GODRIVER-2572 Clean up code per review

mongo/collection.go

@@ -1870,49 +1870,47 @@ func (coll *Collection) drop(ctx context.Context) error {
 
 type pinnedServerSelector struct {
 	stringer fmt.Stringer
-	fn       description.ServerSelectorFunc
+	fallback description.ServerSelector
+	session  *session.Client
 }
 
 func (pss pinnedServerSelector) String() string {
+	if pss.stringer == nil {
+		return ""
+	}
+
 	return pss.stringer.String()
 }
 
 func (pss pinnedServerSelector) SelectServer(
 	t description.Topology,
-	s []description.Server,
+	svrs []description.Server,
 ) ([]description.Server, error) {
-	return pss.fn(t, s)
-}
-
-// pinnedSelectorFunc makes a selector for a pinned session with a pinned
-// server. It attempts to do server selection on the pinned server, but if that
-// fails, it will go through a list of default selectors.
-func pinnedSelectorFunc(sess *session.Client, defaultSelector description.ServerSelector) description.ServerSelectorFunc {
-	return func(t description.Topology, svrs []description.Server) ([]description.Server, error) {
-		if sess != nil && sess.PinnedServer != nil {
-			// If there is a pinned server, try to find it in the list of candidates.
-			for _, candidate := range svrs {
-				if candidate.Addr == sess.PinnedServer.Addr {
-					return []description.Server{candidate}, nil
-				}
+	if pss.session != nil && pss.session.PinnedServer != nil {
+		// If there is a pinned server, try to find it in the list of candidates.
+		for _, candidate := range svrs {
+			if candidate.Addr == pss.session.PinnedServer.Addr {
+				return []description.Server{candidate}, nil
 			}
-
-			return nil, nil
 		}
 
-		return defaultSelector.SelectServer(t, svrs)
+		return nil, nil
 	}
+
+	return pss.fallback.SelectServer(t, svrs)
 }
 
-func makePinnedSelector(sess *session.Client, defaultSelector description.ServerSelector) description.ServerSelector {
-	if srvSelectorStringer, ok := defaultSelector.(fmt.Stringer); ok {
-		return pinnedServerSelector{
-			stringer: srvSelectorStringer,
-			fn:       pinnedSelectorFunc(sess, defaultSelector),
-		}
+func makePinnedSelector(sess *session.Client, fallback description.ServerSelector) description.ServerSelector {
+	pss := pinnedServerSelector{
+		session:  sess,
+		fallback: fallback,
+	}
+
+	if srvSelectorStringer, ok := fallback.(fmt.Stringer); ok {
+		pss.stringer = srvSelectorStringer
 	}
 
-	return pinnedSelectorFunc(sess, defaultSelector)
+	return pss
 }
 
 func makeReadPrefSelector(sess *session.Client, selector description.ServerSelector, localThreshold time.Duration) description.ServerSelector {

mongo/description/server_selector.go

@@ -57,15 +57,15 @@ type compositeSelector struct {
 }
 
 func (cs *compositeSelector) info() serverSelectorInfo {
-	cssInfo := &serverSelectorInfo{Type: "compositeSelector"}
+	csInfo := serverSelectorInfo{Type: "compositeSelector"}
 
 	for _, sel := range cs.selectors {
 		if getter, ok := sel.(serverSelectorInfoGetter); ok {
-			cssInfo.Selectors = append(cssInfo.Selectors, getter.info())
+			csInfo.Selectors = append(csInfo.Selectors, getter.info())
 		}
 	}
 
-	return *cssInfo
+	return csInfo
 }
 
 // String returns the JSON string representation of the compositeSelector.
@@ -204,7 +204,6 @@ func ReadPrefSelector(rp *readpref.ReadPref) ServerSelector {
 		rp:                rp,
 		isOutputAggregate: false,
 	}
-
 }
 
 func (selector readPrefServerSelector) info() serverSelectorInfo {

mongo/integration/unified/client_entity.go

@@ -62,7 +62,7 @@ type clientEntity struct {
 	observedEvents                      map[monitoringEventType]struct{}
 	storedEvents                        map[monitoringEventType][]string
 	eventsCount                         map[monitoringEventType]int32
-	serverDescriptionChangedEventsCount map[serverDescriptionChangedEvent]int32
+	serverDescriptionChangedEventsCount map[serverDescriptionChangedEventInfo]int32
 
 	eventsCountLock                         sync.RWMutex
 	serverDescriptionChangedEventsCountLock sync.RWMutex
@@ -89,7 +89,7 @@ func newClientEntity(ctx context.Context, em *EntityMap, entityOptions *entityOp
 		observedEvents:                      make(map[monitoringEventType]struct{}),
 		storedEvents:                        make(map[monitoringEventType][]string),
 		eventsCount:                         make(map[monitoringEventType]int32),
-		serverDescriptionChangedEventsCount: make(map[serverDescriptionChangedEvent]int32),
+		serverDescriptionChangedEventsCount: make(map[serverDescriptionChangedEventInfo]int32),
 		entityMap:                           em,
 		observeSensitiveCommands:            entityOptions.ObserveSensitiveCommands,
 	}
@@ -302,7 +302,7 @@ func (c *clientEntity) addEventsCount(eventType monitoringEventType) {
 	c.eventsCount[eventType]++
 }
 
-func (c *clientEntity) addServerDescriptionChangedEventCount(evt serverDescriptionChangedEvent) {
+func (c *clientEntity) addServerDescriptionChangedEventCount(evt serverDescriptionChangedEventInfo) {
 	c.serverDescriptionChangedEventsCountLock.Lock()
 	defer c.serverDescriptionChangedEventsCountLock.Unlock()
 
