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-rw-r--r--Godeps/_workspace/src/github.com/gorilla/websocket/examples/filewatch/main.go193
1 files changed, 193 insertions, 0 deletions
diff --git a/Godeps/_workspace/src/github.com/gorilla/websocket/examples/filewatch/main.go b/Godeps/_workspace/src/github.com/gorilla/websocket/examples/filewatch/main.go
new file mode 100644
index 000000000..a2c7b85fa
--- /dev/null
+++ b/Godeps/_workspace/src/github.com/gorilla/websocket/examples/filewatch/main.go
@@ -0,0 +1,193 @@
+// Copyright 2013 The Gorilla WebSocket 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 (
+ "flag"
+ "io/ioutil"
+ "log"
+ "net/http"
+ "os"
+ "strconv"
+ "text/template"
+ "time"
+
+ "github.com/gorilla/websocket"
+)
+
+const (
+ // Time allowed to write the file to the client.
+ writeWait = 10 * time.Second
+
+ // Time allowed to read the next pong message from the client.
+ pongWait = 60 * time.Second
+
+ // Send pings to client with this period. Must be less than pongWait.
+ pingPeriod = (pongWait * 9) / 10
+
+ // Poll file for changes with this period.
+ filePeriod = 10 * time.Second
+)
+
+var (
+ addr = flag.String("addr", ":8080", "http service address")
+ homeTempl = template.Must(template.New("").Parse(homeHTML))
+ filename string
+ upgrader = websocket.Upgrader{
+ ReadBufferSize: 1024,
+ WriteBufferSize: 1024,
+ }
+)
+
+func readFileIfModified(lastMod time.Time) ([]byte, time.Time, error) {
+ fi, err := os.Stat(filename)
+ if err != nil {
+ return nil, lastMod, err
+ }
+ if !fi.ModTime().After(lastMod) {
+ return nil, lastMod, nil
+ }
+ p, err := ioutil.ReadFile(filename)
+ if err != nil {
+ return nil, fi.ModTime(), err
+ }
+ return p, fi.ModTime(), nil
+}
+
+func reader(ws *websocket.Conn) {
+ defer ws.Close()
+ ws.SetReadLimit(512)
+ ws.SetReadDeadline(time.Now().Add(pongWait))
+ ws.SetPongHandler(func(string) error { ws.SetReadDeadline(time.Now().Add(pongWait)); return nil })
+ for {
+ _, _, err := ws.ReadMessage()
+ if err != nil {
+ break
+ }
+ }
+}
+
+func writer(ws *websocket.Conn, lastMod time.Time) {
+ lastError := ""
+ pingTicker := time.NewTicker(pingPeriod)
+ fileTicker := time.NewTicker(filePeriod)
+ defer func() {
+ pingTicker.Stop()
+ fileTicker.Stop()
+ ws.Close()
+ }()
+ for {
+ select {
+ case <-fileTicker.C:
+ var p []byte
+ var err error
+
+ p, lastMod, err = readFileIfModified(lastMod)
+
+ if err != nil {
+ if s := err.Error(); s != lastError {
+ lastError = s
+ p = []byte(lastError)
+ }
+ } else {
+ lastError = ""
+ }
+
+ if p != nil {
+ ws.SetWriteDeadline(time.Now().Add(writeWait))
+ if err := ws.WriteMessage(websocket.TextMessage, p); err != nil {
+ return
+ }
+ }
+ case <-pingTicker.C:
+ ws.SetWriteDeadline(time.Now().Add(writeWait))
+ if err := ws.WriteMessage(websocket.PingMessage, []byte{}); err != nil {
+ return
+ }
+ }
+ }
+}
+
+func serveWs(w http.ResponseWriter, r *http.Request) {
+ ws, err := upgrader.Upgrade(w, r, nil)
+ if err != nil {
+ if _, ok := err.(websocket.HandshakeError); !ok {
+ log.Println(err)
+ }
+ return
+ }
+
+ var lastMod time.Time
+ if n, err := strconv.ParseInt(r.FormValue("lastMod"), 16, 64); err != nil {
+ lastMod = time.Unix(0, n)
+ }
+
+ go writer(ws, lastMod)
+ reader(ws)
+}
+
+func serveHome(w http.ResponseWriter, r *http.Request) {
+ if r.URL.Path != "/" {
+ http.Error(w, "Not found", 404)
+ return
+ }
+ if r.Method != "GET" {
+ http.Error(w, "Method not allowed", 405)
+ return
+ }
+ w.Header().Set("Content-Type", "text/html; charset=utf-8")
+ p, lastMod, err := readFileIfModified(time.Time{})
+ if err != nil {
+ p = []byte(err.Error())
+ lastMod = time.Unix(0, 0)
+ }
+ var v = struct {
+ Host string
+ Data string
+ LastMod string
+ }{
+ r.Host,
+ string(p),
+ strconv.FormatInt(lastMod.UnixNano(), 16),
+ }
+ homeTempl.Execute(w, &v)
+}
+
+func main() {
+ flag.Parse()
+ if flag.NArg() != 1 {
+ log.Fatal("filename not specified")
+ }
+ filename = flag.Args()[0]
+ http.HandleFunc("/", serveHome)
+ http.HandleFunc("/ws", serveWs)
+ if err := http.ListenAndServe(*addr, nil); err != nil {
+ log.Fatal(err)
+ }
+}
+
+const homeHTML = `<!DOCTYPE html>
+<html lang="en">
+ <head>
+ <title>WebSocket Example</title>
+ </head>
+ <body>
+ <pre id="fileData">{{.Data}}</pre>
+ <script type="text/javascript">
+ (function() {
+ var data = document.getElementById("fileData");
+ var conn = new WebSocket("ws://{{.Host}}/ws?lastMod={{.LastMod}}");
+ conn.onclose = function(evt) {
+ data.textContent = 'Connection closed';
+ }
+ conn.onmessage = function(evt) {
+ console.log('file updated');
+ data.textContent = evt.data;
+ }
+ })();
+ </script>
+ </body>
+</html>
+`