1 files changed, 126 insertions, 0 deletions
diff --git a/pkg/server/hook/hook.go b/pkg/server/hook/hook.go
new file mode 100644
index 0000000..b2970ac
--- /dev/null
+++ b/pkg/server/hook/hook.go
@@ -0,0 +1,126 @@
+package hook
+
+import (
+	"fmt"
+	"log"
+	"sort"
+	"strings"
+	"tunnel/pkg/server/env"
+	"tunnel/pkg/server/opts"
+	"tunnel/pkg/server/queue"
+)
+
+type hookInitFunc func(opts.Opts, env.Env) (hook, error)
+
+var hooks = map[string]hookInitFunc{}
+
+type hook interface {
+	Open(env env.Env) (interface{}, error)
+}
+
+type H interface {
+	hook
+	String() string
+}
+
+type Sender interface {
+	Send(rq, wq queue.Q) error
+}
+
+type Recver interface {
+	Recv(rq, wq queue.Q) error
+}
+
+type Func func(rq, wq queue.Q) error
+
+func (f Func) Send(rq, wq queue.Q) error {
+	return f(rq, wq)
+}
+
+func (f Func) Open(env env.Env) (interface{}, error) {
+	return f, nil
+}
+
+type wrapper struct {
+	hook
+	name    string
+	reverse bool
+}
+
+func (w *wrapper) String() string {
+	return fmt.Sprintf("hook:%s", w.name)
+}
+
+func Open(h H, env env.Env) (Func, Func, error) {
+	var send, recv Func
+
+	w := h.(*wrapper)
+
+	it, err := h.Open(env)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	if sender, ok := it.(Sender); ok {
+		send = sender.Send
+	}
+
+	if recver, ok := it.(Recver); ok {
+		recv = recver.Recv
+	}
+
+	if w.reverse {
+		send, recv = recv, send
+	}
+
+	return send, recv, nil
+}
+
+func New(desc string, env env.Env) (H, error) {
+	name, opts := opts.Parse(desc)
+	reverse := false
+
+	if strings.HasPrefix(name, "-") {
+		name = name[1:]
+		reverse = true
+	}
+
+	if f, ok := hooks[name]; !ok {
+		return nil, fmt.Errorf("unknown hook '%s'", name)
+	} else if h, err := f(opts, env); err != nil {
+		return nil, err
+	} else {
+		w := &wrapper{
+			hook:    h,
+			name:    name,
+			reverse: reverse,
+		}
+		return w, nil
+	}
+}
+
+func register(name string, f hookInitFunc) {
+	if _, ok := hooks[name]; ok {
+		log.Panicf("duplicate hook name '%s'", name)
+	}
+
+	hooks[name] = f
+}
+
+func registerFunc(name string, p Func) {
+	register(name, func(opts.Opts, env.Env) (hook, error) {
+		return p, nil
+	})
+}
+
+func GetList() []string {
+	var list []string
+
+	for k := range hooks {
+		list = append(list, k)
+	}
+
+	sort.Strings(list)
+
+	return list
+}