core.php 20.3 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667
<?php

namespace HM\BackUpWordPress;

/**
 * Handles anything that needs to be
 * done when the plugin is updated
 */
function update() {

	// Update from backUpWordPress 0.4.5
	if ( get_option( 'bkpwp_max_backups' ) ) {

		// Carry over the custom path
		if ( $legacy_path = get_option( 'bkpwppath' ) ) {
			update_option( 'hmbkp_path', $legacy_path );
		}

		// Options to remove
		$legacy_options = array(
			'bkpwp_archive_types',
			'bkpwp_automail_from',
			'bkpwp_domain',
			'bkpwp_domain_path',
			'bkpwp_easy_mode',
			'bkpwp_excludelists',
			'bkpwp_install_user',
			'bkpwp_listmax_backups',
			'bkpwp_max_backups',
			'bkpwp_presets',
			'bkpwp_reccurrences',
			'bkpwp_schedules',
			'bkpwp_calculation',
			'bkpwppath',
			'bkpwp_status_config',
			'bkpwp_status',
		);

		foreach ( $legacy_options as $option ) {
			delete_option( $option );
		}

		global $wp_roles;

		$wp_roles->remove_cap( 'administrator', 'manage_backups' );
		$wp_roles->remove_cap( 'administrator', 'download_backups' );

		wp_clear_scheduled_hook( 'bkpwp_schedule_bkpwp_hook' );

	}

	// Version 1 to 2
	if ( get_option( 'hmbkp_plugin_version' ) && version_compare( '2.0', get_option( 'hmbkp_plugin_version' ), '>' ) ) {

		/**
		 * Setup a backwards compatible schedule
		 */
		$legacy_schedule = new Scheduled_Backup( 'backup' );

		// Backup type
		if ( ( defined( 'HMBKP_FILES_ONLY' ) && HMBKP_FILES_ONLY ) || get_option( 'hmbkp_files_only' ) ) {
			$legacy_schedule->set_type( 'file' );
		} elseif ( ( defined( 'HMBKP_DATABASE_ONLY' ) && HMBKP_DATABASE_ONLY ) || get_option( 'hmbkp_database_only' ) ) {
			$legacy_schedule->set_type( 'database' );
		} else {
			$legacy_schedule->set_type( 'complete' );
		}

		// Daily schedule time
		if ( defined( 'HMBKP_DAILY_SCHEDULE_TIME' ) && HMBKP_DAILY_SCHEDULE_TIME ) {
			$legacy_schedule->set_schedule_start_time( strtotime( HMBKP_DAILY_SCHEDULE_TIME ) );
		}

		// Backup schedule
		$legacy_schedule->set_reoccurrence( get_option( 'hmbkp_schedule_frequency', 'daily' ) );

		// Automatic backups disabled?
		if ( ( defined( 'HMBKP_DISABLE_AUTOMATIC_BACKUP' ) && HMBKP_DISABLE_AUTOMATIC_BACKUP ) || get_option( 'hmbkp_disable_automatic_backup' ) ) {
			$legacy_schedule->set_reoccurrence( 'manually' );
		}

		// Max backups
		if ( defined( 'HMBKP_MAX_BACKUPS' ) && is_numeric( HMBKP_MAX_BACKUPS ) ) {
			$legacy_schedule->set_max_backups( (int) HMBKP_MAX_BACKUPS );
		} else {
			$legacy_schedule->set_max_backups( (int) get_option( 'hmbkp_max_backups', 10 ) );
		}

		// Excludes
		if ( get_option( 'hmbkp_excludes' ) ) {
			$legacy_schedule->set_excludes( get_option( 'hmbkp_excludes' ) );
		}

		// Backup email
		if ( defined( 'HMBKP_EMAIL' ) && is_email( HMBKP_EMAIL ) ) {
			$legacy_schedule->set_service_options( 'HMBKP_Email_Service', array( 'email' => HMBKP_EMAIL ) );
		} elseif ( is_email( get_option( 'hmbkp_email_address' ) ) ) {
			$legacy_schedule->set_service_options( 'HMBKP_Email_Service', array( 'email' => get_option( 'hmbkp_email_address' ) ) );
		}

