nonin/src/NoninStreamParser.c

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/*
-----------------------------------------------------------------------------
This source file is part of OpenSpace3D
For the latest info, see http://www.openspace3d.com

Copyright (c) 2010 I-maginer

This program 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 of the License, or (at your option) any later
version.

This program 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 program; if not, write to the Free Software Foundation, Inc., 59 Temple
Place - Suite 330, Boston, MA 02111-1307, USA, or go to
http://www.gnu.org/copyleft/lesser.txt

You may alternatively use this source under the terms of a specific version of
the OpenSpace3D Unrestricted License provided you have obtained such a license from
I-maginer.
-----------------------------------------------------------------------------
*/

#include "NoninStreamParser.h"

/* Include libraries required specifically by this implementation of this
 * library and not already included by this library's header
 */
#include <stdio.h>

/* Decoder states (Packet decoding) */
#define PARSER_STATE_NULL           0x00  /* NULL state */
#define PARSER_STATE_SYNC           0x01  /* Waiting for SYNC byte */
#define PARSER_STATE_SYNC_CHECK     0x02  /* SYNC byte Checked */
#define PARSER_STATE_PLETHMSB       0x03  /* Waiting for PLETH MSB */
#define PARSER_STATE_PLETHLSB       0x04  /* Waiting for PLETH LSB */
#define PARSER_STATE_DATA           0x05  /* Waiting for DATA byte */
#define PARSER_STATE_CHKSUM         0x06  /* Waiting for CHK byte */

/*
 * See header file for interface documentation.
 */
int
NONIN_initParser( NoninStreamParser *parser,
                      void (*handleDataValueFunc)(unsigned char frame, unsigned char plethMSB, unsigned char plethLSB, unsigned char data, void *customData),
                      void *customData ) {

    if( !parser ) return( -1 );

    /* Initialize the parser's state based on the parser type */
    parser->state = PARSER_STATE_SYNC;
    /* Save parser type */
    /* Save user-defined handler function and data pointer */
    parser->handleDataValue = handleDataValueFunc;
    parser->customData = customData;
    parser->frame = PARSER_CODE_HRMSB;

    return( 0 );
}

/*
 * See header file for interface documentation.
 */
int
NONIN_parseByte( NoninStreamParser *parser, unsigned char byte ) 
{
    int returnValue = 0;
    if( !parser ) return( -1 );

    /* Pick handling according to current state... */
    switch( parser->state ) {

        /* Waiting for SyncByte */
        case( PARSER_STATE_SYNC ):
            if( byte == 1 ) {
                parser->check = 0;
                parser->state = PARSER_STATE_SYNC_CHECK;
                parser->sync = 1;
                returnValue = 1;
            }
            else
              returnValue = -1;
            break;

        /* Waiting for PLETH MSB length */
        case( PARSER_STATE_SYNC_CHECK ):
            parser->state = PARSER_STATE_PLETHMSB;
            // Treat Pleth MSB Byte
            parser->plethMSBByte = byte;
            returnValue = 2;
            break;

          /* Waiting for PLETH LSB length */
          case( PARSER_STATE_PLETHMSB ):
            parser->state = PARSER_STATE_PLETHLSB;
            // Treat Pleth MSB Byte
            parser->plethLSBByte = byte;
            returnValue = 3;
            break;
            

          /* Waiting for PLETH LSB length */
          case( PARSER_STATE_PLETHLSB ):
            parser->state = PARSER_STATE_DATA;
            // Treat DATA Byte
            parser->dataByte = byte;
            returnValue = 4;
            break;

          /* Waiting for CKSUM byte */
          case( PARSER_STATE_DATA ):
              parser->chksum = byte;
              parser->state = PARSER_STATE_CHKSUM;
              // If checksum (frame is valid)
              /*if(parser->sync + parser->plethMSBByte + parser->plethLSBByte + parser->dataByte == parser->chksum)
              {*/
                parser->check = 1;
                parser->handleDataValue(parser->frame,parser->plethMSBByte,parser->plethLSBByte, parser->dataByte, parser->customData);
                parser->state = PARSER_STATE_SYNC;
                returnValue = 5;
              //}
              break;


            /* unrecognized state */
            default:
              returnValue = -6;
              break;
    }
    return( returnValue );
}


int parseFrame( NoninStreamParser *parser ) 
{
  // Parse validate Frame
  // ChecSum
  if( parser->handleDataValue ) 
  {
    parser->handleDataValue(parser->frame,parser->plethMSBByte,parser->plethLSBByte, parser->dataByte, parser->customData);
    return 0;
  }
  return -1;
}

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