removing controller/serializer code from wsgi.py; updating other code to use new modules

nova/api/direct.py

@@ -42,6 +42,7 @@ from nova import exception
 from nova import flags
 from nova import utils
 from nova import wsgi
+import nova.api.openstack.wsgi
 
 
 # Global storage for registering modules.
@@ -251,7 +252,7 @@ class Reflection(object):
         return self._methods[method]
 
 
-class ServiceWrapper(wsgi.Controller):
+class ServiceWrapper(object):
     """Wrapper to dynamically povide a WSGI controller for arbitrary objects.
 
     With lightweight introspection allows public methods on the object to
@@ -265,7 +266,7 @@ class ServiceWrapper(wsgi.Controller):
     def __init__(self, service_handle):
         self.service_handle = service_handle
 
-    @webob.dec.wsgify(RequestClass=wsgi.Request)
+    @webob.dec.wsgify(RequestClass=nova.api.openstack.wsgi.Request)
     def __call__(self, req):
         arg_dict = req.environ['wsgiorg.routing_args'][1]
         action = arg_dict['action']
@@ -289,8 +290,11 @@ class ServiceWrapper(wsgi.Controller):
 
         try:
             content_type = req.best_match_content_type()
-            default_xmlns = self.get_default_xmlns(req)
+            serializer = {
-            return self._serialize(result, content_type, default_xmlns)
+                'application/xml': nova.api.openstack.wsgi.XMLSerializer(),
+                'application/json': nova.api.openstack.wsgi.JSONSerializer(),
+            }[content_type]
+            return serializer.serialize(result)
         except:
             raise exception.Error("returned non-serializable type: %s"
                                   % result)

nova/api/openstack/common.py

@@ -23,7 +23,6 @@ import webob
 from nova import exception
 from nova import flags
 from nova import log as logging
-from nova import wsgi
 
 
 LOG = logging.getLogger('nova.api.openstack.common')
@@ -146,9 +145,3 @@ def get_id_from_href(href):
     except:
         LOG.debug(_("Error extracting id from href: %s") % href)
         raise webob.exc.HTTPBadRequest(_('could not parse id from href'))
-
-
-class OpenstackController(wsgi.Controller):
-    def get_default_xmlns(self, req):
-        # Use V10 by default
-        return XML_NS_V10

nova/api/openstack/consoles.py

@@ -44,11 +44,10 @@ def _translate_detail_keys(cons):
 
 
 class Controller(object):
-    """The Consoles Controller for the Openstack API"""
+    """The Consoles controller for the Openstack API"""
 
     def __init__(self):
         self.console_api = console.API()
-        super(Controller, self).__init__()
 
     def index(self, req, server_id):
         """Returns a list of consoles for this instance"""

nova/api/openstack/contrib/volumes.py

@@ -22,7 +22,6 @@ from nova import exception
 from nova import flags
 from nova import log as logging
 from nova import volume
-from nova import wsgi
 from nova.api.openstack import common
 from nova.api.openstack import extensions
 from nova.api.openstack import faults
@@ -64,7 +63,7 @@ def _translate_volume_summary_view(context, vol):
     return d
 
 
-class VolumeController(wsgi.Controller):
+class VolumeController(object):
     """The Volumes API controller for the OpenStack API."""
 
     _serialization_metadata = {
@@ -124,15 +123,14 @@ class VolumeController(wsgi.Controller):
         res = [entity_maker(context, vol) for vol in limited_list]
         return {'volumes': res}
 
-    def create(self, req):
+    def create(self, req, body):
         """Creates a new volume."""
         context = req.environ['nova.context']
 
-        env = self._deserialize(req.body, req.get_content_type())
+        if not body:
-        if not env:
             return faults.Fault(exc.HTTPUnprocessableEntity())
 
-        vol = env['volume']
+        vol = body['volume']
         size = vol['size']
         LOG.audit(_("Create volume of %s GB"), size, context=context)
         new_volume = self.volume_api.create(context, size,
@@ -175,7 +173,7 @@ def _translate_attachment_summary_view(_context, vol):
     return d
 
 
-class VolumeAttachmentController(wsgi.Controller):
+class VolumeAttachmentController(object):
     """The volume attachment API controller for the Openstack API.
 