		// Set the archive filename to what it used to be
		$legacy_schedule->backup_filename = implode( '-', array( get_bloginfo( 'name' ), 'backup', current_time( 'Y-m-d-H-i-s' ) ) ) . '.zip';

		$legacy_schedule->save();

		$legacy_path = get_option( 'hmbkp_path' );

		if ( $legacy_path ) {

			// Prepend 'backup-' to the beginning of any legacy backups so they are picked up by the legacy schedule
			if ( $handle = opendir( $legacy_path ) ) {
				while ( false !== ( $file = readdir( $handle ) ) ) {
					if ( 'zip' === pathinfo( $file, PATHINFO_EXTENSION ) ) {
						rename( trailingslashit( $legacy_path ) . $file, trailingslashit( $legacy_path ) . 'backup-' . $file );
					}
				}
				closedir( $handle );
			}

			PATH::get_instance()->move_old_backups( $legacy_path );

		}

		// Remove the legacy options
		foreach ( array( 'hmbkp_database_only', 'hmbkp_files_only', 'hmbkp_max_backups', 'hmbkp_email_address', 'hmbkp_email', 'hmbkp_schedule_frequency', 'hmbkp_disable_automatic_backup' ) as $option_name ) {
			delete_option( $option_name );
		}
	}

	// Update from 2.x to 3.0
	if ( get_option( 'hmbkp_plugin_version' ) && version_compare( '2.0', get_option( 'hmbkp_plugin_version' ), '>' ) ) {

		// Remove the plugin data cache
		delete_transient( 'hmbkp_plugin_data' );

	}

	// Update to 3.1
	if ( get_option( 'hmbkp_plugin_version' ) && version_compare( '3.0', get_option( 'hmbkp_plugin_version' ), '>' ) ) {

		// Remove the plugin data cache
		delete_option( 'hmbkp_path' );
		delete_option( 'hmbkp_default_path' );

	}

	// update to 3.1.4
	if ( get_option( 'hmbkp_plugin_version' ) && version_compare( '3.1.4', get_option( 'hmbkp_plugin_version' ), '>' ) ) {

		$old_option_names = array(
			'HM\BackUpWordPressDropbox\Dropbox_Service'    => 'dropbox',
			'HMBKP_DX_Backup_Service'                      => 'dropbox',
			'HM\BackUpWordPressFTP\FTP_Backup_Service'     => 'ftp',
			'HMBKP_FTP_Backup_Service'                     => 'ftp',
			'HM\BackUpWordPressGDrive\Google_Drive_BackUp' => 'google-drive',
			'HMBKP_GDV_Backup_Service'                     => 'google-drive',
			'HM\BackUpWordPressRackspace\RackSpace_BackUp' => 'rackspace-cloud',
			'HMBKP_RSC_Backup_Service'                     => 'rackspace-cloud',
			'HM\BackUpWordPressS3\S3_Backup'               => 's3',
			'HMBKP_S3_Backup_Service'                      => 's3',
			'HM\BackUpWordPressWinAzure\WinAzure_Backup'   => 'azure',
			'HMBKP_WAZ_Backup_Service'                     => 'azure',
			'HM\BackUpWordPress\Email_Service'             => 'email',
		);

		global $wpdb;

		// Get all schedule options with a SELECT query and delete them.
		$schedules = $wpdb->get_col( $wpdb->prepare( "SELECT option_name FROM $wpdb->options WHERE option_name LIKE %s", 'hmbkp_schedule_%' ) );

		if ( 0 < count( $schedules ) ) {

			// Access each schedules settings to see if the addon settings names need to be be updated to the new naming convention which uses the service slug generated from the $name property.
			foreach ( $schedules as $schedule_id ) {

				// Load the settings for this schedule into an array
				// so we can loop through the different service settings
				$schedule_settings = get_option( $schedule_id );

				// Iterate over each schedule setting for this schedule and check its name against our array.
				foreach ( $schedule_settings as $key => $val ) {
					// Find the current element key in our control array and get its value. Set a new element in the settings array with the found value as its key. Aka rename the element key
					if ( array_key_exists( $key, $old_option_names ) ) {

