@callback deliver(context :: Skitter.Strategy.context(), token :: Skitter.Token.t()) ::
  any()

Accept data sent to the operation node and send it to a worker.

This hook is called by the runtime system when data needs to be sent to a given operation (i.e. when a predecessor of the operation node emits data). It receives the data to be sent wrapped in a Skitter.Token.t/0, which contains the name of the port to which the data should be sent.

The result of this hook is ignored. Instead, this hook should use Skitter.Worker.send/2 to transfer the received data to a worker.

Context

All context data (operation, strategy and deployment data) is available when this hook is called.

@callback deploy(context :: Skitter.Strategy.context(), Skitter.Workflow.args()) ::
  Skitter.Strategy.deployment()

Deploy an operation over the cluster.

This hook is called by the runtime system when an operation has to be distributed over the cluster. It receives the arguments passed to the operation's node in the workflow definition. Any data returned by this hook is made available to other hooks through the deployment field in Skitter.Strategy.context/0.

Context

When this hook is called, only the current strategy and operation are available in the context.

@callback process(
  context :: Skitter.Strategy.context(),
  message :: any(),
  state :: Skitter.Worker.state(),
  role :: Skitter.Worker.role()
) :: Skitter.Worker.state()

Handle a message received by a worker.

This hook is called by the runtime when a worker process receives a message. It is called with the received message, the data of the worker that received the message and its role. This hook should return the new state of the worker that received the message.

Context

All context data (operation, strategy and the deployment data) is available when this hook is called.