Add monkeypatching hack on the event loop

Previously inside slixmpp, it’s cleaner to do it only in poezio.

2 files changed, 45 insertions, 0 deletions

diff --git a/poezio/asyncio.py b/poezio/asyncio.py
new file mode 100644
index 00000000..2b02a91f
--- /dev/null
+++ b/poezio/asyncio.py
@@ -0,0 +1,42 @@
+"""
+A module that monkey patches the standard asyncio module to add an
+idle_call() method to the main loop. This method is used to execute a
+callback whenever the loop is not busy handling anything else. This means
+that it is a callback with lower priority than IO, timer, or even
+call_soon() ones. These callback are called only once each.
+"""
+
+import asyncio
+import functools
+import collections
+from asyncio import events
+
+import slixmpp
+
+
+def monkey_patch_asyncio_slixmpp():
+    def idle_call(self, callback):
+        if asyncio.iscoroutinefunction(callback):
+            raise TypeError("coroutines cannot be used with idle_call()")
+        handle = events.Handle(callback, [], self)
+        self._idle.append(handle)
+
+    def my_run_once(self):
+        if self._idle:
+            self._ready.append(events.Handle(lambda: None, (), self))
+        real_run_once(self)
+        if self._idle:
+            handle = self._idle.popleft()
+            handle._run()
+    cls = asyncio.get_event_loop().__class__
+    cls._idle = collections.deque()
+    cls.idle_call = idle_call
+    real_run_once = cls._run_once
+    cls._run_once = my_run_once
+
+    spawn_event = slixmpp.xmlstream.XMLStream._spawn_event
+    def patchy(self, xml):
+        self.loop.idle_call(functools.partial(spawn_event, self, xml))
+    slixmpp.xmlstream.XMLStream._spawn_event = patchy
+
+
diff --git a/poezio/poezio.py b/poezio/poezio.py
index 55c1afea..784f0553 100644
--- a/poezio/poezio.py
+++ b/poezio/poezio.py
@@ -61,6 +61,9 @@ def main():
         config.check_config()
         sys.exit(0)
 
+    from poezio.asyncio import monkey_patch_asyncio_slixmpp
+    monkey_patch_asyncio_slixmpp()
+
     from poezio import theming
     theming.update_themes_dir()