--- /dev/null
+/*
+ *
+ * Copyright 2015 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.
+ *
+ */
+
+#include <grpc/support/port_platform.h>
+
+#include "src/core/ext/filters/client_channel/lb_policy_registry.h"
+
+#include <string.h>
+
+#include "src/core/lib/gpr/string.h"
+#include "src/core/lib/gprpp/inlined_vector.h"
+
+namespace grpc_core {
+
+namespace {
+
+class RegistryState {
+ public:
+ RegistryState() {}
+
+ void RegisterLoadBalancingPolicyFactory(
+ UniquePtr<LoadBalancingPolicyFactory> factory) {
+ for (size_t i = 0; i < factories_.size(); ++i) {
+ GPR_ASSERT(strcmp(factories_[i]->name(), factory->name()) != 0);
+ }
+ factories_.push_back(std::move(factory));
+ }
+
+ LoadBalancingPolicyFactory* GetLoadBalancingPolicyFactory(
+ const char* name) const {
+ for (size_t i = 0; i < factories_.size(); ++i) {
+ if (strcmp(name, factories_[i]->name()) == 0) {
+ return factories_[i].get();
+ }
+ }
+ return nullptr;
+ }
+
+ private:
+ InlinedVector<UniquePtr<LoadBalancingPolicyFactory>, 10> factories_;
+};
+
+RegistryState* g_state = nullptr;
+
+} // namespace
+
+//
+// LoadBalancingPolicyRegistry::Builder
+//
+
+void LoadBalancingPolicyRegistry::Builder::InitRegistry() {
+ if (g_state == nullptr) g_state = New<RegistryState>();
+}
+
+void LoadBalancingPolicyRegistry::Builder::ShutdownRegistry() {
+ Delete(g_state);
+ g_state = nullptr;
+}
+
+void LoadBalancingPolicyRegistry::Builder::RegisterLoadBalancingPolicyFactory(
+ UniquePtr<LoadBalancingPolicyFactory> factory) {
+ InitRegistry();
+ g_state->RegisterLoadBalancingPolicyFactory(std::move(factory));
+}
+
+//
+// LoadBalancingPolicyRegistry
+//
+
+OrphanablePtr<LoadBalancingPolicy>
+LoadBalancingPolicyRegistry::CreateLoadBalancingPolicy(
+ const char* name, LoadBalancingPolicy::Args args) {
+ GPR_ASSERT(g_state != nullptr);
+ // Find factory.
+ LoadBalancingPolicyFactory* factory =
+ g_state->GetLoadBalancingPolicyFactory(name);
+ if (factory == nullptr) return nullptr; // Specified name not found.
+ // Create policy via factory.
+ return factory->CreateLoadBalancingPolicy(std::move(args));
+}
+
+bool LoadBalancingPolicyRegistry::LoadBalancingPolicyExists(
+ const char* name, bool* requires_config) {
+ GPR_ASSERT(g_state != nullptr);
+ auto* factory = g_state->GetLoadBalancingPolicyFactory(name);
+ if (factory == nullptr) {
+ return false;
+ }
+ if (requires_config != nullptr) {
+ grpc_error* error = GRPC_ERROR_NONE;
+ // Check if the load balancing policy allows an empty config
+ *requires_config =
+ factory->ParseLoadBalancingConfig(nullptr, &error) == nullptr;
+ GRPC_ERROR_UNREF(error);
+ }
+ return true;
+}
+
+namespace {
+// Returns the JSON node of policy (with both policy name and config content)
+// given the JSON node of a LoadBalancingConfig array.
