massive refactoring for interoperability

router.go

@@ -0,0 +1,118 @@
+package core
+
+import (
+	"context"
+	"sync"
+
+	"v2ray.com/core/common/errors"
+	"v2ray.com/core/common/net"
+	"v2ray.com/core/transport/ray"
+)
+
+// Dispatcher is a feature that dispatches inbound requests to outbound handlers based on rules.
+// Dispatcher is required to be registered in a V2Ray instance to make V2Ray function properly.
+type Dispatcher interface {
+	Feature
+
+	// Dispatch returns a Ray for transporting data for the given request.
+	Dispatch(ctx context.Context, dest net.Destination) (ray.InboundRay, error)
+}
+
+type syncDispatcher struct {
+	sync.RWMutex
+	Dispatcher
+}
+
+func (d *syncDispatcher) Dispatch(ctx context.Context, dest net.Destination) (ray.InboundRay, error) {
+	d.RLock()
+	defer d.RUnlock()
+
+	if d.Dispatcher == nil {
+		return nil, newError("Dispatcher not set.").AtError()
+	}
+
+	return d.Dispatcher.Dispatch(ctx, dest)
+}
+
+func (d *syncDispatcher) Start() error {
+	d.RLock()
+	defer d.RUnlock()
+
+	if d.Dispatcher == nil {
+		return newError("Dispatcher not set.").AtError()
+	}
+
+	return d.Dispatcher.Start()
+}
+
+func (d *syncDispatcher) Close() {
+	d.RLock()
+	defer d.RUnlock()
+
+	if d.Dispatcher != nil {
+		d.Dispatcher.Close()
+	}
+}
+
+func (d *syncDispatcher) Set(disp Dispatcher) {
+	d.Lock()
+	defer d.Unlock()
+
+	d.Dispatcher = disp
+}
+
+var (
+	// ErrNoClue is for the situation that existing information is not enough to make a decision. For example, Router may return this error when there is no suitable route.
+	ErrNoClue = errors.New("not enough information for making a decision")
+)
+
+// Router is a feature to choose a outbound tag for the given request.
+type Router interface {
+	Feature
+
+	// PickRoute returns a tag of an OutboundHandler based on the given context.
+	PickRoute(ctx context.Context) (string, error)
+}
+
+type syncRouter struct {
+	sync.RWMutex
+	Router
+}
+
+func (r *syncRouter) PickRoute(ctx context.Context) (string, error) {
+	r.RLock()
+	defer r.RUnlock()
+
+	if r.Router == nil {
+		return "", ErrNoClue
+	}
+
+	return r.Router.PickRoute(ctx)
+}
+
+func (r *syncRouter) Start() error {
+	r.RLock()
+	defer r.RUnlock()
+
+	if r.Router == nil {
+		return nil
+	}
+
+	return r.Router.Start()
+}
+
+func (r *syncRouter) Close() {
+	r.RLock()
+	defer r.RUnlock()
+
+	if r.Router != nil {
+		r.Router.Close()
+	}
+}
+
+func (r *syncRouter) Set(router Router) {
+	r.Lock()
+	defer r.Unlock()
+
+	r.Router = router
+}