/*
 * $Id$
 */

/*
 * Harbour Project source code:
 * DBFNTX RDD
 *
 * Copyright 1999 Bruno Cantero <bruno@issnet.net>
 * www - http://www.harbour-project.org
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this software; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
 * Boston, MA 02111-1307 USA (or visit the web site http://www.gnu.org/).
 *
 * As a special exception, the Harbour Project gives permission for
 * additional uses of the text contained in its release of Harbour.
 *
 * The exception is that, if you link the Harbour libraries with other
 * files to produce an executable, this does not by itself cause the
 * resulting executable to be covered by the GNU General Public License.
 * Your use of that executable is in no way restricted on account of
 * linking the Harbour library code into it.
 *
 * This exception does not however invalidate any other reasons why
 * the executable file might be covered by the GNU General Public License.
 *
 * This exception applies only to the code released by the Harbour
 * Project under the name Harbour.  If you copy code from other
 * Harbour Project or Free Software Foundation releases into a copy of
 * Harbour, as the General Public License permits, the exception does
 * not apply to the code that you add in this way.  To avoid misleading
 * anyone as to the status of such modified files, you must delete
 * this exception notice from them.
 *
 * If you write modifications of your own for Harbour, it is your choice
 * whether to permit this exception to apply to your modifications.
 * If you do not wish that, delete this exception notice.
 *
 */
/*
 * The following functions are added by
 *       Alexander Kresin <alex@belacy.belgorod.su>
 *
 * commonError()
 * hb_IncString()
 * ntxNumToStr()
 * checkLogicalExpr()
 * hb__ntxTagKeyCount()
 * hb_ntxInTopScope()
 * hb_ntxInBottomScope()
 * hb_ntxTagKeyNo()
 * hb_ntxTagKeyCount()
 * hb_ntxClearScope()
 * hb_ntxGoEof()
 * hb_ntxGetKeyType()
 * hb_ntxTagKeyFind()
 * hb_ntxPageKeySearch()
 * hb_ntxTagFindCurrentKey()
 * hb_ntxIsRecBad()
 * hb_ntxPageFindCurrentKey()
 * hb_ntxGetCurrentKey()
 * hb_ntxTagGoToNextKey()
 * hb_ntxTagGoToPrevKey()
 * hb_ntxTagGoToTopKey()
 * hb_ntxTagGoToBottomKey()
 * hb_ntxTagKeyGoTo()
 * hb_ntxPageRelease()
 * hb_ntxKeysMove()
 * hb_ntxPageSplit()
 * hb_ntxPageJoin()
 * hb_ntxPageBalance()
 * hb_ntxTagBalance()
 * hb_ntxPageKeyDel()
 * hb_ntxTagKeyAdd()
 * hb_ntxSwapPageSave()
 * hb_ntxKeysSort()
 * hb_ntxSortKeyAdd()
 * hb_ntxSortKeyEnd()
 * hb_ntxWritePage()
 * hb_ntxRootPage()
 * hb_ntxGetSortedKey()
 * hb_ntxBufferSave()
 * hb_ntxReadBuf()
 * hb_ntxPageFind()
 * ntxFindIndex()
 * hb_ntxOrdKeyAdd()
 * hb_ntxOrdKeyDel()
 * ntxGoBottom()
 * ntxGoTo()
 * ntxGoTop()
 * ntxSeek()
 * ntxSkipRaw()
 * ntxGoCold()
 * ntxGoHot()
 * ntxSysName()
 * ntxPack()
 * ntxZap()
 * ntxClearScope()
 * ntxScopeInfo()
 * ntxOrderListAdd()
 * ntxOrderListClear()
 * ntxOrderListFocus()
 * ntxOrderListRebuild()
 * ntxSetScope()
 */

/*
 * Copyright 2005 Przemyslaw Czerpak <druzus@priv.onet.pl>
 * in practice most of the code rewritten
 */

/* #define HB_NTX_NOMULTITAG */

/* #define HB_NTX_EXTERNAL_PAGEBUFFER */

#define HB_NTX_STRONG_BALANCE

/*
#define HB_NTX_DEBUG
#define HB_NTX_DEBUG_EXT
#define HB_NTX_DEBUG_DISP
*/

#include "hbapi.h"
#include "hbapiitm.h"
#include "hbinit.h"
#include "hbapierr.h"
#include "hbapilng.h"
#include "hbvm.h"
#include "hbset.h"
#include "hbmath.h"
#include "hbrddntx.h"
#include "rddsys.ch"
#ifdef __XHARBOUR__
#include "hbregex.h"
#endif
#ifndef HB_CDP_SUPPORT_OFF
   #include "hbapicdp.h"
#endif

#ifdef HB_NTX_DEBUG_DISP
   static ULONG s_rdNO = 0;
   static ULONG s_wrNO = 0;
#endif
static RDDFUNCS ntxSuper;
static USHORT s_uiRddId;

static BOOL s_fSortRecNo = FALSE;
static BOOL s_fMultiKey = FALSE;
static BOOL s_fStruct = FALSE;
static BOOL s_fStrictStruct = FALSE;
#if !defined( HB_NTX_NOMULTITAG )
static BOOL s_fMultiTag = TRUE;
#endif

#define hb_ntxKeyFree(K)      hb_xfree(K)
#define hb_ntxFileOffset(I,B) ( (B) << ( (I)->LargeFile ? NTXBLOCKBITS : 0 ) )
#define hb_ntxPageBuffer(p)   ( (p)->buffer )

/*
 * The helper functions (endian dependent) - on big endian machines
 * or RISC with strict alignment it's much better to use functions
 * then macros to inform compiler that can count complex parameters
 * only once.
 * On other machines it should not cause noticeable differences because
 * most of modern C compilers auto inline small functions
 */
#if defined( HB_LITTLE_ENDIAN ) && !defined( HB_STRICT_ALIGNMENT )

#define hb_ntxGetKeyCount(p)        HB_GET_LE_UINT16( hb_ntxPageBuffer(p) )
#define hb_ntxSetKeyCount(p,n)      HB_PUT_LE_UINT16( hb_ntxPageBuffer(p), (n) )

#define hb_ntxGetKeyOffset(p,n)     HB_GET_LE_UINT16( hb_ntxPageBuffer(p)+2+((n)<<1) )
#define hb_ntxGetKeyPtr(p,n)        ( hb_ntxPageBuffer(p) + hb_ntxGetKeyOffset(p,n) )
#define hb_ntxGetKeyPage(p,n)       HB_GET_LE_UINT32( hb_ntxGetKeyPtr(p,n) )
#define hb_ntxGetKeyRec(p,n)        HB_GET_LE_UINT32( hb_ntxGetKeyPtr(p,n)+4 )
#define hb_ntxGetKeyVal(p,n)        ( hb_ntxGetKeyPtr(p,n)+8 )

#define hb_ntxSetKeyOffset(p,n,u)   HB_PUT_LE_UINT16( hb_ntxPageBuffer(p)+2+((n)<<1), u )
#define hb_ntxSetKeyPage(p,n,l)     HB_PUT_LE_UINT32( hb_ntxGetKeyPtr(p,n), l )
#define hb_ntxSetKeyRec(p,n,l)      HB_PUT_LE_UINT32( hb_ntxGetKeyPtr(p,n)+4, l )

#else

static USHORT hb_ntxGetKeyCount( LPPAGEINFO pPage )
{
   char * ptr = hb_ntxPageBuffer( pPage );
   return HB_GET_LE_UINT16( ptr );
}

static void hb_ntxSetKeyCount( LPPAGEINFO pPage, USHORT uiKeys )
{
   char * ptr = hb_ntxPageBuffer( pPage );
   HB_PUT_LE_UINT16( ptr, uiKeys );
}

static USHORT hb_ntxGetKeyOffset( LPPAGEINFO pPage, SHORT iKey )
{
   char * ptr = hb_ntxPageBuffer( pPage ) + 2 + ( iKey << 1 );
   return HB_GET_LE_UINT16( ptr );
}

static void hb_ntxSetKeyOffset( LPPAGEINFO pPage, SHORT iKey, USHORT uiOffset )
{
   char * ptr = hb_ntxPageBuffer( pPage ) + 2 + ( iKey << 1 );
   HB_PUT_LE_UINT16( ptr, uiOffset );
}

static char * hb_ntxGetKeyPtr( LPPAGEINFO pPage, SHORT iKey )
{
   return hb_ntxPageBuffer( pPage ) + hb_ntxGetKeyOffset( pPage, iKey );
}

static ULONG hb_ntxGetKeyPage( LPPAGEINFO pPage, SHORT iKey )
{
   char * ptr = hb_ntxGetKeyPtr( pPage, iKey );
   return HB_GET_LE_UINT32( ptr );
}

static void hb_ntxSetKeyPage( LPPAGEINFO pPage, SHORT iKey, ULONG ulPage )
{
   char * ptr = hb_ntxGetKeyPtr( pPage, iKey );
   HB_PUT_LE_UINT32( ptr, ulPage );
}

static char * hb_ntxGetKeyVal( LPPAGEINFO pPage, SHORT iKey )
{
   return hb_ntxGetKeyPtr( pPage, iKey ) + 8;
}

static void hb_ntxSetKeyRec( LPPAGEINFO pPage, SHORT iKey, ULONG ulRec )
{
   char * ptr = hb_ntxGetKeyPtr( pPage, iKey ) + 4;
   HB_PUT_LE_UINT32( ptr, ulRec );
}

static ULONG hb_ntxGetKeyRec( LPPAGEINFO pPage, SHORT iKey )
{
   char * ptr = hb_ntxGetKeyPtr( pPage, iKey ) + 4;
   return HB_GET_LE_UINT32( ptr );
}

#endif

/*
 * generate Run-Time error
 */
static ERRCODE hb_ntxErrorRT( NTXAREAP pArea, USHORT uiGenCode, USHORT uiSubCode, char * szFileName, USHORT uiOsCode, USHORT uiFlags )
{
   PHB_ITEM pError;
   ERRCODE iRet = FAILURE;

   if( hb_vmRequestQuery() == 0 )
   {
      pError = hb_errNew();
      hb_errPutGenCode( pError, uiGenCode );
      hb_errPutSubCode( pError, uiSubCode );
      hb_errPutOsCode( pError, uiOsCode );
      hb_errPutDescription( pError, hb_langDGetErrorDesc( uiGenCode ) );
      if( szFileName )
         hb_errPutFileName( pError, szFileName );
      if( uiFlags )
         hb_errPutFlags( pError, uiFlags );
      iRet = SELF_ERROR( ( AREAP ) pArea, pError );
      hb_errRelease( pError );
   }
   return iRet;
}

/*
 * convert numeric item into NTX key value
 */
static char * hb_ntxNumToStr( PHB_ITEM pItem, char* szBuffer, USHORT length, USHORT dec )
{
   char *ptr = szBuffer;

   hb_itemStrBuf( szBuffer, pItem, length, dec );

   while( *ptr == ' ' )
      *ptr++ = '0';

   if( *ptr == '-' )
   {
      *ptr = '0';
      for( ptr = &szBuffer[0]; *ptr; ptr++ )
      {
         if( *ptr >= '0' && *ptr <= '9' )
            *ptr = (char) ( '0' - ( *ptr - '0' ) - 4 );
            /*
             * I intentionally used the above formula to avoid problems on
             * non ASCII machines though many of other xHarbour codes is
             * hard coded to ASCII values and should be fixed. Druzus.
             */
      }
   }

   return szBuffer;
}

/*
 * convert numeric NTX key value into item
 */
static PHB_ITEM hb_ntxStrToNum( PHB_ITEM pItem, char* szKeyVal, USHORT length, USHORT dec )
{
   char szBuffer[ NTX_MAX_KEY + 1 ];
   char *ptr = szKeyVal, *ptr2, c;
   int iLen, iDec;
   HB_LONG lValue;
   double dValue;

   HB_SYMBOL_UNUSED( dec );

   if( *ptr == '0' - 4 ) /* negative number */
   {
      ptr2 = szBuffer;
      while( ( c = *ptr++ ) != 0 )
      {
         if( c != '.' )
            c = '0' - ( c - '0' + 4 );
         *ptr2++ = c;
      }
      szBuffer[ 0 ] = '-';
      *ptr2 = '\0';
      ptr = szBuffer;
   }
   if( hb_valStrnToNum( ptr, length, &lValue, &dValue, &iDec, &iLen ) )
      return hb_itemPutNDLen( pItem, dValue, iLen, iDec );
   else
      return hb_itemPutNIntLen( pItem, lValue, length );
}

/*
 * create new index key
 */
static LPKEYINFO hb_ntxKeyNew( LPKEYINFO pKeyFrom, int keylen )
{
   LPKEYINFO pKey;

   pKey = ( LPKEYINFO ) hb_xgrab( sizeof( KEYINFO ) + keylen );
   if( pKeyFrom )
   {
      memcpy( pKey->key, pKeyFrom->key, keylen + 1 );
      pKey->Tag = pKeyFrom->Tag;
      pKey->Xtra = pKeyFrom->Xtra;
   }
   else
   {
      pKey->key[ keylen ] = '\0';
      pKey->Tag = pKey->Xtra = 0;
   }
   return pKey;
}

/*
 * copy index key, if dst is null create new dst key else destroy dst
 */
static LPKEYINFO hb_ntxKeyCopy( LPKEYINFO pKeyDest, LPKEYINFO pKey, int keylen )
{
   if( !pKeyDest )
      pKeyDest = hb_ntxKeyNew( NULL, keylen );

   memcpy( pKeyDest->key, pKey->key, keylen + 1 );
   pKeyDest->Tag = pKey->Tag;
   pKeyDest->Xtra = pKey->Xtra;

   return pKeyDest;
}

/*
 * get ntx key type for given item
 */
static BYTE hb_ntxItemType( PHB_ITEM pItem )
{
   switch( hb_itemType( pItem ) )
   {
      case HB_IT_STRING:
      case HB_IT_STRING | HB_IT_MEMO:
         return 'C';

      case HB_IT_INTEGER:
      case HB_IT_LONG:
      case HB_IT_DOUBLE:
         return 'N';

      case HB_IT_DATE:
         return 'D';

      case HB_IT_LOGICAL:
         return 'L';

      default:
         return 'U';
   }
}

/*
 * store Item in index key
 * TODO: uiType check and generate RT error if necessary
 *       probably not here or we will have to add parameter
 *       for scope key evaluation
 */
static LPKEYINFO hb_ntxKeyPutItem( LPKEYINFO pKey, PHB_ITEM pItem, ULONG ulRecNo,
                                   LPTAGINFO pTag, BOOL fTrans, USHORT *puiLen )
{
   ULONG len;

   if( !pKey )
      pKey = hb_ntxKeyNew( NULL, pTag->KeyLength );

   if( puiLen )
      *puiLen = pTag->KeyLength;

   switch( hb_ntxItemType( pItem ) )
   {
      case 'C':
         len = hb_itemGetCLen( pItem );
         if( len < ( ULONG ) pTag->KeyLength )
         {
            memcpy( pKey->key, hb_itemGetCPtr( pItem ), len );
            memset( pKey->key + len, ' ', pTag->KeyLength - len );
            if( puiLen )
               *puiLen = ( USHORT ) len;
         }
         else
         {
            memcpy( pKey->key, hb_itemGetCPtr( pItem ), pTag->KeyLength );
         }
         pKey->key[ pTag->KeyLength ] = '\0';
#ifndef HB_CDP_SUPPORT_OFF
         if( fTrans )
            hb_cdpnTranslate( pKey->key, hb_cdp_page, pTag->Owner->Owner->cdPage, pTag->KeyLength );
#else
         HB_SYMBOL_UNUSED( fTrans );
#endif
         break;
      case 'N':
         hb_ntxNumToStr( pItem, pKey->key, pTag->KeyLength, pTag->KeyDec );
         break;
      case 'D':
         hb_itemGetDS( pItem, pKey->key );
         break;
      case 'L':
         pKey->key[0] = ( hb_itemGetL( pItem ) ? 'T':'F' );
         pKey->key[1] = 0;
         break;
      default:
         memset( pKey->key, '\0', pTag->KeyLength );
   }
   pKey->Xtra = ulRecNo;
   pKey->Tag = 0;

   return pKey;
}

/*
 * get Item from index key
 */
static PHB_ITEM hb_ntxKeyGetItem( PHB_ITEM pItem, LPKEYINFO pKey,
                                  LPTAGINFO pTag, BOOL fTrans )
{
   if( pKey )
   {
      switch( pTag->KeyType )
      {
         case 'C':
#ifndef HB_CDP_SUPPORT_OFF
            if( fTrans && pTag->Owner->Owner->cdPage != hb_cdp_page )
            {
               char * pVal = ( char * ) hb_xgrab( pTag->KeyLength + 1 );
               memcpy( pVal, pKey->key, pTag->KeyLength );
               pVal[ pTag->KeyLength ] = '\0';
               hb_cdpnTranslate( pVal, pTag->Owner->Owner->cdPage, hb_cdp_page,
                                 pTag->KeyLength );
               pItem = hb_itemPutCPtr( pItem, pVal, pTag->KeyLength );
            }
            else
#else
            HB_SYMBOL_UNUSED( fTrans );
#endif
            {
               pItem = hb_itemPutCL( pItem, pKey->key, pTag->KeyLength );
            }
            break;
         case 'N':
            pItem = hb_ntxStrToNum( pItem, pKey->key, pTag->KeyLength, pTag->KeyDec );
            break;
         case 'D':
            pItem = hb_itemPutDS( pItem, pKey->key );
            break;
         case 'L':
            pItem = hb_itemPutL( pItem, pKey->key[0] == 'T' );
            break;
         default:
            if( pItem )
               hb_itemClear( pItem );
            else
               pItem = hb_itemNew( NULL );
      }
   }
   else if( pItem )
      hb_itemClear( pItem );
   else
      pItem = hb_itemNew( NULL );

   return pItem;
}

/*
 * evaluate conditional expression and return the logical result
 */
static BOOL hb_ntxEvalCond( NTXAREAP pArea, PHB_ITEM pCondItem, BOOL fSetWA )
{
   int iCurrArea = 0;
   BOOL fRet;

   if( fSetWA )
   {
      iCurrArea = hb_rddGetCurrentWorkAreaNumber();
      if( iCurrArea != pArea->uiArea )
         hb_rddSelectWorkAreaNumber( pArea->uiArea );
      else
         iCurrArea = 0;
   }

   fRet = hb_itemGetL( hb_vmEvalBlockOrMacro( pCondItem ) );

   if( iCurrArea )
      hb_rddSelectWorkAreaNumber( iCurrArea );

   return fRet;
}

/*
 * evaluate seek/skip block: {|key, rec| ... }
 */
static BOOL hb_ntxEvalSeekCond( LPTAGINFO pTag, PHB_ITEM pCondItem )
{
   BOOL fRet;
   PHB_ITEM pKeyVal, pKeyRec;

   pKeyVal = hb_ntxKeyGetItem( NULL, pTag->CurKeyInfo, pTag, TRUE );
   pKeyRec = hb_itemPutNInt( NULL, pTag->CurKeyInfo->Xtra );

   fRet = hb_itemGetL( hb_vmEvalBlockV( pCondItem, 2, pKeyVal, pKeyRec ) );

   hb_itemRelease( pKeyVal );
   hb_itemRelease( pKeyRec );

   return fRet;
}

/*
 * get ITEM type of key expression
 */
static BYTE hb_ntxGetKeyType( LPTAGINFO pTag )
{
   BYTE bType;

   if( pTag->nField )
   {
      PHB_ITEM pItem = hb_itemNew( NULL );
      SELF_GETVALUE( ( AREAP ) pTag->Owner->Owner, pTag->nField, pItem );
      bType = hb_ntxItemType( pItem );
      hb_itemRelease( pItem );
   }
   else
   {
      int iCurrArea = hb_rddGetCurrentWorkAreaNumber();

      if( iCurrArea != pTag->Owner->Owner->uiArea )
         hb_rddSelectWorkAreaNumber( pTag->Owner->Owner->uiArea );
      else
         iCurrArea = 0;

      bType = hb_ntxItemType( hb_vmEvalBlockOrMacro( pTag->pKeyItem ) );

      if( iCurrArea )
         hb_rddSelectWorkAreaNumber( iCurrArea );
   }
   return bType;
}

/*
 * evaluate key expression and create new Key from the result
 */
static LPKEYINFO hb_ntxEvalKey( LPKEYINFO pKey, LPTAGINFO pTag )
{
   NTXAREAP pArea = pTag->Owner->Owner;
   PHB_ITEM pItem;
#ifndef HB_CDP_SUPPORT_OFF
   /* TODO%: this hack is not thread safe, hb_cdp_page has to be thread specific */
   PHB_CODEPAGE cdpTmp = hb_cdp_page;
   hb_cdp_page = pArea->cdPage;
#endif

   if( pTag->nField )
   {
      pItem = hb_itemNew( NULL );
      SELF_GETVALUE( ( AREAP ) pArea, pTag->nField, pItem );
      pKey = hb_ntxKeyPutItem( pKey, pItem, pArea->ulRecNo, pTag, FALSE, NULL );
      hb_itemRelease( pItem );
   }
   else
   {
      int iCurrArea = hb_rddGetCurrentWorkAreaNumber();

      if( iCurrArea != pArea->uiArea )
         hb_rddSelectWorkAreaNumber( pArea->uiArea );
      else
         iCurrArea = 0;

      pItem = hb_vmEvalBlockOrMacro( pTag->pKeyItem );
      pKey = hb_ntxKeyPutItem( pKey, pItem, pArea->ulRecNo, pTag, FALSE, NULL );

      if( iCurrArea )
         hb_rddSelectWorkAreaNumber( iCurrArea );
   }

#ifndef HB_CDP_SUPPORT_OFF
   hb_cdp_page = cdpTmp;
#endif

   return pKey;
}

/*
 * compare two values using Tag conditions (len & type)
 */
static int hb_ntxValCompare( LPTAGINFO pTag, char* val1, int len1,
                             char* val2, int len2, BOOL fExact )
{
   int iLimit, iResult = 0;

   iLimit = (len1 > len2) ? len2 : len1;

   if( pTag->KeyType == 'C' )
   {
      if( iLimit > 0 )
      {
#ifndef HB_CDP_SUPPORT_OFF
         if( pTag->Owner->Owner->cdPage->lSort )
            iResult = hb_cdpcmp( val1, val2, ( ULONG ) iLimit, pTag->Owner->Owner->cdPage, NULL );
         else
#endif
            iResult = memcmp( val1, val2, iLimit );
      }

      if( iResult == 0 )
      {
         if( len1 > len2 )
            iResult = 1;
         else if( len1 < len2 && fExact )
            iResult = -1;
      }
   }
   else
   {
      if( iLimit <= 0 || (iResult = memcmp( val1, val2, iLimit )) == 0 )
      {
         if( len1 > len2 )
            iResult = 1;
         else if( len1 < len2 )
            iResult = -1;
      }
   }
   return iResult;
}

/*
 * check if a given key is in top scope
 */
static BOOL hb_ntxInTopScope( LPTAGINFO pTag, char* key )
{
   PHB_NTXSCOPE pScope = pTag->fUsrDescend ? &pTag->bottom : &pTag->top;

   if( pScope->scopeKeyLen )
   {
      int i = hb_ntxValCompare( pTag, pScope->scopeKey->key, pScope->scopeKeyLen,
                                 key, pTag->KeyLength, FALSE );
      return pTag->fUsrDescend ? i >= 0 : i <= 0;
   }
   else
      return TRUE;
}

/*
 * check if a given key is in bottom scope
 */
static BOOL hb_ntxInBottomScope( LPTAGINFO pTag, char* key )
{
   PHB_NTXSCOPE pScope = pTag->fUsrDescend ? &pTag->top : &pTag->bottom;

   if( pScope->scopeKeyLen )
   {
      int i = hb_ntxValCompare( pTag, pScope->scopeKey->key, pScope->scopeKeyLen,
                                key, pTag->KeyLength, FALSE );
      return pTag->fUsrDescend ? i <= 0 : i >= 0;
   }
   else
      return TRUE;
}

/*
 * check if a given key is in current scope
 */
static BOOL hb_ntxKeyInScope( LPTAGINFO pTag, LPKEYINFO pKey )
{
   return hb_ntxInTopScope( pTag, pKey->key ) &&
          hb_ntxInBottomScope( pTag, pKey->key );
}

/*
 * clear top or bottom scope
 */
static void hb_ntxTagClearScope( LPTAGINFO pTag, USHORT nScope )
{
   NTXAREAP pArea = pTag->Owner->Owner;
   PHB_NTXSCOPE pScope;

   /* resolve any pending scope relations first */
   if( pArea->lpdbPendingRel && pArea->lpdbPendingRel->isScoped )
      SELF_FORCEREL( ( AREAP ) pArea );

   if( pTag->fUsrDescend )
      nScope = ( nScope == 0 ) ? 1 : 0;

   pScope = ( nScope == 0 ) ? &pTag->top : &pTag->bottom;

   if( pScope->scopeKey )
   {
      hb_ntxKeyFree( pScope->scopeKey );
      pScope->scopeKey = NULL;
   }
   if( pScope->scopeItem )
   {
      hb_itemRelease( pScope->scopeItem );
      pScope->scopeItem = NULL;
   }
   pScope->scopeKeyLen = 0;

   pTag->keyCount = 0;
}

/*
 * set top or bottom scope
 */
static void hb_ntxTagSetScope( LPTAGINFO pTag, USHORT nScope, PHB_ITEM pItem )
{
   NTXAREAP pArea = pTag->Owner->Owner;
   PHB_ITEM pScopeVal;

   /* resolve any pending scope relations first */
   if( pArea->lpdbPendingRel && pArea->lpdbPendingRel->isScoped )
      SELF_FORCEREL( ( AREAP ) pArea );

   pScopeVal = ( hb_itemType( pItem ) == HB_IT_BLOCK ) ?
                           hb_vmEvalBlock( pItem ) : pItem;

   if( pTag->KeyType == hb_ntxItemType( pScopeVal ) )
   {
      PHB_NTXSCOPE pScope;
      BOOL fTop = ( nScope == 0 );

      if( pTag->fUsrDescend )
         fTop = !fTop;

      pScope = fTop ? &pTag->top : &pTag->bottom;

      pScope->scopeKey = hb_ntxKeyPutItem( pScope->scopeKey, pScopeVal,
               ( fTop == pTag->AscendKey ) ? NTX_IGNORE_REC_NUM : NTX_MAX_REC_NUM,
               pTag, TRUE, &pScope->scopeKeyLen );

      if( pScope->scopeItem == NULL )
         pScope->scopeItem = hb_itemNew( NULL );
      hb_itemCopy( pScope->scopeItem, pItem );

      pTag->keyCount = 0;
   }
   else
   {
      hb_ntxTagClearScope( pTag, nScope );
   }
}

/*
 * get top or bottom scope item
 */
static void hb_ntxTagGetScope( LPTAGINFO pTag, USHORT nScope, PHB_ITEM pItem )
{
   NTXAREAP pArea = pTag->Owner->Owner;
   PHB_NTXSCOPE pScope;

   /* resolve any pending scope relations first */
   if( pArea->lpdbPendingRel && pArea->lpdbPendingRel->isScoped )
      SELF_FORCEREL( ( AREAP ) pArea );

   if( pTag->fUsrDescend )
      nScope = ( nScope == 0 ) ? 1 : 0;

   pScope = ( nScope == 0 ) ? &pTag->top : &pTag->bottom;

   if( pScope->scopeItem )
      hb_itemCopy( pItem, pScope->scopeItem );
   else
      hb_itemClear( pItem );
}

/*
 * refresh top and bottom scope value if set as codeblock
 */
static void hb_ntxTagRefreshScope( LPTAGINFO pTag )
{
   PHB_ITEM pItem;

