Prevent queuing lots of setTypingState

@futurize() is now called with parentheses and can take a max_instances
int argument. This is used for setTypingState to not have more than one
queued calls per room and True/False state and avoids bombing the server
with old ephemeral events after a network loss and reconnection.

harmonyqml/backend/backend.py

@@ -48,7 +48,7 @@ class Backend(QObject):
 
     @pyqtSlot(str, result="QVariant")
     @pyqtSlot(str, bool, result="QVariant")
-    @futurize
+    @futurize()
     def getUserDisplayName(self, user_id: str, can_block: bool = True) -> str:
         if user_id in self._queried_displaynames:
             return self._queried_displaynames[user_id]

harmonyqml/backend/client.py

@@ -77,14 +77,14 @@ class Client(QObject):
 
     @pyqtSlot(str)
     @pyqtSlot(str, str)
-    @futurize
+    @futurize()
     def login(self, password: str, device_name: str = "") -> None:
         response = self.net.talk(self.nio.login, password, device_name)
         self.nio_sync.receive_response(response)
 
 
     @pyqtSlot(str, str, str)
-    @futurize
+    @futurize()
     def resumeSession(self, user_id: str, token: str, device_id: str
                      ) -> None:
         response = nr.LoginResponse(user_id, device_id, token)
@@ -93,7 +93,7 @@ class Client(QObject):
 
 
     @pyqtSlot()
-    @futurize
+    @futurize()
     def logout(self) -> None:
         self._stop_sync.set()
         self.net.http_disconnect()
@@ -101,7 +101,7 @@ class Client(QObject):
 
 
     @pyqtSlot()
-    @futurize
+    @futurize()
     def startSyncing(self) -> None:
         while True:
             self._on_sync(self.net_sync.talk(
@@ -141,7 +141,7 @@ class Client(QObject):
             self.roomLeft.emit(room_id)
 
 
-    @futurize
+    @futurize()
     def loadPastEvents(self, room_id: str, start_token: str, limit: int = 100
                       ) -> None:
         # From QML, use Backend.loastPastEvents instead
@@ -170,7 +170,7 @@ class Client(QObject):
 
 
     @pyqtSlot(str, bool)
-    @futurize
+    @futurize(max_instances=1)
     def setTypingState(self, room_id: str, typing: bool) -> None:
         set_for_secs        = 5
         last_set, last_time = self._last_typing_set[room_id]
@@ -183,6 +183,7 @@ class Client(QObject):
 
         self._last_typing_set[room_id] = (typing, time.time())
 
+        print("send", typing)
         self.net.talk(
             self.nio.room_typing,
             room_id        = room_id,
@@ -192,7 +193,7 @@ class Client(QObject):
 
 
     @pyqtSlot(str, str)
-    @futurize
+    @futurize()
     def sendMarkdown(self, room_id: str, text: str) -> None:
         html = self.manager.backend.htmlFilter.fromMarkdown(text)
         content = {

harmonyqml/backend/pyqt_future.py

@@ -5,9 +5,8 @@ import functools
 import logging
 import sys
 import traceback
-from concurrent.futures import Future
+from concurrent.futures import Executor, Future
-from threading import currentThread
+from typing import Callable, List, Optional, Tuple, Union
-from typing import Callable, Optional, Union
 
 from PyQt5.QtCore import QObject, pyqtProperty, pyqtSignal, pyqtSlot
 
@@ -63,17 +62,33 @@ class PyQtFuture(QObject):
         self.future.add_done_callback(fn)
 
 
-def futurize(func: Callable) -> Callable:
+_RUNNING: List[Tuple[Executor, Callable, tuple, dict]] = []
+
+
+def futurize(max_instances: Optional[int] = None) -> Callable:
+
+    def decorator(func: Callable) -> Callable:
+
         @functools.wraps(func)
-    def wrapper(self, *args, **kwargs) -> PyQtFuture:
+        def wrapper(self, *args, **kws) -> Optional[PyQtFuture]:
             def run_and_catch_errs():
                 # Without this, exceptions are silently ignored
                 try:
-                return func(self, *args, **kwargs)
+                    return func(self, *args, **kws)
                 except Exception:
                     traceback.print_exc()
-                logging.error("Exiting %s due to exception.", currentThread())
+                    logging.error("Exiting thread due to exception.")
                     sys.exit(1)
+                finally:
+                    del _RUNNING[_RUNNING.index((self.pool, func, args, kws))]
 
+            if max_instances is not None and \
+               _RUNNING.count((self.pool, func, args, kws)) >= max_instances:
+                return None
+
+            _RUNNING.append((self.pool, func, args, kws))
             return PyQtFuture(self.pool.submit(run_and_catch_errs), self)
+
         return wrapper
+
+    return decorator