Rask.Cache 0.23.1-alpha.0.70

Rask.Cache

A developer-facing cache for a Rask app — stored in the app's own database, with no broker or Redis.

• Implements the standard IDistributedCache, so it drops straight into ASP.NET session state, output caching, and anything else built on the abstraction.
• A typed surface that reads as a sentence, with nothing injected: Cache.Remember(key, load).For(10.Minutes) read-through, plus Cache.Get<T> / Cache.Set(key, value).For(…) / Cache.Forget (JSON under the hood). ICache words the same calls for a hosted service or a timer.
• Entries carry absolute and sliding expirations; a read renews a sliding entry and an expired entry is evicted lazily. A background CachePurger sweeps expired rows on an interval.

Use

// Program.cs
builder.Services.AddRaskCache<AppDbContext>();

// AppDbContext.OnModelCreating:  modelBuilder.AddRaskCache();
// then:  rask db add AddCache && rask db update

// read-through: the factory runs once on a miss, then the value is served from the DB.
var rates = await Cache.Remember($"rates:{date:yyyyMMdd}", ct => exchange.FetchRatesAsync(date, ct))
    .Sliding(10.Minutes);

Register your context as an IDbContextFactory<AppDbContext> (Rask Server sessions are long-lived) and run one purger per app — SQLite is single-writer.

Already running Redis?

ICache works over any IDistributedCache, so point it at the one you have — no CacheEntry table, no purge worker, no migration:

builder.Services.AddStackExchangeRedisCache(o => o.Configuration = "localhost:6379");
builder.Services.AddRaskCache();   // no <AppDbContext>

There is deliberately no Rask.Cache.Redis package — Microsoft.Extensions.Caching.StackExchangeRedis is the standard .NET API for this. The overload takes no CacheOptions, because both of them are implemented by the database-backed store and would silently do nothing against another one.

Isolated per tenant. In a multi-tenant app the database-backed store scopes each key to the tenant in flight, so every tenant gets its own value under the same name and cannot read another's; with no tenant the key is stored as given, which keeps anonymous session and output caching working.

Trim / AOT: the typed Remember<T>/Get<T>/Set<T> surface round-trips values through System.Text.Json, which by default means reflection. In a trimmed or AOT app, name a source-generated JsonSerializerContext once — o.Json = AppJson.Default — and every call stays as it is. The IDistributedCache (byte[]) surface is fully trim-safe.