   /* resolve any pending scope relations first */
   if( pTag->Owner->Owner->lpdbPendingRel &&
       pTag->Owner->Owner->lpdbPendingRel->isScoped )
      SELF_FORCEREL( ( AREAP ) pTag->Owner->Owner );

   if( hb_itemType( pTag->top.scopeItem ) == HB_IT_BLOCK )
   {
      pItem = hb_vmEvalBlock( pTag->top.scopeItem );
      pTag->top.scopeKey = hb_ntxKeyPutItem( pTag->top.scopeKey, pItem,
               pTag->top.scopeKey->Xtra, pTag, TRUE, &pTag->top.scopeKeyLen );
   }
   if( hb_itemType( pTag->bottom.scopeItem ) == HB_IT_BLOCK )
   {
      pItem = hb_vmEvalBlock( pTag->bottom.scopeItem );
      pTag->bottom.scopeKey = hb_ntxKeyPutItem( pTag->bottom.scopeKey, pItem,
         pTag->bottom.scopeKey->Xtra, pTag, TRUE, &pTag->bottom.scopeKeyLen );
   }
}

/*
 * an interface for fast check record number in record filter
 */
static BOOL hb_ntxCheckRecordScope( NTXAREAP pArea, ULONG ulRec )
{
   LONG lRecNo = ( LONG ) ulRec;

   if ( SELF_COUNTSCOPE( ( AREAP ) pArea, NULL, &lRecNo ) == SUCCESS && lRecNo == 0 )
   {
      return FALSE;
   }
   return TRUE;
}

#ifdef HB_NTX_DEBUG
static void hb_ntxTagCheckBuffers( LPTAGINFO pTag )
{
   LPPAGEINFO pPage;
   ULONG i;

   if( ( pTag->HdrChanged || pTag->Owner->Changed ) && !pTag->Owner->lockWrite )
      hb_errInternal( 9999, "hb_ntxTagCheckBuffers: tag modified in unlocked index", "", "" );

   for( i = 0; i < pTag->Owner->ulPages; i++ )
   {
      pPage = pTag->Owner->pages[ i ];
      if( pPage->Changed && !pTag->Owner->lockWrite )
         hb_errInternal( 9999, "hb_ntxTagCheckBuffers: page modified in unlocked index", "", "" );
      if( pPage->iUsed )
         hb_errInternal( 9999, "hb_ntxTagCheckBuffers: page still allocated", "", "" );
   }
}

static void hb_ntxPageCheckKeys( LPPAGEINFO pPage, LPTAGINFO pTag, int iPos, int iType )
{
   USHORT u;
   int i;

   for( u = 1; u < pPage->uiKeys; u++ )
   {
      i = hb_ntxValCompare( pTag,
                            hb_ntxGetKeyVal( pPage, u - 1 ), pTag->KeyLength,
                            hb_ntxGetKeyVal( pPage, u ), pTag->KeyLength, TRUE );
      if( !pTag->AscendKey )
         i = -i;
      if( i > 0 )
      {
         printf("\r\nuiKeys=%d(%d/%d), (%d)[%.*s]>(%d)[%.*s]", pPage->uiKeys, iPos, iType,
                u - 1, pTag->KeyLength, hb_ntxGetKeyVal( pPage, u - 1 ),
                u, pTag->KeyLength, hb_ntxGetKeyVal( pPage, u ) );
         fflush(stdout);
         hb_errInternal( 9999, "hb_ntxPageCheckKeys: keys sorted wrong.", "", "" );
      }
   }
}
#endif

/*
 * read a given block from index file
 */
static BOOL hb_ntxBlockRead( LPNTXINDEX pIndex, ULONG ulBlock, BYTE *buffer, int iSize )
{
   if( !pIndex->lockRead && !pIndex->lockWrite )
      hb_errInternal( 9103, "hb_ntxBlockRead on not locked index file.", "", "" );

#ifdef HB_NTX_DEBUG_DISP
   s_rdNO++;
#endif
   hb_fsSeekLarge( pIndex->DiskFile,
                   hb_ntxFileOffset( pIndex, ulBlock ), FS_SET );
   if( hb_fsRead( pIndex->DiskFile, buffer, iSize ) != iSize )
   {
      hb_ntxErrorRT( pIndex->Owner, EG_READ, EDBF_READ,
                     pIndex->IndexName, hb_fsError(), 0 );
      return FALSE;
   }
   return TRUE;
}

/*
 * write a given block into index file
 */
static BOOL hb_ntxBlockWrite( LPNTXINDEX pIndex, ULONG ulBlock, BYTE *buffer, int iSize )
{
   if( !pIndex->lockWrite )
      hb_errInternal( 9102, "hb_ntxBlockWrite on not locked index file.", "", "" );

#ifdef HB_NTX_DEBUG_DISP
   s_wrNO++;
#endif
   hb_fsSeekLarge( pIndex->DiskFile,
                   hb_ntxFileOffset( pIndex, ulBlock ), FS_SET );
   if( hb_fsWrite( pIndex->DiskFile, buffer, iSize ) != iSize )
   {
      hb_ntxErrorRT( pIndex->Owner, EG_WRITE, EDBF_WRITE,
                     pIndex->IndexName, hb_fsError(), 0 );
      return FALSE;
   }
   return TRUE;
}

/*
 * write a given tag page to file
 */
static BOOL hb_ntxPageSave( LPNTXINDEX pIndex, LPPAGEINFO pPage )
{
   hb_ntxSetKeyCount( pPage, pPage->uiKeys );
   if( !hb_ntxBlockWrite( pIndex, pPage->Page,
                          (BYTE *) hb_ntxPageBuffer( pPage ), NTXBLOCKSIZE ) )
      return FALSE;
   pPage->Changed = FALSE;
   pIndex->fFlush = TRUE;
   /* In shared mode we have to update counter in version field of
      NTXHEADER to signal for other stations that their index buffers
      has to be discarded */
   if( pIndex->fShared )
      pIndex->Changed = TRUE;
   return TRUE;
}

/*
 * discard all index buffers due to concurrent access
 */
static void hb_ntxDiscardBuffers( LPNTXINDEX pIndex )
{
   pIndex->ulPages = pIndex->ulPageLast = 0;
   pIndex->pChanged = pIndex->pFirst = pIndex->pLast = NULL;
   if( pIndex->Compound )
   {
      int i;

      for( i = 0; i < pIndex->iTags; i++ )
      {
         pIndex->lpTags[ i ]->RootBlock = 0;
         pIndex->lpTags[ i ]->stackLevel = 0;
      }
   }
   else
   {
      pIndex->TagBlock = 0;
      if( pIndex->iTags )
         pIndex->lpTags[ 0 ]->stackLevel = 0;
   }
}

/*
 * update tag flags
 */
static void hb_ntxTagUpdateFlags( LPTAGINFO pTag )
{
   USHORT uiSignature = pTag->Signature;

   pTag->Custom    = ( uiSignature & NTX_FLAG_CUSTOM ) != 0;
   pTag->ChgOnly   = ( uiSignature & NTX_FLAG_CHGONLY ) != 0;
   pTag->Partial   = ( uiSignature & NTX_FLAG_PARTIAL ) != 0;
   pTag->Template  = ( uiSignature & NTX_FLAG_TEMPLATE ) != 0;
   pTag->MultiKey  = ( uiSignature & NTX_FLAG_MULTIKEY ) != 0;
   pTag->fSortRec  = ( uiSignature & NTX_FLAG_SORTRECNO ) != 0;
}

/*
 * check tag header in compound index
 */
static BOOL hb_ntxTagHeaderCheck( LPTAGINFO pTag )
{
   if( !pTag->RootBlock )
   {
      if( pTag->HeadBlock )
      {
         BYTE buffer[ 12 ];
         if( hb_ntxBlockRead( pTag->Owner, pTag->HeadBlock, buffer, 12 ) )
         {
            pTag->Signature = HB_GET_LE_UINT16( ( ( LPNTXHEADER ) buffer )->type );
            pTag->RootBlock = HB_GET_LE_UINT32( ( ( LPNTXHEADER ) buffer )->root );
            hb_ntxTagUpdateFlags( pTag );
         }
      }
   }
   return pTag->RootBlock != 0;
}

/*
 * free buffers for pages in the tag
 */
static void hb_ntxFreePageBuffer( LPNTXINDEX pIndex )
{
   ULONG ul, ulMax = pIndex->ulPagesDepth;
   LPPAGEINFO * pPagePtr = pIndex->pages;

   if( ulMax )
   {
      for( ul = 0; ul < ulMax; ul++, pPagePtr++ )
      {
         if( *pPagePtr )
         {
#ifdef HB_NTX_EXTERNAL_PAGEBUFFER
            if( hb_ntxPageBuffer( *pPagePtr ) )
               hb_xfree( hb_ntxPageBuffer( *pPagePtr ) );
#endif
            hb_xfree( *pPagePtr );
         }
      }
      hb_xfree( pIndex->pages );
      pIndex->pages = NULL;
      pIndex->ulPages = pIndex->ulPageLast = pIndex->ulPagesDepth = 0;
      pIndex->pFirst = pIndex->pLast = pIndex->pChanged = NULL;
   }
}

/*
 * trunc index file, left only space for header
 */
static void hb_ntxIndexTrunc( LPNTXINDEX pIndex )
{
   if( !pIndex->lockWrite )
      hb_errInternal( 9102, "hb_ntxIndexTrunc on not locked index file.", "", "" );

   hb_ntxFreePageBuffer( pIndex );
   pIndex->Update = pIndex->Changed = pIndex->fFlush = TRUE;
   pIndex->TagBlock = pIndex->NextAvail = 0;
   pIndex->Version = 0;
   hb_fsSeek( pIndex->DiskFile, NTXBLOCKSIZE, FS_SET );
   hb_fsWrite( pIndex->DiskFile, NULL, 0 );
}

/*
 * try to find given tag page in the buffer
 */
static LPPAGEINFO hb_ntxPageFind( LPTAGINFO pTag, ULONG ulPage )
{
   LPPAGEINFO * pPagePtr = pTag->Owner->pages;
   ULONG u;

   for( u = pTag->Owner->ulPages; u; u--, pPagePtr++ )
   {
      if( *pPagePtr && (*pPagePtr)->Page == ulPage )
         return *pPagePtr;
   }
   return NULL;
}

/*
 * try to find free space in buffer
 */
static LPPAGEINFO hb_ntxPageGetBuffer( LPTAGINFO pTag, ULONG ulPage )
{
   LPNTXINDEX pIndex = pTag->Owner;
   LPPAGEINFO * pPagePtr;

   if( pIndex->ulPages < pIndex->ulPagesDepth )
   {
      pPagePtr = &pIndex->pages[ pIndex->ulPages++ ];
   }
   else if( pIndex->pFirst )
   {
      LPPAGEINFO pPage = pIndex->pFirst;

      if( pPage->iUsed )
         hb_errInternal( 9999, "hb_ntxPageGetBuffer: page used.", "", "" );
      if( pPage->Changed )
         hb_errInternal( 9999, "hb_ntxPageGetBuffer: page changed.", "", "" );

      pIndex->pFirst = pPage->pNext;
      if( pIndex->pFirst )
         pIndex->pFirst->pPrev = NULL;
      else
         pIndex->pLast = NULL;
      pPage->pPrev = NULL;
      pPage->Page = ulPage;
      pPage->iUsed = 1;

      return pPage;
   }
   else if( pIndex->ulPagesDepth == 0 )
   {
      pIndex->ulPages = 1;
      pIndex->ulPageLast = 0;
      pIndex->ulPagesDepth = NTX_PAGES_PER_TAG;
      pIndex->pages = (LPPAGEINFO*) hb_xgrab( sizeof(LPPAGEINFO) * NTX_PAGES_PER_TAG );
      memset( pIndex->pages, 0, sizeof(LPPAGEINFO) * NTX_PAGES_PER_TAG );
      pPagePtr = &pIndex->pages[0];
   }
   else
   {
      ULONG ul = pIndex->ulPageLast;
      do
      {
         if( ++ul >= pIndex->ulPagesDepth )
            ul = 0;
         pPagePtr = &pIndex->pages[ ul ];
         if( !(*pPagePtr)->iUsed && !(*pPagePtr)->Changed )
         {
            pIndex->ulPageLast = ul;
            break;
         }
         if( ul == pIndex->ulPageLast )
         {
            ul = pIndex->ulPagesDepth;
            pIndex->ulPagesDepth += NTX_PAGES_PER_TAG >> 1;
            pIndex->pages = (LPPAGEINFO*) hb_xrealloc( pIndex->pages,
                                 sizeof(LPPAGEINFO) * pIndex->ulPagesDepth );
            memset( pIndex->pages + ul, 0,
                         ( NTX_PAGES_PER_TAG >> 1 ) * sizeof( LPPAGEINFO ) );
            pIndex->ulPages++;
            pPagePtr = &pIndex->pages[ ul ];
            pIndex->ulPageLast = 0;
            break;
         }
      }
      while( TRUE );
   }

   if( !*pPagePtr )
   {
      *pPagePtr = ( LPPAGEINFO ) hb_xgrab( sizeof( HB_PAGEINFO ) );
      memset( *pPagePtr, 0, sizeof( HB_PAGEINFO ) );
   }
#ifdef HB_NTX_EXTERNAL_PAGEBUFFER
   if( !hb_ntxPageBuffer( *pPagePtr ) )
   {
      hb_ntxPageBuffer( *pPagePtr ) = ( char* ) hb_xgrab( NTXBLOCKSIZE );
      memset( hb_ntxPageBuffer( *pPagePtr ), 0, NTXBLOCKSIZE );
   }
#endif
   (*pPagePtr)->pPrev = NULL;
   (*pPagePtr)->Page = ulPage;
   (*pPagePtr)->iUsed = 1;
   return *pPagePtr;
}

/*
 * free the index page for future reuse
 */
static void hb_ntxPageFree( LPTAGINFO pTag, LPPAGEINFO pPage )
{
   hb_ntxSetKeyPage( pPage, 0, pTag->Owner->NextAvail );
   pTag->Owner->NextAvail = pPage->Page;
   pTag->Owner->Changed = pPage->Changed = TRUE;
}

/*
 * mark used page as free
 */
static void hb_ntxPageRelease( LPTAGINFO pTag, LPPAGEINFO pPage )
{
   LPNTXINDEX pIndex = pTag->Owner;

   if( --pPage->iUsed == 0 )
   {
      if( pPage->Changed )
      {
         if( !pPage->pPrev )
         {
            pPage->pPrev = pPage;
            pPage->pNext = pIndex->pChanged;
            pIndex->pChanged = pPage;
         }
      }
      else if( pIndex->pLast )
      {
         pIndex->pLast->pNext = pPage;
         pPage->pPrev = pIndex->pLast;
         pPage->pNext = NULL;
         pIndex->pLast = pPage;
      }
      else
      {
         pPage->pNext = pPage->pPrev = NULL;
         pIndex->pFirst = pIndex->pLast = pPage;
      }
   }
   else if( pPage->iUsed < 0 )
      hb_errInternal( 9999, "hb_ntxPageRelease: unused page freed.", "", "" );
}

/*
 * load page from index file or the buffer
 */
static LPPAGEINFO hb_ntxPageLoad( LPTAGINFO pTag, ULONG ulPage )
{
   LPPAGEINFO pPage;

   if( !ulPage )
   {
      if( hb_ntxTagHeaderCheck( pTag ) )
         ulPage = pTag->RootBlock;
      if( !ulPage )
      {
         hb_ntxErrorRT( pTag->Owner->Owner, EG_CORRUPTION, EDBF_CORRUPT,
                        pTag->Owner->IndexName, 0, 0 );
      }
   }
   pPage = hb_ntxPageFind( pTag, ulPage );
   if( pPage )
   {
      if( !pPage->Changed && !pPage->iUsed )
      {
         if( pPage->pNext )
            pPage->pNext->pPrev = pPage->pPrev;
         else
            pTag->Owner->pLast = pPage->pPrev;
         if( pPage->pPrev )
         {
            pPage->pPrev->pNext = pPage->pNext;
            pPage->pPrev = NULL;
         }
         else
            pTag->Owner->pFirst = pPage->pNext;
      }
      pPage->iUsed++;
   }
   else
   {
      pPage = hb_ntxPageGetBuffer( pTag, ulPage );
      if( !hb_ntxBlockRead( pTag->Owner, ulPage,
                            (BYTE *) hb_ntxPageBuffer( pPage ), NTXBLOCKSIZE ) )
         return NULL;
      pPage->Changed = FALSE;
      pPage->uiKeys = hb_ntxGetKeyCount( pPage );
   }
   return pPage;
}

/*
 * initialize empty page structure
 */
static void hb_ntxPageInit( LPTAGINFO pTag, LPPAGEINFO pPage )
{
   USHORT u, o = ( pTag->MaxKeys + 2 ) << 1;

   for( u = 0; u <= pTag->MaxKeys; u++, o += pTag->KeyLength + 8 )
      hb_ntxSetKeyOffset( pPage, u, o );
   hb_ntxSetKeyPage( pPage, 0, 0 );
   pPage->uiKeys = 0;
}

/*
 * allocate new page address
 */
static ULONG hb_ntxPageAlloc( LPNTXINDEX pIndex )
{
   ULONG ulPage;
   if( !pIndex->TagBlock )
   {
      HB_FOFFSET fOffset;
      fOffset = hb_fsSeekLarge( pIndex->DiskFile, 0, FS_END );
      pIndex->TagBlock = ( ULONG )
                     ( fOffset >> ( pIndex->LargeFile ? NTXBLOCKBITS : 0 ) );
   }
   ulPage = pIndex->TagBlock;
   pIndex->TagBlock += pIndex->LargeFile ? 1 : NTXBLOCKSIZE;
   return ulPage;
}

/*
 * allocate new page in index file - reuse freed one or increase file
 */
static LPPAGEINFO hb_ntxPageNew( LPTAGINFO pTag, BOOL fNull )
{
   LPPAGEINFO pPage;

   if( pTag->Owner->NextAvail != 0 )
   {
      /* Handling of a pool of empty pages.
         Some sources says that this address is in the first 4 bytes of
         a page ( http://www.e-bachmann.dk/docs/xbase.htm ).
         But as I understood, studying dumps of Clipper ntx'es, address of the
         next available page is in the address field of a first key item
         in the page - it is done here now in such a way.
         = Alexander Kresin =
      */
      pPage = hb_ntxPageLoad( pTag, pTag->Owner->NextAvail );
      if( ! pPage )
         return NULL;
      if( pPage->uiKeys != 0 )
      {
         hb_ntxErrorRT( pTag->Owner->Owner, EG_CORRUPTION, EDBF_CORRUPT,
                        pTag->Owner->IndexName, 0, 0 );
         return NULL;
      }
      pTag->Owner->NextAvail = hb_ntxGetKeyPage( pPage, 0 );
#if defined( HB_NTX_NOMULTITAG )
      hb_ntxSetKeyPage( pPage, 0, 0 );
      pPage->uiKeys = 0;
#else
      hb_ntxPageInit( pTag, pPage );
#endif
   }
   else
   {
      pPage = hb_ntxPageGetBuffer( pTag, fNull ? 0 : hb_ntxPageAlloc( pTag->Owner ) );
      hb_ntxPageInit( pTag, pPage );
   }
   pTag->Owner->Changed = pPage->Changed = TRUE;

   return pPage;
}

/*
 * add given page to list of free pages
 */
static void hb_ntxPageAddFree( LPTAGINFO pTag, ULONG ulPage )
{
   LPPAGEINFO pPage = hb_ntxPageGetBuffer( pTag, ulPage );
   pPage->Changed = TRUE;
   hb_ntxPageInit( pTag, pPage );
   hb_ntxPageFree( pTag, pPage );
   hb_ntxPageSave( pTag->Owner, pPage );
   hb_ntxPageRelease( pTag, pPage );
}

/*
 * get free page in index file
 */
static ULONG hb_ntxPageGetFree( LPTAGINFO pTag )
{
   LPPAGEINFO pPage = hb_ntxPageNew( pTag, FALSE );
   ULONG ulPage = 0;

   if( pPage )
   {
      ulPage = pPage->Page;
      pPage->Changed = FALSE;
      hb_ntxPageRelease( pTag, pPage );
   }
   return ulPage;
}

/*
 * create the new tag structure
 */
static LPTAGINFO hb_ntxTagNew( LPNTXINDEX pIndex,
                               char * szTagName, BOOL fTagName,
                               char *szKeyExpr, PHB_ITEM pKeyExpr,
                               BYTE bKeyType, USHORT uiKeyLen, USHORT uiKeyDec,
                               char *szForExpr, PHB_ITEM pForExpr,
                               BOOL fAscendKey, BOOL fUnique, BOOL fCustom,
                               BOOL fSortRec )
{
   LPTAGINFO pTag;

   pTag = ( LPTAGINFO ) hb_xgrab( sizeof( TAGINFO ) );
   memset( pTag, 0, sizeof( TAGINFO ) );
   pTag->TagName = hb_strndup( szTagName, NTX_MAX_TAGNAME );
   pTag->fTagName = fTagName;
   pTag->Owner = pIndex;
   if( szKeyExpr )
   {
      pTag->KeyExpr = hb_strndup( szKeyExpr, NTX_MAX_EXP );
   }
   if( pForExpr && szForExpr )
   {
      pTag->ForExpr = hb_strndup( szForExpr, NTX_MAX_EXP );
   }
   pTag->nField = hb_rddFieldExpIndex( ( AREAP ) pIndex->Owner, pTag->KeyExpr );
   pTag->pKeyItem = pKeyExpr;
   pTag->pForItem = pForExpr;
   pTag->AscendKey = fAscendKey;
   pTag->fUsrDescend = !pTag->AscendKey;
   pTag->UniqueKey = fUnique;
   pTag->Custom = fCustom;
   pTag->MultiKey = fCustom && s_fMultiKey;
   pTag->KeyType = bKeyType;
   pTag->KeyLength = uiKeyLen;
   pTag->KeyDec = uiKeyDec;
   pTag->fSortRec = fSortRec;
   /*
    * TODO?: keep during page update the offset to 'MaxKeys' key fixed
    * so we will be able to store 1 key more in the page
    */
   pTag->MaxKeys = ( NTXBLOCKSIZE - 2 ) / ( uiKeyLen + 10 ) - 1;

   /* TODO?: is it necessary? It should not interact with well implemented
      algorithm */
   if( pTag->MaxKeys & 0x01 && pTag->MaxKeys > 2 )
      pTag->MaxKeys--;

   pTag->CurKeyInfo = hb_ntxKeyNew( NULL, pTag->KeyLength );

   return pTag;
}

/*
 * free from memory tag structure
 */
static void hb_ntxTagFree( LPTAGINFO pTag )
{
   if( pTag == pTag->Owner->Owner->lpCurTag )
      pTag->Owner->Owner->lpCurTag = NULL;
   hb_xfree( pTag->TagName );
   if( pTag->KeyExpr )
      hb_xfree( pTag->KeyExpr );
   if( pTag->ForExpr )
      hb_xfree( pTag->ForExpr );
   if( pTag->pKeyItem )
      hb_vmDestroyBlockOrMacro( pTag->pKeyItem );
   if( pTag->pForItem )
      hb_vmDestroyBlockOrMacro( pTag->pForItem );
   if( pTag->HotKeyInfo )
      hb_ntxKeyFree( pTag->HotKeyInfo );
   hb_ntxKeyFree( pTag->CurKeyInfo );
   hb_ntxTagClearScope( pTag, 0 );
   hb_ntxTagClearScope( pTag, 1 );
   if( pTag->stack )
      hb_xfree( pTag->stack );
   hb_xfree( pTag );
}

/*
 * delete tag from compund index
 */
static void hb_ntxTagDelete( LPTAGINFO pTag )
{
   LPNTXINDEX pIndex = pTag->Owner;
   int i;

   for( i = 0; i < pIndex->iTags; i++ )
   {
      if( pTag == pIndex->lpTags[ i ] )
      {
         while( ++i < pIndex->iTags )
            pIndex->lpTags[ i - 1 ] = pIndex->lpTags[ i ];
         if( --pIndex->iTags )
            pIndex->lpTags = ( LPTAGINFO * ) hb_xrealloc( pIndex->lpTags,
                                       sizeof( LPTAGINFO ) * pIndex->iTags );
         else
            hb_xfree( pIndex->lpTags );
         break;
      }
   }
   hb_ntxTagFree( pTag );
   pIndex->Owner->fSetTagNumbers = TRUE;
   return;
}

/*
 * add tag to compund index
 */
static ERRCODE hb_ntxTagAdd( LPNTXINDEX pIndex, LPTAGINFO pTag )
{
   if( pIndex->iTags >= CTX_MAX_TAGS )
      return FAILURE;

   if( pIndex->iTags )
      pIndex->lpTags = ( LPTAGINFO * ) hb_xrealloc( pIndex->lpTags,
                                 sizeof( LPTAGINFO ) * ( pIndex->iTags + 1 ) );
   else
      pIndex->lpTags = ( LPTAGINFO * ) hb_xgrab( sizeof( LPTAGINFO ) );

   pIndex->lpTags[ pIndex->iTags++ ] = pTag;
   pIndex->Owner->fSetTagNumbers = TRUE;
   return SUCCESS;
}

/*
 * create new tag and load it from index file
 */
static LPTAGINFO hb_ntxTagLoad( LPNTXINDEX pIndex, ULONG ulBlock,
                                char * szTagName, BYTE * buffer )
{
   LPNTXHEADER lpNTX = ( LPNTXHEADER ) buffer;
   LPTAGINFO pTag;
   PHB_ITEM pKeyExp, pForExp = NULL;
   USHORT usType;
   BOOL fName;

   usType = HB_GET_LE_UINT16( lpNTX->type );

   if( ( usType & ~NTX_FLAG_MASK ) ||
       ( ( usType & NTX_FLAG_DEFALUT ) != NTX_FLAG_DEFALUT &&
         usType != NTX_FLAG_OLDDEFALUT ) ||
       lpNTX->key_expr[0] < 0x20 )
      return NULL;

   if( SELF_COMPILE( ( AREAP ) pIndex->Owner, lpNTX->key_expr ) == FAILURE )
      return NULL;
   pKeyExp = pIndex->Owner->valResult;
   pIndex->Owner->valResult = NULL;

   if( usType & NTX_FLAG_FORITEM && lpNTX->for_expr[0] >= 0x20 )
   {
      if( SELF_COMPILE( ( AREAP ) pIndex->Owner, lpNTX->for_expr ) == FAILURE )
      {
         hb_vmDestroyBlockOrMacro( pKeyExp );
         return NULL;
      }
      pForExp = pIndex->Owner->valResult;
      pIndex->Owner->valResult = NULL;
   }
   fName = !pIndex->Compound && lpNTX->tag_name[0] >= 0x20;
   pTag = hb_ntxTagNew( pIndex,
                        fName ? (char *) lpNTX->tag_name : szTagName, fName,
                        (char *) lpNTX->key_expr, pKeyExp,
                        '\0',
                        HB_GET_LE_UINT16( lpNTX->key_size ),
                        HB_GET_LE_UINT16( lpNTX->key_dec ),
                        (char *) lpNTX->for_expr, pForExp,
                        lpNTX->descend[0] == 0, lpNTX->unique[0] != 0,
                        ( usType & NTX_FLAG_CUSTOM ) != 0 || lpNTX->custom[0] != 0,
                        ( usType & NTX_FLAG_SORTRECNO ) != 0 );

   pTag->Signature = usType;
   hb_ntxTagUpdateFlags( pTag );
   pTag->HeadBlock = ulBlock;
   pTag->RootBlock = HB_GET_LE_UINT32( lpNTX->root );
   pTag->MaxKeys = HB_GET_LE_UINT16( lpNTX->max_item );
   pTag->KeyType = hb_ntxGetKeyType( pTag );

   pIndex->LargeFile = ( usType & NTX_FLAG_LARGEFILE ) != 0;

   if( !pIndex->Compound )
   {
      pIndex->Version = HB_GET_LE_UINT16( lpNTX->version );
      pIndex->NextAvail = HB_GET_LE_UINT32( lpNTX->next_page );
      pIndex->TagBlock = 0;

