Cache EndpointSlices directly rather than copying the data

Given that we are no longer modifying any of the EndpointSlice data,
we can just work with pointers to the actual EndpointSlice objects.
(The informer cache is already holding on to them, so they'll be
taking up memory whether or not the EndpointSliceCache points to
them.)

pkg/proxy/endpointslicecache.go

@@ -65,26 +65,10 @@ type endpointSliceTracker struct {
 // corresponding EndpointSlices.
 type endpointSliceDataByName map[string]*endpointSliceData
 
-// endpointSliceData contains just the attributes kube-proxy cares about.
+// endpointSliceData contains information about a single EndpointSlice update or removal.
-// Used for caching. Intentionally small to limit memory util.
 type endpointSliceData struct {
-	Ports     []discovery.EndpointPort
+	endpointSlice *discovery.EndpointSlice
-	Endpoints []*endpointData
+	remove        bool
-	Remove    bool
-}
-
-// endpointData contains just the attributes kube-proxy cares about.
-// Used for caching. Intentionally small to limit memory util.
-// Addresses, NodeName, and Zone are copied from EndpointSlice Endpoints.
-type endpointData struct {
-	Addresses []string
-	NodeName  *string
-	Zone      *string
-	ZoneHints sets.Set[string]
-
-	Ready       bool
-	Serving     bool
-	Terminating bool
 }
 
 // NewEndpointSliceCache initializes an EndpointSliceCache.
@@ -109,43 +93,6 @@ func newEndpointSliceTracker() *endpointSliceTracker {
 	}
 }
 
-// newEndpointSliceData generates endpointSliceData from an EndpointSlice.
-func newEndpointSliceData(endpointSlice *discovery.EndpointSlice, remove bool) *endpointSliceData {
-	esData := &endpointSliceData{
-		Ports:     endpointSlice.Ports,
-		Endpoints: []*endpointData{},
-		Remove:    remove,
-	}
-
-	if !remove {
-		for _, endpoint := range endpointSlice.Endpoints {
-			epData := &endpointData{
-				Addresses: endpoint.Addresses,
-				Zone:      endpoint.Zone,
-				NodeName:  endpoint.NodeName,
-
-				// conditions
-				Ready:       endpoint.Conditions.Ready == nil || *endpoint.Conditions.Ready,
-				Serving:     endpoint.Conditions.Serving == nil || *endpoint.Conditions.Serving,
-				Terminating: endpoint.Conditions.Terminating != nil && *endpoint.Conditions.Terminating,
-			}
-
-			if utilfeature.DefaultFeatureGate.Enabled(features.TopologyAwareHints) {
-				if endpoint.Hints != nil && len(endpoint.Hints.ForZones) > 0 {
-					epData.ZoneHints = sets.New[string]()
-					for _, zone := range endpoint.Hints.ForZones {
-						epData.ZoneHints.Insert(zone.Name)
-					}
-				}
-			}
-
-			esData.Endpoints = append(esData.Endpoints, epData)
-		}
-	}
-
-	return esData
-}
-
 // standardEndpointInfo is the default makeEndpointFunc.
 func standardEndpointInfo(ep *BaseEndpointInfo, _ *ServicePortName) Endpoint {
 	return ep
@@ -159,7 +106,7 @@ func (cache *EndpointSliceCache) updatePending(endpointSlice *discovery.Endpoint
 		return false
 	}
 
-	esData := newEndpointSliceData(endpointSlice, remove)
+	esData := &endpointSliceData{endpointSlice, remove}
 
 	cache.lock.Lock()
 	defer cache.lock.Unlock()
@@ -195,7 +142,7 @@ func (cache *EndpointSliceCache) checkoutChanges() map[types.NamespacedName]*end
 		change.previous = cache.getEndpointsMap(serviceNN, esTracker.applied)
 
