random clip sort

pandora/clip/models.py

@@ -115,7 +115,6 @@ attrs = {
     'aspect_ratio': models.FloatField(default=0),
 
     'item': models.ForeignKey('item.Item', related_name='clips'),
-    'random': models.BigIntegerField(default=0, db_index=True, null=True),
 
     #seconds
     'start': models.FloatField(default=-1, db_index=True),
@@ -139,3 +138,7 @@ for name in settings.CONFIG['clipLayers']:
 
 Clip = type('Clip', (MetaClip,models.Model), attrs)
 
+class Random(models.Model):
+    clip = models.ForeignKey(Clip, primary_key=True)
+    random = models.BigIntegerField(db_index=True, null=True)
+

pandora/clip/views.py

@@ -42,7 +42,7 @@ def order_query(qs, sort):
         clip_keys = ('public_id', 'start', 'end', 'hue', 'saturation', 'lightness', 'volume',
                      'duration', 'sortvalue', 'videoRatio',
                      'director', 'title',
-                     'random')
+                     'random__random')
         key = {
             'id': 'public_id',
             'in': 'start',
@@ -50,6 +50,7 @@ def order_query(qs, sort):
             'position': 'start',
             'text': 'sortvalue',
             'videoRatio': 'aspect_ratio',
+            'random': 'random__random',
         }.get(e['key'], e['key'])
         if key.startswith('clip:'):
             key = e['key'][len('clip:'):]

pandora/item/tasks.py

@@ -29,14 +29,14 @@ def update_random_sort():
 
 def update_random_clip_sort():
     if filter(lambda f: f['id'] == 'random', settings.CONFIG['itemKeys']):
-        random.seed()
-        from clip.models import Clip
-        ids = [f['id'] for f in Clip.objects.values('id')]
-        random.shuffle(ids)
-        n = 1
-        for i in ids:
-            Clip.objects.filter(pk=i).update(random=n)
-            n += 1
+        from django.db import connection, transaction
+        cursor = connection.cursor()
+        cursor.execute('DROP TABLE clip_random;')
+        cursor.execute('CREATE TABLE "clip_random" AS SELECT id AS clip_id, row_number() OVER (ORDER BY random()) AS random FROM "clip_clip"')
+        cursor.execute('ALTER TABLE "clip_random" ADD UNIQUE ("clip_id")')
+        cursor.execute('CREATE INDEX "clip_random_clip_id_idx" ON "clip_random" ("clip_id")')
+        cursor.execute('CREATE INDEX "clip_random_random_idx" ON "clip_random" ("random")')
+        transaction.commit_unless_managed()
 
 @task(ignore_results=True, queue='default')
 def update_poster(itemId):