      /* TODO: this breaks unlocking !!! */
      if( usType & NTX_FLAG_LARGEFILE )
      {
         pIndex->Owner->bLockType = DB_DBFLOCK_XHB64;
      }
      else if( usType & NTX_FLAG_EXTLOCK )
      {
         pIndex->Owner->bLockType = DB_DBFLOCK_CL53EXT;
      }
      else if( ! pIndex->Owner->bLockType )
      {
         pIndex->Owner->bLockType = usType & NTX_FLAG_EXTLOCK ?
                           DB_DBFLOCK_CL53EXT : DB_DBFLOCK_CLIP;
      }
   }
   return pTag;
}

/*
 * add tag into CTX header
 */
static void hb_ntxIndexTagAdd( LPNTXINDEX pIndex, LPTAGINFO pTag )
{
   LPCTXHEADER lpCTX = ( LPCTXHEADER ) pIndex->HeaderBuff;
   int iTags = HB_GET_LE_UINT16( lpCTX->ntags ), i;
   LPCTXTAGITEM pTagItem = ( LPCTXTAGITEM ) lpCTX->tags;

   for( i = 0; i < iTags; pTagItem++, i++ )
   {
      if( !hb_strnicmp( ( char * ) pTagItem->tag_name, pTag->TagName, NTX_MAX_TAGNAME ) )
         break;
   }
   if( i == iTags )
   {
      ++iTags;
      HB_PUT_LE_UINT16( lpCTX->ntags, iTags );
      strncpy( ( char * ) pTagItem->tag_name, pTag->TagName, NTX_MAX_TAGNAME );
   }
   HB_PUT_LE_UINT32( pTagItem->tag_header, pTag->HeadBlock );
   pIndex->Update = TRUE;
}

/*
 * delete tag from CTX header
 */
static void hb_ntxIndexTagDel( LPNTXINDEX pIndex, char * szTagName )
{
   LPCTXHEADER lpCTX = ( LPCTXHEADER ) pIndex->HeaderBuff;
   int iTags = HB_GET_LE_UINT16( lpCTX->ntags ), i;
   LPCTXTAGITEM pTagItem = ( LPCTXTAGITEM ) lpCTX->tags;

   for( i = 0; i < iTags; pTagItem++, i++ )
   {
      if( !hb_strnicmp( ( char * ) pTagItem->tag_name, szTagName, NTX_MAX_TAGNAME ) )
      {
         memmove( pTagItem, pTagItem + 1, ( iTags - i ) * NTX_TAGITEMSIZE );
         memset( pTagItem + iTags - 1, 0, NTX_TAGITEMSIZE );
         --iTags;
         HB_PUT_LE_UINT16( lpCTX->ntags, iTags );
         pIndex->Update = TRUE;
         break;
      }
   }
}

/*
 * find tag header block in CTX header
 */
static ULONG hb_ntxIndexTagFind( LPCTXHEADER lpCTX, char * szTagName )
{
   int iTags = HB_GET_LE_UINT16( lpCTX->ntags ), i;
   LPCTXTAGITEM pTagItem = ( LPCTXTAGITEM ) lpCTX->tags;

   for( i = 0; i < iTags; pTagItem++, i++ )
   {
      if( !hb_strnicmp( ( char * ) pTagItem->tag_name, szTagName, NTX_MAX_TAGNAME ) )
         return HB_GET_LE_UINT32( pTagItem->tag_header );
   }
   return NTX_DUMMYNODE;
}

/*
 * Write tag header
 */
static ERRCODE hb_ntxTagHeaderSave( LPTAGINFO pTag )
{
   LPNTXINDEX pIndex = pTag->Owner;
   NTXHEADER Header;
   int iSize = 12, type, version = 0;
   ULONG next = 0;

   if( pIndex->Compound )
   {
      if( !pTag->HeadBlock )
      {
         pTag->HeadBlock = hb_ntxPageGetFree( pTag );
         if( !pTag->HeadBlock )
            return FAILURE;
         hb_ntxIndexTagAdd( pIndex, pTag );
      }
   }
   else
   {
      if( pTag->HeadBlock )
      {
         hb_ntxPageAddFree( pTag, pTag->HeadBlock );
         pTag->HeadBlock = 0;
         pIndex->Update = TRUE;
      }
      pIndex->Version++;
      version = pIndex->Version &= 0xffff;
      next = pIndex->NextAvail;
   }

   type = NTX_FLAG_DEFALUT |
      ( pTag->ForExpr ? NTX_FLAG_FORITEM : 0 ) |
      ( pTag->Partial ? NTX_FLAG_PARTIAL | NTX_FLAG_FORITEM : 0 ) |
      ( pIndex->Owner->bLockType == DB_DBFLOCK_CL53EXT ? NTX_FLAG_EXTLOCK : 0 ) |
      ( pTag->Partial  ? NTX_FLAG_PARTIAL | NTX_FLAG_FORITEM : 0 ) |
      /* non CLipper flags */
      ( pTag->Custom   ? NTX_FLAG_CUSTOM : 0 ) |
      ( pTag->ChgOnly  ? NTX_FLAG_CHGONLY : 0 ) |
      ( pTag->Template ? NTX_FLAG_TEMPLATE : 0 ) |
      ( pTag->MultiKey ? NTX_FLAG_MULTIKEY : 0 ) |
      ( pTag->fSortRec ? NTX_FLAG_SORTRECNO : 0 ) |
      ( pIndex->LargeFile ? NTX_FLAG_LARGEFILE : 0 );

   HB_PUT_LE_UINT16( Header.type, type );
   HB_PUT_LE_UINT16( Header.version, version );
   HB_PUT_LE_UINT32( Header.root, pTag->RootBlock );
   HB_PUT_LE_UINT32( Header.next_page, next );

   if( pIndex->Update )
   {
      memset( ( BYTE * ) &Header + 12, 0, sizeof( NTXHEADER ) - 12 );

      HB_PUT_LE_UINT16( Header.item_size, pTag->KeyLength + 8 );
      HB_PUT_LE_UINT16( Header.key_size,  pTag->KeyLength );
      HB_PUT_LE_UINT16( Header.key_dec,   pTag->KeyDec );
      HB_PUT_LE_UINT16( Header.max_item,  pTag->MaxKeys );
      HB_PUT_LE_UINT16( Header.half_page, pTag->MaxKeys >> 1 );
      Header.unique[0]  = pTag->UniqueKey ? 1 : 0;
      Header.descend[0] = pTag->AscendKey ? 0 : 1;
      Header.custom[0]  = pTag->Custom    ? 1 : 0;
      strncpy( ( char * ) Header.key_expr, pTag->KeyExpr, NTX_MAX_EXP );
      if( pTag->ForExpr )
         strncpy( ( char * ) Header.for_expr, pTag->ForExpr, NTX_MAX_EXP );
      if( pTag->fTagName )
         strncpy( ( char * ) Header.tag_name, pTag->TagName, NTX_MAX_TAGNAME );
      iSize = sizeof( NTXHEADER );
   }

   if( !hb_ntxBlockWrite( pIndex, pTag->HeadBlock, ( BYTE * ) &Header, iSize ) )
      return FAILURE;
   pTag->HdrChanged = FALSE;
   pIndex->Changed = pIndex->Compound;
   pIndex->fFlush = TRUE;
   return SUCCESS;
}

/*
 * create new index structure
 */
static LPNTXINDEX hb_ntxIndexNew( NTXAREAP pArea )
{
   LPNTXINDEX pIndex;

   pIndex = ( LPNTXINDEX ) hb_xgrab( sizeof( NTXINDEX ) );
   memset( pIndex, 0, sizeof( NTXINDEX ) );

   pIndex->DiskFile = FS_ERROR;
   pIndex->Owner = pArea;
   return pIndex;
}

/*
 * close the index file and free from memory index and tag structures
 */
static void hb_ntxIndexFree( LPNTXINDEX pIndex )
{
   hb_ntxFreePageBuffer( pIndex );
   if( pIndex->iTags )
   {
      int i;
      for( i = 0; i < pIndex->iTags; i++ )
         hb_ntxTagFree( pIndex->lpTags[i] );
      hb_xfree( pIndex->lpTags );
   }
   if( pIndex->HeaderBuff )
      hb_xfree( pIndex->HeaderBuff );
   if( pIndex->DiskFile != FS_ERROR )
   {
      hb_fsClose( pIndex->DiskFile );
      if( pIndex->fDelete )
      {
         hb_fsDelete( ( BYTE * ) ( pIndex->RealName ?
                                   pIndex->RealName : pIndex->IndexName ) );
      }
   }
   if( pIndex->IndexName )
      hb_xfree( pIndex->IndexName );
   if( pIndex->RealName )
      hb_xfree( pIndex->RealName );
   hb_xfree( pIndex );
}

/*
 * Write tag header
 */
static ERRCODE hb_ntxIndexHeaderSave( LPNTXINDEX pIndex )
{
   if( pIndex->Compound )
   {
      LPCTXHEADER lpCTX = ( LPCTXHEADER ) pIndex->HeaderBuff;
      int iSize = pIndex->Update ? NTXBLOCKSIZE : 16;
      USHORT type;

      type = NTX_FLAG_COMPOUND | ( pIndex->LargeFile ? NTX_FLAG_LARGEFILE : 0 );

      pIndex->Version++;
      HB_PUT_LE_UINT16( lpCTX->type, type );
      HB_PUT_LE_UINT16( lpCTX->ntags, pIndex->iTags );
      HB_PUT_LE_UINT32( lpCTX->version, pIndex->Version );
      HB_PUT_LE_UINT32( lpCTX->freepage, pIndex->NextAvail );
      HB_PUT_LE_UINT32( lpCTX->filesize, pIndex->TagBlock );

      if( !hb_ntxBlockWrite( pIndex, 0, ( BYTE * ) lpCTX, iSize ) )
         return FAILURE;
   }
   pIndex->Changed = pIndex->Update = FALSE;
   return SUCCESS;
}

/*
 * load new tags from index file
 */
static ERRCODE hb_ntxIndexLoad( LPNTXINDEX pIndex, char * szTagName )
{
   LPTAGINFO pTag;
   USHORT type;

   if( !pIndex->fValidHeader )
   {
      if( !pIndex->HeaderBuff )
         pIndex->HeaderBuff = ( BYTE * ) hb_xgrab( NTXBLOCKSIZE );
      if( !hb_ntxBlockRead( pIndex, 0, pIndex->HeaderBuff, NTXBLOCKSIZE ) )
         return FAILURE;
      pIndex->fValidHeader = TRUE;
   }

   type = HB_GET_LE_UINT16( pIndex->HeaderBuff );
#if !defined( HB_NTX_NOMULTITAG )
   pIndex->Compound = ( type & NTX_FLAG_COMPOUND ) != 0;
   if( pIndex->Compound )
   {
      BYTE tagbuffer[ NTXBLOCKSIZE ];
      LPCTXHEADER lpCTX = ( LPCTXHEADER ) pIndex->HeaderBuff;
      LPCTXTAGITEM pTagItem = ( LPCTXTAGITEM ) lpCTX->tags;
      ULONG ulBlock;
      int iTags;

      iTags = HB_GET_LE_UINT16( lpCTX->ntags );
      if( iTags > CTX_MAX_TAGS )
         return FAILURE;
      pIndex->Version = HB_GET_LE_UINT32( lpCTX->version );
      pIndex->NextAvail = HB_GET_LE_UINT32( lpCTX->freepage );
      pIndex->TagBlock = HB_GET_LE_UINT32( lpCTX->filesize );
      pIndex->LargeFile = ( type & NTX_FLAG_LARGEFILE ) != 0;

      for( pIndex->iTags = 0; pIndex->iTags < iTags; pTagItem++ )
      {
         ulBlock = HB_GET_LE_UINT32( pTagItem->tag_header );
         if( ulBlock == 0 || pTagItem->tag_name[ 0 ] <= 0x20 )
            return FAILURE;
         if( !hb_ntxBlockRead( pIndex, ulBlock, tagbuffer, NTXBLOCKSIZE ) )
            return FAILURE;
         pTag = hb_ntxTagLoad( pIndex, ulBlock, ( char * ) pTagItem->tag_name, tagbuffer );
         if( !pTag )
            return FAILURE;
         hb_ntxTagAdd( pIndex, pTag );
      }
   }
   else
#endif
   {
      pTag = hb_ntxTagLoad( pIndex, 0, szTagName, pIndex->HeaderBuff );
      if( !pTag )
         return FAILURE;
      hb_ntxTagAdd( pIndex, pTag );
   }

   return SUCCESS;
}

/*
 * read index header and check for concurrent access
 */
static ERRCODE hb_ntxIndexHeaderRead( LPNTXINDEX pIndex )
{
   USHORT type;

   if( !pIndex->HeaderBuff )
      pIndex->HeaderBuff = ( BYTE * ) hb_xgrab( NTXBLOCKSIZE );

   if( !hb_ntxBlockRead( pIndex, 0, pIndex->HeaderBuff, NTXBLOCKSIZE ) )
      return FAILURE;

   type = HB_GET_LE_UINT16( pIndex->HeaderBuff );
   if( ( type & NTX_FLAG_COMPOUND ) != 0 )
   {
#if defined( HB_NTX_NOMULTITAG )
      hb_ntxErrorRT( pIndex->Owner, EG_CORRUPTION, EDBF_CORRUPT,
                     pIndex->IndexName, hb_fsError(), 0 );
      return FAILURE;
#else
      LPCTXHEADER lpCTX = ( LPCTXHEADER ) pIndex->HeaderBuff;
      ULONG ulVersion, ulNext;
      /* USHORT usTags = HB_GET_LE_UINT16( lpCTX->ntags ); */

      ulVersion = HB_GET_LE_UINT32( lpCTX->version );
      ulNext = HB_GET_LE_UINT32( lpCTX->freepage );
      pIndex->TagBlock = HB_GET_LE_UINT32( lpCTX->filesize );

      if( pIndex->Version != ulVersion || pIndex->NextAvail != ulNext ||
          !pIndex->Compound )
      {
         int i;
         hb_ntxDiscardBuffers( pIndex );
         pIndex->Version = ulVersion;
         pIndex->NextAvail = ulNext;
         pIndex->Compound = TRUE;
         for( i = 1; i < pIndex->iTags; i++ )
         {
            pIndex->lpTags[ i ]->HeadBlock =
                     hb_ntxIndexTagFind( lpCTX, pIndex->lpTags[ i ]->TagName );
            if( !pIndex->lpTags[ i ]->HeadBlock )
               pIndex->lpTags[ i ]->RootBlock = 0;
         }
      }
#endif
   }
   else
   {
      LPNTXHEADER lpNTX = ( LPNTXHEADER ) pIndex->HeaderBuff;
      ULONG ulRootPage, ulVersion;
      LPTAGINFO pTag;

      if( pIndex->Compound )
      {
         hb_ntxErrorRT( pIndex->Owner, EG_CORRUPTION, EDBF_CORRUPT,
                        pIndex->IndexName, hb_fsError(), 0 );
         return FAILURE;
      }
      pTag = pIndex->iTags ? pIndex->lpTags[0] : NULL;

      ulVersion = HB_GET_LE_UINT16( lpNTX->version );
      ulRootPage = HB_GET_LE_UINT32( lpNTX->root );
      pIndex->NextAvail = HB_GET_LE_UINT32( lpNTX->next_page );
      if( pIndex->Version != ulVersion || ( pTag &&
          ( pTag->Signature != type || ulRootPage != pTag->RootBlock ) ) )
      {
         hb_ntxDiscardBuffers( pIndex );
         pIndex->Version = ulVersion;
         if( pTag )
         {
            pTag->RootBlock = ulRootPage;
            pTag->Signature = type;
            hb_ntxTagUpdateFlags( pTag );
         }
      }
   }
   return SUCCESS;
}

/*
 * write modified pages to index file
 */
static void hb_ntxIndexFlush( LPNTXINDEX pIndex )
{
   while( pIndex->pChanged )
   {
      LPPAGEINFO pPage = pIndex->pChanged;
      pIndex->pChanged = pPage->pNext;
      if( pPage->Changed )
      {
         hb_ntxPageSave( pIndex, pPage );
         ++pPage->iUsed;
         hb_ntxPageRelease( pIndex->lpTags[0], pPage );
      }
      else
         hb_errInternal( 9999, "hb_ntxIndexFlush: unchaged page in the list.", "", "" );
   }

   if( pIndex->Compound )
   {
      int i;

      for( i = 0; i < pIndex->iTags; i++ )
         if( pIndex->lpTags[ i ]->HdrChanged )
            hb_ntxTagHeaderSave( pIndex->lpTags[ i ] );
      if( pIndex->Changed )
         hb_ntxIndexHeaderSave( pIndex );
   }
   else
   {
      if( pIndex->Changed || pIndex->lpTags[ 0 ]->HdrChanged )
         hb_ntxTagHeaderSave( pIndex->lpTags[ 0 ] );
   }
}

/*
 * lock index for reading (shared lock)
 */
static BOOL hb_ntxIndexLockRead( LPNTXINDEX pIndex )
{
   BOOL fOK;

   if( pIndex->lockRead > 0 || pIndex->lockWrite > 0 || !pIndex->fShared )
   {
      fOK = TRUE;
      pIndex->lockRead++;
   }
   else
   {
      fOK = hb_dbfLockIdxFile( pIndex->DiskFile, pIndex->Owner->bLockType,
                        FL_LOCK | FLX_SHARED | FLX_WAIT, &pIndex->ulLockPos );
      /* if fOK then check VERSION field in NTXHEADER and
       * if it has been changed then discard all page buffers
       */
      if( fOK )
      {
         pIndex->lockRead++;
         if( hb_ntxIndexHeaderRead( pIndex ) != SUCCESS )
         {
            pIndex->lockRead--;
            hb_dbfLockIdxFile( pIndex->DiskFile, pIndex->Owner->bLockType,
                               FL_UNLOCK, &pIndex->ulLockPos );
            return FALSE;
         }
      }
   }
   if( !fOK )
      hb_ntxErrorRT( pIndex->Owner, EG_LOCK, EDBF_LOCK, pIndex->IndexName, hb_fsError(), 0 );

   return fOK;
}

/*
 * lock index for writing (exclusive lock)
 */
static BOOL hb_ntxIndexLockWrite( LPNTXINDEX pIndex, BOOL fCheck )
{
   BOOL fOK;

   if( pIndex->fReadonly )
      hb_errInternal( 9101, "hb_ntxIndexLockWrite: readonly index.", "", "" );

   if( pIndex->lockRead )
      hb_errInternal( 9105, "hb_ntxIndexLockWrite: writeLock after readLock.", "", "" );

   if( pIndex->lockWrite > 0 || !pIndex->fShared )
   {
      fOK = TRUE;
      pIndex->lockWrite++;
   }
   else
   {
      fOK = hb_dbfLockIdxFile( pIndex->DiskFile, pIndex->Owner->bLockType,
                               FL_LOCK | FLX_WAIT, &pIndex->ulLockPos );
      /* if fOK then check VERSION field in NTXHEADER and
       * if it has been changed then discard all page buffers
       */
      if( fOK )
      {
         pIndex->lockWrite++;
         if( fCheck && hb_ntxIndexHeaderRead( pIndex ) != SUCCESS )
         {
            pIndex->lockWrite--;
            hb_dbfLockIdxFile( pIndex->DiskFile, pIndex->Owner->bLockType,
                               FL_UNLOCK, &pIndex->ulLockPos );
            return FALSE;
         }
      }
   }
   if( !fOK )
      hb_ntxErrorRT( pIndex->Owner, EG_LOCK, EDBF_LOCK, pIndex->IndexName, hb_fsError(), 0 );

   return fOK;
}

/*
 * remove index read lock (shared lock)
 */
static BOOL hb_ntxIndexUnLockRead( LPNTXINDEX pIndex )
{
   BOOL fOK;

#ifdef HB_NTX_DEBUG
   int i;
   for( i = 0; i < pIndex->iTags; i++ )
      hb_ntxTagCheckBuffers( pIndex->lpTags[ i ] );
#endif

   pIndex->lockRead--;
   if( pIndex->lockRead < 0 )
      hb_errInternal( 9106, "hb_ntxIndexUnLockRead: bad count of locks.", "", "" );

   if( pIndex->lockRead || pIndex->lockWrite || !pIndex->fShared )
   {
      fOK = TRUE;
   }
   else
   {
      pIndex->fValidHeader = FALSE;
      fOK = hb_dbfLockIdxFile( pIndex->DiskFile, pIndex->Owner->bLockType,
                               FL_UNLOCK, &pIndex->ulLockPos );
   }
   if( !fOK )
      hb_errInternal( 9108, "hb_ntxIndexUnLockRead: unlock error.", "", "" );

   return fOK;
}

/*
 * remove index write lock (exclusive lock)
 */
static BOOL hb_ntxIndexUnLockWrite( LPNTXINDEX pIndex )
{
   BOOL fOK;

#ifdef HB_NTX_DEBUG
   int i;
   for( i = 0; i < pIndex->iTags; i++ )
      hb_ntxTagCheckBuffers( pIndex->lpTags[ i ] );
#endif

   if( pIndex->lockWrite <= 0 )
      hb_errInternal( 9106, "hb_ntxIndexUnLockWrite: bad count of locks.", "", "" );
   if( pIndex->lockRead )
      hb_errInternal( 9105, "hb_ntxIndexUnLockWrite: writeUnLock before readUnLock.", "", "" );

   hb_ntxIndexFlush( pIndex );
   pIndex->lockWrite--;

   if( pIndex->lockWrite || !pIndex->fShared )
   {
      fOK = TRUE;
   }
   else
   {
      pIndex->fValidHeader = FALSE;
      fOK = hb_dbfLockIdxFile( pIndex->DiskFile, pIndex->Owner->bLockType,
                               FL_UNLOCK, &pIndex->ulLockPos );
   }
   if( !fOK )
      hb_errInternal( 9108, "hb_ntxIndexUnLockWrite: unlock error.", "", "" );

   return fOK;
}

/*
 * lock tag for reading (shared lock)
 */
static BOOL hb_ntxTagLockRead( LPTAGINFO pTag )
{
   BOOL fOK = FALSE;

   if( hb_ntxIndexLockRead( pTag->Owner ) )
   {
      fOK = hb_ntxTagHeaderCheck( pTag );
      if( !fOK )
      {
         hb_ntxIndexUnLockRead( pTag->Owner );
         hb_ntxErrorRT( pTag->Owner->Owner, EG_CORRUPTION, EDBF_CORRUPT,
                        pTag->Owner->IndexName, 0, 0 );
      }
   }
   return fOK;
}

/*
 * lock tag for writing (exclusive lock)
 */
static BOOL hb_ntxTagLockWrite( LPTAGINFO pTag )
{
   BOOL fOK = FALSE;

   if( hb_ntxIndexLockWrite( pTag->Owner, TRUE ) )
   {
      fOK = hb_ntxTagHeaderCheck( pTag );
      if( !fOK )
      {
         hb_ntxIndexUnLockWrite( pTag->Owner );
         hb_ntxErrorRT( pTag->Owner->Owner, EG_CORRUPTION, EDBF_CORRUPT,
                        pTag->Owner->IndexName, 0, 0 );
      }
   }
   return fOK;
}

/*
 * remove tag read lock (shared lock)
 */
static BOOL hb_ntxTagUnLockRead( LPTAGINFO pTag )
{
   return hb_ntxIndexUnLockRead( pTag->Owner );
}

/*
 * remove tag write lock (exclusive lock)
 */
static BOOL hb_ntxTagUnLockWrite( LPTAGINFO pTag )
{
   return hb_ntxIndexUnLockWrite( pTag->Owner );
}

/*
 * retrive key from page
 */
static void hb_ntxPageGetKey( LPPAGEINFO pPage, USHORT uiKey, LPKEYINFO pKey, USHORT uiLen )
{
   if( uiKey < pPage->uiKeys )
   {
      memcpy( pKey->key, hb_ntxGetKeyVal( pPage, uiKey ), uiLen );
      pKey->Xtra = hb_ntxGetKeyRec( pPage, uiKey );
      pKey->Tag = pPage->Page;
   }
   else
   {
      pKey->Xtra = pKey->Tag = 0;
   }
}

/*
 * set next page and key in page path
 */
static void hb_ntxTagSetPageStack( LPTAGINFO pTag, ULONG ulPage, USHORT uiKey )
{
   if( pTag->stackLevel == pTag->stackSize )
   {
      if( pTag->stackSize == 0 )
      {
         pTag->stackSize = NTX_STACKSIZE;
         pTag->stack = (LPTREESTACK) hb_xgrab( sizeof(TREE_STACK) * NTX_STACKSIZE );
      }
      else
      {
         pTag->stackSize += NTX_STACKSIZE;
         pTag->stack = ( LPTREESTACK ) hb_xrealloc( pTag->stack,
                                    sizeof( TREE_STACK ) * pTag->stackSize );
      }
   }
   pTag->stack[ pTag->stackLevel ].page = ulPage;
   pTag->stack[ pTag->stackLevel++ ].ikey = uiKey;
}

/*
 * go down from the given index page to the first key
 */
static LPPAGEINFO hb_ntxPageTopMove( LPTAGINFO pTag, ULONG ulPage )
{
   LPPAGEINFO pPage = NULL;

   do
   {
      if( pPage )
         hb_ntxPageRelease( pTag, pPage );
      pPage = hb_ntxPageLoad( pTag, ulPage );
      if( ! pPage )
         return NULL;
#ifdef HB_NTX_DEBUG_EXT
      if( pPage->uiKeys == 0 && pTag->stackLevel > 0 )
      {
         hb_errInternal( 9201, "hb_ntxPageTopMove: index corrupted.", "", "" );
         return NULL;
      }
#endif
      ulPage = hb_ntxGetKeyPage( pPage, 0 );
      hb_ntxTagSetPageStack( pTag, pPage->Page, 0 );
   }
   while( ulPage );

   return pPage;
}

/*
 * go down from the given index page to the last key
 */
static LPPAGEINFO hb_ntxPageBottomMove( LPTAGINFO pTag, ULONG ulPage )
{
   LPPAGEINFO pPage = NULL;

   do
   {
      if( pPage )
         hb_ntxPageRelease( pTag, pPage );
      pPage = hb_ntxPageLoad( pTag, ulPage );
      if( ! pPage )
         return NULL;
#ifdef HB_NTX_DEBUG_EXT
      if( pPage->uiKeys == 0 && pTag->stackLevel > 0 )
      {
         hb_errInternal( 9201, "hb_ntxPageBottomMove: index corrupted.", "", "" );
         return NULL;
      }
#endif
      ulPage = hb_ntxGetKeyPage( pPage, pPage->uiKeys );
      hb_ntxTagSetPageStack( pTag, pPage->Page, pPage->uiKeys -
                                    ( ulPage || pPage->uiKeys == 0 ? 0 : 1 ) );
   }
   while( ulPage );

   return pPage;
}

/*
 * set page path to the first key in tag
 */
static BOOL hb_ntxTagTopKey( LPTAGINFO pTag )
{
   LPPAGEINFO pPage;
   int iKeys;

   pTag->stackLevel = 0;
   pPage = hb_ntxPageTopMove( pTag, 0 );
   if( ! pPage )
      return FALSE;
   hb_ntxPageGetKey( pPage, 0, pTag->CurKeyInfo, pTag->KeyLength );
   iKeys = pPage->uiKeys;
   hb_ntxPageRelease( pTag, pPage );
   return iKeys != 0;
}

/*
 * set page path to the last key in tag
 */
static BOOL hb_ntxTagBottomKey( LPTAGINFO pTag )
{
   LPPAGEINFO pPage;
   int iKeys;

   pTag->stackLevel = 0;
   pPage = hb_ntxPageBottomMove( pTag, 0 );
   if( ! pPage )
      return FALSE;
   hb_ntxPageGetKey( pPage, pTag->stack[ pTag->stackLevel - 1 ].ikey,
                     pTag->CurKeyInfo, pTag->KeyLength );
   iKeys = pPage->uiKeys;
   hb_ntxPageRelease( pTag, pPage );
   return iKeys != 0;
}