     A child resource of the server.  Note that we use the volume id
@@ -219,17 +217,16 @@ class VolumeAttachmentController(wsgi.Controller):
         return {'volumeAttachment': _translate_attachment_detail_view(context,
                                                                       vol)}
 
-    def create(self, req, server_id):
+    def create(self, req, server_id, body):
         """Attach a volume to an instance."""
         context = req.environ['nova.context']
 
-        env = self._deserialize(req.body, req.get_content_type())
+        if not body:
-        if not env:
             return faults.Fault(exc.HTTPUnprocessableEntity())
 
         instance_id = server_id
-        volume_id = env['volumeAttachment']['volumeId']
+        volume_id = body['volumeAttachment']['volumeId']
-        device = env['volumeAttachment']['device']
+        device = body['volumeAttachment']['device']
 
         msg = _("Attach volume %(volume_id)s to instance %(server_id)s"
                 " at %(device)s") % locals()
@@ -259,7 +256,7 @@ class VolumeAttachmentController(wsgi.Controller):
         # TODO(justinsb): How do I return "accepted" here?
         return {'volumeAttachment': attachment}
 
-    def update(self, _req, _server_id, _id):
+    def update(self, req, server_id, id, body):
         """Update a volume attachment.  We don't currently support this."""
         return faults.Fault(exc.HTTPBadRequest())
 

nova/api/openstack/extensions.py

@@ -27,9 +27,10 @@ import webob.exc
 from nova import exception
 from nova import flags
 from nova import log as logging
-from nova import wsgi
+from nova import wsgi as base_wsgi
 from nova.api.openstack import common
 from nova.api.openstack import faults
+from nova.api.openstack import wsgi
 
 
 LOG = logging.getLogger('extensions')
@@ -116,28 +117,34 @@ class ExtensionDescriptor(object):
         return response_exts
 
 
-class ActionExtensionController(common.OpenstackController):
+class ActionExtensionController(object):
-
     def __init__(self, application):
-
         self.application = application
         self.action_handlers = {}
 
     def add_action(self, action_name, handler):
         self.action_handlers[action_name] = handler
 
-    def action(self, req, id):
+    def action(self, req, id, body):
-
-        input_dict = self._deserialize(req.body, req.get_content_type())
         for action_name, handler in self.action_handlers.iteritems():
-            if action_name in input_dict:
+            if action_name in body:
-                return handler(input_dict, req, id)
+                return handler(body, req, id)
         # no action handler found (bump to downstream application)
         res = self.application
         return res
 
 
-class ResponseExtensionController(common.OpenstackController):
+class ActionExtensionResource(wsgi.Resource):
+
+    def __init__(self, application):
+        controller = ActionExtensionController(application)
+        super(ActionExtensionResource, self).__init__(controller)
+
+    def add_action(self, action_name, handler):
+        self.controller.add_action(action_name, handler)
+
+
+class ResponseExtensionController(object):
 
     def __init__(self, application):
         self.application = application
@@ -157,7 +164,11 @@ class ResponseExtensionController(common.OpenstackController):
                 headers = res.headers
             except AttributeError:
                 default_xmlns = None
-                body = self._serialize(res, content_type, default_xmlns)
+                serializer = {
+                    'application/xml': wsgi.XMLSerializer(),
+                    'application/json': wsgi.JSONSerializer(),
+                }[content_type]
+                body = serializer.serialize(res)
                 headers = {"Content-Type": content_type}
             res = webob.Response()
             res.body = body
@@ -165,7 +176,17 @@ class ResponseExtensionController(common.OpenstackController):
         return res
 
 
-class ExtensionController(common.OpenstackController):
+class ResponseExtensionResource(wsgi.Resource):
+
+    def __init__(self, application):
+        controller = ResponseExtensionController(application)
+        super(ResponseExtensionResource, self).__init__(controller)
+
+    def add_handler(self, handler):
+        self.controller.add_handler(handler)
+
+
+class ExtensionController(object):
 
     def __init__(self, extension_manager):
         self.extension_manager = extension_manager
@@ -198,7 +219,7 @@ class ExtensionController(common.OpenstackController):
         raise faults.Fault(webob.exc.HTTPNotFound())
 
