xds_override_host LB: move XdsOverrideHostLbConfig to `internal` namespace (#32061)

build_autogenerated.yaml

@@ -353,6 +353,7 @@ libs:
   - src/core/ext/filters/client_channel/lb_policy/subchannel_list.h
   - src/core/ext/filters/client_channel/lb_policy/xds/xds_attributes.h
   - src/core/ext/filters/client_channel/lb_policy/xds/xds_channel_args.h
+  - src/core/ext/filters/client_channel/lb_policy/xds/xds_override_host.h
   - src/core/ext/filters/client_channel/local_subchannel_pool.h
   - src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.h
   - src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h

gRPC-C++.podspec

@@ -265,6 +265,7 @@ Pod::Spec.new do |s|
                       'src/core/ext/filters/client_channel/lb_policy/subchannel_list.h',
                       'src/core/ext/filters/client_channel/lb_policy/xds/xds_attributes.h',
                       'src/core/ext/filters/client_channel/lb_policy/xds/xds_channel_args.h',
+                      'src/core/ext/filters/client_channel/lb_policy/xds/xds_override_host.h',
                       'src/core/ext/filters/client_channel/local_subchannel_pool.h',
                       'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.h',
                       'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h',
@@ -1194,6 +1195,7 @@ Pod::Spec.new do |s|
                               'src/core/ext/filters/client_channel/lb_policy/subchannel_list.h',
                               'src/core/ext/filters/client_channel/lb_policy/xds/xds_attributes.h',
                               'src/core/ext/filters/client_channel/lb_policy/xds/xds_channel_args.h',
+                              'src/core/ext/filters/client_channel/lb_policy/xds/xds_override_host.h',
                               'src/core/ext/filters/client_channel/local_subchannel_pool.h',
                               'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.h',
                               'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h',

gRPC-Core.podspec

@@ -270,6 +270,7 @@ Pod::Spec.new do |s|
                       'src/core/ext/filters/client_channel/lb_policy/xds/xds_cluster_manager.cc',
                       'src/core/ext/filters/client_channel/lb_policy/xds/xds_cluster_resolver.cc',
                       'src/core/ext/filters/client_channel/lb_policy/xds/xds_override_host.cc',
+                      'src/core/ext/filters/client_channel/lb_policy/xds/xds_override_host.h',
                       'src/core/ext/filters/client_channel/lb_policy/xds/xds_wrr_locality.cc',
                       'src/core/ext/filters/client_channel/local_subchannel_pool.cc',
                       'src/core/ext/filters/client_channel/local_subchannel_pool.h',
@@ -1883,6 +1884,7 @@ Pod::Spec.new do |s|
                               'src/core/ext/filters/client_channel/lb_policy/subchannel_list.h',
                               'src/core/ext/filters/client_channel/lb_policy/xds/xds_attributes.h',
                               'src/core/ext/filters/client_channel/lb_policy/xds/xds_channel_args.h',
+                              'src/core/ext/filters/client_channel/lb_policy/xds/xds_override_host.h',
                               'src/core/ext/filters/client_channel/local_subchannel_pool.h',
                               'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.h',
                               'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h',

grpc.gemspec

@@ -181,6 +181,7 @@ Gem::Specification.new do |s|
   s.files += %w( src/core/ext/filters/client_channel/lb_policy/xds/xds_cluster_manager.cc )
   s.files += %w( src/core/ext/filters/client_channel/lb_policy/xds/xds_cluster_resolver.cc )
   s.files += %w( src/core/ext/filters/client_channel/lb_policy/xds/xds_override_host.cc )
+  s.files += %w( src/core/ext/filters/client_channel/lb_policy/xds/xds_override_host.h )
   s.files += %w( src/core/ext/filters/client_channel/lb_policy/xds/xds_wrr_locality.cc )
   s.files += %w( src/core/ext/filters/client_channel/local_subchannel_pool.cc )
   s.files += %w( src/core/ext/filters/client_channel/local_subchannel_pool.h )

package.xml

@@ -163,6 +163,7 @@
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/lb_policy/xds/xds_cluster_manager.cc" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/lb_policy/xds/xds_cluster_resolver.cc" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/lb_policy/xds/xds_override_host.cc" role="src" />
+    <file baseinstalldir="/" name="src/core/ext/filters/client_channel/lb_policy/xds/xds_override_host.h" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/lb_policy/xds/xds_wrr_locality.cc" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/local_subchannel_pool.cc" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/local_subchannel_pool.h" role="src" />