/*
 * update page path to the next key in tag
 */
static BOOL hb_ntxTagNextKey( LPTAGINFO pTag )
{
   int iLevel = pTag->stackLevel - 1;
   LPPAGEINFO pPage;
   ULONG ulPage = 0;

   if( iLevel >= 0 )
   {
      pPage = hb_ntxPageLoad( pTag, pTag->stack[ iLevel ].page );
      if( ! pPage )
         return FALSE;
      if( pTag->stack[ iLevel ].ikey < pPage->uiKeys )
         ulPage = hb_ntxGetKeyPage( pPage, pTag->stack[ iLevel ].ikey + 1 );
      if( ulPage || pTag->stack[ iLevel ].ikey + 1 < pPage->uiKeys )
      {
         pTag->stack[ iLevel ].ikey++;
         if( ulPage )
         {
            hb_ntxPageRelease( pTag, pPage );
            pPage = hb_ntxPageTopMove( pTag, ulPage );
            if( ! pPage )
               return FALSE;
         }
      }
      else
      {
         while( --iLevel >= 0 )
         {
            hb_ntxPageRelease( pTag, pPage );
            pPage = hb_ntxPageLoad( pTag, pTag->stack[ iLevel ].page );
            if( ! pPage )
               return FALSE;
            if( pTag->stack[ iLevel ].ikey < pPage->uiKeys )
               break;
         }
         if( iLevel < 0 )
         {
            hb_ntxPageRelease( pTag, pPage );
            return FALSE;
         }
         pTag->stackLevel = iLevel + 1;
      }
      hb_ntxPageGetKey( pPage, pTag->stack[ pTag->stackLevel - 1 ].ikey,
                        pTag->CurKeyInfo, pTag->KeyLength );
      hb_ntxPageRelease( pTag, pPage );
      return TRUE;
   }
   return FALSE;
}

/*
 * update page path to the previous key in tag
 */
static BOOL hb_ntxTagPrevKey( LPTAGINFO pTag )
{
   int iLevel = pTag->stackLevel - 1;
   LPPAGEINFO pPage;
   ULONG ulPage;

   if( iLevel >= 0 )
   {
      pPage = hb_ntxPageLoad( pTag, pTag->stack[ iLevel ].page );
      if( ! pPage )
         return FALSE;
      ulPage = hb_ntxGetKeyPage( pPage, pTag->stack[ iLevel ].ikey );
      if( ulPage )
      {
         hb_ntxPageRelease( pTag, pPage );
         pPage = hb_ntxPageBottomMove( pTag, ulPage );
         if( ! pPage )
            return FALSE;
      }
      else if( pTag->stack[ iLevel ].ikey )
      {
         pTag->stack[ iLevel ].ikey--;
      }
      else
      {
         while( --iLevel >= 0 )
         {
            hb_ntxPageRelease( pTag, pPage );
            pPage = hb_ntxPageLoad( pTag, pTag->stack[ iLevel ].page );
            if( ! pPage )
               return FALSE;
            if( pTag->stack[ iLevel ].ikey )
            {
               pTag->stack[ iLevel ].ikey--;
               break;
            }
         }
         if( iLevel < 0 )
         {
            hb_ntxPageRelease( pTag, pPage );
            return FALSE;
         }
         pTag->stackLevel = iLevel + 1;
      }
      hb_ntxPageGetKey( pPage, pTag->stack[ pTag->stackLevel - 1 ].ikey,
                        pTag->CurKeyInfo, pTag->KeyLength );
      hb_ntxPageRelease( pTag, pPage );
      return TRUE;
   }
   return FALSE;
}

/*
 * find a key value in page
 */
static int hb_ntxPageKeyFind( LPTAGINFO pTag, LPPAGEINFO pPage,
                              char* key, SHORT keylen, BOOL fNext,
                              ULONG ulRecNo, BOOL *fStop )
{
   SHORT iLast = -1, iBegin = 0, iEnd = pPage->uiKeys - 1, k, i;

   *fStop = FALSE;
   while( iBegin <= iEnd )
   {
      i = ( iBegin + iEnd ) >> 1;
      k = hb_ntxValCompare( pTag, key, keylen, hb_ntxGetKeyVal( pPage, i ),
                            pTag->KeyLength, FALSE );
      if( k == 0 )
      {
         if( ulRecNo != 0 && pTag->fSortRec )
         {
            ULONG ulRec = hb_ntxGetKeyRec( pPage, i );
            if( ulRecNo < ulRec )
               k = -1;
            else if( ulRecNo > ulRec )
               k = 1;
            else
            {
               *fStop = TRUE;
               return i;
            }
         }
      }
      else if( !pTag->AscendKey )
         k = -k;
      if( fNext ? k >= 0 : k > 0 )
         iBegin = i + 1;
      else
      {
         if( k == 0 && !ulRecNo )
            *fStop = TRUE;
         iLast = i;
         iEnd = i - 1;
      }
   }
   return iLast >= 0 ? iLast : pPage->uiKeys;
}

/*
 * find a record in page starting from given key
 */
static BOOL hb_ntxPageFindRecNo( LPPAGEINFO pPage, int * iStart, ULONG ulRecno )
{
   int iKey = *iStart;
   while( iKey < pPage->uiKeys )
   {
      if( hb_ntxGetKeyRec( pPage, iKey ) == ulRecno )
      {
         *iStart = iKey;
         return TRUE;
      }
      iKey++;
   }
   return FALSE;
}

/*
 * set page path to given key in tag
 */
static BOOL hb_ntxTagKeyFind( LPTAGINFO pTag, LPKEYINFO pKey, USHORT uiLen )
{
   LPPAGEINFO pPage = NULL;
   ULONG ulPage = 0, ulRecNo = 0;
   int iKey;
   BOOL fStop = FALSE, fNext = FALSE, fPrev = FALSE, fOut = FALSE;

   if( pKey->Tag == NTX_MAX_REC_NUM )          /* for key add */
   {
      if( pTag->fSortRec )
         ulRecNo = pKey->Xtra;
      else
         fNext = TRUE;
   }
   else if( pKey->Xtra == NTX_MAX_REC_NUM )    /* for seek last */
      fNext = fPrev = TRUE;
   else if( pKey->Xtra != NTX_IGNORE_REC_NUM ) /* for key del and current key */
      ulRecNo = pKey->Xtra;
   /* else -> normal seek */

   pTag->stackLevel = 0;
   do
   {
      if( pPage )
         hb_ntxPageRelease( pTag, pPage );
      pPage = hb_ntxPageLoad( pTag, ulPage );
      if( ! pPage )
         return FALSE;
      iKey = hb_ntxPageKeyFind( pTag, pPage, pKey->key, uiLen, fNext, ulRecNo, &fStop );
      hb_ntxTagSetPageStack( pTag, pPage->Page, iKey );
      if( fStop && ulRecNo && pTag->fSortRec )
         break;
      ulPage = hb_ntxGetKeyPage( pPage, iKey );
   } while( ulPage != 0 );

   if( ulRecNo && !pTag->fSortRec ) /* small hack - should speedup in some cases */
   {
      if( hb_ntxPageFindRecNo( pPage, &iKey, ulRecNo ) )
         pTag->stack[ pTag->stackLevel - 1 ].ikey = iKey;
   }

   hb_ntxPageGetKey( pPage, iKey, pTag->CurKeyInfo, pTag->KeyLength );
   hb_ntxPageRelease( pTag, pPage );

   if( ulRecNo )
   {
      if( !pTag->fSortRec )
      {
         fStop = TRUE;
         while( fStop && ulRecNo != pTag->CurKeyInfo->Xtra )
         {
            if( ! hb_ntxTagNextKey( pTag ) ) /* Tag EOF */
            {
               fOut = TRUE;
               fStop = FALSE;
            }
            else
            {
               fStop = hb_ntxValCompare( pTag, pKey->key, uiLen,
                                         pTag->CurKeyInfo->key, pTag->KeyLength,
                                         FALSE ) == 0;
            }
         }
      }
   }
   else if( fPrev )
   {
      if( !hb_ntxTagPrevKey( pTag ) )
      {
         fOut = TRUE;
         fStop = FALSE;
      }
      else
      {
         fStop = hb_ntxValCompare( pTag, pKey->key, uiLen, pTag->CurKeyInfo->key,
                                   pTag->KeyLength, FALSE ) == 0;
      }
   }
   else if( !fNext && !fStop && pTag->CurKeyInfo->Xtra == 0 )
   {
      if( ! hb_ntxTagNextKey( pTag ) ) /* Tag EOF */
      {
         fOut = TRUE;
         fStop = FALSE;
      }
      else
      {
         fStop = hb_ntxValCompare( pTag, pKey->key, uiLen,
                                   pTag->CurKeyInfo->key, pTag->KeyLength,
                                   FALSE ) == 0;
      }
   }

   pTag->TagBOF = pTag->TagEOF = fOut || pTag->CurKeyInfo->Xtra == 0;

   return fStop;
}

/*
 * set key in the given tag page
 */
static void hb_ntxPageKeySet( LPTAGINFO pTag, LPPAGEINFO pPage, USHORT uiPos,
                              ULONG ulPage, ULONG ulRec, char * keyVal )
{
   hb_ntxSetKeyPage( pPage, uiPos, ulPage );
   hb_ntxSetKeyRec( pPage, uiPos, ulRec );
   memcpy( hb_ntxGetKeyVal( pPage, uiPos ), keyVal, pTag->KeyLength );
   pPage->Changed = TRUE;
}

/*
 * add key to tag page
 */
static void hb_ntxPageKeyAdd( LPTAGINFO pTag, LPPAGEINFO pPage, USHORT uiPos,
                              ULONG ulPage, ULONG ulRec, char * keyVal )
{
   USHORT u, ntmp = hb_ntxGetKeyOffset( pPage, pPage->uiKeys + 1 );

   /* TODO?: update to keep last key pointer fixed */
   for( u = pPage->uiKeys + 1; u > uiPos; u-- )
   {
      hb_ntxSetKeyOffset( pPage, u, hb_ntxGetKeyOffset( pPage, u - 1 ) );
   }
   hb_ntxSetKeyOffset( pPage, uiPos, ntmp );
   pPage->uiKeys++;

   hb_ntxPageKeySet( pTag, pPage, uiPos, ulPage, ulRec, keyVal );
#ifdef HB_NTX_DEBUG
   hb_ntxPageCheckKeys( pPage, pTag, uiPos, 41 );
#endif
}

/*
 * del key from the page
 */
static void hb_ntxPageKeyDel( LPPAGEINFO pPage, USHORT uiPos )
{
   USHORT u, ntmp = hb_ntxGetKeyOffset( pPage, uiPos );

   /* TODO?: update to keep last key pointer fixed */
   for( u = uiPos; u < pPage->uiKeys; u++ )
      hb_ntxSetKeyOffset( pPage, u, hb_ntxGetKeyOffset( pPage, u + 1 ) );
   hb_ntxSetKeyOffset( pPage, pPage->uiKeys, ntmp );

   pPage->uiKeys--;
   pPage->Changed = TRUE;
}

/*
 * split single page into two and return key to the new one
 */
static LPKEYINFO hb_ntxPageSplit( LPTAGINFO pTag, LPPAGEINFO pPage,
                                  LPKEYINFO pKey, USHORT uiPos )
{
   LPPAGEINFO pNewPage = hb_ntxPageNew( pTag, FALSE );
   LPKEYINFO pKeyNew;
   USHORT uiKeys = pPage->uiKeys + 1, uiLen = pTag->KeyLength + 8,
          i, j, u, uiHalf;
   ULONG ulPage;

   if( ! pNewPage )
      return NULL;
   pKeyNew = hb_ntxKeyNew( NULL, pTag->KeyLength );

   uiHalf = uiKeys >> 1;

   j = 0;
   while( pNewPage->uiKeys < uiHalf )
   {
      if( pNewPage->uiKeys == uiPos )
      {
         hb_ntxSetKeyPage( pNewPage, pNewPage->uiKeys, pKey->Tag );
         hb_ntxSetKeyRec( pNewPage, pNewPage->uiKeys, pKey->Xtra );
         memcpy( hb_ntxGetKeyVal( pNewPage, pNewPage->uiKeys ), pKey->key, pTag->KeyLength );
      }
      else
      {
         memcpy( hb_ntxGetKeyPtr( pNewPage, pNewPage->uiKeys ),
                 hb_ntxGetKeyPtr( pPage, j ), uiLen );
         j++;
      }
      pNewPage->uiKeys++;
   }

   if( uiHalf == uiPos )
   {
      pKeyNew->Xtra = pKey->Xtra;
      memcpy( pKeyNew->key, pKey->key, pTag->KeyLength );
      hb_ntxSetKeyPage( pNewPage, pNewPage->uiKeys, pKey->Tag );
   }
   else
   {
      pKeyNew->Xtra = hb_ntxGetKeyRec( pPage, j );
      memcpy( pKeyNew->key, hb_ntxGetKeyVal( pPage, j ), pTag->KeyLength );
      hb_ntxSetKeyPage( pNewPage, pNewPage->uiKeys, hb_ntxGetKeyPage( pPage, j ) );
      j++;
   }
   pKeyNew->Tag = pNewPage->Page;

   i = 0;
   while( ++uiHalf < uiKeys )
   {
      if( uiHalf == uiPos )
      {
         hb_ntxSetKeyPage( pPage, i, pKey->Tag );
         hb_ntxSetKeyRec( pPage, i, pKey->Xtra );
         memcpy( hb_ntxGetKeyVal( pPage, i ), pKey->key, pTag->KeyLength );
      }
      else
      {
         u = hb_ntxGetKeyOffset( pPage, j );
         hb_ntxSetKeyOffset( pPage, j, hb_ntxGetKeyOffset( pPage, i ) );
         hb_ntxSetKeyOffset( pPage, i, u );
         j++;
      }
      i++;
   }
   ulPage = hb_ntxGetKeyPage( pPage, pPage->uiKeys );
   hb_ntxSetKeyPage( pPage, pPage->uiKeys, 0 );
   hb_ntxSetKeyPage( pPage, i, ulPage );
   pPage->uiKeys = i;

   pPage->Changed = pNewPage->Changed = TRUE;
#ifdef HB_NTX_DEBUG
   hb_ntxPageCheckKeys( pNewPage, pTag, uiPos, 1 );
   hb_ntxPageCheckKeys( pPage, pTag, uiPos - pNewPage->uiKeys, 2 );
#endif
   hb_ntxPageRelease( pTag, pNewPage );

   return pKeyNew;
}

/*
 * join two neighbour pages and update the parent page key
 */
static void hb_ntxPageJoin( LPTAGINFO pTag, LPPAGEINFO pBasePage, USHORT uiPos,
                            LPPAGEINFO pFirst, LPPAGEINFO pLast )
{
   USHORT uiLen = pTag->KeyLength + 8, i;

   hb_ntxSetKeyRec( pFirst, pFirst->uiKeys, hb_ntxGetKeyRec( pBasePage, uiPos ) );
   memcpy( hb_ntxGetKeyVal( pFirst, pFirst->uiKeys ),
           hb_ntxGetKeyVal( pBasePage, uiPos ), pTag->KeyLength );
   pFirst->uiKeys++;
   hb_ntxPageKeyDel( pBasePage, uiPos );
   hb_ntxSetKeyPage( pBasePage, uiPos, pFirst->Page );
   for( i = 0; i < pLast->uiKeys; i++ )
   {
      memcpy( hb_ntxGetKeyPtr( pFirst, pFirst->uiKeys ),
              hb_ntxGetKeyPtr( pLast, i ), uiLen );
      pFirst->uiKeys++;
   }
   hb_ntxSetKeyPage( pFirst, pFirst->uiKeys, hb_ntxGetKeyPage( pLast, pLast->uiKeys ) );
   pLast->uiKeys = 0;
   hb_ntxPageFree( pTag, pLast );
   pFirst->Changed = pLast->Changed = TRUE;
#ifdef HB_NTX_DEBUG
   hb_ntxPageCheckKeys( pBasePage, pTag, uiPos, 11 );
   hb_ntxPageCheckKeys( pFirst, pTag, 0, 12 );
#endif
}

/*
 * balance keys in two neighbour pages and update the parent page key
 */
static void hb_ntxBalancePages( LPTAGINFO pTag, LPPAGEINFO pBasePage, USHORT uiPos,
                                LPPAGEINFO pFirst, LPPAGEINFO pLast )
{
   USHORT uiLen = pTag->KeyLength + 8, n;
   int i, j, iMove = ( ( pFirst->uiKeys + pLast->uiKeys + 1 ) >> 1 ) - pFirst->uiKeys;

   /*
    * such situation should not exist even max keys, though it does not cost
    * much and I want to be able to call hb_ntxBalancePages in any case for
    * some advanced balancing
    */
   if( iMove == 0 )
      return;

#ifdef HB_NTX_DEBUG
   hb_ntxPageCheckKeys( pBasePage, pTag, uiPos, 31 );
   hb_ntxPageCheckKeys( pFirst, pTag, iMove, 32 );
   hb_ntxPageCheckKeys( pLast, pTag, iMove, 33 );
#endif

   if( iMove > 0 )
   {
      hb_ntxSetKeyRec( pFirst, pFirst->uiKeys, hb_ntxGetKeyRec( pBasePage, uiPos ) );
      memcpy( hb_ntxGetKeyVal( pFirst, pFirst->uiKeys ),
              hb_ntxGetKeyVal( pBasePage, uiPos ), pTag->KeyLength );
      pFirst->uiKeys++;
      i = 0;
      while( --iMove )
      {
         memcpy( hb_ntxGetKeyPtr( pFirst, pFirst->uiKeys ),
                 hb_ntxGetKeyPtr( pLast, i ), uiLen );
         pFirst->uiKeys++;
         i++;
      }
      hb_ntxSetKeyRec( pBasePage, uiPos, hb_ntxGetKeyRec( pLast, i ) );
      memcpy( hb_ntxGetKeyVal( pBasePage, uiPos ),
              hb_ntxGetKeyVal( pLast, i ), pTag->KeyLength );
      hb_ntxSetKeyPage( pFirst, pFirst->uiKeys, hb_ntxGetKeyPage( pLast, i ) );
      i++;
      pLast->uiKeys -= i;
      /* TODO?: update to keep last key pointer fixed */
      for( j = 0; j <= pLast->uiKeys; j++ )
      {
         n = hb_ntxGetKeyOffset( pLast, j );
         hb_ntxSetKeyOffset( pLast, j, hb_ntxGetKeyOffset( pLast, j + i ) );
         hb_ntxSetKeyOffset( pLast, j + i, n );
      }
   }
   else
   {
      /* TODO?: update to keep last key pointer fixed */
      for( j = pLast->uiKeys; j >= 0; j-- )
      {
         n = hb_ntxGetKeyOffset( pLast, j - iMove );
         hb_ntxSetKeyOffset( pLast, j - iMove, hb_ntxGetKeyOffset( pLast, j ) );
         hb_ntxSetKeyOffset( pLast, j, n );
      }
      i = -iMove - 1;
      hb_ntxSetKeyRec( pLast, i, hb_ntxGetKeyRec( pBasePage, uiPos ) );
      memcpy( hb_ntxGetKeyVal( pLast, i ),
              hb_ntxGetKeyVal( pBasePage, uiPos ), pTag->KeyLength );
      hb_ntxSetKeyPage( pLast, i, hb_ntxGetKeyPage( pFirst, pFirst->uiKeys ) );
      while( --i >= 0 )
      {
         pFirst->uiKeys--;
         memcpy( hb_ntxGetKeyPtr( pLast, i ),
                 hb_ntxGetKeyPtr( pFirst, pFirst->uiKeys ), uiLen );
      }
      pLast->uiKeys -= iMove;
      pFirst->uiKeys--;
      hb_ntxSetKeyRec( pBasePage, uiPos, hb_ntxGetKeyRec( pFirst, pFirst->uiKeys ) );
      memcpy( hb_ntxGetKeyVal( pBasePage, uiPos ),
              hb_ntxGetKeyVal( pFirst, pFirst->uiKeys ), pTag->KeyLength );
   }
   pFirst->Changed = pLast->Changed = pBasePage->Changed = TRUE;
#ifdef HB_NTX_DEBUG
   hb_ntxPageCheckKeys( pBasePage, pTag, uiPos, 21 );
   hb_ntxPageCheckKeys( pFirst, pTag, iMove, 22 );
   hb_ntxPageCheckKeys( pLast, pTag, iMove, 23 );
#endif
}

/*
 * add key to the index at the curret page path
 */
static BOOL hb_ntxTagKeyAdd( LPTAGINFO pTag, LPKEYINFO pKey )
{
   int iLevel, iKey;
   LPPAGEINFO pPage = NULL;
   LPKEYINFO pNewKey = NULL;
   ULONG ulPage;
   BOOL fFound, fBottom = FALSE;

   if( pTag->UniqueKey )
   {
      ULONG ulRecNo = pKey->Xtra;

      pKey->Xtra = NTX_IGNORE_REC_NUM;
      fFound = hb_ntxTagKeyFind( pTag, pKey, pTag->KeyLength );
      pKey->Xtra = ulRecNo;
      if( fFound )
         return FALSE;
      fBottom = TRUE;
   }
   else
   {
      pKey->Tag = NTX_MAX_REC_NUM;
      fFound = hb_ntxTagKeyFind( pTag, pKey, pTag->KeyLength );
      pKey->Tag = 0;
      if( fFound )
      {
         if( pTag->MultiKey )
            fBottom = TRUE;
         else
            return FALSE;
      }
   }
   pTag->CurKeyInfo = hb_ntxKeyCopy( pTag->CurKeyInfo, pKey, pTag->KeyLength );

   iLevel = pTag->stackLevel - 1;
   if( fBottom )
   {
      pPage = hb_ntxPageLoad( pTag, pTag->stack[ iLevel ].page );
      if( ! pPage )
         return FALSE;
      ulPage = hb_ntxGetKeyPage( pPage, pTag->stack[ iLevel ].ikey );
      if( ulPage )
      {
         hb_ntxPageRelease( pTag, pPage );
         pPage = hb_ntxPageBottomMove( pTag, ulPage );
         if( ! pPage )
            return FALSE;
         iLevel = pTag->stackLevel - 1;
         if( pTag->stack[ iLevel ].ikey < pPage->uiKeys )
            pTag->stack[ iLevel ].ikey++;
      }
   }

   while( iLevel >= 0 && pKey )
   {
      if( pPage )
         hb_ntxPageRelease( pTag, pPage );
      pPage = hb_ntxPageLoad( pTag, pTag->stack[ iLevel ].page );
      if( ! pPage )
      {
         if( pNewKey )
            hb_ntxKeyFree( pNewKey );
         pTag->stackLevel = 0;
         return FALSE;
      }
      iKey = pTag->stack[ iLevel ].ikey;
      if( pPage->uiKeys < pTag->MaxKeys )
      {
         hb_ntxPageKeyAdd( pTag, pPage, iKey, pKey->Tag, pKey->Xtra, pKey->key );
         pKey = NULL;
      }
      else
      {
         pTag->stackLevel = 0;
#if defined( HB_NTX_STRONG_BALANCE )
         if( iLevel > 0 )
         {
            LPPAGEINFO pBasePage;
            USHORT uiFirst, uiLast, uiBaseKey;
            pBasePage = hb_ntxPageLoad( pTag, pTag->stack[ iLevel - 1 ].page );
            if( !pBasePage )
            {
               hb_ntxPageRelease( pTag, pPage );
               if( pNewKey )
                  hb_ntxKeyFree( pNewKey );
               return FALSE;
            }
            uiFirst = uiLast = uiBaseKey = pTag->stack[ iLevel -1 ].ikey;
            if( uiLast < pBasePage->uiKeys && hb_ntxGetKeyPage( pBasePage, uiLast + 1 ) != 0 )
               uiLast++;
            else if( uiFirst > 0 && hb_ntxGetKeyPage( pBasePage, uiFirst - 1 ) != 0 )
               uiFirst--;
            if( uiFirst != uiLast )
            {
               LPPAGEINFO pFirst, pLast;

               if( uiFirst == uiBaseKey )
               {
                  pFirst = pPage;
                  pLast = hb_ntxPageLoad( pTag, hb_ntxGetKeyPage( pBasePage, uiLast ) );
                  if( ! pLast )
                  {
                     hb_ntxPageRelease( pTag, pPage );
                     hb_ntxPageRelease( pTag, pBasePage );
                     if( pNewKey )
                        hb_ntxKeyFree( pNewKey );
                     return FALSE;
                  }
                  uiBaseKey = iKey;
               }
               else
               {
                  pLast = pPage;
                  pFirst = hb_ntxPageLoad( pTag, hb_ntxGetKeyPage( pBasePage, uiFirst ) );
                  if( ! pFirst )
                  {
                     hb_ntxPageRelease( pTag, pPage );
                     hb_ntxPageRelease( pTag, pBasePage );
                     if( pNewKey )
                        hb_ntxKeyFree( pNewKey );
                     return FALSE;
                  }
                  uiBaseKey = pFirst->uiKeys + iKey + 1;
               }
               if( pFirst->uiKeys + pLast->uiKeys <= ( pTag->MaxKeys - 1 ) << 1 )
               {
                  hb_ntxBalancePages( pTag, pBasePage, uiFirst, pFirst, pLast );
                  if( pFirst->uiKeys >= uiBaseKey )
                     hb_ntxPageKeyAdd( pTag, pFirst, uiBaseKey, pKey->Tag, pKey->Xtra, pKey->key );
                  else
                     hb_ntxPageKeyAdd( pTag, pLast, uiBaseKey - pFirst->uiKeys - 1, pKey->Tag, pKey->Xtra, pKey->key );
                  pKey = NULL;
               }
               if( pFirst != pPage )
                  hb_ntxPageRelease( pTag, pFirst );
               else
                  hb_ntxPageRelease( pTag, pLast );
               hb_ntxPageRelease( pTag, pBasePage );
               if( !pKey )
                  break;
            }
         }
#endif
         pKey = hb_ntxPageSplit( pTag, pPage, pKey, iKey );
         if( pNewKey )
            hb_ntxKeyFree( pNewKey );
         pNewKey = pKey;
      }
      iLevel--;
   }
   hb_ntxPageRelease( pTag, pPage );
   if( pKey )
   {
      pPage = hb_ntxPageNew( pTag, FALSE );
      if( ! pPage )
         return FALSE;
      hb_ntxPageKeyAdd( pTag, pPage, 0, pKey->Tag, pKey->Xtra, pKey->key );
      hb_ntxSetKeyPage( pPage, 1, pTag->RootBlock );
      pTag->RootBlock = pPage->Page;
      pTag->HdrChanged = TRUE;
      hb_ntxPageRelease( pTag, pPage );
      pTag->stackLevel = 0;
   }
   if( pNewKey )
      hb_ntxKeyFree( pNewKey );
   return TRUE;
}

