Move mixins and decorators to tfw module from tfw.components

lib/tfw/decorators/__init__.py

@@ -0,0 +1,4 @@
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+# All Rights Reserved. See LICENSE file for details.
+
+from .rate_limiter import RateLimiter

lib/tfw/decorators/rate_limiter.py

@@ -0,0 +1,25 @@
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+# All Rights Reserved. See LICENSE file for details.
+
+from functools import wraps
+from time import time, sleep
+
+
+class RateLimiter:
+    def __init__(self, rate_per_second):
+        self.min_interval = 1 / float(rate_per_second)
+        self.last_call = time()
+
+    def __call__(self, fun):
+        @wraps(fun)
+        def wrapper(*args, **kwargs):
+            self._limit_rate()
+            fun(*args, **kwargs)
+        return wrapper
+
+    def _limit_rate(self):
+        since_last_call = time() - self.last_call
+        to_next_call = self.min_interval - since_last_call
+        self.last_call = time()
+        if to_next_call > 0:
+            sleep(to_next_call)