def _generate_code_for_client(service: ProtoService, root: ProtoNode,
output: OutputFile) -> None:
"""Outputs client code for an RPC service."""
output.write_line('namespace nanopb {')
class_name = f'{service.cpp_namespace(root)}Client'
output.write_line(f'\nclass {class_name} {{')
output.write_line(' public:')
with output.indent():
output.write_line('template <typename T>')
output.write_line(
f'using NanopbClientCall = {RPC_NAMESPACE}::NanopbClientCall<T>;')
output.write_line('')
output.write_line(f'{class_name}() = delete;')
for method in service.methods():
_generate_code_for_client_method(method, output)
service_name_hash = pw_rpc.ids.calculate(service.proto_path())
output.write_line('\n private:')
with output.indent():
output.write_line(f'// Hash of "{service.proto_path()}".')
output.write_line(
f'static constexpr uint32_t kServiceId = 0x{service_name_hash:08x};'
)
output.write_line('};')
output.write_line('\n} // namespace nanopb\n')
def _generate_service_stub(service: ProtoService, output: OutputFile,
unary_stub: StubFunction,
server_streaming_stub: StubFunction) -> None:
output.write_line()
output.write_line(
f'class {service.name()} '
f': public generated::{service.name()}<{service.name()}> {{')
output.write_line(' public:')
with output.indent():
blank_line = False
for method in service.methods():
if blank_line:
output.write_line()
else:
blank_line = True
if method.type() is ProtoServiceMethod.Type.UNARY:
unary_stub(method, output)
elif method.type() is ProtoServiceMethod.Type.SERVER_STREAMING:
server_streaming_stub(method, output)
else:
raise NotImplementedError(
'Client and bidirectional streaming not yet implemented')
output.write_line('};\n')
def _method_lookup_table(service: ProtoService, output: OutputFile) -> None:
"""Generates array of method IDs for looking up methods at compile time."""
output.write_line('static constexpr std::array<uint32_t, '
f'{len(service.methods())}> kMethodIds = {{')
with output.indent(4):
for method in service.methods():
method_id = pw_rpc.ids.calculate(method.name())
output.write_line(
f'0x{method_id:08x}, // Hash of "{method.name()}"')
output.write_line('};\n')
def _generate_service_stubs(service: ProtoService, output: OutputFile,
stub_generator: StubGenerator) -> None:
output.write_line(f'// Method definitions for {service.proto_path()}.')
blank_line = False
for method in service.methods():
if blank_line:
output.write_line()
else:
blank_line = True
signature, stub = _select_stub_methods(stub_generator, method)
output.write_line(signature(method, f'{service.name()}::') + ' {')
with output.indent():
stub(method, output)
output.write_line('}')
def _generate_service_class(service: ProtoService, output: OutputFile,
stub_generator: StubGenerator) -> None:
output.write_line(f'// Implementation class for {service.proto_path()}.')
output.write_line(
f'class {service.name()} '
f': public generated::{service.name()}<{service.name()}> {{')
output.write_line(' public:')
with output.indent():
blank_line = False
for method in service.methods():
if blank_line:
output.write_line()
else:
blank_line = True
signature, _ = _select_stub_methods(stub_generator, method)
output.write_line(signature(method, '') + ';')
output.write_line('};\n')
def service_class(service: ProtoService, root: ProtoNode, output: OutputFile,
server_writer_alias: ServerWriterGenerator,
method_union: str,
method_descriptor: MethodGenerator) -> None:
"""Generates a C++ derived class for a nanopb RPC service."""
output.write_line('namespace generated {')
base_class = f'{RPC_NAMESPACE}::Service'
output.write_line('\ntemplate <typename Implementation>')
output.write_line(
f'class {service.cpp_namespace(root)} : public {base_class} {{')
output.write_line(' public:')
with output.indent():
output.write_line(
f'using ServerContext = {RPC_NAMESPACE}::ServerContext;')
server_writer_alias(output)
output.write_line()
output.write_line(f'constexpr {service.name()}()')
output.write_line(f' : {base_class}(kServiceId, kMethods) {{}}')
output.write_line()
output.write_line(
f'{service.name()}(const {service.name()}&) = delete;')
output.write_line(f'{service.name()}& operator='
f'(const {service.name()}&) = delete;')
output.write_line()
output.write_line(f'static constexpr const char* name() '
f'{{ return "{service.name()}"; }}')
output.write_line()
output.write_line(
'// Used by MethodLookup to identify the generated service base.')
output.write_line(
'constexpr void _PwRpcInternalGeneratedBase() const {}')
service_name_hash = pw_rpc.ids.calculate(service.proto_path())
output.write_line('\n private:')
with output.indent():
output.write_line('friend class ::pw::rpc::internal::MethodLookup;\n')
output.write_line(f'// Hash of "{service.proto_path()}".')
output.write_line(
f'static constexpr uint32_t kServiceId = 0x{service_name_hash:08x};'
)
output.write_line()
# Generate the method table
output.write_line('static constexpr std::array<'
f'{RPC_NAMESPACE}::internal::{method_union},'
f' {len(service.methods())}> kMethods = {{')
with output.indent(4):
for method in service.methods():
method_descriptor(method, pw_rpc.ids.calculate(method.name()),
output)
output.write_line('};\n')
# Generate the method lookup table
_method_lookup_table(service, output)
output.write_line('};')
output.write_line('\n} // namespace generated\n')