/*
 * del key at the curret page path from the index
 */
static BOOL hb_ntxTagKeyDel( LPTAGINFO pTag, LPKEYINFO pKey )
{
   int iLevel, iBaseKey, iKey;
   LPPAGEINFO pBasePage, pPage;
   ULONG ulPage;

   pKey->Tag = 0;
   if( pTag->stackLevel == 0 || pTag->CurKeyInfo->Xtra != pKey->Xtra ||
       memcmp( pTag->CurKeyInfo->key, pKey->key, pTag->KeyLength ) != 0 )
   {
      if( ! hb_ntxTagKeyFind( pTag, pKey, pTag->KeyLength ) )
         return FALSE;
   }

   iLevel = pTag->stackLevel - 1;

   pPage = hb_ntxPageLoad( pTag, pTag->stack[ iLevel ].page );
   if( ! pPage )
      return FALSE;
   iKey = pTag->stack[ iLevel ].ikey;
   ulPage = hb_ntxGetKeyPage( pPage, iKey );

   if( ulPage )
   {
      pBasePage = pPage;
      iBaseKey = iKey;
      pPage = hb_ntxPageBottomMove( pTag, ulPage );
      if( ! pPage )
      {
         hb_ntxPageRelease( pTag, pBasePage );
         return FALSE;
      }
      iLevel = pTag->stackLevel - 1;
      iKey = pTag->stack[ iLevel ].ikey;

      hb_ntxSetKeyRec( pBasePage, iBaseKey, hb_ntxGetKeyRec( pPage, iKey ) );
      memcpy( hb_ntxGetKeyVal( pBasePage, iBaseKey ),
              hb_ntxGetKeyVal( pPage, iKey ), pTag->KeyLength );
      pBasePage->Changed = TRUE;
#ifdef HB_NTX_DEBUG
      hb_ntxPageCheckKeys( pBasePage, pTag, iBaseKey, 61 );
#endif
      hb_ntxPageRelease( pTag, pBasePage );
   }
   hb_ntxPageKeyDel( pPage, iKey );

   while( iLevel > 0 )
   {
      if( pPage->uiKeys < ( pTag->MaxKeys >> 1 ) )
      {
         USHORT uiFirst, uiLast, uiBaseKey;

         pBasePage = hb_ntxPageLoad( pTag, pTag->stack[ iLevel -1 ].page );
         if( ! pBasePage )
         {
            hb_ntxPageRelease( pTag, pPage );
            return FALSE;
         }
         uiFirst = uiLast = uiBaseKey = pTag->stack[ iLevel -1 ].ikey;
         if( uiLast < pBasePage->uiKeys && hb_ntxGetKeyPage( pBasePage, uiLast + 1 ) != 0 )
            uiLast++;
         else if( uiFirst > 0 && hb_ntxGetKeyPage( pBasePage, uiFirst - 1 ) != 0 )
            uiFirst--;

         if( uiFirst == uiLast )
         {
            if( pPage->uiKeys == 0 )
            {
               hb_ntxSetKeyPage( pBasePage, uiBaseKey, 0 );
               hb_ntxPageFree( pTag, pPage );
            }
            hb_ntxPageRelease( pTag, pPage );
         }
         else
         {
            LPPAGEINFO pFirst, pLast;

            if( uiFirst == uiBaseKey )
            {
               pFirst = pPage;
               pLast = hb_ntxPageLoad( pTag, hb_ntxGetKeyPage( pBasePage, uiLast ) );
               if( ! pLast )
               {
                  hb_ntxPageRelease( pTag, pPage );
                  hb_ntxPageRelease( pTag, pBasePage );
                  pTag->stackLevel = 0;
                  return FALSE;
               }
            }
            else
            {
               pLast = pPage;
               pFirst = hb_ntxPageLoad( pTag, hb_ntxGetKeyPage( pBasePage, uiFirst ) );
               if( ! pFirst )
               {
                  hb_ntxPageRelease( pTag, pPage );
                  hb_ntxPageRelease( pTag, pBasePage );
                  pTag->stackLevel = 0;
                  return FALSE;
               }
            }
            if( pFirst->uiKeys + pLast->uiKeys < pTag->MaxKeys )
               hb_ntxPageJoin( pTag, pBasePage, uiFirst, pFirst, pLast );
            else
               hb_ntxBalancePages( pTag, pBasePage, uiFirst, pFirst, pLast );
            hb_ntxPageRelease( pTag, pFirst );
            hb_ntxPageRelease( pTag, pLast );
         }
         pPage = pBasePage;
      }
      else
         break;
      iLevel--;
   }

   if( pPage->uiKeys == 0 && pPage->Page == pTag->RootBlock )
   {
      ulPage = hb_ntxGetKeyPage( pPage, 0 );
      if( ulPage != 0 )
      {
         pTag->RootBlock = ulPage;
         pTag->HdrChanged = TRUE;
         hb_ntxPageFree( pTag, pPage );
      }
   }
   hb_ntxPageRelease( pTag, pPage );
   pTag->stackLevel = 0;
   return TRUE;
}

/*
 * refresh CurKey value and set proper path from RootPage to LeafPage
 */
static BOOL hb_ntxCurKeyRefresh( LPTAGINFO pTag )
{
   NTXAREAP pArea = pTag->Owner->Owner;

   if( pArea->lpdbPendingRel )
      SELF_FORCEREL( ( AREAP ) pArea );

   if( !pArea->fPositioned )
   {
      pTag->stackLevel = 0;
      pTag->TagEOF = TRUE;
      pTag->CurKeyInfo->Xtra = 0;
      return FALSE;
   }
   else if( pTag->stackLevel == 0 || pTag->CurKeyInfo->Xtra != pArea->ulRecNo )
   {
      BYTE buf[ NTX_MAX_KEY ];
      BOOL fBuf = FALSE;
      LPKEYINFO pKey = NULL;
      /* Try to find previous if it's key for the same record */
      if( pTag->CurKeyInfo->Xtra == pArea->ulRecNo )
      {
         fBuf = TRUE;
         memcpy( buf, pTag->CurKeyInfo->key, pTag->KeyLength );
         pKey = hb_ntxKeyCopy( pKey, pTag->CurKeyInfo, pTag->KeyLength );
         hb_ntxTagKeyFind( pTag, pKey, pTag->KeyLength );
      }
      if( pTag->CurKeyInfo->Xtra != pArea->ulRecNo )
      {
         BOOL fValidBuf = pArea->fValidBuffer;
         /* not found, create new key from DBF and if differs seek again */
         pKey = hb_ntxEvalKey( pKey, pTag );
         if( !fBuf || memcmp( buf, pKey->key, pTag->KeyLength ) != 0 )
         {
            hb_ntxTagKeyFind( pTag, pKey, pTag->KeyLength );
         }
         /* not found, if key was generated from DBF buffer then force to
          * update it, create the new key and if differs seek again */
         if( pTag->CurKeyInfo->Xtra != pArea->ulRecNo && fValidBuf )
         {
            SELF_GOTO( ( AREAP ) pArea, pArea->ulRecNo );
            memcpy( buf, pKey->key, pTag->KeyLength );
            pKey = hb_ntxEvalKey( pKey, pTag );
            if( memcmp( buf, pKey->key, pTag->KeyLength ) != 0 )
               hb_ntxTagKeyFind( pTag, pKey, pTag->KeyLength );
         }
      }
      hb_ntxKeyFree( pKey );
      return( pTag->CurKeyInfo->Xtra != 0 && pTag->CurKeyInfo->Xtra == pArea->ulRecNo );
   }
   return TRUE;
}

/*
 * Skip in tag respecting record filter only
 */
static void hb_ntxTagSkipFilter( LPTAGINFO pTag, BOOL fForward )
{
   BOOL fBack, fEof = fForward ? pTag->TagEOF : pTag->TagBOF;

   fBack = pTag->fUsrDescend == pTag->AscendKey ? fForward : !fForward;

   while( !fEof && !hb_ntxCheckRecordScope( pTag->Owner->Owner,
                                            pTag->CurKeyInfo->Xtra ) )
   {
      if( fBack )
         fEof = !hb_ntxTagPrevKey( pTag );
      else
         fEof = !hb_ntxTagNextKey( pTag );

      if( !fEof && !hb_ntxKeyInScope( pTag, pTag->CurKeyInfo ) )
      {
         fEof = TRUE;
      }
   }
   if( fEof )
   {
      if( fForward )
         pTag->TagEOF = TRUE;
      else
         pTag->TagBOF = TRUE;
   }
}

/*
 * go to the first visiable record in Tag
 */
static void hb_ntxTagGoTop( LPTAGINFO pTag )
{
   PHB_NTXSCOPE pScope = pTag->fUsrDescend ? &pTag->bottom : &pTag->top;

   if( pScope->scopeKeyLen )
      hb_ntxTagKeyFind( pTag, pScope->scopeKey, pScope->scopeKeyLen );
   else if( pTag->fUsrDescend == pTag->AscendKey )
      hb_ntxTagBottomKey( pTag );
   else
      hb_ntxTagTopKey( pTag );

   pTag->TagEOF = pTag->CurKeyInfo->Xtra == 0 ||
                  !hb_ntxKeyInScope( pTag, pTag->CurKeyInfo );

   if( ! pTag->TagEOF && pTag->Owner->Owner->dbfi.fFilter )
      hb_ntxTagSkipFilter( pTag, TRUE );

   pTag->TagBOF = pTag->TagEOF;
}

/*
 * go to the last visiable record in Tag
 */
static void hb_ntxTagGoBottom( LPTAGINFO pTag )
{
   PHB_NTXSCOPE pScope = pTag->fUsrDescend ? &pTag->top : &pTag->bottom;

   if( pScope->scopeKeyLen )
      hb_ntxTagKeyFind( pTag, pScope->scopeKey, pScope->scopeKeyLen );
   else if( pTag->fUsrDescend == pTag->AscendKey )
      hb_ntxTagTopKey( pTag );
   else
      hb_ntxTagBottomKey( pTag );

   pTag->TagBOF = pTag->CurKeyInfo->Xtra == 0 ||
                  !hb_ntxKeyInScope( pTag, pTag->CurKeyInfo );

   if( ! pTag->TagBOF && pTag->Owner->Owner->dbfi.fFilter )
      hb_ntxTagSkipFilter( pTag, FALSE );

   pTag->TagEOF = pTag->TagBOF;
}

/*
 * skip to Next Key in the Tag
 */
static void hb_ntxTagSkipNext( LPTAGINFO pTag )
{
   pTag->TagBOF = FALSE;

   if( pTag->stackLevel == 0 )
      pTag->TagEOF = TRUE;
   else if( ! hb_ntxInTopScope( pTag, pTag->CurKeyInfo->key ) )
      hb_ntxTagGoTop( pTag );
   else if( pTag->fUsrDescend == pTag->AscendKey )
      pTag->TagEOF = !hb_ntxTagPrevKey( pTag );
   else
      pTag->TagEOF = !hb_ntxTagNextKey( pTag );

   if( ! pTag->TagEOF && ! hb_ntxKeyInScope( pTag, pTag->CurKeyInfo ) )
      pTag->TagEOF = TRUE;

   if( ! pTag->TagEOF && pTag->Owner->Owner->dbfi.fFilter )
      hb_ntxTagSkipFilter( pTag, TRUE );
}

/*
 * skip to Previous Key in the Tag
 */
static void hb_ntxTagSkipPrev( LPTAGINFO pTag )
{
   pTag->TagEOF = FALSE;

   if( pTag->stackLevel == 0 )
      /* TODO?: check if this is NTX behavior,
         for sure CDX works in such way */
      hb_ntxTagGoBottom( pTag );
   else if( pTag->fUsrDescend == pTag->AscendKey )
      pTag->TagBOF = !hb_ntxTagNextKey( pTag );
   else
      pTag->TagBOF = !hb_ntxTagPrevKey( pTag );

   if( ! pTag->TagBOF && ! hb_ntxKeyInScope( pTag, pTag->CurKeyInfo ) )
      pTag->TagBOF = TRUE;

   if( ! pTag->TagBOF && pTag->Owner->Owner->dbfi.fFilter )
      hb_ntxTagSkipFilter( pTag, FALSE );
}

/*
 * count keys in the given page and all subpages
 */
static ULONG hb_ntxPageCountKeys( LPTAGINFO pTag, ULONG ulPage )
{
   LPPAGEINFO pPage = hb_ntxPageLoad( pTag, ulPage );
   ULONG ulKeys;
   USHORT u;

   if( ! pPage )
      return 0;

   ulKeys = pPage->uiKeys;
   for( u = 0; u <= pPage->uiKeys; u++ )
   {
      ulPage = hb_ntxGetKeyPage( pPage, u );
      if( ulPage )
         ulKeys += hb_ntxPageCountKeys( pTag, ulPage );
   }
   hb_ntxPageRelease( pTag, pPage );

   return ulKeys;
}

/*
 * count relative position of current location in page stack 
 */
static double hb_ntxTagCountRelKeyPos( LPTAGINFO pTag )
{
   int iLevel = pTag->stackLevel, iKeys;
   double dPos = 1.0;

   while( --iLevel >= 0 )
   {
      LPPAGEINFO pPage = hb_ntxPageLoad( pTag, pTag->stack[ iLevel ].page );
      if( ! pPage )
         break;
      iKeys = pPage->uiKeys;
      if( hb_ntxGetKeyPage( pPage, pPage->uiKeys ) )
         ++iKeys;
      else if( iLevel == pTag->stackLevel - 1 )
         dPos = 0.5;
      dPos = ( dPos + pTag->stack[ iLevel ].ikey ) / iKeys;
      hb_ntxPageRelease( pTag, pPage );
   }
   if( pTag->fUsrDescend == pTag->AscendKey )
      dPos = 1.0 - dPos;
   return dPos;
}

static void hb_ntxTagGoToRelKeyPos( LPTAGINFO pTag, double dPos )
{
   LPPAGEINFO pPage = NULL;
   ULONG ulPage = 0;
   int iKey, iKeys;

   if( pTag->fUsrDescend == pTag->AscendKey )
      dPos = 1.0 - dPos;

   pTag->stackLevel = 0;
   do
   {
      if( pPage )
         hb_ntxPageRelease( pTag, pPage );
      pPage = hb_ntxPageLoad( pTag, ulPage );
      if( ! pPage )
      {
         pTag->stackLevel = 0;
         return;
      }
      if( pPage->uiKeys == 0 )
         iKey = 0;
      else
      {
         iKeys = pPage->uiKeys;
         if( hb_ntxGetKeyPage( pPage, pPage->uiKeys ) )
            ++iKeys;
         iKey = ( int ) ( dPos * iKeys );
         if( iKey >= iKeys )
            iKey = iKeys - 1;
         dPos = dPos * iKeys - iKey;
         if( dPos <= 0.0 )
            dPos = 0.0;
         else if( dPos >= 1.0 )
            dPos = 1.0;
      }
      hb_ntxTagSetPageStack( pTag, pPage->Page, iKey );
      ulPage = hb_ntxGetKeyPage( pPage, iKey );
   } while( ulPage != 0 );

   hb_ntxPageGetKey( pPage, iKey, pTag->CurKeyInfo, pTag->KeyLength );
   hb_ntxPageRelease( pTag, pPage );

   if( dPos > 0.75 )
      hb_ntxTagNextKey( pTag );
   else if( dPos < 0.25 )
      hb_ntxTagPrevKey( pTag );
}

/*
 * free pages allocated by tag
 */
static BOOL hb_ntxTagPagesFree( LPTAGINFO pTag, ULONG ulPage )
{
   LPPAGEINFO pPage = hb_ntxPageLoad( pTag, ulPage );
   BOOL fOK = pPage != NULL;
   USHORT u;

   for( u = 0; fOK && u <= pPage->uiKeys; u++ )
   {
      ulPage = hb_ntxGetKeyPage( pPage, u );
      if( ulPage )
         fOK = hb_ntxTagPagesFree( pTag, ulPage );
   }

   if( fOK )
   {
      pPage->uiKeys = 0;
      hb_ntxPageFree( pTag, pPage );
      if( !pPage->pPrev )
         fOK = hb_ntxPageSave( pTag->Owner, pPage );
   }
   hb_ntxPageRelease( pTag, pPage );

   return fOK;
}

/*
 * free space allocated by tag
 */
static ERRCODE hb_ntxTagSpaceFree( LPTAGINFO pTag )
{
   if( hb_ntxTagHeaderCheck( pTag ) )
   {
      if( pTag->RootBlock )
      {
         if( ! hb_ntxTagPagesFree( pTag, pTag->RootBlock ) )
            return FAILURE;
      }
      hb_ntxPageAddFree( pTag, pTag->HeadBlock );
      hb_ntxIndexTagDel( pTag->Owner, pTag->TagName );
      pTag->Owner->Changed = TRUE;
   }
   hb_ntxTagDelete( pTag );
   return SUCCESS;
}

/*
 * create index file name
 */
static void hb_ntxCreateFName( NTXAREAP pArea, char * szBagName, BOOL * fProd,
                               char * szFileName, char * szTagName )
{
   PHB_FNAME pFileName;
   PHB_ITEM pExt = NULL;
   BOOL fName = szBagName && *szBagName;

   pFileName = hb_fsFNameSplit( fName ? szBagName : pArea->szDataFileName );

   if( szTagName )
   {
      if( pFileName->szName )
         hb_strncpyUpperTrim( szTagName, pFileName->szName, NTX_MAX_TAGNAME );
      else
         szTagName[ 0 ] = '\0';
   }

   if( !pFileName->szExtension || !fName )
   {
      DBORDERINFO pExtInfo;
      memset( &pExtInfo, 0, sizeof( pExtInfo ) );
      pExt = pExtInfo.itmResult = hb_itemPutC( NULL, "" );
      if( SELF_ORDINFO( ( AREAP ) pArea, DBOI_BAGEXT, &pExtInfo ) == SUCCESS &&
          hb_itemGetCLen( pExt ) > 0 )
      {
         pFileName->szExtension = hb_itemGetCPtr( pExt );
      }
   }
   hb_fsFNameMerge( szFileName, pFileName );

   if( fProd )
   {
      if( ! pFileName->szName )
         *fProd = FALSE;
      else if( !fName )
         *fProd = TRUE;
      else
      {
         PHB_FNAME pTableFileName = hb_fsFNameSplit( pArea->szDataFileName );

         *fProd = pTableFileName->szName &&
                  hb_stricmp( pTableFileName->szName, pFileName->szName ) == 0;
         if( *fProd && pFileName->szExtension && ! pExt )
         {
            DBORDERINFO pExtInfo;
            memset( &pExtInfo, 0, sizeof( pExtInfo ) );
            pExt = pExtInfo.itmResult = hb_itemPutC( NULL, "" );
            if( SELF_ORDINFO( ( AREAP ) pArea, DBOI_BAGEXT, &pExtInfo ) == SUCCESS )
            {
               *fProd = hb_stricmp( pFileName->szExtension,
                                    hb_itemGetCPtr( pExt ) ) == 0;
            }
         }
         hb_xfree( pTableFileName );
      }
   }
   hb_xfree( pFileName );
   if( pExt )
      hb_itemRelease( pExt );
}

/*
 * find order bag by its name
 */
static LPNTXINDEX hb_ntxFindBag( NTXAREAP pArea, char * szBagName )
{
   LPNTXINDEX pIndex;
   PHB_FNAME pSeek, pName;
   BOOL fFound;

   pSeek = hb_fsFNameSplit( szBagName );
   if( ! pSeek->szName )
      pSeek->szName = "";

   pIndex = pArea->lpIndexes;
   while( pIndex )
   {
      pName = hb_fsFNameSplit( pIndex->IndexName );
      if( ! pName->szName )
         pName->szName = "";
      fFound = !hb_stricmp( pName->szName, pSeek->szName ) &&
               ( !pSeek->szPath || ( pName->szPath &&
                  !hb_stricmp( pName->szPath, pSeek->szPath ) ) ) &&
               ( !pSeek->szExtension || ( pName->szExtension &&
                  !hb_stricmp( pName->szExtension, pSeek->szExtension ) ) );
      hb_xfree( pName );
      if( fFound )
         break;
      pIndex = pIndex->pNext;
   }
   hb_xfree( pSeek );
   return pIndex;
}

/*
 * Find tag by name in index bag
 */
static int hb_ntxFindTagByName( LPNTXINDEX pIndex, char * szTag )
{
   int i;

   for( i = 0; i < pIndex->iTags; i++ )
   {
      if( !hb_strnicmp( pIndex->lpTags[ i ]->TagName, szTag,
                        NTX_MAX_TAGNAME ) )
         return i + 1;
   }
   return 0;
}

/*
 * Find the tag by its name or number
 */
static LPTAGINFO hb_ntxFindTag( NTXAREAP pArea, PHB_ITEM pTagItem,
                                PHB_ITEM pBagItem )
{
   LPNTXINDEX pIndex;
   BOOL fBag;

   if( ! pTagItem ||
       ( hb_itemType( pTagItem ) & ( HB_IT_STRING | HB_IT_NUMERIC ) ) == 0 )
      return pArea->lpCurTag;

   fBag = hb_itemGetCLen( pBagItem ) > 0;
   if( fBag )
   {
      if( hb_itemType( pTagItem ) & HB_IT_STRING )
         pIndex = hb_ntxFindBag( pArea, hb_itemGetCPtr( pBagItem ) );
      else
         pIndex = pArea->lpIndexes;
   }
   else
   {
      int iBag = hb_itemGetNI( pBagItem );

      pIndex = pArea->lpIndexes;
      if( iBag > 0 )
      {
         fBag = TRUE;
         while( pIndex )
         {
            if( --iBag == 0 )
               break;
            pIndex = pIndex->pNext;
         }
      }
      else if( iBag < 0 )
      {
         pIndex = NULL;
      }
   }
   if( pIndex )
   {
      if( hb_itemType( pTagItem ) & HB_IT_STRING )
      {
         char * szTag = hb_itemGetCPtr( pTagItem );
         int iTag;

         if( fBag )
            iTag = hb_ntxFindTagByName( pIndex, szTag );
         else
         {
            do
            {
               iTag = hb_ntxFindTagByName( pIndex, szTag );
               if( iTag )
                  break;
               pIndex = pIndex->pNext;
            } while( pIndex );
         }
         if( iTag )
            return pIndex->lpTags[ iTag - 1 ];
      }
      else
      {
         int i = hb_itemGetNI( pTagItem ) - 1;

         if( i >= 0 )
         {
            if( fBag )
            {
               if( i < pIndex->iTags )
                  return pIndex->lpTags[ i ];
            }
            else
            {
               do
               {
                  if( i < pIndex->iTags )
                     return pIndex->lpTags[ i ];
                  i -= pIndex->iTags;
                  pIndex = pIndex->pNext;
               } while( pIndex );
            }
         }
      }
   }

   return NULL;
}

/*
 * find the given tag number
 */
static int hb_ntxFindTagNum( NTXAREAP pArea, LPTAGINFO pTag )
{
   if( pArea->fSetTagNumbers )
   {
      LPNTXINDEX pIndex = pArea->lpIndexes;
      USHORT uiNum = 0, i;

      pTag->uiNumber = 0;
      while( pIndex )
      {
         for( i = 0; i < pIndex->iTags; i++ )
         {
            pIndex->lpTags[ i ]->uiNumber = ++uiNum;
         }
         pIndex = pIndex->pNext;
      }
      pArea->fSetTagNumbers = FALSE;
   }
   return pTag->uiNumber;
}

/*
 * count number of keys in given tag
 */
static ULONG hb_ntxOrdKeyCount( LPTAGINFO pTag )
{
   ULONG ulKeyCount = 0;

   if( !pTag->Owner->fShared && pTag->keyCount &&
       !pTag->Owner->Owner->dbfi.fFilter )
      return pTag->keyCount;

   if( hb_ntxTagLockRead( pTag ) )
   {
      hb_ntxTagRefreshScope( pTag );

      if( pTag->top.scopeKeyLen || pTag->bottom.scopeKeyLen ||
          pTag->Owner->Owner->dbfi.fFilter )
      {
         hb_ntxTagGoTop( pTag );
         while( !pTag->TagEOF )
         {
            ulKeyCount++;
            hb_ntxTagSkipNext( pTag );
         }
      }
      else
      {
         ulKeyCount = hb_ntxPageCountKeys( pTag, 0 );
      }
      if( !pTag->Owner->Owner->dbfi.fFilter )
         pTag->keyCount = ulKeyCount;
      hb_ntxTagUnLockRead( pTag );
   }
   return ulKeyCount;
}

/*
 * get the logical key position in the given tag
 */
static ULONG hb_ntxOrdKeyNo( LPTAGINFO pTag )
{
   ULONG ulKeyNo = 0;

   if( hb_ntxTagLockRead( pTag ) )
   {
      hb_ntxTagRefreshScope( pTag );
      if( hb_ntxCurKeyRefresh( pTag ) )
      {
         if( pTag->top.scopeKeyLen || pTag->bottom.scopeKeyLen ||
             pTag->Owner->Owner->dbfi.fFilter )
         {
            if( hb_ntxKeyInScope( pTag, pTag->CurKeyInfo ) )
            {
               do
               {
                  ulKeyNo++;
                  hb_ntxTagSkipPrev( pTag );
               }
               while( !pTag->TagBOF );
            }
         }
         else
         {
            int iLevel = pTag->stackLevel, iKey, iFirst = 1;
            BOOL fBack = pTag->fUsrDescend == pTag->AscendKey;
            LPPAGEINFO pPage;
            ULONG ulPage;

            while( --iLevel >= 0 )
            {
               pPage = hb_ntxPageLoad( pTag, pTag->stack[ iLevel ].page );
               if( ! pPage )
                  break;
               if( fBack )
               {
                  iKey = pTag->stack[ iLevel ].ikey;
                  ulKeyNo += pPage->uiKeys - iKey;
                  while( ++iKey <= pPage->uiKeys )
                  {
                     ulPage = hb_ntxGetKeyPage( pPage, iKey );
                     if( ulPage )
                        ulKeyNo += hb_ntxPageCountKeys( pTag, ulPage );
                  }
               }
               else
               {
                  ulKeyNo += iKey = pTag->stack[ iLevel ].ikey + iFirst;
                  iFirst = 0;
                  while( --iKey >= 0 )
                  {
                     ulPage = hb_ntxGetKeyPage( pPage, iKey );
                     if( ulPage )
                        ulKeyNo += hb_ntxPageCountKeys( pTag, ulPage );
                  }
               }
               hb_ntxPageRelease( pTag, pPage );
            }
         }
      }
      hb_ntxTagUnLockRead( pTag );
   }
   return ulKeyNo;
}

/*
 * set logical key position in given tag
 */
static BOOL hb_ntxOrdKeyGoto( LPTAGINFO pTag, ULONG ulKeyNo )
{
   if( ! ulKeyNo || ! hb_ntxTagLockRead( pTag ) )
      return FALSE;
   hb_ntxTagRefreshScope( pTag );
   hb_ntxTagGoTop( pTag );
   while( !pTag->TagEOF && --ulKeyNo )
   {
      hb_ntxTagSkipNext( pTag );
   }
   hb_ntxTagUnLockRead( pTag );
   return TRUE;
}

