"""Database management."""
+from __future__ import annotations
from os.path import isfile
from difflib import Differ
from sqlite3 import connect as sql_connect, Cursor, Row
-from typing import Any, Dict
+from typing import Any, Self, TypeVar, Generic
from plomtask.exceptions import HandledException
PATH_DB_SCHEMA = 'scripts/init.sql'
+EXPECTED_DB_VERSION = 0
class DatabaseFile: # pylint: disable=too-few-public-methods
self._check()
def _check(self) -> None:
- """Check file exists, and is of proper schema."""
+ """Check file exists, and is of proper DB version and schema."""
self.exists = isfile(self.path)
if self.exists:
+ self._validate_user_version()
self._validate_schema()
+ def _validate_user_version(self) -> None:
+ """Compare DB user_version with EXPECTED_DB_VERSION."""
+ sql_for_db_version = 'PRAGMA user_version'
+ with sql_connect(self.path) as conn:
+ db_version = list(conn.execute(sql_for_db_version))[0][0]
+ if db_version != EXPECTED_DB_VERSION:
+ msg = f'Wrong DB version, expected '\
+ f'{EXPECTED_DB_VERSION}, got {db_version}.'
+ raise HandledException(msg)
+
def _validate_schema(self) -> None:
"""Compare found schema with what's stored at PATH_DB_SCHEMA."""
sql_for_schema = 'SELECT sql FROM sqlite_master ORDER BY sql'
def __init__(self, db_file: DatabaseFile) -> None:
self.file = db_file
self.conn = sql_connect(self.file.path)
- self.cached_todos: Dict[int, Any] = {}
- self.cached_days: Dict[str, Any] = {}
- self.cached_process_steps: Dict[int, Any] = {}
- self.cached_processes: Dict[int, Any] = {}
- self.cached_conditions: Dict[int, Any] = {}
def commit(self) -> None:
"""Commit SQL transaction."""
return '(' + ','.join(['?'] * len(values)) + ')'
-class BaseModel:
+BaseModelId = TypeVar('BaseModelId', int, str)
+BaseModelInstance = TypeVar('BaseModelInstance', bound='BaseModel[Any]')
+
+
+class BaseModel(Generic[BaseModelId]):
"""Template for most of the models we use/derive from the DB."""
table_name = ''
to_save: list[str] = []
- id_: None | int | str
- id_type: type[Any] = int
+ id_: None | BaseModelId
+ cache_: dict[BaseModelId, Self] = {}
@classmethod
- def from_table_row(cls, db_conn: DatabaseConnection,
- row: Row | list[Any]) -> Any:
+ 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)
- assert isinstance(obj.id_, cls.id_type)
- cache = getattr(db_conn, f'cached_{cls.table_name}')
- cache[obj.id_] = obj
+ obj.cache()
return obj
@classmethod
def _by_id(cls,
db_conn: DatabaseConnection,
- id_: int | str) -> tuple[Any, bool]:
+ id_: BaseModelId) -> tuple[Self | None, bool]:
"""Return instance found by ID, or None, and if from cache or not."""
from_cache = False
- obj = None
- cache = getattr(db_conn, f'cached_{cls.table_name}')
- if id_ in cache.keys():
- obj = cache[id_]
+ 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)
- cache[id_] = obj
+ obj.cache()
break
return obj, from_cache
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_
+ self.id_ = id_ # type: ignore[assignment]
def save_core(self, db_conn: DatabaseConnection,
update_with_lastrowid: bool = True) -> None:
cursor = db_conn.exec(f'REPLACE INTO {table_name} VALUES {q_marks}',
values)
if update_with_lastrowid:
- self.id_ = cursor.lastrowid
- cache = getattr(db_conn, f'cached_{table_name}')
- cache[self.id_] = self
+ 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_ = {}
+
+ @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.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())
projects / plomtask / blobdiff