Overriding Existing Methods

REN’s in-memory cache service is built to be extended and customized. All major methods are marked as virtual—allowing you to override any operation and tailor caching behavior for your project’s unique needs.

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How to Override?

1. Create a New Service to Override Existing Method

public class OverridedRENInMemoryCacheService(IMemoryCache memoryCache) 
    : RENInMemoryCacheService(memoryCache)
{
    public override async Task<T> GetAsync<T>(string cacheKey, 
        CancellationToken cancellationToken = default)
    {
        Console.WriteLine($"OverridedRENInMemoryCacheService GetAsync called");
        // You can add custom logic here before calling the base method
        return await base.GetAsync<T>(cacheKey, cancellationToken);
    }
}

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2. Register Your Custom Implementation

builder.Services.AddRENCaching<OverridedRENInMemoryCacheService>(CacheType.InMemory);

In the above example, OverridedRENInMemoryCacheService is your custom implementation that inherits from RENInMemoryCacheService. By passing it as the generic type parameter TCacheService, you instruct the DI container to use your custom cache logic for all cache operations.

Here’s how the registration method works under the hood:

public static void AddRENCaching<TCacheService>(this IServiceCollection services, CacheType cacheType, Func<IServiceProvider, IConnectionMultiplexer>? implementationFactory = null, RedisMultiplexerLifetime? multiplexerLifetime = null)
    where TCacheService : IRENCacheService
{
    switch (cacheType)
    {
        case CacheType.InMemory:
            AddInMemoryRENCache<TCacheService>(services);
            break;
        case CacheType.Redis:
            AddRedisRENCache<RENRedisCacheService>(services, implementationFactory, multiplexerLifetime.Value);
            break;
        default:
            throw new ArgumentOutOfRangeException(nameof(cacheType), cacheType, null);
    }
}

 private static void AddInMemoryRENCache<TCacheService>(this IServiceCollection services)
     where TCacheService : IRENCacheService
 {
     services.AddMemoryCache();
     services.RegisterRENCacheServices<TCacheService>();
 }
 
 private static IServiceCollection RegisterRENCacheServices<TCacheService>(this IServiceCollection services)
    where TCacheService : IRENCacheService
{
    services.AddScoped(typeof(IRENCacheService), typeof(TCacheService));

    return services;
}

• If you select CacheType.InMemory, your service will be registered as an in-memory cache.

• If you select CacheType.Redis, your service will be registered as a Redis-based cache.

• If you pass an unsupported cache type, an exception is thrown.

Tip:

This pattern allows you to switch between cache providers or override cache behaviors without changing any other part of your codebase—just swap the type in the registration line!

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3. Use Custom Service In Action

[Route("api/[controller]")]
[ApiController]
public class OverridedCacheController(IRENCacheService cacheService) : ControllerBase
{
    [HttpGet("get")]
    public async Task<IActionResult> GetCacheValueAsync(string key)
    {
        var value = await cacheService.GetAsync<string>(key);
        return Ok(value);
    }
}