Improve performance

src/registrar/admin.py

@@ -1,6 +1,8 @@
 import logging
+import time
 from django import forms
-from django.db.models.functions import Concat
+from django.db.models.functions import Concat, Coalesce
+from django.db.models import Value, CharField
 from django.http import HttpResponse
 from django.shortcuts import redirect
 from django_fsm import get_available_FIELD_transitions
@@ -12,6 +14,7 @@ from django.http.response import HttpResponseRedirect
 from django.urls import reverse
 from epplibwrapper.errors import ErrorCode, RegistryError
 from registrar.models.domain import Domain
+from registrar.models.domain_application import DomainApplication
 from registrar.models.user import User
 from registrar.utility import csv_export
 from registrar.views.utility.mixins import OrderableFieldsMixin
@@ -707,6 +710,17 @@ class DomainInformationAdmin(ListHeaderAdmin):
         return readonly_fields  # Read-only fields for analysts
 
 
+class Timer:
+    def __enter__(self):
+        self.start = time.time()
+        return self  # This allows usage of the instance within the with block
+
+    def __exit__(self, *args):
+        self.end = time.time()
+        self.duration = self.end - self.start
+        logger.info(f"Execution time: {self.duration} seconds")
+
+
 class DomainApplicationAdminForm(forms.ModelForm):
     """Custom form to limit transitions to available transitions"""
 
@@ -753,11 +767,37 @@ class DomainApplicationAdmin(ListHeaderAdmin):
             """Lookup reimplementation, gets users of is_staff.
             Returns a list of tuples consisting of (user.id, user)
             """
-            privileged_users = User.objects.filter(is_staff=True).order_by("first_name", "last_name", "email")
+            logger.info("timing lookups")
-            return [(user.id, user) for user in privileged_users]
+            with Timer() as t:
+
+                # Select all investigators that are staff, then order by name and email
+                privileged_users = (
+                    DomainApplication.objects.select_related("investigator")
+                    .filter(investigator__is_staff=True)
+                    .order_by(
+                        "investigator__first_name", 
+                        "investigator__last_name", 
+                        "investigator__email"
+                    )
+                )
+
+                # Annotate the full name and return a values list that lookups can use
+                privileged_users_annotated = privileged_users.annotate(
+                    full_name=Coalesce(
+                        Concat(
+                            "investigator__first_name", Value(" "), "investigator__last_name", output_field=CharField()
+                        ),
+                        "investigator__email",
+                        output_field=CharField()
+                    )
+                ).values_list("investigator__id", "full_name")
+
+                return privileged_users_annotated
 
         def queryset(self, request, queryset):
             """Custom queryset implementation, filters by investigator"""
+            logger.info("timing queryset")
+            with Timer() as t:
                 if self.value() is None:
                     return queryset
                 else:
@@ -863,11 +903,15 @@ class DomainApplicationAdmin(ListHeaderAdmin):
     # lists in filter_horizontal are not sorted properly, sort them
     # by website
     def formfield_for_manytomany(self, db_field, request, **kwargs):
+        logger.info("timing formfield_for_manytomany")
+        with Timer() as t:
             if db_field.name in ("current_websites", "alternative_domains"):
                 kwargs["queryset"] = models.Website.objects.all().order_by("website")  # Sort websites
             return super().formfield_for_manytomany(db_field, request, **kwargs)
 
     def formfield_for_foreignkey(self, db_field, request, **kwargs):
+        logger.info("timing formfield_for_foreignkey")
+        with Timer() as t:
             # Removes invalid investigator options from the investigator dropdown
             if db_field.name == "investigator":
                 kwargs["queryset"] = User.objects.filter(is_staff=True)
@@ -876,6 +920,8 @@ class DomainApplicationAdmin(ListHeaderAdmin):
 
     # Trigger action when a fieldset is changed
     def save_model(self, request, obj, form, change):
+        logger.info("timing save_model")
+        with Timer() as t:
             if obj and obj.creator.status != models.User.RESTRICTED:
                 if change:  # Check if the application is being edited
                     # Get the original application from the database
@@ -941,7 +987,8 @@ class DomainApplicationAdmin(ListHeaderAdmin):
         admin user permissions and the application creator's status, so
         we'll use the baseline readonly_fields and extend it as needed.
         """
-
+        logger.info("timing get_readonly_fields")
+        with Timer() as t:
             readonly_fields = list(self.readonly_fields)
 
             # Check if the creator is restricted
@@ -961,6 +1008,8 @@ class DomainApplicationAdmin(ListHeaderAdmin):
             return readonly_fields
 
     def display_restricted_warning(self, request, obj):
+        logger.info("timing display_restricted_warning")
+        with Timer() as t:
             if obj and obj.creator.status == models.User.RESTRICTED:
                 messages.warning(
                     request,
@@ -968,6 +1017,8 @@ class DomainApplicationAdmin(ListHeaderAdmin):
                 )
 
     def change_view(self, request, object_id, form_url="", extra_context=None):
+        logger.info("timing change_view")
+        with Timer() as t:
             obj = self.get_object(request, object_id)
             self.display_restricted_warning(request, obj)
             return super().change_view(request, object_id, form_url, extra_context)