| # Copyright 2021 The Pigweed 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 |
| # |
| # https://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. |
| """This module generates the code for nanopb-based pw_rpc services.""" |
| |
| import os |
| from typing import Iterable, NamedTuple, Optional |
| |
| from pw_protobuf.output_file import OutputFile |
| from pw_protobuf.proto_tree import ProtoServiceMethod |
| from pw_protobuf.proto_tree import build_node_tree |
| from pw_rpc import codegen |
| from pw_rpc.codegen import (client_call_type, get_id, CodeGenerator, |
| RPC_NAMESPACE) |
| |
| PROTO_H_EXTENSION = '.pb.h' |
| PROTO_CC_EXTENSION = '.pb.cc' |
| NANOPB_H_EXTENSION = '.pb.h' |
| |
| |
| def _serde(method: ProtoServiceMethod) -> str: |
| """Returns the NanopbMethodSerde for this method.""" |
| return (f'{RPC_NAMESPACE}::internal::kNanopbMethodSerde<' |
| f'{method.request_type().nanopb_fields()}, ' |
| f'{method.response_type().nanopb_fields()}>') |
| |
| |
| def _proto_filename_to_nanopb_header(proto_file: str) -> str: |
| """Returns the generated nanopb header name for a .proto file.""" |
| return os.path.splitext(proto_file)[0] + NANOPB_H_EXTENSION |
| |
| |
| def _proto_filename_to_generated_header(proto_file: str) -> str: |
| """Returns the generated C++ RPC header name for a .proto file.""" |
| filename = os.path.splitext(proto_file)[0] |
| return f'{filename}.rpc{PROTO_H_EXTENSION}' |
| |
| |
| def _client_call(method: ProtoServiceMethod) -> str: |
| template_args = [] |
| |
| if method.client_streaming(): |
| template_args.append(method.request_type().nanopb_struct()) |
| |
| template_args.append(method.response_type().nanopb_struct()) |
| |
| return f'{client_call_type(method, "Nanopb")}<{", ".join(template_args)}>' |
| |
| |
| def _function(method: ProtoServiceMethod) -> str: |
| return f'{_client_call(method)} {method.name()}' |
| |
| |
| def _user_args(method: ProtoServiceMethod) -> Iterable[str]: |
| if not method.client_streaming(): |
| yield f'const {method.request_type().nanopb_struct()}& request' |
| |
| response = method.response_type().nanopb_struct() |
| |
| if method.server_streaming(): |
| yield f'::pw::Function<void(const {response}&)>&& on_next = nullptr' |
| yield '::pw::Function<void(::pw::Status)>&& on_completed = nullptr' |
| else: |
| yield (f'::pw::Function<void(const {response}&, ::pw::Status)>&& ' |
| 'on_completed = nullptr') |
| |
| yield '::pw::Function<void(::pw::Status)>&& on_error = nullptr' |
| |
| |
| class NanopbCodeGenerator(CodeGenerator): |
| """Generates an RPC service and client using the Nanopb API.""" |
| def name(self) -> str: |
| return 'nanopb' |
| |
| def method_union_name(self) -> str: |
| return 'NanopbMethodUnion' |
| |
| def includes(self, proto_file_name: str) -> Iterable[str]: |
| yield '#include "pw_rpc/nanopb/client_reader_writer.h"' |
| yield '#include "pw_rpc/nanopb/internal/method_union.h"' |
| yield '#include "pw_rpc/nanopb/server_reader_writer.h"' |
| |
| # Include the corresponding nanopb header file for this proto file, in |
| # which the file's messages and enums are generated. All other files |
| # imported from the .proto file are #included in there. |
| nanopb_header = _proto_filename_to_nanopb_header(proto_file_name) |
| yield f'#include "{nanopb_header}"' |
| |
| def service_aliases(self) -> None: |
| self.line('template <typename Response>') |
| self.line('using ServerWriter = ' |
| f'{RPC_NAMESPACE}::NanopbServerWriter<Response>;') |
| self.line('template <typename Request, typename Response>') |
| self.line('using ServerReader = ' |
| f'{RPC_NAMESPACE}::NanopbServerReader<Request, Response>;') |
| self.line('template <typename Request, typename Response>') |
| self.line( |
| 'using ServerReaderWriter = ' |
| f'{RPC_NAMESPACE}::NanopbServerReaderWriter<Request, Response>;') |
| |
| def method_descriptor(self, method: ProtoServiceMethod) -> None: |
| self.line(f'{RPC_NAMESPACE}::internal::' |
| f'GetNanopbOrRawMethodFor<&Implementation::{method.name()}, ' |
| f'{method.type().cc_enum()}, ' |
| f'{method.request_type().nanopb_struct()}, ' |
| f'{method.response_type().nanopb_struct()}>(') |
| with self.indent(4): |
| self.line(f'{get_id(method)}, // Hash of "{method.name()}"') |
| self.line(f'{_serde(method)}),') |
| |
| def client_member_function(self, method: ProtoServiceMethod) -> None: |
| """Outputs client code for a single RPC method.""" |
| |
