Modules
Routes external events to durable statifier executions, creating them when absent.
The address table's own two functions: reap/2, which removes address
rows whose execution finished longer ago than their horizon (ADR-0002,
sections 5 and 6), and by_execution/2, which reads the row naming one
execution.
A binding: the declaration that routes an event from a source to one execution of one document, as ADR-0001 fixes it.
The Broadway front: a pipeline that hands every message its producer
emits to StatifierRouter.route/3.
The router's resolved configuration: the host's repo, where this package's tables live in it, the bindings events are routed by, the module each delivery is handed to, and what that module needs to reach statifier_persistence.
Dedupe on (binding_id, message_id), with a row expiry (ADR-0003,
section 6).
The delivery module StatifierRouter.Config names by default: one
binding's delivery of one event, as one transaction on the host's repo
(ADR-0003, section 1).
Versioned migrations for this package's tables, in the shape
statifier_persistence's StatifierPersistence.Ecto.Migrations uses: the
host writes one ordinary migration that delegates here, and later
package versions ship higher-numbered migration modules the same call
picks up.
V01 of the package DDL: the three tables the decision records fix, each
named by StatifierRouter.Config.table/2 under the host's table prefix
and created in the host's Postgres schema when one is set.
V02 of the package DDL: the subscription table ADR-0007, section 6 fixes,
named by StatifierRouter.Config.table/2 under the host's table prefix
and created in the host's Postgres schema when one is set.
The address table's vote on a chart retirement:
StatifierPersistence.PinSource implemented over the address rows.
The host's answer to which chart a new execution of a document starts on (ADR-0002, section 4).
A resolver over a fixed map of compiled charts, for tests and for a host whose charts are compiled at boot.
The behaviour a host implements for one named outbound destination
(ADR-0005, decision 2). A chart names a route in a <send>'s target
under a type the host registered, and
StatifierRouter.SendHandler hands the built event to the module
registered for that name.
The publish-time checks a host runs over a chart before it lets that chart reach a route (ADR-0005, decision 7).
The Ecto schemas over this package's four tables, one per table
StatifierRouter.Migrations.V01 and StatifierRouter.Migrations.V02
create
A row of the address table: (scope, document, key) -> execution_id
(ADR-0002, section 1). terminal_seen_at is empty until this package
first sees the execution terminal (ADR-0002, section 5).
A row of the dedupe table: one (binding_id, message_id) pair and the
time it stops counting, expires_at (ADR-0003, section 6). A row whose
expires_at has passed counts as absent even before it is removed.
A row of the routing ledger: one recorded outcome of one routing attempt for one binding (ADR-0004, section 4). The ledger is append-only.
A row of the subscription table: one live source invocation, as
(execution_id, binding_id, invoke_id), carrying the scope and key
the subscription reads events under (ADR-0007, section 6). Both are
resolved once, at subscribe time, from the execution's own address row.
The one module that serves both shapes a registered type's <send>
reaches a host in (ADR-0005, decision 5). It implements
Statifier.Send.Processor for a live Statifier.Session, and it offers
handle_effect/3 for a process-less host to call from
StatifierPersistence.Executor.execute/2. Both entry points compose the
same key, resolve the same route name, and reach the same adapter, so
there is no second implementation to keep in step.
The source invoke's two calls, as a host's invoke handler makes them:
start/3 turns a %Statifier.Effect.Invoke{} into
StatifierRouter.subscribe/3, and cancel/3 turns the
%Statifier.Effect.CancelInvoke{} the engine emits on state exit into
StatifierRouter.cancel/2 (ADR-0007, section 2). An invocation's
lifetime is a subscription's, and the chart writes no cleanup for it.
The behaviour a host implements for the durable timer queue a delayed route send is recorded on (ADR-0005, decision 5).
The webhook front: a Plug-shaped helper that turns one already-verified
webhook request into a routing attempt. This package verifies nothing.
The host authenticates the request - typically a provider's signature over
the raw body - and calls handle/3 only after that verification has
passed. A request that reaches this module is one the host has already
vouched for.