 
-class ExtensionMiddleware(wsgi.Middleware):
+class ExtensionMiddleware(base_wsgi.Middleware):
     """Extensions middleware for WSGI."""
     @classmethod
     def factory(cls, global_config, **local_config):
@@ -207,43 +228,43 @@ class ExtensionMiddleware(wsgi.Middleware):
             return cls(app, **local_config)
         return _factory
 
-    def _action_ext_controllers(self, application, ext_mgr, mapper):
+    def _action_ext_resources(self, application, ext_mgr, mapper):
-        """Return a dict of ActionExtensionController-s by collection."""
+        """Return a dict of ActionExtensionResource objects by collection."""
-        action_controllers = {}
+        action_resources = {}
         for action in ext_mgr.get_actions():
-            if not action.collection in action_controllers.keys():
+            if not action.collection in action_resources.keys():
-                controller = ActionExtensionController(application)
+                resource = ActionExtensionResource(application)
                 mapper.connect("/%s/:(id)/action.:(format)" %
                                 action.collection,
                                 action='action',
-                                controller=controller,
+                                controller=resource,
                                 conditions=dict(method=['POST']))
                 mapper.connect("/%s/:(id)/action" % action.collection,
                                 action='action',
-                                controller=controller,
+                                controller=resource,
                                 conditions=dict(method=['POST']))
-                action_controllers[action.collection] = controller
+                action_resources[action.collection] = resource
 
-        return action_controllers
+        return action_resources
 
-    def _response_ext_controllers(self, application, ext_mgr, mapper):
+    def _response_ext_resources(self, application, ext_mgr, mapper):
-        """Returns a dict of ResponseExtensionController-s by collection."""
+        """Returns a dict of ResponseExtensionResource objects by collection."""
-        response_ext_controllers = {}
+        response_ext_resources = {}
         for resp_ext in ext_mgr.get_response_extensions():
-            if not resp_ext.key in response_ext_controllers.keys():
+            if not resp_ext.key in response_ext_resources.keys():
-                controller = ResponseExtensionController(application)
+                resource = ResponseExtensionResource(application)
                 mapper.connect(resp_ext.url_route + '.:(format)',
                                 action='process',
-                                controller=controller,
+                                controller=resource,
                                 conditions=resp_ext.conditions)
 
                 mapper.connect(resp_ext.url_route,
                                 action='process',
-                                controller=controller,
+                                controller=resource,
                                 conditions=resp_ext.conditions)
-                response_ext_controllers[resp_ext.key] = controller
+                response_ext_resources[resp_ext.key] = resource
 
-        return response_ext_controllers
+        return response_ext_resources
 
     def __init__(self, application, ext_mgr=None):
 
@@ -258,21 +279,21 @@ class ExtensionMiddleware(wsgi.Middleware):
             LOG.debug(_('Extended resource: %s'),
                         resource.collection)
             mapper.resource(resource.collection, resource.collection,
-                            controller=resource.controller,
+                            controller=wsgi.Resource(resource.controller),
                             collection=resource.collection_actions,
                             member=resource.member_actions,
                             parent_resource=resource.parent)
 
         # extended actions
-        action_controllers = self._action_ext_controllers(application, ext_mgr,
+        action_resources = self._action_ext_resources(application, ext_mgr,
                                                         mapper)
         for action in ext_mgr.get_actions():
             LOG.debug(_('Extended action: %s'), action.action_name)
-            controller = action_controllers[action.collection]
+            resource = action_resources[action.collection]
-            controller.add_action(action.action_name, action.handler)
+            resource.add_action(action.action_name, action.handler)
 
         # extended responses
-        resp_controllers = self._response_ext_controllers(application, ext_mgr,
+        resp_controllers = self._response_ext_resources(application, ext_mgr,
                                                             mapper)
         for response_ext in ext_mgr.get_response_extensions():
             LOG.debug(_('Extended response: %s'), response_ext.key)
@@ -422,7 +443,7 @@ class ExtensionManager(object):
 
 
 class ResponseExtension(object):
-    """Add data to responses from core nova OpenStack API controllers."""
+    """Add data to responses from core nova OpenStack API resources."""
 
