From b6b9c8e5cc401bb5f876d74515b652cb5a5e6537 Mon Sep 17 00:00:00 2001
From: Matthias <xmatthias@outlook.com>
Date: Tue, 13 Oct 2020 07:11:08 +0200
Subject: [PATCH] Move "slow-log" to it's own mixin

---
 freqtrade/mixins/__init__.py      |  2 ++
 freqtrade/mixins/logging_mixin.py | 34 +++++++++++++++++++++++++++++++
 freqtrade/pairlist/IPairList.py   | 25 +++--------------------
 3 files changed, 39 insertions(+), 22 deletions(-)
 create mode 100644 freqtrade/mixins/__init__.py
 create mode 100644 freqtrade/mixins/logging_mixin.py

diff --git a/freqtrade/mixins/__init__.py b/freqtrade/mixins/__init__.py
new file mode 100644
index 000000000..f4a640fa3
--- /dev/null
+++ b/freqtrade/mixins/__init__.py
@@ -0,0 +1,2 @@
+# flake8: noqa: F401
+from freqtrade.mixins.logging_mixin import LoggingMixin
diff --git a/freqtrade/mixins/logging_mixin.py b/freqtrade/mixins/logging_mixin.py
new file mode 100644
index 000000000..4e19e45a4
--- /dev/null
+++ b/freqtrade/mixins/logging_mixin.py
@@ -0,0 +1,34 @@
+
+
+from cachetools import TTLCache, cached
+
+
+class LoggingMixin():
+    """
+    Logging Mixin
+    Shows similar messages only once every `refresh_period`.
+    """
+    def __init__(self, logger, refresh_period: int = 3600):
+        """
+        :param refresh_period: in seconds - Show identical messages in this intervals
+        """
+        self.logger = logger
+        self.refresh_period = refresh_period
+        self._log_cache: TTLCache = TTLCache(maxsize=1024, ttl=self.refresh_period)
+
+    def log_on_refresh(self, logmethod, message: str) -> None:
+        """
+        Logs message - not more often than "refresh_period" to avoid log spamming
+        Logs the log-message as debug as well to simplify debugging.
+        :param logmethod: Function that'll be called. Most likely `logger.info`.
+        :param message: String containing the message to be sent to the function.
+        :return: None.
+        """
+        @cached(cache=self._log_cache)
+        def _log_on_refresh(message: str):
+            logmethod(message)
+
+        # Log as debug first
+        self.logger.debug(message)
+        # Call hidden function.
+        _log_on_refresh(message)
diff --git a/freqtrade/pairlist/IPairList.py b/freqtrade/pairlist/IPairList.py
index c869e499b..5f29241ce 100644
--- a/freqtrade/pairlist/IPairList.py
+++ b/freqtrade/pairlist/IPairList.py
@@ -6,16 +6,15 @@ from abc import ABC, abstractmethod, abstractproperty
 from copy import deepcopy
 from typing import Any, Dict, List
 
-from cachetools import TTLCache, cached
-
 from freqtrade.exceptions import OperationalException
 from freqtrade.exchange import market_is_active
+from freqtrade.mixins import LoggingMixin
 
 
 logger = logging.getLogger(__name__)
 
 
-class IPairList(ABC):
+class IPairList(LoggingMixin, ABC):
 
     def __init__(self, exchange, pairlistmanager,
                  config: Dict[str, Any], pairlistconfig: Dict[str, Any],
@@ -36,7 +35,7 @@ class IPairList(ABC):
         self._pairlist_pos = pairlist_pos
         self.refresh_period = self._pairlistconfig.get('refresh_period', 1800)
         self._last_refresh = 0
-        self._log_cache: TTLCache = TTLCache(maxsize=1024, ttl=self.refresh_period)
+        LoggingMixin.__init__(self, logger, self.refresh_period)
 
     @property
     def name(self) -> str:
@@ -46,24 +45,6 @@ class IPairList(ABC):
         """
         return self.__class__.__name__
 
-    def log_on_refresh(self, logmethod, message: str) -> None:
-        """
-        Logs message - not more often than "refresh_period" to avoid log spamming
-        Logs the log-message as debug as well to simplify debugging.
-        :param logmethod: Function that'll be called. Most likely `logger.info`.
-        :param message: String containing the message to be sent to the function.
-        :return: None.
-        """
-
-        @cached(cache=self._log_cache)
-        def _log_on_refresh(message: str):
-            logmethod(message)
-
-        # Log as debug first
-        logger.debug(message)
-        # Call hidden function.
-        _log_on_refresh(message)
-
     @abstractproperty
     def needstickers(self) -> bool:
         """