						// move the value to our new key
						$schedule_settings[ $old_option_names[ $key ] ] = $schedule_settings[ $key ];

						unset( $schedule_settings[ $key ] );

					}
				}

				// Save back to the DB
				update_option( $schedule_id, $schedule_settings );
			}
		}
	}

	// Update to 3.1.5
	if ( get_option( 'hmbkp_plugin_version' ) && version_compare( '3.1.5', get_option( 'hmbkp_plugin_version' ), '>' ) ) {

		// Delete all transients
		$transients = array(
			'hmbkp_plugin_data',
			'hmbkp_directory_filesizes',
			'hmbkp_directory_filesizes_running',
			'hmbkp_wp_cron_test_beacon',
			'hm_backdrop',
		);

		array_map( 'delete_transient', $transients );

		// Clear duplicate schedules on multisite
		if ( is_multisite() ) {

			// get current blogs from DB
			$blogs = wp_get_sites();

			foreach ( $blogs as $blog ) {

				switch_to_blog( get_current_blog_id() );

				if ( is_main_site( get_current_blog_id() ) ) {
					continue;
				}

				global $wpdb;

				// Get the schedule options
				$schedules = $wpdb->get_col( $wpdb->prepare( "SELECT option_name FROM $wpdb->options WHERE option_name LIKE %s", 'hmbkp_schedule_%' ) );

				// clear schedules
				foreach ( array_map( function ( $item ) {
					return ltrim( $item, 'hmbkp_schedule_' );
				}, $schedules ) as $item ) {
					wp_clear_scheduled_hook( 'hmbkp_schedule_hook', array( 'id' => $item ) );
				}

				// delete options
				array_map( 'delete_option', $schedules );

				array_map( 'delete_option', array( 'hmbkp_enable_support', 'hmbkp_plugin_version', 'hmbkp_path', 'hmbkp_default_path', 'hmbkp_upsell' ) );

				// Delete all transients
				array_map( 'delete_transient', array( 'hmbkp_plugin_data', 'hmbkp_directory_filesizes', 'hmbkp_directory_filesize_running', 'timeout_hmbkp_wp_cron_test_beacon', 'hmbkp_wp_cron_test_beacon' ) );

			}

			restore_current_blog();
		}
	}

	// Update from 3.3.0
	if ( get_option( 'hmbkp_plugin_version' ) && version_compare( '3.3.0', get_option( 'hmbkp_plugin_version' ), '>' ) ) {

		$schedules = Schedules::get_instance();

		// Loop through all schedules and re-set the reccurrence to include hmbkp_
		foreach ( $schedules->get_schedules() as $schedule ) {

			$reoccurrence = $schedule->get_reoccurrence();

			if ( 'manually' !== $reoccurrence && strpos( $reoccurrence, 'hmbkp_' ) === 0 ) {
				$schedule->set_reoccurrence( substr( $reoccurrence, 6 ) );
			}

			$schedule->save();

		}
	}

	// Update from 3.3.4
	if ( get_option( 'hmbkp_plugin_version' ) && version_compare( '3.4.0', get_option( 'hmbkp_plugin_version' ), '>' ) ) {
		delete_transient( 'hmbkp_directory_filesizes' );
	}

	// Every update
	if ( get_option( 'hmbkp_plugin_version' ) && version_compare( Plugin::PLUGIN_VERSION, get_option( 'hmbkp_plugin_version' ), '>' ) ) {

		require_once( HMBKP_PLUGIN_PATH . 'classes/class-setup.php' );

		\HMBKP_Setup::deactivate();

		Path::get_instance()->protect_path( 'reset' );

	}

	// Update the stored version
	if ( get_option( 'hmbkp_plugin_version' ) !== Plugin::PLUGIN_VERSION ) {
		update_option( 'hmbkp_plugin_version', Plugin::PLUGIN_VERSION );
	}

}

/**
 * Setup the default backup schedules
 */
function setup_default_schedules() {

