Improve: Dial would reset proxy alive status

adapters/outbound/util.go

@@ -4,7 +4,6 @@ import (
 	"crypto/tls"
 	"fmt"
 	"net"
-	"net/http"
 	"net/url"
 	"sync"
 	"time"
@@ -21,39 +20,6 @@ var (
 	once                     sync.Once
 )
 
-// DelayTest get the delay for the specified URL
-func DelayTest(proxy C.Proxy, url string) (t int16, err error) {
-	addr, err := urlToMetadata(url)
-	if err != nil {
-		return
-	}
-
-	start := time.Now()
-	instance, err := proxy.Dial(&addr)
-	if err != nil {
-		return
-	}
-	defer instance.Close()
-	transport := &http.Transport{
-		Dial: func(string, string) (net.Conn, error) {
-			return instance, nil
-		},
-		// from http.DefaultTransport
-		MaxIdleConns:          100,
-		IdleConnTimeout:       90 * time.Second,
-		TLSHandshakeTimeout:   10 * time.Second,
-		ExpectContinueTimeout: 1 * time.Second,
-	}
-	client := http.Client{Transport: transport}
-	resp, err := client.Get(url)
-	if err != nil {
-		return
-	}
-	resp.Body.Close()
-	t = int16(time.Since(start) / time.Millisecond)
-	return
-}
-
 func urlToMetadata(rawURL string) (addr C.Metadata, err error) {
 	u, err := url.Parse(rawURL)
 	if err != nil {
@@ -81,21 +47,6 @@ func urlToMetadata(rawURL string) (addr C.Metadata, err error) {
 	return
 }
 
-func selectFast(in chan interface{}) chan interface{} {
-	out := make(chan interface{})
-	go func() {
-		p, open := <-in
-		if open {
-			out <- p
-		}
-		close(out)
-		for range in {
-		}
-	}()
-
-	return out
-}
-
 func tcpKeepAlive(c net.Conn) {
 	if tcp, ok := c.(*net.TCPConn); ok {
 		tcp.SetKeepAlive(true)