[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. 4)
 * 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( 'plugins_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();
	}
});