View Source Finitomata.Persistency behaviour (Finitomata v0.20.1)

The behaviour to be implemented by a persistent storage to be used with Finitomata (pass the implementation as persistency: Impl.Module.Name to use Finitomata.)

Once declared, the initial state would attempt to load the current state from the storage using load/1 funtcion which should return the {state, payload} tuple.

Summary

Types

transition_info()

Callbacks

load(id)

The function to be called from init/1 callback upon FSM start to load the state and payload from the persistent storage

store(id, object, transition)

The function to be called from on_transition/4 handler to allow storing the state and payload to the persistent storage

store_error(id, object, reason, transition)

The function to be called from on_transition/4 handler on non successful transition to allow storing the failed attempt to transition to the persistent storage

Types

transition_info()

@type transition_info() :: %{
  from: Finitomata.Transition.state(),
  to: Finitomata.Transition.state(),
  event: Finitomata.Transition.event(),
  event_payload: Finitomata.event_payload(),
  object: Finitomata.State.payload()
}

Callbacks

load(id)

@callback load(id :: Finitomata.fsm_name()) ::
  {:loaded | :created | :unknown, Finitomata.State.payload()}

The function to be called from init/1 callback upon FSM start to load the state and payload from the persistent storage

store(id, object, transition)

@callback store(
  id :: Finitomata.fsm_name(),
  object :: Finitomata.State.payload(),
  transition :: transition_info()
) :: :ok | {:ok, Finitomata.State.payload()} | {:error, any()}

The function to be called from on_transition/4 handler to allow storing the state and payload to the persistent storage

store_error(id, object, reason, transition)

(optional)

@callback store_error(
  id :: Finitomata.fsm_name(),
  object :: Finitomata.State.payload(),
  reason :: any(),
  transition :: transition_info()
) :: :ok | {:error, any()}

The function to be called from on_transition/4 handler on non successful transition to allow storing the failed attempt to transition to the persistent storage