Combine {Item,Clip,edit.Clip}.get_layers()

This has several benefits:

    • Clip.get_layers() (used by smart edits) and Item.get_layers() pick up
    the select_related('user') optimization added for static edits in
    r5007.

    • Static edits and items pick up the optimization from r4941 to select
    annotations once, not once per layer.

Fetching an item with ~1000 annotations took ~1s without this patch,
~0.34s with this patch. Another item with ~6000 annotations took ~11.6s
before, ~8.6s after.

Because this block is moved out to the top:

if user and user.is_anonymous():
user = None

then, for anonymous users,

"editable": false,

is no longer included in the annotations. The old behaviour ended up
including this key in all layers listed before the first private layer
in the config, and leaving it out from later ones. So this new behaviour
is more consistent.

pandora/clip/models.py

@@ -11,6 +11,36 @@ from archive import extract
 import managers
 
 
+def get_layers(item, interval=None, user=None):
+    from annotation.models import Annotation
+
+    if user and user.is_anonymous():
+        user = None
+
+    layers = {}
+    private = []
+    for l in settings.CONFIG['layers']:
+        name = l['id']
+        layers[name] = []
+        if l.get('private'):
+            private.append(name)
+
+    qs = Annotation.objects.filter(item=item).exclude(value='')
+    qs = qs.order_by('start', 'end', 'sortvalue')
+
+    if interval:
+        start, end = interval
+        qs = qs.filter(start__lt=end, end__gt=start)
+
+    for a in qs.order_by('start').select_related('user'):
+        if a.layer in private:
+            if a.user == user:
+                layers[a.layer].append(a.json(user=user))
+        else:
+            layers[a.layer].append(a.json(user=user))
+    return layers
+
+
 class MetaClip:
     def update_calculated_values(self):
         start = self.start
@@ -113,27 +143,7 @@ class MetaClip:
         return data
 
     def get_layers(self, user=None):
-        from annotation.models import Annotation
-        start = self.start
-        end = self.end
-        item = self.item
-        layers = {}
-        private = []
-        for l in settings.CONFIG['layers']:
-            name = l['id']
-            layers[name] = []
-            if l.get('private'):
-                private.append(name)
-        qs = Annotation.objects.filter(item=item).exclude(value='')
-        qs = qs.order_by('start', 'end', 'sortvalue')
-        qs = qs.filter(start__lt=end, end__gt=start)
-        for a in qs.order_by('start'):
-            if a.layer in private:
-                if a.user == user:
-                    layers[a.layer].append(a.json(user=user))
-            else:
-                layers[a.layer].append(a.json(user=user))
-        return layers
+        return get_layers(item=self.item, interval=(self.start, self.end), user=user)
 
     @classmethod
     def get_or_create(cls, item, start, end):

pandora/edit/models.py

@@ -511,22 +511,8 @@ class Clip(models.Model):
             start = self.start
             end = self.end
             item = self.item
-        layers = {}
-        for l in settings.CONFIG['layers']:
-            name = l['id']
-            ll = layers.setdefault(name, [])
-            qs = Annotation.objects.filter(layer=name, item=item).order_by(
-                    'start', 'end', 'sortvalue')
-            if name == 'subtitles':
-                qs = qs.exclude(value='')
-            qs = qs.filter(start__lt=end, end__gt=start)
-            if l.get('private'):
-                if user and user.is_anonymous():
-                    user = None
-                qs = qs.filter(user=user)
-            for a in qs.order_by('start').select_related('user'):
-                ll.append(a.json(user=user))
-        return layers
+
+        return clip.models.get_layers(item=item, interval=(start, end), user=user)
 
 class Position(models.Model):
 

pandora/item/models.py

@@ -34,7 +34,7 @@ from data_api import external_data
 
 from annotation.models import Annotation
 from archive import extract
-from clip.models import Clip
+from clip.models import Clip, get_layers
 from person.models import get_name_sort
 from sequence.tasks import get_sequences
 from title.models import get_title_sort
@@ -547,21 +547,8 @@ class Item(models.Model):
             return s.json()
 
     def get_layers(self, user=None):
-        layers = {}
-        for l in settings.CONFIG['layers']:
-            name = l['id']
-            ll = layers.setdefault(name, [])
-            qs = Annotation.objects.filter(layer=name, item=self).order_by(
-                    'start', 'end', 'sortvalue')
-            qs = qs.exclude(value='')
-            if l.get('private'):
-                if user and user.is_anonymous():
-                    user = None
-                qs = qs.filter(user=user)
-            for a in qs.order_by('start'):
-                ll.append(a.json(user=user))
-        return layers
-    
+        return get_layers(item=self, user=user)
+
     def get_documents(self, user=None):
         qs = self.documents.all()
         documents = [d.json(item=self) for d in qs]