Style: code style

adapter/outboundgroup/fallback.go

@@ -0,0 +1,100 @@
+package outboundgroup
+
+import (
+	"context"
+	"encoding/json"
+
+	"github.com/Dreamacro/clash/adapter/outbound"
+	"github.com/Dreamacro/clash/adapter/provider"
+	"github.com/Dreamacro/clash/common/singledo"
+	C "github.com/Dreamacro/clash/constant"
+)
+
+type Fallback struct {
+	*outbound.Base
+	disableUDP bool
+	single     *singledo.Single
+	providers  []provider.ProxyProvider
+}
+
+func (f *Fallback) Now() string {
+	proxy := f.findAliveProxy(false)
+	return proxy.Name()
+}
+
+// DialContext implements C.ProxyAdapter
+func (f *Fallback) DialContext(ctx context.Context, metadata *C.Metadata) (C.Conn, error) {
+	proxy := f.findAliveProxy(true)
+	c, err := proxy.DialContext(ctx, metadata)
+	if err == nil {
+		c.AppendToChains(f)
+	}
+	return c, err
+}
+
+// DialUDP implements C.ProxyAdapter
+func (f *Fallback) DialUDP(metadata *C.Metadata) (C.PacketConn, error) {
+	proxy := f.findAliveProxy(true)
+	pc, err := proxy.DialUDP(metadata)
+	if err == nil {
+		pc.AppendToChains(f)
+	}
+	return pc, err
+}
+
+// SupportUDP implements C.ProxyAdapter
+func (f *Fallback) SupportUDP() bool {
+	if f.disableUDP {
+		return false
+	}
+
+	proxy := f.findAliveProxy(false)
+	return proxy.SupportUDP()
+}
+
+// MarshalJSON implements C.ProxyAdapter
+func (f *Fallback) MarshalJSON() ([]byte, error) {
+	var all []string
+	for _, proxy := range f.proxies(false) {
+		all = append(all, proxy.Name())
+	}
+	return json.Marshal(map[string]interface{}{
+		"type": f.Type().String(),
+		"now":  f.Now(),
+		"all":  all,
+	})
+}
+
+// Unwrap implements C.ProxyAdapter
+func (f *Fallback) Unwrap(metadata *C.Metadata) C.Proxy {
+	proxy := f.findAliveProxy(true)
+	return proxy
+}
+
+func (f *Fallback) proxies(touch bool) []C.Proxy {
+	elm, _, _ := f.single.Do(func() (interface{}, error) {
+		return getProvidersProxies(f.providers, touch), nil
+	})
+
+	return elm.([]C.Proxy)
+}
+
+func (f *Fallback) findAliveProxy(touch bool) C.Proxy {
+	proxies := f.proxies(touch)
+	for _, proxy := range proxies {
+		if proxy.Alive() {
+			return proxy
+		}
+	}
+
+	return proxies[0]
+}
+
+func NewFallback(options *GroupCommonOption, providers []provider.ProxyProvider) *Fallback {
+	return &Fallback{
+		Base:       outbound.NewBase(options.Name, "", C.Fallback, false),
+		single:     singledo.NewSingle(defaultGetProxiesDuration),
+		providers:  providers,
+		disableUDP: options.DisableUDP,
+	}
+}