from decorator import decorator

import sqlalchemy

class Data:

    """A very simple class to save the thread pool for database requests"""

    def __init__(self):

        self.pool =  None

data = Data()

"""holds connection to the actual thread pool for the database requests"""

def setPool(pool): 

    """setting the thread pool"""

    data.pool = pool

@decorator

def runInDBPool(f,*args,**kwargs):

    """Decorator to run DB queries in Twisted's thread pool.

    If last argument is a session object, the function is called directly.

    """

    if isinstance(args[-1],sqlalchemy.orm.session.Session):

        return f(*args,**kwargs)

    else:

        return data.pool.run(f, *args, **kwargs)