Convert https://github.com/phoboslab/jsmpeg websocket-relay.js to Go language

websocket-relay.go

package main

import (
	"log"
	"net/http"
	"sync"

	"github.com/gorilla/websocket"
)

var upgrader = websocket.Upgrader{
	CheckOrigin: func(r *http.Request) bool { return true },
	Subprotocols: []string{"null"},
}

func init() {
	lock := sync.RWMutex{}
	wsClients := make(map[*websocket.Conn]bool)
	http.HandleFunc("/ws/relay", func(w http.ResponseWriter, r *http.Request) {
		c, err := upgrader.Upgrade(w, r, nil)
		if err != nil {
			log.Println(err)
			return
		}
		log.Printf("New Websocket Connection: %v (%d) total", r.RemoteAddr, len(wsClients)+1)
		defer c.Close()

		wsClients[c] = true
		defer func() {
			lock.Lock()
			defer lock.Unlock()
			delete(wsClients, c)
		}()
		for {
			_, _, err := c.ReadMessage()
			if err != nil {
				break
			}
		}
	})

	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
		log.Printf("Stream connected: %v", r.RemoteAddr)
		buf := make([]byte, 4096)
		defer r.Body.Close()
		for {
			n, err := r.Body.Read(buf)
			if err != nil {
				break
			}
			log.Println("Reveive length:", len(buf[:n]))

			lock.RLock()
			for c, ok := range wsClients {
				if !ok {
					continue
				}
				if err := c.WriteMessage(websocket.BinaryMessage, buf[:n]); err != nil {
					wsClients[c] = false
				}
			}
			lock.RUnlock()
		}
	})
}

func main() {
	log.Fatal(http.ListenAndServe(":8100", nil))
}