69 lines
1.7 KiB
Go
69 lines
1.7 KiB
Go
package routes
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import (
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"errors"
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"io"
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"net/http"
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"sync"
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"github.com/tigorlazuardi/redmage/pkg/log"
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)
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func (routes *Routes) CreateHotReloadRoute() http.HandlerFunc {
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var mu sync.Mutex
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knownClients := make(map[string]chan struct{})
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firstTime := make(chan struct{}, 1)
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firstTime <- struct{}{}
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return func(w http.ResponseWriter, r *http.Request) {
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id := r.URL.Query().Get("id")
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var ch chan struct{}
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if oldChannel, known := knownClients[id]; known {
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ch = oldChannel
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} else {
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ch = make(chan struct{}, 1)
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ch <- struct{}{}
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knownClients[id] = ch
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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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w.WriteHeader(200)
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for {
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select {
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case <-r.Context().Done():
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return
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case <-firstTime:
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// dispose own's channel buffer to prevent deadlock.
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// because it will be filled with new signal below.
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if len(ch) > 0 {
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<-ch
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}
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// broadcast to all connected clients
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// that hot reload is triggered.
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//
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// The sender only send one signal,
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// and the receiver is only one, and chosen at random, so
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// we have to propagate the signal to all
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// connected clients.
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mu.Lock()
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for _, ch := range knownClients {
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ch <- struct{}{}
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}
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mu.Unlock()
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case <-ch:
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_, err := io.WriteString(w, "data: Hot reload triggered\n\n")
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if err != nil {
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log.New(r.Context()).Err(err).Error("failed to send hot reload trigger", "channel_id", id)
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return
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}
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if w, ok := w.(http.Flusher); ok {
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w.Flush()
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} else {
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panic(errors.New("HotReload: ResponseWriter does not implement http.Flusher interface"))
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}
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}
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}
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}
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}
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