change xds_cluster_impl to use new LRS API

src/core/load_balancing/xds/xds_cluster_impl.cc

@@ -189,13 +189,13 @@ class XdsClusterImplLb final : public LoadBalancingPolicy {
  private:
   class StatsSubchannelWrapper final : public DelegatingSubchannel {
    public:
-    // If load reporting is enabled and we have an XdsClusterLocalityStats
+    // If load reporting is enabled and we have a ClusterLocalityStats
     // object, that object already contains the locality label.  We
     // need to store the locality label directly only in the case where
     // load reporting is disabled.
     using LocalityData = absl::variant<
         RefCountedStringValue /*locality*/,
-        RefCountedPtr<XdsClusterLocalityStats> /*locality_stats*/>;
+        RefCountedPtr<LrsClient::ClusterLocalityStats> /*locality_stats*/>;
 
     StatsSubchannelWrapper(
         RefCountedPtr<SubchannelInterface> wrapped_subchannel,
@@ -209,18 +209,20 @@ class XdsClusterImplLb final : public LoadBalancingPolicy {
       return Match(
           locality_data_,
           [](RefCountedStringValue locality) { return locality; },
-          [](const RefCountedPtr<XdsClusterLocalityStats>& locality_stats) {
+          [](const RefCountedPtr<LrsClient::ClusterLocalityStats>&
+                 locality_stats) {
             return locality_stats->locality_name()->human_readable_string();
           });
     }
 
-    XdsClusterLocalityStats* locality_stats() const {
+    LrsClient::ClusterLocalityStats* locality_stats() const {
       return Match(
           locality_data_,
           [](const RefCountedStringValue&) {
-            return static_cast<XdsClusterLocalityStats*>(nullptr);
+            return static_cast<LrsClient::ClusterLocalityStats*>(nullptr);
           },
-          [](const RefCountedPtr<XdsClusterLocalityStats>& locality_stats) {
+          [](const RefCountedPtr<LrsClient::ClusterLocalityStats>&
+                 locality_stats) {
             return locality_stats.get();
           });
     }
@@ -250,7 +252,7 @@ class XdsClusterImplLb final : public LoadBalancingPolicy {
     RefCountedStringValue service_telemetry_label_;
     RefCountedStringValue namespace_telemetry_label_;
     RefCountedPtr<XdsEndpointResource::DropConfig> drop_config_;
-    RefCountedPtr<XdsClusterDropStats> drop_stats_;
+    RefCountedPtr<LrsClient::ClusterDropStats> drop_stats_;
     RefCountedPtr<SubchannelPicker> picker_;
   };
 
@@ -304,7 +306,7 @@ class XdsClusterImplLb final : public LoadBalancingPolicy {
   RefCountedPtr<GrpcXdsClient> xds_client_;
 
   // The stats for client-side load reporting.
-  RefCountedPtr<XdsClusterDropStats> drop_stats_;
+  RefCountedPtr<LrsClient::ClusterDropStats> drop_stats_;
 
   OrphanablePtr<LoadBalancingPolicy> child_policy_;
 
