source: code/trunk/vendor/github.com/valyala/fasthttp/fasthttpproxy/http.go@ 145

package fasthttpproxy

import (
        "bufio"
        "encoding/base64"
        "fmt"
        "net"
        "strings"
        "time"

        "github.com/valyala/fasthttp"
)

// FasthttpHTTPDialer returns a fasthttp.DialFunc that dials using
// the provided HTTP proxy.
//
// Example usage:
//      c := &fasthttp.Client{
//              Dial: fasthttpproxy.FasthttpHTTPDialer("username:password@localhost:9050"),
//      }
func FasthttpHTTPDialer(proxy string) fasthttp.DialFunc {
        return FasthttpHTTPDialerTimeout(proxy, 0)
}

// FasthttpHTTPDialerTimeout returns a fasthttp.DialFunc that dials using
// the provided HTTP proxy using the given timeout.
//
// Example usage:
//      c := &fasthttp.Client{
//              Dial: fasthttpproxy.FasthttpHTTPDialerTimeout("username:password@localhost:9050", time.Second * 2),
//      }
func FasthttpHTTPDialerTimeout(proxy string, timeout time.Duration) fasthttp.DialFunc {
        var auth string
        if strings.Contains(proxy, "@") {
                split := strings.Split(proxy, "@")
                auth = base64.StdEncoding.EncodeToString([]byte(split[0]))
                proxy = split[1]
        }

        return func(addr string) (net.Conn, error) {
                var conn net.Conn
                var err error
                if timeout == 0 {
                        conn, err = fasthttp.Dial(proxy)
                } else {
                        conn, err = fasthttp.DialTimeout(proxy, timeout)
                }
                if err != nil {
                        return nil, err
                }

                req := fmt.Sprintf("CONNECT %s HTTP/1.1\r\nHost: %s\r\n", addr, addr)
                if auth != "" {
                        req += "Proxy-Authorization: Basic " + auth + "\r\n"
                }
                req += "\r\n"

                if _, err := conn.Write([]byte(req)); err != nil {
                        return nil, err
                }

                res := fasthttp.AcquireResponse()
                defer fasthttp.ReleaseResponse(res)

                res.SkipBody = true

                if err := res.Read(bufio.NewReader(conn)); err != nil {
                        conn.Close()
                        return nil, err
                }
                if res.Header.StatusCode() != 200 {
                        conn.Close()
                        return nil, fmt.Errorf("could not connect to proxy: %s status code: %d", proxy, res.Header.StatusCode())
                }
                return conn, nil
        }
}