     def __init__(self, method, url_route, handler):
         self.url_route = url_route
@@ -432,7 +453,7 @@ class ResponseExtension(object):
 
 
 class ActionExtension(object):
-    """Add custom actions to core nova OpenStack API controllers."""
+    """Add custom actions to core nova OpenStack API resources."""
 
     def __init__(self, collection, action_name, handler):
         self.collection = collection

nova/api/openstack/faults.py

@@ -19,8 +19,7 @@
 import webob.dec
 import webob.exc
 
-from nova import wsgi
+from nova.api.openstack import wsgi
-from nova.api.openstack import common
 
 
 class Fault(webob.exc.HTTPException):
@@ -55,13 +54,21 @@ class Fault(webob.exc.HTTPException):
         if code == 413:
             retry = self.wrapped_exc.headers['Retry-After']
             fault_data[fault_name]['retryAfter'] = retry
+
         # 'code' is an attribute on the fault tag itself
-        metadata = {'application/xml': {'attributes': {fault_name: 'code'}}}
+        metadata = {'attributes': {fault_name: 'code'}}
-        default_xmlns = common.XML_NS_V10
+
-        serializer = wsgi.Serializer(metadata, default_xmlns)
         content_type = req.best_match_content_type()
-        self.wrapped_exc.body = serializer.serialize(fault_data, content_type)
+
+        serializer = {
+            'application/xml': wsgi.XMLSerializer(metadata=metadata,
+                                                  xmlns=wsgi.XMLNS_V10),
+            'application/json': wsgi.JSONSerializer(),
+        }[content_type]
+
+        self.wrapped_exc.body = serializer.serialize(fault_data)
         self.wrapped_exc.content_type = content_type
+
         return self.wrapped_exc
 
 
@@ -70,14 +77,6 @@ class OverLimitFault(webob.exc.HTTPException):
     Rate-limited request response.
     """
 
-    _serialization_metadata = {
-        "application/xml": {
-            "attributes": {
-                "overLimitFault": "code",
-            },
-        },
-    }
-
     def __init__(self, message, details, retry_time):
         """
         Initialize new `OverLimitFault` with relevant information.
@@ -97,8 +96,16 @@ class OverLimitFault(webob.exc.HTTPException):
         Return the wrapped exception with a serialized body conforming to our
         error format.
         """
-        serializer = wsgi.Serializer(self._serialization_metadata)
         content_type = request.best_match_content_type()
-        content = serializer.serialize(self.content, content_type)
+        metadata = {"attributes": {"overLimitFault": "code"}}
+
+        serializer = {
+            'application/xml': wsgi.XMLSerializer(metadata=metadata,
+                                                  xmlns=wsgi.XMLNS_V10),
+            'application/json': wsgi.JSONSerializer(),
+        }[content_type]
+
+        content = serializer.serialize(self.content)
         self.wrapped_exc.body = content
+
         return self.wrapped_exc

nova/api/openstack/image_metadata.py

@@ -20,7 +20,6 @@ from webob import exc
 from nova import flags
 from nova import quota
 from nova import utils
-from nova import wsgi
 from nova.api.openstack import faults
 from nova.api.openstack import wsgi
 

nova/api/openstack/images.py

@@ -31,7 +31,7 @@ FLAGS = flags.FLAGS
 
 
 class Controller(object):
-    """Base `wsgi.Controller` for retrieving/displaying images."""
+    """Base controller for retrieving/displaying images."""
 
     def __init__(self, image_service=None, compute_service=None):
         """Initialize new `ImageController`.
@@ -99,21 +99,20 @@ class Controller(object):
         self._image_service.delete(context, image_id)
         return webob.exc.HTTPNoContent()
 
-    def create(self, req):
+    def create(self, req, body):
         """Snapshot a server instance and save the image.
 
