models.py 文件源码

def url_by_alias(page_alias):
        """
        Try to read page url from cache. If it's missing then try to find
        matching page that could be missing in cache. If page is found
        then refresh all url list since it's too old.
        If no matching is found then return None so we can throw any
        exception we want in other places
        """
        if page_alias:
            url_to_alias = cache.get(cachekeys.URL_LIST_CACHE)
            if url_to_alias is None:
                url_to_alias = PageURLCache.refresh()
            url = url_to_alias.get(page_alias)
        else:
            url = None
        return url


# Models: