Core_Upgrader::upgrade( object $current, array $args = array() ): string|false|WP_Error

Compatibility

Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.

Parameters

$currentobject

Response object for whether WordPress is current.

$argsarrayoptional

Arguments for upgrading WordPress core. Default empty array.Default: array()

• $pre_check_md5booldefault: true

  Whether to check the file checksums before attempting the upgrade.

• $attempt_rollbackbooldefault: false

  Whether to attempt to rollback the chances if there is a problem.

• $do_rollbackbooldefault: false

  Whether to perform this "upgrade" as a rollback.

Return value

string|false|WP_Error

New WordPress version on success, false or WP_Error on failure.

Performance profile

How much work a call to Core_Upgrader::upgrade() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.

Cost class

Expensive

Reaches an outbound HTTP request via wp_remote_post().

Scaling

Constant

No loop in the body: the same number of instructions runs whatever you pass in.

Instructions

31–296

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 385.

Plugin surface

2 hooks

Third-party callbacks on 'update_feedback', 'upgrader_process_complete' run inside this call, and their cost is not bounded by anything here.

Called by

1

1 place in core call this, so the cost is paid more often than your own code shows.

What it touches

• hookthird-party callbacksapply_filters()called directly
• sqldatabase query->delete()called directly
• transienttransientget_site_transient()one call below Core_Upgrader::upgrade()
• optionnetwork optionget_site_option()one call below Core_Upgrader::upgrade()
• httpoutbound HTTP requestwp_remote_post()one call below Core_Upgrader::upgrade()
• cacheobject cachewp_cache_flush()one call below Core_Upgrader::upgrade()

Further down the call graph this can also reach serialize and query. Those are the worst case, several calls deep and usually down an error path, not what a normal call pays.

What one call costs · 297 distinct outcomes

One number would be a lie: the work depends on which branch runs. These are every distinct cost Core_Upgrader::upgrade() can have, taken from its control-flow graph on PHP 8.5.

This body has more branch combinations than are worth enumerating, so the table covers the outcomes found first rather than every one that exists.

Hooks and filters fired · 4

4 hooks fire while Core_Upgrader::upgrade() runs, in this order:

1. 1
   apply_filters( update_feedback )filterline 137 (+71 into the body)

   Filters feedback messages displayed during the core update process.

2. 2
   apply_filters( update_feedback )filterline 201 (+135 into the body)

   Filters feedback messages displayed during the core update process.

3. 3
   apply_filters( update_feedback )filterline 204 (+138 into the body)

   Filters feedback messages displayed during the core update process.

4. 4
   do_action( upgrader_process_complete )actionline 221 (+155 into the body)

   Fires when the upgrader process is complete.

Uses · 22

• wp_parse_args()Merges user defined arguments into defaults array.
• is_wp_error()Checks whether the given variable is a WordPress Error.
• trailingslashit()Appends a trailing slash.
• apply_filters()Calls the callback functions that have been added to a filter hook.
• wp_version_check()Checks WordPress version against the newest version.
• __()Retrieves the translation of $text.
• wp_opcache_invalidate()Attempts to clear the opcode cache for an individual PHP file.
• update_core()Upgrades the core of WordPress.
• str_contains()Polyfill for `str_contains()` function added in PHP 8.0.
• do_action()Calls the callback functions that have been added to an action hook.
• delete_site_transient()Deletes a site transient.
• has_filter()Checks if any filter has been registered for a hook.

Used by · 1

• Core_Upgrader::upgrade()Upgrades WordPress core.

Source code

View on Trac ↗View on GitHub ↗

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 doing105		 * a reinstallation. If we cross the new_bundled version number, then use106		 * the new_bundled zip. Don't though if the constant is set to skip bundled items.107		 * If the API returns a no_content zip, go with it. Finally, default to the full zip.108		 */109		if ( $parsed_args['do_rollback'] && $current->packages->rollback ) {110			$to_download = 'rollback';111		} elseif ( $current->packages->partial && 'reinstall' !== $current->response && $wp_version === $current->partial_version && $partial ) {112			$to_download = 'partial';113		} elseif ( $current->packages->new_bundled && version_compare( $wp_version, $current->new_bundled, '<' )114			&& ( ! defined( 'CORE_UPGRADE_SKIP_NEW_BUNDLED' ) || ! CORE_UPGRADE_SKIP_NEW_BUNDLED ) ) {115			$to_download = 'new_bundled';116		} elseif ( $current->packages->no_content ) {117			$to_download = 'no_content';118		} else {119			$to_download = 'full';120		}121 122		// Lock to prevent multiple Core Updates occurring.123		$lock = WP_Upgrader::create_lock( 'core_updater', 15 * MINUTE_IN_SECONDS );124		if ( ! $lock ) {125			return new WP_Error( 'locked', $this->strings['locked'] );126		}127 128		$download = $this->download_package( $current->packages->$to_download, false );129 130		/*131		 * Allow for signature soft-fail.132		 * WARNING: This may be removed in the future.133		 */134		if ( is_wp_error( $download ) && $download->get_error_data( 'softfail-filename' ) ) {135			// Output the failure error as a normal feedback, and not as an error:136			/** This filter is documented in wp-admin/includes/update-core.php */137			apply_filters( 'update_feedback', $download->get_error_message() );138 139			// Report this failure back to WordPress.org for debugging purposes.140			wp_version_check(141				array(142					'signature_failure_code' => $download->get_error_code(),143					'signature_failure_data' => $download->get_error_data(),144				)145			);

Changelog

Introduced in 2.8.0. Unchanged from 6.7.7 through 7.1.0.

1. 6.7.7
2. 6.8.8
3. 6.9.7
4. 7.0.4
5. 7.1.0

Signature, return type and hooks compared across 5 parsed releases.

About this page

Parsed data

Generated from the wordpress-develop 7.1.0 tag, from src/wp-admin/includes/class-core-upgrader.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

Corrections

Something wrong on this page? Report it and it gets fixed in the next regeneration.