kallithea Files · rhodecode/lib/vcs/utils/lazy.py

Files @ 9dd726706178

Branch filter:

Location: kallithea/rhodecode/lib/vcs/utils/lazy.py

9dd726706178 1.5 KiB text/x-python Show Annotation Show as Raw Download as Raw

Bradley M. Kuhn

Complete copyright notices for web interface; change footer to link to them.

The original copyright notice found in the footer was not accurate as it
included only one of the many copyright holders in this project. This change
creates an "about" page, which currently contains just the copyright and
license information. It links to repository for additional potential copyright
holders not listed on the about page.

Unlisted contributors are mentioned in template comments.

Html links for Kallithea is fixed and we link to Conservancy.

Display of version information in the footer is improved.

class _Missing(object):

    def __repr__(self):
        return 'no value'

    def __reduce__(self):
        return '_missing'

_missing = _Missing()


class LazyProperty(object):
    """
    Decorator for easier creation of ``property`` from potentially expensive to
    calculate attribute of the class.

    Usage::

      class Foo(object):
          @LazyProperty
          def bar(self):
              print 'Calculating self._bar'
              return 42

    Taken from http://blog.pythonisito.com/2008/08/lazy-descriptors.html and
    used widely.
    """

    def __init__(self, func):
        self._func = func
        self.__module__ = func.__module__
        self.__name__ = func.__name__
        self.__doc__ = func.__doc__

    def __get__(self, obj, klass=None):
        if obj is None:
            return self
        value = obj.__dict__.get(self.__name__, _missing)
        if value is _missing:
            value = self._func(obj)
            obj.__dict__[self.__name__] = value
        return value

import threading


class ThreadLocalLazyProperty(LazyProperty):
    """
    Same as above but uses thread local dict for cache storage.
    """

    def __get__(self, obj, klass=None):
        if obj is None:
            return self
        if not hasattr(obj, '__tl_dict__'):
            obj.__tl_dict__ = threading.local().__dict__

        value = obj.__tl_dict__.get(self.__name__, _missing)
        if value is _missing:
            value = self._func(obj)
            obj.__tl_dict__[self.__name__] = value
        return value