add observer

handler/option.go

@@ -11,6 +11,7 @@ import (
 	"github.com/go-gost/core/limiter/traffic"
 	"github.com/go-gost/core/logger"
 	"github.com/go-gost/core/metadata"
+	"github.com/go-gost/core/observer"
 )
 
 type Options struct {
@@ -22,6 +23,7 @@ type Options struct {
 	Limiter     traffic.TrafficLimiter
 	TLSConfig   *tls.Config
 	Logger      logger.Logger
+	Observer observer.Observer
 	Service     string
 }
 
@@ -75,6 +77,12 @@ func LoggerOption(logger logger.Logger) Option {
 	}
 }
 
+func ObserverOption(observer observer.Observer) Option {
+	return func(opts *Options) {
+		opts.Observer = observer
+	}
+}
+
 func ServiceOption(service string) Option {
 	return func(opts *Options) {
 		opts.Service = service

listener/option.go

@@ -10,6 +10,7 @@ import (
 	"github.com/go-gost/core/limiter/conn"
 	"github.com/go-gost/core/limiter/traffic"
 	"github.com/go-gost/core/logger"
+	"github.com/go-gost/x/stats"
 )
 
 type Options struct {
@@ -21,6 +22,7 @@ type Options struct {
 	TrafficLimiter traffic.TrafficLimiter
 	ConnLimiter    conn.ConnLimiter
 	Chain          chain.Chainer
+	Stats          *stats.Stats
 	Logger         logger.Logger
 	Service        string
 	ProxyProtocol  int
@@ -76,6 +78,12 @@ func ChainOption(chain chain.Chainer) Option {
 	}
 }
 
+func StatsOption(stats *stats.Stats) Option {
+	return func(opts *Options) {
+		opts.Stats = stats
+	}
+}
+
 func LoggerOption(logger logger.Logger) Option {
 	return func(opts *Options) {
 		opts.Logger = logger

observer/observer.go

@@ -0,0 +1,22 @@
+package observer
+
+import "context"
+
+type Options struct{}
+
+type Option func(opts *Options)
+
+type Observer interface {
+	Observe(ctx context.Context, events []Event, opts ...Option) error
+}
+
+type EventType string
+
+const (
+	EventStatus EventType = "status"
+	EventStats  EventType = "stats"
+)
+
+type Event interface {
+	Type() EventType
+}