         :param req: `wsgi.Request` object
         """
         context = req.environ['nova.context']
         content_type = req.get_content_type()
-        image = self._deserialize(req.body, content_type)
 
-        if not image:
+        if not body:
             raise webob.exc.HTTPBadRequest()
 
         try:
-            server_id = image["image"]["serverId"]
+            server_id = body["image"]["serverId"]
-            image_name = image["image"]["name"]
+            image_name = body["image"]["name"]
         except KeyError:
             raise webob.exc.HTTPBadRequest()
 

nova/api/openstack/versions.py

@@ -18,13 +18,27 @@
 import webob
 import webob.dec
 
-from nova import wsgi
+from nova import wsgi as base_wsgi
 import nova.api.openstack.views.versions
+from nova.api.openstack import wsgi
 
 
-class Versions(wsgi.Application):
+class Versions(wsgi.Resource, base_wsgi.Application):
-    @webob.dec.wsgify(RequestClass=wsgi.Request)
+    def __init__(self):
-    def __call__(self, req):
+        metadata = {
+            "attributes": {
+                "version": ["status", "id"],
+                "link": ["rel", "href"],
+            }
+        }
+
+        serializers = {
+            'application/xml': wsgi.XMLSerializer(metadata=metadata),
+        }
+
+        super(Versions, self).__init__(None, serializers=serializers)
+
+    def dispatch(self, request, *args):
         """Respond to a request for all OpenStack API versions."""
         version_objs = [
             {
@@ -37,24 +51,6 @@ class Versions(wsgi.Application):
             },
         ]
 
-        builder = nova.api.openstack.views.versions.get_view_builder(req)
+        builder = nova.api.openstack.views.versions.get_view_builder(request)
         versions = [builder.build(version) for version in version_objs]
-        response = dict(versions=versions)
+        return dict(versions=versions)
-
-        metadata = {
-            "application/xml": {
-                "attributes": {
-                    "version": ["status", "id"],
-                    "link": ["rel", "href"],
-                }
-            }
-        }
-
-        content_type = req.best_match_content_type()
-        body = wsgi.Serializer(metadata).serialize(response, content_type)
-
-        response = webob.Response()
-        response.content_type = content_type
-        response.body = body
-
-        return response

nova/api/openstack/wsgi.py

@@ -206,8 +206,7 @@ class Resource(object):
         except exception.InvalidContentType:
             return webob.exc.HTTPBadRequest(_("Unsupported Content-Type"))
 
-        controller_method = getattr(self.controller, action)
+        result = self.dispatch(request, action, action_args)
-        result = controller_method(req=request, **action_args)
 
         response = self.serialize_response(accept, result)
 
@@ -222,6 +221,10 @@ class Resource(object):
 
         return response
 
+    def dispatch(self, request, action, action_args):
+        controller_method = getattr(self.controller, action)
+        return controller_method(req=request, **action_args)
+
     def serialize_response(self, content_type, response_body):
         """Serialize a dict into a string and wrap in a wsgi.Request object.
 
@@ -253,7 +256,7 @@ class Resource(object):
 
         """
         action_args = self.get_action_args(request.environ)
-        action = action_args.pop('action')
+        action = action_args.pop('action', None)
 
         if request.method.lower() in ('post', 'put'):
             if len(request.body) == 0:
@@ -275,6 +278,7 @@ class Resource(object):
         return request.best_match_content_type()
 
     def get_action_args(self, request_environment):
+        try:
             args = request_environment['wsgiorg.routing_args'][1].copy()
 
             del args['controller']
@@ -284,6 +288,9 @@ class Resource(object):
 
             return args
 
+        except KeyError:
+            return {}
+
     def get_deserializer(self, content_type):
         try:
             return self.deserializers[content_type]

nova/objectstore/s3server.py

@@ -81,7 +81,7 @@ class S3Application(wsgi.Router):
         super(S3Application, self).__init__(mapper)
 
 
-class BaseRequestHandler(wsgi.Controller):
+class BaseRequestHandler(object):
     """Base class emulating Tornado's web framework pattern in WSGI.
 
