Add additional, typesafe getters

freqtrade/persistence/key_value_store.py

@@ -44,27 +44,6 @@ class KeyValueStore():
     Supports the types str, datetime, float and int.
     """
 
-    @staticmethod
-    def get_value(key: str) -> Optional[ValueTypes]:
-        """
-        Get the value for the given key.
-        :param key: Key to get the value for
-        """
-        kv = _KeyValueStoreModel.session.query(_KeyValueStoreModel).filter(
-            _KeyValueStoreModel.key == key).first()
-        if kv is None:
-            return None
-        if kv.value_type == ValueTypesEnum.STRING:
-            return kv.string_value
-        if kv.value_type == ValueTypesEnum.DATETIME and kv.datetime_value is not None:
-            return kv.datetime_value.replace(tzinfo=timezone.utc)
-        if kv.value_type == ValueTypesEnum.FLOAT:
-            return kv.float_value
-        if kv.value_type == ValueTypesEnum.INT:
-            return kv.int_value
-        # This should never happen unless someone messed with the database manually
-        raise ValueError(f'Unknown value type {kv.value_type}')  # pragma: no cover
-
     @staticmethod
     def store_value(key: str, value: ValueTypes) -> None:
         """
@@ -105,6 +84,79 @@ class KeyValueStore():
             _KeyValueStoreModel.session.delete(kv)
             _KeyValueStoreModel.session.commit()
 
+    @staticmethod
+    def get_value(key: str) -> Optional[ValueTypes]:
+        """
+        Get the value for the given key.
+        :param key: Key to get the value for
+        """
+        kv = _KeyValueStoreModel.session.query(_KeyValueStoreModel).filter(
+            _KeyValueStoreModel.key == key).first()
+        if kv is None:
+            return None
+        if kv.value_type == ValueTypesEnum.STRING:
+            return kv.string_value
+        if kv.value_type == ValueTypesEnum.DATETIME and kv.datetime_value is not None:
+            return kv.datetime_value.replace(tzinfo=timezone.utc)
+        if kv.value_type == ValueTypesEnum.FLOAT:
+            return kv.float_value
+        if kv.value_type == ValueTypesEnum.INT:
+            return kv.int_value
+        # This should never happen unless someone messed with the database manually
+        raise ValueError(f'Unknown value type {kv.value_type}')  # pragma: no cover
+
+    @staticmethod
+    def get_string_value(key: str) -> Optional[str]:
+        """
+        Get the value for the given key.
+        :param key: Key to get the value for
+        """
+        kv = _KeyValueStoreModel.session.query(_KeyValueStoreModel).filter(
+            _KeyValueStoreModel.key == key,
+            _KeyValueStoreModel.value_type == ValueTypesEnum.STRING).first()
+        if kv is None:
+            return None
+        return kv.string_value
+
+    @staticmethod
+    def get_datetime_value(key: str) -> Optional[datetime]:
+        """
+        Get the value for the given key.
+        :param key: Key to get the value for
+        """
+        kv = _KeyValueStoreModel.session.query(_KeyValueStoreModel).filter(
+            _KeyValueStoreModel.key == key,
+            _KeyValueStoreModel.value_type == ValueTypesEnum.DATETIME).first()
+        if kv is None or kv.datetime_value is None:
+            return None
+        return kv.datetime_value.replace(tzinfo=timezone.utc)
+
+    @staticmethod
+    def get_float_value(key: str) -> Optional[float]:
+        """
+        Get the value for the given key.
+        :param key: Key to get the value for
+        """
+        kv = _KeyValueStoreModel.session.query(_KeyValueStoreModel).filter(
+            _KeyValueStoreModel.key == key,
+            _KeyValueStoreModel.value_type == ValueTypesEnum.FLOAT).first()
+        if kv is None:
+            return None
+        return kv.float_value
+
+    @staticmethod
+    def get_int_value(key: str) -> Optional[int]:
+        """
+        Get the value for the given key.
+        :param key: Key to get the value for
+        """
+        kv = _KeyValueStoreModel.session.query(_KeyValueStoreModel).filter(
+            _KeyValueStoreModel.key == key,
+            _KeyValueStoreModel.value_type == ValueTypesEnum.INT).first()
+        if kv is None:
+            return None
+        return kv.int_value
+
 
 def set_startup_time():
     """

tests/persistence/test_key_value_store.py

@@ -17,9 +17,18 @@ def test_key_value_store(time_machine):
     KeyValueStore.store_value("test_int", 15)
 
     assert KeyValueStore.get_value("test") == "testStringValue"
+    assert KeyValueStore.get_value("test") == "testStringValue"
+    assert KeyValueStore.get_string_value("test") == "testStringValue"
     assert KeyValueStore.get_value("test_dt") == datetime.now(timezone.utc)
+    assert KeyValueStore.get_datetime_value("test_dt") == datetime.now(timezone.utc)
+    assert KeyValueStore.get_string_value("test_dt") is None
+    assert KeyValueStore.get_float_value("test_dt") is None
+    assert KeyValueStore.get_int_value("test_dt") is None
     assert KeyValueStore.get_value("test_float") == 22.51
+    assert KeyValueStore.get_float_value("test_float") == 22.51
     assert KeyValueStore.get_value("test_int") == 15
+    assert KeyValueStore.get_int_value("test_int") == 15
+    assert KeyValueStore.get_datetime_value("test_int") is None
 
     time_machine.move_to(start + timedelta(days=20, hours=5), tick=False)
     assert KeyValueStore.get_value("test_dt") != datetime.now(timezone.utc)