Use a single copy of CreateErrorFromVector from ServiceConfig

src/core/ext/filters/client_channel/client_channel.cc

@@ -3080,6 +3080,9 @@ void CallData::ApplyServiceConfigToCallLocked(grpc_call_element* elem) {
             chand, this);
   }
   if (chand->service_config() != nullptr) {
+    // Store a ref to the service_config in CallData. Also, save pointers to the
+    // ServiceConfig and ServiceConfigObjectsVector (for this call) in the
+    // call_context so that all future filters can access it.
     service_config_ = chand->service_config();
     call_context_[GRPC_SERVICE_CONFIG].value = &service_config_;
     const auto* method_params_vector_ptr =

src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.cc

@@ -1798,24 +1798,6 @@ void GrpcLb::CreateOrUpdateChildPolicyLocked() {
   policy_to_update->UpdateLocked(std::move(update_args));
 }
 
-// Consumes all the errors in the vector and forms a referencing error from
-// them. If the vector is empty, return GRPC_ERROR_NONE.
-template <size_t N>
-grpc_error* CreateErrorFromVector(const char* desc,
-                                  InlinedVector<grpc_error*, N>* error_list) {
-  grpc_error* error = GRPC_ERROR_NONE;
-  if (error_list->size() != 0) {
-    error = GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(
-        desc, error_list->data(), error_list->size());
-    // Remove refs to all errors in error_list.
-    for (size_t i = 0; i < error_list->size(); i++) {
-      GRPC_ERROR_UNREF((*error_list)[i]);
-    }
-    error_list->clear();
-  }
-  return error;
-}
-
 //
 // factory
 //
@@ -1858,7 +1840,8 @@ class GrpcLbFactory : public LoadBalancingPolicyFactory {
       return UniquePtr<ParsedLoadBalancingConfig>(
           New<ParsedGrpcLbConfig>(std::move(child_policy)));
     } else {
-      *error = CreateErrorFromVector("GrpcLb Parser", &error_list);
+      *error =
+          ServiceConfig::CreateErrorFromVector("GrpcLb Parser", &error_list);
       return nullptr;
     }
   }

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

@@ -1652,24 +1652,6 @@ void XdsLb::LocalityMap::LocalityEntry::Helper::RequestReresolution() {
   }
 }
 
-// Consumes all the errors in the vector and forms a referencing error from
-// them. If the vector is empty, return GRPC_ERROR_NONE.
-template <size_t N>
-grpc_error* CreateErrorFromVector(const char* desc,
-                                  InlinedVector<grpc_error*, N>* error_list) {
-  grpc_error* error = GRPC_ERROR_NONE;
-  if (error_list->size() != 0) {
-    error = GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(
-        desc, error_list->data(), error_list->size());
-    // Remove refs to all errors in error_list.
-    for (size_t i = 0; i < error_list->size(); i++) {
-      GRPC_ERROR_UNREF((*error_list)[i]);
-    }
-    error_list->clear();
-  }
-  return error;
-}
-
 //
 // factory
 //
@@ -1743,7 +1725,7 @@ class XdsFactory : public LoadBalancingPolicyFactory {
       return UniquePtr<ParsedLoadBalancingConfig>(New<ParsedXdsConfig>(
           balancer_name, std::move(child_policy), std::move(fallback_policy)));
     } else {
-      *error = CreateErrorFromVector("Xds Parser", &error_list);
+      *error = ServiceConfig::CreateErrorFromVector("Xds Parser", &error_list);
       return nullptr;
     }
   }

src/core/ext/filters/client_channel/resolver_result_parsing.cc

@@ -79,26 +79,6 @@ ProcessedResolverResult::ProcessedResolverResult(
   if (lb_policy_name_ == nullptr) ProcessLbPolicyName(*resolver_result);
 }
 
-namespace {
-// Consumes all the errors in the vector and forms a referencing error from
-// them. If the vector is empty, return GRPC_ERROR_NONE.
-template <size_t N>
-grpc_error* CreateErrorFromVector(const char* desc,
-                                  InlinedVector<grpc_error*, N>* error_list) {
-  grpc_error* error = GRPC_ERROR_NONE;
-  if (error_list->size() != 0) {
-    error = GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(
-        desc, error_list->data(), error_list->size());
-    // Remove refs to all errors in error_list.
-    for (size_t i = 0; i < error_list->size(); i++) {
-      GRPC_ERROR_UNREF((*error_list)[i]);
-    }
-    error_list->clear();
-  }
-  return error;
-}
-}  // namespace
-
 void ProcessedResolverResult::ProcessServiceConfig(
     const Resolver::Result& resolver_result, bool parse_retry) {
   if (service_config_ == nullptr) return;
@@ -349,7 +329,7 @@ UniquePtr<ClientChannelMethodParsedObject::RetryPolicy> ParseRetryPolicy(
       return nullptr;
     }
   }
-  *error = CreateErrorFromVector("retryPolicy", &error_list);
+  *error = ServiceConfig::CreateErrorFromVector("retryPolicy", &error_list);
   return *error == GRPC_ERROR_NONE ? std::move(retry_policy) : nullptr;
 }
 
