[Hummingbird Pro] - Fix Asset Optimization clearing the Page Cache randomly

hb-fix-ao-random-cache-clearing.php

<?php
/**
 * Plugin Name: [Hummingbird Pro] - Fix Asset Optimization clearing the Page Cache randomly (Rev. 5)
 * Description: Description: Prevents the Cache Clearing process to be triggered after an AO queue completed under specific circumstance [ This should be fixed in the plugin core, if this snippet still help you please contact our support team ]
 * Author: Anderson Salas @ WPMUDEV
 * Task: SLS-5702 / SLS-4239 / SLS-3756 / SLS-3786
 * Author URI: https://premium.wpmudev.org
 * License: GPLv2 or later
 */

add_action( 'wp_hummingbird_loaded', function() {
    if ( ! class_exists( '\Hummingbird\WP_Hummingbird' ) ) {
        return;
    }

    if ( ! class_exists( 'WPMUDEV_Hummingbird_Custom_Clear_Cache' ) ) {
        class WPMUDEV_Hummingbird_Custom_Clear_Cache {
            private static $instance;
            private $lock = false;
            private $hbmodules;
            
            public static function get_instance() {
                if ( null === self::$instance ) {
                    self::$instance = new self();
                }
                return self::$instance;
            }

            public function __construct() {
                $this->hbmodules = \Hummingbird\WP_Hummingbird::get_instance()->core->modules;
                $this->replace_hooks();
            }

            private function replace_hooks() {
                global $wp_filter;

                $callbacks = array(
                    'wphb_clear_page_cache' => array(
                        'clear_cache_action',
                        '\Hummingbird\Core\Modules\Page_Cache'
                    ),
                );

                foreach ( $callbacks as $tag => list( $hook_method, $hook_class ) ) {
                    if ( ! isset( $wp_filter[ $tag ] ) ) {
                        return;
                    }
                    foreach ( $wp_filter[ $tag ]->callbacks as $key => $callback_array ) {
                        foreach ( $callback_array as $c_key => $callback ) {
                            if ( substr_compare( $c_key, $hook_method, strlen( $c_key ) - strlen( $hook_method ), strlen( $hook_method ) ) === 0 ) {
                                if ( $callback[ 'function' ][0] instanceof $hook_class ){
                                    unset( $wp_filter[ $tag ]->callbacks[ $key ][ $c_key ] );
                                }
                            }
                        }
                    }
                }

                add_action( 'wphb_minify_process_queue', array( $this, 'pre_cron_process_queue' ), 9 );
                add_action( 'wp_footer', array( $this, 'lock_ao_queue' ), 9999 );
                add_action( 'wphb_clear_page_cache', array( $this, 'clear_cache_action' ) );
                add_action( 'wp_footer', array( $this, 'unlock_ao_queue' ), 10001 );
            }

            public function pre_cron_process_queue() {
                if ( ! isset( $this->hbmodules[ 'minify' ] ) ) {
                    return;
                }

                $hb_minify   = $this->hbmodules[ 'minify' ];
                $queue_count = count( $hb_minify->get_pending_persistent_queue() );

                if ( $queue_count <= 9 ) {
                    $this->lock_ao_queue();
                }
            }

            public function lock_ao_queue() {
                $this->lock = true;
            }

            public function unlock_ao_queue() {
                $this->lock = false;
            }

            public function clear_cache_action( $post_id = false ) {
                if ( ! isset( $this->hbmodules[ 'page_cache' ] ) ) {
                    return;
                }

                $hb_cache = $this->hbmodules[ 'page_cache' ];

                if ( $this->lock ) {
                    return;
                }

                // Divi-specific: Blocks the HB cache clear callback triggered by the et_core_clear_wp_cache() function
                //                if the AO queue is still being processed.
                if ( function_exists( 'et_core_clear_wp_cache' ) && get_transient( 'wphb-processing' ) ) {
                    return; 
                }

                // Divi-specific: Blocks the HB cache clear callback triggered by the et_core_clear_wp_cache() function
                //                if $post_id is FALSE/NULL to avoid clearing all the cache.
                if ( function_exists( 'et_core_clear_wp_cache' ) && doing_action( 'save_post' ) && empty( $post_id ) ) {
                    return;
                }

                call_user_func_array( array( $hb_cache, 'clear_cache_action' ), array( $post_id ) );
                $this->lock = false;
            }
        }
        WPMUDEV_Hummingbird_Custom_Clear_Cache::get_instance();
    }
});