package server import ( "fmt" "sync" "time" "github.com/mitchellh/colorstring" "github.com/pterodactyl/wings/config" "github.com/pterodactyl/wings/system" ) // appName is a local cache variable to avoid having to make expensive copies of // the configuration every time we need to send output along to the websocket for // a server. var appName string var appNameSync sync.Once // PublishConsoleOutputFromDaemon sends output to the server console formatted // to appear correctly as being sent from Wings. func (s *Server) PublishConsoleOutputFromDaemon(data string) { appNameSync.Do(func() { appName = config.Get().AppName }) s.Events().Publish( ConsoleOutputEvent, colorstring.Color(fmt.Sprintf("[yellow][bold][%s Daemon]:[default] %s", appName, data)), ) } // Throttler returns the throttler instance for the server or creates a new one. func (s *Server) Throttler() *ConsoleThrottle { s.throttleOnce.Do(func() { throttles := config.Get().Throttles period := time.Duration(throttles.Period) * time.Millisecond s.throttler = newConsoleThrottle(throttles.Lines, period) s.throttler.strike = func() { s.PublishConsoleOutputFromDaemon("Server is outputting console data too quickly -- throttling...") } }) return s.throttler } type ConsoleThrottle struct { limit *system.Rate lock *system.Locker strike func() } func newConsoleThrottle(lines uint64, period time.Duration) *ConsoleThrottle { return &ConsoleThrottle{ limit: system.NewRate(lines, period), lock: system.NewLocker(), } } // Allow checks if the console is allowed to process more output data, or if too // much has already been sent over the line. If there is too much output the // strike callback function is triggered, but only if it has not already been // triggered at this point in the process. // // If output is allowed, the lock on the throttler is released and the next time // it is triggered the strike function will be re-executed. func (ct *ConsoleThrottle) Allow() bool { if !ct.limit.Try() { if err := ct.lock.Acquire(); err == nil { if ct.strike != nil { ct.strike() } } return false } ct.lock.Release() return true } // Reset resets the console throttler internal rate limiter and overage counter. func (ct *ConsoleThrottle) Reset() { ct.limit.Reset() }