[fix] パーミッションが無限に増える仕様を変更

mitama/permission.py

@@ -3,6 +3,7 @@
 from mitama.nodes import User, Group, Relation
 from mitama.db.types import Column, Integer, Node
 from sqlalchemy.ext.declarative import declared_attr
+from sqlalchemy.schema import UniqueConstraint
 
 class PermissionMixin(object):
     '''パーミッションのモデルの実装を支援します
@@ -34,6 +35,13 @@ class SomePermission(PermissionMixin, db.Model):
     @declared_attr
     def __tablename__(cls):
         return '__'+cls.__name__.lower()+'_permission'
+    @declared_attr
+    def __table_args__(cls):
+        if hasattr(cls, 'target'):
+            unique = UniqueConstraint('node', 'target', name='unique')
+        else:
+            unique = UniqueConstraint('node', name='unique')
+        return (unique, )
     node = Column(Node)
     targetUpPropagate = False
     targetDownPropagate = False
@@ -71,10 +79,7 @@ def is_accepted(cls, node, target = None):
         :param node: UserまたはGroupのインスタンス
         :param target: 許可対象
         '''
-        query = cls.query.filter(cls.node == node)
-        if hasattr(cls, 'target'):
-            query = query.filter(cls.target == target)
-        perms = query.all()
+        perms = cls.query.filter(cls.node == node).all()
         for perm in perms:
             if perm.is_target(target) or perm.is_target(None):
                 return True