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//
// rhrdtime
//
// The Radio Helsinki Rivendell Time Websocket Server
//
//
// Copyright (C) 2015 Christian Pointner <equinox@helsinki.at>
//
// This file is part of rhrdtime.
//
// rhrdtime is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// any later version.
//
// rhrdtime is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with rhrdtime. If not, see <http://www.gnu.org/licenses/>.
//
package main
import (
"fmt"
"time"
"flag"
"net/http"
"encoding/json"
"github.com/codegangsta/martini"
"github.com/gorilla/websocket"
"github.com/tuxychandru/pubsub"
)
type timeUpdate struct {
Timestamp int64 `json:"timestamp"`
Week uint8 `json:"week"`
}
func getTimeUpdate() []byte {
now := time.Now()
update := timeUpdate{now.Unix(), 1}
update_json, err := json.Marshal(update)
if err != nil {
fmt.Println(err)
return []byte{'{', '}'}
}
return update_json
}
func goTalkWithClient(w http.ResponseWriter, r *http.Request, ps *pubsub.PubSub) {
ws, err := websocket.Upgrade(w, r, nil, 1024, 1024)
if _, ok := err.(websocket.HandshakeError); ok {
http.Error(w, "Not a websocket handshake", 400)
return
} else if err != nil {
fmt.Println(err)
return
}
fmt.Println("Client connected", ws.RemoteAddr())
timeupdate_chan := ps.Sub("timeupdate")
defer ps.Unsub(timeupdate_chan, "timeupdate")
update_json := getTimeUpdate()
if err := ws.WriteMessage(websocket.TextMessage, update_json); err != nil {
return
}
for jsonupdate := range timeupdate_chan {
if err := ws.WriteMessage(websocket.TextMessage, jsonupdate.([]byte)); err != nil {
return
}
}
}
func RunMartini(ps *pubsub.PubSub) {
m := martini.Classic()
m.Get("/time", func(w http.ResponseWriter, r *http.Request) {
goTalkWithClient(w, r, ps)
})
m.Run()
}
func main() {
interval_s := flag.String("interval", "15s", "the interval between updates, default: 15s")
help := flag.Bool("help", false, "show usage")
flag.Parse()
if *help {
flag.Usage()
return
}
interval, err := time.ParseDuration(*interval_s)
if err != nil {
fmt.Println(err)
return
}
ps := pubsub.New(1)
ticker := time.NewTicker(interval)
go func() {
for _ = range ticker.C {
ps.Pub(getTimeUpdate(), "timeupdate")
}
}()
RunMartini(ps)
}
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