/*
 * get the relative key position (from 0.0 to 1.0) in the given tag
 */
static double hb_ntxOrdGetRelKeyPos( LPTAGINFO pTag )
{
   double dPos = 0.0, dStart = 0.0, dStop = 1.0, dFact = 0.0000000000001;
   BOOL fOK = TRUE, fFilter = pTag->Owner->Owner->dbfi.fFilter;

   if( ! hb_ntxTagLockRead( pTag ) )
      return FALSE;

   hb_ntxTagRefreshScope( pTag );

   pTag->Owner->Owner->dbfi.fFilter = FALSE;
   if( pTag->fUsrDescend ? pTag->bottom.scopeKeyLen : pTag->top.scopeKeyLen )
   {
      hb_ntxTagGoTop( pTag );
      if( pTag->TagEOF )
         fOK = FALSE;
      else
         dStart = hb_ntxTagCountRelKeyPos( pTag );
   }
   if( fOK && ( pTag->fUsrDescend ? pTag->top.scopeKeyLen : pTag->bottom.scopeKeyLen ) )
   {
      hb_ntxTagGoBottom( pTag );
      if( pTag->TagBOF )
         fOK = FALSE;
      else
         dStop = hb_ntxTagCountRelKeyPos( pTag );
   }
   pTag->Owner->Owner->dbfi.fFilter = fFilter;

   if( fOK )
   {
      if( hb_ntxCurKeyRefresh( pTag ) &&
          hb_ntxKeyInScope( pTag, pTag->CurKeyInfo ) )
      {
         if( dStart >= dStop - dFact )
            dPos = 0.5;
         else
         {
            dPos = hb_ntxTagCountRelKeyPos( pTag );
            dPos = ( dPos - dStart ) / ( dStop - dStart );
            /* fix possible differences in FL representation */
            if( dPos <= 0.0 )
               dPos = 0.0;
            else if( dPos >= 1.0 )
               dPos = 1.0;
         }
      }
   }
   hb_ntxTagUnLockRead( pTag );

   return dPos;
}

/*
 * set the relative key position (from 0.0 to 1.0) in the given tag
 */
static void hb_ntxOrdSetRelKeyPos( LPTAGINFO pTag, double dPos )
{
   if( hb_ntxTagLockRead( pTag ) )
   {
      NTXAREAP pArea = pTag->Owner->Owner;
      double dStart = 0.0, dStop = 1.0, dFact = 0.0000000000001;
      BOOL fOK = TRUE, fFilter = pArea->dbfi.fFilter;
      BOOL fForward = TRUE, fTop = FALSE;

      hb_ntxTagRefreshScope( pTag );

      if( dPos >= 1.0 )
         fForward = FALSE;
      else if( dPos <= 0.0 )
         fTop = TRUE;
      else
      {
         pArea->dbfi.fFilter = FALSE;
         if( pTag->fUsrDescend ? pTag->bottom.scopeKeyLen : pTag->top.scopeKeyLen )
         {
            hb_ntxTagGoTop( pTag );
            if( pTag->TagEOF )
               fOK = FALSE;
            else
               dStart = hb_ntxTagCountRelKeyPos( pTag );
         }
         if( fOK && ( pTag->fUsrDescend ? pTag->top.scopeKeyLen : pTag->bottom.scopeKeyLen ) )
         {
            hb_ntxTagGoBottom( pTag );
            if( pTag->TagBOF )
               fOK = FALSE;
            else
               dStop = hb_ntxTagCountRelKeyPos( pTag );
         }
         pArea->dbfi.fFilter = fFilter;

         if( fOK )
         {
            if( dStart >= dStop - dFact )
            {
               fTop = TRUE;
            }
            else
            {
               dPos = dPos * ( dStop - dStart ) + dStart;
               hb_ntxTagGoToRelKeyPos( pTag, dPos );
               if( pTag->CurKeyInfo->Xtra == 0 )
                  fForward = FALSE;
               else if( !hb_ntxInTopScope( pTag, pTag->CurKeyInfo->key ) )
                  fTop = TRUE;
               else if( !hb_ntxInBottomScope( pTag, pTag->CurKeyInfo->key ) )
                  fForward = FALSE;
            }
         }
      }
      if( !fOK )
      {
         SELF_GOTO( ( AREAP ) pArea, 0 );
      }
      else
      {
         LPTAGINFO pSavedTag = pArea->lpCurTag;
         pArea->lpCurTag = pTag;

         pArea->fTop = pArea->fBottom = FALSE;

         if( fForward )
         {
            if( fTop )
               hb_ntxTagGoTop( pTag );
            if( pTag->CurKeyInfo->Xtra != 0 )
            {
               SELF_GOTO( ( AREAP ) pArea, pTag->CurKeyInfo->Xtra );
               SELF_SKIPFILTER( ( AREAP ) pArea, 1 );
               if( pArea->fEof && !fTop )
                  fForward = FALSE;
            }
            else if( fTop )
               SELF_GOTO( ( AREAP ) pArea, 0 );
            else
               fForward = FALSE;
         }
         if( !fForward )
         {
            hb_ntxTagGoBottom( pTag );
            SELF_GOTO( ( AREAP ) pArea, pTag->CurKeyInfo->Xtra );
            if( pTag->CurKeyInfo->Xtra != 0 )
            {
               pArea->fBottom = TRUE;
               SELF_SKIPFILTER( ( AREAP ) pArea, -1 );
            }
         }
         pArea->lpCurTag = pSavedTag;
      }
      hb_ntxTagUnLockRead( pTag );
   }
}

/*
 * skip to next/previous unique key
 */
static BOOL hb_ntxOrdSkipUnique( LPTAGINFO pTag, LONG lDir )
{
   NTXAREAP pArea = pTag->Owner->Owner;
   BOOL fOut = FALSE, fEof = FALSE, fForward = ( lDir >= 0 );

   if( pArea->lpdbPendingRel )
      SELF_FORCEREL( ( AREAP ) pArea );

   pArea->fTop = pArea->fBottom = FALSE;

   if( hb_ntxTagLockRead( pTag ) )
   {
      LPTAGINFO pSavedTag = pArea->lpCurTag;
      pArea->lpCurTag = pTag;

      hb_ntxTagRefreshScope( pTag );
      if( hb_ntxCurKeyRefresh( pTag ) )
      {
         char keyVal[ NTX_MAX_KEY ];
         memcpy( keyVal, pTag->CurKeyInfo->key, pTag->KeyLength );

         do
         {
            if( fForward )
               hb_ntxTagSkipNext( pTag );
            else
               hb_ntxTagSkipPrev( pTag );
            fOut = pTag->TagEOF || pTag->TagBOF;
         }
         while( !fOut && hb_ntxValCompare( pTag,
                                       pTag->CurKeyInfo->key, pTag->KeyLength,
                                       keyVal, pTag->KeyLength, TRUE ) == 0 );
      }
      else if( !fForward && !pArea->fPositioned )
      {
         hb_ntxTagGoBottom( pTag );
         fEof = pTag->TagEOF;
      }
      else
      {
         fOut = TRUE;
      }
      if( fOut )
      {
         if( fForward )
            fEof = TRUE;
         else
         {
            hb_ntxTagGoTop( pTag );
            fEof = pTag->TagEOF;
         }
      }
      hb_ntxTagUnLockRead( pTag );

      SELF_GOTO( ( AREAP ) pArea, fEof ? 0 : pTag->CurKeyInfo->Xtra );
      if( !fEof )
      {
         SELF_SKIPFILTER( ( AREAP ) pArea, ( fForward || fOut ) ? 1 : -1 );
         if( ! fForward && fOut )
            pArea->fBof = TRUE;
      }

      /* Update Bof and Eof flags */
      if( fForward )
         pArea->fBof = FALSE;
      else
         pArea->fEof = FALSE;

      pArea->lpCurTag = pSavedTag;
      return TRUE;
   }
   return FALSE;
}

/*
 * skip while code block doesn't return TRUE
 */
static BOOL hb_ntxOrdSkipEval( LPTAGINFO pTag, BOOL fForward, PHB_ITEM pEval )
{
   NTXAREAP pArea = pTag->Owner->Owner;
   BOOL fFound = FALSE;

   HB_TRACE(HB_TR_DEBUG, ("hb_ntxOrdSkipEval(%p, %d, %p)", pTag, fForward, pEval));

   if( hb_itemType( pEval ) != HB_IT_BLOCK )
   {
      if( SELF_SKIP( ( AREAP ) pArea, fForward ? 1 : -1 ) != SUCCESS )
         return FALSE;
      return fForward ? !pArea->fEof : !pArea->fBof;
   }

   if( pArea->lpdbPendingRel )
      SELF_FORCEREL( ( AREAP ) pArea );

   pArea->fTop = pArea->fBottom = FALSE;

   if( hb_ntxTagLockRead( pTag ) )
   {
      LPTAGINFO pSavedTag = pArea->lpCurTag;
      pArea->lpCurTag = pTag;

      hb_ntxTagRefreshScope( pTag );
      if( hb_ntxCurKeyRefresh( pTag ) )
      {
         if( fForward )
            hb_ntxTagSkipNext( pTag );
         else
            hb_ntxTagSkipPrev( pTag );

         while( fForward ? !pTag->TagEOF : !pTag->TagBOF )
         {
            if( SELF_GOTO( ( AREAP ) pArea, pTag->CurKeyInfo->Xtra ) != SUCCESS )
               break;
            if( hb_ntxEvalSeekCond( pTag, pEval ) )
            {
               ULONG ulRecNo = pArea->ulRecNo;
               SELF_SKIPFILTER( ( AREAP ) pArea, fForward ? 1 : -1 );
               if( pArea->ulRecNo == ulRecNo || hb_ntxEvalSeekCond( pTag, pEval ) )
               {
                  fFound = TRUE;
                  break;
               }
            }
            if( fForward )
               hb_ntxTagSkipNext( pTag );
            else
               hb_ntxTagSkipPrev( pTag );
         }
         if( !fFound )
         {
            if( fForward )
               SELF_GOTO( ( AREAP ) pArea, 0 );
            else
            {
               SELF_GOTOP( ( AREAP ) pArea );
               pArea->fBof = TRUE;
            }
         }
      }
      pArea->lpCurTag = pSavedTag;
      hb_ntxTagUnLockRead( pTag );
   }

   /* Update Bof and Eof flags */
   if( fForward )
      pArea->fBof = FALSE;
   else
      pArea->fEof = FALSE;

   return fFound;
}

/*
 * skip while code block doesn't return TRUE
 */
static BOOL hb_ntxOrdSkipWild( LPTAGINFO pTag, BOOL fForward, PHB_ITEM pWildItm )
{
   NTXAREAP pArea = pTag->Owner->Owner;
   char *szPattern = hb_itemGetCPtr( pWildItm );
   BOOL fFound = FALSE;
   int iFixed = 0;

   HB_TRACE(HB_TR_DEBUG, ("hb_ntxOrdSkipWild(%p, %d, %p)", pTag, fForward, pWildItm));

   if( pTag->KeyType != 'C' || !szPattern || !*szPattern )
   {
      if( SELF_SKIP( ( AREAP ) pArea, fForward ? 1 : -1 ) != SUCCESS )
         return FALSE;
      return fForward ? !pArea->fEof : !pArea->fBof;
   }

#ifndef HB_CDP_SUPPORT_OFF
   if( pArea->cdPage != hb_cdp_page )
   {
      szPattern = hb_strdup( szPattern );
      hb_cdpTranslate( szPattern, hb_cdp_page, pArea->cdPage );
   }
#endif
   while( iFixed < pTag->KeyLength && szPattern[ iFixed ] &&
          szPattern[ iFixed ] != '*' && szPattern[ iFixed ] != '?' )
   {
      ++iFixed;
   }

   if( pArea->lpdbPendingRel )
      SELF_FORCEREL( ( AREAP ) pArea );

   pArea->fTop = pArea->fBottom = FALSE;

   if( hb_ntxTagLockRead( pTag ) )
   {
      LPTAGINFO pSavedTag = pArea->lpCurTag;
      pArea->lpCurTag = pTag;

      hb_ntxTagRefreshScope( pTag );
      if( hb_ntxCurKeyRefresh( pTag ) )
      {
         int iStop = fForward ? -1 : 1;
         if( pTag->fUsrDescend )
            iStop = -iStop;
         if( iFixed && hb_ntxValCompare( pTag, szPattern, iFixed,
                             pTag->CurKeyInfo->key, iFixed, FALSE ) == -iStop )
         {
            LPKEYINFO pKey;
            pKey = hb_ntxKeyNew( NULL, pTag->KeyLength );
            memcpy( pKey->key, szPattern, iFixed );
            pKey->key[ iFixed ] = '\0';
            pKey->Xtra = pArea->lpCurTag->fUsrDescend ==
                         pArea->lpCurTag->AscendKey ? NTX_MAX_REC_NUM :
                                                      NTX_IGNORE_REC_NUM;
            if( !hb_ntxTagKeyFind( pTag, pKey, iFixed ) )
            {
               if( fForward )
                  pTag->TagEOF = TRUE;
               else
                  pTag->TagBOF = TRUE;
            }
            hb_ntxKeyFree( pKey );
         }
         else if( fForward )
            hb_ntxTagSkipNext( pTag );
         else
            hb_ntxTagSkipPrev( pTag );

         while( fForward ? !pTag->TagEOF : !pTag->TagBOF )
         {
            if( hb_strMatchWild( pTag->CurKeyInfo->key, szPattern ) )
            {
               ULONG ulRecNo = pTag->CurKeyInfo->Xtra;
               if( SELF_GOTO( ( AREAP ) pArea, ulRecNo ) != SUCCESS )
                  break;
               SELF_SKIPFILTER( ( AREAP ) pArea, fForward ? 1 : -1 );
               if( pArea->ulRecNo == ulRecNo ||
                   hb_strMatchWild( pTag->CurKeyInfo->key, szPattern ) )
               {
                  fFound = TRUE;
                  break;
               }
            }
            if( iFixed && hb_ntxValCompare( pTag, szPattern, iFixed,
                             pTag->CurKeyInfo->key, iFixed, FALSE ) == iStop )
            {
               break;
            }
            if( fForward )
               hb_ntxTagSkipNext( pTag );
            else
               hb_ntxTagSkipPrev( pTag );
         }
         if( !fFound )
         {
            if( fForward )
               SELF_GOTO( ( AREAP ) pArea, 0 );
            else
            {
               SELF_GOTOP( ( AREAP ) pArea );
               pArea->fBof = TRUE;
            }
         }
      }
      pArea->lpCurTag = pSavedTag;
      hb_ntxTagUnLockRead( pTag );
   }

   /* Update Bof and Eof flags */
   if( fForward )
      pArea->fBof = FALSE;
   else
      pArea->fEof = FALSE;

#ifndef HB_CDP_SUPPORT_OFF
   if( pArea->cdPage != hb_cdp_page )
   {
      hb_xfree( szPattern );
   }
#endif

   return fFound;
}

#if defined(__XHARBOUR__)

static BOOL hb_ntxRegexMatch( LPTAGINFO pTag, PHB_REGEX pRegEx, char * szKey )
{
#ifndef HB_CDP_SUPPORT_OFF
   char szBuff[ NTX_MAX_KEY + 1 ];

   if( pTag->Owner->Owner->cdPage != hb_cdp_page )
   {
      hb_strncpy( szBuff, pTag->CurKeyInfo->key, pTag->KeyLength );
      hb_cdpnTranslate( szBuff, pTag->Owner->Owner->cdPage, hb_cdp_page, pTag->KeyLength );
      szKey = szBuff;
   }
#else
   HB_SYMBOL_UNUSED( pTag );
#endif
   return hb_regexMatch( pRegEx, szKey, FALSE );
}

/*
 * skip while regular expression on index key val doesn't return TRUE
 */
static BOOL hb_ntxOrdSkipRegEx( LPTAGINFO pTag, BOOL fForward, PHB_ITEM pRegExItm )
{
   NTXAREAP pArea = pTag->Owner->Owner;
   BOOL fFound = FALSE;
   HB_REGEX RegEx;

   HB_TRACE(HB_TR_DEBUG, ("hb_ntxOrdSkipRegEx(%p, %d, %p)", pTag, fForward, pRegExItm));

   if( pTag->KeyType != 'C' || !hb_regexGet( &RegEx, pRegExItm, 0, 0 ) )
   {
      if( SELF_SKIP( ( AREAP ) pArea, fForward ? 1 : -1 ) != SUCCESS )
         return FALSE;
      return fForward ? !pArea->fEof : !pArea->fBof;
   }

   if( pArea->lpdbPendingRel )
      SELF_FORCEREL( ( AREAP ) pArea );

   pArea->fTop = pArea->fBottom = FALSE;

   if( hb_ntxTagLockRead( pTag ) )
   {
      LPTAGINFO pSavedTag = pArea->lpCurTag;
      pArea->lpCurTag = pTag;

      hb_ntxTagRefreshScope( pTag );
      if( hb_ntxCurKeyRefresh( pTag ) )
      {
         if( fForward )
            hb_ntxTagSkipNext( pTag );
         else
            hb_ntxTagSkipPrev( pTag );

         while( fForward ? !pTag->TagEOF : !pTag->TagBOF )
         {
            if( SELF_GOTO( ( AREAP ) pArea, pTag->CurKeyInfo->Xtra ) != SUCCESS )
               break;

            if( hb_ntxRegexMatch( pTag, &RegEx, ( char * ) pTag->CurKeyInfo->key ) )
            {
               ULONG ulRecNo = pArea->ulRecNo;
               SELF_SKIPFILTER( ( AREAP ) pArea, fForward ? 1 : -1 );
               if( pArea->ulRecNo == ulRecNo ||
                   hb_ntxRegexMatch( pTag, &RegEx, ( char * ) pTag->CurKeyInfo->key ) )
               {
                  fFound = TRUE;
                  break;
               }
            }
            if( fForward )
               hb_ntxTagSkipNext( pTag );
            else
               hb_ntxTagSkipPrev( pTag );
         }
         if( !fFound )
         {
            if( fForward )
               SELF_GOTO( ( AREAP ) pArea, 0 );
            else
            {
               SELF_GOTOP( ( AREAP ) pArea );
               pArea->fBof = TRUE;
            }
         }
      }
      pArea->lpCurTag = pSavedTag;
      hb_ntxTagUnLockRead( pTag );
   }

   /* Update Bof and Eof flags */
   if( fForward )
      pArea->fBof = FALSE;
   else
      pArea->fEof = FALSE;

   hb_regexFree( &RegEx );

   return fFound;
}
#endif

/*
 * add key to custom tag (ordKeyAdd())
 * user key value is not implemented
 */
static BOOL hb_ntxOrdKeyAdd( LPTAGINFO pTag, PHB_ITEM pItem )
{
   NTXAREAP pArea = pTag->Owner->Owner;
   BOOL fResult = FALSE;
   LPKEYINFO pKey;

   if( pArea->lpdbPendingRel )
      SELF_FORCEREL( ( AREAP ) pArea );

   if( !pArea->fPositioned )
      return FALSE;

   if( pTag->pForItem && !hb_ntxEvalCond( pArea, pTag->pForItem, TRUE ) )
      return FALSE;

   if( pTag->Template && pItem && hb_itemType( pItem ) != HB_IT_NIL )
   {
      pKey = hb_ntxKeyPutItem( NULL, pItem, pArea->ulRecNo, pTag, TRUE, NULL );
   }
   else
   {
      pKey = hb_ntxEvalKey( NULL, pTag );
   }

   if( hb_ntxTagLockWrite( pTag ) )
   {
      if( hb_ntxTagKeyAdd( pTag, pKey ) )
      {
         fResult = TRUE;
         if( !pTag->Owner->fShared && pTag->keyCount &&
             hb_ntxKeyInScope( pTag, pKey ) )
            pTag->keyCount++;
      }
      hb_ntxTagUnLockWrite( pTag );
   }
   hb_ntxKeyFree( pKey );
   return fResult;
}

/*
 * del key from custom tag (ordKeyDel())
 * user key value is not implemented
 */
static BOOL hb_ntxOrdKeyDel( LPTAGINFO pTag, PHB_ITEM pItem )
{
   NTXAREAP pArea = pTag->Owner->Owner;
   BOOL fResult = FALSE;
   LPKEYINFO pKey;

   if( pArea->lpdbPendingRel )
      SELF_FORCEREL( ( AREAP ) pArea );

   if( !pArea->fPositioned )
      return FALSE;

   if( pTag->pForItem && !hb_ntxEvalCond( pArea, pTag->pForItem, TRUE ) )
      return FALSE;

   if( pTag->Template && pItem && hb_itemType( pItem ) != HB_IT_NIL )
   {
      pKey = hb_ntxKeyPutItem( NULL, pItem, pArea->ulRecNo, pTag, TRUE, NULL );
   }
   else
   {
      pKey = hb_ntxEvalKey( NULL, pTag );
   }

   if( hb_ntxTagLockWrite( pTag ) )
   {
      if( hb_ntxTagKeyDel( pTag, pKey ) )
      {
         fResult = TRUE;
         if( !pTag->Owner->fShared && pTag->keyCount &&
             hb_ntxKeyInScope( pTag, pKey ) )
            pTag->keyCount--;
      }
      hb_ntxTagUnLockWrite( pTag );
   }
   hb_ntxKeyFree( pKey );
   return fResult;
}

/*
 * DBOI_FINDREC find a specific record in the tag - it's useful for
 * custom indexes when the same record can be stored more then once
 * or when the used index key is unknown
 */
static BOOL hb_ntxOrdFindRec( LPTAGINFO pTag, ULONG ulRecNo, BOOL fCont )
{
   NTXAREAP pArea = pTag->Owner->Owner;
   BOOL fFound = FALSE;

   if( pTag && ulRecNo )
   {
      if( pArea->lpdbPendingRel && pArea->lpdbPendingRel->isScoped )
         SELF_FORCEREL( ( AREAP ) pArea );

      if( hb_ntxTagLockRead( pTag ) )
      {
         hb_ntxTagRefreshScope( pTag );
         if( fCont )
         {
            if( ! hb_ntxCurKeyRefresh( pTag ) )
               ulRecNo = 0;
            else
               hb_ntxTagSkipNext( pTag );
         }
         else
         {
            hb_ntxTagGoTop( pTag );
         }
         if( ulRecNo )
         {
            while( !pTag->TagEOF )
            {
               if( pTag->CurKeyInfo->Xtra == ulRecNo )
               {
                  fFound = TRUE;
                  break;
               }
               hb_ntxTagSkipNext( pTag );
            }
         }
         hb_ntxTagUnLockRead( pTag );
      }
   }
   SELF_GOTO( ( AREAP ) pArea, fFound ? ulRecNo : 0 );
   return fFound;
}

/*
 * evaluate given C function in given scope
 */
static ULONG hb_ntxOrdScopeEval( LPTAGINFO pTag,
                                 HB_EVALSCOPE_FUNC pFunc, void *pParam,
                                 PHB_ITEM pItemLo, PHB_ITEM pItemHi )
{
   ULONG ulCount = 0, ulLen = ( ULONG ) pTag->KeyLength;
   PHB_ITEM pItemTop = hb_itemNew( NULL ), pItemBottom = hb_itemNew( NULL );

   hb_ntxTagGetScope( pTag, 0, pItemTop );
   hb_ntxTagGetScope( pTag, 1, pItemBottom );
   hb_ntxTagSetScope( pTag, 0, pItemLo );
   hb_ntxTagSetScope( pTag, 1, pItemHi );

   if( hb_ntxTagLockRead( pTag ) )
   {
      hb_ntxTagGoTop( pTag );
      while( !pTag->TagEOF )
      {
         pFunc( pTag->CurKeyInfo->Xtra, (BYTE *) pTag->CurKeyInfo->key, ulLen, pParam );
         ulCount++;
         hb_ntxTagSkipNext( pTag );
      }
      hb_ntxTagUnLockRead( pTag );
   }

   hb_ntxTagSetScope( pTag, 0, pItemTop );
   hb_ntxTagSetScope( pTag, 1, pItemBottom );
   hb_itemRelease( pItemTop );
   hb_itemRelease( pItemBottom );

   return ulCount;
}

/* ************************************************************************* */
/* create index: hb_ntxTagCreate() */
/* ************************************************************************* */

static int hb_ntxQuickSortCompare( LPNTXSORTINFO pSort, BYTE * pKey1, BYTE * pKey2 )
{
   int iLen = pSort->keyLen, i;

   i = hb_ntxValCompare( pSort->pTag, (char *) pKey1, iLen, (char *) pKey2, iLen, TRUE );
   if( i == 0 )
   {
      if( pSort->pTag->fSortRec )
         i = ( HB_GET_LE_UINT32( pKey1 + iLen ) < HB_GET_LE_UINT32( pKey2 + iLen ) ) ? -1 : 1;
   }
   else if( ! pSort->pTag->AscendKey )
   {
      i = -i;
   }

   return i;
}

static BOOL hb_ntxQSort( LPNTXSORTINFO pSort, BYTE * pSrc, BYTE * pBuf, LONG lKeys )
{
   if( lKeys > 1 )
   {
      int iLen = pSort->keyLen + 4;
      LONG l1, l2;
      BYTE * pPtr1, * pPtr2, *pDst;
      BOOL f1, f2;

      l1 = lKeys >> 1;
      l2 = lKeys - l1;
      pPtr1 = &pSrc[ 0 ];
      pPtr2 = &pSrc[ l1 * iLen ];

      f1 = hb_ntxQSort( pSort, pPtr1, &pBuf[ 0 ], l1 );
      f2 = hb_ntxQSort( pSort, pPtr2, &pBuf[ l1 * iLen ], l2 );
      if( f1 )
      {
         pDst = pBuf;
      }
      else
      {
         pDst = pSrc;
         pPtr1 = &pBuf[ 0 ];
      }
      if( !f2 )
      {
         pPtr2 = &pBuf[ l1 * iLen ];
      }
      while( l1 > 0 && l2 > 0 )
      {
         if( hb_ntxQuickSortCompare( pSort, pPtr1, pPtr2 ) <= 0 )
         {
            memcpy( pDst, pPtr1, iLen );
            pPtr1 += iLen;
            l1--;
         }
         else
         {
            memcpy( pDst, pPtr2, iLen );
            pPtr2 += iLen;
            l2--;
         }
         pDst += iLen;
      }
      if( l1 > 0 )
      {
         memcpy( pDst, pPtr1, iLen * l1 );
      }
      else if( l2 > 0 && f1 == f2 )
      {
         memcpy( pDst, pPtr2, iLen * l2 );
      }
      return !f1;
   }
   return TRUE;
}

static void hb_ntxSortSortPage( LPNTXSORTINFO pSort )
{
   ULONG ulSize = pSort->ulKeys * ( pSort->keyLen + 4 );
   if( !hb_ntxQSort( pSort, pSort->pKeyPool, &pSort->pKeyPool[ ulSize ], pSort->ulKeys ) )
   {
      pSort->pStartKey = &pSort->pKeyPool[ ulSize ];
   }
   else
   {
      pSort->pStartKey = pSort->pKeyPool;
   }
}

static void hb_ntxSortBufferFlush( LPNTXSORTINFO pSort )
{
   ULONG ulSize;
   if( pSort->ulPagesIO )
   {
      LPNTXINDEX pIndex = pSort->pTag->Owner;
      hb_fsSeekLarge( pIndex->DiskFile,
                      hb_ntxFileOffset( pIndex, pSort->ulFirstIO ), FS_SET );
      ulSize = pSort->ulPagesIO * NTXBLOCKSIZE;
      if( hb_fsWriteLarge( pIndex->DiskFile, pSort->pBuffIO, ulSize ) != ulSize )
      {
         hb_ntxErrorRT( pIndex->Owner, EG_WRITE, EDBF_WRITE,
                        pIndex->IndexName, hb_fsError(), 0 );
      }
      pSort->ulPagesIO = 0;
      pIndex->fFlush = TRUE;
      if( pIndex->fShared )
         pIndex->Changed = TRUE;
   }
}

static void hb_ntxSortStorePage( LPNTXSORTINFO pSort, LPPAGEINFO pPage )
{
   LPNTXINDEX pIndex = pSort->pTag->Owner;
   if( !pPage->Page )
   {
      pPage->Page = hb_ntxPageAlloc( pIndex );
      if( pSort->ulSizeIO )
      {
         if( pSort->ulPagesIO == pSort->ulSizeIO )
            hb_ntxSortBufferFlush( pSort );
         if( !pSort->ulPagesIO ||
             hb_ntxFileOffset( pIndex, pSort->ulLastIO ) + NTXBLOCKSIZE ==
             hb_ntxFileOffset( pIndex, pPage->Page ) )
         {
            hb_ntxSetKeyCount( pPage, pPage->uiKeys );
            memcpy( pSort->pBuffIO + pSort->ulPagesIO * NTXBLOCKSIZE,
                    hb_ntxPageBuffer( pPage ), NTXBLOCKSIZE );
            pSort->ulLastIO = pPage->Page;
            if( !pSort->ulPagesIO++ )
               pSort->ulFirstIO = pPage->Page;
            pPage->Changed = FALSE;
            return;
         }
      }
   }
   if( !pPage->pPrev )
      hb_ntxPageSave( pIndex, pPage );
}

static void hb_ntxSortAddNodeKey( LPNTXSORTINFO pSort, BYTE *pKeyVal, ULONG ulRec )
{
   LPPAGEINFO pPage;
   ULONG ulPage = 0;
   int iLevel = 0;

   do
   {
      pPage = pSort->NodeList[ iLevel ];
      if( pPage == NULL )
      {
         pPage = pSort->NodeList[ iLevel ] = hb_ntxPageNew( pSort->pTag, TRUE );
         break;
      }
      else if( pPage->uiKeys >= pSort->pTag->MaxKeys )
      {
         hb_ntxSetKeyPage( pPage, pPage->uiKeys, ulPage );
         hb_ntxSortStorePage( pSort, pPage );
         ulPage = pPage->Page;
         hb_ntxPageRelease( pSort->pTag, pPage );
         pSort->NodeList[ iLevel++ ] = hb_ntxPageNew( pSort->pTag, TRUE );
      }
      else
         break;
   }
   while( TRUE );

