GenDurable (gen_durable v0.1.0)

Durable FSM engine on top of Postgres + GenServer.

Start the engine in a host supervision tree:

{GenDurable,
  repo: MyApp.Repo,
  fsms: [Checkout],
  queues: [default: 10, checkout: 5]}

Then enqueue instances and deliver signals:

{:ok, id} = GenDurable.insert(Checkout, state: %{order: 42}, partition_key: "order:42")
:ok = GenDurable.signal(id, "payment_confirmed", %{amount: 100}, dedup_key: "evt-7")

See gen_durable_spec.md (normative) and gen_durable_plan.md (roadmap).

Summary

Functions

child_spec(opts)

insert(fsm_module, opts \\ [])

Enqueue one FSM instance. Options: :state, :step (default the FSM's :initial), :queue, :priority, :partition_key, :unique_key, :unique_scope, :eligible_at. Returns {:ok, id} or {:error, :duplicate}.

insert_all(fsm_module, entries, opts \\ [])

Batch-enqueue instances in a single statement (dedup via the partial unique index). entries is a list of per-instance option keyword lists. Returns the list of inserted ids (duplicates dropped).

signal(target_id, name, payload \\ %{}, opts \\ [])

Deliver a durable signal to an instance (spec §5). Wakes the instance only on a name match. :dedup_key (default nil) makes redelivery idempotent.

start_link(opts)

See GenDurable.Supervisor.start_link/1.