get_site_by_path

get_site_by_path: 这个函数通过域名和路径检索一个网站对象。它需要两个参数：要检索的网站的域名和路径。它返回网站对象。

按域名和路径检索最接近的匹配网站对象。

这不一定会返回一个完全匹配的域和路径。相反，它将域和路径分成几部分，然后用于匹配查询中最接近的可能性。

这个方法的目的是在引导过程中为请求的网站地址匹配一个网站对象。

function get_site_by_path( $domain, $path, $segments = null ) {
	$path_segments = array_filter( explode( '/', trim( $path, '/' ) ) );

	/**
	 * Filters the number of path segments to consider when searching for a site.
	 *
	 * @since 3.9.0
	 *
	 * @param int|null $segments The number of path segments to consider. WordPress by default looks at
	 *                           one path segment following the network path. The function default of
	 *                           null only makes sense when you know the requested path should match a site.
	 * @param string   $domain   The requested domain.
	 * @param string   $path     The requested path, in full.
	 */
	$segments = apply_filters( 'site_by_path_segments_count', $segments, $domain, $path );

	if ( null !== $segments && count( $path_segments ) > $segments ) {
		$path_segments = array_slice( $path_segments, 0, $segments );
	}

	$paths = array();

	while ( count( $path_segments ) ) {
		$paths[] = '/' . implode( '/', $path_segments ) . '/';
		array_pop( $path_segments );
	}

	$paths[] = '/';

	/**
	 * Determines a site by its domain and path.
	 *
	 * This allows one to short-circuit the default logic, perhaps by
	 * replacing it with a routine that is more optimal for your setup.
	 *
	 * Return null to avoid the short-circuit. Return false if no site
	 * can be found at the requested domain and path. Otherwise, return
	 * a site object.
	 *
	 * @since 3.9.0
	 *
	 * @param null|false|WP_Site $site     Site value to return by path. Default null
	 *                                     to continue retrieving the site.
	 * @param string             $domain   The requested domain.
	 * @param string             $path     The requested path, in full.
	 * @param int|null           $segments The suggested number of paths to consult.
	 *                                     Default null, meaning the entire path was to be consulted.
	 * @param string[]           $paths    The paths to search for, based on $path and $segments.
	 */
	$pre = apply_filters( 'pre_get_site_by_path', null, $domain, $path, $segments, $paths );
	if ( null !== $pre ) {
		if ( false !== $pre && ! $pre instanceof WP_Site ) {
			$pre = new WP_Site( $pre );
		}
		return $pre;
	}

	/*
	 * @todo
	 * Caching, etc. Consider alternative optimization routes,
	 * perhaps as an opt-in for plugins, rather than using the pre_* filter.
	 * For example: The segments filter can expand or ignore paths.
	 * If persistent caching is enabled, we could query the DB for a path <> '/'
	 * then cache whether we can just always ignore paths.
	 */

	// Either www or non-www is supported, not both. If a www domain is requested,
	// query for both to provide the proper redirect.
	$domains = array( $domain );
	if ( 'www.' === substr( $domain, 0, 4 ) ) {
		$domains[] = substr( $domain, 4 );
	}

	$args = array(
		'number'                 => 1,
		'update_site_meta_cache' => false,
	);

	if ( count( $domains ) > 1 ) {
		$args['domain__in']               = $domains;
		$args['orderby']['domain_length'] = 'DESC';
	} else {
		$args['domain'] = array_shift( $domains );
	}

	if ( count( $paths ) > 1 ) {
		$args['path__in']               = $paths;
		$args['orderby']['path_length'] = 'DESC';
	} else {
		$args['path'] = array_shift( $paths );
	}

	$result = get_sites( $args );
	$site   = array_shift( $result );

	if ( $site ) {
		return $site;
	}

	return false;
}