Add misc. doccomments

src/client/commands.rs

@@ -171,6 +171,10 @@ pub async fn handle_command(
     }
 }
 
+/// Handle an unexpected or erroneous response from the server.
+///
+/// This function checks the provided response and returns an appropriate error message.
+/// It is typically used in `match` branches for expecting a specific response type from the server.
 pub fn erroneous_server_response(
     response: Option<Result<Response, std::io::Error>>,
 ) -> anyhow::Result<()> {
@@ -190,6 +194,11 @@ pub fn erroneous_server_response(
     }
 }
 
+/// Print a hint about which name prefixes the user is authorized to manage
+/// by querying the server for valid name prefixes.
+///
+/// This function should be used when an authorization error occurs,
+/// to help the user understand which databases or users they are allowed to manage.
 pub async fn print_authorization_owner_hint(
     server_connection: &mut ClientToServerMessageStream,
 ) -> anyhow::Result<()> {

src/core/bootstrap.rs

@@ -176,6 +176,8 @@ pub fn drop_privs() -> anyhow::Result<()> {
     Ok(())
 }
 
+/// Bootstrap an internal server by forking a child process to run the server, giving it
+/// the other half of a Unix socket pair to communicate with the client process.
 fn bootstrap_internal_server_and_drop_privs(
     config_path: Option<PathBuf>,
 ) -> anyhow::Result<StdUnixStream> {
@@ -237,6 +239,10 @@ fn invoke_server_with_config(config_path: PathBuf) -> anyhow::Result<StdUnixStre
     }
 }
 
+/// Construct a MySQL connection pool that consists of exactly one connection.
+///
+/// This is used for the internal server in SUID/SGID mode, where the server session
+/// only ever will get a single client.
 async fn construct_single_connection_mysql_pool(
     config: &MysqlConfig,
 ) -> anyhow::Result<sqlx::MySqlPool> {
@@ -262,8 +268,10 @@ async fn construct_single_connection_mysql_pool(
     Ok(pool)
 }
 
-/// Run the server in the forked child process.
+/// Run a single server session in the forked process.
+///
 /// This function will not return, but will exit the process with a success code.
+/// The function assumes that it's caller has already forked the process.
 fn run_forked_server(
     config_path: PathBuf,
     server_socket: StdUnixStream,