src/mailman/model/uid.py

   1 # Copyright (C) 2011-2023 by the Free Software Foundation, Inc.
   2 #
   3 # This file is part of GNU Mailman.
   4 #
   5 # GNU Mailman is free software: you can redistribute it and/or modify it under
   6 # the terms of the GNU General Public License as published by the Free
   7 # Software Foundation, either version 3 of the License, or (at your option)
   8 # any later version.
   9 #
  10 # GNU Mailman is distributed in the hope that it will be useful, but WITHOUT
  11 # ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12 # FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13 # more details.
  14 #
  15 # You should have received a copy of the GNU General Public License along with
  16 # GNU Mailman.  If not, see <https://www.gnu.org/licenses/>.
  17
  18 """Unique IDs."""
  19
  20 from mailman.database.model import Model
  21 from mailman.database.transaction import dbconnection
  22 from mailman.database.types import UUID
  23 from public import public
  24 from sqlalchemy import Column, Integer
  25
  26
  27 @public
  28 class UID(Model):
  29     """Enforce uniqueness of uids through a database table.
  30
  31     This is used so that unique ids don't have to be tracked by each
  32     individual model object that uses them.  So for example, when a user is
  33     deleted, we don't have to keep separate track of its uid to prevent it
  34     from ever being used again.  This class, hooked up to the `UIDFactory`
  35     serves that purpose.
  36
  37     There is no interface for this class, because it's purely an internal
  38     implementation detail.
  39     """
  40
  41     __tablename__ = 'uid'
  42
  43     id = Column(Integer, primary_key=True)
  44     uid = Column(UUID, index=True)
  45
  46     @dbconnection
  47     def __init__(self, store, uid):
  48         super().__init__()
  49         self.uid = uid
  50         store.add(self)
  51
  52     def __repr__(self):
  53         return '<UID {} at {}>'.format(self.uid, id(self))
  54
  55     @staticmethod
  56     @dbconnection
  57     # Note that the parameter order is deliberately reversed here.  Normally,
  58     # `store` is the first parameter after `self`, but since this is a
  59     # staticmethod and there is no self, the decorator will see the uid in
  60     # arg[0].
  61     def record(uid, store):
  62         """Record the uid in the database.
  63
  64         :param uid: The unique id.
  65         :type uid: unicode
  66         :raises ValueError: if the id is not unique.
  67         """
  68         existing = store.query(UID).filter_by(uid=uid)
  69         if existing.count() != 0:
  70             raise ValueError(uid)
  71         return UID(uid)
  72
  73     @staticmethod
  74     @dbconnection
  75     def get_total_uid_count(store):
  76         return store.query(UID).count()
  77
  78     @staticmethod
  79     @dbconnection
  80     def cull_orphans(store):
  81         # Avoid circular imports.
  82         from mailman.model.user import User
  83
  84         # Delete all uids in this table that are not associated with user
  85         # rows.
  86         results = store.query(UID).filter(
  87             ~UID.uid.in_(store.query(User._user_id)))
  88         for uid in results.all():
  89             store.delete(uid)