feat: speedup feed generation

boards/helpers.py

@@ -0,0 +1,9 @@
+from collections import defaultdict
+
+
+def regroup_articles_by_feed(articles_list):
+    articles_dict = defaultdict(list)
+    for article in articles_list:
+        articles_dict[article.feed_id].append(article)
+    return articles_dict
+

boards/models.py

@@ -1,6 +1,7 @@
 import uuid
 from datetime import datetime, timedelta
 
+from django.conf import settings
 from django.contrib.humanize.templatetags.humanize import naturaltime
 from django.db import models
 from django.db.models import JSONField
@@ -140,13 +141,6 @@ class BoardFeed(models.Model):
     def last_articles(self):
         return self.articles.all()[:15 * self.columns]
 
-    def articles_by_column(self):
-        articles = self.articles.all()[:self.articles_per_column * self.columns]
-        return [
-            (column, articles[column * self.articles_per_column:self.articles_per_column * (column + 1)])
-            for column in range(self.columns)
-        ]
-
     def natural_last_article_at(self):
         if not self.last_article_at:
             return None

boards/templatetags/articles.py

@@ -0,0 +1,12 @@
+from django import template
+
+register = template.Library()
+
+
+@register.simple_tag()
+def articles_by_column(articles_grouped_by_feed, feed):
+    articles = articles_grouped_by_feed[feed.id][0:feed.articles_per_column * feed.columns]
+    return [
+        (column, articles[column * feed.articles_per_column:feed.articles_per_column * (column + 1)])
+        for column in range(feed.columns)
+    ]

boards/views.py

@@ -7,7 +7,8 @@ from django.views.decorators.cache import cache_page
 from django.views.decorators.http import last_modified
 
 from boards.cache import board_last_modified_at
-from boards.models import Board, BoardBlock, BoardFeed
+from boards.helpers import regroup_articles_by_feed
+from boards.models import Board, BoardBlock, BoardFeed, Article
 
 
 @cache_page(settings.STATIC_PAGE_CACHE_SECONDS)
@@ -28,11 +29,16 @@ def board(request, board_slug):
         return cached_page
 
     blocks = BoardBlock.objects.filter(board=board)
-    feeds = BoardFeed.objects.select_related("articles").filter(board=board)
+    feeds = BoardFeed.objects.select_related("block").filter(board=board)
+    articles = Article.objects.select_related("feed").filter(
+        board=board,
+        created_at__gt=datetime.utcnow() - timedelta(days=settings.OLD_ARTICLES_CLEANUP_AFTER_DAYS)
+    )
     result = render(request, "board.html", {
         "board": board,
         "blocks": blocks,
         "feeds": feeds,
+        "articles_grouped_by_feed": regroup_articles_by_feed(articles),
     })
     cache.set(f"board_{board.slug}", result, settings.BOARD_CACHE_SECONDS)
     return result

templates/feeds/simple.html

@@ -1,8 +1,11 @@
 {% load static %}
 {% load text_filters %}
 {% load bleach_tags %}
+{% load articles %}
 
-{% for column, articles in feed.articles_by_column %}
+{% articles_by_column articles_grouped_by_feed feed as feed_articles_by_column %}
+
+{% for column, articles in feed_articles_by_column %}
     <div class="feed {% if column > 1 %}hide-on-iphone{% endif %}">
         {% if feed.name %}
             <div class="feed-title {% if column != 0 %}feed-title-hidden{% endif %}">