feat(*): initial commit

internal/cache.go

@@ -0,0 +1,45 @@
+package internal
+
+import (
+	"sync"
+	"time"
+)
+
+type CacheItem[T any] struct {
+	item       T
+	imutex     sync.Mutex
+	expiry     time.Time
+	TTLSeconds uint
+	FetchFunc  func() (T, error)
+}
+
+func (c *CacheItem[T]) Get() (T, error) {
+	c.imutex.Lock()
+	defer c.imutex.Unlock()
+
+	if !c.expiry.After(time.Now()) {
+		c.expiry = time.Now().Add(time.Duration(c.TTLSeconds) * time.Second)
+
+		item, err := c.FetchFunc()
+		if err != nil {
+			return item, err
+		}
+
+		c.item = item
+	}
+
+	return c.item, nil
+}
+
+func (c *CacheItem[T]) Invalidate() {
+	c.imutex.Lock()
+	defer c.imutex.Unlock()
+	c.expiry = time.Now()
+}
+
+func NewCache[T any](fetchfunc func() (T, error), ttl uint) CacheItem[T] {
+	return CacheItem[T]{
+		TTLSeconds: ttl,
+		FetchFunc:  fetchfunc,
+	}
+}