ilk

svc/queries/currency_cache.go

@@ -0,0 +1,64 @@
+package queries
+
+import (
+	"bssapp-backend/models"
+	"database/sql"
+	"sync"
+	"time"
+)
+
+/* ===============================
+   CACHE STRUCT
+================================ */
+
+type currencyCacheItem struct {
+	data      *models.TodayCurrencyV3
+	expiresAt time.Time
+}
+
+var (
+	currencyCache = make(map[string]currencyCacheItem)
+	cacheMutex    sync.RWMutex
+	cacheTTL      = 5 * time.Minute
+)
+
+/* ===============================
+   MAIN CACHE FUNC
+================================ */
+
+func GetCachedCurrencyV3(db *sql.DB, code string) (*models.TodayCurrencyV3, error) {
+
+	now := time.Now()
+
+	/* ---------- READ CACHE ---------- */
+	cacheMutex.RLock()
+
+	item, ok := currencyCache[code]
+
+	if ok && now.Before(item.expiresAt) {
+		cacheMutex.RUnlock()
+		return item.data, nil
+	}
+
+	cacheMutex.RUnlock()
+
+	/* ---------- FETCH DB ---------- */
+
+	data, err := GetTodayCurrencyV3(db, code)
+	if err != nil {
+		return nil, err
+	}
+
+	/* ---------- WRITE CACHE ---------- */
+
+	cacheMutex.Lock()
+
+	currencyCache[code] = currencyCacheItem{
+		data:      data,
+		expiresAt: now.Add(cacheTTL),
+	}
+
+	cacheMutex.Unlock()
+
+	return data, nil
+}