Source

File: wp-includes/ms-blogs.php

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 ( 'www.' === substr( $fields['domain'], 0, 4 ) ) {
				$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 ( 'www.' === substr( $fields['domain'], 0, 4 ) ) {
				$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 ? '' : 'short';
	$details = wp_cache_get( $blog_id . $all, 'blog-details' );

	if ( $details ) {
		if ( ! is_object( $details ) ) {
			if ( -1 == $details ) {
				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 ( -1 == $details ) {
					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 = WP_Site::get_instance( $blog_id );
		if ( ! $details ) {
			// Set the full cache.
			wp_cache_set( $blog_id, -1, 'blog-details' );
			return false;
		}
	}

	if ( ! $details instanceof WP_Site ) {
		$details = new WP_Site( $details );
	}

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

	$switched_blog = false;

	if ( get_current_blog_id() !== $blog_id ) {
		switch_to_blog( $blog_id );
		$switched_blog = true;
	}

	$details->blogname   = get_option( 'blogname' );
	$details->siteurl    = get_option( 'siteurl' );
	$details->post_count = get_option( 'post_count' );
	$details->home       = get_option( 'home' );

	if ( $switched_blog ) {
		restore_current_blog();
	}

	/**
	 * Filters a blog's details.
	 *
	 * @since MU (3.0.0)
	 * @deprecated 4.7.0 Use {@see 'site_details'} instead.
	 *
	 * @param object $details The blog details.
	 */
	$details = apply_filters_deprecated( 'blog_details', array( $details ), '4.7.0', 'site_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;
}