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)