| // |
| // 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. |
| // |
| |
| #ifndef GRPC_CORE_LIB_RESOLVER_RESOLVER_REGISTRY_H |
| #define GRPC_CORE_LIB_RESOLVER_RESOLVER_REGISTRY_H |
| |
| #include <grpc/support/port_platform.h> |
| |
| #include "src/core/lib/gprpp/memory.h" |
| #include "src/core/lib/gprpp/orphanable.h" |
| #include "src/core/lib/resolver/resolver_factory.h" |
| |
| namespace grpc_core { |
| |
| class ResolverRegistry { |
| private: |
| // Forward declaration needed to use this in Builder. |
| struct State { |
| std::map<absl::string_view, std::unique_ptr<ResolverFactory>> factories; |
| std::string default_prefix; |
| }; |
| |
| public: |
| /// Methods used to create and populate the ResolverRegistry. |
| /// NOT THREAD SAFE -- to be used only during global gRPC |
| /// initialization and shutdown. |
| class Builder { |
| public: |
| Builder(); |
| |
| /// Sets the default URI prefix to \a default_prefix. |
| void SetDefaultPrefix(std::string default_prefix); |
| |
| /// Registers a resolver factory. The factory will be used to create a |
| /// resolver for any URI whose scheme matches that of the factory. |
| void RegisterResolverFactory(std::unique_ptr<ResolverFactory> factory); |
| |
| /// Returns true iff scheme already has a registered factory. |
| bool HasResolverFactory(absl::string_view scheme) const; |
| |
| /// Wipe everything in the registry and reset to empty. |
| void Reset(); |
| |
| ResolverRegistry Build(); |
| |
| private: |
| ResolverRegistry::State state_; |
| }; |
| |
| ResolverRegistry(const ResolverRegistry&) = delete; |
| ResolverRegistry& operator=(const ResolverRegistry&) = delete; |
| ResolverRegistry(ResolverRegistry&&) noexcept; |
| ResolverRegistry& operator=(ResolverRegistry&&) noexcept; |
| |
| /// Checks whether the user input \a target is valid to create a resolver. |
| bool IsValidTarget(absl::string_view target) const; |
| |
| /// Creates a resolver given \a target. |
| /// First tries to parse \a target as a URI. If this succeeds, tries |
| /// to locate a registered resolver factory based on the URI scheme. |
| /// If parsing fails or there is no factory for the URI's scheme, |
| /// prepends default_prefix to target and tries again. |
| /// If a resolver factory is found, uses it to instantiate a resolver and |
| /// returns it; otherwise, returns nullptr. |
| /// \a args, \a pollset_set, and \a work_serializer are passed to the |
| /// factory's \a CreateResolver() method. \a args are the channel args to be |
| /// included in resolver results. \a pollset_set is used to drive I/O in the |
| /// name resolution process. \a work_serializer is the work_serializer under |
| /// which all resolver calls will be run. \a result_handler is used to return |
| /// results from the resolver. |
| OrphanablePtr<Resolver> CreateResolver( |
| absl::string_view target, const grpc_channel_args* args, |
| grpc_pollset_set* pollset_set, |
| std::shared_ptr<WorkSerializer> work_serializer, |
| std::unique_ptr<Resolver::ResultHandler> result_handler) const; |
| |
| /// Returns the default authority to pass from a client for \a target. |
| std::string GetDefaultAuthority(absl::string_view target) const; |
| |
| /// Returns \a target with the default prefix prepended, if needed. |
| std::string AddDefaultPrefixIfNeeded(absl::string_view target) const; |
| |
| /// Returns the resolver factory for \a scheme. |
| /// Caller does NOT own the return value. |
| ResolverFactory* LookupResolverFactory(absl::string_view scheme) const; |
| |
| private: |
| explicit ResolverRegistry(State state) : state_(std::move(state)) {} |
| |
| // TODO(ctiller): fix callers such that the canonical_target argument can be |
| // removed, and replaced with uri.ToString(). |
| ResolverFactory* FindResolverFactory(absl::string_view target, URI* uri, |
| std::string* canonical_target) const; |
| |
| State state_; |
| }; |
| |
| } // namespace grpc_core |
| |
| #endif // GRPC_CORE_LIB_RESOLVER_RESOLVER_REGISTRY_H |