mapserver/web/ws.go
2019-06-13 08:04:32 +02:00

104 lines
1.7 KiB
Go

package web
import (
"bytes"
"encoding/json"
"mapserver/app"
"math/rand"
"net/http"
"sync"
"github.com/gorilla/websocket"
"github.com/sirupsen/logrus"
)
type WS struct {
ctx *app.App
channels map[int]chan []byte
mutex *sync.RWMutex
clients int
}
func NewWS(ctx *app.App) *WS {
ws := WS{}
ws.mutex = &sync.RWMutex{}
ws.channels = make(map[int]chan []byte)
return &ws
}
var upgrader = websocket.Upgrader{
ReadBufferSize: 1024,
WriteBufferSize: 1024,
CheckOrigin: func(r *http.Request) bool {
return true
},
}
func (t *WS) OnEvent(eventtype string, o interface{}) {
data, err := json.Marshal(o)
if err != nil {
panic(err)
}
buf := new(bytes.Buffer)
buf.Write([]byte("{\"type\":\""))
buf.Write([]byte(eventtype))
buf.Write([]byte("\",\"data\":"))
buf.Write(data)
buf.Write([]byte("}"))
t.mutex.RLock()
defer t.mutex.RUnlock()
for _, c := range t.channels {
select {
case c <- buf.Bytes():
default:
}
}
}
func (t *WS) ServeHTTP(resp http.ResponseWriter, req *http.Request) {
conn, err := upgrader.Upgrade(resp, req, nil)
if err != nil {
fields := logrus.Fields{
"err": err,
}
logrus.WithFields(fields).Error("ws-upgrade")
}
id := rand.Intn(64000)
ch := make(chan []byte)
t.mutex.Lock()
t.channels[id] = ch
t.clients++
wsClients.Set(float64(t.clients))
t.mutex.Unlock()
for {
data := <-ch
if data == nil {
//how the hell got a nil reference in here..?!
//related issue: #18
continue
}
err := conn.WriteMessage(websocket.TextMessage, data)
if err != nil {
break
}
}
t.mutex.Lock()
t.clients--
wsClients.Set(float64(t.clients))
delete(t.channels, id)
close(ch)
t.mutex.Unlock()
}