@@ -504,7 +484,8 @@ ClientChannelServiceConfigParser::ParseGlobalParams(const grpc_json* json,
       }
     }
   }
-  *error = CreateErrorFromVector("Client channel global parser", &error_list);
+  *error = ServiceConfig::CreateErrorFromVector("Client channel global parser",
+                                                &error_list);
   if (*error == GRPC_ERROR_NONE) {
     return UniquePtr<ServiceConfigParsedObject>(
         New<ClientChannelGlobalParsedObject>(std::move(parsed_lb_config),
@@ -560,7 +541,8 @@ ClientChannelServiceConfigParser::ParsePerMethodParams(const grpc_json* json,
       }
     }
   }
-  *error = CreateErrorFromVector("Client channel parser", &error_list);
+  *error = ServiceConfig::CreateErrorFromVector("Client channel parser",
+                                                &error_list);
   if (*error == GRPC_ERROR_NONE) {
     return UniquePtr<ServiceConfigParsedObject>(
         New<ClientChannelMethodParsedObject>(timeout, wait_for_ready,

src/core/ext/filters/client_channel/service_config.cc

@@ -38,24 +38,6 @@ typedef InlinedVector<UniquePtr<ServiceConfigParser>,
                       ServiceConfig::kNumPreallocatedParsers>
     ServiceConfigParserList;
 ServiceConfigParserList* g_registered_parsers;
-
-// Consumes all the errors in the vector and forms a referencing error from
-// them. If the vector is empty, return GRPC_ERROR_NONE.
-template <size_t N>
-grpc_error* CreateErrorFromVector(const char* desc,
-                                  InlinedVector<grpc_error*, N>* error_list) {
-  grpc_error* error = GRPC_ERROR_NONE;
-  if (error_list->size() != 0) {
-    error = GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(
-        desc, error_list->data(), error_list->size());
-    // Remove refs to all errors in error_list.
-    for (size_t i = 0; i < error_list->size(); i++) {
-      GRPC_ERROR_UNREF((*error_list)[i]);
-    }
-    error_list->clear();
-  }
-  return error;
-}
 }  // namespace
 
 RefCountedPtr<ServiceConfig> ServiceConfig::Create(const char* json,

src/core/ext/filters/client_channel/service_config.h

@@ -150,6 +150,24 @@ class ServiceConfig : public RefCounted<ServiceConfig> {
 
   static void Shutdown();
 
+  // Consumes all the errors in the vector and forms a referencing error from
+  // them. If the vector is empty, return GRPC_ERROR_NONE.
+  template <size_t N>
+  static grpc_error* CreateErrorFromVector(
+      const char* desc, InlinedVector<grpc_error*, N>* error_list) {
+    grpc_error* error = GRPC_ERROR_NONE;
+    if (error_list->size() != 0) {
+      error = GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(
+          desc, error_list->data(), error_list->size());
+      // Remove refs to all errors in error_list.
+      for (size_t i = 0; i < error_list->size(); i++) {
+        GRPC_ERROR_UNREF((*error_list)[i]);
+      }
+      error_list->clear();
+    }
+    return error;
+  }
+
  private:
   // So New() can call our private ctor.
   template <typename T, typename... Args>

src/core/ext/filters/message_size/message_size_parser.cc

@@ -22,24 +22,6 @@
 
 namespace {
 size_t g_message_size_parser_index;
-
-// Consumes all the errors in the vector and forms a referencing error from
-// them. If the vector is empty, return GRPC_ERROR_NONE.
-template <size_t N>
-grpc_error* CreateErrorFromVector(
-    const char* desc, grpc_core::InlinedVector<grpc_error*, N>* error_list) {
-  grpc_error* error = GRPC_ERROR_NONE;
-  if (error_list->size() != 0) {
-    error = GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(
-        desc, error_list->data(), error_list->size());
-    // Remove refs to all errors in error_list.
-    for (size_t i = 0; i < error_list->size(); i++) {
-      GRPC_ERROR_UNREF((*error_list)[i]);
-    }
-    error_list->clear();
-  }
-  return error;
-}
 }  // namespace
 
 namespace grpc_core {
@@ -85,7 +67,8 @@ UniquePtr<ServiceConfigParsedObject> MessageSizeParser::ParsePerMethodParams(
     }
   }
   if (!error_list.empty()) {
-    *error = CreateErrorFromVector("Message size parser", &error_list);
+    *error = ServiceConfig::CreateErrorFromVector("Message size parser",
+                                                  &error_list);
     return nullptr;
   }
   return UniquePtr<ServiceConfigParsedObject>(New<MessageSizeParsedObject>(