	$schedules = Schedules::get_instance();

	if ( $schedules->get_schedules() ) {
		return;
	}

	/**
	 * Schedule a database backup daily and store backups
	 * for the last 2 weeks
	 */
	$database_daily = new Scheduled_Backup( (string) time() );
	$database_daily->set_type( 'database' );
	$database_daily->set_schedule_start_time( determine_start_time( 'daily', array( 'hours' => '23', 'minutes' => '0' ) ) );
	$database_daily->set_reoccurrence( 'daily' );
	$database_daily->set_max_backups( 7 );
	$database_daily->save();

	/**
	 * Schedule a complete backup to run weekly and store backups for
	 * the last 3 months
	 */
	$complete_weekly = new Scheduled_Backup( (string) ( time() + 1 ) );
	$complete_weekly->set_type( 'complete' );
	$complete_weekly->set_schedule_start_time( determine_start_time( 'weekly', array( 'day_of_week' => 'sunday', 'hours' => '3', 'minutes' => '0' ) ) );
	$complete_weekly->set_reoccurrence( 'weekly' );
	$complete_weekly->set_max_backups( 3 );
	$complete_weekly->save();

	$schedules->refresh_schedules();

	add_action( 'admin_notices', function() {
		echo '<div id="hmbkp-warning" class="updated fade"><p><strong>' . __( 'BackUpWordPress has set up your default schedules.', 'backupwordpress' ) . '</strong> ' . __( 'By default BackUpWordPress performs a daily backup of your database and a weekly backup of your database &amp; files. You can modify these schedules.', 'backupwordpress' ) . '</p></div>';
	} );

}

add_action( 'admin_init', '\HM\BackUpWordPress\setup_default_schedules', 11 );

/**
 * Return an array of cron schedules
 *
 * @param $schedules
 * @return array $reccurrences
 */
function cron_schedules( $schedules = array() ) {

	$schedules += array(
		'hourly'      => array( 'interval' => HOUR_IN_SECONDS, 'display' => __( 'Once Hourly', 'backupwordpress' ) ),
		'twicedaily'  => array( 'interval' => 12 * HOUR_IN_SECONDS, 'display' => __( 'Twice Daily', 'backupwordpress' ) ),
		'daily'       => array( 'interval' => DAY_IN_SECONDS, 'display' => __( 'Once Daily', 'backupwordpress' ) ),
		'weekly'      => array( 'interval' => WEEK_IN_SECONDS, 'display' => __( 'Once Weekly', 'backupwordpress' ) ),
		'fortnightly' => array( 'interval' => 2 * WEEK_IN_SECONDS, 'display' => __( 'Once Every Two Weeks', 'backupwordpress' ) ),
		'monthly'     => array( 'interval' => 30 * DAY_IN_SECONDS, 'display' => __( 'Once Monthly', 'backupwordpress' ) ),
	);

	return $schedules;
}

add_filter( 'cron_schedules', '\HM\BackUpWordPress\cron_schedules' );

/**
 * Recursively delete a directory including
 * all the files and sub-directories.
 *
 * @param string $dir
 * @return bool
 * @return bool|WP_Error
 */
function rmdirtree( $dir ) {

	if ( false !== strpos( Path::get_home_path(), $dir ) ) {
		return new WP_Error( 'hmbkp_invalid_action_error', sprintf( __( 'You can only delete directories inside your WordPress installation', 'backupwordpress' ) ) );
	}

	if ( is_file( $dir ) ) {
		@unlink( $dir );
	}

	if ( ! is_dir( $dir ) || ! is_readable( $dir ) ) {
		return false;
	}

	$files = new \RecursiveIteratorIterator( new \RecursiveDirectoryIterator( $dir, \RecursiveDirectoryIterator::SKIP_DOTS ), \RecursiveIteratorIterator::CHILD_FIRST, \RecursiveIteratorIterator::CATCH_GET_CHILD );

	foreach ( $files as $file ) {

		if ( $file->isDir() ) {
			@rmdir( $file->getPathname() );
		} else {
			@unlink( $file->getPathname() );
		}
	}

