users now see their position in the queue update

in real time

src/utils/observer.py

@@ -12,6 +12,10 @@ class Status(Enum):
 
 
 class Observer(ABC):
+    @abstractmethod
+    def updateStarted(self):
+        ...
+
     @abstractmethod
     def updatePercentage(self, percentage: float):
         ...
@@ -24,12 +28,15 @@ class Observer(ABC):
 class SocketObserver(Observer):
     socket2obs: dict[str, "SocketObserver"] = {}
 
-    def __init__(self, sid: str, socket_emit: Callable[[str, Any], None]) -> None:
+    def __init__(self, sid: str, socket_emit: Callable) -> None:
         super().__init__()
         self.sid = sid
         self.socket_emit = socket_emit
         SocketObserver.socket2obs[self.sid] = self
 
+    def updateStarted(self):
+        self.socket_emit("started-processing")
+
     def updatePercentage(self, percentage: float):
         self.socket_emit("progress", {'percent': percentage})
 
@@ -39,6 +46,8 @@ class SocketObserver(Observer):
 
 
 class Subject:
+    obs2subject: dict[Observer, "Subject"] = {}
+
     def __init__(self, id: str, type_: str, task: Callable) -> None:
         self.id = id
         self.type = type_
@@ -50,9 +59,16 @@ class Subject:
 
     def registerObserver(self, observer: Observer) -> None:
         self.observers.add(observer)
+        Subject.obs2subject[observer] = self
 
     def unregisterObserver(self, observer: Observer):
         self.observers.remove(observer)
+        Subject.obs2subject.pop(observer)
+
+    def notifyStarted(self):
+        self.status = Status.PROCESSING
+        for observer in self.observers:
+            observer.updateStarted
 
     def notifyPercentage(self, percentage: float):
         self.percent = percentage
@@ -63,8 +79,10 @@ class Subject:
         self.status = Status.COMPLETE
         for observer in self.observers:
             observer.updateComplete({"type": self.type, "results": results})
+            Subject.obs2subject.pop(observer)
+        self.observers.clear()
         self.results = results
         # TODO: maybe save results to disk here?
 
 
-request2status: dict[str, Subject] = {}
+uuid2subject: dict[str, Subject] = {}