dotnet-cqrs/Svrnty.CQRS.Events.Abstractions/Delivery/IEventDeliveryProvider.cs

88 lines
3.2 KiB
C#

using System;
using Svrnty.CQRS.Events.Abstractions.Delivery;
using Svrnty.CQRS.Events.Abstractions.EventStore;
using System.Threading;
using System.Threading.Tasks;
namespace Svrnty.CQRS.Events.Abstractions.Delivery;
/// <summary>
/// Abstraction for event delivery mechanisms (gRPC, RabbitMQ, Kafka, etc.).
/// </summary>
/// <remarks>
/// <para>
/// Delivery providers are responsible for transporting events from the stream store
/// to consumers using a specific protocol or technology.
/// </para>
/// <para>
/// <strong>Phase 1 Implementation:</strong>
/// gRPC bidirectional streaming for low-latency push-based delivery.
/// </para>
/// <para>
/// <strong>Future Implementations:</strong>
/// - RabbitMQ provider for cross-service messaging
/// - Kafka provider for high-throughput scenarios
/// - SignalR provider for browser clients
/// </para>
/// </remarks>
public interface IEventDeliveryProvider
{
/// <summary>
/// Name of this delivery provider (e.g., "gRPC", "RabbitMQ", "Kafka").
/// </summary>
string ProviderName { get; }
/// <summary>
/// Notify the provider that a new event has been enqueued and is ready for delivery.
/// </summary>
/// <param name="streamName">The name of the stream containing the event.</param>
/// <param name="event">The event that was enqueued.</param>
/// <param name="cancellationToken">Cancellation token.</param>
/// <returns>A task representing the async notification.</returns>
/// <remarks>
/// <para>
/// This method is called by the event stream store when new events arrive.
/// The provider can then push the event to connected consumers or queue it
/// for later delivery.
/// </para>
/// <para>
/// <strong>Important:</strong>
/// This method should be fast and non-blocking. Heavy work should be offloaded
/// to background tasks or channels.
/// </para>
/// </remarks>
Task NotifyEventAvailableAsync(
string streamName,
ICorrelatedEvent @event,
CancellationToken cancellationToken = default);
/// <summary>
/// Start the delivery provider (initialize connections, background workers, etc.).
/// </summary>
/// <param name="cancellationToken">Cancellation token.</param>
/// <returns>A task that completes when the provider is started.</returns>
Task StartAsync(CancellationToken cancellationToken = default);
/// <summary>
/// Stop the delivery provider (close connections, shutdown workers, etc.).
/// </summary>
/// <param name="cancellationToken">Cancellation token.</param>
/// <returns>A task that completes when the provider is stopped.</returns>
Task StopAsync(CancellationToken cancellationToken = default);
/// <summary>
/// Get the number of active connections/consumers for this provider.
/// </summary>
/// <returns>The number of active consumers.</returns>
/// <remarks>
/// Used for monitoring and metrics.
/// </remarks>
int GetActiveConsumerCount();
/// <summary>
/// Check if this provider is currently healthy and ready to deliver events.
/// </summary>
/// <returns>True if healthy, false otherwise.</returns>
bool IsHealthy();
}