get_blog_details( int|string|array $fields = null, bool $get_all = true )

从blogs表和blog选项中检索blog的详细信息。
Retrieve the details for a blog from the blogs table and blog options.

参数（Parameters）

返回（Return）

源码（Source）

/**
 * Retrieve the details for a blog from the blogs table and blog options.
 *
 * @since MU
 *
 * @global wpdb $wpdb
 *
 * @param int|string|array $fields  Optional. A blog ID, a blog slug, or an array of fields to query against.
 *                                  If not specified the current blog ID is used.
 * @param bool             $get_all Whether to retrieve all details or only the details in the blogs table.
 *                                  Default is true.
 * @return object|false Blog details on success. False on failure.
 */
function get_blog_details( $fields = null, $get_all = true ) {
	global $wpdb;

	if ( is_array($fields ) ) {
		if ( isset($fields['blog_id']) ) {
			$blog_id = $fields['blog_id'];
		} elseif ( isset($fields['domain']) && isset($fields['path']) ) {
			$key = md5( $fields['domain'] . $fields['path'] );
			$blog = wp_cache_get($key, 'blog-lookup');
			if ( false !== $blog )
				return $blog;
			if ( substr( $fields['domain'], 0, 4 ) == 'www.' ) {
				$nowww = substr( $fields['domain'], 4 );
				$blog = $wpdb->get_row( $wpdb->prepare( "SELECT * FROM $wpdb->blogs WHERE domain IN (%s,%s) AND path = %s ORDER BY CHAR_LENGTH(domain) DESC", $nowww, $fields['domain'], $fields['path'] ) );
			} else {
				$blog = $wpdb->get_row( $wpdb->prepare( "SELECT * FROM $wpdb->blogs WHERE domain = %s AND path = %s", $fields['domain'], $fields['path'] ) );
			}
			if ( $blog ) {
				wp_cache_set($blog->blog_id . 'short', $blog, 'blog-details');
				$blog_id = $blog->blog_id;
			} else {
				return false;
			}
		} elseif ( isset($fields['domain']) && is_subdomain_install() ) {
			$key = md5( $fields['domain'] );
			$blog = wp_cache_get($key, 'blog-lookup');
			if ( false !== $blog )
				return $blog;
			if ( substr( $fields['domain'], 0, 4 ) == 'www.' ) {
				$nowww = substr( $fields['domain'], 4 );
				$blog = $wpdb->get_row( $wpdb->prepare( "SELECT * FROM $wpdb->blogs WHERE domain IN (%s,%s) ORDER BY CHAR_LENGTH(domain) DESC", $nowww, $fields['domain'] ) );
			} else {
				$blog = $wpdb->get_row( $wpdb->prepare( "SELECT * FROM $wpdb->blogs WHERE domain = %s", $fields['domain'] ) );
			}
			if ( $blog ) {
				wp_cache_set($blog->blog_id . 'short', $blog, 'blog-details');
				$blog_id = $blog->blog_id;
			} else {
				return false;
			}
		} else {
			return false;
		}
	} else {
		if ( ! $fields )
			$blog_id = get_current_blog_id();
		elseif ( ! is_numeric( $fields ) )
			$blog_id = get_id_from_blogname( $fields );
		else
			$blog_id = $fields;
	}

	$blog_id = (int) $blog_id;

	$all = $get_all == true ? '' : 'short';
	$details = wp_cache_get( $blog_id . $all, 'blog-details' );

	if ( $details ) {
		if ( ! is_object( $details ) ) {
			if ( $details == -1 ) {
				return false;
			} else {
				// Clear old pre-serialized objects. Cache clients do better with that.
				wp_cache_delete( $blog_id . $all, 'blog-details' );
				unset($details);
			}
		} else {
			return $details;
		}
	}

	// Try the other cache.
	if ( $get_all ) {
		$details = wp_cache_get( $blog_id . 'short', 'blog-details' );
	} else {
		$details = wp_cache_get( $blog_id, 'blog-details' );
		// If short was requested and full cache is set, we can return.
		if ( $details ) {
			if ( ! is_object( $details ) ) {
				if ( $details == -1 ) {
					return false;
				} else {
					// Clear old pre-serialized objects. Cache clients do better with that.
					wp_cache_delete( $blog_id, 'blog-details' );
					unset($details);
				}
			} else {
				return $details;
			}
		}
	}

	if ( empty($details) ) {
		$details = $wpdb->get_row( $wpdb->prepare( "SELECT * FROM $wpdb->blogs WHERE blog_id = %d /* get_blog_details */", $blog_id ) );
		if ( ! $details ) {
			// Set the full cache.
			wp_cache_set( $blog_id, -1, 'blog-details' );
			return false;
		}
	}

	if ( ! $get_all ) {
		wp_cache_set( $blog_id . $all, $details, 'blog-details' );
		return $details;
	}

	switch_to_blog( $blog_id );
	$details->blogname		= get_option( 'blogname' );
	$details->siteurl		= get_option( 'siteurl' );
	$details->post_count	= get_option( 'post_count' );
	restore_current_blog();

	/**
	 * Filter a blog's details.
	 *
	 * @since MU
	 *
	 * @param object $details The blog details.
	 */
	$details = apply_filters( 'blog_details', $details );

	wp_cache_set( $blog_id . $all, $details, 'blog-details' );

	$key = md5( $details->domain . $details->path );
	wp_cache_set( $key, $details, 'blog-lookup' );

	return $details;
}

笔记（Notes）