# -*- coding: utf-8 -*-

"""

 (c) 2018 - Copyright Red Hat Inc

 Authors:

   Pierre-Yves Chibon <pingou@pingoured.fr></pingou@pingoured.fr>

"""

from __future__ import unicode_literals, absolute_import

import gc

from functools import wraps

import pagure.lib.model_base

from pagure.config import config as pagure_config

def pagure_task(function):

    """ Simple decorator that is responsible for:

    * Adjusting the status of the task when it starts

    * Creating and cleaning up a SQLAlchemy session

    """

    @wraps(function)

    def decorated_function(self, *args, **kwargs):

        """ Decorated function, actually does the work. """

        if self is not None:

            try:

                self.update_state(state="RUNNING")

            except TypeError:

                pass

        session = pagure.lib.model_base.create_session(pagure_config["DB_URL"])

        try:

            return function(self, session, *args, **kwargs)

        except:  # noqa: E722

            # if the task has raised for any reason, we need to rollback the

            # session first to not leave open uncomitted transaction hanging

            session.rollback()

            raise

        finally:

            session.remove()

            gc_clean()

    return decorated_function

def gc_clean():

    """ Force a run of the garbage collector. """

    # https://pagure.io/pagure/issue/2302

    gc.collect()