your rotating banner system (/banners.php) is inefficient because it's impossible for users to cache these images in their browsers. everyone is constantly re-downloading previously-seen banners.
you can see if a file is already cached or is downloaded by refreshing a page (e.g.
https://leftypol.org/banners.php ) by checking http responses in firefox in the Network tab in Firefox Developer Tools (ctrl+shift+i) and seeing if it says "cached" under the "Transferred" column for the file
you can instead make it so twig serves the direct path to a random image from your banners folder instead of sending it to your inlined banners.php image file stream so that browsers can actually cache these images. this can speed up frequent visitors' page loads and reduce a bit of bandwidth per frequent visitor.
1. go to /inc/lib/Twig/Extensions/Extension/Tinyboard.php
2. add this line in that list of Twig extension functions:
new Twig_SimpleFunction('random_banner_url', 'twig_random_banner_url'),(don't forget to put a comma at the end of that previous item or you'll get php error / blank page)
3. at the end of the file add this function definition:
function twig_random_banner_url() {
$path = dirname(__DIR__, 5) . '/banners/';
$isDirEmpty = true;
if (!file_exists($path)) {
return '/static/blank.gif';
}
$handle = opendir($path);
while (false !== ($entry = readdir($handle))) {
if ($entry != "." && $entry != "..") {
$isDirEmpty = false;
break;
}
}
closedir($handle);
if (!$isDirEmpty) {
$files = scandir($path);
$files = array_diff($files, array('.', '..'));
return '/banners/' . $files[array_rand($files)];
}
return '/static/blank.gif';
}4. go to /templates/index.html, and change
<img class="board_image" src="{{ config.url_banner }}"to
<img class="board_image" src="{{ random_banner_url() }}"5. do the exact same thing in #4 for /templates/thread.html, /templates/generic_page.html, and /templates/themes/index/index.html
6. rebuild all boards/threads in mod.php and test new banner system
obviously you need to test this in a dev environment first, i did this on vichan but it looks like it's identical on lainchan. the only minor drawback is that the banner changes on each thread/index based on user actions (a new reply, thread, delete, mod action, etc.) instead of refreshing the browser due to twig's caching system, but because leftypol has high enough traffic this will not be a problem, it will change frequently enough and it's worth it for the improved page load times and minor bandwidth savings of frequent visitors not having to constantly re-download previously-seen banner images. also in theory this may reduce cpu usage a bit because the banners.php opcode is no longer executed each time any user refreshes his browser or goes to a different page, whereas this new twig function would execute only on user actions which are obviously far less frequent than refreshes / page loads. the other minor issue is it will ignore whatever you set $config['url_banner'] in instance-config.php, it will only pull images from a "/banners" folder if it exists, can't think of a way right now to have this twig function work together with that, you can put a TODO comment on this function to change it later, i don't think it's a real priority.