Chore: make the code more semantic

adapters/outbound/util.go

@@ -0,0 +1,93 @@
+package adapters
+
+import (
+	"fmt"
+	"net"
+	"net/http"
+	"net/url"
+	"time"
+
+	C "github.com/Dreamacro/clash/constant"
+)
+
+// 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.Generator(&addr)
+	if err != nil {
+		return
+	}
+	defer instance.Close()
+	transport := &http.Transport{
+		Dial: func(string, string) (net.Conn, error) {
+			return instance.Conn(), nil
+		},
+		// from http.DefaultTransport
+		MaxIdleConns:          100,
+		IdleConnTimeout:       90 * time.Second,
+		TLSHandshakeTimeout:   10 * time.Second,
+		ExpectContinueTimeout: 1 * time.Second,
+	}
+	client := http.Client{Transport: transport}
+	req, err := client.Get(url)
+	if err != nil {
+		return
+	}
+	req.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 {
+		return
+	}
+
+	port := u.Port()
+	if port == "" {
+		if u.Scheme == "https" {
+			port = "443"
+		} else if u.Scheme == "http" {
+			port = "80"
+		} else {
+			err = fmt.Errorf("%s scheme not Support", rawURL)
+			return
+		}
+	}
+
+	addr = C.Metadata{
+		AddrType: C.AtypDomainName,
+		Host:     u.Hostname(),
+		IP:       nil,
+		Port:     port,
+	}
+	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)
+		tcp.SetKeepAlivePeriod(3 * time.Minute)
+	}
+}