Change: proxy gruop strategy improvement

adapters/outboundgroup/urltest.go

@@ -4,36 +4,35 @@ import (
 	"context"
 	"encoding/json"
 	"net"
+	"time"
 
 	"github.com/Dreamacro/clash/adapters/outbound"
 	"github.com/Dreamacro/clash/adapters/provider"
+	"github.com/Dreamacro/clash/common/singledo"
 	C "github.com/Dreamacro/clash/constant"
 )
 
 type URLTest struct {
 	*outbound.Base
-	fast      C.Proxy
-	providers []provider.ProxyProvider
+	single     *singledo.Single
+	fastSingle *singledo.Single
+	providers  []provider.ProxyProvider
 }
 
 func (u *URLTest) Now() string {
-	return u.fast.Name()
+	return u.fast().Name()
 }
 
 func (u *URLTest) DialContext(ctx context.Context, metadata *C.Metadata) (c C.Conn, err error) {
-	for i := 0; i < 3; i++ {
-		c, err = u.fast.DialContext(ctx, metadata)
-		if err == nil {
-			c.AppendToChains(u)
-			return
-		}
-		u.fallback()
+	c, err = u.fast().DialContext(ctx, metadata)
+	if err == nil {
+		c.AppendToChains(u)
 	}
-	return
+	return c, err
 }
 
 func (u *URLTest) DialUDP(metadata *C.Metadata) (C.PacketConn, net.Addr, error) {
-	pc, addr, err := u.fast.DialUDP(metadata)
+	pc, addr, err := u.fast().DialUDP(metadata)
 	if err == nil {
 		pc.AppendToChains(u)
 	}
@@ -41,15 +40,37 @@ func (u *URLTest) DialUDP(metadata *C.Metadata) (C.PacketConn, net.Addr, error)
 }
 
 func (u *URLTest) proxies() []C.Proxy {
-	proxies := []C.Proxy{}
-	for _, provider := range u.providers {
-		proxies = append(proxies, provider.Proxies()...)
-	}
-	return proxies
+	elm, _, _ := u.single.Do(func() (interface{}, error) {
+		return getProvidersProxies(u.providers), nil
+	})
+
+	return elm.([]C.Proxy)
+}
+
+func (u *URLTest) fast() C.Proxy {
+	elm, _, _ := u.fastSingle.Do(func() (interface{}, error) {
+		proxies := u.proxies()
+		fast := proxies[0]
+		min := fast.LastDelay()
+		for _, proxy := range proxies[1:] {
+			if !proxy.Alive() {
+				continue
+			}
+
+			delay := proxy.LastDelay()
+			if delay < min {
+				fast = proxy
+				min = delay
+			}
+		}
+		return fast, nil
+	})
+
+	return elm.(C.Proxy)
 }
 
 func (u *URLTest) SupportUDP() bool {
-	return u.fast.SupportUDP()
+	return u.fast().SupportUDP()
 }
 
 func (u *URLTest) MarshalJSON() ([]byte, error) {
@@ -64,30 +85,11 @@ func (u *URLTest) MarshalJSON() ([]byte, error) {
 	})
 }
 
-func (u *URLTest) fallback() {
-	proxies := u.proxies()
-	fast := proxies[0]
-	min := fast.LastDelay()
-	for _, proxy := range proxies[1:] {
-		if !proxy.Alive() {
-			continue
-		}
-
-		delay := proxy.LastDelay()
-		if delay < min {
-			fast = proxy
-			min = delay
-		}
-	}
-	u.fast = fast
-}
-
 func NewURLTest(name string, providers []provider.ProxyProvider) *URLTest {
-	fast := providers[0].Proxies()[0]
-
 	return &URLTest{
-		Base:      outbound.NewBase(name, C.URLTest, false),
-		fast:      fast,
-		providers: providers,
+		Base:       outbound.NewBase(name, C.URLTest, false),
+		single:     singledo.NewSingle(defaultGetProxiesDuration),
+		fastSingle: singledo.NewSingle(time.Second * 10),
+		providers:  providers,
 	}
 }