Core_Upgrader

25class Core_Upgrader extends WP_Upgrader {26 27	/**28	 * Initializes the upgrade strings.29	 *30	 * @since 2.8.031	 */32	public function upgrade_strings() {33		$this->strings['up_to_date'] = __( 'WordPress is at the latest version.' );34		$this->strings['locked']     = __( 'Another update is currently in progress.' );35		$this->strings['no_package'] = __( 'Update package not available.' );36		/* translators: %s: Package URL. */37		$this->strings['downloading_package']   = sprintf( __( 'Downloading update from %s&#8230;' ), '<span class="code pre">%s</span>' );38		$this->strings['unpack_package']        = __( 'Unpacking the update&#8230;' );39		$this->strings['copy_failed']           = __( 'Could not copy files.' );40		$this->strings['copy_failed_space']     = __( 'Could not copy files. You may have run out of disk space.' );41		$this->strings['start_rollback']        = __( 'Attempting to restore the previous version.' );42		$this->strings['rollback_was_required'] = __( 'Due to an error during updating, WordPress has been restored to your previous version.' );43	}44 45	/**46	 * Upgrades WordPress core.47	 *48	 * @since 2.8.049	 *50	 * @global WP_Filesystem_Base $wp_filesystem                WordPress filesystem subclass.51	 * @global callable           $_wp_filesystem_direct_method52	 *53	 * @param object $current Response object for whether WordPress is current.54	 * @param array  $args {55	 *     Optional. Arguments for upgrading WordPress core. Default empty array.56	 *57	 *     @type bool $pre_check_md5    Whether to check the file checksums before58	 *                                  attempting the upgrade. Default true.59	 *     @type bool $attempt_rollback Whether to attempt to rollback the chances if60	 *                                  there is a problem. Default false.61	 *     @type bool $do_rollback      Whether to perform this "upgrade" as a rollback.62	 *                                  Default false.63	 * }64	 * @return string|false|WP_Error New WordPress version on success, false or WP_Error on failure.65	 */66	public function upgrade( $current, $args = array() ) {67		global $wp_filesystem;68 69		require ABSPATH . WPINC . '/version.php'; // $wp_version;70 71		$start_time = time();72 73		$defaults    = array(74			'pre_check_md5'                => true,75			'attempt_rollback'             => false,76			'do_rollback'                  => false,77			'allow_relaxed_file_ownership' => false,78		);79		$parsed_args = wp_parse_args( $args, $defaults );80 81		$this->init();82		$this->upgrade_strings();83 84		// Is an update available?85		if ( ! isset( $current->response ) || 'latest' === $current->response ) {86			return new WP_Error( 'up_to_date', $this->strings['up_to_date'] );87		}88 89		$res = $this->fs_connect( array( ABSPATH, WP_CONTENT_DIR ), $parsed_args['allow_relaxed_file_ownership'] );90		if ( ! $res || is_wp_error( $res ) ) {91			return $res;92		}93 94		$wp_dir = trailingslashit( $wp_filesystem->abspath() );95 96		$partial = true;97		if ( $parsed_args['do_rollback'] ) {98			$partial = false;99		} elseif ( $parsed_args['pre_check_md5'] && ! $this->check_files() ) {100			$partial = false;101		}102 103		/*104		 * If partial update is returned from the API, use that, unless we're doing