from difflib import Differ
from sqlite3 import connect as sql_connect, Cursor, Row
from typing import Any, Self, TypeVar, Generic
-from plomtask.exceptions import HandledException
+from plomtask.exceptions import HandledException, NotFoundException
PATH_DB_SCHEMA = 'scripts/init.sql'
EXPECTED_DB_VERSION = 0
return [row[0] for row in
self.exec(f'SELECT {column} FROM {table_name}')]
- def delete_where(self, table_name: str, key: str, target: int) -> None:
+ def delete_where(self, table_name: str, key: str,
+ target: int | str) -> None:
"""Delete from table where key == target."""
self.exec(f'DELETE FROM {table_name} WHERE {key} = ?', (target,))
table_name = ''
to_save: list[str] = []
id_: None | BaseModelId
- cache_: dict[BaseModelId, Self] = {}
+ cache_: dict[BaseModelId, Self]
+
+ def __init__(self, id_: BaseModelId | None) -> None:
+ if isinstance(id_, int) and id_ < 1:
+ msg = f'illegal {self.__class__.__name__} ID, must be >=1: {id_}'
+ raise HandledException(msg)
+ self.id_ = id_
+
+ @classmethod
+ 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],
return obj
@classmethod
- def _by_id(cls,
- db_conn: DatabaseConnection,
- id_: BaseModelId) -> tuple[Self | None, bool]:
+ def _by_id(cls, db_conn: DatabaseConnection,
+ id_: BaseModelId) -> Self | None:
"""Return instance found by ID, or None, and if from cache or not."""
- from_cache = False
obj = cls.get_cached(id_)
- if obj:
- from_cache = True
- else:
+ if not obj:
for row in db_conn.row_where(cls.table_name, 'id', id_):
obj = cls.from_table_row(db_conn, row)
obj.cache()
break
- return obj, from_cache
+ return obj
- 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:
- msg = f'illegal {self.__class__.__name__} ID, must be >=1: {id_}'
- raise HandledException(msg)
- self.id_ = id_ # type: ignore[assignment]
+ @classmethod
+ def by_id(cls, db_conn: DatabaseConnection,
+ id_: BaseModelId | None,
+ # pylint: disable=unused-argument
+ create: bool = False) -> Self:
+ """Retrieve by id_, on failure throw NotFoundException."""
+ obj = None
+ if id_ is not None:
+ obj = cls._by_id(db_conn, id_)
+ if obj:
+ return obj
+ if create:
+ obj = cls(id_)
+ return obj
+ raise NotFoundException(f'found no object of ID {id_}')
+
+ @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:
+ item = cls.by_id(db_conn, id_)
+ assert item.id_ is not None
+ items[item.id_] = item
+ return list(items.values())
def save_core(self, db_conn: DatabaseConnection,
update_with_lastrowid: bool = True) -> None:
self.id_ = cursor.lastrowid # type: ignore[assignment]
self.cache()
- @classmethod
- 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
- 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_ = {}
+ def remove(self, db_conn: DatabaseConnection) -> None:
+ """Remove from DB."""
+ assert isinstance(self.id_, int | str)
+ self.uncache()
+ db_conn.delete_where(self.table_name, 'id', self.id_)
projects / plomtask / blobdiff