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#include "FiveWin.ch"

FIELD First, Last

function Main()

   USE Customer VIA "DBFNTX"

   INDEX ON First+Last TO Customer
   SET INDEX TO
   
   SubNtx( "customer.ntx", { | nRecNo, cKey | Test( nRecNo, cKey ) } )

return nil

function Test( nRecNo, cKey ) // In this test we show the first 10 keys only

   static nTimes := 1
   
   if nTimes < 11 
      MsgInfo( cKey, "Key: " + AllTrim( Str( nTimes++ ) ) + ;
               " --> RecNo: " + AllTrim( Str( nRecNo ) ) )
   endif
   
return nil      

#pragma BEGINDUMP

#include <hbapi.h>
#include <hbapifs.h>
#include <hbvm.h>

#define MAX_KEY  256
#define BUF_SIZE 1024

typedef struct 
{
	unsigned short int     type;
	unsigned short int     version;
	long     root;
	long     next_page;
	unsigned short int     item_size;
	unsigned short int     key_size;
	unsigned short int     key_dec;
	unsigned short int     max_item;
	unsigned short int     half_page;
	char     key_expr[ MAX_KEY ];
	char     unique;
} NTX_HEADER;

typedef struct
{
	long page;
	long rec_no;
	char key[ 1 ];
} NTX_ITEM;

typedef struct
{
	unsigned short item_count;
	unsigned short item_offset[ 1 ];
} NTX_BUFFER;

static void ReadPage( int hFileIn, long page_offset, PHB_ITEM pCodeBlock, unsigned short int iKeySize )
{
   char ntxPage[ BUF_SIZE ];
	 NTX_ITEM * pNtxItem;
	 NTX_BUFFER * pNtxBuffer;
   int i;
   
   hb_fsSeek( hFileIn, page_offset, FS_SET );
   
	 if( hb_fsRead( hFileIn, ntxPage, BUF_SIZE ) != BUF_SIZE ) 
	    return;
	    
	 pNtxBuffer = ( NTX_BUFFER * ) ntxPage;   
	    
	 for( i = 0; i < pNtxBuffer->item_count; i ++ ) 
	 {
	    pNtxItem = ( NTX_ITEM * ) ( ntxPage + pNtxBuffer->item_offset[ i ] );

 	    if( pNtxItem->page )
		     ReadPage( hFileIn, pNtxItem->page, pCodeBlock, iKeySize );
		     
		  hb_vmPushSymbol( &hb_symEval );
		  hb_vmPush( pCodeBlock );
		  hb_vmPushLong( pNtxItem->rec_no );
		  hb_vmPushString( ( char * ) &pNtxItem->key, iKeySize );
		  hb_vmFunction( 2 );
   }   

	 pNtxItem = ( NTX_ITEM * ) ( ntxPage + pNtxBuffer->item_offset[ pNtxBuffer->item_count ] );
	 
	 if( pNtxItem->page )
	    ReadPage( hFileIn, pNtxItem->page, pCodeBlock, iKeySize );
}

HB_FUNC( SUBNTX )
{
   NTX_HEADER ntx_header;   
   int hFileIn = hb_fsOpen( hb_parc( 1 ), FO_READ );
   PHB_ITEM pCodeBlock = hb_param( 2, HB_IT_BLOCK );

   if( hFileIn != -1 )
   {
      hb_fsRead( hFileIn, ( char * ) &ntx_header, sizeof( NTX_HEADER ) );
      
      ReadPage( hFileIn, ntx_header.root, pCodeBlock, ntx_header.key_size );

      hb_fsClose( hFileIn );    
   }  
}

#pragma ENDDUMP