ThreadRequestContext

gistfile1.py

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

import threading


class ThreadRequestContext(object):

    """A context manager that saves some per-thread state globally.
    Intended for use with Tornado's StackContext.

    Provide arbitrary data as kwargs upon creation,
    then use ThreadRequestContext.data to access it.
    """

    _state = threading.local()
    _state.data = {}

    class __metaclass__(type):
        # property() doesn't work on classmethods,
        #  see http://stackoverflow.com/q/128573/1231454

        @property
        def data(cls):
            if not hasattr(cls._state, 'data'):
                return {}
            return cls._state.data

    def __init__(self, **data):
        self._data = data

    def __enter__(self):
        self._prev_data = self.__class__.data
        self.__class__._state.data = self._data

    def __exit__(self, *exc):
        self.__class__._state.data = self._prev_data
        del self._prev_data
        return Fals