Caches é SQL optimisations

photologue/models.py

@@ -3,7 +3,6 @@
 
 import logging
 import os
-import random
 import unicodedata
 from datetime import datetime
 from functools import partial
@@ -16,6 +15,7 @@ from django.conf import settings
 from django.core.exceptions import ValidationError
 from django.core.files.base import ContentFile
 from django.core.validators import RegexValidator
+from django.core.cache import caches
 from django.db import models
 from django.template.defaultfilters import slugify
 from django.urls import reverse
@@ -25,6 +25,8 @@ from django.utils.timezone import now
 from django.utils.translation import gettext_lazy as _
 from PIL import Image, ImageFile, ImageFilter
 
+
+
 logger = logging.getLogger("photologue.models")
 
 # Default limit for gallery.latest
@@ -184,13 +186,15 @@ class Gallery(models.Model):
     def sample(self, public=True):
         """Return a sample of photos, ordered at random."""
         count = 1
-        if count > self.photo_count():
-            count = self.photo_count()
+        nb = self.photo_count(public) #Optimisation don't do twice the SQL requests
+        if nb < count:
+            count = nb
+        
         if public:
             photo_set = self.photos.filter(is_public=True)
         else:
             photo_set = self.photos
-        return random.sample(list(photo_set), count)
+        return photo_set.order_by("?")[:count] # Use native SQL random
 
     def photo_count(self, public=True):
         """Return a count of all the photos in this gallery."""
@@ -721,10 +725,16 @@ class PhotoSizeCache:
 
     def __init__(self):
         self.__dict__ = self.__state
-        if not len(self.sizes):
-            sizes = PhotoSize.objects.all()
-            for size in sizes:
-                self.sizes[size.name] = size
+
+        cached = caches.get("PhotoSizeCache",None)
+        if cached is None :
+            if not len(self.sizes):
+                sizes = PhotoSize.objects.all()
+                for size in sizes:
+                    self.sizes[size.name] = size
+            caches.set("PhotoSizeCache",self)
+        else :
+            self = cached
 
     def reset(self):
         global size_method_map