I/O object for server-side, server-streaming rpcs. More...

#include <agrpc/server_rpc.hpp>

Inheritance diagram for agrpc::ServerRPC< RequestServerStreaming, TraitsT, Executor >:

Collaboration diagram for agrpc::ServerRPC< RequestServerStreaming, TraitsT, Executor >:

Classes
struct	rebind_executor
	Rebind the ServerRPC to another executor. More...

Public Types
using	Request = RequestT
	The response message type.

using	Response = ResponseT
	The request message type.

using	Traits = TraitsT
	The traits type.

using	Ptr = agrpc::ServerRPCPtr< ServerRPC >
	ServerRPCPtr specialized on this type.

using	executor_type = Executor
	The executor type.

Public Member Functions
	ServerRPC ()=delete
	Deleted default constructor.

template<class CompletionToken = detail::DefaultCompletionTokenT<Executor>>
auto	write (const ResponseT &response, grpc::WriteOptions options, CompletionToken &&token=detail::DefaultCompletionTokenT< Executor >{})
	Send a message to the client. More...

template<class CompletionToken = detail::DefaultCompletionTokenT<Executor>>
auto	write (const ResponseT &response, CompletionToken &&token=detail::DefaultCompletionTokenT< Executor >{})
	Send a message to the client (default WriteOptions)

template<class CompletionToken = detail::DefaultCompletionTokenT<Executor>>
auto	write_and_finish (const ResponseT &response, grpc::WriteOptions options, const grpc::Status &status, CompletionToken &&token=detail::DefaultCompletionTokenT< Executor >{})
	Coalesce write and finish of this rpc. More...

template<class CompletionToken = detail::DefaultCompletionTokenT<Executor>>
auto	write_and_finish (const ResponseT &response, const grpc::Status &status, CompletionToken &&token=detail::DefaultCompletionTokenT< Executor >{})
	Coalesce write and finish of this rpc (default WriteOptions)

template<class CompletionToken = detail::DefaultCompletionTokenT<Executor>>
auto	finish (const grpc::Status &status, CompletionToken &&token=detail::DefaultCompletionTokenT< Executor >{})
	Finish this rpc. More...

auto	send_initial_metadata (CompletionToken &&token=detail::DefaultCompletionTokenT< Executor >{})
	Send initial metadata. More...

bool	is_done () const noexcept
	Is this rpc done? More...

auto	wait_for_done (CompletionToken &&token=detail::DefaultCompletionTokenT< Executor >{})
	Wait for done. More...

const executor_type &	get_executor () const noexcept
	Get the executor. More...

const executor_type &	get_scheduler () const noexcept
	Get the scheduler. More...

auto &	context ()
	Get the underlying `ServerContext`

const auto &	context () const
	Get the underlying `ServerContext` (const overload)

void	cancel () noexcept
	Cancel this RPC. More...

Static Public Member Functions
static constexpr std::string_view	service_name () noexcept
	Name of the gRPC service. More...

static constexpr std::string_view	method_name () noexcept
	Name of the gRPC method. More...

Static Public Attributes
static constexpr agrpc::ServerRPCType	TYPE = agrpc::ServerRPCType::SERVER_STREAMING
	The rpc type.

Detailed Description

template<class ServiceT, class RequestT, class ResponseT, detail::ServerServerStreamingRequest< ServiceT, RequestT, ResponseT > RequestServerStreaming, class TraitsT, class Executor>
class agrpc::ServerRPC< RequestServerStreaming, TraitsT, Executor >

I/O object for server-side, server-streaming rpcs.

Use one of the agrpc::register_ functions to set up request handling.

Example:

void server_rpc_server_streaming(agrpc::GrpcContext& grpc_context,
                                 example::v1::Example::AsyncService& service)
{
    using RPC = asio::use_awaitable_t<>::as_default_on_t<
        agrpc::ServerRPC<&example::v1::Example::AsyncService::RequestServerStreaming>>;
    agrpc::register_awaitable_rpc_handler<RPC>(
        grpc_context, service,
        [](RPC& rpc, RPC::Request& request) -> asio::awaitable<void>
        {
            RPC::Response response;
            for (int i{}; i != request.integer(); ++i)
            {
                response.set_integer(i);
                if (!co_await rpc.write(response))
                {
                    co_return;
                }
            }
            co_await rpc.finish(grpc::Status::OK);
        },
        asio::detached);
}

Based on .proto file:

syntax = "proto3";
 
package example.v1;
 
service Example {
  rpc ServerStreaming(Request) returns (stream Response) {}
 
  rpc ClientStreaming(stream Request) returns (Response) {}
 
  rpc BidirectionalStreaming(stream Request) returns (stream Response) {}
 
  rpc Unary(Request) returns (Response) {}
}
 
message Request {
  int32 integer = 1;
}
 
message Response {
  int32 integer = 1;
}

Template Parameters

RequestUnary	A pointer to the generated gRPC method.
Traits	A type used to customize this rpc. See `agrpc::DefaultServerRPCTraits`.
Executor	The executor type, must be capable of referring to a `agrpc::GrpcContext`.

