func (p *pipeTransport) SendMessage(ctx context.Context, msg rpccapnp.Message) error {
if !p.startSend() {
return errClosed
}
defer p.finishSend()
buf, err := msg.Segment().Message().Marshal()
if err != nil {
return err
}
mm, err := capnp.Unmarshal(buf)
if err != nil {
return err
}
msg, err = rpccapnp.ReadRootMessage(mm)
if err != nil {
return err
}
select {
case p.w <- msg:
return nil
case <-ctx.Done():
return ctx.Err()
case <-p.finish:
return errClosed
case <-p.otherFin:
return errBrokenPipe
}
}
// copyRPCMessage clones an RPC packet.
func copyRPCMessage(m rpccapnp.Message) rpccapnp.Message {
mm := copyMessage(m.Segment().Message())
rpcMsg, err := rpccapnp.ReadRootMessage(mm)
if err != nil {
panic(err)
}
return rpcMsg
}
// handleCallMessage is run in the coordinate goroutine to handle a
// received call message. It mutates the capability table of its
// parameter.
func (c *Conn) handleCallMessage(m rpccapnp.Message) error {
mcall, err := m.Call()
if err != nil {
return err
}
mt, err := mcall.Target()
if err != nil {
return err
}
if mt.Which() != rpccapnp.MessageTarget_Which_importedCap && mt.Which() != rpccapnp.MessageTarget_Which_promisedAnswer {
um := newUnimplementedMessage(nil, m)
return c.sendMessage(um)
}
mparams, err := mcall.Params()
if err != nil {
return err
}
if err := c.populateMessageCapTable(mparams); err == errUnimplemented {
um := newUnimplementedMessage(nil, m)
return c.sendMessage(um)
} else if err != nil {
c.abort(err)
return err
}
ctx, cancel := c.newContext()
id := answerID(mcall.QuestionId())
a := c.answers.insert(id, cancel)
if a == nil {
// Question ID reused, error out.
c.abort(errQuestionReused)
return errQuestionReused
}
meth := capnp.Method{
InterfaceID: mcall.InterfaceId(),
MethodID: mcall.MethodId(),
}
paramContent, err := mparams.Content()
if err != nil {
return err
}
cl := &capnp.Call{
Ctx: ctx,
Method: meth,
Params: capnp.ToStruct(paramContent),
}
if err := c.routeCallMessage(a, mt, cl); err != nil {
msgs := a.reject(nil, err)
for _, m := range msgs {
if err := c.sendMessage(m); err != nil {
return err
}
}
return nil
}
return nil
}
func (c *Conn) handleDisembargoMessage(msg rpccapnp.Message) error {
d, err := msg.Disembargo()
if err != nil {
return err
}
dtarget, err := d.Target()
if err != nil {
return err
}
switch d.Context().Which() {
case rpccapnp.Disembargo_context_Which_senderLoopback:
id := embargoID(d.Context().SenderLoopback())
if dtarget.Which() != rpccapnp.MessageTarget_Which_promisedAnswer {
return errDisembargoNonImport
}
dpa, err := dtarget.PromisedAnswer()
if err != nil {
return err
}
aid := answerID(dpa.QuestionId())
a := c.answers.get(aid)
if a == nil {
return errDisembargoMissingAnswer
}
dtrans, err := dpa.Transform()
if err != nil {
return err
}
transform := promisedAnswerOpsToTransform(dtrans)
queued, err := a.queueDisembargo(transform, id, dtarget)
if err != nil {
return err
}
if !queued {
// There's nothing to embargo; everything's been delivered.
