Make chat faster

chat_box/models.py

@@ -1,6 +1,7 @@
 from django.db import models
 from django.db.models import CASCADE, Q
 from django.utils.translation import gettext_lazy as _
+from django.utils.functional import cached_property
 
 
 from judge.models.profile import Profile
@@ -17,25 +18,39 @@ class Room(models.Model):
     user_two = models.ForeignKey(
         Profile, related_name="user_two", verbose_name="user 2", on_delete=CASCADE
     )
+    last_msg_time = models.DateTimeField(
+        verbose_name=_("last seen"), null=True, db_index=True
+    )
 
     class Meta:
         app_label = "chat_box"
 
-    @cache_wrapper(prefix="Rc")
-    def contain(self, profile):
-        return self.user_one == profile or self.user_two == profile
+    @cache_wrapper(prefix="Rinfo")
+    def _info(self):
+        return {
+            "user_ids": [self.user_one.id, self.user_two.id],
+            "last_message": self.message_set.first().body,
+        }
+
+    @cached_property
+    def _cached_info(self):
+        return self._info()
+
+    def contain(self, profile):
+        return profile.id in self._cached_info["user_ids"]
 
-    @cache_wrapper(prefix="Rou")
     def other_user(self, profile):
         return self.user_one if profile == self.user_two else self.user_two
 
-    @cache_wrapper(prefix="Rus")
+    def other_user_id(self, profile):
+        user_ids = self._cached_info["user_ids"]
+        return sum(user_ids) - profile.id
+
     def users(self):
         return [self.user_one, self.user_two]
 
-    @cache_wrapper(prefix="Rlmb")
     def last_message_body(self):
-        return self.message_set.first().body
+        return self._cached_info["last_message"]
 
 
 class Message(models.Model):