resolver_registry.h

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//
// 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 <map>
#include <memory>
#include <string>
#include <utility>
 
#include "absl/strings/string_view.h"
 
#include <grpc/impl/codegen/grpc_types.h>
 
#include "src/core/lib/gprpp/orphanable.h"
#include "src/core/lib/iomgr/iomgr_fwd.h"
#include "src/core/lib/resolver/resolver.h"
#include "src/core/lib/resolver/resolver_factory.h"
#include "src/core/lib/uri/uri_parser.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:
  class Builder {
   public:
    Builder();
 
    void SetDefaultPrefix(std::string default_prefix);
 
    void RegisterResolverFactory(std::unique_ptr<ResolverFactory> factory);
 
    bool HasResolverFactory(absl::string_view scheme) const;
 
    void Reset();
 
    ResolverRegistry Build();
 
   private:
    ResolverRegistry::State state_;
  };
 
  ResolverRegistry(const ResolverRegistry&) = delete;
  ResolverRegistry& operator=(const ResolverRegistry&) = delete;
  ResolverRegistry(ResolverRegistry&&) noexcept;
  ResolverRegistry& operator=(ResolverRegistry&&) noexcept;
 
  bool IsValidTarget(absl::string_view target) const;
 
  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;
 
  std::string GetDefaultAuthority(absl::string_view target) const;
 
  std::string AddDefaultPrefixIfNeeded(absl::string_view target) const;
 
  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