From edc4c439d70a8c972ba9325f00beb8817a783233 Mon Sep 17 00:00:00 2001
From: Tanner Collin <git@tannercollin.com>
Date: Sat, 19 Oct 2019 07:33:06 +0000
Subject: [PATCH] Prefetch first images

---
 apiserver/feed.py     | 23 ++++++++++++++++++++++-
 webclient/src/Feed.js |  8 +++++++-
 2 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/apiserver/feed.py b/apiserver/feed.py
index 22e3c2c..a56e685 100644
--- a/apiserver/feed.py
+++ b/apiserver/feed.py
@@ -5,6 +5,7 @@ logging.basicConfig(
 
 import requests
 import time
+from bs4 import BeautifulSoup
 
 from feeds import hackernews, reddit, tildes
 
@@ -74,6 +75,19 @@ def get_article(url):
         logging.error('Problem getting article: {}'.format(str(e)))
         return ''
 
+def get_first_image(text):
+    soup = BeautifulSoup(text, features='html.parser')
+
+    try:
+        first_img = soup.find('img')
+        url = first_img['src']
+        headers = {'User-Agent': 'Twitterbot/1.0'}
+        length = requests.get(url, headers=headers).headers['Content-length']
+        if int(length) > 1000000: raise
+        return url
+    except:
+        return ''
+
 def update_story(story):
     res = {}
 
@@ -105,6 +119,8 @@ def update_story(story):
         story['text'] = get_article(story['url'])
         if not story['text']: return False
 
+        story['img'] = get_first_image(story['text'])
+
     return True
 
 if __name__ == '__main__':
@@ -116,6 +132,11 @@ if __name__ == '__main__':
     #news_story = test_news_cache[nid]
     #update_story(news_story)
 
-    print(get_article('https://www.bloomberg.com/news/articles/2019-09-23/xi-s-communists-under-pressure-as-high-prices-hit-china-workers'))
+    #print(get_article('https://www.bloomberg.com/news/articles/2019-09-23/xi-s-communists-under-pressure-as-high-prices-hit-china-workers'))
+
+    a = get_article('https://blog.joinmastodon.org/2019/10/mastodon-3.0/')
+    print(a)
+    u = get_first_image(a)
+    print(u)
 
     print('done')
diff --git a/webclient/src/Feed.js b/webclient/src/Feed.js
index c710264..740fd86 100644
--- a/webclient/src/Feed.js
+++ b/webclient/src/Feed.js
@@ -27,7 +27,7 @@ class Feed extends React.Component {
 
 					if (updated) {
 						localForage.clear();
-						result.stories.forEach(x => {
+						result.stories.forEach((x, i) => {
 							fetch('/api/' + x.id)
 								.then(res => res.json())
 								.then(result => {
@@ -36,6 +36,12 @@ class Feed extends React.Component {
 									this.props.updateCache(x.id, result.story);
 								}, error => {}
 							);
+
+							if (i < 20 && x.img) {
+								const img = new Image();
+								img.src = x.img;
+								console.log('prefetched image', x.img);
+							}
 						});
 					}
 				},