Class EventSourcingServiceCollectionExtensions

Namespace

Microsoft.Extensions.DependencyInjection

Assembly

Stratara.Infrastructure.dll

Service-collection extensions for the Stratara event-sourcing runtime and the event-stream hashing worker.

public static class EventSourcingServiceCollectionExtensions

Inheritance

object

EventSourcingServiceCollectionExtensions

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Methods

AddEventSourcing(IServiceCollection)

Registers the core event-sourcing services as scoped: IEventSource, IAggregationService, IChangeSetHandler, IEventTypeResolver, and ISnapshotService. Also contributes the default VersionThresholdSnapshotStrategy via TryAddSingleton, and the default event-upcaster pipeline and trusted-type resolver where none is registered.

public static IServiceCollection AddEventSourcing(this IServiceCollection services)

Parameters

services IServiceCollection

The service collection.

Returns

IServiceCollection

The same service collection for chaining.

Examples

Pair it with a write store; on its own it registers the services but nothing to persist through:

services.AddEventSourcing();
services.AddNpgsqlWriteDbContextFactory<AppWriteDbContext>();

Remarks

To control the snapshot cadence — vary it per aggregate type, change the threshold, or disable snapshots with NoSnapshotStrategy — register your own singleton ISnapshotStrategy. A custom registration overrides the default.

This call registers no IStoreConflictDetector: the store registration that knows the provider does — AddNpgsqlWriteDbContextFactory for PostgreSQL, the test-support store for SQLite. A host that registers its write context another way, or brings another provider, registers a detector itself; without one, a duplicate stream version is not recognised as a ConcurrencyException.

The call reads EventSourcingOptions from the EventSourcing section of the configuration the container holds, where it holds one: EventSourcing:AppendAgainstAggregatedVersion (default false) makes every append that follows a rebuild through IAggregationService conditional on the version that rebuild saw; EventSourcing:NewStreamOwnerFromSession (Allow, the default, Warn or Refuse) decides what happens when a new stream's first event would take its owner from the session. A value that names no policy fails the host's start. The section is read at the position of the first call, so a Configure<EventSourcingOptions> that must win over it comes after this call.

AddEventStreamHashWorker(IServiceCollection)

Registers Stratara.Infrastructure.EventSourcing.EventStreamHashWorker as a hosted service and the supporting IEventStreamHashService / IEventChainService implementations.

public static IServiceCollection AddEventStreamHashWorker(this IServiceCollection services)

Parameters

services IServiceCollection

The service collection.

Returns

IServiceCollection

The same service collection for chaining.

Examples

services.AddEventStreamHashWorker();

Remarks

Only one host across the deployment should run the hash worker. The worker computes SHA-256 chain hashes over committed events and writes periodic anchors; running it on multiple hosts can produce duplicate anchors and hash-update conflicts.