return '(' + ','.join(['?'] * len(values)) + ')'
-X = TypeVar('X', int, str)
-T = TypeVar('T', bound='BaseModel[Any]')
+BaseModelId = TypeVar('BaseModelId', int, str)
+BaseModelInstance = TypeVar('BaseModelInstance', bound='BaseModel[Any]')
-class BaseModel(Generic[X]):
+class BaseModel(Generic[BaseModelId]):
"""Template for most of the models we use/derive from the DB."""
table_name = ''
to_save: list[str] = []
- id_: None | X
- cache_: dict[X, Self] = {}
+ id_: None | BaseModelId
+ cache_: dict[BaseModelId, Self]
@classmethod
- def from_table_row(cls: type[T],
+ def get_cached(cls: type[BaseModelInstance],
+ id_: BaseModelId) -> BaseModelInstance | None:
+ """Get object of id_ from class's cache, or None if not found."""
+ # pylint: disable=consider-iterating-dictionary
+ cache = cls.get_cache()
+ if id_ in cache.keys():
+ obj = cache[id_]
+ assert isinstance(obj, cls)
+ return obj
+ return None
+
+ @classmethod
+ def empty_cache(cls) -> None:
+ """Empty class's cache."""
+ cls.cache_ = {}
+
+ @classmethod
+ def get_cache(cls: type[BaseModelInstance]) -> dict[Any, BaseModel[Any]]:
+ """Get cache dictionary, create it if not yet existing."""
+ if not hasattr(cls, 'cache_'):
+ d: dict[Any, BaseModel[Any]] = {}
+ cls.cache_ = d
+ return cls.cache_
+
+ def cache(self) -> None:
+ """Update object in class's cache."""
+ if self.id_ is None:
+ raise HandledException('Cannot cache object without ID.')
+ cache = self.__class__.get_cache()
+ cache[self.id_] = self
+
+ def uncache(self) -> None:
+ """Remove self from cache."""
+ if self.id_ is None:
+ raise HandledException('Cannot un-cache object without ID.')
+ cache = self.__class__.get_cache()
+ del cache[self.id_]
+
+ @classmethod
+ def from_table_row(cls: type[BaseModelInstance],
# pylint: disable=unused-argument
db_conn: DatabaseConnection,
- row: Row | list[Any]) -> T:
+ row: Row | list[Any]) -> BaseModelInstance:
"""Make from DB row, write to DB cache."""
obj = cls(*row)
obj.cache()
@classmethod
def _by_id(cls,
db_conn: DatabaseConnection,
- id_: X) -> tuple[Self | None, bool]:
+ id_: BaseModelId) -> tuple[Self | None, bool]:
"""Return instance found by ID, or None, and if from cache or not."""
from_cache = False
obj = cls.get_cached(id_)
break
return obj, from_cache
+ @classmethod
+ def all(cls: type[BaseModelInstance],
+ db_conn: DatabaseConnection) -> list[BaseModelInstance]:
+ """Collect all objects of class."""
+ items: dict[BaseModelId, BaseModelInstance] = {}
+ for k, v in cls.get_cache().items():
+ assert isinstance(v, cls)
+ items[k] = v
+ already_recorded = items.keys()
+ for id_ in db_conn.column_all(cls.table_name, 'id'):
+ if id_ not in already_recorded:
+ # pylint: disable=no-member
+ item = cls.by_id(db_conn, id_) # type: ignore[attr-defined]
+ items[item.id_] = item
+ return list(items.values())
+
def set_int_id(self, id_: int | None) -> None:
"""Set id_ if >= 1 or None, else fail."""
if (id_ is not None) and id_ < 1:
if update_with_lastrowid:
self.id_ = cursor.lastrowid # type: ignore[assignment]
self.cache()
-
- @classmethod
- def get_cached(cls: type[T], id_: X) -> T | None:
- """Get object of id_ from class's cache, or None if not found."""
- # pylint: disable=consider-iterating-dictionary
- if id_ in cls.cache_.keys():
- obj = cls.cache_[id_]
- assert isinstance(obj, cls)
- return obj
- return None
-
- def cache(self) -> None:
- """Update object in class's cache."""
- if self.id_ is None:
- raise HandledException('Cannot cache object without ID.')
- self.__class__.cache_[self.id_] = self
-
- def uncache(self) -> None:
- """Remove self from cache."""
- if self.id_ is None:
- raise HandledException('Cannot un-cache object without ID.')
- del self.__class__.cache_[self.id_]
-
- @classmethod
- def empty_cache(cls) -> None:
- """Empty class's cache."""
- cls.cache_ = {}