Per-Operation Cancellation

(except wait_for_done) Terminal and partial. Cancellation is performed by invoking grpc::ServerContext::TryCancel. After successful cancellation no further operations should be started on the rpc. Operations are also cancelled when the deadline of the rpc has been reached.

Since: 2.7.0

Member Function Documentation

◆ service_name()

template<class ServiceT , class RequestT , class ResponseT , detail::ServerServerStreamingRequest< ServiceT, RequestT, ResponseT > RequestServerStreaming, class TraitsT , class Executor >

static constexpr std::string_view agrpc::ServerRPC< RequestServerStreaming, TraitsT, Executor >::service_name ( )

inlinestaticconstexprnoexcept

Name of the gRPC service.

Equal to the generated Service::service_full_name().

E.g. for the .proto schema

package example.v1;
 
service Example { ... }

the return value would be "example.v1.Example".

◆ method_name()

template<class ServiceT , class RequestT , class ResponseT , detail::ServerServerStreamingRequest< ServiceT, RequestT, ResponseT > RequestServerStreaming, class TraitsT , class Executor >

static constexpr std::string_view agrpc::ServerRPC< RequestServerStreaming, TraitsT, Executor >::method_name ( )

inlinestaticconstexprnoexcept

Name of the gRPC method.

E.g. for agrpc::ServerRPC<&example::Example::AsyncService::RequestMyMethod> the return value would be "MyMethod".

◆ write()

template<class ServiceT , class RequestT , class ResponseT , detail::ServerServerStreamingRequest< ServiceT, RequestT, ResponseT > RequestServerStreaming, class TraitsT , class Executor >

template<class CompletionToken = detail::DefaultCompletionTokenT<Executor>>

auto agrpc::ServerRPC< RequestServerStreaming, TraitsT, Executor >::write	(	const ResponseT &	response,
		grpc::WriteOptions	options,
		CompletionToken &&	token = `detail::DefaultCompletionTokenT<Executor>{}`
	)

inline

Send a message to the client.

Only one write may be outstanding at any given time.

GRPC does not take ownership or a reference to response, so it is safe to to deallocate once write returns, unless a deferred completion token like agrpc::use_sender or asio::deferred is used.

Parameters

token A completion token like asio::yield_context or agrpc::use_sender. The completion signature is void(bool). true means that the data/metadata/status/etc is going to go to the wire. If it is false, it is not going to the wire because the call is already dead (i.e., canceled, deadline expired, other side dropped the channel, etc).

◆ write_and_finish()

template<class ServiceT , class RequestT , class ResponseT , detail::ServerServerStreamingRequest< ServiceT, RequestT, ResponseT > RequestServerStreaming, class TraitsT , class Executor >

template<class CompletionToken = detail::DefaultCompletionTokenT<Executor>>

auto agrpc::ServerRPC< RequestServerStreaming, TraitsT, Executor >::write_and_finish	(	const ResponseT &	response,
		grpc::WriteOptions	options,
		const grpc::Status &	status,
		CompletionToken &&	token = `detail::DefaultCompletionTokenT<Executor>{}`
	)

inline

Coalesce write and finish of this rpc.

Write response and coalesce it with trailing metadata which contains status, using WriteOptions options.

write_and_finish is equivalent of performing write with WriteOptions.set_last_message() and finish in a single step.

GRPC does not take ownership or a reference to response and status, so it is safe to deallocate once write_and_finish returns, unless a deferred completion token like agrpc::use_sender or asio::deferred is used.

Implicit input parameter:

The ServerContext associated with the call is used for sending trailing (and initial) metadata to the client.

Note: Status must have an OK code.

Parameters

token A completion token like asio::yield_context or agrpc::use_sender. The completion signature is void(bool). true means that the data/metadata/status/etc is going to go to the wire. If it is false, it is not going to the wire because the call is already dead (i.e., canceled, deadline expired, other side dropped the channel, etc).

