package eventbus import ( "reflect" "strings" "github.com/libp2p/go-libp2p/p2p/metricshelper" "github.com/prometheus/client_golang/prometheus" ) const metricNamespace = "libp2p_eventbus" var ( eventsEmitted = prometheus.NewCounterVec( prometheus.CounterOpts{ Namespace: metricNamespace, Name: "events_emitted_total", Help: "Events Emitted", }, []string{"event"}, ) totalSubscribers = prometheus.NewGaugeVec( prometheus.GaugeOpts{ Namespace: metricNamespace, Name: "subscribers_total", Help: "Number of subscribers for an event type", }, []string{"event"}, ) subscriberQueueLength = prometheus.NewGaugeVec( prometheus.GaugeOpts{ Namespace: metricNamespace, Name: "subscriber_queue_length", Help: "Subscriber queue length", }, []string{"subscriber_name"}, ) subscriberQueueFull = prometheus.NewGaugeVec( prometheus.GaugeOpts{ Namespace: metricNamespace, Name: "subscriber_queue_full", Help: "Subscriber Queue completely full", }, []string{"subscriber_name"}, ) subscriberEventQueued = prometheus.NewCounterVec( prometheus.CounterOpts{ Namespace: metricNamespace, Name: "subscriber_event_queued", Help: "Event Queued for subscriber", }, []string{"subscriber_name"}, ) collectors = []prometheus.Collector{ eventsEmitted, totalSubscribers, subscriberQueueLength, subscriberQueueFull, subscriberEventQueued, } ) // MetricsTracer tracks metrics for the eventbus subsystem type MetricsTracer interface { // EventEmitted counts the total number of events grouped by event type EventEmitted(typ reflect.Type) // AddSubscriber adds a subscriber for the event type AddSubscriber(typ reflect.Type) // RemoveSubscriber removes a subscriber for the event type RemoveSubscriber(typ reflect.Type) // SubscriberQueueLength is the length of the subscribers channel SubscriberQueueLength(name string, n int) // SubscriberQueueFull tracks whether a subscribers channel if full SubscriberQueueFull(name string, isFull bool) // SubscriberEventQueued counts the total number of events grouped by subscriber SubscriberEventQueued(name string) } type metricsTracer struct{} var _ MetricsTracer = &metricsTracer{} type metricsTracerSetting struct { reg prometheus.Registerer } type MetricsTracerOption func(*metricsTracerSetting) func WithRegisterer(reg prometheus.Registerer) MetricsTracerOption { return func(s *metricsTracerSetting) { if reg != nil { s.reg = reg } } } func NewMetricsTracer(opts ...MetricsTracerOption) MetricsTracer { setting := &metricsTracerSetting{reg: prometheus.DefaultRegisterer} for _, opt := range opts { opt(setting) } metricshelper.RegisterCollectors(setting.reg, collectors...) return &metricsTracer{} } func (m *metricsTracer) EventEmitted(typ reflect.Type) { tags := metricshelper.GetStringSlice() defer metricshelper.PutStringSlice(tags) *tags = append(*tags, strings.TrimPrefix(typ.String(), "event.")) eventsEmitted.WithLabelValues(*tags...).Inc() } func (m *metricsTracer) AddSubscriber(typ reflect.Type) { tags := metricshelper.GetStringSlice() defer metricshelper.PutStringSlice(tags) *tags = append(*tags, strings.TrimPrefix(typ.String(), "event.")) totalSubscribers.WithLabelValues(*tags...).Inc() } func (m *metricsTracer) RemoveSubscriber(typ reflect.Type) { tags := metricshelper.GetStringSlice() defer metricshelper.PutStringSlice(tags) *tags = append(*tags, strings.TrimPrefix(typ.String(), "event.")) totalSubscribers.WithLabelValues(*tags...).Dec() } func (m *metricsTracer) SubscriberQueueLength(name string, n int) { tags := metricshelper.GetStringSlice() defer metricshelper.PutStringSlice(tags) *tags = append(*tags, name) subscriberQueueLength.WithLabelValues(*tags...).Set(float64(n)) } func (m *metricsTracer) SubscriberQueueFull(name string, isFull bool) { tags := metricshelper.GetStringSlice() defer metricshelper.PutStringSlice(tags) *tags = append(*tags, name) observer := subscriberQueueFull.WithLabelValues(*tags...) if isFull { observer.Set(1) } else { observer.Set(0) } } func (m *metricsTracer) SubscriberEventQueued(name string) { tags := metricshelper.GetStringSlice() defer metricshelper.PutStringSlice(tags) *tags = append(*tags, name) subscriberEventQueued.WithLabelValues(*tags...).Inc() }