<?php
/**
* The viewport image (VPI) class.
*
* Handles discovering above-the-fold images for posts/pages and stores the
* viewport image list per post (desktop & mobile). Coordinates with the
* remote svc via queue + cron.
*
* @since 4.7
* @package LiteSpeed
*/
namespace LiteSpeed;
defined( 'WPINC' ) || exit();
/**
* Generate and manage ViewPort Images (VPI) for pages.
*/
class VPI extends Cloud_Queue_Svc {
/**
* Log tag for debug output.
*
* @var string
*/
const LOG_TAG = '[VPI]';
/**
* VPI Desktop Meta name.
*
* @since 7.6
* @var string
*/
const POST_META = 'litespeed_vpi_list';
/**
* VPI Mobile Meta name.
*
* @since 7.6
* @var string
*/
const POST_META_MOBILE = 'litespeed_vpi_list_mobile';
/**
* Init.
*
* @since 4.7
*/
public function __construct() {
$this->_summary = self::get_summary();
}
/**
* Svc id slug — drives queue type, Cloud::SVC_VPI, and summary key prefix.
*
* @return string
*/
protected function _svc_id() {
return 'vpi';
}
/**
* Response field carrying the viewport image data.
*
* @return string
*/
protected function _data_key() {
return 'data_vpi';
}
/**
* UI templates read `last_request` directly (settings_vpi.tpl.php,
* dashboard.tpl.php). Keep the legacy unsuffixed key.
*
* @return string
*/
protected function _last_request_key() {
return 'last_request';
}
/**
* Build the request body for Cloud::post.
*
* @param string $queue_k Queue key.
* @param array $v Queue item.
* @return array
*/
protected function _build_payload( $queue_k, $v ) {
return [
'url' => $v['url'],
'queue_k' => $queue_k,
'user_agent' => $v['user_agent'],
'is_mobile' => ! empty( $v['is_mobile'] ) ? 1 : 0,
];
}
/**
* Persist the viewport image list to post meta. Empty/null payload is
* persisted as an empty list (matches pre-refactor VPI behavior) so the
* post is marked processed and not re-queued.
*
* @param mixed $data VPI data (array, string, or null).
* @param string $queue_k Queue key.
* @param array $v Queue item.
* @return bool
*/
protected function _save_result( $data, $queue_k, $v ) {
$name = ! empty( $v['is_mobile'] ) ? self::POST_META_MOBILE : self::POST_META;
if ( is_array( $data ) ) {
$urldecode = array_map( 'urldecode', $data );
} elseif ( null === $data || '' === $data ) {
$urldecode = '';
} else {
$urldecode = urldecode( (string) $data );
}
self::debug( 'save data_vpi', $urldecode );
$this->cls( 'Metabox' )->save( (int) $v['post_id'], $name, $urldecode );
return true;
}
/**
* Queue the current page for VPI generation.
*
* @since 4.7
* @return void
*/
public function add_to_queue() {
$is_mobile = $this->_separate_mobile();
$request_url = Utility::request_url();
if ( ! apply_filters( 'litespeed_vpi_should_queue', true, $request_url ) ) {
return;
}
// Sanitize user agent coming from the server superglobal.
$ua = ! empty( $_SERVER['HTTP_USER_AGENT'] )
? sanitize_text_field( wp_unslash( $_SERVER['HTTP_USER_AGENT'] ) )
: '';
// Store it to prepare for cron.
$this->_queue = $this->load_queue( 'vpi' );
if ( count( $this->_queue ) >= $this->_max_queue_size() ) {
self::debug( 'Queue is full - ' . $this->_max_queue_size() );
return;
}
$home_id = (int) get_option( 'page_for_posts' );
if ( ! is_singular() && ! ( $home_id > 0 && is_home() ) ) {
self::debug( 'not single post ID' );
return;
}
$post_id = is_home() ? $home_id : get_the_ID();
$queue_k = ( $is_mobile ? 'mobile' : '' ) . ' ' . $request_url;
if ( ! empty( $this->_queue[ $queue_k ] ) ) {
self::debug( 'queue k existed ' . $queue_k );
return;
}
$this->_queue[ $queue_k ] = [
'url' => apply_filters( 'litespeed_vpi_url', $request_url ),
'post_id' => $post_id,
'user_agent' => substr( $ua, 0, 200 ),
'is_mobile' => $is_mobile,
]; // Current UA will be used to request.
$this->save_queue( 'vpi', $this->_queue );
self::debug( 'Added queue_vpi [url] ' . $queue_k . ' [UA] ' . $ua );
// Prepare cache tag for later purge.
Tag::add( 'VPI.' . md5( $queue_k ) );
}
}