@@ -316,7 +316,7 @@ func (c *clientEntity) getEventCount(eventType monitoringEventType) int32 {
 	return c.eventsCount[eventType]
 }
 
-func (c *clientEntity) getServerDescriptionChangedEventCount(evt serverDescriptionChangedEvent) int32 {
+func (c *clientEntity) getServerDescriptionChangedEventCount(evt serverDescriptionChangedEventInfo) int32 {
 	c.serverDescriptionChangedEventsCountLock.Lock()
 	defer c.serverDescriptionChangedEventsCountLock.Unlock()
 
@@ -475,15 +475,15 @@ func (c *clientEntity) processServerDescriptionChangedEvent(evt *event.ServerDes
 		return
 	}
 
-	if _, ok := c.observedEvents[serverDescriptionChangedInfo]; ok {
+	if _, ok := c.observedEvents[serverDescriptionChangedEvent]; ok {
 		c.serverDescriptionChanged = append(c.serverDescriptionChanged, evt)
 	}
 
 	// Record object-specific unified spec test data on an event.
-	c.addServerDescriptionChangedEventCount(*newServerDescriptionChangedEvent(evt))
+	c.addServerDescriptionChangedEventCount(*newServerDescriptionChangedEventInfo(evt))
 
 	// Record the event generally.
-	c.addEventsCount(serverDescriptionChangedInfo)
+	c.addEventsCount(serverDescriptionChangedEvent)
 }
 
 func (c *clientEntity) processServerHeartbeatFailedEvent(evt *event.ServerHeartbeatFailedEvent) {

mongo/integration/unified/event.go

@@ -31,7 +31,7 @@ const (
 	connectionCheckOutFailedEvent   monitoringEventType = "ConnectionCheckOutFailedEvent"
 	connectionCheckedOutEvent       monitoringEventType = "ConnectionCheckedOutEvent"
 	connectionCheckedInEvent        monitoringEventType = "ConnectionCheckedInEvent"
-	serverDescriptionChangedInfo    monitoringEventType = "ServerDescriptionChangedEvent"
+	serverDescriptionChangedEvent   monitoringEventType = "ServerDescriptionChangedEvent"
 	serverHeartbeatFailedEvent      monitoringEventType = "ServerHeartbeatFailedEvent"
 	serverHeartbeatStartedEvent     monitoringEventType = "ServerHeartbeatStartedEvent"
 	serverHeartbeatSucceededEvent   monitoringEventType = "ServerHeartbeatSucceededEvent"
@@ -69,7 +69,7 @@ func monitoringEventTypeFromString(eventStr string) (monitoringEventType, bool)
 	case "connectioncheckedinevent":
 		return connectionCheckedInEvent, true
 	case "serverdescriptionchangedevent":
-		return serverDescriptionChangedInfo, true
+		return serverDescriptionChangedEvent, true
 	case "serverheartbeatfailedevent":
 		return serverHeartbeatFailedEvent, true
 	case "serverheartbeatstartedevent":
@@ -119,9 +119,9 @@ type serverDescription struct {
 	Type string
 }
 
-// serverDescriptionChangedEvent represents an event generated when the server
+// serverDescriptionChangedEventInfo represents an event generated when the server
 // description changes.
-type serverDescriptionChangedEvent struct {
+type serverDescriptionChangedEventInfo struct {
 	// NewDescription  corresponds to the server description as it was after
 	// the change that triggered this event.
 	NewDescription serverDescription
@@ -131,10 +131,10 @@ type serverDescriptionChangedEvent struct {
 	PreviousDescription serverDescription
 }
 
-// newServerDescriptionChangedEvent returns a new serverDescriptionChangedEvent
+// newServerDescriptionChangedEventInfo returns a new serverDescriptionChangedEvent
 // instance for the given event.
-func newServerDescriptionChangedEvent(evt *event.ServerDescriptionChangedEvent) *serverDescriptionChangedEvent {
-	return &serverDescriptionChangedEvent{
+func newServerDescriptionChangedEventInfo(evt *event.ServerDescriptionChangedEvent) *serverDescriptionChangedEventInfo {
+	return &serverDescriptionChangedEventInfo{
 		NewDescription: serverDescription{
 			Type: evt.NewDescription.Kind.String(),
 		},
@@ -146,7 +146,7 @@ func newServerDescriptionChangedEvent(evt *event.ServerDescriptionChangedEvent)
 
 // UnmarshalBSON unmarshals the event from BSON, used when trying to create the
 // expected event from a unified spec test.
-func (evt *serverDescriptionChangedEvent) UnmarshalBSON(data []byte) error {
+func (evt *serverDescriptionChangedEventInfo) UnmarshalBSON(data []byte) error {
 	if len(data) == 0 {
 		return nil
 	}

mongo/integration/unified/testrunner_operation.go

@@ -302,10 +302,10 @@ func getServerDescriptionChangedEventCount(client *clientEntity, raw bson.Raw) i
 	// If the document has no values, then we assume that the UST only
 	// intends to check that the event happened.
 	if values, _ := raw.Values(); len(values) == 0 {
-		return client.getEventCount(serverDescriptionChangedInfo)
+		return client.getEventCount(serverDescriptionChangedEvent)
 	}
 
-	var expectedEvt serverDescriptionChangedEvent
+	var expectedEvt serverDescriptionChangedEventInfo
 	if err := bson.Unmarshal(raw, &expectedEvt); err != nil {
 		return 0
 	}
@@ -323,7 +323,7 @@ func (args waitForEventArguments) eventCompleted(client *clientEntity) bool {
 		}
 
 		switch eventType {
-		case serverDescriptionChangedInfo:
+		case serverDescriptionChangedEvent:
 			if getServerDescriptionChangedEventCount(client, eventDoc) < args.Count {
 				return false
 			}