stable/freqtrade/persistence/models.py
2022-05-19 06:56:34 +02:00

73 lines
2.3 KiB
Python

"""
This module contains the class to persist trades into SQLite
"""
import logging
from sqlalchemy import create_engine, inspect
from sqlalchemy.exc import NoSuchModuleError
from sqlalchemy.orm import scoped_session, sessionmaker
from sqlalchemy.pool import StaticPool
from freqtrade.exceptions import OperationalException
from freqtrade.persistence.base import _DECL_BASE
from freqtrade.persistence.migrations import check_migrate
from freqtrade.persistence.pairlock import PairLock
from freqtrade.persistence.trade_model import Order, Trade
logger = logging.getLogger(__name__)
_SQL_DOCS_URL = 'http://docs.sqlalchemy.org/en/latest/core/engines.html#database-urls'
def init_db(db_url: str) -> None:
"""
Initializes this module with the given config,
registers all known command handlers
and starts polling for message updates
:param db_url: Database to use
:return: None
"""
kwargs = {}
if db_url == 'sqlite:///':
raise OperationalException(
f'Bad db-url {db_url}. For in-memory database, please use `sqlite://`.')
if db_url == 'sqlite://':
kwargs.update({
'poolclass': StaticPool,
})
# Take care of thread ownership
if db_url.startswith('sqlite://'):
kwargs.update({
'connect_args': {'check_same_thread': False},
})
try:
engine = create_engine(db_url, future=True, **kwargs)
except NoSuchModuleError:
raise OperationalException(f"Given value for db_url: '{db_url}' "
f"is no valid database URL! (See {_SQL_DOCS_URL})")
# https://docs.sqlalchemy.org/en/13/orm/contextual.html#thread-local-scope
# Scoped sessions proxy requests to the appropriate thread-local session.
# We should use the scoped_session object - not a seperately initialized version
Trade._session = scoped_session(sessionmaker(bind=engine, autoflush=True))
Trade.query = Trade._session.query_property()
Order.query = Trade._session.query_property()
PairLock.query = Trade._session.query_property()
previous_tables = inspect(engine).get_table_names()
_DECL_BASE.metadata.create_all(engine)
check_migrate(engine, decl_base=_DECL_BASE, previous_tables=previous_tables)
def cleanup_db() -> None:
"""
Flushes all pending operations to disk.
:return: None
"""
Trade.commit()