Exemple #1
0
func responseFromRequest(req Request, body interface{}) Response {
	rsp := NewResponse()
	rsp.SetId(req.Id())
	if body != nil {
		rsp.SetBody(body)

		ct := req.Headers()[marshaling.AcceptHeader]
		marshaler := marshaling.Marshaler(ct)
		if marshaler == nil { // Fall back to JSON
			marshaler = marshaling.Marshaler(marshaling.JSONContentType)
		}
		if marshaler == nil {
			log.Error(req, "[Mercury] No marshaler for response %s: %s", rsp.Id(), ct)
		} else if err := marshaler.MarshalBody(rsp); err != nil {
			log.Error(req, "[Mercury] Failed to marshal response %s: %v", rsp.Id(), err)
		}
	}
	return rsp
}
Exemple #2
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// ErrorResponse constructs a response for the given request, with the given error as its contents. Mercury clients
// know how to unmarshal these errors.
func ErrorResponse(req mercury.Request, err error) mercury.Response {
	rsp := req.Response(nil)
	var terr *terrors.Error
	if err != nil {
		terr = terrors.Wrap(err, nil).(*terrors.Error)
	}
	rsp.SetBody(terrors.Marshal(terr))
	if err := tmsg.JSONMarshaler().MarshalBody(rsp); err != nil {
		log.Error(req, "[Mercury:Server] Failed to marshal error response: %v", err)
		return nil // Not much we can do here
	}
	rsp.SetIsError(true)
	return rsp
}
Exemple #3
0
// performCall executes a single Call, unmarshals the response (if there is a response proto), and pushes the updted
// clientCall down the response channel
func (c *client) performCall(call clientCall, middleware []ClientMiddleware, trans transport.Transport,
	timeout time.Duration, completion chan<- clientCall) {

	req := call.req

	// Ensure we have a request ID before the request middleware is executed
	if id := req.Id(); id == "" {
		_uuid, err := uuid.NewV4()
		if err != nil {
			log.Error(call.req, "[Mercury:Client] Failed to generate request uuid: %v", err)
			call.err = terrors.Wrap(err, nil).(*terrors.Error)
			completion <- call
			return
		}
		req.SetId(_uuid.String())
	}

	// Apply request middleware
	for _, md := range middleware {
		req = md.ProcessClientRequest(req)
	}

	rsp_, err := trans.Send(req, timeout)
	if err != nil {
		call.err = terrors.Wrap(err, nil).(*terrors.Error)
	} else if rsp_ != nil {
		rsp := mercury.FromTyphonResponse(rsp_)

		// For error responses, unmarshal the error, leaving the call's response nil
		if rsp.IsError() {
			errRsp := rsp.Copy()
			if unmarshalErr := c.unmarshaler(rsp, &tperrors.Error{}).UnmarshalPayload(errRsp); unmarshalErr != nil {
				call.err = terrors.WrapWithCode(unmarshalErr, nil, terrors.ErrBadResponse).(*terrors.Error)
			} else {
				err := errRsp.Body().(*tperrors.Error)
				call.err = terrors.Unmarshal(err)
			}

			// Set the response Body to a nil – but typed – interface to avoid type conversion panics if Body
			// properties are accessed in spite of the error
			// Relevant: http://golang.org/doc/faq#nil_error
			if call.rspProto != nil {
				bodyT := reflect.TypeOf(call.rspProto)
				rsp.SetBody(reflect.New(bodyT.Elem()).Interface())
			}

		} else if call.rspProto != nil {
			rsp.SetBody(call.rspProto)
			if err := c.unmarshaler(rsp, call.rspProto).UnmarshalPayload(rsp); err != nil {
				call.err = terrors.WrapWithCode(err, nil, terrors.ErrBadResponse).(*terrors.Error)
			}
		}

		call.rsp = rsp
	}

	// Apply response/error middleware (in reverse order)
	for i := len(middleware) - 1; i >= 0; i-- {
		mw := middleware[i]
		if call.err != nil {
			mw.ProcessClientError(call.err, call.req)
		} else {
			call.rsp = mw.ProcessClientResponse(call.rsp, call.req)
		}
	}

	completion <- call
}