Feature: add lazy for proxy group and provider

adapters/provider/healthcheck.go

@@ -5,6 +5,8 @@ import (
 	"time"
 
 	C "github.com/Dreamacro/clash/constant"
+
+	"go.uber.org/atomic"
 )
 
 const (
@@ -17,10 +19,12 @@ type HealthCheckOption struct {
 }
 
 type HealthCheck struct {
-	url      string
-	proxies  []C.Proxy
-	interval uint
-	done     chan struct{}
+	url       string
+	proxies   []C.Proxy
+	interval  uint
+	lazy      bool
+	lastTouch *atomic.Int64
+	done      chan struct{}
 }
 
 func (hc *HealthCheck) process() {
@@ -30,7 +34,10 @@ func (hc *HealthCheck) process() {
 	for {
 		select {
 		case <-ticker.C:
-			hc.check()
+			now := time.Now().Unix()
+			if !hc.lazy || now-hc.lastTouch.Load() < int64(hc.interval) {
+				hc.check()
+			}
 		case <-hc.done:
 			ticker.Stop()
 			return
@@ -46,6 +53,10 @@ func (hc *HealthCheck) auto() bool {
 	return hc.interval != 0
 }
 
+func (hc *HealthCheck) touch() {
+	hc.lastTouch.Store(time.Now().Unix())
+}
+
 func (hc *HealthCheck) check() {
 	ctx, cancel := context.WithTimeout(context.Background(), defaultURLTestTimeout)
 	for _, proxy := range hc.proxies {
@@ -60,11 +71,13 @@ func (hc *HealthCheck) close() {
 	hc.done <- struct{}{}
 }
 
-func NewHealthCheck(proxies []C.Proxy, url string, interval uint) *HealthCheck {
+func NewHealthCheck(proxies []C.Proxy, url string, interval uint, lazy bool) *HealthCheck {
 	return &HealthCheck{
-		proxies:  proxies,
-		url:      url,
-		interval: interval,
-		done:     make(chan struct{}, 1),
+		proxies:   proxies,
+		url:       url,
+		interval:  interval,
+		lazy:      lazy,
+		lastTouch: atomic.NewInt64(0),
+		done:      make(chan struct{}, 1),
 	}
 }

adapters/provider/parser.go

@@ -17,6 +17,7 @@ type healthCheckSchema struct {
 	Enable   bool   `provider:"enable"`
 	URL      string `provider:"url"`
 	Interval int    `provider:"interval"`
+	Lazy     bool   `provider:"lazy,omitempty"`
 }
 
 type proxyProviderSchema struct {
@@ -30,7 +31,11 @@ type proxyProviderSchema struct {
 func ParseProxyProvider(name string, mapping map[string]interface{}) (ProxyProvider, error) {
 	decoder := structure.NewDecoder(structure.Option{TagName: "provider", WeaklyTypedInput: true})
 
-	schema := &proxyProviderSchema{}
+	schema := &proxyProviderSchema{
+		HealthCheck: healthCheckSchema{
+			Lazy: true,
+		},
+	}
 	if err := decoder.Decode(mapping, schema); err != nil {
 		return nil, err
 	}
@@ -39,7 +44,7 @@ func ParseProxyProvider(name string, mapping map[string]interface{}) (ProxyProvi
 	if schema.HealthCheck.Enable {
 		hcInterval = uint(schema.HealthCheck.Interval)
 	}
-	hc := NewHealthCheck([]C.Proxy{}, schema.HealthCheck.URL, hcInterval)
+	hc := NewHealthCheck([]C.Proxy{}, schema.HealthCheck.URL, hcInterval, schema.HealthCheck.Lazy)
 
 	path := C.Path.Resolve(schema.Path)
 

adapters/provider/provider.go

@@ -50,6 +50,9 @@ type Provider interface {
 type ProxyProvider interface {
 	Provider
 	Proxies() []C.Proxy
+	// ProxiesWithTouch is used to inform the provider that the proxy is actually being used while getting the list of proxies.
+	// Commonly used in Dial and DialUDP
+	ProxiesWithTouch() []C.Proxy
 	HealthCheck()
 }
 
@@ -112,6 +115,11 @@ func (pp *proxySetProvider) Proxies() []C.Proxy {
 	return pp.proxies
 }
 
+func (pp *proxySetProvider) ProxiesWithTouch() []C.Proxy {
+	pp.healthCheck.touch()
+	return pp.Proxies()
+}
+
 func proxiesParse(buf []byte) (interface{}, error) {
 	schema := &ProxySchema{}
 
@@ -223,6 +231,11 @@ func (cp *compatibleProvider) Proxies() []C.Proxy {
 	return cp.proxies
 }
 
+func (cp *compatibleProvider) ProxiesWithTouch() []C.Proxy {
+	cp.healthCheck.touch()
+	return cp.Proxies()
+}
+
 func stopCompatibleProvider(pd *CompatibleProvider) {
 	pd.healthCheck.close()
 }