Save the join membership event and updates it when necessary

src/github.com/matrix-org/dendrite/roomserver/input/membership.go

@@ -95,10 +95,9 @@ func updateMembership(
 			return nil, err
 		}
 	}
-	if old == new {
+	if old == new && new != "join" {
 		// If the membership is the same then nothing changed and we can return
-		// immediately. This should help speed up processing for display name
-		// changes where the membership is "join" both before and after.
+		// immediately.
 		return updates, nil
 	}
 
@@ -152,16 +151,20 @@ func updateToInviteMembership(
 func updateToJoinMembership(
 	mu types.MembershipUpdater, add *gomatrixserverlib.Event, updates []api.OutputEvent,
 ) ([]api.OutputEvent, error) {
-	// If the user is already marked as being joined then we can return immediately.
-	// TODO: Is this code reachable given the "old != new" guard in updateMembership?
+	// If the user is already marked as being joined, we call SetToJoin to update
+	// the event ID then we can return immediately. Retired is ignored as
 	if mu.IsJoin() {
+		_, err := mu.SetToJoin(add.Sender(), add.EventID(), true)
+		if err != nil {
+			return nil, err
+		}
 		return updates, nil
 	}
 	// When we mark a user as being joined we will invalidate any invites that
 	// are active for that user. We notify the consumers that the invites have
 	// been retired using a special event, even though they could infer this
 	// by studying the state changes in the room event stream.
-	retired, err := mu.SetToJoin(add.Sender())
+	retired, err := mu.SetToJoin(add.Sender(), add.EventID(), false)
 	if err != nil {
 		return nil, err
 	}

src/github.com/matrix-org/dendrite/roomserver/storage/membership_table.go

@@ -33,7 +33,7 @@ const membershipSchema = `
 -- and the room state tables.
 -- This table is updated in one of 3 ways:
 --   1) The membership of a user changes within the current state of the room.
---   2) An invite is received outside of a room over federation. 
+--   2) An invite is received outside of a room over federation.
 --   3) An invite is rejected outside of a room over federation.
 CREATE TABLE IF NOT EXISTS roomserver_membership (
 	room_nid BIGINT NOT NULL,
@@ -46,6 +46,11 @@ CREATE TABLE IF NOT EXISTS roomserver_membership (
 	-- The state the user is in within this room.
 	-- Default value is "membershipStateLeaveOrBan"
 	membership_nid BIGINT NOT NULL DEFAULT 1,
+	-- The ID of the "join" membership event.
+	-- This ID is updated if the join event gets updated (e.g. profile update).
+	-- This column is set to NULL if the user hasn't joined the room yet, e.g.
+	-- if the user was invited but hasn't joined yet.
+	event_id TEXT,
 	UNIQUE (room_nid, target_nid)
 );
 `
@@ -62,7 +67,7 @@ const selectMembershipForUpdateSQL = "" +
 	" WHERE room_nid = $1 AND target_nid = $2 FOR UPDATE"
 
 const updateMembershipSQL = "" +
-	"UPDATE roomserver_membership SET sender_nid = $3, membership_nid = $4" +
+	"UPDATE roomserver_membership SET sender_nid = $3, membership_nid = $4, event_id = $5" +
 	" WHERE room_nid = $1 AND target_nid = $2"
 
 type membershipStatements struct {
@@ -103,9 +108,14 @@ func (s *membershipStatements) selectMembershipForUpdate(
 func (s *membershipStatements) updateMembership(
 	txn *sql.Tx, roomNID types.RoomNID, targetUserNID types.EventStateKeyNID,
 	senderUserNID types.EventStateKeyNID, membership membershipState,
+	eventID string,
 ) error {
+	eID := sql.NullString{
+		String: eventID,
+		Valid:  len(eventID) > 0,
+	}
 	_, err := txn.Stmt(s.updateMembershipStmt).Exec(
-		roomNID, targetUserNID, senderUserNID, membership,
+		roomNID, targetUserNID, senderUserNID, membership, eID,
 	)
 	return err
 }

src/github.com/matrix-org/dendrite/roomserver/storage/storage.go

@@ -435,7 +435,7 @@ func (u *membershipUpdater) SetToInvite(event gomatrixserverlib.Event) (bool, er
 	}
 	if u.membership != membershipStateInvite {
 		if err = u.d.statements.updateMembership(
-			u.txn, u.roomNID, u.targetUserNID, senderUserNID, membershipStateInvite,
+			u.txn, u.roomNID, u.targetUserNID, senderUserNID, membershipStateInvite, "",
 		); err != nil {
 			return false, err
 		}
@@ -444,24 +444,32 @@ func (u *membershipUpdater) SetToInvite(event gomatrixserverlib.Event) (bool, er
 }
 
 // SetToJoin implements types.MembershipUpdater
-func (u *membershipUpdater) SetToJoin(senderUserID string) ([]string, error) {
+func (u *membershipUpdater) SetToJoin(senderUserID string, eventID string, isUpdate bool) ([]string, error) {
+	var inviteEventIDs []string
+
 	senderUserNID, err := u.d.assignStateKeyNID(u.txn, senderUserID)
 	if err != nil {
 		return nil, err
 	}
-	inviteEventIDs, err := u.d.statements.updateInviteRetired(
-		u.txn, u.roomNID, u.targetUserNID,
-	)
-	if err != nil {
-		return nil, err
+
+	// If this is a join event update, there is no invite to update
+	if !isUpdate {
+		inviteEventIDs, err = u.d.statements.updateInviteRetired(
+			u.txn, u.roomNID, u.targetUserNID,
+		)
+		if err != nil {
+			return nil, err
+		}
 	}
-	if u.membership != membershipStateJoin {
+
+	if u.membership != membershipStateJoin || isUpdate {
 		if err = u.d.statements.updateMembership(
-			u.txn, u.roomNID, u.targetUserNID, senderUserNID, membershipStateJoin,
+			u.txn, u.roomNID, u.targetUserNID, senderUserNID, membershipStateJoin, eventID,
 		); err != nil {
 			return nil, err
 		}
 	}
+
 	return inviteEventIDs, nil
 }
 
@@ -479,7 +487,7 @@ func (u *membershipUpdater) SetToLeave(senderUserID string) ([]string, error) {
 	}
 	if u.membership != membershipStateLeaveOrBan {
 		if err = u.d.statements.updateMembership(
-			u.txn, u.roomNID, u.targetUserNID, senderUserNID, membershipStateLeaveOrBan,
+			u.txn, u.roomNID, u.targetUserNID, senderUserNID, membershipStateLeaveOrBan, "",
 		); err != nil {
 			return nil, err
 		}

src/github.com/matrix-org/dendrite/roomserver/types/types.go

@@ -193,9 +193,9 @@ type MembershipUpdater interface {
 	// Set the state to invite.
 	// Returns whether this invite needs to be sent
 	SetToInvite(event gomatrixserverlib.Event) (needsSending bool, err error)
-	// Set the state to join.
+	// Set the state to join or updates the event ID in the database.
 	// Returns a list of invite event IDs that this state change retired.
-	SetToJoin(senderUserID string) (inviteEventIDs []string, err error)
+	SetToJoin(senderUserID string, eventID string, isUpdate bool) (inviteEventIDs []string, err error)
 	// Set the state to leave.
 	// Returns a list of invite event IDs that this state change retired.
 	SetToLeave(senderUserID string) (inviteEventIDs []string, err error)