Move global user cache to a WeakValueDictionary.

discord/client.py

@@ -507,14 +507,26 @@ class Client:
 
     # helpers/getters
 
+    @property
+    def users(self):
+        """Returns a list of all the :class:`User` the bot can see."""
+        return list(self.connection._users.values())
+
     def get_channel(self, id):
-        """Returns a :class:`Channel` or :class:`PrivateChannel` with the following ID. If not found, returns None."""
+        """Returns a :class:`abc.GuildChannel` or :class:`abc.PrivateChannel` with the following ID.
+
+        If not found, returns None.
+        """
         return self.connection.get_channel(id)
 
     def get_guild(self, id):
         """Returns a :class:`Guild` with the given ID. If not found, returns None."""
         return self.connection._get_guild(id)
 
+    def get_user(self, id):
+        """Returns a :class:`User` with the given ID. If not found, returns None."""
+        return self.connection.get_user(id)
+
     def get_all_emojis(self):
         """Returns a generator with every :class:`Emoji` the client can see."""
         for guild in self.guilds:

discord/state.py

@@ -42,6 +42,7 @@ import copy, enum, math
 import datetime
 import asyncio
 import logging
+import weakref
 
 class ListenerType(enum.Enum):
     chunk = 0
@@ -66,8 +67,8 @@ class ConnectionState:
         self.user = None
         self.sequence = None
         self.session_id = None
+        self._users = weakref.WeakValueDictionary()
         self._calls = {}
-        self._users = {}
         self._emojis = {}
         self._guilds = {}
         self._voice_clients = {}
@@ -133,6 +134,9 @@ class ConnectionState:
             self._users[user_id] = user = User(state=self, data=data)
             return user
 
+    def get_user(self, id):
+        return self._users.get(id)
+
     def store_emoji(self, guild, data):
         emoji_id = int(data['id'])
         try:

discord/user.py

@@ -61,7 +61,7 @@ class User(discord.abc.Messageable):
         Specifies if the user is a bot account.
     """
 
-    __slots__ = ('name', 'id', 'discriminator', 'avatar', 'bot', '_state')
+    __slots__ = ('name', 'id', 'discriminator', 'avatar', 'bot', '_state', '__weakref__')
 
     def __init__(self, *, state, data):
         self._state = state