KillableGraphStageLogic

Abort outstanding (suspended) emissions for the given outlet, if there are any. This will reinstall the replaced handler that was in effect before the emit call.

Abort outstanding (suspended) reading for the given inlet, if there is any. This will reinstall the replaced handler that was in effect before the read call.

INTERNAL API

INTERNAL API

Requests to stop receiving events from a given input port. Cancelling clears any ungrabbed elements from the port.

Requests to stop receiving events from a given input port. Cancelling clears any ungrabbed elements from the port.

If cancellation is due to an error, use cancel(in, cause) instead to propagate that cause upstream. This overload is a shortcut for cancel(in, SubscriptionWithCancelException.NoMoreElementsNeeded)

Automatically invokes or complete on all the input or output ports that have been called, then marks the stage as stopped.

Signals that there will be no more elements emitted on the given port.

Automatically invokes or complete on all the input or output ports that have been called, then marks the operator as stopped.

Input handler that terminates the state upon receiving completion if the given condition holds at that time. The operator fails upon receiving a failure.

Output handler that terminates the state upon receiving completion if the given condition holds at that time. The operator fails upon receiving a failure.

Java API: Obtain a callback object that can be used asynchronously to re-enter the current GraphStage with an asynchronous notification. The invoke method of the returned AsyncCallback is safe to be called from other threads. It will in the background thread-safely delegate to the passed callback function. I.e. invoke will be called by other thread and the passed handler will be invoked eventually in a thread-safe way by the execution environment.

AsyncCallback.invokeWithFeedback has an internal promise that will be failed if event cannot be processed due to stream completion.

This object can be cached and reused within the same GraphStageLogic.

Input handler that terminates the operator upon receiving completion. The operator fails upon receiving a failure.

Output handler that terminates the operator upon cancellation.

Emit an element through the given outlet, suspending execution if necessary. This action replaces the OutHandler for the given outlet if suspension is needed and reinstalls the current handler upon receiving an onPull() signal.

Emit an element through the given outlet and continue with the given thunk afterwards, suspending execution if necessary. This action replaces the OutHandler for the given outlet if suspension is needed and reinstalls the current handler upon receiving an onPull() signal (before invoking the andThen function).

Emit a sequence of elements through the given outlet, suspending execution if necessary. This action replaces the OutHandler for the given outlet if suspension is needed and reinstalls the current handler upon receiving an onPull() signal.

Emit a sequence of elements through the given outlet and continue with the given thunk afterwards, suspending execution if necessary. This action replaces the OutHandler for the given outlet if suspension is needed and reinstalls the current handler upon receiving an onPull() signal (before invoking the andThen function).

Java API

Emit a sequence of elements through the given outlet, suspending execution if necessary. This action replaces the AbstractOutHandler for the given outlet if suspension is needed and reinstalls the current handler upon receiving an onPull() signal.

Java API

Emit a sequence of elements through the given outlet, suspending execution if necessary. This action replaces the AbstractOutHandler for the given outlet if suspension is needed and reinstalls the current handler upon receiving an onPull() signal.

Emit a sequence of elements through the given outlet, suspending execution if necessary. This action replaces the OutHandler for the given outlet if suspension is needed and reinstalls the current handler upon receiving an onPull() signal.

Emit a sequence of elements through the given outlet and continue with the given thunk afterwards, suspending execution if necessary. This action replaces the OutHandler for the given outlet if suspension is needed and reinstalls the current handler upon receiving an onPull() signal (before invoking the andThen function).

Signals failure through the given port.

Automatically invokes or fail on all the input or output ports that have been called, then marks the operator as stopped.

Obtain a callback object that can be used asynchronously to re-enter the current GraphStage with an asynchronous notification. The invoke method of the returned AsyncCallback is safe to be called from other threads. It will in the background thread-safely delegate to the passed callback function. I.e. invoke will be called by other thread and the passed handler will be invoked eventually in a thread-safe way by the execution environment.

In case stream is not yet materialized AsyncCallback will buffer events until stream is available.

AsyncCallback.invokeWithFeedback has an internal promise that will be failed if event cannot be processed due to stream completion.

To be thread safe this method must only be called from either the constructor of the graph operator during materialization or one of the methods invoked by the graph operator machinery, such as onPush and onPull.

This object can be cached and reused within the same GraphStageLogic.

INTERNAL API

To be thread safe this method must only be called from either the constructor of the graph operator during materialization or one of the methods invoked by the graph operator machinery, such as onPush and onPull.

