Go Test

backend/go/internal/service/cache.go

@@ -0,0 +1,44 @@
+package service
+
+import (
+	"sync"
+	"time"
+)
+
+type Cache struct {
+	mu    sync.RWMutex
+	items map[string]cacheItem
+}
+
+type cacheItem struct {
+	value     any
+	expiresAt time.Time
+}
+
+func NewCache() *Cache {
+	return &Cache{items: make(map[string]cacheItem)}
+}
+
+func GetOrLoad[T any](cache *Cache, key string, ttl time.Duration, loader func() (T, error)) (T, error) {
+	var zero T
+
+	cache.mu.RLock()
+	item, ok := cache.items[key]
+	cache.mu.RUnlock()
+	if ok && (item.expiresAt.IsZero() || item.expiresAt.After(time.Now())) {
+		if value, castOK := item.value.(T); castOK {
+			return value, nil
+		}
+	}
+
+	value, err := loader()
+	if err != nil {
+		return zero, err
+	}
+
+	cache.mu.Lock()
+	cache.items[key] = cacheItem{value: value, expiresAt: time.Now().Add(ttl)}
+	cache.mu.Unlock()
+
+	return value, nil
+}