From 8923159aee77fe9723628c76e73e3d04cdcdd03c Mon Sep 17 00:00:00 2001
From: Darien Raymond <admin@v2ray.com>
Date: Wed, 24 Jan 2018 15:05:46 +0100
Subject: [PATCH] commander interface

---
 commander.go | 63 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 v2ray.go     | 10 +++++++++
 2 files changed, 73 insertions(+)
 create mode 100644 commander.go

diff --git a/commander.go b/commander.go
new file mode 100644
index 000000000..f65f0072f
--- /dev/null
+++ b/commander.go
@@ -0,0 +1,63 @@
+package core
+
+import (
+	"sync"
+
+	"google.golang.org/grpc"
+)
+
+// ServiceRegistryCallback is a callback function for registering services.
+type ServiceRegistryCallback func(s *grpc.Server)
+
+// Commander is a feature that accepts commands from external source.
+type Commander interface {
+	Feature
+
+	// RegisterService registers a service into this Commander.
+	RegisterService(ServiceRegistryCallback)
+}
+
+type syncCommander struct {
+	sync.RWMutex
+	Commander
+}
+
+func (c *syncCommander) RegisterService(callback ServiceRegistryCallback) {
+	c.RLock()
+	defer c.RUnlock()
+
+	if c.Commander == nil {
+		return
+	}
+
+	c.Commander.RegisterService(callback)
+}
+
+func (c *syncCommander) Start() error {
+	c.RLock()
+	defer c.RUnlock()
+
+	if c.Commander == nil {
+		return nil
+	}
+
+	return c.Commander.Start()
+}
+
+func (c *syncCommander) Close() {
+	c.RLock()
+	defer c.RUnlock()
+
+	if c.Commander == nil {
+		return
+	}
+
+	c.Commander.Close()
+}
+
+func (c *syncCommander) Set(commander Commander) {
+	c.Lock()
+	defer c.Unlock()
+
+	c.Commander = commander
+}
diff --git a/v2ray.go b/v2ray.go
index b6a0de9d4..542deef8a 100644
--- a/v2ray.go
+++ b/v2ray.go
@@ -28,6 +28,7 @@ type Instance struct {
 	ihm           syncInboundHandlerManager
 	ohm           syncOutboundHandlerManager
 	clock         syncClock
+	cmd           syncCommander
 
 	features []Feature
 	id       uuid.UUID
@@ -130,6 +131,10 @@ func (s *Instance) RegisterFeature(feature interface{}, instance Feature) error
 		s.ihm.Set(instance.(InboundHandlerManager))
 	case OutboundHandlerManager, *OutboundHandlerManager:
 		s.ohm.Set(instance.(OutboundHandlerManager))
+	case Clock, *Clock:
+		s.clock.Set(instance.(Clock))
+	case Commander, *Commander:
+		s.cmd.Set(instance.(Commander))
 	}
 	s.features = append(s.features, instance)
 	return nil
@@ -169,3 +174,8 @@ func (s *Instance) OutboundHandlerManager() OutboundHandlerManager {
 func (s *Instance) Clock() Clock {
 	return &(s.clock)
 }
+
+// Commander returns the Commander used by this Instance. The returned Commander is always functional.
+func (s *Instance) Commander() Commander {
+	return &(s.cmd)
+}