Example: data collection program

C++ sample code

#include "string.h"                     // memcpy(), memset(), strlen()
#include "stdio.h"                     // printf()
#include "qpmdcprm.h"                   // data collection program interface
#include "time.h"

extern "C"
void DCPentry( Qpm_DC_Parm_t *request, char *dataBuffer,
                                                         char *workArea, int *returnCode )
{
  static  char  testData[21] = "Just some test stuff";
  int           i;



/* Print contents of request structure */

  printf( "DCP called with parameters:\n" );
  printf( "  format name: \"%8.8s\";  category name: \"%10.10s\";\n",
          request->formatName, request->categoryName );
  printf( "  rsvd1: %4.4X; req type: %d; req mod: %d; buffer len: %d;\n",
          *(short *)(request->rsvd1), request->requestType,
          request->requestModifier, request->dataBufferLength);
  printf( "  prm offset: %d; prm len: %d; work len: %d; rsvd2: %8.8X;\n",
          request->parmOffset, request->parmLength, request->workAreaLength,
          *(int *)(request->rsvd2) );
  printf( "  rec key: \"%8.8s\"; timestamp: %8.8X %8.8X;\n",
          request->intervalKey,
          *(int *)(request->intervalTimestamp),
          *(int *)(request->intervalTimestamp + 4) );
  printf( "  return len: %d; more data: %d; rsvd3: %8.8X %8.8X;\n",
          request->bytesProvided, request->moreData,
          *(int *)(request->rsvd3),
          *(int *)(request->rsvd3 + 4) );

  switch ( request->requestType )
  { 
  /* Write control record in the beginning of collection */
    case PM_DOBEGIN:
      printf( "doBegin(%d)\n", request->requestModifier );
      switch ( request->requestModifier)
      {
        case PM_CALL_NORMAL:
            memcpy( dataBuffer, testData, 20 );
            *(int *)workArea = 20;
            request->moreData = PM_MORE_DATA;
            request->bytesProvided = 20;
          break;

        case PM_CALL_CONTINUE:
          if ( *(int *)workArea < 200 )
          {
            memcpy( dataBuffer, testData, 20 );
            *(int *)workArea += 20;
            request->moreData = PM_MORE_DATA;
            request->bytesProvided = 20;
          }
          else
          {
            *(int *)workArea = 0;
            request->moreData = PM_NO_MORE_DATA;
            request->bytesProvided = 0;
          }
          break;

        default:
          *returnCode = -1;
          return;
      }
      break;
 /* Write control record in the end of collection */
    case PM_DOEND:
      printf( "doEnd(%d)\n", request->requestModifier );
      switch ( request->requestModifier)
      {
        case PM_CALL_NORMAL:
            memcpy( dataBuffer, testData, 20 );
            *(int *)workArea = 20;
            request->moreData = PM_MORE_DATA;
            request->bytesProvided = 20;
          break;

        case PM_CALL_CONTINUE:
          if ( *(int *)workArea < 200 )
          {
            memcpy( dataBuffer, testData, 20 );
            *(int *)workArea += 20;
            request->moreData = PM_MORE_DATA;
            request->bytesProvided = 20;
          }
          else
          {
            *(int *)workArea = 0;
            request->moreData = PM_NO_MORE_DATA;
            request->bytesProvided = 0;
          }
          break;

        default:
          *returnCode = -1;
          return;
      }
      break;
          
 /*Write interval record */
    case PM_DOCOLLECT:
      printf( "doCollect(%d)\n", request->requestModifier );
      for ( i = 0; i < 10000; i++ )
        dataBuffer[i] = i % 256;
      request->bytesProvided = 10000;

      switch ( request->requestModifier)
      {
        case PM_CALL_NORMAL:
            *(time_t *)(workArea + 4) = time( NULL );
            *(int *)workArea = 1;
            request->moreData = PM_MORE_DATA;
          break;

        case PM_CALL_CONTINUE:
          *(int *)workArea += 1;
          if ( *(int *)workArea < 20 )
            request->moreData = PM_MORE_DATA;
          else
          {
            *(time_t *)(workArea + 8) = time( NULL );
            printf( "doCollect() complete in %d secs (%d bytes transferred)\n",
                    *(time_t *)(workArea + 8) - *(time_t *)(workArea + 4), 10000 * 20 );
            request->moreData = PM_NO_MORE_DATA;
          }
          break;

        default:
          *returnCode = -1;
          return;
      }
      break;
 /* Clean-up and terminate */
    case PM_DOSHUTDOWN:
      printf( "doShutdown\n" );
      *returnCode = 0;
      return;
      break;

    default:
      *returnCode = -1;
      return;
      break;
  }

}/* DCPentry() */