src/core/BUILD

@@ -4444,6 +4444,9 @@ grpc_cc_library(
     srcs = [
         "ext/filters/client_channel/lb_policy/xds/xds_override_host.cc",
     ],
+    hdrs = [
+        "ext/filters/client_channel/lb_policy/xds/xds_override_host.h",
+    ],
     external_deps = [
         "absl/base:core_headers",
         "absl/status",

src/core/ext/filters/client_channel/lb_policy/xds/xds_override_host.cc

@@ -16,6 +16,8 @@
 
 #include <grpc/support/port_platform.h>
 
+#include "src/core/ext/filters/client_channel/lb_policy/xds/xds_override_host.h"
+
 #include <atomic>
 #include <functional>
 #include <map>
@@ -72,40 +74,13 @@ namespace {
 //
 // xds_override_host LB policy
 //
-
-constexpr absl::string_view kXdsOverrideHost = "xds_override_host_experimental";
-
-// Config for stateful session LB policy.
-class XdsOverrideHostLbConfig : public LoadBalancingPolicy::Config {
- public:
-  XdsOverrideHostLbConfig() = default;
-
-  XdsOverrideHostLbConfig(const XdsOverrideHostLbConfig&) = delete;
-  XdsOverrideHostLbConfig& operator=(const XdsOverrideHostLbConfig&) = delete;
-
-  XdsOverrideHostLbConfig(XdsOverrideHostLbConfig&& other) = delete;
-  XdsOverrideHostLbConfig& operator=(XdsOverrideHostLbConfig&& other) = delete;
-
-  absl::string_view name() const override { return kXdsOverrideHost; }
-
-  RefCountedPtr<LoadBalancingPolicy::Config> child_config() const {
-    return child_config_;
-  }
-
-  static const JsonLoaderInterface* JsonLoader(const JsonArgs&);
-  void JsonPostLoad(const Json& json, const JsonArgs&,
-                    ValidationErrors* errors);
-
- private:
-  RefCountedPtr<LoadBalancingPolicy::Config> child_config_;
-};
-
-// xDS Cluster Impl LB policy.
 class XdsOverrideHostLb : public LoadBalancingPolicy {
  public:
   explicit XdsOverrideHostLb(Args args);
 
-  absl::string_view name() const override { return kXdsOverrideHost; }
+  absl::string_view name() const override {
+    return XdsOverrideHostLbConfig::Name();
+  }
 
   absl::Status UpdateLocked(UpdateArgs args) override;
   void ExitIdleLocked() override;
@@ -610,33 +585,6 @@ void XdsOverrideHostLb::SubchannelWrapper::CancelConnectivityStateWatch(
 //
 // factory
 //
-const JsonLoaderInterface* XdsOverrideHostLbConfig::JsonLoader(
-    const JsonArgs&) {
-  static const auto kJsonLoader =
-      JsonObjectLoader<XdsOverrideHostLbConfig>()
-          // Child policy config is parsed in JsonPostLoad
-          .Finish();
-  return kJsonLoader;
-}
-
-void XdsOverrideHostLbConfig::JsonPostLoad(const Json& json, const JsonArgs&,
-                                           ValidationErrors* errors) {
-  ValidationErrors::ScopedField field(errors, ".childPolicy");
-  auto it = json.object_value().find("childPolicy");
-  if (it == json.object_value().end()) {
-    errors->AddError("field not present");
-  } else {
-    auto child_policy_config =
-        CoreConfiguration::Get().lb_policy_registry().ParseLoadBalancingConfig(
-            it->second);
-    if (!child_policy_config.ok()) {
-      errors->AddError(child_policy_config.status().message());
-    } else {
-      child_config_ = std::move(*child_policy_config);
-    }
-  }
-}
-
 class XdsOverrideHostLbFactory : public LoadBalancingPolicyFactory {
  public:
   OrphanablePtr<LoadBalancingPolicy> CreateLoadBalancingPolicy(
@@ -644,7 +592,9 @@ class XdsOverrideHostLbFactory : public LoadBalancingPolicyFactory {
     return MakeOrphanable<XdsOverrideHostLb>(std::move(args));
   }
 
