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,))
id_: None | BaseModelId
cache_: dict[BaseModelId, Self]
- @classmethod
- def from_table_row(cls: type[BaseModelInstance],
- # pylint: disable=unused-argument
- db_conn: DatabaseConnection,
- row: Row | list[Any]) -> BaseModelInstance:
- """Make from DB row, write to DB cache."""
- obj = cls(*row)
- obj.cache()
- return obj
-
- @classmethod
- def _by_id(cls,
- db_conn: DatabaseConnection,
- 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_)
- if obj:
- from_cache = True
- else:
- 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
-
- 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:
+ 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_ # type: ignore[assignment]
-
- def save_core(self, db_conn: DatabaseConnection,
- update_with_lastrowid: bool = True) -> None:
- """Write bare-bones self (sans connected items), ensuring self.id_."""
- values = tuple([self.id_] + [getattr(self, key)
- for key in self.to_save])
- q_marks = DatabaseConnection.q_marks_from_values(values)
- table_name = self.table_name
- cursor = db_conn.exec(f'REPLACE INTO {table_name} VALUES {q_marks}',
- values)
- if update_with_lastrowid:
- self.id_ = cursor.lastrowid # type: ignore[assignment]
- self.cache()
+ self.id_ = id_
+
+ def __eq__(self, other: object) -> bool:
+ if not isinstance(other, self.__class__):
+ return False
+ to_hash_me = tuple([self.id_] +
+ [getattr(self, name) for name in self.to_save])
+ to_hash_other = tuple([other.id_] +
+ [getattr(other, name) for name in other.to_save])
+ return hash(to_hash_me) == hash(to_hash_other)
+
+ def __lt__(self, other: Any) -> bool:
+ if not isinstance(other, self.__class__):
+ msg = 'cannot compare to object of different class'
+ raise HandledException(msg)
+ assert isinstance(self.id_, int)
+ assert isinstance(other.id_, int)
+ return self.id_ < other.id_
@classmethod
def get_cached(cls: type[BaseModelInstance],
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:
del cache[self.id_]
@classmethod
- def empty_cache(cls) -> None:
- """Empty class's cache."""
- cls.cache_ = {}
+ def from_table_row(cls: type[BaseModelInstance],
+ # pylint: disable=unused-argument
+ db_conn: DatabaseConnection,
+ row: Row | list[Any]) -> BaseModelInstance:
+ """Make from DB row, write to DB cache."""
+ obj = cls(*row)
+ obj.cache()
+ return obj
+
+ @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.
+
+ First try to get from cls.cache_, only then check DB; if found,
+ put into cache.
+
+ If create=True, make anew (but do not cache yet).
+ """
+ obj = None
+ if id_ is not None:
+ obj = cls.get_cached(id_)
+ 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
+ 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."""
+ """Collect all objects of class into list.
+
+ Note that this primarily returns the contents of the cache, and only
+ _expands_ that by additional findings in the DB. This assumes the
+ cache is always instantly cleaned of any items that would be removed
+ from the DB.
+ """
items: dict[BaseModelId, BaseModelInstance] = {}
for k, v in cls.get_cache().items():
assert isinstance(v, cls)
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]
+ item = cls.by_id(db_conn, id_)
+ assert item.id_ is not None
items[item.id_] = item
return list(items.values())
- @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 save_core(self, db_conn: DatabaseConnection) -> None:
+ """Write bare-bones self (sans connected items), ensuring self.id_.
+
+ Write both to DB, and to cache. To DB, write .id_ and attributes
+ listed in cls.to_save.
+
+ Ensure self.id_ by setting it to what the DB command returns as the
+ last saved row's ID (cursor.lastrowid), EXCEPT if self.id_ already
+ exists as a 'str', which implies we do our own ID creation (so far
+ only the case with the Day class, where it's to be a date string.
+ """
+ values = tuple([self.id_] + [getattr(self, key)
+ for key in self.to_save])
+ q_marks = DatabaseConnection.q_marks_from_values(values)
+ table_name = self.table_name
+ cursor = db_conn.exec(f'REPLACE INTO {table_name} VALUES {q_marks}',
+ values)
+ if not isinstance(self.id_, str):
+ self.id_ = cursor.lastrowid # type: ignore[assignment]
+ self.cache()
+
+ def remove(self, db_conn: DatabaseConnection) -> None:
+ """Remove from DB and cache."""
+ if self.id_ is None or self.__class__.get_cached(self.id_) is None:
+ raise HandledException('cannot remove unsaved item')
+ self.uncache()
+ db_conn.delete_where(self.table_name, 'id', self.id_)
projects / plomtask / blobdiff