Add initial version of key value store

freqtrade/persistence/__init__.py

@@ -1,5 +1,6 @@
 # flake8: noqa: F401
 
+from freqtrade.persistence.key_value_store import KeyValueStore
 from freqtrade.persistence.models import init_db
 from freqtrade.persistence.pairlock_middleware import PairLocks
 from freqtrade.persistence.trade_model import LocalTrade, Order, Trade

freqtrade/persistence/key_value_store.py

@@ -0,0 +1,97 @@
+from datetime import datetime, timezone
+from enum import Enum
+from typing import ClassVar, Optional, Union
+
+from sqlalchemy import String
+from sqlalchemy.orm import Mapped, mapped_column
+
+from freqtrade.persistence.base import ModelBase, SessionType
+
+
+ValueTypes = Union[str, datetime, float, int]
+
+
+class ValueTypesEnum(str, Enum):
+    STRING = 'str'
+    DATETIME = 'datetime'
+    FLOAT = 'float'
+    INT = 'int'
+
+
+class _KeyValueStoreModel(ModelBase):
+    """
+    Pair Locks database model.
+    """
+    __tablename__ = 'KeyValueStore'
+    session: ClassVar[SessionType]
+
+    id: Mapped[int] = mapped_column(primary_key=True)
+
+    key: Mapped[str] = mapped_column(String(25), nullable=False, index=True)
+
+    value_type: Mapped[ValueTypesEnum] = mapped_column(String(25), nullable=False)
+
+    string_value: Mapped[Optional[str]]
+    datetime_value: Mapped[Optional[datetime]]
+    float_value: Mapped[Optional[float]]
+    int_value: Mapped[Optional[int]]
+
+
+class KeyValueStore():
+
+    @staticmethod
+    def get_value(key: str) -> Optional[ValueTypes]:
+        """
+        Get the value for the given key.
+        """
+        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:
+        """
+        Store the given value for the given key.
+        """
+        kv = _KeyValueStoreModel.session.query(_KeyValueStoreModel).filter(
+            _KeyValueStoreModel.key == key).first()
+        if kv is None:
+            kv = _KeyValueStoreModel(key=key)
+        if isinstance(value, str):
+            kv.value_type = ValueTypesEnum.STRING
+            kv.string_value = value
+        elif isinstance(value, datetime):
+            kv.value_type = ValueTypesEnum.DATETIME
+            kv.datetime_value = value
+        elif isinstance(value, float):
+            kv.value_type = ValueTypesEnum.FLOAT
+            kv.float_value = value
+        elif isinstance(value, int):
+            kv.value_type = ValueTypesEnum.INT
+            kv.int_value = value
+        else:
+            raise ValueError(f'Unknown value type {kv.value_type}')
+        _KeyValueStoreModel.session.add(kv)
+        _KeyValueStoreModel.session.commit()
+
+    @staticmethod
+    def delete_value(key: str) -> None:
+        """
+        Delete the value for the given key.
+        """
+        kv = _KeyValueStoreModel.session.query(_KeyValueStoreModel).filter(
+            _KeyValueStoreModel.key == key).first()
+        if kv is not None:
+            _KeyValueStoreModel.session.delete(kv)
+            _KeyValueStoreModel.session.commit()

freqtrade/persistence/models.py

@@ -13,6 +13,7 @@ from sqlalchemy.pool import StaticPool
 
 from freqtrade.exceptions import OperationalException
 from freqtrade.persistence.base import ModelBase
+from freqtrade.persistence.key_value_store import _KeyValueStoreModel
 from freqtrade.persistence.migrations import check_migrate
 from freqtrade.persistence.pairlock import PairLock
 from freqtrade.persistence.trade_model import Order, Trade
@@ -76,6 +77,7 @@ def init_db(db_url: str) -> None:
         bind=engine, autoflush=False), scopefunc=get_request_or_thread_id)
     Order.session = Trade.session
     PairLock.session = Trade.session
+    _KeyValueStoreModel.session = Trade.session
 
     previous_tables = inspect(engine).get_table_names()
     ModelBase.metadata.create_all(engine)