/
main.go
111 lines (90 loc) · 2.33 KB
/
main.go
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package main
import (
"log"
"net/http"
"time"
"github.com/gorilla/websocket"
)
const (
// Time allowed to write the response 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
)
var upgrader = websocket.Upgrader{
ReadBufferSize: 1024,
WriteBufferSize: 1024,
}
func main() {
log.Println("Starting server on port 8080")
http.HandleFunc("/", serveWs)
if err := http.ListenAndServe(":8080", nil); err != nil {
log.Fatal(err)
}
}
func serveWs(w http.ResponseWriter, r *http.Request) {
log.Println("Connection made")
//Upgrade the http connection to a websocket
var upgrader = websocket.Upgrader{
CheckOrigin: func(r *http.Request) bool { return true },
}
ws, err := upgrader.Upgrade(w, r, nil)
if err != nil {
if _, ok := err.(websocket.HandshakeError); !ok {
log.Println(err)
}
return // If there's an error we want to bail
}
connection := Connection{websocket: *ws}
connection.init()
}
func wsReader(ws *websocket.Conn, mc chan string) {
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 {
_, msg, err := ws.ReadMessage()
if err != nil {
log.Println("Error when reading websocket message")
log.Println(err)
break
}
log.Println("Recieved message: " + string(msg))
mc <- string(msg)
}
}
func wsWriter(ws *websocket.Conn, mc chan string) {
pingTicker := time.NewTicker(pingPeriod)
defer func() {
pingTicker.Stop()
ws.Close()
}()
for {
select {
case msg := <- mc:
log.Println("Writing: " + msg)
if err := ws.WriteMessage(websocket.TextMessage, []byte(msg)); err != nil {
return
}
case <-pingTicker.C:
log.Println("Sending ping")
ws.SetWriteDeadline(time.Now().Add(writeWait))
if err := ws.WriteMessage(websocket.PingMessage, []byte{}); err != nil {
return
}
}
}
}
type Connection struct {
websocket websocket.Conn
}
func (c *Connection) init() {
log.Println("Initialising connection")
messageChannel := make(chan string)
//Create readers and writers
go wsWriter(&c.websocket, messageChannel)
go wsReader(&c.websocket, messageChannel)
}