Kanject.Core.CacheDb

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A cache abstraction — ICacheDb — with three interchangeable providers: DynamoDB, S3 Express One Zone, and in-memory. Store strings or typed objects with an absolute expiry, read them back with a single TryGet, and namespace every key for per-stage isolation. Swap providers by swapping the registration call.

Providers

DynamoDB
`AddDynamoCacheDb(...)` — serverless, TTL-backed cache table. The default for Lambda services. /docs/core-cache
S3 Express
`AddS3ExpressCacheDb(...)` — S3 Express One Zone directory buckets for single-AZ, ultra-low-latency reads.
In-memory
`AddInMemoryCacheDb(namespace)` — same `ICacheDb` surface, in-process. For tests and single-instance workloads.

Install

bash 
dotnet add package Kanject.Core.CacheDb.Provider.DynamoDb# or .Provider.InMemory  (tests / single process)# or .Provider.S3Express (S3 Express One Zone, ultra-low latency)

Each provider is its own package; they all implement ICacheDb from Kanject.Core.CacheDb.Abstractions (pulled in transitively).

Register

csharp 
using Kanject.Core.CacheDb.Provider.DynamoDb.Extensions;​builder.Services.AddDynamoCacheDb(options =>{    options.CacheName = "orders-cache";    options.Namespace = appSettings.Stage;   // per-stage key isolation    options.AwsRegion = appSettings.AwsRegion;    options.TTL       = 15;                   // default item lifetime, in minutes});

The S3 Express provider takes the same shape plus AvailabilityZoneId; the in-memory provider takes just a namespace string. Namespace prefixes every key, so dev and prod can share an account without colliding.

Use it

Inject ICacheDb. Build a namespaced key with FormatCacheKey, try-get, and on a miss compute and store with an absolute expiry (a DateTime, not a relative TTL):

csharp 
public class QuoteService(ICacheDb cache, IPricingApi pricing){    public async Task<string> GetQuoteAsync(string sku)    {        var key = cache.FormatCacheKey("quote", sku);​        var (hit, cached) = await cache.TryGetCacheDataAsync(key);        if (hit) return cached!;​        var quote = await pricing.QuoteAsync(sku);​        // Absolute expiry — pass the DateTime the entry should die at.        await cache.CacheDataAsync(key, quote, DateTime.UtcNow.AddMinutes(5));        return quote;    }}

Typed overloads serialize and deserialize any object; removal takes one or many keys:

csharp 
// Typed overloads serialize/deserialize with System.Text.Json.await cache.CacheDataAsync("basket:" + userId, basket, DateTime.UtcNow.AddHours(1));​var (found, basket) = await cache.TryGetCacheDataAsync<Basket>("basket:" + userId);​// Invalidate one or many keys.await cache.RemoveCachedDataAsync("basket:" + userId);

What ships with it

  • One ICacheDb interface, three providers — DynamoDB, S3 Express One Zone, in-memory
  • CacheDataAsync(key, value, DateTime? expiry) — string and typed (<T>) overloads, System.Text.Json serialization
  • TryGetCacheDataAsync(key) → (bool exists, value) — string and typed overloads
  • RemoveCachedDataAsync(params string[] keys) — invalidate one or many keys
  • FormatCacheKey(params string[] keys) + a Namespace prefix for per-stage / per-tenant isolation
  • Lock, counter-lock, and seat-lock helpers with the same surface across providers
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