From 3dff144b91e20ff1f6e9ccc2fd7694a894cabe41 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Krist=C3=B3f=20T=C3=B3th?= <kristof.toth@avatao.com>
Date: Tue, 31 Jul 2018 11:48:41 +0200
Subject: [PATCH] Fix RateLimiter family debounce stuff

---
 lib/tfw/decorators/rate_limiter.py | 44 ++++++++++++++----------------
 1 file changed, 21 insertions(+), 23 deletions(-)

diff --git a/lib/tfw/decorators/rate_limiter.py b/lib/tfw/decorators/rate_limiter.py
index 0f7f20b..abe6453 100644
--- a/lib/tfw/decorators/rate_limiter.py
+++ b/lib/tfw/decorators/rate_limiter.py
@@ -21,31 +21,28 @@ class RateLimiter:
     so it is only acceptable for stuff running on a separate thread.
 
     If this is no good for you please refer to AsyncRateLimiter in this module,
-    which is designed not to block and use the IOLoop it is being called from,
-    or redefine the action argument of __init__ (which defaults to time.sleep).
+    which is designed not to block and use the IOLoop it is being called from.
     """
-    def __init__(self, rate_per_second, action=sleep):
+    def __init__(self, rate_per_second):
         """
         :param rate_per_second: max frequency the decorated method should be
                                 invoked with
-        :param action: what to do when rate limiting. defaults to time.sleep,
-                       receives the number of seconds until the next invocation
-                       should occour as an argument
         """
         self.min_interval = 1 / float(rate_per_second)
-        self.action = action
         self.fun = None
         self.last_call = time()
 
+    def action(self, seconds_to_next_call):
+        if seconds_to_next_call:
+            sleep(seconds_to_next_call)
+        self.fun()
+
     def __call__(self, fun):
         @wraps(fun)
         def wrapper(*args, **kwargs):
             self.fun = partial(fun, *args, **kwargs)
             limit_seconds = self._limit_rate()
-            if limit_seconds:
-                self.action(limit_seconds)
-                return
-            self.fun()
+            self.action(limit_seconds)
         return wrapper
 
     def _limit_rate(self):
@@ -62,10 +59,11 @@ class AsyncRateLimiter(RateLimiter):
     """
     Decorator class for rate limiting, non-blocking.
 
-    The semantics of the rate limiting are similar to that of RateLimiter,
-    but this decorator never blocks, instead it adds an async callback version
-    of the decorated function to the IOLoop to be executed after the rate limiting
-    has expired.
+    The semantics of the rate limiting:
+        - unlike RateLimiter this decorator never blocks, instead it adds an async
+          callback version of the decorated function to the IOLoop
+          (to be executed after the rate limiting has expired).
+        - the timing works similarly to RateLimiter
     """
     def __init__(self, rate_per_second, ioloop_factory):
         """
@@ -79,24 +77,24 @@ class AsyncRateLimiter(RateLimiter):
         self._last_callback = None
 
         self._make_action_thread_safe()
-
-        super().__init__(
-            rate_per_second=rate_per_second,
-            action=self.async_action
-        )
+        super().__init__(rate_per_second=rate_per_second)
 
     def _make_action_thread_safe(self):
-        self.async_action = partial(self.ioloop.add_callback, self.async_action)
+        self.action = partial(self.ioloop.add_callback, self.action)
 
     @lazy_property
     def ioloop(self):
         return self._ioloop_factory()
 
-    def async_action(self, seconds_to_next_call):
+    def action(self, seconds_to_next_call):
         if self._last_callback:
             self.ioloop.remove_timeout(self._last_callback)
 
         self._last_callback = self.ioloop.call_later(
             seconds_to_next_call,
-            self.fun
+            self.fun_with_debounce
         )
+
+    def fun_with_debounce(self):
+        self.last_call = time()
+        self.fun()