make Selector a pointer type

internal/datasourcev2/polling_data_source.go

@@ -22,7 +22,7 @@ type PollingResponse struct {
 	events   []fdv2proto.Event
 	cached   bool
 	intent   fdv2proto.IntentCode
-	selector fdv2proto.Selector
+	selector *fdv2proto.Selector
 }
 
 func (p *PollingResponse) Events() []fdv2proto.Event {
@@ -37,7 +37,7 @@ func (p *PollingResponse) Intent() fdv2proto.IntentCode {
 	return p.intent
 }
 
-func (p *PollingResponse) Selector() fdv2proto.Selector {
+func (p *PollingResponse) Selector() *fdv2proto.Selector {
 	return p.selector
 }
 
@@ -47,7 +47,7 @@ func NewCachedPollingResponse() *PollingResponse {
 	}
 }
 
-func NewPollingResponse(intent fdv2proto.IntentCode, events []fdv2proto.Event, selector fdv2proto.Selector) *PollingResponse {
+func NewPollingResponse(intent fdv2proto.IntentCode, events []fdv2proto.Event, selector *fdv2proto.Selector) *PollingResponse {
 	return &PollingResponse{
 		events:   events,
 		intent:   intent,

internal/datasystem/store.go

@@ -56,7 +56,7 @@ type Store struct {
 	active subsystems.ReadOnlyStore
 
 	// Identifies the current data.
-	selector fdv2proto.Selector
+	selector *fdv2proto.Selector
 
 	mu sync.RWMutex
 
@@ -121,7 +121,7 @@ func (s *Store) WithPersistence(persistent subsystems.DataStore, mode subsystems
 }
 
 // Selector returns the current selector.
-func (s *Store) Selector() fdv2proto.Selector {
+func (s *Store) Selector() *fdv2proto.Selector {
 	s.mu.RLock()
 	defer s.mu.RUnlock()
 	return s.selector
@@ -137,12 +137,12 @@ func (s *Store) Close() error {
 	return nil
 }
 
-func (s *Store) SetBasis(events []fdv2proto.Event, selector fdv2proto.Selector, persist bool) error {
+func (s *Store) SetBasis(events []fdv2proto.Event, selector *fdv2proto.Selector, persist bool) error {
 	collections := fdv2proto.ToStorableItems(events)
 	return s.init(collections, selector, persist)
 }
 
-func (s *Store) init(allData []ldstoretypes.Collection, selector fdv2proto.Selector, persist bool) error {
+func (s *Store) init(allData []ldstoretypes.Collection, selector *fdv2proto.Selector, persist bool) error {
 	s.mu.Lock()
 	defer s.mu.Unlock()
 
@@ -164,7 +164,7 @@ func (s *Store) shouldPersist() bool {
 	return s.persist && s.persistentStore.writable()
 }
 
-func (s *Store) ApplyDelta(events []fdv2proto.Event, selector fdv2proto.Selector, persist bool) error {
+func (s *Store) ApplyDelta(events []fdv2proto.Event, selector *fdv2proto.Selector, persist bool) error {
 	collections := fdv2proto.ToStorableItems(events)
 
 	s.mu.Lock()

internal/datasystem/store_test.go

@@ -44,7 +44,7 @@ func TestStore_NoPersistence_MemoryStore_IsInitialized(t *testing.T) {
 	none := fdv2proto.NoSelector()
 	tests := []struct {
 		name     string
-		selector fdv2proto.Selector
+		selector *fdv2proto.Selector
 		persist  bool
 	}{
 		{"with selector, persist", v1, true},

internal/fdv2proto/selector.go

@@ -3,29 +3,24 @@ package fdv2proto
 type Selector struct {
 	state   string
 	version int
-	set     bool
 }
 
-func NoSelector() Selector {
-	return Selector{set: false}
+func NoSelector() *Selector {
+	return nil
 }
 
-func NewSelector(state string, version int) Selector {
-	return Selector{state: state, version: version, set: true}
+func NewSelector(state string, version int) *Selector {
+	return &Selector{state: state, version: version}
 }
 
-func (s Selector) IsSet() bool {
-	return s.set
+func (s *Selector) IsSet() bool {
+	return s != nil
 }
 
-func (s Selector) State() string {
+func (s *Selector) State() string {
 	return s.state
 }
 
-func (s Selector) Version() int {
+func (s *Selector) Version() int {
 	return s.version
 }
-
-func (s Selector) Get() (string, int, bool) {
-	return s.state, s.version, s.set
-}

internal/sharedtest/mocks/mock_data_destination.go

@@ -42,7 +42,7 @@ func NewMockDataDestination(realStore subsystems.DataStore) *MockDataDestination
 }
 
 // SetBasis in this test implementation, delegates to d.DataStore.CapturedUpdates.
-func (d *MockDataDestination) SetBasis(events []fdv2proto.Event, selector fdv2proto.Selector, persist bool) error {
+func (d *MockDataDestination) SetBasis(events []fdv2proto.Event, _ *fdv2proto.Selector, _ bool) error {
 	// For now, the selector is ignored. When the data sources start making use of it, it should be
 	// stored so that assertions can be made.
 
@@ -54,7 +54,7 @@ func (d *MockDataDestination) SetBasis(events []fdv2proto.Event, selector fdv2pr
 	return d.DataStore.Init(collections)
 }
 
-func (d *MockDataDestination) ApplyDelta(events []fdv2proto.Event, selector fdv2proto.Selector, persist bool) error {
+func (d *MockDataDestination) ApplyDelta(events []fdv2proto.Event, _ *fdv2proto.Selector, _ bool) error {
 	// For now, the selector is ignored. When the data sources start making use of it, it should be
 	// stored so that assertions can be made.
 

subsystems/data_destination.go

@@ -19,7 +19,7 @@ type DataDestination interface {
 	//
 	// If persist is true, it indicates that the data should be propagated to any connected persistent
 	// store.
-	SetBasis(events []fdv2proto.Event, selector fdv2proto.Selector, persist bool) error
+	SetBasis(events []fdv2proto.Event, selector *fdv2proto.Selector, persist bool) error
 
 	// ApplyDelta applies a set of changes to an existing basis. This operation should be atomic with
 	// respect to any other operations that modify the store.
@@ -28,5 +28,5 @@ type DataDestination interface {
 	//
 	// If persist is true, it indicates that the changes should be propagated to any connected persistent
 	// store.
-	ApplyDelta(events []fdv2proto.Event, selector fdv2proto.Selector, persist bool) error
+	ApplyDelta(events []fdv2proto.Event, selector *fdv2proto.Selector, persist bool) error
 }