.config/coc/extensions/coc-go-data/tools/pkg/mod/golang.org/x/tools@v0.0.0-20201028153306-37f0764111ff/cmd/getgo/server/main.go

   1 // Copyright 2017 The Go Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style
   3 // license that can be found in the LICENSE file.
   4
   5 // Command server serves get.golang.org, redirecting users to the appropriate
   6 // getgo installer based on the request path.
   7 package main
   8
   9 import (
  10         "fmt"
  11         "net/http"
  12         "os"
  13         "strings"
  14         "time"
  15 )
  16
  17 const (
  18         base             = "https://dl.google.com/go/getgo/"
  19         windowsInstaller = base + "installer.exe"
  20         linuxInstaller   = base + "installer_linux"
  21         macInstaller     = base + "installer_darwin"
  22 )
  23
  24 // substring-based redirects.
  25 var stringMatch = map[string]string{
  26         // via uname, from bash
  27         "MINGW":  windowsInstaller, // Reported as MINGW64_NT-10.0 in git bash
  28         "Linux":  linuxInstaller,
  29         "Darwin": macInstaller,
  30 }
  31
  32 func main() {
  33         http.HandleFunc("/", handler)
  34
  35         port := os.Getenv("PORT")
  36         if port == "" {
  37                 port = "8080"
  38                 fmt.Printf("Defaulting to port %s", port)
  39         }
  40
  41         fmt.Printf("Listening on port %s", port)
  42         if err := http.ListenAndServe(fmt.Sprintf(":%s", port), nil); err != nil {
  43                 fmt.Fprintf(os.Stderr, "http.ListenAndServe: %v", err)
  44         }
  45 }
  46
  47 func handler(w http.ResponseWriter, r *http.Request) {
  48         if containsIgnoreCase(r.URL.Path, "installer.exe") {
  49                 // cache bust
  50                 http.Redirect(w, r, windowsInstaller+cacheBust(), http.StatusFound)
  51                 return
  52         }
  53
  54         for match, redirect := range stringMatch {
  55                 if containsIgnoreCase(r.URL.Path, match) {
  56                         http.Redirect(w, r, redirect, http.StatusFound)
  57                         return
  58                 }
  59         }
  60
  61         http.NotFound(w, r)
  62 }
  63
  64 func containsIgnoreCase(s, substr string) bool {
  65         return strings.Contains(
  66                 strings.ToLower(s),
  67                 strings.ToLower(substr),
  68         )
  69 }
  70
  71 func cacheBust() string {
  72         return fmt.Sprintf("?%d", time.Now().Nanosecond())
  73 }