diff --git a/BUILD b/BUILD index b6cf2798f91..b4d73fe208d 100644 --- a/BUILD +++ b/BUILD @@ -856,6 +856,17 @@ grpc_cc_library( deps = ["gpr_platform"], ) +grpc_cc_library( + name = "map", + language = "c++", + public_hdrs = ["src/core/lib/promise/map.h"], + deps = [ + "gpr_platform", + "poll", + "promise_like", + ], +) + grpc_cc_library( name = "promise", external_deps = [ diff --git a/CMakeLists.txt b/CMakeLists.txt index 1fdf1a2d57e..3b23031793c 100644 --- a/CMakeLists.txt +++ b/CMakeLists.txt @@ -916,6 +916,7 @@ if(gRPC_BUILD_TESTS) add_dependencies(buildtests_cxx popularity_count_test) add_dependencies(buildtests_cxx port_sharing_end2end_test) add_dependencies(buildtests_cxx promise_factory_test) + add_dependencies(buildtests_cxx promise_map_test) add_dependencies(buildtests_cxx promise_test) add_dependencies(buildtests_cxx proto_server_reflection_test) add_dependencies(buildtests_cxx proto_utils_test) @@ -13048,6 +13049,42 @@ target_link_libraries(promise_factory_test ) +endif() +if(gRPC_BUILD_TESTS) + +add_executable(promise_map_test + test/core/promise/map_test.cc + third_party/googletest/googletest/src/gtest-all.cc + third_party/googletest/googlemock/src/gmock-all.cc +) + +target_include_directories(promise_map_test + PRIVATE + ${CMAKE_CURRENT_SOURCE_DIR} + ${CMAKE_CURRENT_SOURCE_DIR}/include + ${_gRPC_ADDRESS_SORTING_INCLUDE_DIR} + ${_gRPC_RE2_INCLUDE_DIR} + ${_gRPC_SSL_INCLUDE_DIR} + ${_gRPC_UPB_GENERATED_DIR} + ${_gRPC_UPB_GRPC_GENERATED_DIR} + ${_gRPC_UPB_INCLUDE_DIR} + ${_gRPC_XXHASH_INCLUDE_DIR} + ${_gRPC_ZLIB_INCLUDE_DIR} + third_party/googletest/googletest/include + third_party/googletest/googletest + third_party/googletest/googlemock/include + third_party/googletest/googlemock + ${_gRPC_PROTO_GENS_DIR} +) + +target_link_libraries(promise_map_test + ${_gRPC_PROTOBUF_LIBRARIES} + ${_gRPC_ALLTARGETS_LIBRARIES} + absl::optional + absl::variant +) + + endif() if(gRPC_BUILD_TESTS) diff --git a/build_autogenerated.yaml b/build_autogenerated.yaml index 43de711a424..173dd9a1247 100644 --- a/build_autogenerated.yaml +++ b/build_autogenerated.yaml @@ -6077,6 +6077,21 @@ targets: - absl/types:variant - absl/utility:utility uses_polling: false +- name: promise_map_test + gtest: true + build: test + language: c++ + headers: + - src/core/lib/promise/detail/promise_like.h + - src/core/lib/promise/map.h + - src/core/lib/promise/poll.h + - src/core/lib/promise/promise.h + src: + - test/core/promise/map_test.cc + deps: + - absl/types:optional + - absl/types:variant + uses_polling: false - name: promise_test gtest: true build: test diff --git a/src/core/lib/promise/map.h b/src/core/lib/promise/map.h new file mode 100644 index 00000000000..a5b3e9e8377 --- /dev/null +++ b/src/core/lib/promise/map.h @@ -0,0 +1,64 @@ +// Copyright 2021 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_PROMISE_MAP_H +#define GRPC_CORE_LIB_PROMISE_MAP_H + +#include + +#include "absl/types/variant.h" +#include "src/core/lib/promise/detail/promise_like.h" +#include "src/core/lib/promise/poll.h" + +namespace grpc_core { + +namespace promise_detail { + +// Implementation of mapping combinator - use this via the free function below! +// Promise is the type of promise to poll on, Fn is a function that takes the +// result of Promise and maps it to some new type. +template +class Map { + public: + Map(Promise promise, Fn fn) + : promise_(std::move(promise)), fn_(std::move(fn)) {} + + using Result = typename PromiseLike::Result; + + Poll operator()() { + Poll r = promise_(); + if (auto* p = absl::get_if(&r)) { + return fn_(std::move(*p)); + } + return Pending(); + } + + private: + PromiseLike promise_; + Fn fn_; +}; + +} // namespace promise_detail + +// Mapping combinator. +// Takes a promise, and a synchronous function to mutate its result, and +// returns a promise. +template +promise_detail::Map Map(Promise promise, Fn fn) { + return promise_detail::Map(std::move(promise), std::move(fn)); +} + +} // namespace grpc_core + +#endif // GRPC_CORE_LIB_PROMISE_MAP_H diff --git a/test/core/promise/BUILD b/test/core/promise/BUILD index c7c4236ab56..fced9932e23 100644 --- a/test/core/promise/BUILD +++ b/test/core/promise/BUILD @@ -42,6 +42,24 @@ grpc_cc_test( ], ) +grpc_cc_test( + # Why promise_map_test and not map_test? + # third_party/benchmark defines a map_test in its cmakefile, and we depend + # on that from our cmakefile, and cmake wants to have a flat namespace to + # deal with xcode/visual studio limitations... sooo... promise_map_test it + # is. + name = "promise_map_test", + srcs = ["map_test.cc"], + external_deps = ["gtest"], + language = "c++", + uses_polling = False, + deps = [ + "//:map", + "//:promise", + "//test/core/util:grpc_suppressions", + ], +) + grpc_cc_test( name = "promise_factory_test", srcs = ["promise_factory_test.cc"], diff --git a/test/core/promise/map_test.cc b/test/core/promise/map_test.cc new file mode 100644 index 00000000000..0dfc50d6258 --- /dev/null +++ b/test/core/promise/map_test.cc @@ -0,0 +1,31 @@ +// Copyright 2021 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. + +#include "src/core/lib/promise/map.h" +#include +#include "src/core/lib/promise/promise.h" + +namespace grpc_core { + +TEST(MapTest, Works) { + Promise x = Map([]() { return 42; }, [](int i) { return i / 2; }); + EXPECT_EQ(x(), Poll(21)); +} + +} // namespace grpc_core + +int main(int argc, char** argv) { + ::testing::InitGoogleTest(&argc, argv); + return RUN_ALL_TESTS(); +} diff --git a/tools/run_tests/generated/tests.json b/tools/run_tests/generated/tests.json index 08ae7ae327b..e5ade4a05a9 100644 --- a/tools/run_tests/generated/tests.json +++ b/tools/run_tests/generated/tests.json @@ -5681,6 +5681,30 @@ ], "uses_polling": false }, + { + "args": [], + "benchmark": false, + "ci_platforms": [ + "linux", + "mac", + "posix", + "windows" + ], + "cpu_cost": 1.0, + "exclude_configs": [], + "exclude_iomgrs": [], + "flaky": false, + "gtest": true, + "language": "c++", + "name": "promise_map_test", + "platforms": [ + "linux", + "mac", + "posix", + "windows" + ], + "uses_polling": false + }, { "args": [], "benchmark": false,