 		for name, sliceData := range esTracker.pending {
-			if sliceData.Remove {
+			if sliceData.remove {
 				delete(esTracker.applied, name)
 			} else {
 				esTracker.applied[name] = sliceData
@@ -226,7 +173,7 @@ func (cache *EndpointSliceCache) endpointInfoByServicePort(serviceNN types.Names
 	endpointInfoBySP := spToEndpointMap{}
 
 	for _, sliceData := range sliceDataByName {
-		for _, port := range sliceData.Ports {
+		for _, port := range sliceData.endpointSlice.Ports {
 			if port.Name == nil {
 				klog.ErrorS(nil, "Ignoring port with nil name", "portName", port.Name)
 				continue
@@ -243,15 +190,15 @@ func (cache *EndpointSliceCache) endpointInfoByServicePort(serviceNN types.Names
 				Protocol:       *port.Protocol,
 			}
 
-			endpointInfoBySP[svcPortName] = cache.addEndpoints(&svcPortName, int(*port.Port), endpointInfoBySP[svcPortName], sliceData.Endpoints)
+			endpointInfoBySP[svcPortName] = cache.addEndpoints(&svcPortName, int(*port.Port), endpointInfoBySP[svcPortName], sliceData.endpointSlice.Endpoints)
 		}
 	}
 
 	return endpointInfoBySP
 }
 
-// addEndpoints adds endpointInfo for each unique endpoint.
+// addEndpoints adds an Endpoint for each unique endpoint.
-func (cache *EndpointSliceCache) addEndpoints(svcPortName *ServicePortName, portNum int, endpointSet map[string]Endpoint, endpoints []*endpointData) map[string]Endpoint {
+func (cache *EndpointSliceCache) addEndpoints(svcPortName *ServicePortName, portNum int, endpointSet map[string]Endpoint, endpoints []discovery.Endpoint) map[string]Endpoint {
 	if endpointSet == nil {
 		endpointSet = map[string]Endpoint{}
 	}
@@ -274,8 +221,22 @@ func (cache *EndpointSliceCache) addEndpoints(svcPortName *ServicePortName, port
 
 		isLocal := endpoint.NodeName != nil && cache.isLocal(*endpoint.NodeName)
 
+		ready := endpoint.Conditions.Ready == nil || *endpoint.Conditions.Ready
+		serving := endpoint.Conditions.Serving == nil || *endpoint.Conditions.Serving
+		terminating := endpoint.Conditions.Terminating != nil && *endpoint.Conditions.Terminating
+
+		var zoneHints sets.Set[string]
+		if utilfeature.DefaultFeatureGate.Enabled(features.TopologyAwareHints) {
+			if endpoint.Hints != nil && len(endpoint.Hints.ForZones) > 0 {
+				zoneHints = sets.New[string]()
+				for _, zone := range endpoint.Hints.ForZones {
+					zoneHints.Insert(zone.Name)
+				}
+			}
+		}
+
 		endpointInfo := newBaseEndpointInfo(endpoint.Addresses[0], portNum, isLocal,
-			endpoint.Ready, endpoint.Serving, endpoint.Terminating, endpoint.ZoneHints)
+			ready, serving, terminating, zoneHints)
 
 		// This logic ensures we're deduplicating potential overlapping endpoints
 		// isLocal should not vary between matching endpoints, but if it does, we
@@ -314,7 +275,7 @@ func (cache *EndpointSliceCache) esDataChanged(serviceKey types.NamespacedName,
 
 	// If this is marked for removal and does not exist in the cache, no changes
 	// are necessary.
-	if esData.Remove {
+	if esData.remove {
 		return false
 	}
 

pkg/proxy/endpointslicecache_test.go

@@ -454,7 +454,7 @@ func TestEsDataChanged(t *testing.T) {
 				t.Fatalf("Expected no error calling endpointSliceCacheKeys(): %v", err)
 			}
 
-			esData := newEndpointSliceData(tc.updatedSlice, false)
+			esData := &endpointSliceData{tc.updatedSlice, false}
 			changed := tc.cache.esDataChanged(serviceKey, sliceKey, esData)
 
 			if tc.expectChanged != changed {