Go: A Simple TTL Cache Using time.AfterFunc()

cache_ttl.go

package cache

import (
	"sync"
	"time"
)

type Cache[K comparable, V any] interface {
	Set(K, V)
	Get(K) (V, bool)
	Remove(K)
}

type ttlCache[K comparable, V any] struct {
	items map[K]V
	ttl   time.Duration
	mu    sync.Mutex
}

func NewTtl[K comparable, V any](ttl time.Duration) Cache[K, V] {
	return &ttlCache[K, V]{
		items: make(map[K]V),
		ttl:   ttl,
	}
}

func (c *ttlCache[K, V]) Set(key K, value V) {
	c.mu.Lock()
	defer c.mu.Unlock()
	c.items[key] = value
	if c.ttl > 0 {
		time.AfterFunc(c.ttl, func() { c.Remove(key) })
	}
}

func (c *ttlCache[K, V]) Get(key K) (V, bool) {
	c.mu.Lock()
	defer c.mu.Unlock()
	v, ok := c.items[key]
	return v, ok
}

func (c *ttlCache[K, V]) Remove(key K) {
	c.mu.Lock()
	defer c.mu.Unlock()
	delete(c.items, key)
}

goos: darwin
goarch: arm64
pkg: github.com/cowork-ai/docugpt/cache
cpu: Apple M2 Pro
BenchmarkCacheSet-10           	 9296667	       158.8 ns/op	     106 B/op	       0 allocs/op
BenchmarkCacheSetWithTtl-10    	 1545234	       781.1 ns/op	     166 B/op	       2 allocs/op
PASS