+grpc_json* ParseLoadBalancingConfigHelper(const grpc_json* lb_config_array,
+ grpc_error** error) {
+ GPR_DEBUG_ASSERT(error != nullptr && *error == GRPC_ERROR_NONE);
+ if (lb_config_array == nullptr) {
+ *error =
+ GRPC_ERROR_CREATE_FROM_STATIC_STRING("LB config JSON tree is null");
+ return nullptr;
+ }
+ char* error_msg;
+ if (lb_config_array->type != GRPC_JSON_ARRAY) {
+ gpr_asprintf(&error_msg, "field:%s error:type should be array",
+ lb_config_array->key);
+ *error = GRPC_ERROR_CREATE_FROM_COPIED_STRING(error_msg);
+ gpr_free(error_msg);
+ return nullptr;
+ }
+ const char* field_name = lb_config_array->key;
+ // Find the first LB policy that this client supports.
+ for (const grpc_json* lb_config = lb_config_array->child;
+ lb_config != nullptr; lb_config = lb_config->next) {
+ if (lb_config->type != GRPC_JSON_OBJECT) {
+ gpr_asprintf(&error_msg,
+ "field:%s error:child entry should be of type object",
+ field_name);
+ *error = GRPC_ERROR_CREATE_FROM_COPIED_STRING(error_msg);
+ gpr_free(error_msg);
+ return nullptr;
+ }
+ grpc_json* policy = nullptr;
+ for (grpc_json* field = lb_config->child; field != nullptr;
+ field = field->next) {
+ if (field->key == nullptr || field->type != GRPC_JSON_OBJECT) {
+ gpr_asprintf(&error_msg,
+ "field:%s error:child entry should be of type object",
+ field_name);
+ *error = GRPC_ERROR_CREATE_FROM_COPIED_STRING(error_msg);
+ gpr_free(error_msg);
+ return nullptr;
+ }
+ if (policy != nullptr) {
+ gpr_asprintf(&error_msg, "field:%s error:oneOf violation", field_name);
+ *error = GRPC_ERROR_CREATE_FROM_COPIED_STRING(error_msg);
+ gpr_free(error_msg);
+ return nullptr;
+ } // Violate "oneof" type.
+ policy = field;
+ }
+ if (policy == nullptr) {
+ gpr_asprintf(&error_msg, "field:%s error:no policy found in child entry",
+ field_name);
+ *error = GRPC_ERROR_CREATE_FROM_COPIED_STRING(error_msg);
+ gpr_free(error_msg);
+ return nullptr;
+ }
+ // If we support this policy, then select it.
+ if (LoadBalancingPolicyRegistry::LoadBalancingPolicyExists(policy->key,
+ nullptr)) {
+ return policy;
+ }
+ }
+ gpr_asprintf(&error_msg, "field:%s error:No known policy", field_name);
+ *error = GRPC_ERROR_CREATE_FROM_COPIED_STRING(error_msg);
+ gpr_free(error_msg);
+ return nullptr;
+}
+} // namespace
+
+RefCountedPtr<LoadBalancingPolicy::Config>
+LoadBalancingPolicyRegistry::ParseLoadBalancingConfig(const grpc_json* json,
+ grpc_error** error) {
+ GPR_DEBUG_ASSERT(error != nullptr && *error == GRPC_ERROR_NONE);
+ GPR_ASSERT(g_state != nullptr);
+ const grpc_json* policy = ParseLoadBalancingConfigHelper(json, error);
+ if (policy == nullptr) {
+ return nullptr;
+ } else {
+ GPR_DEBUG_ASSERT(*error == GRPC_ERROR_NONE && json != nullptr);
+ // Find factory.
+ LoadBalancingPolicyFactory* factory =
+ g_state->GetLoadBalancingPolicyFactory(policy->key);
+ if (factory == nullptr) {
+ char* msg;
+ gpr_asprintf(&msg, "field:%s error:Factory not found to create policy",
+ json->key);
+ *error = GRPC_ERROR_CREATE_FROM_COPIED_STRING(msg);
+ gpr_free(msg);
+ return nullptr;
+ }
+ // Parse load balancing config via factory.
+ return factory->ParseLoadBalancingConfig(policy, error);
+ }
+}
+
+} // namespace grpc_core
git://repos.xcallymotion.com / motion2.git / blobdiff