	@rmdir( $dir );

	return true;
}

/**
 * Check if a backup is possible with regards to file
 * permissions etc.
 *
 * @return bool
 */
function is_backup_possible() {

	if ( ! wp_is_writable( Path::get_path() ) || ! is_dir( Path::get_path() ) ) {
		return false;
	}

	if ( ! is_readable( Path::get_root() ) ) {
		return false;
	}

	if ( disk_space_low() ) {
		return false;
	}

	if ( ! Requirement_Mysqldump_Command_Path::test() && ! Requirement_PDO::test() ) {
		return false;
	}

	if ( ! Requirement_Zip_Command_Path::test() && ! Requirement_Zip_Archive::test() ) {
		return false;
	}

	return true;
}

/**
 * Get the max email attachment filesize
 *
 * Can be overridden by defining HMBKP_ATTACHMENT_MAX_FILESIZE
 *
 * return int the filesize
 */
function get_max_attachment_size() {

	$max_size = '10mb';

	if ( defined( 'HMBKP_ATTACHMENT_MAX_FILESIZE' ) && wp_convert_hr_to_bytes( HMBKP_ATTACHMENT_MAX_FILESIZE ) ) {
		$max_size = HMBKP_ATTACHMENT_MAX_FILESIZE;
	}

	return wp_convert_hr_to_bytes( $max_size );

}

function is_path_accessible( $dir ) {

	// Path is inaccessible
	if ( strpos( $dir, Path::get_home_path() ) === false ) {
		return false;
	}

	return true;
}

/**
 * List of schedules
 *
 * @return array
 */
function get_cron_schedules() {
	return cron_schedules();
}

/**
 * @param string $type the type of the schedule
 * @param array $times {
 *     An array of time arguments. Optional.
 *
 *     @type int $minutes          The minute to start the schedule on. Defaults to current time + 10 minutes. Accepts
 *                                 any valid `date( 'i' )` output.
 *     @type int $hours            The hour to start the schedule on. Defaults to current time + 10 minutes. Accepts
 *                                 any valid `date( 'G' )` output.
 *     @type string $day_of_week   The day of the week to start the schedule on. Defaults to current time + 10 minutes. Accepts
 *                                 any valid `date( 'l' )` output.
 *     @type int $day_of_month     The day of the month to start the schedule on. Defaults to current time + 10 minutes. Accepts
 *                                 any valid `date( 'j' )` output.
 *     @type int $now              The current time. Defaults to `time()`. Accepts any valid timestamp.
 *
 * }
 * @return int $timestamp Returns the resulting timestamp on success and Int 0 on failure
 */
function determine_start_time( $type, $times = array() ) {

	// Default to in 10 minutes
	if ( ! empty( $times['now'] ) ) {
		$default_timestamp = $times['now'] + 600;

	} else {
		$default_timestamp = time() + 600;
	}

	$default_times = array(
		'minutes'      => date( 'i', $default_timestamp ),
		'hours'        => date( 'G', $default_timestamp ),
		'day_of_week'  => date( 'l', $default_timestamp ),
		'day_of_month' => date( 'j', $default_timestamp ),
		'now'          => time(),
	);

	$args = wp_parse_args( $times, $default_times );

	$intervals = get_cron_schedules();

	// Allow the hours and minutes to be overwritten by a constant
	if ( defined( 'HMBKP_SCHEDULE_TIME' ) && HMBKP_SCHEDULE_TIME ) {
		$hm = HMBKP_SCHEDULE_TIME;
	} else { // The hour and minute that the schedule should start on
		$hm = $args['hours'] . ':' . $args['minutes'] . ':00';
	}

	switch ( $type ) {

		case 'hourly' :
		case 'daily' :
		case 'twicedaily':

			// The next occurance of the specified time
			$schedule_start = $hm;
			break;

		case 'weekly' :
		case 'fortnightly' :

			// The next day of the week at the specified time
			$schedule_start = $args['day_of_week'] . ' ' . $hm;
			break;

		case 'monthly' :

			// The occurance of the time on the specified day of the month
			$schedule_start = date( 'F', $args['now'] ) . ' ' . $args['day_of_month'] . ' ' . $hm;