-  absl::string_view name() const override { return kXdsOverrideHost; }
+  absl::string_view name() const override {
+    return XdsOverrideHostLbConfig::Name();
+  }
 
   absl::StatusOr<RefCountedPtr<LoadBalancingPolicy::Config>>
   ParseLoadBalancingConfig(const Json& json) const override {
@@ -668,4 +618,34 @@ void RegisterXdsOverrideHostLbPolicy(CoreConfiguration::Builder* builder) {
   builder->lb_policy_registry()->RegisterLoadBalancingPolicyFactory(
       std::make_unique<XdsOverrideHostLbFactory>());
 }
+
+// XdsOverrideHostLbConfig
+
+const JsonLoaderInterface* XdsOverrideHostLbConfig::JsonLoader(
+    const JsonArgs&) {
+  static const auto kJsonLoader =
+      JsonObjectLoader<XdsOverrideHostLbConfig>()
+          // Child policy config is parsed in JsonPostLoad
+          .Finish();
+  return kJsonLoader;
+}
+
+void XdsOverrideHostLbConfig::JsonPostLoad(const Json& json, const JsonArgs&,
+                                           ValidationErrors* errors) {
+  ValidationErrors::ScopedField field(errors, ".childPolicy");
+  auto it = json.object_value().find("childPolicy");
+  if (it == json.object_value().end()) {
+    errors->AddError("field not present");
+  } else {
+    auto child_policy_config =
+        CoreConfiguration::Get().lb_policy_registry().ParseLoadBalancingConfig(
+            it->second);
+    if (!child_policy_config.ok()) {
+      errors->AddError(child_policy_config.status().message());
+    } else {
+      child_config_ = std::move(*child_policy_config);
+    }
+  }
+}
+
 }  // namespace grpc_core

src/core/ext/filters/client_channel/lb_policy/xds/xds_override_host.h

@@ -0,0 +1,60 @@
+//
+// Copyright 2023 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+#ifndef GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_XDS_XDS_OVERRIDE_HOST_H
+#define GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_XDS_XDS_OVERRIDE_HOST_H
+
+#include <grpc/support/port_platform.h>
+
+#include "absl/strings/string_view.h"
+
+#include "src/core/lib/gprpp/ref_counted_ptr.h"
+#include "src/core/lib/gprpp/validation_errors.h"
+#include "src/core/lib/json/json.h"
+#include "src/core/lib/json/json_args.h"
+#include "src/core/lib/json/json_object_loader.h"
+#include "src/core/lib/load_balancing/lb_policy.h"
+
+namespace grpc_core {
+
+// Config for stateful session LB policy.
+class XdsOverrideHostLbConfig : public LoadBalancingPolicy::Config {
+ public:
+  XdsOverrideHostLbConfig() = default;
+
+  XdsOverrideHostLbConfig(const XdsOverrideHostLbConfig&) = delete;
+  XdsOverrideHostLbConfig& operator=(const XdsOverrideHostLbConfig&) = delete;
+
+  XdsOverrideHostLbConfig(XdsOverrideHostLbConfig&& other) = delete;
+  XdsOverrideHostLbConfig& operator=(XdsOverrideHostLbConfig&& other) = delete;
+
+  static absl::string_view Name() { return "xds_override_host_experimental"; }
+
+  absl::string_view name() const override { return Name(); }
+
+  RefCountedPtr<LoadBalancingPolicy::Config> child_config() const {
+    return child_config_;
+  }
+
+  static const JsonLoaderInterface* JsonLoader(const JsonArgs&);
+  void JsonPostLoad(const Json& json, const JsonArgs&,
+                    ValidationErrors* errors);
+
+ private:
+  RefCountedPtr<LoadBalancingPolicy::Config> child_config_;
+};
+}  // namespace grpc_core
+#endif  // GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_XDS_XDS_OVERRIDE_HOST_H

test/core/client_channel/lb_policy/xds_override_host_lb_config_parser_test.cc

@@ -20,6 +20,8 @@
 
 #include <grpc/grpc.h>
 
+#include "src/core/ext/filters/client_channel/client_channel_service_config.h"
+#include "src/core/ext/filters/client_channel/lb_policy/xds/xds_override_host.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/gprpp/ref_counted_ptr.h"
 #include "src/core/lib/service_config/service_config.h"
@@ -30,6 +32,9 @@ namespace grpc_core {
 namespace testing {
 namespace {
 
