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dns.h

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/*
Object Oriented Mobile Robot Model (OOMRM) C++  Library Copyright (C) 2007  Derek Jones

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


 $Id: dns.h,v 1.1 2007/06/10 23:15:00 derek Exp $

Implementation Notes:
  Have a transmit method that will resolve device name to Jaus address.

   The only drawback to this method is the instances have to be specified whereas
usually I let them simply increment forming top of stack.  Because of this, the
search time for instance in object_list will increase as will always have to search
the whole instance array (unless already found).

  The system name of "self" can be used instead of real system name. 
 If so, it defaults to the current system name.  

NOTE: No system can use name of "self".
system name.  For example,
transmit("self.led.green",msg); 

  Jstatus.header(6, Set_Binary_Status_Message, NO_ACKNOWLEDGE, NORMAL_DATA_PACKET,
         1, 1, Binary_Status_Component, iRED_LED,
         1, 1, Binary_Status_Component, iRED_LED);

now becomes:
  Jstatus.header(6, Set_Binary_Status_Message, NO_ACKNOWLEDGE, NORMAL_DATA_PACKET,"self.led.red");

  Three possible implementations:
1.  Jstatus.header("mrm.led.red"); // send intranode message if source ommitted.
 or Jstatus.header("host.com","mrm.led.red"); for both addresses.
Advantage: do not need to need any internal constants, although arguably the device name is a type of constant that
           serves as a global header file, but perhaps more flexible.
           Another advantage from application developer perspective is you don't need to even know
           which system ID or JAUS component implements it.  The translation to the component/instance is done in the DSN configuration file.
           Also, a vendor can implement new experimental components and simply give application the name of the 
           new device.  Its implementation to component instance can change without needing to change application that uses it..
Disadvantage: more processing to translate device name to address.
              Another disadvantage for some components is the application developer needs to know the device names
              rather than just know "Local_Waypoint_Driver".  If the waypoint driver name is "mrm.driver".

NOTE: suggest making so if you ommit the last parameter, then it defaults to any instance defined.
NOTE: Although wayoint driver instance name can even be standardized based upon implementation methodology.
      For instance, no obstacle driver can be "clear" thus if it is supported, you can know the name
      "mrm.driver.clear".
2.   Jstatus.header(Binary_Status_Component,iRED_LED);
Advantage: quicker 
Disadvantage: Need to know all the internal values of how it is implemented component/instances.

mrm.led.red,2.1.47.1
mrm.led.green,2.1.47.2
mrm.io.port_e0,2.1.47.3
mrm.io.port_e1,2.1.47.4
mrm.io.port_e2,2.1.47.5
mrm.io.port_e3,2.1.47.6
mrm.io.port_e4,2.1.47.7
mrm.io.port_e5,2.1.47.8
mrm.io.port_e6,2.1.47.9
mrm.io.port_e7,2.1.47.10
mrm.io.port_f0,2.1.47.11
mrm.io.port_f1,2.1.47.12
mrm.io.port_f2,2.1.47.13
mrm.io.port_f3,2.1.47.14
mrm.io.port_f4,2.1.47.15
mrm.io.port_f5,2.1.47.16
mrm.io.port_f6,2.1.47.17
mrm.io.port_f7,2.1.47.18
host.led.red,1.1.47.1
host.led.green,1.1.47.2

*/
#ifndef _DeviceNameService_H
#define _DeviceNameService_H

#include <types.h>
#include <jaus/jaus_message.h>

class DeviceNameService 
{
public:
  DeviceNameService(void);
  // configure name of system/subsystem and corresponding address.
  static void config(const char* const, const char* const, uint8, uint8);
// given device name, return its address.
  static bool lookup(const char* const name, ID_T& address);
// Given address, return device name.
  static bool lookup(ID_T address, char* const name);
  static uint8 system(void) { return _systemid; }
  static uint8 subsystem(void) { return _subsystemid; }
protected:
  void load_table(void);
  static char _devices[];
  static char _sysname[8];
  static char _subsysname[8];
  static uint8 _systemid;
  static uint8 _subsystemid;
};

#endif

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