diff --git a/stream_interfaces.go b/stream_interfaces.go index 8b813529c0cc..0037fee0bd71 100644 --- a/stream_interfaces.go +++ b/stream_interfaces.go @@ -22,15 +22,35 @@ package grpc // request, many responses) RPC. It is generic over the type of the response // message. It is used in generated code. type ServerStreamingClient[Res any] interface { + // Recv receives the next response message from the server. The client may + // repeatedly call Recv to read messages from the response stream. If + // io.EOF is returned, the stream has terminated with an OK status. Any + // other error is compatible with the status package and indicates the + // RPC's status code and message. Recv() (*Res, error) + + // ClientStream is embedded to provide Context, Header, and Trailer + // functionality. No other methods in the ClientStream should be called + // directly. ClientStream } // ServerStreamingServer represents the server side of a server-streaming (one // request, many responses) RPC. It is generic over the type of the response // message. It is used in generated code. +// +// To terminate the response stream, return from the handler method and return +// an error from the status package, or use nil to indicate an OK status code. type ServerStreamingServer[Res any] interface { + // Send sends a response message to the client. The server handler may + // call Send multiple times to send multiple messages to the client. An + // error is returned if the stream was terminated unexpectedly, and the + // handler method should return, as the stream is no longer usable. Send(*Res) error + + // ServerStream is embedded to provide Context, SetHeader, SendHeader, and + // SetTrailer functionality. No other methods in the ServerStream should + // be called directly. ServerStream } @@ -39,8 +59,22 @@ type ServerStreamingServer[Res any] interface { // message stream and the type of the unary response message. It is used in // generated code. type ClientStreamingClient[Req any, Res any] interface { + // Send sends a request message to the server. The client may call Send + // multiple times to send multiple messages to the server. On error, Send + // aborts the stream. If the error was generated by the client, the status + // is returned directly. Otherwise, io.EOF is returned, and the status of + // the stream may be discovered using CloseAndRecv(). Send(*Req) error + + // CloseAndRecv closes the request stream and waits for the server's + // response. This method must be called once and only once after sending + // all request messages. Any error returned is implemented by the status + // package. CloseAndRecv() (*Res, error) + + // ClientStream is embedded to provide Context, Header, and Trailer + // functionality. No other methods in the ClientStream should be called + // directly. ClientStream } @@ -48,9 +82,28 @@ type ClientStreamingClient[Req any, Res any] interface { // requests, one response) RPC. It is generic over both the type of the request // message stream and the type of the unary response message. It is used in // generated code. +// +// To terminate the RPC, call SendAndClose and return nil from the method +// handler or do not call SendAndClose and return an error from the status +// package. type ClientStreamingServer[Req any, Res any] interface { + // Recv receives the next request message from the client. The server may + // repeatedly call Recv to read messages from the request stream. If + // io.EOF is returned, it indicates the client called CloseAndRecv on its + // ClientStreamingClient. Any other error indicates the stream was + // terminated unexpectedly, and the handler method should return, as the + // stream is no longer usable. Recv() (*Req, error) + + // SendAndClose sends a single response message to the client and closes + // the stream. This method must be called once and only once after all + // request messages have been processed. Recv should not be called after + // calling SendAndClose. SendAndClose(*Res) error + + // ServerStream is embedded to provide Context, SetHeader, SendHeader, and + // SetTrailer functionality. No other methods in the ServerStream should + // be called directly. ServerStream } @@ -59,8 +112,23 @@ type ClientStreamingServer[Req any, Res any] interface { // request message stream and the type of the response message stream. It is // used in generated code. type BidiStreamingClient[Req any, Res any] interface { + // Send sends a request message to the server. The client may call Send + // multiple times to send multiple messages to the server. On error, Send + // aborts the stream. If the error was generated by the client, the status + // is returned directly. Otherwise, io.EOF is returned, and the status of + // the stream may be discovered using Recv(). Send(*Req) error + + // Recv receives the next response message from the server. The client may + // repeatedly call Recv to read messages from the response stream. If + // io.EOF is returned, the stream has terminated with an OK status. Any + // other error is compatible with the status package and indicates the + // RPC's status code and message. Recv() (*Res, error) + + // ClientStream is embedded to provide Context, Header, Trailer, and + // CloseSend functionality. No other methods in the ClientStream should be + // called directly. ClientStream } @@ -68,9 +136,27 @@ type BidiStreamingClient[Req any, Res any] interface { // (many requests, many responses) RPC. It is generic over both the type of the // request message stream and the type of the response message stream. It is // used in generated code. +// +// To terminate the stream, return from the handler method and return +// an error from the status package, or use nil to indicate an OK status code. type BidiStreamingServer[Req any, Res any] interface { + // Recv receives the next request message from the client. The server may + // repeatedly call Recv to read messages from the request stream. If + // io.EOF is returned, it indicates the client called CloseSend on its + // BidiStreamingClient. Any other error indicates the stream was + // terminated unexpectedly, and the handler method should return, as the + // stream is no longer usable. Recv() (*Req, error) + + // Send sends a response message to the client. The server handler may + // call Send multiple times to send multiple messages to the client. An + // error is returned if the stream was terminated unexpectedly, and the + // handler method should return, as the stream is no longer usable. Send(*Res) error + + // ServerStream is embedded to provide Context, SetHeader, SendHeader, and + // SetTrailer functionality. No other methods in the ServerStream should + // be called directly. ServerStream }