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Diffstat (limited to 'src/core/ext/filters/client_channel/resolver_result_parsing.h')
-rw-r--r-- | src/core/ext/filters/client_channel/resolver_result_parsing.h | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/src/core/ext/filters/client_channel/resolver_result_parsing.h b/src/core/ext/filters/client_channel/resolver_result_parsing.h new file mode 100644 index 0000000000..f1fb7406bc --- /dev/null +++ b/src/core/ext/filters/client_channel/resolver_result_parsing.h @@ -0,0 +1,146 @@ +/* + * + * Copyright 2018 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_RESOLVER_RESULT_PARSING_H +#define GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RESOLVER_RESULT_PARSING_H + +#include <grpc/support/port_platform.h> + +#include "src/core/ext/filters/client_channel/retry_throttle.h" +#include "src/core/lib/channel/status_util.h" +#include "src/core/lib/gprpp/ref_counted.h" +#include "src/core/lib/gprpp/ref_counted_ptr.h" +#include "src/core/lib/iomgr/exec_ctx.h" // for grpc_millis +#include "src/core/lib/json/json.h" +#include "src/core/lib/slice/slice_hash_table.h" +#include "src/core/lib/transport/service_config.h" + +namespace grpc_core { +namespace internal { + +class ClientChannelMethodParams; + +// A table mapping from a method name to its method parameters. +typedef grpc_core::SliceHashTable< + grpc_core::RefCountedPtr<ClientChannelMethodParams>> + ClientChannelMethodParamsTable; + +// A container of processed fields from the resolver result. Simplifies the +// usage of resolver result. +class ProcessedResolverResult { + public: + // Processes the resolver result and populates the relative members + // for later consumption. Tries to parse retry parameters only if parse_retry + // is true. + ProcessedResolverResult(const grpc_channel_args* resolver_result, + bool parse_retry); + + // Getters. Any managed object's ownership is transferred. + grpc_core::UniquePtr<char> service_config_json() { + return std::move(service_config_json_); + } + grpc_core::RefCountedPtr<ServerRetryThrottleData> retry_throttle_data() { + return std::move(retry_throttle_data_); + } + grpc_core::RefCountedPtr<ClientChannelMethodParamsTable> + method_params_table() { + return std::move(method_params_table_); + } + grpc_core::UniquePtr<char> lb_policy_name() { + return std::move(lb_policy_name_); + } + grpc_json* lb_policy_config() { return lb_policy_config_; } + + private: + // Finds the service config; extracts LB config and (maybe) retry throttle + // params from it. + void ProcessServiceConfig(const grpc_channel_args* resolver_result, + bool parse_retry); + + // Finds the LB policy name (when no LB config was found). + void ProcessLbPolicyName(const grpc_channel_args* resolver_result); + + // Parses the service config. Intended to be used by + // ServiceConfig::ParseGlobalParams. + static void ParseServiceConfig(const grpc_json* field, + ProcessedResolverResult* parsing_state); + // Parses the LB config from service config. + void ParseLbConfigFromServiceConfig(const grpc_json* field); + // Parses the retry throttle parameters from service config. + void ParseRetryThrottleParamsFromServiceConfig(const grpc_json* field); + + // Service config. + grpc_core::UniquePtr<char> service_config_json_; + grpc_core::UniquePtr<grpc_core::ServiceConfig> service_config_; + // LB policy. + grpc_json* lb_policy_config_ = nullptr; + grpc_core::UniquePtr<char> lb_policy_name_; + // Retry throttle data. + char* server_name_ = nullptr; + grpc_core::RefCountedPtr<ServerRetryThrottleData> retry_throttle_data_; + // Method params table. + grpc_core::RefCountedPtr<ClientChannelMethodParamsTable> method_params_table_; +}; + +// The parameters of a method. +class ClientChannelMethodParams : public RefCounted<ClientChannelMethodParams> { + public: + enum WaitForReady { + WAIT_FOR_READY_UNSET = 0, + WAIT_FOR_READY_FALSE, + WAIT_FOR_READY_TRUE + }; + + struct RetryPolicy { + int max_attempts = 0; + grpc_millis initial_backoff = 0; + grpc_millis max_backoff = 0; + float backoff_multiplier = 0; + StatusCodeSet retryable_status_codes; + }; + + /// Creates a method_parameters object from \a json. + /// Intended for use with ServiceConfig::CreateMethodConfigTable(). + static RefCountedPtr<ClientChannelMethodParams> CreateFromJson( + const grpc_json* json); + + grpc_millis timeout() const { return timeout_; } + WaitForReady wait_for_ready() const { return wait_for_ready_; } + const RetryPolicy* retry_policy() const { return retry_policy_.get(); } + + private: + // So New() can call our private ctor. + template <typename T, typename... Args> + friend T* grpc_core::New(Args&&... args); + + // So Delete() can call our private dtor. + template <typename T> + friend void grpc_core::Delete(T*); + + ClientChannelMethodParams() {} + virtual ~ClientChannelMethodParams() {} + + grpc_millis timeout_ = 0; + WaitForReady wait_for_ready_ = WAIT_FOR_READY_UNSET; + UniquePtr<RetryPolicy> retry_policy_; +}; + +} // namespace internal +} // namespace grpc_core + +#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RESOLVER_RESULT_PARSING_H */ |