watchtower+lnrpc: remove AckedUpdates from ClientSession struct

In this commit, we start making use of the new ListClientSession
functional options added in the previous commit. We use the functional
options in order to calculate the max commit heights per channel on the
construction of the tower client. We also use the options to count the
total number of acked and committed updates. With this commit, we are
also able to completely remove the AckedUpdates member of the
ClientSession since it is no longer used anywhere in the code.

watchtower/wtdb/client_db_test.go

@@ -48,12 +48,12 @@ func (h *clientDBHarness) insertSession(session *wtdb.ClientSession,
 	require.ErrorIs(h.t, err, expErr)
 }
 
-func (h *clientDBHarness) listSessions(
-	id *wtdb.TowerID) map[wtdb.SessionID]*wtdb.ClientSession {
+func (h *clientDBHarness) listSessions(id *wtdb.TowerID,
+	opts ...wtdb.ClientSessionListOption) map[wtdb.SessionID]*wtdb.ClientSession {
 
 	h.t.Helper()
 
-	sessions, err := h.db.ListClientSessions(id)
+	sessions, err := h.db.ListClientSessions(id, opts...)
 	require.NoError(h.t, err, "unable to list client sessions")
 
 	return sessions
@@ -520,11 +520,7 @@ func testCommitUpdate(h *clientDBHarness) {
 	// Assert that the committed update appears in the client session's
 	// CommittedUpdates map when loaded from disk and that there are no
 	// AckedUpdates.
-	dbSession := h.listSessions(nil)[session.ID]
-	checkCommittedUpdates(h.t, dbSession, []wtdb.CommittedUpdate{
-		*update1,
-	})
-	checkAckedUpdates(h.t, dbSession, nil)
+	h.assertUpdates(session.ID, []wtdb.CommittedUpdate{*update1}, nil)
 
 	// Try to commit the same update, which should succeed due to
 	// idempotency (which is preserved when the breach hint is identical to
@@ -534,11 +530,7 @@ func testCommitUpdate(h *clientDBHarness) {
 	require.Equal(h.t, lastApplied, lastApplied2)
 
 	// Assert that the loaded ClientSession is the same as before.
-	dbSession = h.listSessions(nil)[session.ID]
-	checkCommittedUpdates(h.t, dbSession, []wtdb.CommittedUpdate{
-		*update1,
-	})
-	checkAckedUpdates(h.t, dbSession, nil)
+	h.assertUpdates(session.ID, []wtdb.CommittedUpdate{*update1}, nil)
 
 	// Generate another random update and try to commit it at the identical
 	// sequence number. Since the breach hint has changed, this should fail.
@@ -553,12 +545,10 @@ func testCommitUpdate(h *clientDBHarness) {
 
 	// Check that both updates now appear as committed on the ClientSession
 	// loaded from disk.
-	dbSession = h.listSessions(nil)[session.ID]
-	checkCommittedUpdates(h.t, dbSession, []wtdb.CommittedUpdate{
+	h.assertUpdates(session.ID, []wtdb.CommittedUpdate{
 		*update1,
 		*update2,
-	})
-	checkAckedUpdates(h.t, dbSession, nil)
+	}, nil)
 
 	// Finally, create one more random update and try to commit it at index
 	// 4, which should be rejected since 3 is the next slot the database
@@ -567,12 +557,20 @@ func testCommitUpdate(h *clientDBHarness) {
 	h.commitUpdate(&session.ID, update4, wtdb.ErrCommitUnorderedUpdate)
 
 	// Assert that the ClientSession loaded from disk remains unchanged.
-	dbSession = h.listSessions(nil)[session.ID]
-	checkCommittedUpdates(h.t, dbSession, []wtdb.CommittedUpdate{
+	h.assertUpdates(session.ID, []wtdb.CommittedUpdate{
 		*update1,
 		*update2,
-	})
-	checkAckedUpdates(h.t, dbSession, nil)
+	}, nil)
+}
+
+func perAckedUpdate(updates map[uint16]wtdb.BackupID) func(
+	_ *wtdb.ClientSession, seq uint16, id wtdb.BackupID) {
+
+	return func(_ *wtdb.ClientSession, seq uint16,
+		id wtdb.BackupID) {
+
+		updates[seq] = id
+	}
 }
 
 // testAckUpdate asserts the behavior of AckUpdate.
@@ -628,9 +626,7 @@ func testAckUpdate(h *clientDBHarness) {
 
 	// Assert that the ClientSession loaded from disk has one update in it's
 	// AckedUpdates map, and that the committed update has been removed.
-	dbSession := h.listSessions(nil)[session.ID]
-	checkCommittedUpdates(h.t, dbSession, nil)
-	checkAckedUpdates(h.t, dbSession, map[uint16]wtdb.BackupID{
+	h.assertUpdates(session.ID, nil, map[uint16]wtdb.BackupID{
 		1: update1.BackupID,
 	})
 
@@ -645,9 +641,7 @@ func testAckUpdate(h *clientDBHarness) {
 	h.ackUpdate(&session.ID, 2, 2, nil)
 
 	// Assert that both updates exist as AckedUpdates when loaded from disk.
-	dbSession = h.listSessions(nil)[session.ID]
-	checkCommittedUpdates(h.t, dbSession, nil)
-	checkAckedUpdates(h.t, dbSession, map[uint16]wtdb.BackupID{
+	h.assertUpdates(session.ID, nil, map[uint16]wtdb.BackupID{
 		1: update1.BackupID,
 		2: update2.BackupID,
 	})
@@ -663,6 +657,19 @@ func testAckUpdate(h *clientDBHarness) {
 	h.ackUpdate(&session.ID, 4, 3, wtdb.ErrUnallocatedLastApplied)
 }
 
+func (h *clientDBHarness) assertUpdates(id wtdb.SessionID,
+	expectedPending []wtdb.CommittedUpdate,
+	expectedAcked map[uint16]wtdb.BackupID) {
+
+	ackedUpdates := make(map[uint16]wtdb.BackupID)
+	_ = h.listSessions(
+		nil, wtdb.WithPerAckedUpdate(perAckedUpdate(ackedUpdates)),
+	)
+	dbSession := h.listSessions(nil)[id]
+	checkCommittedUpdates(h.t, dbSession, expectedPending)
+	checkAckedUpdates(h.t, ackedUpdates, expectedAcked)
+}
+
 // checkCommittedUpdates asserts that the CommittedUpdates on session match the
 // expUpdates provided.
 func checkCommittedUpdates(t *testing.T, session *wtdb.ClientSession,
@@ -682,7 +689,7 @@ func checkCommittedUpdates(t *testing.T, session *wtdb.ClientSession,
 
 // checkAckedUpdates asserts that the AckedUpdates on a session match the
 // expUpdates provided.
-func checkAckedUpdates(t *testing.T, session *wtdb.ClientSession,
+func checkAckedUpdates(t *testing.T, actualUpdates,
 	expUpdates map[uint16]wtdb.BackupID) {
 
 	// We promote nil expUpdates to an initialized map since the database
@@ -692,7 +699,7 @@ func checkAckedUpdates(t *testing.T, session *wtdb.ClientSession,
 		expUpdates = make(map[uint16]wtdb.BackupID)
 	}
 
-	require.Equal(t, expUpdates, session.AckedUpdates)
+	require.Equal(t, expUpdates, actualUpdates)
 }
 
 // TestClientDB asserts the behavior of a fresh client db, a reopened client db,