Priority/backend.light/sse_stream.go

108 lines
2.2 KiB
Go

package main
import (
"crypto/sha256"
"fmt"
"io"
"log"
"net/http"
"slices"
"strconv"
"strings"
"github.com/gin-gonic/gin"
)
func InitSse() *SseStream {
sse := &SseStream{
Clients: make([]Client, 0),
MsgId: map[string]int{},
Events: events,
Data: initPriority(),
}
for i := range events {
sse.MsgId[events[i]] = 0
}
return sse
}
func (sse *SseStream) SseHeadersMiddleware() gin.HandlerFunc {
return func(c *gin.Context) {
c.Writer.Header().Set("Content-Type", "text/event-stream")
c.Writer.Header().Set("Cache-Control", "no-cache")
c.Writer.Header().Set("Connection", "keep-alive")
c.Writer.Header().Set("Transfer-Encoding", "chunked")
c.Next()
}
}
func (sse *SseStream) Stream(c *gin.Context) {
client := &Client{
Ip: c.Request.RemoteAddr,
Chan: make(ClientChan),
Events: c.QueryArray("event"),
}
log.Printf("events: %+v", client.Events)
client.Id = generateClientId(client.Ip, client.Events, 8)
sse.AddClient(*client)
defer func() {
sse.RemoveClient(client)
close(client.Chan)
log.Printf("Client %s disconnected", client.Ip)
}()
log.Printf("Client %s connected - TOT %+v", client.Ip, sse.Clients)
c.Stream(func(w io.Writer) bool {
msg, ok := <-client.Chan
if !ok {
return false
}
c.SSEvent(msg.Event, msg)
return true
})
}
func (sse *SseStream) AddClient(client Client) {
sse.Clients = append(sse.Clients, client)
}
func (sse *SseStream) RemoveClient(client *Client) {
for i, c := range sse.Clients {
if c.Id == client.Id {
sse.Clients = append(sse.Clients[:i], sse.Clients[i+1:]...)
return
}
}
}
func (sse *SseStream) Send(msg Message) {
sse.MsgId[msg.Event]++
msg.Id = strconv.Itoa(sse.MsgId[msg.Event])
for _, client := range sse.Clients {
if slices.Contains(client.Events, msg.Event) || slices.Contains(client.Events, "*") {
client.Chan <- msg
log.Printf("sent: %+v -> %+v", msg, client.Ip)
}
}
}
func (sse *SseStream) SendMsg(c *gin.Context) {
var msg Message
c.ShouldBind(&msg)
sse.Send(msg)
c.JSON(http.StatusOK, gin.H{"status": "msg"})
}
func generateClientId(ip string, events []string, len int) string {
str := ip + strings.Join(events, "|")
id := sha256.Sum256([]byte(str))
return fmt.Sprintf("%X", id)[0:len]
}