| 1 | package daemon |
| 2 | |
| 3 | import ( |
| 4 | "encoding/json" |
| 5 | "net/http" |
| 6 | "net/url" |
| 7 | "regexp" |
| 8 | "strings" |
| 9 | "time" |
| 10 | |
| 11 | "github.com/FelineStateMachine/tinyrelay/internal/event" |
| 12 | ) |
| 13 | |
| 14 | const ( |
| 15 | roomStreamKeepAlive = 25 * time.Second |
| 16 | roomStreamBuffer = 64 |
| 17 | ) |
| 18 | |
| 19 | var roomStreamPath = regexp.MustCompile(`^/rooms/([a-z0-9_-]{1,64})/stream$` ) |
| 20 | |
| 21 | func isRoomStreamPath(path string) bool { return roomStreamPath.MatchString(path) } |
| 22 | |
| 23 | // roomStreamHTTP serves GET /rooms/<id>/stream as server-sent events. Each |
| 24 | // event the viewer may see in the room arrives as "event: message" with the |
| 25 | // JSON event as data; a comment keeps the connection alive. The viewer is |
| 26 | // identified by the browser session cookie or a NIP-98 signature. |
| 27 | func (t *Tenant) roomStreamHTTP(w http.ResponseWriter, r *http.Request) { |
| 28 | ctx, finish := t.app.telemetry.Start(r.Context(), "rooms" ) |
| 29 | outcome := "error" |
| 30 | defer func() { finish(outcome) }() |
| 31 | if r.Method != http.MethodGet { |
| 32 | w.Header().Set("Allow" , "GET" ) |
| 33 | http.Error(w, "method not allowed" , http.StatusMethodNotAllowed) |
| 34 | outcome = "invalid" |
| 35 | return |
| 36 | } |
| 37 | id := roomStreamPath.FindStringSubmatch(r.URL.Path)[1] |
| 38 | if origin := r.Header.Get("Origin" ); origin != "" && r.Header.Get("Authorization" ) == "" { |
| 39 | base, err := url.Parse(t.requestURL(r)) |
| 40 | if err != nil || origin != base.Scheme+"://" +base.Host { |
| 41 | http.Error(w, "auth-required: sign this request" , http.StatusUnauthorized) |
| 42 | outcome = "unauthorized" |
| 43 | return |
| 44 | } |
| 45 | } |
| 46 | actor, err := t.resolveUIActor(r) |
| 47 | if err != nil { |
| 48 | browseHTTPError(w, err) |
| 49 | outcome = "unauthorized" |
| 50 | return |
| 51 | } |
| 52 | // Hold an operation only while checking access. A stream may stay open |
| 53 | // for hours and must not keep maintenance waiting; it ends instead when |
| 54 | // maintenance or shutdown begins. |
| 55 | opCtx, done, err := t.beginOperation(ctx) |
| 56 | if err != nil { |
| 57 | http.Error(w, err.Error(), http.StatusServiceUnavailable) |
| 58 | outcome = "busy" |
| 59 | return |
| 60 | } |
| 61 | err = t.browseRead(opCtx, actor) |
| 62 | if err == nil { |
| 63 | _, _, err = t.roomFor(opCtx, actor, id) |
| 64 | } |
| 65 | done() |
| 66 | if err != nil { |
| 67 | browseHTTPError(w, err) |
| 68 | outcome = "unauthorized" |
| 69 | return |
| 70 | } |
| 71 | flusher, ok := w.(http.Flusher) |
| 72 | if !ok { |
| 73 | http.Error(w, "streaming unsupported" , http.StatusInternalServerError) |
| 74 | return |
| 75 | } |
| 76 | session := browseSession(t, actor) |
| 77 | events := make(chan event.Event, roomStreamBuffer) |
| 78 | overflow := make(chan struct{}, 1) |
| 79 | stop := t.router.Listen(func(e event.Event) { |
| 80 | globalPresence := e.Kind == 20001 && event.Tag(e, "h" ) == "" && actor != "" |
| 81 | if globalPresence { |
| 82 | allowed, _, err := t.community.RoomWriteAllowed(r.Context(), id, e.PubKey) |
| 83 | if err != nil || !allowed { |
| 84 | return |
| 85 | } |
| 86 | } |
| 87 | if e.Kind == event.KIND_MARMOT_GROUP || (event.Tag(e, "h" ) != id && !globalPresence) { |
| 88 | return |
| 89 | } |
| 90 | select { |
| 91 | case events <- e: |
| 92 | default: |
| 93 | select { |
| 94 | case overflow <- struct{}{}: |
| 95 | default: |
| 96 | } |
| 97 | } |
| 98 | }) |
| 99 | defer stop() |
| 100 | w.Header().Set("Content-Type" , "text/event-stream; charset=utf-8" ) |
| 101 | w.Header().Set("Cache-Control" , "no-store, private" ) |
| 102 | w.Header().Set("X-Accel-Buffering" , "no" ) |
| 103 | w.WriteHeader(http.StatusOK) |
| 104 | if _, err := w.Write([]byte(": room " + id + "\n\n" )); err != nil { |
| 105 | return |
| 106 | } |
| 107 | flusher.Flush() |
| 108 | keepAlive := time.NewTicker(roomStreamKeepAlive) |
| 109 | defer keepAlive.Stop() |
| 110 | delivered := 0 |
| 111 | defer func() { |
| 112 | t.app.telemetry.Logger().Debug("room stream closed" , "events" , delivered, "outcome" , outcome) |
| 113 | }() |
| 114 | paused := t.maintenance.watch() |
| 115 | for { |
| 116 | select { |
| 117 | case <-r.Context().Done(): |
| 118 | outcome = "closed" |
| 119 | return |
| 120 | case <-t.workCtx.Done(): |
| 121 | outcome = "closed" |
| 122 | return |
| 123 | case <-paused: |
| 124 | if t.maintenance.blocked() { |
| 125 | outcome = "closed" |
| 126 | return |
| 127 | } |
| 128 | paused = t.maintenance.watch() |
| 129 | case <-overflow: |
| 130 | outcome = "busy" |
| 131 | return |
| 132 | case <-keepAlive.C: |
| 133 | if _, err := w.Write([]byte(": keep-alive\n\n" )); err != nil { |
| 134 | outcome = "closed" |
| 135 | return |
| 136 | } |
| 137 | flusher.Flush() |
| 138 | case e := <-events: |
| 139 | if !t.gate.CanSee(r.Context(), e, session, nil) { |
| 140 | continue |
| 141 | } |
| 142 | raw, err := json.Marshal(e) |
| 143 | if err != nil { |
| 144 | continue |
| 145 | } |
| 146 | var frame strings.Builder |
| 147 | frame.WriteString("event: message\ndata: " ) |
| 148 | frame.Write(raw) |
| 149 | frame.WriteString("\n\n" ) |
| 150 | if _, err := w.Write([]byte(frame.String())); err != nil { |
| 151 | outcome = "closed" |
| 152 | return |
| 153 | } |
| 154 | flusher.Flush() |
| 155 | delivered++ |
| 156 | } |
| 157 | } |
| 158 | } |