     This is a direct port of Tornado's implementation, so some key decisions

nova/tests/api/openstack/extensions/foxinsocks.py

@@ -17,12 +17,10 @@
 
 import json
 
-from nova import wsgi
-
 from nova.api.openstack import extensions
 
 
-class FoxInSocksController(wsgi.Controller):
+class FoxInSocksController(object):
 
     def index(self, req):
         return "Try to say this Mr. Knox, sir..."

nova/tests/api/openstack/test_extensions.py

@@ -26,15 +26,15 @@ from nova import flags
 from nova.api import openstack
 from nova.api.openstack import extensions
 from nova.api.openstack import flavors
+from nova.api.openstack import wsgi
 from nova.tests.api.openstack import fakes
-import nova.wsgi
 
 FLAGS = flags.FLAGS
 
 response_body = "Try to say this Mr. Knox, sir..."
 
 
-class StubController(nova.wsgi.Controller):
+class StubController(object):
 
     def __init__(self, body):
         self.body = body

nova/tests/api/test_wsgi.py

@@ -67,57 +67,3 @@ class Test(test.TestCase):
         self.assertEqual(result.body, "Router result")
         result = webob.Request.blank('/bad').get_response(Router())
         self.assertNotEqual(result.body, "Router result")
-
-
-class ControllerTest(test.TestCase):
-
-    class TestRouter(wsgi.Router):
-
-        class TestController(wsgi.Controller):
-
-            _serialization_metadata = {
-                'application/xml': {
-                    "attributes": {
-                        "test": ["id"]}}}
-
-            def show(self, req, id):  # pylint: disable=W0622,C0103
-                return {"test": {"id": id}}
-
-        def __init__(self):
-            mapper = routes.Mapper()
-            mapper.resource("test", "tests", controller=self.TestController())
-            wsgi.Router.__init__(self, mapper)
-
-    def test_show(self):
-        request = wsgi.Request.blank('/tests/123')
-        result = request.get_response(self.TestRouter())
-        self.assertEqual(json.loads(result.body), {"test": {"id": "123"}})
-
-    def test_response_content_type_from_accept_xml(self):
-        request = webob.Request.blank('/tests/123')
-        request.headers["Accept"] = "application/xml"
-        result = request.get_response(self.TestRouter())
-        self.assertEqual(result.headers["Content-Type"], "application/xml")
-
-    def test_response_content_type_from_accept_json(self):
-        request = wsgi.Request.blank('/tests/123')
-        request.headers["Accept"] = "application/json"
-        result = request.get_response(self.TestRouter())
-        self.assertEqual(result.headers["Content-Type"], "application/json")
-
-    def test_response_content_type_from_query_extension_xml(self):
-        request = wsgi.Request.blank('/tests/123.xml')
-        result = request.get_response(self.TestRouter())
-        self.assertEqual(result.headers["Content-Type"], "application/xml")
-
-    def test_response_content_type_from_query_extension_json(self):
-        request = wsgi.Request.blank('/tests/123.json')
-        result = request.get_response(self.TestRouter())
-        self.assertEqual(result.headers["Content-Type"], "application/json")
-
-    def test_response_content_type_default_when_unsupported(self):
-        request = wsgi.Request.blank('/tests/123.unsupported')
-        request.headers["Accept"] = "application/unsupported1"
-        result = request.get_response(self.TestRouter())
-        self.assertEqual(result.status_int, 200)
-        self.assertEqual(result.headers["Content-Type"], "application/json")

nova/wsgi.py

@@ -82,36 +82,7 @@ class Server(object):
 
 
 class Request(webob.Request):
-
+    pass
-    def best_match_content_type(self):
-        """Determine the most acceptable content-type.
-
-        Based on the query extension then the Accept header.
-
-        """
-        parts = self.path.rsplit('.', 1)
-
-        if len(parts) > 1:
-            format = parts[1]
-            if format in ['json', 'xml']:
-                return 'application/{0}'.format(parts[1])
-
-        ctypes = ['application/json', 'application/xml']
-        bm = self.accept.best_match(ctypes)
-
-        return bm or 'application/json'
-
-    def get_content_type(self):
-        allowed_types = ("application/xml", "application/json")
-        if not "Content-Type" in self.headers:
-            msg = _("Missing Content-Type")
-            LOG.debug(msg)
-            raise webob.exc.HTTPBadRequest(msg)
-        type = self.content_type
-        if type in allowed_types:
-            return type
-        LOG.debug(_("Wrong Content-Type: %s") % type)
-        raise webob.exc.HTTPBadRequest("Invalid content type")
 
 
 class Application(object):
@@ -286,7 +257,7 @@ class Router(object):
 
         Each route in `mapper` must specify a 'controller', which is a
         WSGI app to call.  You'll probably want to specify an 'action' as
-        well and have your controller be a wsgi.Controller, who will route
+        well and have your controller be a controller, who will route
         the request to the action method.
 
