwise None.
Raise the given throwable as an interrupt.
Raise the given throwable as an interrupt. Interrupts are
one-shot and latest-interrupt wins. That is, the last interrupt
to have been raised is delivered exactly once to the Promise
responsible for making progress on the future (multiple such
promises may be involed in flatMap chains).
Raising an interrupt does not alter the externally observable state of the Future. They are used to signal to the producer of the future's value that the result is no longer desired (for whatever reason given in the passed Throwable).
When the computation completes, invoke the given callback function.
When the computation completes, invoke the given callback function. Respond() yields a Try (either a Return or a Throw). This method is most useful for very generic code (like libraries). Otherwise, it is a best practice to use one of the alternatives (onSuccess(), onFailure(), etc.). Note that almost all methods on Future[_] are written in terms of respond(), so this is the essential template method for use in concrete subclasses.
a chained Future[A]
Register a FutureEventListener to be invoked when the computation completes.
Register a FutureEventListener to be invoked when the computation completes. This method is typically used by Java programs because it avoids the use of small Function objects.
Compare this method to transformedBy. The difference is that
addEventListener is used to perform a simple action when a
computation completes, such as recording data in a log-file. It
analogous to a void method in Java: it has side-effects and no
return value. transformedBy, on the other hand, is used to
transform values from one type to another, or to chain a series
of asynchronous calls and return the result. It is analogous to
methods in Java that have a return-type. Note that
transformedBy and addEventListener are not mutually
exclusive and may be profitably combined.
Block, but only as long as the given Timeout.
Block indefinitely, wait for the result of the Future to be available.
Invoked regardless of whether the computation completed successfully or unsuccessfully.
Invoked regardless of whether the computation completed successfully or unsuccessfully.
Implemented in terms of respond so that subclasses control evaluation order. Returns a
chained Future.
If this, the original future, succeeds, run f on the result.
If this, the original future, succeeds, run f on the result.
The returned result is a Future that is satisfied when the original future and the callback, f, are done. If the original future fails, this one will also fail, without executing f.
map()
Converts a Future[Future[B]] into a Future[B]
Invoke the callback only if the Future returns successfully.
Invoke the callback only if the Future returns successfully. Useful for Scala for
comprehensions. Use onSuccess instead of this method for more readable code.
Alias for apply().
Is the result of the Future available yet?
Combines two Futures into one Future of the Tuple of the two results.
If this, the original future, succeeds, run f on the result.
If this, the original future, succeeds, run f on the result.
The returned result is a Future that is satisfied when the original future and the callback, f, are done. If the original future fails, this one will also fail, without executing f.
flatMap()
Invoke the function on the error, if the computation was unsuccessful.
Invoke the function on the error, if the computation was
unsuccessful. Returns a chained Future as in respond.
chained Future
Invoke the function on the result, if the computation was successful.
Invoke the function on the result, if the computation was
successful. Returns a chained Future as in respond.
chained Future
A synonym for select(): Choose the first Future to succeed.
Send updates from this Future to the other.
Send updates from this Future to the other.
other must not yet be satisfied.
Choose the first Future to succeed.
Choose the first Future to succeed.
another Future
a new Future whose result is that of the first of this and other to return
Convert a Twitter Future to a Java native Future.
Convert a Twitter Future to a Java native Future. This should match the semantics of a Java Future as closely as possible to avoid issues with the way another API might use them. See:
http://download.oracle.com/javase/6/docs/api/java/util/concurrent/Future.html#cancel(boolean)
An offer for this future.
An offer for this future. The offer is activated when the future is satisfied.
Transform the Future[A] into a Future[B] using the FutureTransformer.
Transform the Future[A] into a Future[B] using the FutureTransformer. The FutureTransformer handles both success (Return) and failure (Throw) values by implementing map/flatMap and handle/rescue. This method is typically used by Java programs because it avoids the use of small Function objects.
Compare this method to addEventListener. The difference is
that addEventListener is used to perform a simple action when
a computation completes, such as recording data in a log-file.
It analogous to a void method in Java: it has side-effects and
no return value. transformedBy, on the other hand, is used to
transform values from one type to another, or to chain a series
of asynchronous calls and return the result. It is analogous to
methods in Java that have a return-type. Note that
transformedBy and addEventListener are not mutually
exclusive and may be profitably combined.
Note: The FutureTransformer must implement either flatMap
or map and may optionally implement handle. Failing to
implement a method will result in a run-time (AbstractMethod)
error.
Convert this Future[A] to a Future[Unit] by discarding the result.
Convert this Future[A] to a Future[Void] by discarding the result.
Returns a Future[Boolean] indicating whether two Futures are equivalent.
Returns a Future[Boolean] indicating whether two Futures are equivalent. Note that Future.exception(e).willEqual(Future.exception(e)) == Future.value(true).
Returns a new Future that will error if this Future does not return in time.
Returns a new Future that will error if this Future does not return in time.
indicates how long you are willing to wait for the result to be available.
Same as the other within, but with an implicit timer.
Same as the other within, but with an implicit timer. Sometimes this is more convenient.
(Since version 6.0.0) Provided for API compatibility; use raise() instead.
(Since version 5.x) 'void' is a reserved word in javac.
A computation evaluated asynchronously. This implementation of Future does not assume any concrete implementation; in particular, it does not couple the user to a specific executor or event loop.
Note that this class extends Try[_] indicating that the results of the computation may succeed or fail.
Futures are also com.twitter.util.Cancellable, but with special semantics: the cancellation signal is only guaranteed to be delivered when the promise has not yet completed.