Source

File: wp-admin/includes/plugin.php

function get_plugin_page_hookname( $plugin_page, $parent_page ) {
	global $admin_page_hooks;

	$parent = get_admin_page_parent( $parent_page );

	$page_type = 'admin';
	if ( empty( $parent_page ) || 'admin.php' === $parent_page || isset( $admin_page_hooks[ $plugin_page ] ) ) {
		if ( isset( $admin_page_hooks[ $plugin_page ] ) ) {
			$page_type = 'toplevel';
		} elseif ( isset( $admin_page_hooks[ $parent ] ) ) {
			$page_type = $admin_page_hooks[ $parent ];
		}
	} elseif ( isset( $admin_page_hooks[ $parent ] ) ) {
		$page_type = $admin_page_hooks[ $parent ];
	}

	$plugin_name = preg_replace( '!\.php!', '', $plugin_page );

	return $page_type . '_page_' . $plugin_name;
}