sqlalchemy-dlock 0.1.1.post2

A distributed lock implementation based on SQLAlchemy

SQLAlchemy-DLock

Distributed lock based on Database and SQLAlchemy.

It currently supports locks of:

• MySQL: https://dev.mysql.com/doc/refman/8.0/en/locking-functions.html
• PostgreSQL: https://www.postgresql.org/docs/current/explicit-locking.html#ADVISORY-LOCKS

It's not stable and DO NOT use it in production.

Usages

Basic usage:

# ...
from sqlalchemy import create_engine
from sqlalchemy_dlock import make_sa_dlock

# ...

lock_key = 'user/001'

# ...

engine = create_engine('postgresql://scott:tiger@localhost/')

# ...

with engine.connect() as conn:
    with make_sa_dlock(conn, lock_key):
        # do sth...
        pass
# ...

Work with SQLAlchemy's Session:

# ...
from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker
from sqlalchemy_dlock import make_sa_dlock
# ...

lock_key = 'user/001'

# ...

engine = create_engine('postgresql://scott:tiger@localhost/')
Session = sessionmaker(bind=engine)

# ...

session = Session()

# ...

with session.bind.connect() as conn:
    with make_sa_dlock(conn, lock_key):
        # ...
        user = session.query('User').filter(id='001').one()
        user.password = 'new password'
        session.commit()
        # ...
# ...

CHANGELOG

v0.1.1

• An early version, maybe not stable enough.
• Replace black2b with crc64-iso in PostgreSQL key convert function
• Only named arguments as extra parameters allowed in Lock's implementation class

AUTHORS

• Liu Xue Yan ([e-mail])