package grpc import ( "context" "io" "time" "github.com/nspcc-dev/neofs-api-go/v2/rpc/common" "google.golang.org/grpc" ) // Message represents raw gRPC message. type Message interface{} // MessageReadWriter is a component interface // for transmitting raw messages over gRPC protocol. type MessageReadWriter interface { // ReadMessage reads the next message from the remote server, // and writes it to the argument. ReadMessage(Message) error // WriteMessage sends message from argument to remote server. WriteMessage(Message) error // Closes the communication session with the remote server. // // All calls to send/receive messages must be done before closing. io.Closer } type streamWrapper struct { grpc.ClientStream timeout time.Duration cancel context.CancelFunc } func (w streamWrapper) ReadMessage(m Message) error { return w.withTimeout(func() error { return w.ClientStream.RecvMsg(m) }) } func (w streamWrapper) WriteMessage(m Message) error { return w.withTimeout(func() error { return w.ClientStream.SendMsg(m) }) } func (w *streamWrapper) Close() error { return w.withTimeout(w.ClientStream.CloseSend) } func (w *streamWrapper) withTimeout(closure func() error) error { ch := make(chan error, 1) go func() { ch <- closure() close(ch) }() select { case err := <-ch: return err case <-time.After(w.timeout): w.cancel() return context.DeadlineExceeded } } // Init initiates a messaging session within the RPC configured by options. func (c *Client) Init(info common.CallMethodInfo, opts ...CallOption) (MessageReadWriter, error) { prm := defaultCallParameters() for _, opt := range opts { opt(prm) } ctx, cancel := context.WithCancel(prm.ctx) stream, err := c.con.NewStream(ctx, &grpc.StreamDesc{ StreamName: info.Name, ServerStreams: info.ServerStream(), ClientStreams: info.ClientStream(), }, toMethodName(info)) if err != nil { cancel() return nil, err } return &streamWrapper{ ClientStream: stream, cancel: cancel, timeout: c.rwTimeout, }, nil }