TransferReceiver::ResultCode TransferReceiver::receive(const RxFrame& frame, TransferBufferAccessor& tba)
{
// Transfer timestamps are derived from the first frame
if (frame.isFirst())
{
this_transfer_ts_ = frame.getMonotonicTimestamp();
first_frame_ts_ = frame.getUtcTimestamp();
}
if (frame.isFirst() && frame.isLast())
{
tba.remove();
updateTransferTimings();
prepareForNextTransfer();
this_transfer_crc_ = 0; // SFT has no CRC
return ResultSingleFrame;
}
// Payload write
ITransferBuffer* buf = tba.access();
if (buf == NULL)
{
buf = tba.create();
}
if (buf == NULL)
{
UAVCAN_TRACE("TransferReceiver", "Failed to access the buffer, %s", frame.toString().c_str());
prepareForNextTransfer();
registerError();
return ResultNotComplete;
}
if (!writePayload(frame, *buf))
{
UAVCAN_TRACE("TransferReceiver", "Payload write failed, %s", frame.toString().c_str());
tba.remove();
prepareForNextTransfer();
registerError();
return ResultNotComplete;
}
next_frame_index_++;
if (frame.isLast())
{
updateTransferTimings();
prepareForNextTransfer();
return ResultComplete;
}
return ResultNotComplete;
}
TransferReceiver::ResultCode TransferReceiver::addFrame(const RxFrame& frame, TransferBufferAccessor& tba)
{
if ((frame.getMonotonicTimestamp().isZero()) ||
(frame.getMonotonicTimestamp() < prev_transfer_ts_) ||
(frame.getMonotonicTimestamp() < this_transfer_ts_))
{
return ResultNotComplete;
}
const bool not_initialized = !isInitialized();
const bool receiver_timed_out = isTimedOut(frame.getMonotonicTimestamp());
const bool same_iface = frame.getIfaceIndex() == iface_index_;
const bool first_fame = frame.isFirst();
const TidRelation tid_rel = getTidRelation(frame);
const bool iface_timed_out =
(frame.getMonotonicTimestamp() - this_transfer_ts_).toUSec() > (int64_t(transfer_interval_usec_) * 2);
// FSM, the hard way
const bool need_restart =
(not_initialized) ||
(receiver_timed_out) ||
(same_iface && first_fame && (tid_rel == TidFuture)) ||
(iface_timed_out && first_fame && (tid_rel == TidFuture));
if (need_restart)
{
const bool error = !not_initialized && !receiver_timed_out;
if (error)
{
registerError();
}
UAVCAN_TRACE("TransferReceiver",
"Restart [not_inited=%i, iface_timeout=%i, recv_timeout=%i, same_iface=%i, first_frame=%i, tid_rel=%i], %s",
int(not_initialized), int(iface_timed_out), int(receiver_timed_out), int(same_iface),
int(first_fame), int(tid_rel), frame.toString().c_str());
tba.remove();
iface_index_ = frame.getIfaceIndex();
tid_ = frame.getTransferID();
next_frame_index_ = 0;
buffer_write_pos_ = 0;
this_transfer_crc_ = 0;
if (!first_fame)
{
tid_.increment();
return ResultNotComplete;
}
}
if (!validate(frame))
{
return ResultNotComplete;
}
return receive(frame, tba);
}