ttlmap-go

This is sync.Map with generics and automatic expiration of entries. It's useful for implementing time-bound caches.

Features:

Guarantees that entries live at least as long as a set timeout
Thread-safe (using Go's sync.Map internally)
Generics!
No dependencies
No close method, can be forgotten and GC'd anytime
No footguns, API cannot be misused
Full test coverage

This is yet another TTL map because existing implementations did not quite fit my need. If you need timeouts per item, then also check out mailgun's implementation! It takes a bit of a different approach, e.g. deletes on access or upon reaching a capacity limit.

Usage

import "github.com/mologie/ttlmap-go"

m := ttlmap.New[string, string](1 * time.Second)

m.Store("a", "foo")
time.Sleep(2 * time.Second)

m.Store("b", "bar")
time.Sleep(2 * time.Second)

if _, ok := m.Load("a"); ok {
	panic("unreachable")
} else {
	println("entry a does not exist, because b's write scheduled cleanup")
}

if _, ok := m.Load("b"); ok {
	println("entry b still exists despite having expired, because no write happened after it")
} else {
	panic("unreachable")
}

See cmd/ttlmap-demo/main.go for a more elaborate demo involving Reaper, which cleans up entries during periods without write activity.

License

This library is provided under the terms of the MIT license.