add a faster MP3.get_many() method

server/djrandom/frontend/views.py

@@ -42,7 +42,7 @@ def autocomplete_search():
 def songs_fragment():
     hashes = request.form.get('h', '')
     if hashes:
-        mp3s = [MP3.query.get(h) for h in hashes.split(',')]
+        mp3s = MP3.get_many(hashes.split(','))
     else:
         mp3s = []
     return render_template('songs_fragment.html', songs=mp3s)

server/djrandom/model/mp3.py

@@ -69,6 +69,12 @@ class MP3(Base):
             data['track_num'] = self.track_num
         return data
 
+    @classmethod
+    def get_many(cls, hashes):
+        order = dict((sha1, idx) for idx, sha1 in enumerate(hashes))
+        mp3s = cls.query.filter(cls.sha1.in_(hashes))
+        return sorted(mp3s, key=lambda x: order[x.sha1])
+
     def mark_as_duplicate(self, duplicate_of):
         self.state = self.DUPLICATE
         self.duplicate_of = duplicate_of

server/djrandom/test/test_model.py

@@ -75,6 +75,17 @@ class MP3Test(DbTestCase):
         result_ids = set(x.sha1 for x in results)
         self.assertEquals(set(['1001', '1002']), result_ids)
 
+    def test_mp3_get_many(self):
+        for i in range(1, 4):
+            mp3, _ = create_mp3(unicode(i))
+            Session.add(mp3)
+        Session.commit()
+
+        hashes = [u'3', u'1', u'2']
+        results = MP3.get_many(hashes)
+        result_hashes = [x.sha1 for x in results]
+        self.assertEquals(hashes, result_hashes)
+
     def test_mp3_get_with_bad_metadata(self):
         pass