Files
arbeitszeitmessung/Backend/helper/system.go
2025-03-28 08:23:52 +01:00

54 lines
956 B
Go

package helper
import (
"os"
"time"
)
// Returns env with default fallback value.
//
// Params:
//
// key - enviroment var name
// fallback - default value
func GetEnv(key, fallback string) string {
if value, ok := os.LookupEnv(key); ok {
return value
}
return fallback
}
type CacheItem struct {
value any
expiration time.Time
}
type Cache struct {
data map[string]CacheItem
ttl time.Duration
fetch func(key string) (any, error)
}
func NewCache(ttl time.Duration, fetchFunc func(key string) (any, error)) *Cache {
return &Cache{
data: make(map[string]CacheItem),
ttl: ttl,
fetch: fetchFunc,
}
}
func (c *Cache) Get(key string) (any, error) {
if item, found := c.data[key]; found {
if time.Now().Before(item.expiration) {
return item.value, nil
}
}
value, err := c.fetch(key)
if err != nil {
return nil, err
}
c.data[key] = CacheItem{value: value, expiration: time.Now().Add(c.ttl)}
return value, nil
}