TractionClient.hxx

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#ifndef _OPENLCB_TRACTIONCLIENT_HXX_
#define _OPENLCB_TRACTIONCLIENT_HXX_
 
#include "openlcb/If.hxx"
#include "openlcb/Defs.hxx"
 
namespace openlcb
{
 
class TractionResponseHandler : public IncomingMessageStateFlow
{
public:
    TractionResponseHandler(openlcb::If *iface,
                            openlcb::Node *local_node)
        : IncomingMessageStateFlow(iface)
        , expectedDst_(local_node)
        , trigger_(nullptr)
        , response_(nullptr)
    {
    }
 
    void wait_for_response(NodeHandle target_node, uint8_t expected_type,
                           ::Timer *trigger)
    {
        response_ = nullptr;
        expectedSrc_ = target_node;
        expectedType_ = expected_type;
        trigger_ = trigger;
        start_listening();
    }
 
    Buffer<GenMessage> *response()
    {
        return response_;
    }
 
    void wait_timeout()
    {
        if (trigger_)
        {
            trigger_ = nullptr;
            stop_listening();
        }
    }
 
private:
    void start_listening()
    {
        iface()->dispatcher()->register_handler(
            this, openlcb::Defs::MTI_TRACTION_CONTROL_REPLY,
            openlcb::Defs::MTI_EXACT);
    }
 
    void stop_listening()
    {
        iface()->dispatcher()->unregister_handler(
            this, openlcb::Defs::MTI_TRACTION_CONTROL_REPLY,
            openlcb::Defs::MTI_EXACT);
    }
 
    Action entry() OVERRIDE
    {
        LOG(VERBOSE, "response came");
 
        if (!trigger_)
        {
            // We already matched -- drop all packets to the floor.
            LOG(VERBOSE, "no trigger");
            return release_and_exit();
        }
        if (nmsg()->dstNode != expectedDst_) {
            LOG(VERBOSE, "dst not match");
            return release_and_exit();
        }
        if (expectedSrc_.id && nmsg()->src.id)
        {
            if (expectedSrc_.id != nmsg()->src.id)
            {
                LOG(VERBOSE, "src.id not match");
                return release_and_exit();
            }
        }
        else if (expectedSrc_.alias && nmsg()->src.alias)
        {
            if (expectedSrc_.alias != nmsg()->src.alias)
            {
                LOG(VERBOSE, "src.alias not match");
                return release_and_exit();
            }
        }
        else
        {
            DIE("Unable to decide whether the incoming response is coming from "
                "the right place.");
        }
        // Now: message is from the right source node, to the right destination
        // node.
        if (nmsg()->payload.size() < 1) {
            LOG(VERBOSE, "no payload");
            return release_and_exit();
        }
        if (nmsg()->payload[0] != expectedType_) {
            LOG(VERBOSE, "payload type no match");
            return release_and_exit();
        }
        // Now: we matched!
        stop_listening();
        response_ = transfer_message();
        trigger_->trigger();
        trigger_ = nullptr;
        return exit();
    }
 
    openlcb::NodeHandle expectedSrc_;
    openlcb::Node *expectedDst_;
    // First byte of the response message.
    uint8_t expectedType_;
    ::Timer *trigger_;
    Buffer<GenMessage> *response_;
};
 
} // namespace openlcb
 
#endif // _OPENLCB_TRACTIONCLIENT_HXX_