| // |
| // Copyright 2016 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_SERVICE_CONFIG_H |
| #define GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_SERVICE_CONFIG_H |
| |
| #include <grpc/support/port_platform.h> |
| |
| #include <unordered_map> |
| |
| #include "absl/container/inlined_vector.h" |
| |
| #include <grpc/impl/codegen/grpc_types.h> |
| #include <grpc/support/string_util.h> |
| |
| #include "src/core/lib/gprpp/ref_counted.h" |
| #include "src/core/lib/gprpp/ref_counted_ptr.h" |
| #include "src/core/lib/iomgr/error.h" |
| #include "src/core/lib/json/json.h" |
| #include "src/core/lib/slice/slice_internal.h" |
| |
| // The main purpose of the code here is to parse the service config in |
| // JSON form, which will look like this: |
| // |
| // { |
| // "loadBalancingPolicy": "string", // optional |
| // "methodConfig": [ // array of one or more method_config objects |
| // { |
| // "name": [ // array of one or more name objects |
| // { |
| // "service": "string", // required |
| // "method": "string", // optional |
| // } |
| // ], |
| // // remaining fields are optional. |
| // // see https://developers.google.com/protocol-buffers/docs/proto3#json |
| // // for format details. |
| // "waitForReady": bool, |
| // "timeout": "duration_string", |
| // "maxRequestMessageBytes": "int64_string", |
| // "maxResponseMessageBytes": "int64_string", |
| // } |
| // ] |
| // } |
| |
| namespace grpc_core { |
| |
| class ServiceConfig : public RefCounted<ServiceConfig> { |
| public: |
| /// This is the base class that all service config parsers MUST use to store |
| /// parsed service config data. |
| class ParsedConfig { |
| public: |
| virtual ~ParsedConfig() = default; |
| }; |
| |
| /// This is the base class that all service config parsers should derive from. |
| class Parser { |
| public: |
| virtual ~Parser() = default; |
| |
| virtual std::unique_ptr<ParsedConfig> ParseGlobalParams( |
| const Json& /* json */, grpc_error** error) { |
| // Avoid unused parameter warning on debug-only parameter |
| (void)error; |
| GPR_DEBUG_ASSERT(error != nullptr); |
| return nullptr; |
| } |
| |
| virtual std::unique_ptr<ParsedConfig> ParsePerMethodParams( |
| const Json& /* json */, grpc_error** error) { |
| // Avoid unused parameter warning on debug-only parameter |
| (void)error; |
| GPR_DEBUG_ASSERT(error != nullptr); |
| return nullptr; |
| } |
| }; |
| |
| static constexpr int kNumPreallocatedParsers = 4; |
| typedef absl::InlinedVector<std::unique_ptr<ParsedConfig>, |
| kNumPreallocatedParsers> |
| ParsedConfigVector; |
| |
| /// When a service config is applied to a call in the client_channel_filter, |
| /// we create an instance of this object and store it in the call_data for |
| /// client_channel. A pointer to this object is also stored in the |
| /// call_context, so that future filters can easily access method and global |
| /// parameters for the call. |
| class CallData { |
| public: |
| CallData() = default; |
| CallData(RefCountedPtr<ServiceConfig> svc_cfg, const grpc_slice& path) |
| : service_config_(std::move(svc_cfg)) { |
| if (service_config_ != nullptr) { |
| method_params_vector_ = |
| service_config_->GetMethodParsedConfigVector(path); |
| } |
| } |
| |
| ServiceConfig* service_config() { return service_config_.get(); } |
| |
| ParsedConfig* GetMethodParsedConfig(size_t index) const { |
| return method_params_vector_ != nullptr |
| ? (*method_params_vector_)[index].get() |
| : nullptr; |
| } |
| |
| ParsedConfig* GetGlobalParsedConfig(size_t index) const { |
| return service_config_->GetGlobalParsedConfig(index); |
| } |
| |
| private: |
| RefCountedPtr<ServiceConfig> service_config_; |
| const ParsedConfigVector* method_params_vector_ = nullptr; |
| }; |
| |
| /// Creates a new service config from parsing \a json_string. |
| /// Returns null on parse error. |
| static RefCountedPtr<ServiceConfig> Create(StringView json_string, |
| grpc_error** error); |
| |
| ServiceConfig(std::string json_string, Json json, grpc_error** error); |
| ~ServiceConfig(); |
| |
| const std::string& json_string() const { return json_string_; } |
| |
| /// Retrieves the global parsed config at index \a index. The |
| /// lifetime of the returned object is tied to the lifetime of the |
| /// ServiceConfig object. |
| ParsedConfig* GetGlobalParsedConfig(size_t index) { |
| GPR_DEBUG_ASSERT(index < parsed_global_configs_.size()); |
| return parsed_global_configs_[index].get(); |
| } |
| |
| /// Retrieves the vector of parsed configs for the method identified |
| /// by \a path. The lifetime of the returned vector and contained objects |
| /// is tied to the lifetime of the ServiceConfig object. |
| const ParsedConfigVector* GetMethodParsedConfigVector( |
| const grpc_slice& path) const; |
| |
| /// Globally register a service config parser. On successful registration, it |
| /// returns the index at which the parser was registered. On failure, -1 is |
| /// returned. Each new service config update will go through all the |
| /// registered parser. Each parser is responsible for reading the service |
| /// config json and returning a parsed config. This parsed config can later be |
| /// retrieved using the same index that was returned at registration time. |
| static size_t RegisterParser(std::unique_ptr<Parser> parser); |
| |
| static void Init(); |
| |
| static void Shutdown(); |
| |
| private: |
| // Helper functions to parse the service config |
| grpc_error* ParseGlobalParams(); |
| grpc_error* ParsePerMethodParams(); |
| |
| // Returns a path string for the JSON name object specified by json. |
| // Sets *error on error. |
| static std::string ParseJsonMethodName(const Json& json, grpc_error** error); |
| |
| grpc_error* ParseJsonMethodConfig(const Json& json); |
| |
| std::string json_string_; |
| Json json_; |
| |
| absl::InlinedVector<std::unique_ptr<ParsedConfig>, kNumPreallocatedParsers> |
| parsed_global_configs_; |
| // A map from the method name to the parsed config vector. Note that we are |
| // using a raw pointer and not a unique pointer so that we can use the same |
| // vector for multiple names. |
| std::unordered_map<grpc_slice, const ParsedConfigVector*, SliceHash> |
| parsed_method_configs_map_; |
| // Default method config. |
| const ParsedConfigVector* default_method_config_vector_ = nullptr; |
| // Storage for all the vectors that are being used in |
| // parsed_method_configs_table_. |
| absl::InlinedVector<std::unique_ptr<ParsedConfigVector>, 32> |
| parsed_method_config_vectors_storage_; |
| }; |
| |
| } // namespace grpc_core |
| |
| #endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_SERVICE_CONFIG_H */ |