lr.c

extremeDB s sample code,useful for you

	    
	};
	
	if ( rc != 0 ) {
	
	  Printf( "Error: %d\n", rc);
		
	};
};

MUTEX_T Lock;
unsigned char mode = 0;

THREAD_PROC_DEFINE( work_with_database, p) {

	unsigned int 	passes = 1, i;
	MCO_RET			rc = MCO_S_OK;
	mco_trans_h 	t;
	mco_cursor_t	c;
	Obj				obj;

	for (; rc == MCO_S_OK ;) {
	  /* check stop-condition */
	  MUTEX_LOCK( &Lock );
	  if ( mode != 0 ) {
	    break;
	  }
	  MUTEX_UNLOCK( &Lock );

	  /* delete first 10 objects every 10 passes */
    if ( passes % 10 == 0 ) {

	    /* delete first 10 items */
	    for ( i=0; i<10; i++) {
	    
	      /* open a transaction */
	      if ( MCO_S_OK != (rc = mco_trans_start( db, MCO_READ_WRITE, MCO_TRANS_FOREGROUND, &t ) )) {
		      /* error */
		      Printf( "Unable to start a transaction\n");
		      break;
		      
	      } else { /* OK */
		            
		      /* get index cursor */
		      Obj_index_index_cursor( t, &c );
		      
		      /* get the first object */
		      mco_cursor_first( t, &c );
		      Obj_from_cursor ( t, &c, &obj );

		      /* delete the object */
		      if ( MCO_S_OK == (rc = Obj_delete( &obj ))) {

			      /* commit transaction */
			      rc = mco_trans_commit( t );
	      
		      } else {

			      /* rollback transaction */
			      mco_trans_rollback( t );
			      break;
		      };
	      };
	    };
    }

	  /* making the snapshot every 15 passes */
	  if(slave_flag) {
	    if((int)p == 0) {
  	    if ( passes % 15 == 0 ) {
	        if ( MCO_S_OK != (rc=mco_log_save( db, deferred_deletion_mode ))) {
			      Printf ("\nUnable to make snapshot of the database. Error %d\n", rc );
      		}
	      }
	    }  
	  }

	  /* make an object */
	  /* open a transaction */
	  if ( MCO_S_OK != (rc = mco_trans_start( db, MCO_READ_WRITE, MCO_TRANS_FOREGROUND, &t ) )) {
		  /* error */
		  Printf( "Unable to start a transaction\n");
	  } else { /* OK */
	  
	    /* get index cursor */
	    Obj_index_index_cursor( t, &c );
	    
	    /* get the last object */
	    mco_cursor_last( t, &c );
	    Obj_from_cursor ( t, &c, &obj );
	    
	    /* get the last index value */
	    Obj_index_get( &obj, &i );
	    i++;

	    /* make an object */
	    if ( MCO_S_OK == (rc = make_an_object( t, i ))) {
	    
		    /* commit transaction */
		    rc = mco_trans_commit( t );
		    
	    } else {
	    
		    /* rollback transaction */
		    mco_trans_rollback( t );
	    };
	  };
	    
	  /* show the database state */
	  show_db_info ();
	  
	  /* wait and go to the next cycle */
	  Sleep( 100 );
	  passes ++;
	};	
	
	mode--;
	MUTEX_UNLOCK( &Lock );
};

/* deferred deletion thread */
THREAD_PROC_DEFINE( deferred_deletion, p ) {
  THREAD_PROC_MODE()
	mco_log_deferred_deletion( db );
}

mco_bool FlushTimer (struct flush_timer_* handle)
{
    if(handle->flush_time) {
      if ( handle->time_elapsed == 0 )  
        handle->time_elapsed = mco_system_get_current_time();

      if( (mco_system_get_current_time()-handle->time_elapsed) 
          > handle->flush_time) {
        handle->time_elapsed = 0;
        return TRUE;
      }
    }
    return FALSE;
}

/* parse command line */

int parse_cmd_line(int argc, char* argv[])
{
  int i, flag = 0;

    for(i=1; i < argc; i++) {
	  if (strstr(argv[i],"--test")) test_Mode = 1;
	  else
		  if(argv[i][0] == '-') {
			if( (argv[i][1] == 'd') || (argv[i][1] == 'D') ) {
			  flag ++;
			  deferred_deletion_mode = 0; /* clear "deferred deletion" flag if "-d" specified */
			}
			if((argv[i][1] == 's') || (argv[i][1] == 'S')) {
			  flag ++;
			  slave_flag = 0;              /* set "slave mode" flag if "-s" specified */
			}
			if((argv[i][1] == 'm') || (argv[i][1] == 'M')) {
			  flag ++;
			  slave_flag = 1;              /* set "master mode" flag if "-m" specified */
			}
			if((argv[i][1] == 'w') || (argv[i][1] == 'W')) {
			  flag ++;
			  if( !(thread_num = atoi( &argv[i][2])) ) /* set the desired number of working threads */
				thread_num = 1;
			  if( thread_num > 9) thread_num = 9;
			}
			if((argv[i][1] == 'f') || (argv[i][1] == 'F')) {
			  flag ++;
			  if( !(flush_depth = atoi( &argv[i][2])) ) /* set the desired counter of transactions */
				flush_depth = 1;
			}
			if((argv[i][1] == 't') || (argv[i][1] == 'T')) {
			  flag ++;
			  if( !(flush_time = atoi( &argv[i][2])) ) /* set the desired flush time */
				flush_time = 100;
			}
			if((argv[i][1] == 'h') || (argv[i][1] == 'H')) {
			  help();
			  EXIT(0);
			}
			if((argv[i][1] == 'n') || (argv[i][1] == 'N')) {
			  flag ++;
			  mode_flags |= MCO_LOG_NONBUFFERED_IO;     /* nonbuffered mode */
			}
		  }
    }