resp := newDisembargoMessage(nil, rpccapnp.Disembargo_context_Which_receiverLoopback, id)
rd, _ := resp.Disembargo()
if err := rd.SetTarget(dtarget); err != nil {
return err
}
c.sendMessage(resp)
}
case rpccapnp.Disembargo_context_Which_receiverLoopback:
id := embargoID(d.Context().ReceiverLoopback())
c.embargoes.disembargo(id)
default:
um := newUnimplementedMessage(nil, msg)
c.sendMessage(um)
}
return nil
}
func (s *streamTransport) SendMessage(ctx context.Context, msg rpccapnp.Message) error {
s.wbuf.Reset()
if err := s.enc.Encode(msg.Segment().Message()); err != nil {
return err
}
if s.deadline != nil {
// TODO(light): log errors
if d, ok := ctx.Deadline(); ok {
s.deadline.SetWriteDeadline(d)
} else {
s.deadline.SetWriteDeadline(time.Time{})
}
}
_, err := s.rwc.Write(s.wbuf.Bytes())
return err
}
func formatMsg(w io.Writer, m rpccapnp.Message) {
switch m.Which() {
case rpccapnp.Message_Which_unimplemented:
fmt.Fprint(w, "unimplemented")
case rpccapnp.Message_Which_abort:
mabort, _ := m.Abort()
reason, _ := mabort.Reason()
fmt.Fprintf(w, "abort type=%v: %s", mabort.Type(), reason)
case rpccapnp.Message_Which_bootstrap:
mboot, _ := m.Bootstrap()
fmt.Fprintf(w, "bootstrap id=%d", mboot.QuestionId())
case rpccapnp.Message_Which_call:
c, _ := m.Call()
fmt.Fprintf(w, "call id=%d target=<", c.QuestionId())
tgt, _ := c.Target()
formatMessageTarget(w, tgt)
fmt.Fprintf(w, "> @%#x/@%d", c.InterfaceId(), c.MethodId())
case rpccapnp.Message_Which_return:
r, _ := m.Return()
fmt.Fprintf(w, "return id=%d", r.AnswerId())
if r.ReleaseParamCaps() {
fmt.Fprint(w, " releaseParamCaps")
}
switch r.Which() {
case rpccapnp.Return_Which_results:
case rpccapnp.Return_Which_exception:
exc, _ := r.Exception()
reason, _ := exc.Reason()
fmt.Fprintf(w, ", exception type=%v: %s", exc.Type(), reason)
case rpccapnp.Return_Which_canceled:
fmt.Fprint(w, ", canceled")
case rpccapnp.Return_Which_resultsSentElsewhere:
fmt.Fprint(w, ", results sent elsewhere")
case rpccapnp.Return_Which_takeFromOtherQuestion:
fmt.Fprint(w, ", results sent elsewhere")
case rpccapnp.Return_Which_acceptFromThirdParty:
fmt.Fprint(w, ", accept from third party")
default:
fmt.Fprintf(w, ", UNKNOWN RESULT which=%v", r.Which())
}
case rpccapnp.Message_Which_finish:
fin, _ := m.Finish()
fmt.Fprintf(w, "finish id=%d", fin.QuestionId())
if fin.ReleaseResultCaps() {
fmt.Fprint(w, " releaseResultCaps")
}
case rpccapnp.Message_Which_resolve:
r, _ := m.Resolve()
fmt.Fprintf(w, "resolve id=%d ", r.PromiseId())
switch r.Which() {
case rpccapnp.Resolve_Which_cap:
fmt.Fprint(w, "capability=")
c, _ := r.Cap()
formatCapDescriptor(w, c)
case rpccapnp.Resolve_Which_exception:
exc, _ := r.Exception()
reason, _ := exc.Reason()
fmt.Fprintf(w, "exception type=%v: %s", exc.Type(), reason)
default:
fmt.Fprintf(w, "UNKNOWN RESOLUTION which=%v", r.Which())
}
case rpccapnp.Message_Which_release:
rel, _ := m.Release()
fmt.Fprintf(w, "release id=%d by %d", rel.Id(), rel.ReferenceCount())
case rpccapnp.Message_Which_disembargo:
de, _ := m.Disembargo()
tgt, _ := de.Target()
fmt.Fprint(w, "disembargo <")
formatMessageTarget(w, tgt)
fmt.Fprint(w, "> ")
dc := de.Context()
switch dc.Which() {
case rpccapnp.Disembargo_context_Which_senderLoopback:
fmt.Fprintf(w, "sender loopback id=%d", dc.SenderLoopback())
case rpccapnp.Disembargo_context_Which_receiverLoopback:
fmt.Fprintf(w, "receiver loopback id=%d", dc.ReceiverLoopback())
case rpccapnp.Disembargo_context_Which_accept:
fmt.Fprint(w, "accept")
case rpccapnp.Disembargo_context_Which_provide:
fmt.Fprintf(w, "provide id=%d", dc.Provide())
default:
fmt.Fprintf(w, "UNKNOWN CONTEXT which=%v", dc.Which())
}
case rpccapnp.Message_Which_obsoleteSave:
fmt.Fprint(w, "save")
case rpccapnp.Message_Which_obsoleteDelete:
fmt.Fprint(w, "delete")
case rpccapnp.Message_Which_provide:
prov, _ := m.Provide()
tgt, _ := prov.Target()
fmt.Fprintf(w, "provide id=%d <", prov.QuestionId())
formatMessageTarget(w, tgt)
fmt.Fprint(w, ">")
case rpccapnp.Message_Which_accept:
acc, _ := m.Accept()
fmt.Fprintf(w, "accept id=%d", acc.QuestionId())
if acc.Embargo() {
fmt.Fprint(w, " with embargo")
}
case rpccapnp.Message_Which_join:
join, _ := m.Join()
tgt, _ := join.Target()
fmt.Fprintf(w, "join id=%d <", join.QuestionId())
formatMessageTarget(w, tgt)
fmt.Fprint(w, ">")
default:
fmt.Fprintf(w, "UNKNOWN MESSAGE which=%v", m.Which())
}
}
// handleReturnMessage is run in the coordinate goroutine.
