38 lines
1.7 KiB
C#
38 lines
1.7 KiB
C#
|
using MediatR;
|
|||
|
|
using ZeroFramework.DeviceCenter.Infrastructure.Idempotency;
|
|||
|
|
|
|||
|
|
namespace ZeroFramework.DeviceCenter.Application.Infrastructure
|
|||
|
|
{
|
|||
|
|
/// <summary>
|
|||
|
|
/// Provides a base implementation for handling duplicate request and ensuring idempotent updates, in the cases where
|
|||
|
|
/// a requestid sent by client is used to detect duplicate requests.
|
|||
|
|
/// </summary>
|
|||
|
|
public class IdentifiedCommandHandler<TRequest, TResponse>(IMediator mediator, IRequestManager requestManager) : IRequestHandler<IdentifiedCommand<TRequest, TResponse>, TResponse> where TRequest : IRequest<TResponse>
|
|||
|
|
{
|
|||
|
|
private readonly IMediator _mediator = mediator;
|
|||
|
|
|
|||
|
|
private readonly IRequestManager _requestManager = requestManager;
|
|||
|
|
|
|||
|
|
/// <summary>
|
|||
|
|
/// Creates the result value to return if a previous request was found
|
|||
|
|
/// </summary>
|
|||
|
|
protected virtual TResponse? CreateResultForDuplicateRequest() => default;
|
|||
|
|
|
|||
|
|
/// <summary>
|
|||
|
|
/// This method handles the command. It just ensures that no other request exists with the same ID, and if this is the case
|
|||
|
|
/// just enqueues the original inner command.
|
|||
|
|
/// </summary>
|
|||
|
|
public async Task<TResponse> Handle(IdentifiedCommand<TRequest, TResponse> command, CancellationToken cancellationToken)
|
|||
|
|
{
|
|||
|
|
if (await _requestManager.ExistAsync(command.Id))
|
|||
|
|
{
|
|||
|
|
return CreateResultForDuplicateRequest() ?? throw new NotImplementedException();
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
await _requestManager.CreateRequestForCommandAsync<TRequest>(command.Id);
|
|||
|
|
|
|||
|
|
// Send the embeded business command to mediator so it runs its related CommandHandler
|
|||
|
|
return await _mediator.Send(command.Command, cancellationToken);
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
}
|