feat: docs api design

pkg/utils/cache.go

@@ -0,0 +1,50 @@
+package utils
+
+import (
+	"sync"
+	"time"
+)
+
+type Cache[T any] struct {
+	storage map[string]T
+	ttl     map[string]time.Time
+	mu      sync.RWMutex
+}
+
+func NewCache[T any]() *Cache[T] {
+	return &Cache[T]{
+		storage: make(map[string]T),
+		ttl:     make(map[string]time.Time),
+		mu:      sync.RWMutex{},
+	}
+}
+
+func (c *Cache[T]) Get(key string, ttl time.Duration, fn func() (T, error)) (T, error) {
+	c.mu.RLock()
+	if v, ok := c.storage[key]; ok {
+		if time.Now().Before(c.ttl[key]) {
+			c.mu.RUnlock()
+			return v, nil
+		}
+	}
+	c.mu.RUnlock()
+
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	if v, ok := c.storage[key]; ok {
+		if time.Now().Before(c.ttl[key]) {
+			return v, nil
+		}
+		delete(c.storage, key)
+		delete(c.ttl, key)
+	}
+
+	v, err := fn()
+	if err != nil {
+		return v, err
+	}
+	c.storage[key] = v
+	c.ttl[key] = time.Now().Add(ttl)
+	return v, nil
+}