package beego import ( "errors" "fmt" "strconv" "sync" "time" ) var ( DefaultEvery int = 60 // 1 minute ) type BeeItem struct { val interface{} Lastaccess time.Time expired int } func (itm *BeeItem) Access() interface{} { itm.Lastaccess = time.Now() return itm.val } type BeeCache struct { lock sync.RWMutex dur time.Duration items map[string]*BeeItem Every int // Run an expiration check Every seconds } // NewDefaultCache returns a new FileCache with sane defaults. func NewBeeCache() *BeeCache { cache := BeeCache{dur: time.Since(time.Now()), Every: DefaultEvery} return &cache } func (bc *BeeCache) Get(name string) interface{} { bc.lock.RLock() defer bc.lock.RUnlock() itm, ok := bc.items[name] if !ok { return nil } return itm.Access() } func (bc *BeeCache) Put(name string, value interface{}, expired int) error { bc.lock.Lock() defer bc.lock.Unlock() t := BeeItem{val: value, Lastaccess: time.Now(), expired: expired} if _, ok := bc.items[name]; ok { return errors.New("the key is exist") } else { bc.items[name] = &t } return nil } func (bc *BeeCache) Delete(name string) (ok bool, err error) { bc.lock.Lock() defer bc.lock.Unlock() if _, ok = bc.items[name]; !ok { return } delete(bc.items, name) _, valid := bc.items[name] if valid { ok = false } return } func (bc *BeeCache) IsExist(name string) bool { bc.lock.RLock() defer bc.lock.RUnlock() _, ok := bc.items[name] return ok } // Start activates the file cache; it will func (bc *BeeCache) Start() error { dur, err := time.ParseDuration(fmt.Sprintf("%ds", bc.Every)) if err != nil { return err } bc.dur = dur bc.items = make(map[string]*BeeItem, 0) go bc.vaccuum() return nil } func (bc *BeeCache) vaccuum() { if bc.Every < 1 { return } for { <-time.After(time.Duration(bc.dur)) if bc.items == nil { return } for name, _ := range bc.items { bc.item_expired(name) } } } // item_expired returns true if an item is expired. func (bc *BeeCache) item_expired(name string) bool { bc.lock.Lock() defer bc.lock.Unlock() itm, ok := bc.items[name] if !ok { return true } dur := time.Now().Sub(itm.Lastaccess) sec, err := strconv.Atoi(fmt.Sprintf("%0.0f", dur.Seconds())) if err != nil { delete(bc.items, name) return true } else if sec >= itm.expired { delete(bc.items, name) return true } return false }
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