   memcpy( hb_ntxGetKeyVal( pPage, pPage->uiKeys ), pKeyVal, pSort->pTag->KeyLength );
   hb_ntxSetKeyRec( pPage, pPage->uiKeys, ulRec );
   hb_ntxSetKeyPage( pPage, pPage->uiKeys, ulPage );
   pPage->uiKeys++;
}

static void hb_ntxSortWritePage( LPNTXSORTINFO pSort )
{
   ULONG ulSize = pSort->ulKeys * ( pSort->keyLen + 4 );

   hb_ntxSortSortPage( pSort );

   if( pSort->hTempFile == FS_ERROR )
   {
      BYTE szName[ _POSIX_PATH_MAX + 1 ];
      pSort->hTempFile = hb_fsCreateTemp( NULL, NULL, FC_NORMAL, szName );
      if( pSort->hTempFile == FS_ERROR )
      {
         hb_errInternal( 9999, "hb_ntxSortWritePage: Can't create temporary file.", "", "" );
      }
      pSort->szTempFileName = hb_strdup( ( char * ) szName );
   }
   pSort->pSwapPage[ pSort->ulCurPage ].ulKeys = pSort->ulKeys;
   pSort->pSwapPage[ pSort->ulCurPage ].nOffset = hb_fsSeekLarge( pSort->hTempFile, 0, FS_END );
   if( hb_fsWriteLarge( pSort->hTempFile, pSort->pStartKey, ulSize ) != ulSize )
   {
      hb_errInternal( 9999, "hb_ntxSortWritePage: Write error in temporary file.", "", "" );
   }
   pSort->ulKeys = 0;
   pSort->ulCurPage++;
}

static void hb_ntxSortGetPageKey( LPNTXSORTINFO pSort, ULONG ulPage,
                                  BYTE ** pKeyVal, ULONG *pulRec )
{
   int iLen = pSort->keyLen;

   if( pSort->pSwapPage[ ulPage ].ulKeyBuf == 0 )
   {
      ULONG ulKeys = HB_MIN( pSort->ulPgKeys, pSort->pSwapPage[ ulPage ].ulKeys );
      ULONG ulSize = ulKeys * ( iLen + 4 );

      if( hb_fsSeekLarge( pSort->hTempFile, pSort->pSwapPage[ ulPage ].nOffset, FS_SET ) != pSort->pSwapPage[ ulPage ].nOffset ||
          hb_fsReadLarge( pSort->hTempFile, pSort->pSwapPage[ ulPage ].pKeyPool, ulSize ) != ulSize )
      {
         hb_errInternal( 9999, "hb_ntxSortGetPageKey: Read error from temporary file.", "", "" );
      }
      pSort->pSwapPage[ ulPage ].nOffset += ulSize;
      pSort->pSwapPage[ ulPage ].ulKeyBuf = ulKeys;
      pSort->pSwapPage[ ulPage ].ulCurKey = 0;
   }
   *pKeyVal = &pSort->pSwapPage[ ulPage ].pKeyPool[ pSort->pSwapPage[ ulPage ].ulCurKey * ( iLen + 4 ) ];
   *pulRec = HB_GET_LE_UINT32( *pKeyVal + iLen );
}

static void hb_ntxSortOrderPages( LPNTXSORTINFO pSort )
{
   int iLen = pSort->keyLen, i;
   LONG l, r, m;
   ULONG n, ulPage, ulRec;
   BYTE *pKey = NULL, *pTmp;

   pSort->ulFirst = 0;
   pSort->pSortedPages = ( ULONG * ) hb_xgrab( pSort->ulPages * sizeof( ULONG ) );
   pSort->pSortedPages[ 0 ] = 0;

   if( pSort->ulTotKeys > 0 )
   {
      for( n = 0; n < pSort->ulPages; n++ )
      {
         hb_ntxSortGetPageKey( pSort, n, &pKey, &ulRec );
         l = 0;
         r = n - 1;
         while( l <= r )
         {
            m = ( l + r ) >> 1;
            ulPage = pSort->pSortedPages[ m ];
            pTmp = &pSort->pSwapPage[ ulPage ].pKeyPool[ pSort->pSwapPage[ ulPage ].ulCurKey * ( iLen + 4 ) ];
            i = hb_ntxValCompare( pSort->pTag, (char *) pKey, iLen, (char *) pTmp, iLen, TRUE );
            if( i == 0 )
            {
               if( pSort->pTag->fSortRec )
                  i = ( ulRec < HB_GET_LE_UINT32( &pTmp[ iLen ] ) ) ? -1 : 1;
            }
            else if( ! pSort->pTag->AscendKey )
               i = -i;
            if( i >= 0 )
               l = m + 1;
            else
               r = m - 1;
         }
         for( r = n; r > l; r-- )
            pSort->pSortedPages[ r ] = pSort->pSortedPages[ r - 1 ];
         pSort->pSortedPages[ l ] = n;
      }
   }
}

static BOOL hb_ntxSortKeyGet( LPNTXSORTINFO pSort, BYTE ** pKeyVal, ULONG *pulRec )
{
   int iLen = pSort->keyLen, i;
   LONG l, r, m;
   ULONG ulPage;

   ulPage = pSort->pSortedPages[ pSort->ulFirst ];

   /* check if first page has some keys yet */
   if( pSort->pSwapPage[ ulPage ].ulKeys > 0 )
   {
      BYTE *pKey, *pTmp;
      ULONG ulRec, ulPg;

      /*
       * last key was taken from this page - we have to resort it.
       * This is done intentionally here to be sure that the key
       * value return by this function will not be overwritten by
       * next keys in page read from temporary file in function
       * hb_ntxSortGetPageKey() - please do not move this part down
       * even it seems to be correct
       */
      hb_ntxSortGetPageKey( pSort, ulPage, &pKey, &ulRec );

      l = pSort->ulFirst + 1;
      r = pSort->ulPages - 1;
      while( l <= r )
      {
         m = ( l + r ) >> 1;
         ulPg = pSort->pSortedPages[ m ];
         pTmp = &pSort->pSwapPage[ ulPg ].pKeyPool[ pSort->pSwapPage[ ulPg ].ulCurKey * ( iLen + 4 ) ];
         i = hb_ntxValCompare( pSort->pTag, (char *) pKey, iLen, (char *) pTmp, iLen, TRUE );
         if( i == 0 )
         {
            if( pSort->pTag->fSortRec )
               i = ( ulRec < HB_GET_LE_UINT32( &pTmp[ iLen ] ) ) ? -1 : 1;
            else
               i = ( ulPage < ulPg ) ? -1 : 1;
         }
         else if( ! pSort->pTag->AscendKey )
            i = -i;
         if( i > 0 )
            l = m + 1;
         else
            r = m - 1;
      }
      if( l > ( LONG ) pSort->ulFirst + 1 )
      {
         ulPage = pSort->pSortedPages[ pSort->ulFirst ];
         for( r = pSort->ulFirst + 1; r < l; r++ )
            pSort->pSortedPages[ r - 1 ] = pSort->pSortedPages[ r ];
         pSort->pSortedPages[ l - 1 ] = ulPage;
      }
   }
   else
   {
      pSort->ulFirst++;
   }
   if( pSort->ulFirst < pSort->ulPages )
   {
      ulPage = pSort->pSortedPages[ pSort->ulFirst ];
      hb_ntxSortGetPageKey( pSort, ulPage, pKeyVal, pulRec );
      pSort->pSwapPage[ ulPage ].ulCurKey++;
      pSort->pSwapPage[ ulPage ].ulKeys--;
      pSort->pSwapPage[ ulPage ].ulKeyBuf--;
      return TRUE;
   }
   return FALSE;
}

static void hb_ntxSortKeyAdd( LPNTXSORTINFO pSort, ULONG ulRec, char * pKeyVal, int iKeyLen )
{
   int iLen = pSort->keyLen;
   BYTE *pDst;

   if( pSort->ulKeys >= pSort->ulPgKeys )
   {
      hb_ntxSortWritePage( pSort );
   }
   pDst = &pSort->pKeyPool[ pSort->ulKeys * ( iLen + 4 ) ];

   if( iLen > iKeyLen )
   {
      memcpy( pDst, pKeyVal, iKeyLen );
      memset( &pDst[ iKeyLen ], ' ', iLen - iKeyLen );
   }
   else
   {
      memcpy( pDst, pKeyVal, iLen );
   }
   HB_PUT_LE_UINT32( &pDst[ iLen ], ulRec );
   pSort->ulKeys++;
   pSort->ulTotKeys++;
}

static LPNTXSORTINFO hb_ntxSortNew( LPTAGINFO pTag, ULONG ulRecCount )
{
   LPNTXSORTINFO pSort;
   BYTE * pBuf;
   int iLen = pTag->KeyLength;
   ULONG ulSize, ulMax, ulMin;

   if( ulRecCount == 0 )
      ulRecCount = 1;

   pSort = ( LPNTXSORTINFO ) hb_xgrab( sizeof( NTXSORTINFO ) );
   memset( pSort, 0, sizeof( NTXSORTINFO ) );

   ulMin = ( ULONG ) ceil( sqrt( ( double ) ulRecCount ) );
   ulMax = ( ( ULONG ) ceil( sqrt( ( double ) ulRecCount / ( iLen + 4 ) ) ) ) << 7;
   /*
    * this effectively increase allocated memory buffer for very large files
    * moving the maximum to: 270'566'400 for 4'294'967'295 records and 256
    * index key length.
    * if you want to force smaller buffer I wrote below then add here:
    * ulMax = ulMin;
    */
   ulSize = ( 1L << 20 ) / ( iLen + 4 );
   while( ulMax < ulSize )
      ulMax <<= 1;
   if( ulMax > ulRecCount )
      ulMax = ulRecCount;

   do
   {
      ulSize = ulMax * ( iLen + 4 );
      pBuf = ( BYTE * ) hb_xalloc( ulSize << 2 );
      if( pBuf )
      {
         hb_xfree( pBuf );
         pBuf = ( BYTE * ) hb_xalloc( ulSize << 1 );
      }
      else
      {
         ulMax >>= 1;
      }
   }
   while( ! pBuf && ulMax >= ulMin );

   if( ! pBuf )
   {
      /* call hb_xgrab() to force out of memory error,
       * though in multi process environment this call may return
       * with success when other process free some memory
       * (also the size of buf is reduced to absolute minimum).
       * Sorry but I'm to lazy to implement indexing with smaller
       * memory though it's possible - just simply I can even create
       * index on-line by key adding like in normal update process.
       * The memory necessary to index file is now ~
       *    ~ (keySize+4+sizeof(NTXSWAPPAGE)) * sqrt(ulRecCount) * 2
       * so the maximum is for DBF with 2^32 records and keySize 256 ~
       * ~ 2^17 * 284 ~=~ 37 Mb
       * this is not a problem for current computers and I do not see
       * any way to use DBFs with four billions records and indexes with
       * such long (256 bytes) keys on the old ones - they will be simply
       * to slow. IMHO it's also better to signal out of memory here and
       * force some system upgrades then run process which will have to
       * take many hours, Druzus.
       */
      ulMax = ulMin;
      pBuf = ( BYTE * ) hb_xgrab( ( ulMax << 1 ) * ( iLen + 4 ) );
   }

   pSort->pTag = pTag;
   pSort->hTempFile = FS_ERROR;
   pSort->keyLen = iLen;
   pSort->fUnique = pTag->UniqueKey;
   pSort->ulMaxKey = ulMax << 1;
   pSort->ulPgKeys = ulMax;
   pSort->ulMaxRec = ulRecCount;
   pSort->pKeyPool = pBuf;
   pSort->ulPages = ( ulRecCount + pSort->ulPgKeys - 1 ) / pSort->ulPgKeys;
   /* check for overflow on 32 bit machines when number of records is nearly 2^32 */
   if( !pSort->ulPages )
      pSort->ulPages = ulRecCount / pSort->ulPgKeys + 1;
   pSort->pSwapPage = ( LPNTXSWAPPAGE ) hb_xgrab( sizeof( NTXSWAPPAGE ) * pSort->ulPages );
   memset( pSort->pSwapPage, 0, sizeof( NTXSWAPPAGE ) * pSort->ulPages );
   return pSort;
}

static void hb_ntxSortFree( LPNTXSORTINFO pSort, BOOL fFull )
{
   if( pSort->hTempFile != FS_ERROR )
   {
      hb_fsClose( pSort->hTempFile );
      pSort->hTempFile = FS_ERROR;
   }
   if( pSort->szTempFileName )
   {
      hb_fsDelete( ( BYTE * )  pSort->szTempFileName );
      hb_xfree( pSort->szTempFileName );
      pSort->szTempFileName = NULL;
   }
   if( pSort->pKeyPool )
   {
      hb_xfree( pSort->pKeyPool );
      pSort->pKeyPool = NULL;
   }
   if( pSort->pSwapPage )
   {
      hb_xfree( pSort->pSwapPage );
      pSort->pSwapPage = NULL;
   }
   if( pSort->pBuffIO )
   {
      hb_xfree( pSort->pBuffIO );
      pSort->pBuffIO = NULL;
   }
   if( pSort->pSortedPages )
   {
      hb_xfree( pSort->pSortedPages );
      pSort->pSortedPages = NULL;
   }
   if( fFull )
   {
      hb_xfree( pSort );
   }
}

static void hb_ntxSortOut( LPNTXSORTINFO pSort )
{
   BOOL fUnique = pSort->fUnique, fBalance, fNext;
   LPTAGINFO pTag = pSort->pTag;
   ULONG ulPage, ulRec, ulKey;
   USHORT uiHalf;
   BYTE * pKeyVal;
   int iLen = pSort->keyLen, iLevel;

   pSort->ulPages = pSort->ulCurPage + 1;
   pSort->ulPgKeys = pSort->ulMaxKey / pSort->ulPages;
   if( pSort->ulPages > 1 )
   {
      BYTE * pBuf = pSort->pKeyPool;
      hb_ntxSortWritePage( pSort );
      for( ulPage = 0; ulPage < pSort->ulPages; ulPage++ )
      {
         pSort->pSwapPage[ ulPage ].ulKeyBuf = 0;
         pSort->pSwapPage[ ulPage ].ulCurKey = 0;
         pSort->pSwapPage[ ulPage ].pKeyPool = pBuf;
         pBuf += pSort->ulPgKeys * ( pSort->keyLen + 4 );
      }
   }
   else
   {
      hb_ntxSortSortPage( pSort );
      pSort->pSwapPage[ 0 ].ulKeys = pSort->ulKeys;
      pSort->pSwapPage[ 0 ].ulKeyBuf = pSort->ulKeys;
      pSort->pSwapPage[ 0 ].ulCurKey = 0;
      pSort->pSwapPage[ 0 ].pKeyPool = pSort->pStartKey;
   }
   /* printf("pSort->ulPages=%ld, pSort->ulPgKeys=%ld", pSort->ulPages, pSort->ulPgKeys);fflush(stdout); */

   hb_ntxSortOrderPages( pSort );

   for( ulKey = 0; ulKey < pSort->ulTotKeys; ulKey++ )
   {
      if( ! hb_ntxSortKeyGet( pSort, &pKeyVal, &ulRec ) )
      {
         hb_errInternal( 9999, "hb_ntxSortOut: memory structure corrupted.", "", "" );
      }
      if( fUnique )
      {
         if( ulKey != 0 && hb_ntxValCompare( pTag, (char *) pSort->pLastKey, iLen, (char *) pKeyVal, iLen, TRUE ) == 0 )
         {
            continue;
         }
#ifndef HB_NTX_DEBUG_EXT
         else
         {
            memcpy( pSort->pLastKey, pKeyVal, iLen );
         }
#endif
      }
#ifdef HB_NTX_DEBUG_EXT
      if( ulKey != 0 )
      {
         int i = hb_ntxValCompare( pTag, (char *) pSort->pLastKey, iLen, (char *) pKeyVal, iLen, TRUE );
         if( ! pTag->AscendKey )
            i = -i;
         if( i == 0 )
            i = ( pSort->ulLastRec < ulRec ) ? -1 : 1;
         if( i > 0 )
         {
            printf("\r\nulKey=%ld, pKeyVal=[%s][%ld], pKeyLast=[%s][%ld]\r\n",
                   ulKey, pKeyVal, ulRec, pSort->pLastKey, pSort->ulLastRec); fflush(stdout);
            hb_errInternal( 9999, "hb_ntxSortOut: sorting fails.", "", "" );
         }
      }
      memcpy( pSort->pLastKey, pKeyVal, iLen );
      pSort->ulLastRec = ulRec;
#endif
      hb_ntxSortAddNodeKey( pSort, pKeyVal, ulRec );
   }

#ifdef HB_NTX_DEBUG
   if( hb_ntxSortKeyGet( pSort, &pKeyVal, &ulRec ) )
   {
      hb_errInternal( 9999, "hb_ntxSortOut: memory structure corrupted(2).", "", "" );
   }
#endif

   if( pSort->NodeList[ 0 ] == NULL )
   {
      pSort->NodeList[ 0 ] = hb_ntxPageNew( pTag, TRUE );
   }
   hb_ntxSetKeyPage( pSort->NodeList[ 0 ], pSort->NodeList[ 0 ]->uiKeys, 0 );

   iLevel = 0;
   fNext = TRUE;
   fBalance = FALSE;
   uiHalf = pTag->MaxKeys >> 1;
   do
   {
      hb_ntxSortStorePage( pSort, pSort->NodeList[ iLevel ] );
      if( iLevel + 1 == NTX_STACKSIZE || pSort->NodeList[ iLevel + 1 ] == NULL )
      {
         pTag->RootBlock = pSort->NodeList[ iLevel ]->Page;
         fNext = FALSE;
      }
      else
      {
         hb_ntxSetKeyPage( pSort->NodeList[ iLevel + 1 ],
                           pSort->NodeList[ iLevel + 1 ]->uiKeys,
                           pSort->NodeList[ iLevel ]->Page );
         if( pSort->NodeList[ iLevel ]->uiKeys < uiHalf )
         {
            fBalance = TRUE;
         }
      }
      hb_ntxPageRelease( pTag, pSort->NodeList[ iLevel ] );
      iLevel++;
   }
   while( fNext );

   hb_ntxSortBufferFlush( pSort );
   hb_ntxSortFree( pSort, FALSE );

   if( fBalance )
   {
      LPPAGEINFO pPage, pFirst, pLast;

      ulPage = pTag->RootBlock;
      while( ulPage )
      {
         pPage = hb_ntxPageLoad( pTag, ulPage );
         if( ! pPage )
            return;
         ulPage = hb_ntxGetKeyPage( pPage, pPage->uiKeys );
         if( ulPage && pPage->uiKeys )
         {
            pLast = hb_ntxPageLoad( pTag, ulPage );
            if( ! pLast )
            {
               hb_ntxPageRelease( pTag, pPage );
               return;
            }
            if( pLast->uiKeys < uiHalf )
            {
               pFirst = hb_ntxPageLoad( pTag, hb_ntxGetKeyPage( pPage,
                                                         pPage->uiKeys - 1 ) );
               if( ! pFirst )
               {
                  hb_ntxPageRelease( pTag, pPage );
                  hb_ntxPageRelease( pTag, pLast );
                  return;
               }
               hb_ntxBalancePages( pTag, pPage, pPage->uiKeys - 1, pFirst, pLast );
               hb_ntxPageRelease( pTag, pFirst );
            }
            hb_ntxPageRelease( pTag, pLast );
         }
         hb_ntxPageRelease( pTag, pPage );
      }
   }
}

/*
 * create tag in index file
 */
static ERRCODE hb_ntxTagCreate( LPTAGINFO pTag, BOOL fReindex )
{
   LPNTXAREA pArea = pTag->Owner->Owner;
   PHB_ITEM pForItem, pWhileItem = NULL, pEvalItem = NULL, pItem = NULL;
   ULONG ulRecCount, ulRecNo = pArea->ulRecNo;
   LPNTXSORTINFO pSort;
   LONG lStep = 0;
   ERRCODE errCode = SUCCESS;

   if( pArea->lpdbOrdCondInfo )
   {
      pWhileItem = pArea->lpdbOrdCondInfo->itmCobWhile;
      lStep = pArea->lpdbOrdCondInfo->lStep;
      pEvalItem = pArea->lpdbOrdCondInfo->itmCobEval;
   }

   if( pTag->Custom )
   {
      ulRecCount = 0;
   }
   else
   {
      errCode = SELF_RECCOUNT( ( AREAP ) pArea, &ulRecCount );
      if( errCode != SUCCESS )
         return errCode;
   }
   pArea->pSort = pSort = hb_ntxSortNew( pTag, ulRecCount );
   pSort->fReindex = fReindex;

   if( ulRecCount == 0 )
   {
      LPPAGEINFO pPage = hb_ntxPageNew( pTag, FALSE );

      if( pPage )
      {
         pTag->RootBlock = pPage->Page;
         hb_ntxPageRelease( pTag, pPage );
      }
      else
      {
         errCode = FAILURE;
      }
   }
   else
   {
      LPTAGINFO pSaveTag = pArea->lpCurTag;
      ULONG ulStartRec = 0, ulNextCount = 0;
      BOOL fDirectRead, fUseFilter = FALSE;
      BYTE * pSaveRecBuff = pArea->pRecord;
      char szBuffer[ NTX_MAX_KEY ];
      int iRecBuff = 0, iRecBufSize, iRec;
#ifndef HB_CDP_SUPPORT_OFF
      /* TODO%: this hack is not thread safe, hb_cdp_page has to be thread specific */
      PHB_CODEPAGE cdpTmp = hb_cdp_page;
      hb_cdp_page = pArea->cdPage;
#endif

      pForItem = pTag->pForItem;
      if( pTag->nField )
         pItem = hb_itemNew( NULL );

      if( !pArea->lpdbOrdCondInfo || pArea->lpdbOrdCondInfo->fAll )
      {
         pArea->lpCurTag = NULL;
      }
      else
      {
         if( pArea->lpdbOrdCondInfo->itmRecID )
            ulStartRec = hb_itemGetNL( pArea->lpdbOrdCondInfo->itmRecID );
         if ( ulStartRec )
         {
            ulNextCount = 1;
         }
         else if( pArea->lpdbOrdCondInfo->fRest || pArea->lpdbOrdCondInfo->lNextCount > 0 )
         {
            if( pArea->lpdbOrdCondInfo->itmStartRecID )
               ulStartRec = hb_itemGetNL( pArea->lpdbOrdCondInfo->itmStartRecID );
            if( !ulStartRec )
               ulStartRec = ulRecNo;
            if( pArea->lpdbOrdCondInfo->lNextCount > 0 )
               ulNextCount = pArea->lpdbOrdCondInfo->lNextCount;
         }
         else if( pArea->lpdbOrdCondInfo->fUseFilter )
         {
            fUseFilter = TRUE;
         }
         else if( !pArea->lpdbOrdCondInfo->fUseCurrent )
         {
            pArea->lpCurTag = NULL;
         }
      }

      fDirectRead = !hb_set.HB_SET_STRICTREAD && /* !pArea->lpdbRelations && */
                    ( !pArea->lpdbOrdCondInfo || pArea->lpdbOrdCondInfo->fAll ||
                      ( pArea->lpCurTag == NULL && !fUseFilter ) );

      pSort->ulSizeIO = ( 1 << 16 ) / NTXBLOCKSIZE;
      pSort->pBuffIO = (BYTE *) hb_xgrab( pSort->ulSizeIO * NTXBLOCKSIZE );
      iRecBufSize = ( pSort->ulSizeIO * NTXBLOCKSIZE ) / pArea->uiRecordLen;

      if( ulStartRec == 0 && pArea->lpCurTag == NULL )
         ulStartRec = 1;

      if( ulStartRec == 0 )
      {
         errCode = SELF_GOTOP( ( AREAP ) pArea );
      }
      else
      {
         errCode = SELF_GOTO( ( AREAP ) pArea, ulStartRec );
         if( fUseFilter && errCode == SUCCESS )
            errCode = SELF_SKIPFILTER( ( AREAP ) pArea, 1 );
      }

      ulRecNo = pArea->ulRecNo;

      if( ulNextCount && ulRecCount >= ulRecNo + ulNextCount )
         ulRecCount = ulRecNo + ulNextCount - 1;

      while( errCode == SUCCESS )
      {
         if( ulRecNo > ulRecCount )
            pArea->fEof = TRUE;

         if( pArea->fEof )
            break;

         if( fDirectRead )
         {
            if( iRecBuff == 0 || iRecBuff >= iRecBufSize )
            {
               if( ulRecCount - ulRecNo >= (ULONG) iRecBufSize )
                  iRec = iRecBufSize;
               else
                  iRec = ulRecCount - ulRecNo + 1;
               if( iRec <= 0 )
                  break;
               hb_fsSeekLarge( pArea->hDataFile,
                               ( HB_FOFFSET ) pArea->uiHeaderLen +
                               ( HB_FOFFSET ) ( ulRecNo - 1 ) *
                               ( HB_FOFFSET ) pArea->uiRecordLen, FS_SET );
               hb_fsReadLarge( pArea->hDataFile, pSort->pBuffIO, pArea->uiRecordLen * iRec );
               iRecBuff = 0;
            }
            pArea->pRecord = pSort->pBuffIO + iRecBuff * pArea->uiRecordLen;
            pArea->ulRecNo = ulRecNo;
            if( SELF_GETREC( ( AREAP ) pArea, NULL ) == FAILURE )
               break;
            pArea->fValidBuffer = pArea->fPositioned = TRUE;
            pArea->fDeleted = pArea->pRecord[ 0 ] == '*';
            /* Force relational movement in child WorkAreas */
            if( pArea->lpdbRelations )
            {
               errCode = SELF_SYNCCHILDREN( ( AREAP ) pArea );
               if( errCode != SUCCESS )
                  break;
            }
            iRecBuff++;
         }

         if( pWhileItem && !hb_ntxEvalCond( NULL, pWhileItem, FALSE ) )
            break;

         if( pForItem == NULL || hb_ntxEvalCond( pArea, pForItem, FALSE ) )
         {
            if( pTag->nField )
               errCode = SELF_GETVALUE( ( AREAP ) pArea, pTag->nField, pItem );
            else
               pItem = hb_vmEvalBlockOrMacro( pTag->pKeyItem );

            switch( hb_itemType( pItem ) )
            {
               case HB_IT_STRING:
               case HB_IT_STRING | HB_IT_MEMO:
                  hb_ntxSortKeyAdd( pSort, pArea->ulRecNo,
                                    hb_itemGetCPtr( pItem ),
                                    hb_itemGetCLen( pItem ) );
                  break;

               case HB_IT_INTEGER:
               case HB_IT_LONG:
               case HB_IT_DOUBLE:
                  hb_ntxNumToStr( pItem, szBuffer, pTag->KeyLength, pTag->KeyDec );
                  hb_ntxSortKeyAdd( pSort, pArea->ulRecNo, szBuffer, pTag->KeyLength );
                  break;

               case HB_IT_DATE:
                  hb_itemGetDS( pItem, szBuffer );
                  hb_ntxSortKeyAdd( pSort, pArea->ulRecNo, szBuffer, 8 );
                  break;

               case HB_IT_LOGICAL:
                  szBuffer[0] = hb_itemGetL( pItem ) ? 'T' : 'F';
                  hb_ntxSortKeyAdd( pSort, pArea->ulRecNo, szBuffer, 1 );
                  break;

               default:
                  hb_ntxErrorRT( pArea, EG_DATATYPE, EDBF_INVALIDKEY,
                                 pTag->Owner->IndexName, 0, 0 );
                  errCode = FAILURE;
                  pTag->Partial = TRUE;
                  pEvalItem = NULL;
                  ulNextCount = 1;
                  break;
            }
         }

         if( ulNextCount > 0 )
         {
            if( --ulNextCount == 0 )
               break;
         }

         if( pEvalItem )
         {
            if( lStep >= pArea->lpdbOrdCondInfo->lStep )
            {
               lStep = 0;
               if( !hb_ntxEvalCond( pArea, pEvalItem, FALSE ) )
               {
                  pTag->Partial = TRUE;
                  break;
               }
            }
            ++lStep;
         }

         if( fDirectRead )
            ulRecNo++;
         else if( errCode == SUCCESS )
         {
            errCode = SELF_SKIPRAW( ( AREAP ) pArea, 1 );
            if( fUseFilter && errCode == SUCCESS )
               errCode = SELF_SKIPFILTER( ( AREAP ) pArea, 1 );
            ulRecNo = pArea->ulRecNo;
         }
      }

      if( fDirectRead )
      {
         pArea->pRecord = pSaveRecBuff;
         pArea->fValidBuffer = FALSE;
         if( errCode == SUCCESS )
            errCode = SELF_GOTO( ( AREAP ) pArea, ulRecNo );
      }

      if( errCode == SUCCESS )
         hb_ntxSortOut( pSort );

      if( pTag->nField )
         hb_itemRelease( pItem );

      pArea->lpCurTag = pSaveTag;
#ifndef HB_CDP_SUPPORT_OFF
      hb_cdp_page = cdpTmp;
#endif
   }

   hb_ntxSortFree( pSort, TRUE );
   pArea->pSort = NULL;

   return errCode;
}

/*
 * recreate tags in index file
 */
static ERRCODE hb_ntxReIndex( LPNTXINDEX pIndex )
{
   ERRCODE errCode = FAILURE;
   int i;

   if( hb_ntxIndexLockWrite( pIndex, FALSE ) )
   {
      errCode = SUCCESS;
      hb_ntxIndexTrunc( pIndex );

      for( i = 0; i < pIndex->iTags; i++ )
      {
         LPTAGINFO pTag = pIndex->lpTags[ i ];
         pTag->HeadBlock = pTag->RootBlock = pTag->keyCount = 0;
         pTag->HdrChanged = TRUE;
         errCode = hb_ntxTagCreate( pTag, TRUE );
         if( errCode != SUCCESS )
            break;
      }
      hb_ntxIndexUnLockWrite( pIndex );
   }
   return errCode;
}


