RDMAPIImplInterface.h

Go to the documentation of this file.

/*
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 * RDMAPIImplInterface.h
 * The interface for an RDM API Implementation
 * Copyright (C) 2010 Simon Newton
 */

#ifndef INCLUDE_OLA_RDM_RDMAPIIMPLINTERFACE_H_
#define INCLUDE_OLA_RDM_RDMAPIIMPLINTERFACE_H_

#include <stdint.h>
#include <ola/rdm/UID.h>
#include <ola/Callback.h>
#include <ola/rdm/RDMEnums.h>
#include <ola/rdm/RDMResponseCodes.h>
#include <string>

namespace ola {
namespace rdm {

using std::string;


/*
 * Represents the state of a response and/or any error codes.
 *
 * RDM Handlers should first check for error being non-empty as this
 * represents an underlying transport error. Then the resonse_code
 * should be checked to catch invalid responses, timeouts etc. Finally, the
 * value of response_type should be checked against the rdm_response_type
 * codes.
 */
class ResponseStatus {
 public:
 string error; // Non empty if the RPC failed
 rdm_response_code response_code;
 uint8_t response_type; // The RDM response type
 uint8_t message_count; // Number of queued messages
 uint16_t m_param;
 bool set_command;
 uint16_t pid_value;

 // helper methods
 bool WasAcked() const {
 return (error.empty() && response_code == RDM_COMPLETED_OK &&
 response_type == RDM_ACK);
 }

 bool WasNacked() const {
 return (error.empty() && response_code == RDM_COMPLETED_OK &&
 response_type == RDM_NACK_REASON);
 }

 // Returns the NACK Reason code
 uint16_t NackReason() const { return m_param; }

 // Returns the time (in ms) to wait before re-trying
 unsigned int AckTimer() const { return 100 * m_param; }
};


/*
 * This is the interface for an RDMAPI implementation
 */
class RDMAPIImplInterface {
 public:
 virtual ~RDMAPIImplInterface() {}

 // args are the response type the param data
 typedef ola::SingleUseCallback2<void,
 const ResponseStatus&,
 const string&> rdm_callback;

 // args are response type, pid & param data
 typedef ola::SingleUseCallback3<void,
 const ResponseStatus&,
 uint16_t,
 const string&> rdm_pid_callback;

 // get command
 virtual bool RDMGet(rdm_callback *callback,
 unsigned int universe,
 const UID &uid,
 uint16_t sub_device,
 uint16_t pid,
 const uint8_t *data = NULL,
 unsigned int data_length = 0) = 0;

 // A version of Get that also returns the pid. This is used to deal with
 // queued messages
 virtual bool RDMGet(rdm_pid_callback *callback,
 unsigned int universe,
 const UID &uid,
 uint16_t sub_device,
 uint16_t pid,
 const uint8_t *data = NULL,
 unsigned int data_length = 0) = 0;

 // set command
 virtual bool RDMSet(rdm_callback *callback,
 unsigned int universe,
 const UID &uid,
 uint16_t sub_device,
 uint16_t pid,
 const uint8_t *data = NULL,
 unsigned int data_length = 0) = 0;
};
} // namespace rdm
} // namespace ola
#endif // INCLUDE_OLA_RDM_RDMAPIIMPLINTERFACE_H_