go-freelru
A GC-less, fast, generic LRU hashmap library for Go with optional locking, sharding, eviction, and expiration.
What is go-freelru?
FreeLRU is a Go library that implements a high-performance, GC-less LRU (Least Recently Used) hashmap for caching. It solves the problem of garbage collection overhead in long-running applications with large caches by using a contiguous memory layout and Go generics for type safety. The library provides single-threaded and thread-safe variants optimized for different concurrency levels.
Go developers building performance-sensitive applications that require efficient in-memory caching, such as web servers, data processing pipelines, or real-time systems where low latency and minimal GC pauses are critical.
Developers choose FreeLRU for its exceptional speed, zero-allocation design for non-pointer types, and flexibility in concurrency models. It outperforms many popular Go caching libraries in benchmarks while offering a simple API and configurable memory overcommitment to tune performance.
Overview
FreeLRU is a high-performance LRU (Least Recently Used) caching library for Go designed to eliminate garbage collection overhead and provide type safety through generics. It offers multiple implementations tailored for different concurrency needs, from single-threaded to high-concurrency environments.
Key Features
- GC-less Design — Uses a contiguous array to avoid millions of small heap allocations, reducing garbage collection pauses.
- Generic Type Safety — Leverages Go generics for compile-time type checking and zero runtime allocations for non-pointer types.
- Multiple Concurrency Models — Provides
LRU(single-threaded),SyncedLRU(low-concurrency), andShardedLRU(high-concurrency) implementations. - High Performance — Benchmarks show it outperforms other LRU libraries and even Go maps in many scenarios.
- Configurable Memory Overcommitment — Allows allocating more hashtable memory to reduce collisions and improve speed.
- Exact and Approximate LRU —
LRUandSyncedLRUuse exact LRU algorithms;ShardedLRUuses an approximate algorithm for scalability.
Philosophy
FreeLRU prioritizes performance and low GC overhead by merging hashmap and ringbuffer into a contiguous array, ensuring memory locality and minimizing cache misses. It emphasizes simplicity in API design to ease migration from other LRU implementations.
Related Projects
Found a gem we're missing?
Open-Awesome is built by the community, for the community. Submit a project, suggest an awesome list, or help improve the catalog on GitHub.
