Add request bound data, shared with subrequests.

This allows to store any arbitrary data in a ``dict`` on the current request,
instead of setting custom attributes and testing their existance.

It is shared with subrequests during batch.

In the short term, this will allow us to reduce storage hits in batch
subrequests on the default bucket in Kinto.

In the long term, this will allow us to share storage connections accross
batch subrequests.

cliquet/__init__.py

@@ -40,6 +40,7 @@
     'cliquet.http_scheme': None,
     'cliquet.id_generator': 'cliquet.storage.generators.UUID4',
     'cliquet.initialization_sequence': (
+        'cliquet.initialization.setup_request_bound_data',
         'cliquet.initialization.setup_json_serializer',
         'cliquet.initialization.setup_logging',
         'cliquet.initialization.setup_storage',

cliquet/initialization.py

@@ -31,6 +31,16 @@
 from pyramid_multiauth import MultiAuthPolicySelected
 
 
+def setup_request_bound_data(config):
+    """Attach custom data on request object, and share it with parent
+    requests during batch."""
+    def attach_bound_data(request):
+        parent = getattr(request, 'parent', None)
+        return parent.bound_data if parent else {}
+
+    config.add_request_method(attach_bound_data, name='bound_data', reify=True)
+
+
 def setup_json_serializer(config):
     # Monkey patch to use ujson
     webob.request.json = utils.json

cliquet/tests/test_initialization.py

@@ -2,6 +2,7 @@
 import webtest
 
 from pyramid.config import Configurator
+from pyramid.events import NewRequest
 
 import cliquet
 from cliquet import initialization
@@ -245,6 +246,33 @@ def _get_app(self, settings={}):
         cliquet.initialize(config, '0.0.1', 'name')
         return webtest.TestApp(config.make_wsgi_app())
 
+    def test_requests_have_a_bound_data_attribute(self):
+        config = Configurator()
+        cliquet.initialize(config, '0.0.1', 'name')
+
+        def on_new_request(event):
+            data = event.request.bound_data
+            self.assertEqual(data, {})
+            self.assertEqual(id(data), id(event.request.bound_data))
+
+        config.add_subscriber(on_new_request, NewRequest)
+        app = webtest.TestApp(config.make_wsgi_app())
+        app.get('/v0/')
+
+    def test_subrequests_share_parent_bound_data(self):
+        config = Configurator()
+        cliquet.initialize(config, '0.0.1', 'name')
+
+        bound_datas = set()
+
+        def on_new_request(event):
+            bound_datas.add(id(event.request.bound_data))
+
+        config.add_subscriber(on_new_request, NewRequest)
+        app = webtest.TestApp(config.make_wsgi_app())
+        app.post_json('/v0/batch', {'requests': [{'path': '/'}]})
+        self.assertEqual(len(bound_datas), 1)
+
     def test_by_default_relies_on_pyramid_application_url(self):
         app = self._get_app()
         resp = app.get('/v0/')

cliquet/tests/test_views_batch.py

@@ -253,6 +253,12 @@ def test_returns_requests_path_in_responses(self):
         result = self.post({'requests': [{'path': '/'}]})
         self.assertEqual(result['responses'][0]['path'], '/v0/')
 
+    def test_subrequests_have_parent_attribute(self):
+        self.request.path = '/batch'
+        self.post({'requests': [{'path': '/'}]})
+        subrequest, = self.request.invoke_subrequest.call_args[0]
+        self.assertEqual(subrequest.parent.path, '/batch')
+
     def test_subrequests_are_GET_by_default(self):
         self.post({'requests': [{'path': '/'}]})
         subrequest, = self.request.invoke_subrequest.call_args[0]

cliquet/views/batch.py

@@ -91,6 +91,7 @@ def post_batch(request):
 
     for subrequest_spec in requests:
         subrequest = build_request(request, subrequest_spec)
+        subrequest.parent = request
 
         sublogger.bind(path=subrequest.path,
                        method=subrequest.method)