         Examples:
@@ -335,223 +306,6 @@ class Router(object):
         return app
 
 
-class Controller(object):
-    """WSGI app that dispatched to methods.
-
-    WSGI app that reads routing information supplied by RoutesMiddleware
-    and calls the requested action method upon itself.  All action methods
-    must, in addition to their normal parameters, accept a 'req' argument
-    which is the incoming wsgi.Request.  They raise a webob.exc exception,
-    or return a dict which will be serialized by requested content type.
-
-    """
-
-    @webob.dec.wsgify(RequestClass=Request)
-    def __call__(self, req):
-        """Call the method specified in req.environ by RoutesMiddleware."""
-        arg_dict = req.environ['wsgiorg.routing_args'][1]
-        action = arg_dict['action']
-        method = getattr(self, action)
-        LOG.debug("%s %s" % (req.method, req.url))
-        del arg_dict['controller']
-        del arg_dict['action']
-        if 'format' in arg_dict:
-            del arg_dict['format']
-        arg_dict['req'] = req
-        result = method(**arg_dict)
-
-        if type(result) is dict:
-            content_type = req.best_match_content_type()
-            default_xmlns = self.get_default_xmlns(req)
-            body = self._serialize(result, content_type, default_xmlns)
-
-            response = webob.Response()
-            response.headers['Content-Type'] = content_type
-            response.body = body
-            msg_dict = dict(url=req.url, status=response.status_int)
-            msg = _("%(url)s returned with HTTP %(status)d") % msg_dict
-            LOG.debug(msg)
-            return response
-        else:
-            return result
-
-    def _serialize(self, data, content_type, default_xmlns):
-        """Serialize the given dict to the provided content_type.
-
-        Uses self._serialization_metadata if it exists, which is a dict mapping
-        MIME types to information needed to serialize to that type.
-
-        """
-        _metadata = getattr(type(self), '_serialization_metadata', {})
-
-        serializer = Serializer(_metadata, default_xmlns)
-        try:
-            return serializer.serialize(data, content_type)
-        except exception.InvalidContentType:
-            raise webob.exc.HTTPNotAcceptable()
-
-    def _deserialize(self, data, content_type):
-        """Deserialize the request body to the specefied content type.
-
-        Uses self._serialization_metadata if it exists, which is a dict mapping
-        MIME types to information needed to serialize to that type.
-
-        """
-        _metadata = getattr(type(self), '_serialization_metadata', {})
-        serializer = Serializer(_metadata)
-        return serializer.deserialize(data, content_type)
-
-    def get_default_xmlns(self, req):
-        """Provide the XML namespace to use if none is otherwise specified."""
-        return None
-
-
-class Serializer(object):
-    """Serializes and deserializes dictionaries to certain MIME types."""
-
-    def __init__(self, metadata=None, default_xmlns=None):
-        """Create a serializer based on the given WSGI environment.
-
-        'metadata' is an optional dict mapping MIME types to information
-        needed to serialize a dictionary to that type.
-
-        """
-        self.metadata = metadata or {}
-        self.default_xmlns = default_xmlns
-
-    def _get_serialize_handler(self, content_type):
-        handlers = {
-            'application/json': self._to_json,
-            'application/xml': self._to_xml,
-        }
-
-        try:
-            return handlers[content_type]
-        except Exception:
-            raise exception.InvalidContentType(content_type=content_type)
-
-    def serialize(self, data, content_type):
-        """Serialize a dictionary into the specified content type."""
-        return self._get_serialize_handler(content_type)(data)
-
-    def deserialize(self, datastring, content_type):
-        """Deserialize a string to a dictionary.
-
-        The string must be in the format of a supported MIME type.
-
-        """
-        return self.get_deserialize_handler(content_type)(datastring)
-
-    def get_deserialize_handler(self, content_type):
-        handlers = {
-            'application/json': self._from_json,
-            'application/xml': self._from_xml,
-        }
-
-        try:
