| // |
| // 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_SRC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RESOLVER_FAKE_FAKE_RESOLVER_H |
| #define GRPC_SRC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RESOLVER_FAKE_FAKE_RESOLVER_H |
| |
| #include <grpc/support/port_platform.h> |
| |
| #include "absl/base/thread_annotations.h" |
| #include "absl/strings/string_view.h" |
| |
| #include <grpc/grpc.h> |
| |
| #include "src/core/lib/gpr/useful.h" |
| #include "src/core/lib/gprpp/ref_counted.h" |
| #include "src/core/lib/gprpp/ref_counted_ptr.h" |
| #include "src/core/lib/gprpp/sync.h" |
| #include "src/core/lib/resolver/resolver.h" |
| |
| #define GRPC_ARG_FAKE_RESOLVER_RESPONSE_GENERATOR \ |
| "grpc.fake_resolver.response_generator" |
| |
| namespace grpc_core { |
| |
| class FakeResolver; |
| |
| /// A mechanism for generating responses for the fake resolver. |
| /// An instance of this class is passed to the fake resolver via a channel |
| /// argument (see \a MakeChannelArg()) and used to inject and trigger custom |
| /// resolutions. |
| // TODO(roth): I would ideally like this to be InternallyRefCounted |
| // instead of RefCounted, but external refs are currently needed to |
| // encode this in channel args. Once channel_args are converted to C++, |
| // see if we can find a way to fix this. |
| class FakeResolverResponseGenerator |
| : public RefCounted<FakeResolverResponseGenerator> { |
| public: |
| static const grpc_arg_pointer_vtable kChannelArgPointerVtable; |
| |
| FakeResolverResponseGenerator(); |
| ~FakeResolverResponseGenerator() override; |
| |
| // Instructs the fake resolver associated with the response generator |
| // instance to trigger a new resolution with the specified result. If the |
| // resolver is not available yet, delays response setting until it is. This |
| // can be called at most once before the resolver is available. |
| void SetResponse(Resolver::Result result); |
| |
| // Sets the re-resolution response, which is returned by the fake resolver |
| // when re-resolution is requested (via \a RequestReresolutionLocked()). |
| // The new re-resolution response replaces any previous re-resolution |
| // response that may have been set by a previous call. |
| void SetReresolutionResponse(Resolver::Result result); |
| |
| // Unsets the re-resolution response. After this, the fake resolver will |
| // not return anything when \a RequestReresolutionLocked() is called. |
| void UnsetReresolutionResponse(); |
| |
| // Tells the resolver to return a transient failure. |
| void SetFailure(); |
| |
| // Same as SetFailure(), but instead of returning the error |
| // immediately, waits for the next call to RequestReresolutionLocked(). |
| void SetFailureOnReresolution(); |
| |
| // Returns a channel arg containing \a generator. |
| // TODO(roth): When we have time, make this a non-static method. |
| static grpc_arg MakeChannelArg(FakeResolverResponseGenerator* generator); |
| |
| // Returns the response generator in \a args, or null if not found. |
| static RefCountedPtr<FakeResolverResponseGenerator> GetFromArgs( |
| const grpc_channel_args* args); |
| |
| static absl::string_view ChannelArgName() { |
| return GRPC_ARG_FAKE_RESOLVER_RESPONSE_GENERATOR; |
| } |
| |
| static int ChannelArgsCompare(const FakeResolverResponseGenerator* a, |
| const FakeResolverResponseGenerator* b) { |
| return QsortCompare(a, b); |
| } |
| |
| private: |
| friend class FakeResolver; |
| // Set the corresponding FakeResolver to this generator. |
| void SetFakeResolver(RefCountedPtr<FakeResolver> resolver); |
| |
| // Mutex protecting the members below. |
| Mutex mu_; |
| RefCountedPtr<FakeResolver> resolver_ ABSL_GUARDED_BY(mu_); |
| Resolver::Result result_ ABSL_GUARDED_BY(mu_); |
| bool has_result_ ABSL_GUARDED_BY(mu_) = false; |
| }; |
| |
| } // namespace grpc_core |
| |
| #endif // GRPC_SRC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RESOLVER_FAKE_FAKE_RESOLVER_H |