⚡ BitFaster.Caching

High performance, thread-safe in-memory caching primitives for .NET.

ConcurrentLru

ConcurrentLru is a light weight drop in replacement for ConcurrentDictionary, but with bounded size enforced by the TU-Q eviction policy (similar to 2Q). There are no background threads, no global locks, concurrent throughput is high, lookups are fast and hit rate outperforms a pure LRU in all tested scenarios.

Choose a capacity and use just like ConcurrentDictionary, but with bounded size:

int capacity = 666;
var lru = new ConcurrentLru<string, SomeItem>(capacity);

var value = lru.GetOrAdd("key", (key) => new SomeItem(key));

ConcurrentLfu

ConcurrentLfu is a drop in replacement for ConcurrentDictionary, but with bounded size enforced by the W-TinyLFU eviction policy. ConcurrentLfu has near optimal hit rate. Reads and writes are buffered then replayed asynchronously to mitigate lock contention.

Choose a capacity and use just like ConcurrentDictionary, but with bounded size:

int capacity = 666;
var lfu = new ConcurrentLfu<string, SomeItem>(capacity);

var value = lfu.GetOrAdd("key", (key) => new SomeItem(key));

Documentation

Please refer to the wiki for full API documentation, and a complete analysis of hit rate, latency and throughput.