From e6900036215587ba4f00bc1dfffcf859553d131d Mon Sep 17 00:00:00 2001
From: xmatthias <xmatthias@outlook.com>
Date: Wed, 6 Jun 2018 20:18:16 +0200
Subject: [PATCH 1/4] reinstate caching for get_ticker

---
 freqtrade/exchange/__init__.py | 31 ++++++++++++++++++++++---------
 1 file changed, 22 insertions(+), 9 deletions(-)

diff --git a/freqtrade/exchange/__init__.py b/freqtrade/exchange/__init__.py
index 3c67db71f..89347b0dc 100644
--- a/freqtrade/exchange/__init__.py
+++ b/freqtrade/exchange/__init__.py
@@ -18,6 +18,8 @@ _API: ccxt.Exchange = None
 _CONF: Dict = {}
 API_RETRY_COUNT = 4
 
+_CACHED_TICKER: Dict[str, Any] = {}
+
 # Holds all open sell orders for dry_run
 _DRY_RUN_OPEN_ORDERS: Dict[str, Any] = {}
 
@@ -264,17 +266,28 @@ def get_tickers() -> Dict:
         raise OperationalException(e)
 
 
-# TODO: remove refresh argument, keeping it to keep track of where it was intended to be used
 @retrier
 def get_ticker(pair: str, refresh: Optional[bool] = True) -> dict:
-    try:
-        return _API.fetch_ticker(pair)
-    except (ccxt.NetworkError, ccxt.ExchangeError) as e:
-        raise TemporaryError(
-            'Could not load ticker history due to {}. Message: {}'.format(
-                e.__class__.__name__, e))
-    except ccxt.BaseError as e:
-        raise OperationalException(e)
+    global _CACHED_TICKER
+    if refresh or pair not in _CACHED_TICKER.keys():
+        try:
+            data = _API.fetch_ticker(pair)
+            try:
+                _CACHED_TICKER[pair] = {
+                    'bid': float(data['bid']),
+                }
+            except KeyError as e:
+                logger.debug("Could not cache ticker data for %s", pair)
+            return data
+        except (ccxt.NetworkError, ccxt.ExchangeError) as e:
+            raise TemporaryError(
+                'Could not load ticker history due to {}. Message: {}'.format(
+                    e.__class__.__name__, e))
+        except ccxt.BaseError as e:
+            raise OperationalException(e)
+    else:
+        logger.info("returning cached data for %s", pair)
+        return _CACHED_TICKER[pair]
 
 
 @retrier

From a901f21bcd3f70dc014f0d33d2c9d43a74bfa45a Mon Sep 17 00:00:00 2001
From: xmatthias <xmatthias@outlook.com>
Date: Wed, 6 Jun 2018 20:24:47 +0200
Subject: [PATCH 2/4] test ticker caching

---
 freqtrade/exchange/__init__.py            |  1 +
 freqtrade/tests/exchange/test_exchange.py | 10 ++++++++++
 2 files changed, 11 insertions(+)

diff --git a/freqtrade/exchange/__init__.py b/freqtrade/exchange/__init__.py
index 89347b0dc..98cb8db0b 100644
--- a/freqtrade/exchange/__init__.py
+++ b/freqtrade/exchange/__init__.py
@@ -275,6 +275,7 @@ def get_ticker(pair: str, refresh: Optional[bool] = True) -> dict:
             try:
                 _CACHED_TICKER[pair] = {
                     'bid': float(data['bid']),
+                    'ask': float(data['ask']),
                 }
             except KeyError as e:
                 logger.debug("Could not cache ticker data for %s", pair)
diff --git a/freqtrade/tests/exchange/test_exchange.py b/freqtrade/tests/exchange/test_exchange.py
index 56812c75e..ff4233eaf 100644
--- a/freqtrade/tests/exchange/test_exchange.py
+++ b/freqtrade/tests/exchange/test_exchange.py
@@ -310,9 +310,19 @@ def test_get_ticker(default_conf, mocker):
     # if not fetching a new result we should get the cached ticker
     ticker = get_ticker(pair='ETH/BTC')
 
+    assert api_mock.fetch_ticker.call_count == 1
     assert ticker['bid'] == 0.5
     assert ticker['ask'] == 1
 
+    assert 'ETH/BTC' in exchange._CACHED_TICKER
+    assert exchange._CACHED_TICKER['ETH/BTC']['bid'] == 0.5
+    assert exchange._CACHED_TICKER['ETH/BTC']['ask'] == 1
+
+    # Test caching
+    api_mock.fetch_ticker = MagicMock()
+    get_ticker(pair='ETH/BTC', refresh=False)
+    assert api_mock.fetch_ticker.call_count == 0
+
     with pytest.raises(TemporaryError):  # test retrier
         api_mock.fetch_ticker = MagicMock(side_effect=ccxt.NetworkError)
         mocker.patch('freqtrade.exchange._API', api_mock)

From 4a17671f45fb00a1be52dca832b4f031c95369f2 Mon Sep 17 00:00:00 2001
From: xmatthias <xmatthias@outlook.com>
Date: Wed, 6 Jun 2018 20:30:42 +0200
Subject: [PATCH 3/4] improve log message

---
 freqtrade/exchange/__init__.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/freqtrade/exchange/__init__.py b/freqtrade/exchange/__init__.py
index 98cb8db0b..5e768518b 100644
--- a/freqtrade/exchange/__init__.py
+++ b/freqtrade/exchange/__init__.py
@@ -287,7 +287,7 @@ def get_ticker(pair: str, refresh: Optional[bool] = True) -> dict:
         except ccxt.BaseError as e:
             raise OperationalException(e)
     else:
-        logger.info("returning cached data for %s", pair)
+        logger.info("returning cached ticker-data for %s", pair)
         return _CACHED_TICKER[pair]
 
 

From 771449053042ae43a6f950f3b2c53e4441193746 Mon Sep 17 00:00:00 2001
From: xmatthias <xmatthias@outlook.com>
Date: Wed, 6 Jun 2018 21:24:57 +0200
Subject: [PATCH 4/4] Test keyerror exception

---
 freqtrade/tests/exchange/test_exchange.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/freqtrade/tests/exchange/test_exchange.py b/freqtrade/tests/exchange/test_exchange.py
index ff4233eaf..97a723929 100644
--- a/freqtrade/tests/exchange/test_exchange.py
+++ b/freqtrade/tests/exchange/test_exchange.py
@@ -333,6 +333,10 @@ def test_get_ticker(default_conf, mocker):
         mocker.patch('freqtrade.exchange._API', api_mock)
         get_ticker(pair='ETH/BTC', refresh=True)
 
+    api_mock.fetch_ticker = MagicMock(return_value={})
+    mocker.patch('freqtrade.exchange._API', api_mock)
+    get_ticker(pair='ETH/BTC', refresh=True)
+
 
 def make_fetch_ohlcv_mock(data):
     def fetch_ohlcv_mock(pair, timeframe, since):