[IMP] website_blog: avoid exists() in loop

`tags_list()` is called in loops to get nicely formatted URL in blog tag button
but doing an exists here will do everytime an SQL query regardless of the
cache.

We can safely remove the call to `exists()` as the `tag_ids` parameter is
coming from the controller `active_tag_ids` key which is already ensuring the
exists condition.

It make also the number of requests determinists for test with a random number
of tags. From between 200 ~ 300 queries (depending number of tags)-> 116

task-2211013

Co-authored-by: Romain Derie <rde@odoo.com>
Co-authored-by: Jeremy Kersten <jke@odoo.com>

addons/website_blog/controllers/main.py

@@ -22,12 +22,12 @@ class WebsiteBlog(http.Controller):
     _post_comment_per_page = 10
 
     def tags_list(self, tag_ids, current_tag):
-        tag_ids = list(tag_ids) # required to avoid using the same list
+        tag_ids = list(tag_ids)  # required to avoid using the same list
         if current_tag in tag_ids:
             tag_ids.remove(current_tag)
         else:
             tag_ids.append(current_tag)
-        tag_ids = request.env['blog.tag'].browse(tag_ids).exists()
+        tag_ids = request.env['blog.tag'].browse(tag_ids)
         return ','.join(slug(tag) for tag in tag_ids)
 
     def nav_list(self, blog=None):
@@ -57,6 +57,7 @@ class WebsiteBlog(http.Controller):
     def _prepare_blog_values(self, blogs, blog=False, date_begin=False, date_end=False, tags=False, state=False, page=False):
         """ Prepare all values to display the blogs index page or one specific blog"""
         BlogPost = request.env['blog.post']
+        BlogTag = request.env['blog.tag']
 
         # prepare domain
         domain = request.website.website_domain()
@@ -66,15 +67,16 @@ class WebsiteBlog(http.Controller):
 
         if date_begin and date_end:
             domain += [("post_date", ">=", date_begin), ("post_date", "<=", date_end)]
-
         active_tag_ids = tags and [unslug(tag)[1] for tag in tags.split(',')] or []
+        active_tags = BlogTag
         if active_tag_ids:
-            fixed_tag_slug = ",".join(slug(t) for t in request.env['blog.tag'].browse(active_tag_ids).exists())
+            active_tags = BlogTag.browse(active_tag_ids).exists()
+            fixed_tag_slug = ",".join(slug(t) for t in active_tags)
             if fixed_tag_slug != tags:
                 new_url = request.httprequest.full_path.replace("/tag/%s" % tags, "/tag/%s" % fixed_tag_slug, 1)
                 if new_url != request.httprequest.full_path:  # check that really replaced and avoid loop
                     return request.redirect(new_url, 301)
-            domain += [('tag_ids', 'in', active_tag_ids)]
+            domain += [('tag_ids', 'in', active_tags.ids)]
 
         if request.env.user.has_group('website.group_website_designer'):
             count_domain = domain + [("website_published", "=", True), ("post_date", "<=", fields.Datetime.now())]
@@ -127,7 +129,7 @@ class WebsiteBlog(http.Controller):
             'pager': pager,
             'posts': posts.with_prefetch(post_ids),
             'tag': tags,
-            'active_tag_ids': active_tag_ids,
+            'active_tag_ids': active_tags.ids,
             'domain': domain,
             'state_info': state and {"state": state, "published": published_count, "unpublished": unpublished_count},
             'blogs': blogs,

addons/website_blog/tests/test_performance.py

@@ -2,11 +2,12 @@
 # Part of Odoo. See LICENSE file for full copyright and licensing details.
 
 from odoo.addons.website.tests.test_performance import UtilPerf
+import random
 
 
 class TestBlogPerformance(UtilPerf):
     def test_10_perf_sql_blog_standard_data(self):
-        self.assertEqual(self._get_url_hot_query('/blog'), 50)
+        self.assertEqual(self._get_url_hot_query('/blog'), 40)
 
     def test_20_perf_sql_blog_bigger_data_scaling(self):
         BlogPost = self.env['blog.post']
@@ -18,4 +19,19 @@ class TestBlogPerformance(UtilPerf):
         for blog_post in blog_posts:
             blog_post.tag_ids += blog_tags
             blog_tags = blog_tags[:-1]
-        self.assertEqual(self._get_url_hot_query('/blog'), 116)
+        self.assertEqual(self._get_url_hot_query('/blog'), 38)
+
+        self.assertEqual(self._get_url_hot_query(blog_post[0].website_url), 61)
+
+    def test_30_perf_sql_blog_bigger_data_random(self):
+        BlogPost = self.env['blog.post']
+        BlogTag = self.env['blog.tag']
+        blogs = self.env['blog.blog'].search([])
+        blog_tags = BlogTag.create([{'name': 'New Blog Tag Test %s' % i} for i in range(1, 50)])
+        BlogPost.create([{'name': 'New Blog Post Test %s' % i, 'is_published': True, 'blog_id': blogs[random.randint(0, 1)].id} for i in range(1, 100)])
+        blog_posts = BlogPost.search([])
+        for blog_post in blog_posts:
+            blog_post.write({'tag_ids': [[6, 0, random.choices(blog_tags.ids, k=random.randint(0, len(blog_tags)))]]})
+        self.assertEqual(self._get_url_hot_query('/blog'), 38)
+
+        self.assertEqual(self._get_url_hot_query(blog_post[0].website_url), 61)