			// If we've already gone past that day this month then we'll need to start next month
			if ( strtotime( $schedule_start, $args['now'] ) <= $args['now'] ) {
				$schedule_start = date( 'F', strtotime( '+ 1 month', $args['now'] ) )  . ' ' . $args['day_of_month'] . ' ' . $hm;
			}

			// If that's still in the past then we'll need to jump to next year
			if ( strtotime( $schedule_start, $args['now'] ) <= $args['now'] ) {
				$schedule_start = date( 'F', strtotime( '+ 1 month', $args['now'] ) )  . ' ' . $args['day_of_month'] . ' ' . date( 'Y', strtotime( '+ 1 year', $args['now'] ) ) . ' ' . $hm;
			}

			break;

		default :

			return 0;

	}

	$timestamp = strtotime( $schedule_start, $args['now'] );

	// Convert to UTC
	$timestamp -= get_option( 'gmt_offset' ) * 3600;

	// If the scheduled time already passed then keep adding the interval until we get to a future date
	while ( $timestamp <= $args['now'] ) {
		$timestamp += $intervals[ $type ]['interval'];
	}

	return $timestamp;

}

/**
 * Helper function for creating safe action URLs.
 *
 * @param string $action Callback function name.
 * @param array $query_args Additional GET params.
 *
 * @return string
 */
function admin_action_url( $action, array $query_args = array() ) {

	$query_args = array_merge( $query_args, array( 'action' => 'hmbkp_' . $action ) );

	return esc_url( wp_nonce_url( add_query_arg( $query_args, admin_url( 'admin-post.php' ) ), 'hmbkp_' . $action, 'hmbkp-' . $action . '_nonce' ) );
}

/**
 * OS dependant way to pipe stderr to null
 *
 * @return string The exec argument to pipe stderr to null
 */
function ignore_stderr() {

	// If we're on Windows
	if ( DIRECTORY_SEPARATOR == '\\' ) {
		return '2>nul';
	}

	// Or Unix
	return '2>/dev/null';

}

/**
 * Return the contents of `$directory` as a single depth list ordered by total filesize.
 *
 * Will schedule background threads to recursively calculate the filesize of subdirectories.
 * The total filesize of each directory and subdirectory is cached in a transient for 1 week.
 *
 * @param string $directory The directory to list
 *
 * @todo doesn't really belong in this class, should just be a function
 * @return array            returns an array of files ordered by filesize
 */
function list_directory_by_total_filesize( $directory, Excludes $excludes ) {

	$files = $files_with_no_size = $empty_files = $files_with_size = $unreadable_files = array();

	if ( ! is_dir( $directory ) ) {
		return $files;
	}

	$finder = new \Symfony\Component\Finder\Finder();
	$finder->followLinks();
	$finder->ignoreDotFiles( false );
	$finder->ignoreUnreadableDirs();
	$finder->depth( '== 0' );

	$site_size = new Site_Size( 'file', $excludes );

	$files = $finder->in( $directory );

	foreach ( $files as $entry ) {

		// Get the total filesize for each file and directory
		$filesize = $site_size->filesize( $entry );

		if ( $filesize ) {

			// If there is already a file with exactly the same filesize then let's keep increasing the filesize of this one until we don't have a clash
			while ( array_key_exists( $filesize, $files_with_size ) ) {
				$filesize ++;
			}

			$files_with_size[ $filesize ] = $entry;

		} elseif ( 0 === $filesize ) {
			$empty_files[] = $entry;
		} else {
			$files_with_no_size[] = $entry;
		}
	}

	// Sort files by filesize, largest first
	krsort( $files_with_size );

	// Add 0 byte files / directories to the bottom
	$files = $files_with_size + array_merge( $empty_files, $unreadable_files );

	// Add directories that are still calculating to the top
	if ( $files_with_no_size ) {

		// We have to loop as merging or concatenating the array would re-flow the keys which we don't want because the filesize is stored in the key
		foreach ( $files_with_no_size as $entry ) {
			array_unshift( $files, $entry );
		}
	}

	return $files;

}