From eeb36b64881a6bb9fb54582402e789d7e8444268 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Krist=C3=B3f=20T=C3=B3th?= <kristof.toth@avatao.com>
Date: Mon, 30 Jul 2018 17:55:52 +0200
Subject: [PATCH] Implement IOLoop based AsyncRateLimiter

---
 lib/tfw/decorators/rate_limiter.py | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/lib/tfw/decorators/rate_limiter.py b/lib/tfw/decorators/rate_limiter.py
index 2f21eac..6fb020a 100644
--- a/lib/tfw/decorators/rate_limiter.py
+++ b/lib/tfw/decorators/rate_limiter.py
@@ -31,3 +31,22 @@ class RateLimiter:
         if seconds_to_next_call > 0:
             return seconds_to_next_call
         return 0
+
+
+class AsyncRateLimiter(RateLimiter):
+    def __init__(self, rate_per_second, ioloop):
+        self.ioloop = ioloop
+        self.last_callback = None
+        super().__init__(
+            rate_per_second=rate_per_second,
+            action=self.async_action
+        )
+
+    def async_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
+        )