@@ -324,7 +326,7 @@ class XdsClusterImplLb::Picker::SubchannelCallTracker final
   SubchannelCallTracker(
       std::unique_ptr<LoadBalancingPolicy::SubchannelCallTrackerInterface>
           original_subchannel_call_tracker,
-      RefCountedPtr<XdsClusterLocalityStats> locality_stats,
+      RefCountedPtr<LrsClient::ClusterLocalityStats> locality_stats,
       RefCountedPtr<CircuitBreakerCallCounterMap::CallCounter> call_counter)
       : original_subchannel_call_tracker_(
             std::move(original_subchannel_call_tracker)),
@@ -380,7 +382,7 @@ class XdsClusterImplLb::Picker::SubchannelCallTracker final
  private:
   std::unique_ptr<LoadBalancingPolicy::SubchannelCallTrackerInterface>
       original_subchannel_call_tracker_;
-  RefCountedPtr<XdsClusterLocalityStats> locality_stats_;
+  RefCountedPtr<LrsClient::ClusterLocalityStats> locality_stats_;
   RefCountedPtr<CircuitBreakerCallCounterMap::CallCounter> call_counter_;
 #ifndef NDEBUG
   bool started_ = false;
@@ -454,7 +456,7 @@ LoadBalancingPolicy::PickResult XdsClusterImplLb::Picker::Pick(
           subchannel_wrapper->locality());
     }
     // Handle load reporting.
-    RefCountedPtr<XdsClusterLocalityStats> locality_stats;
+    RefCountedPtr<LrsClient::ClusterLocalityStats> locality_stats;
     if (subchannel_wrapper->locality_stats() != nullptr) {
       locality_stats = subchannel_wrapper->locality_stats()->Ref(
           DEBUG_LOCATION, "SubchannelCallTracker");
@@ -624,7 +626,7 @@ absl::Status XdsClusterImplLb::UpdateLocked(UpdateArgs args) {
              old_eds_service_name != new_eds_service_name ||
              cluster_resource_->lrs_load_reporting_server !=
                  new_cluster_config.cluster->lrs_load_reporting_server) {
-    drop_stats_ = xds_client_->AddClusterDropStats(
+    drop_stats_ = xds_client_->lrs_client().AddClusterDropStats(
         *new_cluster_config.cluster->lrs_load_reporting_server,
         new_config->cluster_name(), new_eds_service_name);
     if (drop_stats_ == nullptr) {
@@ -819,9 +821,10 @@ RefCountedPtr<SubchannelInterface> XdsClusterImplLb::Helper::CreateSubchannel(
   // (if load reporting is enabled) the locality stats object, which
   // will be used by the picker.
   auto locality_name = per_address_args.GetObjectRef<XdsLocalityName>();
-  RefCountedPtr<XdsClusterLocalityStats> locality_stats;
+  RefCountedPtr<LrsClient::ClusterLocalityStats> locality_stats;
   if (parent()->cluster_resource_->lrs_load_reporting_server.has_value()) {
-    locality_stats = parent()->xds_client_->AddClusterLocalityStats(
+    locality_stats =
+        parent()->xds_client_->lrs_client().AddClusterLocalityStats(
             parent()->cluster_resource_->lrs_load_reporting_server.value(),
             parent()->config_->cluster_name(),
             GetEdsResourceName(*parent()->cluster_resource_), locality_name);

src/core/xds/grpc/xds_client_grpc.cc

@@ -338,6 +338,11 @@ void GrpcXdsClient::Orphaned() {
   }
 }
 
+void GrpcXdsClient::ResetBackoff() {
+  XdsClient::ResetBackoff();
+  lrs_client_->ResetBackoff();
+}
+
 grpc_pollset_set* GrpcXdsClient::interested_parties() const {
   return reinterpret_cast<GrpcXdsTransportFactory*>(transport_factory())
       ->interested_parties();

src/core/xds/grpc/xds_client_grpc.h

@@ -74,6 +74,8 @@ class GrpcXdsClient final : public XdsClient {
     return QsortCompare(a, b);
   }
 
+  void ResetBackoff() override;
+
   grpc_pollset_set* interested_parties() const;
 
   CertificateProviderStore& certificate_provider_store() const {
@@ -82,7 +84,7 @@ class GrpcXdsClient final : public XdsClient {
 
   absl::string_view key() const { return key_; }
 
-  RefCountedPtr<LrsClient> lrs_client() const { return lrs_client_; }
+  LrsClient& lrs_client() { return *lrs_client_; }
 
   // Builds ClientStatusResponse containing all resources from all XdsClients
   static grpc_slice DumpAllClientConfigs();

src/core/xds/xds_client/xds_client.h

@@ -148,7 +148,7 @@ class XdsClient : public DualRefCounted<XdsClient> {
       XdsClusterLocalityStats* cluster_locality_stats);
 
   // Resets connection backoff state.
-  void ResetBackoff();
+  virtual void ResetBackoff();
 
   grpc_event_engine::experimental::EventEngine* engine() {
     return engine_.get();