76 lines
2.3 KiB
Python
76 lines
2.3 KiB
Python
# coding: utf-8
|
|
"""
|
|
This module contains functions related to the database.
|
|
"""
|
|
from __future__ import absolute_import, print_function, unicode_literals
|
|
|
|
import sqlite3
|
|
|
|
from contextlib import contextmanager
|
|
|
|
from sqlalchemy import event, create_engine
|
|
from sqlalchemy.engine import Engine
|
|
from sqlalchemy.orm import sessionmaker
|
|
from sqlalchemy.exc import OperationalError, SQLAlchemyError
|
|
|
|
import flatisfy.models.flat # noqa: F401
|
|
from flatisfy.database.base import BASE
|
|
from flatisfy.database.whooshalchemy import IndexService
|
|
|
|
|
|
@event.listens_for(Engine, "connect")
|
|
def set_sqlite_pragma(dbapi_connection, _):
|
|
"""
|
|
Auto enable foreign keys for SQLite.
|
|
"""
|
|
# Play well with other DB backends
|
|
if isinstance(dbapi_connection, sqlite3.Connection):
|
|
cursor = dbapi_connection.cursor()
|
|
cursor.execute("PRAGMA foreign_keys=ON")
|
|
cursor.close()
|
|
|
|
|
|
def init_db(database_uri=None, search_db_uri=None):
|
|
"""
|
|
Initialize the database, ensuring tables exist etc.
|
|
|
|
:param database_uri: An URI describing an engine to use. Defaults to
|
|
in-memory SQLite database.
|
|
:param search_db_uri: Path to the Whoosh index file to use.
|
|
:return: A tuple of an SQLAlchemy session maker and the created engine.
|
|
"""
|
|
if database_uri is None:
|
|
database_uri = "sqlite:///:memory:"
|
|
|
|
engine = create_engine(database_uri)
|
|
BASE.metadata.create_all(engine, checkfirst=True)
|
|
Session = sessionmaker(bind=engine) # pylint: disable=locally-disabled,invalid-name
|
|
|
|
if search_db_uri:
|
|
index_service = IndexService(
|
|
whoosh_base=search_db_uri
|
|
)
|
|
index_service.register_class(flatisfy.models.flat.Flat)
|
|
|
|
@contextmanager
|
|
def get_session():
|
|
# pylint: disable=locally-disabled,line-too-long
|
|
"""
|
|
Provide a transactional scope around a series of operations.
|
|
|
|
From [1].
|
|
[1]: http://docs.sqlalchemy.org/en/latest/orm/session_basics.html#when-do-i-construct-a-session-when-do-i-commit-it-and-when-do-i-close-it.
|
|
"""
|
|
# pylint: enable=line-too-long,locally-disabled
|
|
session = Session()
|
|
try:
|
|
yield session
|
|
session.commit()
|
|
except SQLAlchemyError:
|
|
session.rollback()
|
|
raise
|
|
finally:
|
|
session.close()
|
|
|
|
return get_session
|