try to get preview from peers, fixes #79

oml/item/icons.py

@@ -93,14 +93,12 @@ class Icons(dict):
 
 icons = Icons(icons_db_path)
 
-@run_async
-def get_icon(id, type_, size, callback):
+def get_icon_sync(id, type_, size):
     if size:
         skey = '%s:%s:%s' % (type_, id, size)
         data = icons[skey]
         if data:
-            callback(bytes(data))
-            return
+            return bytes(data)
     key = '%s:%s' % (type_, id)
     data = icons[key]
     if not data:
@@ -128,7 +126,11 @@ def get_icon(id, type_, size, callback):
     if size:
         data = icons[skey] = resize_image(data, size=size)
     data = bytes(data) or ''
-    callback(data)
+    return data
+
+@run_async
+def get_icon(id, type_, size, callback):
+    callback(get_icon_sync(id, type_, size))
 
 def clear_default_cover_cache():
     icons.clear('default:cover:')

oml/item/models.py

@@ -366,6 +366,11 @@ class Item(db.Model):
         path = self.get_path()
         if path:
             return getattr(media, self.info['extension']).cover(path)
+        else:
+            for u in self.users:
+                if u.id != settings.USER_ID:
+                    if state.nodes.download_preview(u.id, self.id):
+                        break
 
     def update_cover(self):
         key = 'cover:%s'%self.id
@@ -388,6 +393,14 @@ class Item(db.Model):
                 del self.info['coverRatio']
         icons.clear('cover:%s:' % self.id)
 
+    def get_preview(self):
+        key = 'preview:%s'%self.id
+        data = icons[key]
+        if not data:
+            preview = self.extract_preview()
+            if preview:
+                icons[key] = preview
+
     def update_preview(self):
         key = 'preview:%s'%self.id
         preview = self.extract_preview()