core: request roster (#7121)

src/Simplex/Chat/Store/Postgres/Migrations.hs

@@ -39,6 +39,7 @@ import Simplex.Chat.Store.Postgres.Migrations.M20260531_member_removed_at
 import Simplex.Chat.Store.Postgres.Migrations.M20260601_relay_sent_web_domain
 import Simplex.Chat.Store.Postgres.Migrations.M20260602_group_roster
 import Simplex.Chat.Store.Postgres.Migrations.M20260603_simplex_name
+import Simplex.Chat.Store.Postgres.Migrations.M20260629_roster_catchup
 import Simplex.Messaging.Agent.Store.Shared (Migration (..))
 
 schemaMigrations :: [(String, Text, Maybe Text)]
@@ -77,7 +78,8 @@ schemaMigrations =
     ("20260531_member_removed_at", m20260531_member_removed_at, Just down_m20260531_member_removed_at),
     ("20260601_relay_sent_web_domain", m20260601_relay_sent_web_domain, Just down_m20260601_relay_sent_web_domain),
     ("20260602_group_roster", m20260602_group_roster, Just down_m20260602_group_roster),
-    ("20260603_simplex_name", m20260603_simplex_name, Just down_m20260603_simplex_name)
+    ("20260603_simplex_name", m20260603_simplex_name, Just down_m20260603_simplex_name),
+    ("20260629_roster_catchup", m20260629_roster_catchup, Just down_m20260629_roster_catchup)
   ]
 
 -- | The list of migrations in ascending order by date

src/Simplex/Chat/Store/Postgres/Migrations/M20260629_roster_catchup.hs

@@ -0,0 +1,41 @@
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE QuasiQuotes #-}
+
+module Simplex.Chat.Store.Postgres.Migrations.M20260629_roster_catchup where
+
+import Data.Text (Text)
+import Text.RawString.QQ (r)
+
+-- Roster catch-up bookkeeping. Three monotonic per-group roster versions with distinct roles - normally equal,
+-- diverging across gaps and failed transfers (applied_complete <= stored <= roster_version):
+--   roster_version (added in M20260602) - the GATE: highest version seen. Advanced by every accepted owner delta
+--     and by a roster apply. Revert protection: a completing roster older than this is rejected, since its
+--     snapshot would undo a newer applied delta.
+--   stored_roster_version - the blob HELD: the version of the roster blob actually stored (written with the blob).
+--     What a relay can re-serve; a failed blob receive leaves it behind the gate (which the delta still advances)
+--     until a later roster completes. Relay-side; on a member it is set but the blob is unused.
+--   applied_complete_roster_version - the COMPLETE frontier: highest version up to which the picture is contiguous.
+--     Advances by 1 on a contiguous delta and to the roster's version on apply, but stays put on a gapped delta.
+--     The subscriber's "what I have" for gap detection and the catch-up request: a value below the gate means
+--     missed versions, so each following delta re-asks the forwarding relay until a roster fills the frontier.
+-- Also adds group_members.roster_served_version - the newest version a relay re-served a given member, bounding
+-- reflected amplification (a member can't re-trigger a full serve at a version it was already served).
+-- Backfill an existing roster's stored and complete versions from roster_version: pre-upgrade the picture is
+-- contiguous up to roster_version (no gap detection existed), so a fresh NULL frontier would read every group's
+-- next delta as a gap and make every subscriber request a re-serve at once.
+m20260629_roster_catchup :: Text
+m20260629_roster_catchup =
+  [r|
+ALTER TABLE group_members ADD COLUMN roster_served_version BIGINT;
+ALTER TABLE groups ADD COLUMN stored_roster_version BIGINT;
+ALTER TABLE groups ADD COLUMN applied_complete_roster_version BIGINT;
+UPDATE groups SET stored_roster_version = roster_version, applied_complete_roster_version = roster_version WHERE roster_version IS NOT NULL;
+|]
+
+down_m20260629_roster_catchup :: Text
+down_m20260629_roster_catchup =
+  [r|
+ALTER TABLE group_members DROP COLUMN roster_served_version;
+ALTER TABLE groups DROP COLUMN stored_roster_version;
+ALTER TABLE groups DROP COLUMN applied_complete_roster_version;
+|]

src/Simplex/Chat/Store/Postgres/Migrations/chat_schema.sql

@@ -834,7 +834,8 @@ CREATE TABLE test_chat_schema.group_members (
     member_relations_vector bytea,
     relay_link bytea,
     member_pub_key bytea,
-    removed_at timestamp with time zone
+    removed_at timestamp with time zone,
+    roster_served_version bigint
 );
 
 
@@ -994,7 +995,9 @@ CREATE TABLE test_chat_schema.groups (
     roster_sending_owner_gm_id bigint,
     roster_broker_ts timestamp with time zone,
     roster_blob bytea,
-    group_domain_verified smallint
+    group_domain_verified smallint,
+    stored_roster_version bigint,
+    applied_complete_roster_version bigint
 );