func (c *Conn) handleReturnMessage(m rpccapnp.Message) error {
ret, err := m.Return()
if err != nil {
return err
}
id := questionID(ret.AnswerId())
q := c.questions.pop(id)
if q == nil {
return fmt.Errorf("received return for unknown question id=%d", id)
}
if ret.ReleaseParamCaps() {
c.exports.releaseList(q.paramCaps)
}
if _, _, _, resolved := q.peek(); resolved {
// If the question was already resolved, that means it was canceled,
// in which case we already sent the finish message.
return nil
}
releaseResultCaps := true
switch ret.Which() {
case rpccapnp.Return_Which_results:
releaseResultCaps = false
results, err := ret.Results()
if err != nil {
return err
}
if err := c.populateMessageCapTable(results); err == errUnimplemented {
um := newUnimplementedMessage(nil, m)
c.sendMessage(um)
return errUnimplemented
} else if err != nil {
c.abort(err)
return err
}
content, err := results.Content()
if err != nil {
return err
}
disembargoes := q.fulfill(content, c.embargoes.new)
for _, d := range disembargoes {
if err := c.sendMessage(d); err != nil {
// shutdown
return nil
}
}
case rpccapnp.Return_Which_exception:
exc, err := ret.Exception()
if err != nil {
return err
}
e := error(Exception{exc})
if q.method != nil {
e = &capnp.MethodError{
Method: q.method,
Err: e,
}
} else {
e = bootstrapError{e}
}
q.reject(questionResolved, e)
case rpccapnp.Return_Which_canceled:
err := &questionError{
id: id,
method: q.method,
err: fmt.Errorf("receiver reported canceled"),
}
log.Println(err)
q.reject(questionResolved, err)
return nil
default:
um := newUnimplementedMessage(nil, m)
c.sendMessage(um)
return errUnimplemented
}
fin := newFinishMessage(nil, id, releaseResultCaps)
c.sendMessage(fin)
return nil
}
// handleMessage is run in the coordinate goroutine.
func (c *Conn) handleMessage(m rpccapnp.Message) {
switch m.Which() {
case rpccapnp.Message_Which_unimplemented:
// no-op for now to avoid feedback loop
case rpccapnp.Message_Which_abort:
ma, err := m.Abort()
if err != nil {
log.Println("rpc: decode abort:", err)
// Keep going, since we're trying to abort anyway.
}
a := Abort{ma}
log.Print(a)
c.manager.shutdown(a)
case rpccapnp.Message_Which_return:
if err := c.handleReturnMessage(m); err != nil {
log.Println("rpc: handle return:", err)
}
case rpccapnp.Message_Which_finish:
// TODO(light): what if answers never had this ID?
// TODO(light): return if cancelled
mfin, err := m.Finish()
if err != nil {
log.Println("rpc: decode finish:", err)
return
}
id := answerID(mfin.QuestionId())
a := c.answers.pop(id)
a.cancel()
if mfin.ReleaseResultCaps() {
c.exports.releaseList(a.resultCaps)
}
case rpccapnp.Message_Which_bootstrap:
boot, err := m.Bootstrap()
if err != nil {
log.Println("rpc: decode bootstrap:", err)
return
}
id := answerID(boot.QuestionId())
if err := c.handleBootstrapMessage(id); err != nil {
log.Println("rpc: handle bootstrap:", err)
}
case rpccapnp.Message_Which_call:
if err := c.handleCallMessage(m); err != nil {
log.Println("rpc: handle call:", err)
}
case rpccapnp.Message_Which_release:
rel, err := m.Release()
if err != nil {
log.Println("rpc: decode release:", err)
return
}
id := exportID(rel.Id())
refs := int(rel.ReferenceCount())
c.exports.release(id, refs)
case rpccapnp.Message_Which_disembargo:
if err := c.handleDisembargoMessage(m); err != nil {
// Any failure in a disembargo is a protocol violation.
c.abort(err)
}
default:
log.Printf("rpc: received unimplemented message, which = %v", m.Which())
um := newUnimplementedMessage(nil, m)
c.sendMessage(um)
}
}
