perf(assets): 优化节点树

修改树策略，做读优化，写的速度降低

apps/perms/serializers/user_permission.py

@@ -82,8 +82,6 @@ class AssetGrantedSerializer(serializers.ModelSerializer):
 
 
 class NodeGrantedSerializer(serializers.ModelSerializer):
-    assets_amount = serializers.SerializerMethodField()
-
     class Meta:
         model = Node
         fields = [
@@ -91,15 +89,6 @@ class NodeGrantedSerializer(serializers.ModelSerializer):
         ]
         read_only_fields = fields
 
-    def __init__(self, *args, **kwargs):
-        super().__init__(*args, **kwargs)
-        self.tree = self.context.get("tree")
-
-    def get_assets_amount(self, obj):
-        if not self.tree:
-            return 0
-        return self.tree.assets_amount(obj.key)
-
 
 class ActionsSerializer(serializers.Serializer):
     actions = ActionsField(read_only=True)