Make chat faster

chat_box/migrations/0015_room_last_msg_time.py

@@ -0,0 +1,33 @@
+# Generated by Django 3.2.18 on 2023-11-02 01:41
+
+from django.db import migrations, models
+
+
+def migrate(apps, schema_editor):
+    Room = apps.get_model("chat_box", "Room")
+    Message = apps.get_model("chat_box", "Message")
+
+    for room in Room.objects.all():
+        messages = room.message_set
+        last_msg = messages.first()
+        if last_msg:
+            room.last_msg_time = last_msg.time
+            room.save()
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("chat_box", "0014_userroom_unread_count"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="room",
+            name="last_msg_time",
+            field=models.DateTimeField(
+                db_index=True, null=True, verbose_name="last seen"
+            ),
+        ),
+        migrations.RunPython(migrate, migrations.RunPython.noop, atomic=True),
+    ]

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):

chat_box/views.py

@@ -84,8 +84,8 @@ class ChatView(ListView):
         self.room_id = request_room
         self.messages = (
             Message.objects.filter(hidden=False, room=self.room_id, id__lt=last_id)
-            .select_related("author", "author__user")
-            .defer("author__about", "author__user_script")[:page_size]
+            .select_related("author")
+            .only("body", "time", "author__rating", "author__display_rank")[:page_size]
         )
         if not only_messages:
             return super().get(request, *args, **kwargs)
@@ -204,7 +204,9 @@ def post_message(request):
             },
         )
     else:
-        Room.last_message_body.dirty(room)
+        Room._info.dirty(room)
+        room.last_msg_time = new_message.time
+        room.save()
 
         for user in room.users():
             event.post(
@@ -351,11 +353,11 @@ def get_online_status(profile, other_profile_ids, rooms=None):
             room = Room.objects.get(id=i["room"])
             other_profile = room.other_user(profile)
             count[other_profile.id] = i["unread_count"]
+        rooms = Room.objects.filter(id__in=rooms)
         for room in rooms:
-            room = Room.objects.get(id=room)
-            other_profile = room.other_user(profile)
-            last_msg[other_profile.id] = room.last_message_body()
-            room_of_user[other_profile.id] = room.id
+            other_profile_id = room.other_user_id(profile)
+            last_msg[other_profile_id] = room.last_message_body()
+            room_of_user[other_profile_id] = room.id
 
     for other_profile in other_profiles:
         is_online = False
@@ -389,9 +391,6 @@ def get_status_context(profile, include_ignored=False):
     recent_profile = (
         Room.objects.filter(Q(user_one=profile) | Q(user_two=profile))
         .annotate(
-            last_msg_time=Subquery(
-                Message.objects.filter(room=OuterRef("pk")).values("time")[:1]
-            ),
             other_user=Case(
                 When(user_one=profile, then="user_two"),
                 default="user_one",
@@ -412,28 +411,15 @@ def get_status_context(profile, include_ignored=False):
         .values_list("id", flat=True)
     )
 
-    all_user_status = (
-        queryset.filter(last_access__gte=last_5_minutes)
-        .annotate(is_online=Case(default=True, output_field=BooleanField()))
-        .order_by("-rating")
-        .exclude(id__in=admin_list)
-        .exclude(id__in=recent_profile_ids)
-        .values_list("id", flat=True)[:30]
-    )
-
     return [
         {
-            "title": "Recent",
+            "title": _("Recent"),
             "user_list": get_online_status(profile, recent_profile_ids, recent_rooms),
         },
         {
-            "title": "Admin",
+            "title": _("Admin"),
             "user_list": get_online_status(profile, admin_list),
         },
-        {
-            "title": "Other",
-            "user_list": get_online_status(profile, all_user_status),
-        },
     ]