+using internal::ClientChannelGlobalParsedConfig;
+using internal::ClientChannelServiceConfigParser;
+
 TEST(XdsOverrideHostConfigParsingTest, ValidConfig) {
   const char* service_config_json =
       "{\n"
@@ -45,6 +50,47 @@ TEST(XdsOverrideHostConfigParsingTest, ValidConfig) {
       ServiceConfigImpl::Create(ChannelArgs(), service_config_json);
   ASSERT_TRUE(service_config.ok());
   EXPECT_NE(*service_config, nullptr);
+  auto global_config = static_cast<ClientChannelGlobalParsedConfig*>(
+      (*service_config)
+          ->GetGlobalParsedConfig(
+              ClientChannelServiceConfigParser::ParserIndex()));
+  ASSERT_NE(global_config, nullptr);
+  auto lb_config = global_config->parsed_lb_config();
+  ASSERT_NE(lb_config, nullptr);
+  ASSERT_EQ(lb_config->name(), XdsOverrideHostLbConfig::Name());
+  auto override_host_lb_config =
+      static_cast<RefCountedPtr<XdsOverrideHostLbConfig>>(lb_config);
+  ASSERT_NE(override_host_lb_config->child_config(), nullptr);
+  ASSERT_EQ(override_host_lb_config->child_config()->name(), "grpclb");
+}
+
+TEST(XdsOverrideHostConfigParsingTest, ValidConfigWithRR) {
+  const char* service_config_json =
+      "{\n"
+      "  \"loadBalancingConfig\":[{\n"
+      "    \"xds_override_host_experimental\":{\n"
+      "      \"childPolicy\":[\n"
+      "        {\"round_robin\":{}}\n"
+      "      ]\n"
+      "    }\n"
+      "  }]\n"
+      "}\n";
+  auto service_config =
+      ServiceConfigImpl::Create(ChannelArgs(), service_config_json);
+  ASSERT_TRUE(service_config.ok());
+  EXPECT_NE(*service_config, nullptr);
+  auto global_config = static_cast<ClientChannelGlobalParsedConfig*>(
+      (*service_config)
+          ->GetGlobalParsedConfig(
+              ClientChannelServiceConfigParser::ParserIndex()));
+  ASSERT_NE(global_config, nullptr);
+  auto lb_config = global_config->parsed_lb_config();
+  ASSERT_NE(lb_config, nullptr);
+  ASSERT_EQ(lb_config->name(), XdsOverrideHostLbConfig::Name());
+  auto override_host_lb_config =
+      static_cast<RefCountedPtr<XdsOverrideHostLbConfig>>(lb_config);
+  ASSERT_NE(override_host_lb_config->child_config(), nullptr);
+  ASSERT_EQ(override_host_lb_config->child_config()->name(), "round_robin");
 }
 
 TEST(XdsOverrideHostConfigParsingTest, ReportsMissingChildPolicyField) {

tools/doxygen/Doxyfile.c++.internal

@@ -1137,6 +1137,7 @@ src/core/ext/filters/client_channel/lb_policy/xds/xds_cluster_impl.cc \
 src/core/ext/filters/client_channel/lb_policy/xds/xds_cluster_manager.cc \
 src/core/ext/filters/client_channel/lb_policy/xds/xds_cluster_resolver.cc \
 src/core/ext/filters/client_channel/lb_policy/xds/xds_override_host.cc \
+src/core/ext/filters/client_channel/lb_policy/xds/xds_override_host.h \
 src/core/ext/filters/client_channel/lb_policy/xds/xds_wrr_locality.cc \
 src/core/ext/filters/client_channel/local_subchannel_pool.cc \
 src/core/ext/filters/client_channel/local_subchannel_pool.h \

tools/doxygen/Doxyfile.core.internal

@@ -944,6 +944,7 @@ src/core/ext/filters/client_channel/lb_policy/xds/xds_cluster_impl.cc \
 src/core/ext/filters/client_channel/lb_policy/xds/xds_cluster_manager.cc \
 src/core/ext/filters/client_channel/lb_policy/xds/xds_cluster_resolver.cc \
 src/core/ext/filters/client_channel/lb_policy/xds/xds_override_host.cc \
+src/core/ext/filters/client_channel/lb_policy/xds/xds_override_host.h \
 src/core/ext/filters/client_channel/lb_policy/xds/xds_wrr_locality.cc \
 src/core/ext/filters/client_channel/local_subchannel_pool.cc \
 src/core/ext/filters/client_channel/local_subchannel_pool.h \