116 lines
2.6 KiB
Go
116 lines
2.6 KiB
Go
package main
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import (
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"fmt"
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"log"
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"net/http"
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"os"
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"strconv"
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"time"
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"github.com/joho/godotenv"
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"github.com/julienschmidt/httprouter"
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"github.com/go-redis/redis"
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)
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var listen string
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var redisHost string
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type RawClient struct {
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UserId string
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ClientId string
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}
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var connections map[RawClient][]chan []byte
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var redisClient *redis.Client
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func main() {
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// Load .env
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err := godotenv.Load()
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if err != nil {
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log.Fatal("Error loading .env file")
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}
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listen = os.Getenv("LISTEN")
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redisHost = os.Getenv("REDIS")
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connections = make(map[RawClient][]chan []byte)
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// Redis
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redisClient = redis.NewClient(&redis.Options{
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Addr: redisHost,
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Password: "",
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DB: 0,
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})
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// Routes
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router := httprouter.New()
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router.GET("/subscribe/:userid/client/:clientid", Subscribe)
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router.POST("/ping/:userid/client/:clientid", PostTime)
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// Start server
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log.Printf("starting server on %s", listen)
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log.Fatal(http.ListenAndServe(listen, router))
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}
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func Subscribe(w http.ResponseWriter, r *http.Request, p httprouter.Params) {
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flusher, ok := w.(http.Flusher)
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if !ok {
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http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
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return
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}
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w.Header().Set("Content-Type", "text/event-stream")
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w.Header().Set("Cache-Control", "no-cache")
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w.Header().Set("Connection", "keep-alive")
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client := RawClient {
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UserId: p.ByName("userid"),
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ClientId: p.ByName("clintid"),
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}
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recv := make(chan []byte)
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connections[client] = append(connections[client], recv);
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// Refresh connection periodically
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resClosed := w.(http.CloseNotifier).CloseNotify()
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ticker := time.NewTicker(25 * time.Second)
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// Push cached value (if it exists) to the connection
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cachedTime, err := redisClient.Get(client.UserId + client.ClientId).Result()
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if err == nil {
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fmt.Fprintf(w, "data: %s\n\n", cachedTime)
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flusher.Flush()
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}
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for {
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select {
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case msg := <- recv:
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fmt.Fprintf(w, "data: %s\n\n", msg)
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flusher.Flush()
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case <- ticker.C:
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w.Write([]byte(":\n\n"))
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case <- resClosed:
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ticker.Stop()
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delete(connections, client)
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return
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}
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}
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}
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// TODO: Take client data from token
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func PostTime(w http.ResponseWriter, r *http.Request, p httprouter.Params) {
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client := RawClient {
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UserId: p.ByName("userid"),
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ClientId: p.ByName("clientid"),
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}
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time := []byte(strconv.FormatInt(time.Now().UTC().Unix(), 10)) // UTC Epoch Time in []byte
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key := client.UserId + client.ClientId
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_ = redisClient.Set(key, time, 0)
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for _, connection := range connections[client] {
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connection <- time
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}
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w.WriteHeader(http.StatusOK)
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}
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