package server import ( "golang.org/x/time/rate" "heckel.io/ntfy/util" "sync" "time" ) const ( visitorExpungeAfter = 30 * time.Minute ) // visitor represents an API user, and its associated rate.Limiter used for rate limiting type visitor struct { config *Config limiter *rate.Limiter subscriptions *util.Limiter seen time.Time mu sync.Mutex } func newVisitor(conf *Config) *visitor { return &visitor{ config: conf, limiter: rate.NewLimiter(rate.Every(conf.VisitorRequestLimitReplenish), conf.VisitorRequestLimitBurst), subscriptions: util.NewLimiter(int64(conf.VisitorSubscriptionLimit)), seen: time.Now(), } } func (v *visitor) RequestAllowed() error { if !v.limiter.Allow() { return errHTTPTooManyRequests } return nil } func (v *visitor) AddSubscription() error { v.mu.Lock() defer v.mu.Unlock() if err := v.subscriptions.Add(1); err != nil { return errHTTPTooManyRequests } return nil } func (v *visitor) RemoveSubscription() { v.mu.Lock() defer v.mu.Unlock() v.subscriptions.Sub(1) } func (v *visitor) Keepalive() { v.mu.Lock() defer v.mu.Unlock() v.seen = time.Now() } func (v *visitor) Stale() bool { v.mu.Lock() defer v.mu.Unlock() return time.Since(v.seen) > visitorExpungeAfter }