Retrieves the current callback for the events on the given Outlet

Retrieves the current callback for the events on the given Inlet

Initialize a StageActorRef which can be used to interact with from the outside world "as-if" an Actor. The messages are looped through the getAsyncCallback mechanism of GraphStage so they are safe to modify internal state of this operator.

This method must (the earliest) be called after the GraphStageLogic constructor has finished running, for example from the preStart callback the graph operator logic provides.

Created StageActorRef to get messages and watch other actors in synchronous way.

The StageActorRef's lifecycle is bound to the operator, in other words when the operator is finished, the Actor will be terminated as well. The entity backing the StageActorRef is not a real Actor, but the GraphStageLogic itself, therefore it does not react to PoisonPill.

To be thread safe this method must only be called from either the constructor of the graph operator during materialization or one of the methods invoked by the graph operator machinery, such as onPush and onPull.

Once the callback InHandler.onPush for an input port has been invoked, the element that has been pushed can be retrieved via this method. After has been called the port is considered to be empty, and further calls to grab will fail until the port is pulled again and a new element is pushed as a response.

The method isAvailable can be used to query if the port has an element that can be grabbed or not.

Indicates whether there is already a pending pull for the given input port. If this method returns true then isAvailable must return false for that same port.

Input handler that does not terminate the operator upon receiving completion. The operator fails upon receiving a failure.

Output handler that does not terminate the operator upon cancellation.

Return true if the given output port is ready to be pushed.

Indicates whether there is an element waiting at the given input port. can be used to retrieve the element. After calling grab this method will return false.

If this method returns true then hasBeenPulled will return false for that same port.

Indicates whether the port has been closed. A closed port cannot be pushed.

Indicates whether the port has been closed. A closed port cannot be pulled.

The akka.stream.Materializer that has set this GraphStage in motion.

Can not be used from a GraphStage constructor. Access to materializer is provided by the , and akka.stream.scaladsl.Sink.fromMaterializer and their corresponding Java API factories.

Install a handler on the given inlet that emits received elements on the given outlet before pulling for more data. doFinish and doFail control whether completion or failure of the given inlet shall lead to operator termination or not. doPull instructs to perform one initial pull on the from port.

Invoked after processing of external events stopped because the operator is about to stop or fail.

Invoked before any external events are processed, at the startup of the operator.

Requests an element on the given port. Calling this method twice before an element arrived will fail. There can only be one outstanding request at any given time. The method hasBeenPulled can be used query whether pull is allowed to be called or not. This method will also fail if the port is already closed.

Emits an element through the given output port. Calling this method twice before a has been arrived will fail. There can be only one outstanding push request at any given time. The method isAvailable can be used to check if the port is ready to be pushed or not.

Java API: Read an element from the given inlet and continue with the given function, suspending execution if necessary. This action replaces the InHandler for the given inlet if suspension is needed and reinstalls the current handler upon receiving the onPush() signal (before invoking the andThen function).

Read an element from the given inlet and continue with the given function, suspending execution if necessary. This action replaces the InHandler for the given inlet if suspension is needed and reinstalls the current handler upon receiving the onPush() signal (before invoking the andThen function).

Java API: Read a number of elements from the given inlet and continue with the given function, suspending execution if necessary. This action replaces the InHandler for the given inlet if suspension is needed and reinstalls the current handler upon receiving the last onPush() signal (before invoking the andThen function).

Read a number of elements from the given inlet and continue with the given function, suspending execution if necessary. This action replaces the InHandler for the given inlet if suspension is needed and reinstalls the current handler upon receiving the last onPush() signal.

If upstream closes before N elements have been read, the onClose function is invoked with the elements which were read.

Assigns callbacks for the events for an Outlet

Assigns callbacks for the events for an Inlet

Assign callbacks for linear operator for both and Outlet

Controls whether this operator shall shut down when all its ports are closed, which is the default. In order to have it keep going past that point this method needs to be called with a true argument before all ports are closed, and afterwards it will not be closed until this method is called with a false argument or the operator is terminated via completeStage() or failStage().

Override and return a name to be given to the StageActor of this operator.

This method will be only invoked and used once, during the first getStageActor invocation whichc reates the actor, since subsequent getStageActors calls function like become, rather than creating new actors.

Returns an empty string by default, which means that the name will a unique generated String (e.g. "$$a").

An akka.stream.Materializer that may run fusable parts of the graphs that it materializes within the same actor as the current GraphStage (if fusing is available). This materializer must not be shared outside of the GraphStage.

Input handler that does not terminate the operator upon receiving completion nor failure.

Requests an element on the given port unless the port is already closed. Calling this method twice before an element arrived will fail. There can only be one outstanding request at any given time. The method hasBeenPulled can be used query whether pull is allowed to be called or not.