Expand description
Message-id to message lookup.
The reference engine keeps a per-connection dictionary
(outstanding_msgs_dict) keyed on msgid_t so that a response
arriving on the wire can be paired with its outstanding request in
constant time. Earlier stages introduced
crate::util::dict::MsgIndex (an ahash-backed
std::collections::HashMap) keyed on MsgId; this module
provides the message-flavored alias plus a thin newtype that adds
the verbs the message layer actually uses.