-            return handlers[content_type]
-        except Exception:
-            raise exception.InvalidContentType(content_type=content_type)
-
-    def _from_json(self, datastring):
-        return utils.loads(datastring)
-
-    def _from_xml(self, datastring):
-        xmldata = self.metadata.get('application/xml', {})
-        plurals = set(xmldata.get('plurals', {}))
-        node = minidom.parseString(datastring).childNodes[0]
-        return {node.nodeName: self._from_xml_node(node, plurals)}
-
-    def _from_xml_node(self, node, listnames):
-        """Convert a minidom node to a simple Python type.
-
-        listnames is a collection of names of XML nodes whose subnodes should
-        be considered list items.
-
-        """
-        if len(node.childNodes) == 1 and node.childNodes[0].nodeType == 3:
-            return node.childNodes[0].nodeValue
-        elif node.nodeName in listnames:
-            return [self._from_xml_node(n, listnames) for n in node.childNodes]
-        else:
-            result = dict()
-            for attr in node.attributes.keys():
-                result[attr] = node.attributes[attr].nodeValue
-            for child in node.childNodes:
-                if child.nodeType != node.TEXT_NODE:
-                    result[child.nodeName] = self._from_xml_node(child,
-                                                                 listnames)
-            return result
-
-    def _to_json(self, data):
-        return utils.dumps(data)
-
-    def _to_xml(self, data):
-        metadata = self.metadata.get('application/xml', {})
-        # We expect data to contain a single key which is the XML root.
-        root_key = data.keys()[0]
-        doc = minidom.Document()
-        node = self._to_xml_node(doc, metadata, root_key, data[root_key])
-
-        xmlns = node.getAttribute('xmlns')
-        if not xmlns and self.default_xmlns:
-            node.setAttribute('xmlns', self.default_xmlns)
-
-        return node.toprettyxml(indent='    ')
-
-    def _to_xml_node(self, doc, metadata, nodename, data):
-        """Recursive method to convert data members to XML nodes."""
-        result = doc.createElement(nodename)
-
-        # Set the xml namespace if one is specified
-        # TODO(justinsb): We could also use prefixes on the keys
-        xmlns = metadata.get('xmlns', None)
-        if xmlns:
-            result.setAttribute('xmlns', xmlns)
-
-        if type(data) is list:
-            collections = metadata.get('list_collections', {})
-            if nodename in collections:
-                metadata = collections[nodename]
-                for item in data:
-                    node = doc.createElement(metadata['item_name'])
-                    node.setAttribute(metadata['item_key'], str(item))
-                    result.appendChild(node)
-                return result
-            singular = metadata.get('plurals', {}).get(nodename, None)
-            if singular is None:
-                if nodename.endswith('s'):
-                    singular = nodename[:-1]
-                else:
-                    singular = 'item'
-            for item in data:
-                node = self._to_xml_node(doc, metadata, singular, item)
-                result.appendChild(node)
-        elif type(data) is dict:
-            collections = metadata.get('dict_collections', {})
-            if nodename in collections:
-                metadata = collections[nodename]
-                for k, v in data.items():
-                    node = doc.createElement(metadata['item_name'])
-                    node.setAttribute(metadata['item_key'], str(k))
-                    text = doc.createTextNode(str(v))
-                    node.appendChild(text)
-                    result.appendChild(node)
-                return result
-            attrs = metadata.get('attributes', {}).get(nodename, {})
-            for k, v in data.items():
-                if k in attrs:
-                    result.setAttribute(k, str(v))
-                else:
-                    node = self._to_xml_node(doc, metadata, k, v)
-                    result.appendChild(node)
-        else:
-            # Type is atom
-            node = doc.createTextNode(str(data))
-            result.appendChild(node)
-        return result
-
-
 def paste_config_file(basename):
     """Find the best location in the system for a paste config file.