Redmage/server/routes/events.go

58 lines
1.4 KiB
Go

package routes
import (
"encoding/json"
"io"
"net/http"
"github.com/tigorlazuardi/redmage/pkg/log"
)
func (routes *Routes) EventsAPI(rw http.ResponseWriter, r *http.Request) {
ctx, span := tracer.Start(r.Context(), "*Routes.EventsAPI")
defer span.End()
flush, ok := rw.(http.Flusher)
if !ok {
rw.WriteHeader(http.StatusInternalServerError)
_ = json.NewEncoder(rw).Encode(map[string]string{"error": "server does not support streaming"})
return
}
log.New(ctx).Info("new event stream connection", "user_agent", r.UserAgent())
rw.Header().Set("Content-Type", "text/event-stream")
rw.Header().Set("Cache-Control", "no-cache")
rw.Header().Set("Connection", "keep-alive")
rw.WriteHeader(200)
flush.Flush()
downloadEvent, closeDownloadEvent := routes.API.SubscribeImageDownloadEvent()
defer closeDownloadEvent()
enc := json.NewEncoder(rw)
for {
select {
case <-r.Context().Done():
log.New(ctx).Info("event stream connection closed", "user_agent", r.UserAgent())
return
case event := <-downloadEvent:
if _, err := io.WriteString(rw, "event: image_download\n"); err != nil {
return
}
if _, err := io.WriteString(rw, "data: "); err != nil {
return
}
if err := enc.Encode(event); err != nil {
return
}
// Single '\n' because enc.Encode already append '\n'
if _, err := io.WriteString(rw, "\n"); err != nil {
return
}
}
flush.Flush()
}
}