--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/web/lib/django/views/decorators/cache.py	Wed Jun 02 18:57:35 2010 +0200
@@ -0,0 +1,72 @@
+"""
+Decorator for views that tries getting the page from the cache and
+populates the cache if the page isn't in the cache yet.
+
+The cache is keyed by the URL and some data from the headers. Additionally
+there is the key prefix that is used to distinguish different cache areas
+in a multi-site setup. You could use the sites.get_current().domain, for
+example, as that is unique across a Django project.
+
+Additionally, all headers from the response's Vary header will be taken into
+account on caching -- just like the middleware does.
+"""
+
+try:
+    from functools import wraps
+except ImportError:
+    from django.utils.functional import wraps  # Python 2.4 fallback.
+
+from django.utils.decorators import decorator_from_middleware_with_args, available_attrs
+from django.utils.cache import patch_cache_control, add_never_cache_headers
+from django.middleware.cache import CacheMiddleware
+
+
+def cache_page(*args, **kwargs):
+    # We need backwards compatibility with code which spells it this way:
+    #   def my_view(): pass
+    #   my_view = cache_page(my_view, 123)
+    # and this way:
+    #   my_view = cache_page(123)(my_view)
+    # and this:
+    #   my_view = cache_page(my_view, 123, key_prefix="foo")
+    # and this:
+    #   my_view = cache_page(123, key_prefix="foo")(my_view)
+    # and possibly this way (?):
+    #   my_view = cache_page(123, my_view)
+
+    # We also add some asserts to give better error messages in case people are
+    # using other ways to call cache_page that no longer work.
+    key_prefix = kwargs.pop('key_prefix', None)
+    assert not kwargs, "The only keyword argument accepted is key_prefix"
+    if len(args) > 1:
+        assert len(args) == 2, "cache_page accepts at most 2 arguments"
+        if callable(args[0]):
+            return decorator_from_middleware_with_args(CacheMiddleware)(cache_timeout=args[1], key_prefix=key_prefix)(args[0])
+        elif callable(args[1]):
+            return decorator_from_middleware_with_args(CacheMiddleware)(cache_timeout=args[0], key_prefix=key_prefix)(args[1])
+        else:
+            assert False, "cache_page must be passed either a single argument (timeout) or a view function and a timeout"
+    else:
+        return decorator_from_middleware_with_args(CacheMiddleware)(cache_timeout=args[0], key_prefix=key_prefix)
+
+
+def cache_control(**kwargs):
+    def _cache_controller(viewfunc):
+        def _cache_controlled(request, *args, **kw):
+            response = viewfunc(request, *args, **kw)
+            patch_cache_control(response, **kwargs)
+            return response
+        return wraps(viewfunc, assigned=available_attrs(viewfunc))(_cache_controlled)
+    return _cache_controller
+
+
+def never_cache(view_func):
+    """
+    Decorator that adds headers to a response so that it will
+    never be cached.
+    """
+    def _wrapped_view_func(request, *args, **kwargs):
+        response = view_func(request, *args, **kwargs)
+        add_never_cache_headers(response)
+        return response
+    return wraps(view_func, assigned=available_attrs(view_func))(_wrapped_view_func)