Eliminate the concept of 'Recipients' (plural). There is now just
a 'Recipient', which contains an Address that is either an individual
or a group ID.
MMS groups now exist as part of the group database, just like push
groups.
// FREEBIE
This was a holdover from Signal's origins as a pure SMS app.
It causes problems, depends on undefined device specific behavior,
and should no longer be necessary now that we have all the
information we need to E164 all numbers.
// FREEBIE
1) On the push side, this message is a flag in PushMessageContent.
Any secure message with that flag will terminate the current
sessin.
2) On the SMS side, there is an "end session" wire type and
the convention that a message with this wire type must be
secure and contain the string "TERMINATE."
1) In addition to the Recipient interface, there is now
RecipientDevice. A Recipient can have multiple corresponding
RecipientDevices. All addressing is done to a Recipient, but
crypto sessions and transport delivery are done to
RecipientDevice.
2) The Push transport handles the discovery and session setup
of additional Recipient devices.
3) Some internal rejiggering of Groups.
1) We now try to hand out cursors at a minimum. There has always been
a fairly clean insertion layer that handles encrypting message bodies,
but the process of decrypting message bodies has always been less than
ideal. Here we introduce a "Reader" interface that will decrypt message
bodies when appropriate and return objects that encapsulate record state.
No more MessageDisplayHelper. The MmsSmsDatabase interface is also more
sane.
2) We finally rid ourselves of the technical debt associated with TextSecure's
initial usage of the default SMS DB. In that world, we weren't able to use
anything other than the default "Inbox, Outbox, Sent" types to describe a
message, and had to overload the message content itself with a set of
local "prefixes" to describe what it was (encrypted, asymetric encrypted,
remote encrypted, a key exchange, procssed key exchange), and so on.
This includes a major schema update that transforms the "type" field into
a bitmask that describes everything that used to be encoded in a prefix,
and prefixes have been completely eliminated from the system.
No more Prefix.java
3) Refactoring of the MultipartMessageHandler code. It's less of a mess, and
hopefully more clear as to what's going on.
The next step is to remove what we can from SmsTransportDetails and genericize
that interface for a GCM equivalent.
Alan Evans