ResQ.BuildingBlocks.Adapters.Persistence 0.2.0

ResQ.BuildingBlocks.Adapters.Persistence

The EF Core 9 persistence adapter (driven ring). Provider-agnostic — it references only EF Core and its Relational package, so the consumer picks the provider (Npgsql, SQLite, …) in the configure callback. Depends only on ResQ.BuildingBlocks.Application + ResQ.BuildingBlocks.Domain — never on the messaging adapter (the outbox/inbox use the messaging ports that live in the application core).

The keystone: EfUnitOfWork

EfUnitOfWork is the scoped IUnitOfWork. Its SaveChangesAsync dispatches domain events before the underlying DbContext.SaveChanges, in a drain loop over ChangeTracker.Entries<IHasDomainEvents>():

1. Collect tracked aggregates with pending events, snapshot and clear them.
2. await IDomainEventDispatcher.DispatchAsync(events) — a handler may enqueue an outbox row or raise more events.
3. Repeat until no aggregate has pending events, then call the underlying SaveChangesAsync.

Because dispatch happens inside the same save, outbox rows a handler enqueues commit atomically with the aggregate write. There is deliberately no domain-event-dispatch interceptor: EF's internal service provider does not contain application services. Contract: commits must flow through IUnitOfWork.SaveChangesAsync for domain events to dispatch.

What's in the box

• Repository<TAggregate,TId> / ReadRepository<TAggregate,TId> — specification-driven aggregate repositories; the read side forces AsNoTracking.
• SpecificationEvaluator — bridges the EF-free ISpecification<T> (criteria, includes, ordering, paging, tracking, split-query, ignore-filters) onto an IQueryable<T>.
• TransactionBehavior<TRequest,TResponse> — wraps commands (detected through the CQRS marker interfaces, so ICommand<T> is caught too) in a transaction via EF's execution strategy. Queries pass through.
• AuditInterceptor + IAuditable — a singleton save-changes interceptor that stamps created/modified timestamps from IClock.
• Transactional outbox — OutboxMessage (bytes payload), OutboxMessageConfiguration, IOutbox / EfOutbox (enqueue in the same transaction), OutboxRelay (at-least-once background publisher), OutboxOptions.
• Inbox idempotency — InboxMessage, InboxMessageConfiguration, EfIdempotencyStore (dedupe by (messageId, handler)).
• ModelBuilderExtensions — ApplyResqInfrastructure() maps the outbox/inbox tables; ApplyConfigurationsFrom(assembly) applies your own configs.

Wiring

services.AddResqPersistence<AppDbContext>(
    (sp, options) => options.UseNpgsql(connectionString),
    setup =>
    {
        setup.UseOutbox = true;             // register EfOutbox + OutboxRelay
        setup.UseTransactionBehavior = true; // register TransactionBehavior last (innermost)
        setup.EnableAudit = true;            // attach AuditInterceptor
    });

services.AddResqRepositories(typeof(AppDbContext).Assembly);

AddResqPersistence pools the context (AddDbContextPool), relays a scoped DbContext, and registers EfUnitOfWork/EfIdempotencyStore scoped and AuditInterceptor singleton. In OnModelCreating, call modelBuilder.ApplyResqInfrastructure().ApplyConfigurationsFrom(GetType().Assembly).

Apache-2.0 · part of resq-software/dotnet.