[PATCH] REST: Fix duplicate project queries

[Mete Polat]

Eliminates duplicate project queries caused by calling
get_absolute_url() in the embedded serializers. Following foreign keys
with 'series__project' will cache the project of the series as well as
the series itself.

Signed-off-by: Mete Polat <metepolat2000 at gmail.com>
---
There are still some duplicates in various /api/ views but it looks like
those are caused by the REST framework itself.

 patchwork/api/cover.py  | 2 +-
 patchwork/api/event.py  | 4 ++--
 patchwork/api/patch.py  | 2 +-
 patchwork/api/series.py | 5 +++--
 4 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/patchwork/api/cover.py b/patchwork/api/cover.py
index caf9a386efa5..9e86d47e00e5 100644
--- a/patchwork/api/cover.py
+++ b/patchwork/api/cover.py
@@ -101,7 +101,7 @@ class CoverLetterList(ListAPIView):
 
     def get_queryset(self):
         return CoverLetter.objects.all()\
-            .select_related('project', 'submitter', 'series')\
+            .select_related('project', 'submitter', 'series__project')\
             .defer('content', 'headers')
 
 
diff --git a/patchwork/api/event.py b/patchwork/api/event.py
index a066faaec63b..fdff6a4f2fa6 100644
--- a/patchwork/api/event.py
+++ b/patchwork/api/event.py
@@ -86,7 +86,7 @@ class EventList(ListAPIView):
 
     def get_queryset(self):
         return Event.objects.all()\
-            .prefetch_related('project', 'patch', 'series', 'cover',
-                              'previous_state', 'current_state',
+            .prefetch_related('project', 'patch__project', 'series__project',
+                              'cover', 'previous_state', 'current_state',
                               'previous_delegate', 'current_delegate',
                               'created_check')
diff --git a/patchwork/api/patch.py b/patchwork/api/patch.py
index a29a1ab0eb71..1a3ce9057490 100644
--- a/patchwork/api/patch.py
+++ b/patchwork/api/patch.py
@@ -176,7 +176,7 @@ class PatchList(ListAPIView):
         return Patch.objects.all()\
             .prefetch_related('check_set')\
             .select_related('project', 'state', 'submitter', 'delegate',
-                            'series')\
+                            'series__project')\
             .defer('content', 'diff', 'headers')
 
 
diff --git a/patchwork/api/series.py b/patchwork/api/series.py
index f7bb8c06a6c9..df28f95dab1b 100644
--- a/patchwork/api/series.py
+++ b/patchwork/api/series.py
@@ -55,8 +55,9 @@ class SeriesMixin(object):
     serializer_class = SeriesSerializer
 
     def get_queryset(self):
-        return Series.objects.all().prefetch_related('patches',)\
-            .select_related('submitter', 'cover_letter', 'project')
+        return Series.objects.all()\
+            .prefetch_related('patches__project',)\
+            .select_related('submitter', 'cover_letter__project', 'project')
 
 
 class SeriesList(SeriesMixin, ListAPIView):
-- 
2.25.0