This PR is the first in a series that will
optimize looking up full names of group members.
The biggest source of slowness when opening a
group chat is looking up the full names of group
members in the search for duplicates. It is slow
because it requires multiple db queries for each
member.
The characterstic feature of this algorithm is the
iterative process of assigning names to signal
addresses. For example, some contacts' names may
be cached. For others, their profiles must be
fetched. For those without profiles, their phone
numbers must be formatted (which requires fetching
SignalAccounts). For those without phone numbers,
their user names must be formatted.
This PR creates a class called Refinery. Its job
is to make it easy to assign values to keys
through multiple passes, where each pass may
succeed only for a subset of keys.
This is useful because we will eventually issue a
single DB query for some of these passes.
36119e4367