◆ finish()

template<class ServiceT , class RequestT , class ResponseT , detail::ServerServerStreamingRequest< ServiceT, RequestT, ResponseT > RequestServerStreaming, class TraitsT , class Executor >

template<class CompletionToken = detail::DefaultCompletionTokenT<Executor>>

auto agrpc::ServerRPC< RequestServerStreaming, TraitsT, Executor >::finish	(	const grpc::Status &	status,
		CompletionToken &&	token = `detail::DefaultCompletionTokenT<Executor>{}`
	)

inline

Finish this rpc.

Indicate that the stream is to be finished with a certain status code.

Should not be used concurrently with other operations and may only be called once.

This operation will end when the server has finished sending out initial metadata (if not sent already) and status, or if some failure occurred when trying to do so.

GRPC does not take ownership or a reference to status, so it is safe to to deallocate once finish returns, unless a deferred completion token like agrpc::use_sender or asio::deferred is used.

Parameters

token A completion token like asio::yield_context or agrpc::use_sender. The completion signature is void(bool). true means that the data/metadata/status/etc is going to go to the wire. If it is false, it is not going to the wire because the call is already dead (i.e., canceled, deadline expired, other side dropped the channel, etc).

◆ send_initial_metadata()

auto agrpc::detail::ServerRPCBase< grpc::ServerAsyncWriter< ResponseT > , TraitsT , Executor >::send_initial_metadata ( CompletionToken && token = detail::DefaultCompletionTokenT<Executor>{} )

inlineinherited

Send initial metadata.

Request notification of the sending of initial metadata to the client.

This call is optional, but if it is used, it cannot be used concurrently with or after the finish/finish_with_error method.

Parameters

token A completion token like asio::yield_context or agrpc::use_sender. The completion signature is void(bool). true means that the data/metadata/status/etc is going to go to the wire. If it is false, it is not going to the wire because the call is already dead (i.e., canceled, deadline expired, other side dropped the channel, etc).

◆ is_done()

bool agrpc::detail::ServerRPCNotifyWhenDoneMixin< IsNotifyWhenDone, grpc::ServerAsyncWriter< ResponseT > , Executor >::is_done ( ) const

inlinenoexceptinherited

Is this rpc done?

Only available if Traits contain NOTIFY_WHEN_DONE = true.

Returns true if NotifyWhenDone has fired which indicates the finish has been called or that the rpc is dead (i.e., canceled, deadline expired, other side dropped the channel, etc).

Thread-safe

◆ wait_for_done()

auto agrpc::detail::ServerRPCNotifyWhenDoneMixin< IsNotifyWhenDone, grpc::ServerAsyncWriter< ResponseT > , Executor >::wait_for_done ( CompletionToken && token = detail::DefaultCompletionTokenT<Executor>{} )

inlineinherited

Wait for done.

Only available if Traits contain NOTIFY_WHEN_DONE = true.

Request notification of the completion of this rpc, either due to calling finish or because the rpc is dead (i.e., canceled, deadline expired, other side dropped the channel, etc). rpc.context().IsCancelled() may only be called after this operation completes.

Cancelling this operation does not invoke grpc::ServerContext::TryCancel.

Parameters

token A completion token like asio::yield_context or agrpc::use_sender. The completion signature is void().

◆ get_executor()

template<class Executor >

const executor_type & agrpc::detail::RPCExecutorBase< Executor >::get_executor ( ) const

inlinenoexceptinherited

Get the executor.

Thread-safe

◆ get_scheduler()

template<class Executor >

const executor_type & agrpc::detail::RPCExecutorBase< Executor >::get_scheduler ( ) const

inlinenoexceptinherited

Get the scheduler.

Thread-safe

Since: 2.9.0

◆ cancel()

template<class Responder >

void agrpc::detail::ServerRPCContextBase< Responder >::cancel ( )

inlinenoexceptinherited

Cancel this RPC.

Effectively calls context().TryCancel().

Thread-safe

Classes

Public Types

Public Member Functions

Static Public Member Functions

Static Public Attributes

Detailed Description

Member Function Documentation

◆ service_name()

◆ method_name()

◆ write()

◆ write_and_finish()

◆ finish()

◆ send_initial_metadata()

◆ is_done()

◆ wait_for_done()

◆ get_executor()

◆ get_scheduler()

◆ cancel()