DurableStateBehavior

Fluent builder for durable-state actor behaviors — persists the full current state as a single snapshot on every write.

What it does

DurableStateBehavior is the simpler persistence model: rather than storing a sequence of domain events, it saves the actor's complete current state on each DurableEffect::persist() call. There is no event replay on startup — the DurableStateEngine loads the latest snapshot from the DurableStateStore and delivers it as the initial state before the first user command arrives. This trades event-history auditability for lower storage overhead and much faster recovery. Use DurableStateBehavior for read-model projections, session state, configuration caches, and any entity where an event log would add cost without adding value.

Example

src/UserProfileActor.php
use Monadial\Nexus\Persistence\PersistenceId;
use Monadial\Nexus\Persistence\State\DurableStateBehavior;
use Monadial\Nexus\Persistence\State\DurableEffect;

$behavior = DurableStateBehavior::create(
    PersistenceId::of('UserProfile', $userId),
    new UserProfile(),
    static fn (ActorContext $ctx, object $cmd, UserProfile $state): DurableEffect => match (true) {
        $cmd instanceof UpdateEmail   => DurableEffect::persist($state->withEmail($cmd->email)),
        $cmd instanceof UpdateName    => DurableEffect::persist($state->withName($cmd->name)),
        $cmd instanceof GetProfile    => DurableEffect::none()
            ->thenReply($ctx->sender(), fn (UserProfile $s) => $s),
        $cmd instanceof DeleteProfile => DurableEffect::persist(UserProfile::deleted())
            ->thenStop(),
        default => DurableEffect::none(),
    },
)
    ->withStateStore($stateStore)
    ->toBehavior();

Key methods

DurableStateBehavior::create(PersistenceId, object $emptyState, Closure $commandHandler): self — entry point; the three required arguments define the full durable-state contract.
->withStateStore(DurableStateStore $store): self — required; the backing store for loading and persisting full state snapshots.
->withWriterId(Ulid $writerId): self — override the ULID stamped on persisted envelopes; useful for deterministic tests or data-migration scenarios.
->toBehavior(): Behavior — compile everything into a Behavior ready to pass to Props::fromBehavior(); throws LogicException if withStateStore() was not called.

Full API reference

Full method list and class hierarchy

What it does​

Example​

Key methods​

Full API reference​

See also​

What it does

Example

Key methods

Full API reference

See also