Use count() instead of len() where possible. (#4760)

Improves performance a bit by using `.count()` directly instead of
loading everything and then use `len()` on it. SQL is always faster than
PHP.

Author: frjo

hypha/apply/dashboard/services.py

@@ -9,7 +9,7 @@ def get_paf_for_review(user, is_paf_approval_sequential):
     paf_approvals = PAFApprovals.objects.annotate(
         roles_count=Count("paf_reviewer_role__user_roles")
     ).filter(
-        roles_count=len(list(user.groups.all())),
+        roles_count=user.groups.count(),
         approved=False,
     )
 

hypha/apply/projects/templatetags/project_tags.py

@@ -171,7 +171,7 @@ def user_next_step_on_project(project, user, request=None):
             else:
                 matched_roles = PAFReviewersRole.objects.annotate(
                     roles_count=Count("user_roles")
-                ).filter(roles_count=len(user.groups.all()))
+                ).filter(roles_count=user.groups.count())
                 for group in user.groups.all():
                     matched_roles = matched_roles.filter(user_roles__id=group.id)
                 if not matched_roles:

hypha/apply/projects/views/payment.py

@@ -319,7 +319,7 @@ def form_valid(self, form):
             related=self.object,
         )
 
-        if len(self.project.invoices.all()) == 1:
+        if self.project.invoices.count() == 1:
             # remove Project waiting invoices task for applicant on first invoice
             remove_tasks_for_user(
                 code=PROJECT_WAITING_INVOICE,

hypha/apply/todo/services.py

@@ -23,7 +23,7 @@ def validate_user_uniqueness(code, user, related_obj):
         # if same task is already assigned to user's user_group
         user_group_matching_tasks = matching_tasks.annotate(
             group_count=Count("user_group")
-        ).filter(group_count=len(user.groups.all()))
+        ).filter(group_count=user.groups.count())
         for group in user.groups.all():
             user_group_matching_tasks = user_group_matching_tasks.filter(
                 user_group__id=group.id
@@ -45,7 +45,7 @@ def validate_user_groups_uniqueness(code, user_groups, related_obj):
     )
     user_group_matching_tasks = matching_tasks.annotate(
         group_count=Count("user_group")
-    ).filter(group_count=len(user_groups))
+    ).filter(group_count=user_groups.count())
     for group in user_groups:
         user_group_matching_tasks = user_group_matching_tasks.filter(
             user_group__id=group.id

hypha/apply/todo/views.py

@@ -147,7 +147,7 @@ def remove_tasks_for_user_group(code, user_group, related_obj):
     )
     user_group_matching_tasks = matching_tasks.annotate(
         group_count=Count("user_group")
-    ).filter(group_count=len(user_group.all()))
+    ).filter(group_count=user_group.count())
     for group in user_group.all():
         user_group_matching_tasks = user_group_matching_tasks.filter(
             user_group__id=group.id
@@ -190,7 +190,7 @@ def get_tasks_for_user(user):
         group_count=Count("user_group")
     )
     user_group_tasks = Task.objects.annotate(group_count=Count("user_group")).filter(
-        group_count=len(user.groups.all())
+        group_count=user.groups.count()
     )
     for group in user.groups.all():
         user_group_tasks = user_group_tasks.filter(user_group__id=group.id)