Example #1
0
func (d *Diagnostics) getDiagnosticFromPeer(ctx context.Context, p peer.ID, pmes *pb.Message) (<-chan *DiagInfo, error) {
	s, err := d.host.NewStream(ProtocolDiag, p)
	if err != nil {
		return nil, err
	}

	cr := ctxio.NewReader(ctx, s) // ok to use. we defer close stream in this func
	cw := ctxio.NewWriter(ctx, s) // ok to use. we defer close stream in this func
	r := ggio.NewDelimitedReader(cr, inet.MessageSizeMax)
	w := ggio.NewDelimitedWriter(cw)

	start := time.Now()

	if err := w.WriteMsg(pmes); err != nil {
		return nil, err
	}

	out := make(chan *DiagInfo)
	go func() {

		defer func() {
			close(out)
			s.Close()
			rtt := time.Since(start)
			log.Infof("diagnostic request took: %s", rtt.String())
		}()

		for {
			rpmes := new(pb.Message)
			if err := r.ReadMsg(rpmes); err != nil {
				log.Debugf("Error reading diagnostic from stream: %s", err)
				return
			}
			if rpmes == nil {
				log.Debug("Got no response back from diag request.")
				return
			}

			di, err := decodeDiagJson(rpmes.GetData())
			if err != nil {
				log.Debug(err)
				return
			}

			select {
			case out <- di:
			case <-ctx.Done():
				return
			}
		}

	}()

	return out, nil
}