RobGraham / ncache

ncache is a simple Golang in-memory caching solution utilizing sync.Map which is best suited for read heavy cache usage

Introduction

ncache is a simple Golang in-memory caching solution utilizing sync.Map which is best suited for read heavy cache usage.

Getting started

cache, err := ncache.New(&ncache.Config{
    Evict: 10 * time.Minutes, // optional
    OnEvict: func(key, value interface{}) { // optional
        // ... do stuff
    },
})

cache.Set("abc", "some data", 30 * time.Seconds) // Add to cache with TTL of 30 seconds

if v, ok := cache.Get("abc"); ok {
    // Cache found
}

Benchmark

The decision to use sync.Map instead of regular map with Mutex was the significantly improved read times.

Running on a single cpu core (i7-9750H) the results are:

sync.Map

Test	No. Ops	Speed	Bytes/op	Allocations
BenchmarkSet	9887005	114.3 ns/op	40 B/op	2 allocs/op
BenchmarkGet	55380897	23.23 ns/op	0 B/op	0 allocs/op

Map with mutex

Test	No. Ops	Speed	Bytes/op	Allocations
BenchmarkSet	15337158	65.39 ns/op	16 B/op	1 allocs/op
BenchmarkGet	31743174	32.49 ns/op	0 B/op	0 allocs/op

However, the results of sync.Map are more pronounced if using a multi cpu system.

Using all cores (6) of an i7-9750H you'll notice that read is almost 5x faster while write suffers a little.

Test	No. Ops	Speed	Bytes/op	Allocations
BenchmarkSet	6128324	187.5 ns/op	40 B/op	2 allocs/op
BenchmarkGet	234110263	5.438 ns/op	0 B/op	0 allocs/op