From 2d4cec4422fba603bde6a0222a599cadedaf346a Mon Sep 17 00:00:00 2001
From: Mouse Reeve <mousereeve@riseup.net>
Date: Sat, 22 May 2021 19:54:50 -0700
Subject: [PATCH] Improves shelf page query efficiency a little

---
 bookwyrm/views/helpers.py |  4 ++++
 bookwyrm/views/shelf.py   | 31 +++++++++++++++++++------------
 2 files changed, 23 insertions(+), 12 deletions(-)

diff --git a/bookwyrm/views/helpers.py b/bookwyrm/views/helpers.py
index 31e5f031..3dc02e0d 100644
--- a/bookwyrm/views/helpers.py
+++ b/bookwyrm/views/helpers.py
@@ -13,6 +13,10 @@ from bookwyrm.utils import regex
 
 def get_user_from_username(viewer, username):
     """helper function to resolve a localname or a username to a user"""
+    if viewer.localname == username:
+        # that's yourself, fool
+        return viewer
+
     # raises 404 if the user isn't found
     try:
         return models.User.viewer_aware_objects(viewer).get(localname=username)
diff --git a/bookwyrm/views/shelf.py b/bookwyrm/views/shelf.py
index 758e290e..99e22fa9 100644
--- a/bookwyrm/views/shelf.py
+++ b/bookwyrm/views/shelf.py
@@ -2,7 +2,7 @@
 from collections import namedtuple
 
 from django.db import IntegrityError
-from django.db.models import Count, OuterRef, Subquery, F, Q
+from django.db.models import OuterRef, Subquery
 from django.contrib.auth.decorators import login_required
 from django.core.paginator import Paginator
 from django.http import HttpResponseBadRequest, HttpResponseNotFound
@@ -28,7 +28,12 @@ class Shelf(View):
         """display a shelf"""
         user = get_user_from_username(request.user, username)
 
-        shelves = privacy_filter(request.user, user.shelf_set)
+        is_self = user == request.user
+
+        if is_self:
+            shelves = user.shelf_set
+        else:
+            shelves = privacy_filter(request.user, user.shelf_set)
 
         # get the shelf and make sure the logged in user should be able to see it
         if shelf_identifier:
@@ -53,26 +58,28 @@ class Shelf(View):
         if is_api_request(request):
             return ActivitypubResponse(shelf.to_activity(**request.GET))
 
-        reviews = privacy_filter(
-            request.user,
-            models.Review.objects.filter(
-                user=user,
-                rating__isnull=False,
-                book__id=OuterRef("id"),
-            ),
+        reviews = models.Review.objects.filter(
+            user=user,
+            rating__isnull=False,
+            book__id=OuterRef("id"),
         ).order_by("-published_date")
 
-        books = books.annotate(rating=Subquery(reviews.values("rating")[:1]))
+        if not is_self:
+            reviews = privacy_filter(request.user, reviews)
+
+        books = books.annotate(
+            rating=Subquery(reviews.values("rating")[:1])
+        ).prefetch_related("authors")
 
         paginated = Paginator(
-            books.order_by("-updated_date"),
+            books.order_by("-shelfbook__updated_date"),
             PAGE_LENGTH,
         )
 
         page = paginated.get_page(request.GET.get("page"))
         data = {
             "user": user,
-            "is_self": request.user == user,
+            "is_self": is_self,
             "shelves": shelves.all(),
             "shelf": shelf,
             "books": page,