package stats //go:generate errorgen import ( "context" "v2ray.com/core/common" "v2ray.com/core/features" ) // Counter is the interface for stats counters. // // v2ray:api:stable type Counter interface { // Value is the current value of the counter. Value() int64 // Set sets a new value to the counter, and returns the previous one. Set(int64) int64 // Add adds a value to the current counter value, and returns the previous value. Add(int64) int64 } // Channel is the interface for stats channel. // // v2ray:api:stable type Channel interface { // Channel is a runnable unit. common.Runnable // Publish broadcasts a message through the channel with a controlling context. Publish(context.Context, interface{}) // SubscriberCount returns the number of the subscribers. Subscribers() []chan interface{} // Subscribe registers for listening to channel stream and returns a new listener channel. Subscribe() (chan interface{}, error) // Unsubscribe unregisters a listener channel from current Channel object. Unsubscribe(chan interface{}) error } // SubscribeRunnableChannel subscribes the channel and starts it if there is first subscriber coming. func SubscribeRunnableChannel(c Channel) (chan interface{}, error) { if len(c.Subscribers()) == 0 { if err := c.Start(); err != nil { return nil, err } } return c.Subscribe() } // UnsubscribeClosableChannel unsubcribes the channel and close it if there is no more subscriber. func UnsubscribeClosableChannel(c Channel, sub chan interface{}) error { if err := c.Unsubscribe(sub); err != nil { return err } if len(c.Subscribers()) == 0 { return c.Close() } return nil } // Manager is the interface for stats manager. // // v2ray:api:stable type Manager interface { features.Feature // RegisterCounter registers a new counter to the manager. The identifier string must not be empty, and unique among other counters. RegisterCounter(string) (Counter, error) // UnregisterCounter unregisters a counter from the manager by its identifier. UnregisterCounter(string) error // GetCounter returns a counter by its identifier. GetCounter(string) Counter // RegisterChannel registers a new channel to the manager. The identifier string must not be empty, and unique among other channels. RegisterChannel(string) (Channel, error) // UnregisterCounter unregisters a channel from the manager by its identifier. UnregisterChannel(string) error // GetChannel returns a channel by its identifier. GetChannel(string) Channel } // GetOrRegisterCounter tries to get the StatCounter first. If not exist, it then tries to create a new counter. func GetOrRegisterCounter(m Manager, name string) (Counter, error) { counter := m.GetCounter(name) if counter != nil { return counter, nil } return m.RegisterCounter(name) } // GetOrRegisterChannel tries to get the StatChannel first. If not exist, it then tries to create a new channel. func GetOrRegisterChannel(m Manager, name string) (Channel, error) { channel := m.GetChannel(name) if channel != nil { return channel, nil } return m.RegisterChannel(name) } // ManagerType returns the type of Manager interface. Can be used to implement common.HasType. // // v2ray:api:stable func ManagerType() interface{} { return (*Manager)(nil) } // NoopManager is an implementation of Manager, which doesn't has actual functionalities. type NoopManager struct{} // Type implements common.HasType. func (NoopManager) Type() interface{} { return ManagerType() } // RegisterCounter implements Manager. func (NoopManager) RegisterCounter(string) (Counter, error) { return nil, newError("not implemented") } // UnregisterCounter implements Manager. func (NoopManager) UnregisterCounter(string) error { return nil } // GetCounter implements Manager. func (NoopManager) GetCounter(string) Counter { return nil } // RegisterChannel implements Manager. func (NoopManager) RegisterChannel(string) (Channel, error) { return nil, newError("not implemented") } // UnregisterChannel implements Manager. func (NoopManager) UnregisterChannel(string) error { return nil } // GetChannel implements Manager. func (NoopManager) GetChannel(string) Channel { return nil } // Start implements common.Runnable. func (NoopManager) Start() error { return nil } // Close implements common.Closable. func (NoopManager) Close() error { return nil }