Implement ticker caching

freqtrade/pairlist/pairlistmanager.py

@@ -4,6 +4,7 @@ Static List provider
 Provides lists as configured in config.json
 
  """
+from cachetools import TTLCache, cached
 import logging
 from typing import Dict, List
 
@@ -68,6 +69,10 @@ class PairListManager():
         """
         return [{p.name: p.short_desc()} for p in self._pairlists]
 
+    @cached(TTLCache(maxsize=1, ttl=1800))
+    def _get_cached_tickers(self):
+        return self._exchange.get_tickers()
+
     def refresh_pairlist(self) -> None:
         """
         Run pairlist through all configured pairlists.
@@ -78,7 +83,7 @@ class PairListManager():
         # tickers should be cached to avoid calling the exchange on each call.
         tickers: Dict = {}
         if self._tickers_needed:
-            tickers = self._exchange.get_tickers()
+            tickers = self._get_cached_tickers()
 
         # Process all pairlists in chain
         for pl in self._pairlists:

requirements-common.txt

@@ -4,6 +4,7 @@ ccxt==1.19.14
 SQLAlchemy==1.3.10
 python-telegram-bot==12.2.0
 arrow==0.15.4
+cachetools==3.1.1
 requests==2.22.0
 urllib3==1.25.6
 wrapt==1.11.2

setup.py

@@ -66,6 +66,7 @@ setup(name='freqtrade',
           'SQLAlchemy',
           'python-telegram-bot',
           'arrow',
+          'cachetools',
           'requests',
           'urllib3',
           'wrapt',

tests/pairlist/test_pairlist.py

@@ -268,12 +268,14 @@ def test_volumepairlist_caching(mocker, markets, whitelist_conf, tickers):
                           )
     bot = get_patched_freqtradebot(mocker, whitelist_conf)
     assert bot.pairlists._pairlists[0]._last_refresh == 0
-
+    assert tickers.call_count == 0
     bot.pairlists.refresh_pairlist()
+    assert tickers.call_count == 1
 
     assert bot.pairlists._pairlists[0]._last_refresh != 0
     lrf = bot.pairlists._pairlists[0]._last_refresh
     bot.pairlists.refresh_pairlist()
+    assert tickers.call_count == 1
     # Time should not be updated.
     assert bot.pairlists._pairlists[0]._last_refresh == lrf