| self.line(f'{_function(method)}(') |
| self.indented_list(*_user_args(method), end=') const {') |
| |
| with self.indent(): |
| client_call = _client_call(method) |
| base = 'Stream' if method.server_streaming() else 'Unary' |
| self.line(f'return {RPC_NAMESPACE}::internal::' |
| f'Nanopb{base}ResponseClientCall<' |
| f'{method.response_type().nanopb_struct()}>::' |
| f'Start<{client_call}>(') |
| |
| service_client = RPC_NAMESPACE + '::internal::ServiceClient' |
| |
| args = [ |
| f'{service_client}::client()', |
| f'{service_client}::channel_id()', |
| 'kServiceId', |
| get_id(method), |
| _serde(method), |
| ] |
| if method.server_streaming(): |
| args.append('std::move(on_next)') |
| |
| args.append('std::move(on_completed)') |
| args.append('std::move(on_error)') |
| |
| if not method.client_streaming(): |
| args.append('request') |
| |
| self.indented_list(*args, end=');') |
| |
| self.line('}') |
| |
| def client_static_function(self, method: ProtoServiceMethod) -> None: |
| self.line(f'static {_function(method)}(') |
| self.indented_list(f'{RPC_NAMESPACE}::Client& client', |
| 'uint32_t channel_id', |
| *_user_args(method), |
| end=') {') |
| |
| with self.indent(): |
| self.line(f'return Client(client, channel_id).{method.name()}(') |
| |
| args = [] |
| |
| if not method.client_streaming(): |
| args.append('request') |
| |
| if method.server_streaming(): |
| args.append('std::move(on_next)') |
| |
| self.indented_list(*args, |
| 'std::move(on_completed)', |
| 'std::move(on_error)', |
| end=');') |
| |
| self.line('}') |
| |
| def method_info_specialization(self, method: ProtoServiceMethod) -> None: |
| self.line() |
| self.line(f'using Request = {method.request_type().nanopb_struct()};') |
| self.line( |
| f'using Response = {method.response_type().nanopb_struct()};') |
| self.line() |
| self.line(f'static constexpr const {RPC_NAMESPACE}::internal::' |
| 'NanopbMethodSerde& serde() {') |
| with self.indent(): |
| self.line(f'return {_serde(method)};') |
| self.line('}') |
| |
| |
| class _CallbackFunction(NamedTuple): |
| """Represents a callback function parameter in a client RPC call.""" |
| |
| function_type: str |
| name: str |
| default_value: Optional[str] = None |
| |
| def __str__(self): |
| param = f'::pw::Function<{self.function_type}>&& {self.name}' |
| if self.default_value: |
| param += f' = {self.default_value}' |
| return param |
| |
| |
| class StubGenerator(codegen.StubGenerator): |
| """Generates Nanopb RPC stubs.""" |
| def unary_signature(self, method: ProtoServiceMethod, prefix: str) -> str: |
| return (f'::pw::Status {prefix}{method.name()}( ' |
| f'const {method.request_type().nanopb_struct()}& request, ' |
| f'{method.response_type().nanopb_struct()}& response)') |
| |
| def unary_stub(self, method: ProtoServiceMethod, |
| output: OutputFile) -> None: |
| output.write_line(codegen.STUB_REQUEST_TODO) |
| output.write_line('static_cast<void>(request);') |
| output.write_line(codegen.STUB_RESPONSE_TODO) |
| output.write_line('static_cast<void>(response);') |
| output.write_line('return ::pw::Status::Unimplemented();') |
| |
| def server_streaming_signature(self, method: ProtoServiceMethod, |
| prefix: str) -> str: |
| return ( |
| f'void {prefix}{method.name()}( ' |
| f'const {method.request_type().nanopb_struct()}& request, ' |
| f'ServerWriter<{method.response_type().nanopb_struct()}>& writer)') |
| |
| def client_streaming_signature(self, method: ProtoServiceMethod, |
| prefix: str) -> str: |
| return (f'void {prefix}{method.name()}( ' |
| f'ServerReader<{method.request_type().nanopb_struct()}, ' |
| f'{method.response_type().nanopb_struct()}>& reader)') |
| |
| def bidirectional_streaming_signature(self, method: ProtoServiceMethod, |
| prefix: str) -> str: |
| return (f'void {prefix}{method.name()}( ' |
| f'ServerReaderWriter<{method.request_type().nanopb_struct()}, ' |
| f'{method.response_type().nanopb_struct()}>& reader_writer)') |
| |
| |
| def process_proto_file(proto_file) -> Iterable[OutputFile]: |
| """Generates code for a single .proto file.""" |
| |
| _, package_root = build_node_tree(proto_file) |
| output_filename = _proto_filename_to_generated_header(proto_file.name) |
| generator = NanopbCodeGenerator(output_filename) |
| codegen.generate_package(proto_file, package_root, generator) |
| |
| codegen.package_stubs(package_root, generator, StubGenerator()) |
| |
| return [generator.output] |
