FastCache

6x-10x faster alternative to MemoryCache

TL;DR

Bascially it's just a ConcurrentDictionary with expiration.

Why FastCache is better than System.Runtime.Caching.MemoryCache and Microsoft.Extensions.Caching.MemoryCache.

• 6X faster read times than MemeoryCache.
• 10x faster wites than MemoryCache
• Thread safe and atomic writes
• MemoryCache's come with performnce counters that can't be turned off

Usage

var cache = new FastCache<string, int>();
cache.AddOrUpdate("key", 42, TimeSpan.FromMinutes(1));
cache.TeyGet("key", out int value);
cache.GetOrAdd("key", k => 1024, TimeSpan.FromMilliseconds(100));

Tradeoffs

FastCache uses Environment.TickCount which is 26x times faster tham DateTime.Now. But Environment.TickCount is limited to Int32. Which means it reset to int.MinValue once overflowed. In practice this means you cannot cache stuff for more than ~25 days (2.4 billion milliseconds).

Another tradeoff: MemoryCache watches the used memory, and evicts items once it senses memory pressure. FastCache does not do that it is up to you. It's just a dictionary.

Benchmarks

|               Method |      Mean |     Error |   StdDev |   Gen0 | Allocated |
|--------------------- |----------:|----------:|---------:|-------:|----------:|
|      FastCacheLookup |  67.15 ns |  2.582 ns | 0.142 ns |      - |         - |
|    MemoryCacheLookup | 426.60 ns | 60.162 ns | 3.298 ns | 0.0200 |     128 B |
|   FastCacheAddRemove |  99.97 ns | 12.040 ns | 0.660 ns | 0.0254 |     160 B |
| MemoryCacheAddRemove | 710.70 ns | 32.415 ns | 1.777 ns | 0.0515 |     328 B |