From b848d321f91fa3b445f4c5ee6a0f4b753c74af27 Mon Sep 17 00:00:00 2001
From: Johnny <strikaco@users.noreply.github.com>
Date: Tue, 14 Jan 2020 22:05:02 +0000
Subject: [PATCH] Refactors object_totals to crunch more of the data db-side
 instead of app-side.

---
 evennia/commands/default/system.py |  6 ++---
 evennia/typeclasses/managers.py    | 38 ++++++++++++++++++++++--------
 2 files changed, 31 insertions(+), 13 deletions(-)

diff --git a/evennia/commands/default/system.py b/evennia/commands/default/system.py
index 9084117ea0..00125388c7 100644
--- a/evennia/commands/default/system.py
+++ b/evennia/commands/default/system.py
@@ -606,9 +606,9 @@ class CmdObjects(COMMAND_DEFAULT_CLASS):
             "|wtypeclass|n", "|wcount|n", "|w%|n", border="table", align="l"
         )
         typetable.align = "l"
-        dbtotals = ObjectDB.objects.object_totals()
-        for path, count in dbtotals.items():
-            typetable.add_row(path, count, "%.2f" % ((float(count) / nobjs) * 100))
+        dbtotals = ObjectDB.objects.get_typeclass_totals()
+        for stat in dbtotals:
+            typetable.add_row(stat.get('typeclass', '<error>'), stat.get('count', -1), "%.2f" % stat.get('percent', -1))
 
         # last N table
         objs = ObjectDB.objects.all().order_by("db_date_created")[
diff --git a/evennia/typeclasses/managers.py b/evennia/typeclasses/managers.py
index 5b7ffe362f..0877b14167 100644
--- a/evennia/typeclasses/managers.py
+++ b/evennia/typeclasses/managers.py
@@ -5,7 +5,8 @@ all Attributes and TypedObjects).
 
 """
 import shlex
-from django.db.models import Q, Count
+from django.db.models import F, Q, Count, ExpressionWrapper, FloatField
+from django.db.models.functions import Cast
 from evennia.utils import idmapper
 from evennia.utils.utils import make_iter, variable_from_module
 from evennia.typeclasses.attributes import Attribute
@@ -265,7 +266,7 @@ class TypedObjectManager(idmapper.manager.SharedMemoryManager):
             tagtype (str, optional): 'type' of Tag, by default
                 this is either `None` (a normal Tag), `alias` or
                 `permission`. This always apply to all queried tags.
-                
+
         Kwargs:
             match (str): ALL or ANY, determines whether the target object must match
                 ALL of the provided tags/categories or ANY single one. ANY will perform
@@ -499,7 +500,29 @@ class TypedObjectManager(idmapper.manager.SharedMemoryManager):
         if max_dbref is not None:
             retval = retval.filter(id__lte=self.dbref(max_dbref, reqhash=False))
         return retval
-
+        
+    def get_typeclass_totals(self, *args, **kwargs) -> object:
+        """
+        Returns a queryset of typeclass composition statistics.
+        
+        Returns:
+            qs (Queryset): A queryset of dicts containing the typeclass (name), 
+                the count of objects with that typeclass and a float representing
+                the percentage of objects associated with the typeclass.
+            
+        """
+        return self.values('db_typeclass_path').distinct().annotate(
+            # Get count of how many objects for each typeclass exist
+            count=Count('db_typeclass_path')
+        ).annotate(
+            # Rename db_typeclass_path field to something more human
+            typeclass=F('db_typeclass_path'),
+            # Calculate this class' percentage of total composition
+            percent=ExpressionWrapper(
+                ((F('count') / float(self.count())) * 100.0), output_field=FloatField()
+            ),
+        ).values('typeclass', 'count', 'percent')
+        
     def object_totals(self):
         """
         Get info about database statistics.
@@ -511,13 +534,8 @@ class TypedObjectManager(idmapper.manager.SharedMemoryManager):
                 object having that typeclass set on themselves).
 
         """
-        dbtotals = {}
-        typeclass_paths = set(self.values_list("db_typeclass_path", flat=True))
-        for typeclass_path in typeclass_paths:
-            dbtotals[typeclass_path] = self.filter(
-                db_typeclass_path=typeclass_path
-            ).count()
-        return dbtotals
+        stats = self.get_typeclass_totals().order_by('typeclass')
+        return {x.get('typeclass'):x.get('count') for x in stats}
 
     def typeclass_search(
         self, typeclass, include_children=False, include_parents=False