From e0c07146dc6f0dcf95dd18ee8df423cfa5bc9e3d Mon Sep 17 00:00:00 2001
From: nadoo <287492+nadoo@users.noreply.github.com>
Date: Sun, 12 Aug 2018 22:00:12 +0800
Subject: [PATCH] strategy: do not check forwarders whose priority less than
 current value

---
 proxy/forwarder.go   | 10 +++++-----
 strategy/strategy.go | 19 +++++++++++++------
 2 files changed, 18 insertions(+), 11 deletions(-)

diff --git a/proxy/forwarder.go b/proxy/forwarder.go
index e974627..8a2e8bc 100644
--- a/proxy/forwarder.go
+++ b/proxy/forwarder.go
@@ -19,7 +19,7 @@ type Forwarder struct {
 	latency     int
 }
 
-// ForwarderFromURL returns a new forwarder
+// ForwarderFromURL parses `forward=` command line and returns a new forwarder
 func ForwarderFromURL(s string) (f *Forwarder, err error) {
 	ss := strings.Split(s, "#")
 	var d Dialer
@@ -38,7 +38,7 @@ func ForwarderFromURL(s string) (f *Forwarder, err error) {
 	return f, err
 }
 
-// NewForwarder .
+// NewForwarder returns a new forwarder
 func NewForwarder(dialer Dialer) *Forwarder {
 	return &Forwarder{Dialer: dialer, addr: dialer.Addr()}
 }
@@ -83,18 +83,18 @@ func (f *Forwarder) Failures() uint32 {
 	return atomic.LoadUint32(&f.failures)
 }
 
-// Enable .
+// Enable the forwarder
 func (f *Forwarder) Enable() {
 	atomic.StoreUint32(&f.disabled, 0)
 	atomic.StoreUint32(&f.failures, 0)
 }
 
-// Disable .
+// Disable the forwarder
 func (f *Forwarder) Disable() {
 	atomic.StoreUint32(&f.disabled, 1)
 }
 
-// Enabled .
+// Enabled returns the status of forwarder
 func (f *Forwarder) Enabled() bool {
 	return !isTrue(atomic.LoadUint32(&f.disabled))
 }
diff --git a/strategy/strategy.go b/strategy/strategy.go
index 509c267..8c65c03 100644
--- a/strategy/strategy.go
+++ b/strategy/strategy.go
@@ -77,7 +77,12 @@ type rrDialer struct {
 // newRRDialer returns a new rrDialer
 func newRRDialer(fs []*proxy.Forwarder, website string, interval int) *rrDialer {
 	rr := &rrDialer{fwdrs: fs}
+
 	rr.website = website
+	if strings.IndexByte(rr.website, ':') == -1 {
+		rr.website += ":80"
+	}
+
 	rr.interval = interval
 
 	sort.Sort(rr.fwdrs)
@@ -143,16 +148,18 @@ func (rr *rrDialer) checkDialer(idx int) {
 	retry := 1
 	buf := make([]byte, 4)
 
-	if strings.IndexByte(rr.website, ':') == -1 {
-		rr.website = rr.website + ":80"
-	}
-
 	d := rr.fwdrs[idx]
 
 	for {
-		time.Sleep(time.Duration(rr.interval) * time.Second * time.Duration(retry>>1))
-		retry <<= 1
 
+		time.Sleep(time.Duration(rr.interval) * time.Second * time.Duration(retry>>1))
+
+		// check forwarders whose priority not less than current priority only
+		if d.Priority < rr.priority {
+			continue
+		}
+
+		retry <<= 1
 		if retry > 16 {
 			retry = 16
 		}