[Enhance] Add limiter & Building API

- Add a custom limiter and use it for limiting users' download instead of using database
> So add a requirement `limits`.

- Fix a character's value
- Change the email max length to 64
- Change something about API's roles and powers
- Add an API endpoint for getting users' roles and powers

latest version/core/api_user.py

@@ -9,50 +9,40 @@ from .user import UserOnline
 class Power:
     def __init__(self, c=None):
         self.c = c
-        self.power_id: int = None
-        self.power_name: str = None
+        self.power_id: str = None
         self.caption: str = None
 
     @classmethod
     def from_dict(cls, d: dict, c=None) -> 'Power':
         p = cls(c)
         p.power_id = d['power_id']
-        p.power_name = d['power_name']
         p.caption = d['caption']
         return p
 
-    def select_from_name(self, power_name: str) -> 'Power':
-        pass
-
 
 class Role:
     def __init__(self, c=None):
         self.c = c
-        self.role_id: int = None
-        self.role_name: str = None
+        self.role_id: str = None
         self.caption: str = None
 
         self.powers: list = None
 
-    def has_power(self, power_name: str) -> bool:
+    def has_power(self, power_id: str) -> bool:
         '''判断role是否有power'''
-        for i in self.powers:
-            if i.power_name == power_name:
-                return True
-        return False
+        return any(power_id == i.power_id for i in self.powers)
 
     def select_from_id(self, role_id: int = None) -> 'Role':
         '''用role_id查询role'''
         if role_id is not None:
             self.role_id = role_id
-        self.c.execute('''select role_name, caption from role where role_id = :a''',
+        self.c.execute('''select caption from role where role_id = :a''',
                        {'a': self.role_id})
         x = self.c.fetchone()
         if x is None:
             raise NoData('The role `%s` does not exist.' %
                          self.role_id, api_error_code=-200)
-        self.role_name = x[0]
-        self.caption = x[1]
+        self.caption = x[0]
         return self
 
     def select_powers(self) -> None:
@@ -63,7 +53,7 @@ class Role:
         x = self.c.fetchall()
         for i in x:
             self.powers.append(Power.from_dict(
-                {'power_id': i[0], 'power_name': i[1], 'caption': i[2]}, self.c))
+                {'power_id': i[0], 'caption': i[1]}, self.c))
 
 
 class APIUser(UserOnline):
@@ -74,6 +64,13 @@ class APIUser(UserOnline):
 
         self.ip: str = None
 
+    def set_role_system(self) -> None:
+        '''设置为最高权限用户，API接口'''
+        self.user_id = 0
+        self.role = Role(self.c)
+        self.role.role_id = 'system'
+        self.role.select_powers()
+
     def select_role(self) -> None:
         '''查询user的role'''
         self.c.execute('''select role_id from user_role where user_id = :a''',
@@ -82,10 +79,9 @@ class APIUser(UserOnline):
         self.role = Role(self.c)
         if x is None:
             # 默认role为user
-            self.role.role_id = 1
+            self.role.role_id = 'user'
         else:
-            self.role.role_id = int(x[0])
-        self.role.select_from_id()
+            self.role.role_id = x[0]
 
     def select_role_and_powers(self) -> None:
         '''查询user的role，以及role的powers'''