Hflex.MediatR.Extensions.Caching

Caching extension for MediatR

Inspired by https://github.com/Iamcerba/AspNetCore.CacheOutput

Installation

1. Install-Package Hflex.MediatR.Extensions.Redis for distributed cache via Redis or Install-Package Hflex.MediatR.Extensions.InMemoryCaching for in memory caching.
2. Define configurations for caching

var cachingConfigurations = new CachingConfiguration(); //GetTodoItemsQuery will be invalidated, when timer notification will be fired on InvalidateCacheHostedService cachingConfigurations.AddConfiguration<GetTodoItemsQuery>(duration: TimeSpan.FromMinutes(2), false); //GetWeatherForecastsQuery will be invalidated, when UpdateWeatherForecastsCommand called cachingConfigurations.AddConfiguration<GetWeatherForecastsQuery>(TimeSpan.FromMinutes(10), false, null, typeof(UpdateWeatherForecastsCommand));

3. In Startup.cs or Program.cs Register accordingly

• In case of Redis use builder.Services.AddRedisCache(cachingConfigurations, builder.Configuration.GetConnectionString("RedisConnectionString"));
• In case of InMemory use builder.Services.AddInMemoryCache(cachingConfigurations);

Usage

Everything does configuration, just register

var cachingConfigurations = new CachingConfiguration(); cachingConfigurations.AddConfiguration<GetWeatherForecastsQuery>(duration: TimeSpan.FromMinutes(10),//Cache duration perUser: false, //Set to true for caching per user (includes userID into cache key) keyFactory: null, //Create Func<string> for replacing default key, which is serialized json from request object invalidatesOnRequests: typeof(UpdateWeatherForecastsCommand), typeof(secondcommand), typeof(thirdCommand) ..... //Command types to invalidate query);

like this for GetWeatherForecastsQuery query, which will get cached for 10 minutes. And once any of invalidatesOnRequests called it will get invalidated automatically. Alternative way of force invalidating queries is to use Notifications. Just publish

_mediator.Publish(new InvalidateCacheNotification { RequestTypes = new Type[]{ typeof(queryType1), typeof(queryType2), ...}});

anywhere in the application e.g. in samples I use hostedService with timer to simulate some domain events, which invalidates GetTodoItemsQuery

_mediator.Publish(new InvalidateCacheNotification { RequestTypes = new []{typeof(GetTodoItemsQuery)} });