    return flag;
}

int main ( int argc, char* argv[]) {

	MCO_RET 	rc,rc1;
	THREAD_ID_T tw;

  int i;
  flush_timer_t   flush_timer;

  rc=rc1=0;
    _SH_();
    
    /* common initialization */
    srand( time(0) );
    MUTEX_INIT( &Lock );

    /* parse the command line */

    if( !parse_cmd_line( argc, argv ) ) {
#ifndef _WIN32_WCE
      usage();
#else
      char str[128];

      usage();
      Printf("\nPress ENTER to exit\n");
      gets(str);
#endif
      PROG_EXIT(0);
    }
	
    /* initialize the database */
    init_database();

    /* initialize transaction logging */

    {
      log_args_t  args;
      args.Filepath   = LOG_FILEPATH;
      args.maxlogsize = LOG_MAX_FILESIZE;
      args.maxfiles   = LOG_MAX_FILES_IN_DIR;
      args.flags      = mode_flags; //  MCO_LOG_CLOSE | MCO_LOG_NONBUFFERED_IO flags
      args.flush_depth  = flush_depth;
      args.flush_timer  = &flush_timer;
      flush_timer.flush_time  = flush_time; // flush time in milliseconds
      flush_timer.TimerProc = FlushTimer;

      rc = mco_log_start(db,  &args );
    }

    if ( MCO_S_OK != rc)
    {
      Printf( "Unable to initialize transaction log. Error: %d\n", rc);
    }
    else {
      if(slave_flag) {
	      /* Try to restore the database from logged data */
	      Printf ("Try to restore database: ");
	      if ( MCO_S_OK != (rc = rc1 = mco_log_recover( db )) ) {
	        Printf( " Failed. Error %d",rc);
	        switch ( rc ) {
	          case MCO_E_LOG_IMG_NOT_FOUND:
				  {rc=0;Printf( " \"Logs were not found\"." ); break;}
		          
	          case MCO_E_LOG_BROKEN_RECORD:
		          Printf( " \"Broken record\"." ); if (test_Mode) goto Exit; break;
	          default:
		          Printf( " \"Database image or logs are broken\"." );
              goto Exit;
			        
    	    };
    	    Printf( "\n" );

          /* Make initial snapshot of the database */
	        Printf ("Making database's snapshot: ");
	        if ( MCO_S_OK != (rc=mco_log_save( db, 1 ))) {
  		       Printf ( "Failed. Error %d\n", rc );
             goto Exit;
	        } else {
	          Printf ( "OK\n");
	        };

          if ( rc1 == MCO_E_LOG_IMG_NOT_FOUND) {
	          /* fill the database */
	          Printf ( "Old database doesn't exist.\n");
		        if (MCO_S_OK != (rc=populate_database()))
					goto Exit;
          }

	      }
        else {
	          Printf( " Done\nThe database's state is:\n" );
	          show_db_info ();
	          Printf( "\n" );
	      };


      }
      else {
      	Printf ( "Slave mode, database is assumed to be recovered\n");
      }
	
      /* start "deferred deletion" if the flag specified */
      if ( deferred_deletion_mode == 0 ) {
	      Printf( "\"Deferred deletion\" is enabled. Starting thread:" );
	      THREAD_PROC_START( deferred_deletion, 0, &td );
	      Printf( "Done\n" );
      };

      Printf( "Press any key to normal exit or Ctrl+C to terminate the program\n");

      /* show current state of the database */
      show_db_info ();
	
		/* starts "working hard" */
      for(i=0;i<(int)thread_num;i++) {
  	 THREAD_PROC_START( work_with_database, (void*)i, &tw );
      }

      /* waits for user's choose */
	  if (test_Mode) Sleep(15000);
      getchar();

      /* stop the thread */
      MUTEX_LOCK( &Lock );
      mode = (int)thread_num;
      MUTEX_UNLOCK( &Lock );
      for (;;) {
	      MUTEX_LOCK( &Lock );
	      if ( mode ==0 ) break;
	      MUTEX_UNLOCK( &Lock );
	      Sleep( 100 );
      
      };
      MUTEX_UNLOCK( &Lock );

Exit:      
      mco_log_stop( db );
    };
		
    /* cleanup */
    if(td != (THREAD_ID_T)INVALID_HANDLE_VALUE)
      THREAD_CANCEL(td);
    
    free_database();
    
    Sleep(200);

    MUTEX_DESTROY( &Lock );
    
    PROG_EXIT(rc);
};