optimize GET assets/ to reduce queries and improve speed dramatically…

… on large data sets

roundware/api2/serializers.py

@@ -61,7 +61,7 @@ class Meta:
             'tags',
             'session',
             'project',
-            'envelope_set'
+            'envelope'
         )
         localized_fields = ['loc_description', 'loc_alt_text']
 
@@ -86,8 +86,8 @@ def to_representation(self, obj):
         result["language_id"] = result["language"]
         del result["language"]
 
-        result["envelope_ids"] = result["envelope_set"]
-        del result["envelope_set"]
+        result["envelope_ids"] = result["envelope"]
+        del result["envelope"]
 
         result["description_loc_ids"] = result["loc_description"]
         del result["loc_description"]

roundware/api2/views.py

@@ -36,6 +36,10 @@
 from datetime import datetime
 from distutils.util import strtobool
 from collections import OrderedDict
+try:
+    from profiling import profile
+except ImportError: # pragma: no cover
+    pass
 
 logger = logging.getLogger(__name__)
 
@@ -90,14 +94,16 @@ class AssetViewSet(viewsets.GenericViewSet, AssetPaginationMixin,):
     """
 
     # TODO: Implement DjangoObjectPermissions
-    queryset = Asset.objects.all()
+    queryset = Asset.objects.prefetch_related('tags', 'loc_description', 'loc_alt_text', 'envelope') \
+                            .select_related('session', 'project', 'language', 'initialenvelope').all()
     permission_classes = (IsAuthenticated,)
     pagination_class = AssetPagination
     serializer_class = serializers.AssetSerializer
     filter_backends = (DjangoFilterBackend, OrderingFilter,)
     ordering_fields = ('id', 'session_id', 'audiolength', 'weight', 'volume')
     filter_class = AssetFilterSet
 
+    # @profile(stats=True)
     def list(self, request):
         """
         GET api/2/assets/ - retrieve list of Assets filtered by parameters

roundware/rw/migrations/0029_envelope_related_name.py

@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.9 on 2018-04-18 17:10
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('rw', '0028_add_uielement_models'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='envelope',
+            name='assets',
+            field=models.ManyToManyField(blank=True, related_name='envelope', to='rw.Asset'),
+        ),
+    ]

roundware/rw/models.py

@@ -290,7 +290,7 @@ class Envelope(models.Model):
     """
     session = models.ForeignKey('Session', blank=True)
     created = models.DateTimeField(default=datetime.now)
-    assets = models.ManyToManyField(Asset, blank=True)
+    assets = models.ManyToManyField(Asset, blank=True, related_name='envelope')
 
     def __unicode__(self):
         return str(self.id) + ": Session id: " + str(self.session.id)