Support for markers for pagination as defined in the 1.1 spec.

3 files changed, 42 insertions, 1 deletions

diff --git a/nova/api/openstack/common.py b/nova/api/openstack/common.py
index b224cbfb4..8106f841b 100644
--- a/nova/api/openstack/common.py
+++ b/nova/api/openstack/common.py
@@ -55,6 +55,34 @@ def limited(items, request, max_limit=1000):
     return items[offset:range_end]
 
 
+def limited_by_marker(items, request, max_limit=1000):
+    ''' Return a slice of items according to requested marker and limit. '''
+
+    marker = request.GET.get('marker')
+
+    try:
+        limit = int(request.GET.get('limit', max_limit))
+    except ValueError:
+        raise webob.exc.HTTPBadRequest(_('limit param must be an integer'))
+
+    if limit < 0:
+        raise webob.exc.HTTPBadRequest(_('limit param must be positive'))
+
+    limit = min(max_limit, limit or max_limit)
+    start_index = 0
+    if marker != None:
+        found_it = False
+        for i, item in enumerate(items):
+            if str(item['id']) == marker:
+                start_index = i
+                found_it = True
+                break
+        if not found_it:
+            raise webob.exc.HTTPBadRequest(_('marker not found'))
+    range_end = start_index + limit
+    return items[start_index:range_end]
+
+
 def get_image_id_from_image_hash(image_service, context, image_hash):
     """Given an Image ID Hash, return an objectstore Image ID.
 
diff --git a/nova/api/openstack/servers.py b/nova/api/openstack/servers.py
index e3141934b..461bf5989 100644
--- a/nova/api/openstack/servers.py
+++ b/nova/api/openstack/servers.py
@@ -81,7 +81,7 @@ class Controller(wsgi.Controller):
         builder - the response model builder
         """
         instance_list = self.compute_api.get_all(req.environ['nova.context'])
-        limited_list = common.limited(instance_list, req)
+        limited_list = self._limit_items(instance_list, req)
         builder = self._get_view_builder(req)
         servers = [builder.build(inst, is_detail)['server']
                 for inst in limited_list]
@@ -528,6 +528,9 @@ class ControllerV10(Controller):
     def _get_addresses_view_builder(self, req):
         return nova.api.openstack.views.addresses.ViewBuilderV10(req)
 
+    def _limit_items(self, items, req):
+        return common.limited(items, req)
+
 
 class ControllerV11(Controller):
     def _image_id_from_req_data(self, data):
@@ -551,6 +554,9 @@ class ControllerV11(Controller):
     def _get_addresses_view_builder(self, req):
         return nova.api.openstack.views.addresses.ViewBuilderV11(req)
 
+    def _limit_items(self, items, req):
+        return common.limited_by_marker(items, req)
+
 
 class ServerCreateRequestXMLDeserializer(object):
     """
diff --git a/nova/tests/api/openstack/test_servers.py b/nova/tests/api/openstack/test_servers.py
index 6e78db9da..e1cadcef6 100644
--- a/nova/tests/api/openstack/test_servers.py
+++ b/nova/tests/api/openstack/test_servers.py
@@ -239,6 +239,13 @@ class ServersTest(test.TestCase):
         servers = json.loads(res.body)['servers']
         self.assertEqual([s['id'] for s in servers], [1, 2])
 
+    def test_get_servers_with_marker(self):
+        req = webob.Request.blank('/v1.1/servers?marker=2')
+        res = req.get_response(fakes.wsgi_app())
+        print 'body:', res.body
+        servers = json.loads(res.body)['servers']
+        self.assertEqual([s['id'] for s in servers], [2, 3, 4])
+
     def _setup_for_create_instance(self):
         """Shared implementation for tests below that create instance"""
         def instance_create(context, inst):