val read_msg_header : string -> int -> Hydro_types.msg_header
type msg_reader = Hydro_message.msg_reader
val read_msg : Hydro_types.msg_header -> msg_reader
val read_msg_chunk : msg_reader -> string -> int -> int -> Netbuffer.t -> int
val read_done : msg_reader -> bool
val write_msg_header : string -> int -> Hydro_types.msg_header -> unit
type msg_writer = Hydro_message.msg_writer
val write_msg : Hydro_types.msg_buffer -> msg_writer
val write_msg_chunk : msg_writer -> string -> int -> int -> int
val write_done : msg_writer -> bool