| // Copyright 2015 The Vanadium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| package main |
| |
| import ( |
| "bytes" |
| "encoding/base64" |
| "encoding/json" |
| "fmt" |
| "io/ioutil" |
| "net/http" |
| "path/filepath" |
| "strings" |
| "text/template" |
| |
| "v.io/jiri" |
| "v.io/x/lib/cmdline" |
| ) |
| |
| var ( |
| portFlag int |
| ) |
| |
| const ( |
| defaultRefreshMs = "5000" |
| ) |
| |
| var tmpl = template.Must(template.New("screenshot").Parse(` |
| <!DOCTYPE html> |
| <html> |
| <head> |
| <style> |
| body { |
| margin: 0px !important; |
| overflow: hidden; |
| } |
| img { |
| width: 100%; |
| height: 100%; |
| } |
| </style> |
| <script> |
| function loadScreenshot() { |
| var xhr = new XMLHttpRequest(); |
| xhr.onreadystatechange=function() { |
| if (xhr.readyState == 4 && xhr.status == 200) { |
| var data = JSON.parse(xhr.responseText); |
| var ele = document.getElementById('screenshot'); |
| if (ele) { |
| ele.src = 'data:image/png;base64,' + data.Data; |
| } |
| } |
| } |
| xhr.open("GET", "/data?n={{ .ScreenshotName }}", true); |
| xhr.send(); |
| } |
| |
| function pageLoaded() { |
| loadScreenshot(); |
| setInterval(loadScreenshot, {{ .RefreshMs }}); |
| } |
| </script> |
| </head> |
| <body onload="pageLoaded()"> |
| <img id="screenshot"></img> |
| </body> |
| </html> |
| `)) |
| |
| func init() { |
| cmdServe.Flags.IntVar(&portFlag, "port", 8000, "Port for the server.") |
| } |
| |
| // cmdServe represents the 'serve' command of the vkiosk tool. |
| var cmdServe = &cmdline.Command{ |
| Name: "serve", |
| Short: "Serve screenshots from local file system or Google Storage", |
| Long: "Serve screenshots from local file system or Google Storage.", |
| Runner: cmdline.RunnerFunc(runServe), |
| } |
| |
| func runServe(env *cmdline.Env, _ []string) (e error) { |
| jirix, err := jiri.NewX(env) |
| if err != nil { |
| return err |
| } |
| // Start server. |
| http.HandleFunc("/data", func(w http.ResponseWriter, r *http.Request) { |
| dataHandler(jirix, w, r) |
| }) |
| http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) { |
| indexHandler(jirix, w, r) |
| }) |
| if err := http.ListenAndServe(fmt.Sprintf(":%d", portFlag), nil); err != nil { |
| return fmt.Errorf("ListenAndServe(%d) failed: %v", portFlag, err) |
| } |
| |
| return nil |
| } |
| |
| // indexHandler handles requests for index.html. |
| func indexHandler(jirix *jiri.X, w http.ResponseWriter, r *http.Request) { |
| r.ParseForm() |
| // Parameter "n" specifies the name of the screenshot file. |
| name := r.Form.Get("n") |
| if name == "" { |
| respondWithError(jirix, fmt.Errorf("parameter 'n' not found"), w) |
| return |
| } |
| // Parameter "r" specifies the refresh interval. |
| refreshMs := r.Form.Get("r") |
| if refreshMs == "" { |
| refreshMs = defaultRefreshMs |
| } |
| data := struct { |
| ScreenshotName string |
| RefreshMs string |
| }{ |
| ScreenshotName: name, |
| RefreshMs: refreshMs, |
| } |
| if err := tmpl.Execute(w, data); err != nil { |
| respondWithError(jirix, fmt.Errorf("Execute() failed: %v", err), w) |
| return |
| } |
| } |
| |
| // dataHandler handles requests for /data. |
| // It reads screenshots from local file system or Google Storage, and returns |
| // base64 encoded string as JSON. |
| func dataHandler(jirix *jiri.X, w http.ResponseWriter, r *http.Request) { |
| r.ParseForm() |
| name := r.Form.Get("n") |
| if name == "" { |
| respondWithError(jirix, fmt.Errorf("parameter 'n' not found"), w) |
| return |
| } |
| bytes, err := readScreenshot(jirix, name) |
| if err != nil { |
| respondWithError(jirix, fmt.Errorf("%v", err), w) |
| return |
| } |
| encoded := base64.StdEncoding.EncodeToString(bytes) |
| jsonData := struct{ Data string }{ |
| Data: encoded, |
| } |
| bytes, err = json.Marshal(&jsonData) |
| if err != nil { |
| respondWithError(jirix, fmt.Errorf("Marshal() failed: %v", err), w) |
| return |
| } |
| w.Header().Set("Content-Type", "application/json") |
| w.Write(bytes) |
| } |
| |
| func readScreenshot(jirix *jiri.X, name string) ([]byte, error) { |
| if strings.HasPrefix(exportDirFlag, "gs://") { |
| args := []string{ |
| "-q", |
| "cat", |
| exportDirFlag + "/" + name, |
| } |
| var output bytes.Buffer |
| if err := jirix.NewSeq().Capture(&output, &output).Last("gsutil", args...); err != nil { |
| return nil, err |
| } |
| return output.Bytes(), nil |
| } |
| return ioutil.ReadFile(filepath.Join(exportDirFlag, name)) |
| } |
| |
| func respondWithError(jirix *jiri.X, err error, w http.ResponseWriter) { |
| fmt.Fprintf(jirix.Stderr(), "%v\n", err) |
| http.Error(w, "500 internal server error", http.StatusInternalServerError) |
| } |