/* ************************************************************************* */

/* Implementation of exported functions */

static ERRCODE ntxGoBottom( NTXAREAP pArea )
{
   ERRCODE retval;

   HB_TRACE(HB_TR_DEBUG, ("ntxGoBottom(%p)", pArea));

   if( SELF_GOCOLD( ( AREAP ) pArea ) == FAILURE )
      return FAILURE;

   if( !pArea->lpCurTag )
      return SUPER_GOBOTTOM( ( AREAP ) pArea );

   if( pArea->lpdbPendingRel && pArea->lpdbPendingRel->isScoped )
      SELF_FORCEREL( ( AREAP ) pArea );

   if( ! hb_ntxTagLockRead( pArea->lpCurTag ) )
      return FAILURE;
   hb_ntxTagRefreshScope( pArea->lpCurTag );

   hb_ntxTagGoBottom( pArea->lpCurTag );

   pArea->fTop = FALSE;
   pArea->fBottom = TRUE;

   if( pArea->lpCurTag->TagEOF )
      retval = SELF_GOTO( ( AREAP ) pArea, 0 );
   else
   {
      retval = SELF_GOTO( ( AREAP ) pArea, pArea->lpCurTag->CurKeyInfo->Xtra );
      if( retval != FAILURE && pArea->fPositioned )
         retval = SELF_SKIPFILTER( ( AREAP ) pArea, -1 );
   }
   hb_ntxTagUnLockRead( pArea->lpCurTag );

   return retval;
}

static ERRCODE ntxGoTop( NTXAREAP pArea )
{
   ERRCODE retval;

   HB_TRACE(HB_TR_DEBUG, ("ntxGoTop(%p)", pArea));

   if( SELF_GOCOLD( ( AREAP ) pArea ) == FAILURE )
      return FAILURE;

   if( !pArea->lpCurTag )
      return SUPER_GOTOP( ( AREAP ) pArea );

   if( pArea->lpdbPendingRel && pArea->lpdbPendingRel->isScoped )
      SELF_FORCEREL( ( AREAP ) pArea );

   if( ! hb_ntxTagLockRead( pArea->lpCurTag ) )
      return FAILURE;
   hb_ntxTagRefreshScope( pArea->lpCurTag );

   hb_ntxTagGoTop( pArea->lpCurTag );

   pArea->fTop = TRUE;
   pArea->fBottom = FALSE;

   if( pArea->lpCurTag->TagEOF )
      retval = SELF_GOTO( ( AREAP ) pArea, 0 );
   else
   {
      retval = SELF_GOTO( ( AREAP ) pArea, pArea->lpCurTag->CurKeyInfo->Xtra );
      if( retval != FAILURE && pArea->fPositioned )
         retval = SELF_SKIPFILTER( ( AREAP ) pArea, 1 );
   }
   hb_ntxTagUnLockRead( pArea->lpCurTag );

   return retval;
}

static ERRCODE ntxSeek( NTXAREAP pArea, BOOL fSoftSeek, PHB_ITEM pItem, BOOL fFindLast )
{
   HB_TRACE(HB_TR_DEBUG, ("ntxSeek(%p, %d, %p, %d)", pArea, fSoftSeek, pItem, fFindLast));

   if( SELF_GOCOLD( ( AREAP ) pArea ) == FAILURE )
      return FAILURE;

   if( ! pArea->lpCurTag )
   {
      hb_ntxErrorRT( pArea, EG_NOORDER, EDBF_NOTINDEXED, NULL, 0, EF_CANDEFAULT );
      return FAILURE;
   }
   else
   {
      LPKEYINFO pKey;
      ERRCODE retval = SUCCESS;
      BOOL  fEOF = FALSE, fLast;
      USHORT uiLen;
      ULONG ulRec;

      if( pArea->lpdbPendingRel && pArea->lpdbPendingRel->isScoped )
         SELF_FORCEREL( ( AREAP ) pArea );

      pArea->fTop = pArea->fBottom = FALSE;
      pArea->fEof = FALSE;

      fLast = pArea->lpCurTag->fUsrDescend == pArea->lpCurTag->AscendKey ?
              !fFindLast : fFindLast;

      pKey = hb_ntxKeyPutItem( NULL, pItem, fLast ? NTX_MAX_REC_NUM :
                         NTX_IGNORE_REC_NUM, pArea->lpCurTag, TRUE, &uiLen );

      if( ! hb_ntxTagLockRead( pArea->lpCurTag ) )
      {
         hb_ntxKeyFree( pKey );
         return FAILURE;
      }
      hb_ntxTagRefreshScope( pArea->lpCurTag );

      if( hb_ntxTagKeyFind( pArea->lpCurTag, pKey, uiLen ) )
         ulRec = pArea->lpCurTag->CurKeyInfo->Xtra;
      else
         ulRec = 0;

      if( ( ulRec == 0 && ! fSoftSeek ) || pArea->lpCurTag->TagEOF )
         fEOF = TRUE;
      else
      {
         if( ! hb_ntxInBottomScope( pArea->lpCurTag, pArea->lpCurTag->CurKeyInfo->key ) )
            fEOF = TRUE;
         else if( ! hb_ntxInTopScope( pArea->lpCurTag, pArea->lpCurTag->CurKeyInfo->key ) )
         {
            hb_ntxTagGoTop( pArea->lpCurTag );
            if( pArea->lpCurTag->CurKeyInfo->Xtra == 0 ||
                pArea->lpCurTag->TagEOF )
               fEOF = TRUE;
         }
      }
      hb_ntxTagUnLockRead( pArea->lpCurTag );
      if( !fEOF )
      {
         retval = SELF_GOTO( ( AREAP ) pArea, pArea->lpCurTag->CurKeyInfo->Xtra );
         if( retval != FAILURE && pArea->fPositioned )
         {
            retval = SELF_SKIPFILTER( ( AREAP ) pArea, fFindLast ? -1 : 1 );
            if( retval != FAILURE && ulRec && pArea->fPositioned )
            {
               pArea->fFound = ( ulRec == pArea->ulRecNo ||
                     hb_ntxValCompare( pArea->lpCurTag, pKey->key, uiLen,
                                       pArea->lpCurTag->CurKeyInfo->key,
                                       pArea->lpCurTag->KeyLength, FALSE ) == 0 );
               if( ! pArea->fFound && ! fSoftSeek )
                  fEOF = TRUE;
            }
         }
      }
      if( retval != FAILURE && ( fEOF ||
          !hb_ntxKeyInScope( pArea->lpCurTag, pArea->lpCurTag->CurKeyInfo ) ) )
      {
         retval = SELF_GOTO( ( AREAP ) pArea, 0 );
      }
      if( pArea->fPositioned || pArea->ulRecNo != 1 )
         pArea->fBof = FALSE;
      hb_ntxKeyFree( pKey );
      return retval;
   }
}

static ERRCODE ntxSkipRaw( NTXAREAP pArea, LONG lToSkip )
{
   ERRCODE retval;
   BOOL fOut = FALSE, fForward;

   HB_TRACE(HB_TR_DEBUG, ("ntxSkipRaw(%p, %ld)", pArea, lToSkip));

   if( SELF_GOCOLD( ( AREAP ) pArea ) == FAILURE )
      return FAILURE;

   if( ! pArea->lpCurTag || lToSkip == 0 )
      return SUPER_SKIPRAW( ( AREAP ) pArea, lToSkip );

   if( ! hb_ntxTagLockRead( pArea->lpCurTag ) )
      return FAILURE;
   hb_ntxTagRefreshScope( pArea->lpCurTag );

   fForward = ( lToSkip > 0 );

   if( ! hb_ntxCurKeyRefresh( pArea->lpCurTag ) )
   {
      if( fForward || pArea->fPositioned )
         fOut = TRUE;
      else
      {
         hb_ntxTagGoBottom( pArea->lpCurTag );
         fOut = pArea->lpCurTag->TagEOF;
         lToSkip++;
      }
   }

   if( fForward )
   {
      while( !fOut && !pArea->lpCurTag->TagEOF && lToSkip-- > 0 )
      {
         hb_ntxTagSkipNext( pArea->lpCurTag );
      }
      retval = SELF_GOTO( ( AREAP ) pArea,
                                    ( pArea->lpCurTag->TagEOF || fOut ) ? 0 :
                                    pArea->lpCurTag->CurKeyInfo->Xtra );
   }
   else /* if( lToSkip < 0 ) */
   {
      while( !fOut && !pArea->lpCurTag->TagBOF && lToSkip++ < 0 )
      {
         hb_ntxTagSkipPrev( pArea->lpCurTag );
      }
      if( fOut || pArea->lpCurTag->TagBOF )
      {
         hb_ntxTagGoTop( pArea->lpCurTag );
         fOut = TRUE;
      }
      retval = SELF_GOTO( ( AREAP ) pArea, pArea->lpCurTag->TagEOF ? 0 :
                                          pArea->lpCurTag->CurKeyInfo->Xtra );
      pArea->fBof = fOut;
   }

   hb_ntxTagUnLockRead( pArea->lpCurTag );
   /* Update Bof and Eof flags */
   /*
   if( fForward )
      pArea->fBof = FALSE;
   else
      pArea->fEof = FALSE;
   */
   return retval;
}

/*
 * Flush _system_ buffers to disk
 */
static ERRCODE ntxFlush( NTXAREAP pArea )
{
   ERRCODE uiError;

   HB_TRACE(HB_TR_DEBUG, ("ntxFlush(%p)", pArea));

   uiError = SELF_GOCOLD( ( AREAP ) pArea );
   if( uiError == SUCCESS )
   {
      uiError = SUPER_FLUSH( ( AREAP ) pArea );

      if( hb_set.HB_SET_HARDCOMMIT )
      {
         LPNTXINDEX pIndex = pArea->lpIndexes;
         while( pIndex )
         {
            if( pIndex->fFlush /* && !pIndex->Temporary */ )
            {
               hb_fsCommit( pIndex->DiskFile );
               pIndex->fFlush = FALSE;
            }
            pIndex = pIndex->pNext;
         }
      }
   }

   return uiError;
}

/*
 * Perform a write of WorkArea memory to the data store.
 */
static ERRCODE ntxGoCold( NTXAREAP pArea )
{
   BOOL fRecordChanged = pArea->fRecordChanged;
   BOOL fAppend = pArea->fAppend;

   HB_TRACE(HB_TR_DEBUG, ("ntxGoCold(%p)", pArea));

   if( SUPER_GOCOLD( ( AREAP ) pArea ) == SUCCESS )
   {
      if( fRecordChanged || pArea->fNtxAppend )
      {
         if( fAppend && pArea->fShared )
         {
            if( pArea->fNtxAppend )
               hb_errInternal( 9999, "ntxGoCold: multiple appending without GOCOLD.", "", "" );
            pArea->fNtxAppend = TRUE;
         }
         else
         {
            LPNTXINDEX pIndex = pArea->lpIndexes;
            LPTAGINFO pTag;
            LPKEYINFO pKey;
            BOOL fAdd, fDel, fLck = FALSE;
            int i;

            /* The pending relation may move the record pointer so we should
               disable them for KEY/FOR evaluation */
            LPDBRELINFO lpdbPendingRel = pArea->lpdbPendingRel;
            pArea->lpdbPendingRel = NULL;

            if( pArea->fShared )
            {
               fAppend = pArea->fNtxAppend;
               pArea->fNtxAppend = FALSE;
            }

            while( pIndex )
            {
               for( i = 0; i < pIndex->iTags; i++ )
               {
                  pTag = pIndex->lpTags[ i ];
                  if( pIndex->fReadonly || pTag->Custom ||
                      ( pTag->Owner->Compound && !pTag->HeadBlock ) ||
                      ( fAppend && pTag->ChgOnly ) )
                     continue;

                  pKey = hb_ntxEvalKey( NULL, pTag );

                  fAdd = ( pTag->pForItem == NULL ||
                           hb_ntxEvalCond( pArea, pTag->pForItem, TRUE ) );
                  if( fAppend )
                  {
                     fDel = FALSE;
                  }
                  else
                  {
                     if( hb_ntxValCompare( pTag, pKey->key, pTag->KeyLength,
                          pTag->HotKeyInfo->key, pTag->KeyLength, TRUE ) == 0 )
                     {
                        if( pTag->HotFor ? fAdd : !fAdd )
                           fAdd = fDel = FALSE;
                        else
                           fDel = !fAdd;
                     }
                     else
                     {
                        fDel = pTag->HotFor || pTag->Partial;
                     }
                  }
                  if( fDel || fAdd )
                  {
                     if( !fLck )
                     {
                        if( !hb_ntxIndexLockWrite( pIndex, TRUE ) )
                        {
                           hb_ntxKeyFree( pKey );
                           break;
                        }
                        fLck = TRUE;
                        if( ( pTag->Owner->Compound && !pTag->HeadBlock ) ||
                            !pTag->RootBlock )
                           fAdd = fDel = FALSE;
                     }
                     if( fDel )
                     {
                        if( hb_ntxTagKeyDel( pTag, pTag->HotKeyInfo ) )
                        {
                           if( !pIndex->fShared && pTag->keyCount &&
                               hb_ntxKeyInScope( pTag, pTag->HotKeyInfo ) )
                              pTag->keyCount--;
                        }
                        else
                        {
                           if( pTag->ChgOnly )
                              fAdd = FALSE;
                           else if( !pTag->Partial && !pTag->UniqueKey )
                              hb_ntxErrorRT( pTag->Owner->Owner,
                                             EG_CORRUPTION, EDBF_CORRUPT,
                                             pTag->Owner->IndexName, 0, 0 );
                        }
                     }
                     if( fAdd )
                     {
                        if( hb_ntxTagKeyAdd( pTag, pKey ) )
                        {
                           if( !pIndex->fShared && pTag->keyCount &&
                               hb_ntxKeyInScope( pTag, pKey ) )
                              pTag->keyCount++;
                        }
                     }
                  }
                  hb_ntxKeyFree( pKey );
               }
               if( fLck )
               {
                  hb_ntxIndexUnLockWrite( pIndex );
                  fLck = FALSE;
               }
               pIndex = pIndex->pNext;
            }

            /* Restore disabled pending relation */
            pArea->lpdbPendingRel = lpdbPendingRel;
         }
      }
      return SUCCESS;
   }
   return FAILURE;
}

/*
 * Mark the WorkArea data buffer as hot.
 */
static ERRCODE ntxGoHot( NTXAREAP pArea )
{
   ERRCODE errCode;

   HB_TRACE(HB_TR_DEBUG, ("ntxGoHot(%p)", pArea));

   errCode = SUPER_GOHOT( ( AREAP ) pArea );
   if( errCode == SUCCESS )
   {
      if( !pArea->fNtxAppend )
      {
         LPNTXINDEX pIndex = pArea->lpIndexes;
         LPTAGINFO pTag;
         int i;

         while( pIndex )
         {
            if( !pIndex->fReadonly )
            {
               for( i = 0; i < pIndex->iTags; i++ )
               {
                  pTag = pIndex->lpTags[ i ];
                  if( !pTag->Custom )
                  {
                     pTag->HotKeyInfo = hb_ntxEvalKey( pTag->HotKeyInfo, pTag );
                     pTag->HotFor = ( pTag->pForItem == NULL ||
                                 hb_ntxEvalCond( pArea, pTag->pForItem, TRUE ) );
                  }
               }
            }
            pIndex = pIndex->pNext;
         }
      }
      return SUCCESS;
   }
   return errCode;
}

/*
 * Close the table in the WorkArea.
 */
static ERRCODE ntxClose( NTXAREAP pArea )
{
   ERRCODE errCode;

   HB_TRACE(HB_TR_DEBUG, ("ntxClose(%p)", pArea));

   if( SELF_GOCOLD( ( AREAP ) pArea ) == FAILURE )
      return FAILURE;

   errCode = SUPER_CLOSE( ( AREAP ) pArea );

   if( errCode == SUCCESS )
   {
      if( pArea->pSort )
      {
         hb_ntxSortFree( pArea->pSort, TRUE );
         pArea->pSort = NULL;
      }

      SELF_ORDLSTCLEAR( ( AREAP ) pArea );

      /* close also production indexes if any */
      while( pArea->lpIndexes )
      {
         LPNTXINDEX pIndex = pArea->lpIndexes;
         pArea->lpIndexes = pIndex->pNext;
         hb_ntxIndexFree( pIndex );
      }

#ifdef HB_NTX_DEBUG_DISP
      printf("\r\n#reads=%ld, #writes=%ld\r\n", s_rdNO, s_wrNO ); fflush(stdout);
#endif
   }

   return errCode;
}

/*
 * Retrieve the size of the WorkArea structure.
 */
static ERRCODE ntxStructSize( NTXAREAP pArea, USHORT * uiSize )

{
   HB_TRACE(HB_TR_DEBUG, ("ntxStrucSize(%p, %p)", pArea, uiSize));
   HB_SYMBOL_UNUSED( pArea );

   * uiSize = sizeof( NTXAREA );
   return SUCCESS;
}

/*
 * Open a data store in the WorkArea.
 */
static ERRCODE ntxOpen( NTXAREAP pArea, LPDBOPENINFO pOpenInfo )
{
   ERRCODE errCode;

   HB_TRACE(HB_TR_DEBUG, ("ntxOpen(%p, %p)", pArea, pOpenInfo));

   errCode = SUPER_OPEN( ( AREAP ) pArea, pOpenInfo );

   if( errCode == SUCCESS && s_fStruct &&
       ( s_fStrictStruct ? pArea->fHasTags : hb_set.HB_SET_AUTOPEN ) )
   {
      char szFileName[ _POSIX_PATH_MAX + 1 ];

      hb_ntxCreateFName( pArea, NULL, NULL, szFileName, NULL );
      if ( hb_spFile( ( BYTE * ) szFileName, NULL ) )
      {
         DBORDERINFO pOrderInfo;

         pOrderInfo.itmResult = hb_itemPutNI( NULL, 0 );
         pOrderInfo.atomBagName = hb_itemPutC( NULL, szFileName );
         pOrderInfo.itmNewVal = NULL;
         pOrderInfo.itmOrder  = NULL;
         errCode = SELF_ORDLSTADD( ( AREAP ) pArea, &pOrderInfo );
         if( errCode == SUCCESS )
         {
            pOrderInfo.itmOrder  = hb_itemPutNI( NULL, hb_set.HB_SET_AUTORDER );
            errCode = SELF_ORDLSTFOCUS( ( AREAP ) pArea, &pOrderInfo );
            hb_itemRelease( pOrderInfo.itmOrder );
            if( errCode == SUCCESS )
               errCode = SELF_GOTOP( ( AREAP ) pArea );
         }
         hb_itemRelease( pOrderInfo.atomBagName );
         hb_itemRelease( pOrderInfo.itmResult );
      }
   }

   return errCode;
}

static ERRCODE ntxSysName( NTXAREAP pArea, BYTE * pBuffer )
{
   HB_TRACE(HB_TR_DEBUG, ("ntxSysName(%p, %p)", pArea, pBuffer));
   HB_SYMBOL_UNUSED( pArea );

   strncpy( ( char * ) pBuffer, "DBFNTX", 7 /* HARBOUR_MAX_RDD_DRIVERNAME_LENGTH */ );
   return SUCCESS;
}

static ERRCODE ntxPack( NTXAREAP pArea )
{
   ERRCODE errCode;
   HB_TRACE(HB_TR_DEBUG, ("ntxPack(%p)", pArea ));

   errCode = SUPER_PACK( ( AREAP ) pArea );
   if( errCode == SUCCESS )
      return SELF_ORDLSTREBUILD( ( AREAP ) pArea );

   return errCode;
}

static ERRCODE ntxZap( NTXAREAP pArea )
{
   ERRCODE errCode;

   HB_TRACE(HB_TR_DEBUG, ("ntxZap(%p)", pArea ));

   errCode = SUPER_ZAP( ( AREAP ) pArea );
   if( errCode == SUCCESS )
      return SELF_ORDLSTREBUILD( ( AREAP ) pArea );

   return errCode;
}

static ERRCODE ntxOrderCreate( NTXAREAP pArea, LPDBORDERCREATEINFO pOrderInfo )
{
   PHB_ITEM pResult, pKeyExp, pForExp = NULL;
   int iLen, iDec, iTag, i;
   char szFileName[ _POSIX_PATH_MAX + 1 ], szSpFile[ _POSIX_PATH_MAX + 1 ],
        szTagName[ NTX_MAX_TAGNAME + 1 ], * szKey, * szFor = NULL;
   LPNTXINDEX pIndex, * pIndexPtr;
   LPTAGINFO pTag = NULL;
   ERRCODE errCode;
   ULONG ulRecNo;
   BOOL fCompound, fTagName, fBagName, fProd, fLocked = FALSE,
        fAscend = TRUE, fCustom = FALSE, fTemporary = FALSE, fExclusive = FALSE;
   BYTE bType;

   HB_TRACE(HB_TR_DEBUG, ("ntxOrderCreate(%p, %p)", pArea, pOrderInfo));

   errCode = SELF_GOCOLD( ( AREAP ) pArea );
   if( errCode != SUCCESS )
      return errCode;

   if( pArea->lpdbPendingRel )
   {
      errCode = SELF_FORCEREL( ( AREAP ) pArea );
      if( errCode != SUCCESS )
         return errCode;
   }

   szKey = hb_itemGetCPtr( pOrderInfo->abExpr );
   /* If we have a codeblock for the expression, use it */
   if( pOrderInfo->itmCobExpr )
      pKeyExp = hb_itemNew( pOrderInfo->itmCobExpr );
   else /* Otherwise, try compiling the key expression string */
   {
      errCode = SELF_COMPILE( ( AREAP ) pArea, ( BYTE * ) szKey );
      if( errCode != SUCCESS )
         return errCode;
      pKeyExp = pArea->valResult;
      pArea->valResult = NULL;
   }

   /* Get a blank record before testing expression */
   ulRecNo = pArea->ulRecNo;
   errCode = SELF_GOTO( ( AREAP ) pArea, 0 );
   if( errCode != SUCCESS )
      return errCode;

   errCode = SELF_EVALBLOCK( ( AREAP ) pArea, pKeyExp );
   if( errCode != SUCCESS )
   {
      hb_vmDestroyBlockOrMacro( pKeyExp );
      SELF_GOTO( ( AREAP ) pArea, ulRecNo );
      return errCode;
   }
   pResult = pArea->valResult;
   pArea->valResult = NULL;

   bType = hb_ntxItemType( pResult );
   iLen = iDec = 0;
   switch( bType )
   {
      case 'N':
         hb_itemGetNLen( pResult, &iLen, &iDec );
         if( iDec )
            iLen += iDec + 1;
         break;
      case 'D':
         iLen = 8;
         break;
      case 'L':
         iLen = 1;
         break;
      case 'C':
         iLen = hb_itemGetCLen( pResult );
         if( iLen > NTX_MAX_KEY )
            iLen = NTX_MAX_KEY;
         break;
      default:
         bType = 'U';
   }
   hb_itemRelease( pResult );

   /* Make sure KEY has proper type and iLen is not 0 */
   if( bType == 'U' || iLen == 0 )
   {
      hb_vmDestroyBlockOrMacro( pKeyExp );
      SELF_GOTO( ( AREAP ) pArea, ulRecNo );
      hb_ntxErrorRT( pArea, bType == 'U' ? EG_DATATYPE : EG_DATAWIDTH,
                     1026, NULL, 0, 0 );
      return FAILURE;
   }

   if( pArea->lpdbOrdCondInfo )
   {
      fAscend = !pArea->lpdbOrdCondInfo->fDescending;
      fCustom = pArea->lpdbOrdCondInfo->fCustom;
      fTemporary = pArea->lpdbOrdCondInfo->fTemporary;
      fExclusive = pArea->lpdbOrdCondInfo->fExclusive;
      /* Check conditional expression */
      szFor = ( char * ) pArea->lpdbOrdCondInfo->abFor;
      if( pArea->lpdbOrdCondInfo->itmCobFor )
         /* If we have a codeblock for the conditional expression, use it */
         pForExp = hb_itemNew( pArea->lpdbOrdCondInfo->itmCobFor );
      else if( szFor )
      {
         /* Otherwise, try compiling the conditional expression string */
         errCode = SELF_COMPILE( ( AREAP ) pArea, ( BYTE * ) szFor );
         if( errCode != SUCCESS )
         {
            hb_vmDestroyBlockOrMacro( pKeyExp );
            SELF_GOTO( ( AREAP ) pArea, ulRecNo );
            return errCode;
         }
         pForExp = pArea->valResult;
         pArea->valResult = NULL;
      }
   }

   /* Test conditional expression */
   if( pForExp )
   {
      BOOL fOK;

      errCode = SELF_EVALBLOCK( ( AREAP ) pArea, pForExp );
      if( errCode != SUCCESS )
      {
         hb_vmDestroyBlockOrMacro( pKeyExp );
         hb_vmDestroyBlockOrMacro( pForExp );
         SELF_GOTO( ( AREAP ) pArea, ulRecNo );
         return errCode;
      }
      fOK = hb_itemType( pArea->valResult ) == HB_IT_LOGICAL;
      hb_itemRelease( pArea->valResult );
      pArea->valResult = NULL;
      if( ! fOK )
      {
         hb_vmDestroyBlockOrMacro( pKeyExp );
         hb_vmDestroyBlockOrMacro( pForExp );
         SELF_GOTO( ( AREAP ) pArea, ulRecNo );
         hb_ntxErrorRT( pArea, EG_DATATYPE, EDBF_INVALIDFOR, NULL, 0, 0 );
         return FAILURE;
      }
   }

   SELF_GOTO( ( AREAP ) pArea, ulRecNo );

   /*
    * abBagName -> cBag, atomBagName -> cTag
    * The following scheme implemented:
    * 1. abBagName == NULL   -> add the Tag to the structural index
    *    if no compound index support then create new separate index
    *    with atomBagName
    * 2. atomBagName == NULL -> overwrite any index file of abBagName
    * 3. ads the Tag to index file
    */
   fTagName = pOrderInfo->atomBagName && pOrderInfo->atomBagName[0];
   fBagName = pOrderInfo->abBagName && pOrderInfo->abBagName[0];
#if defined( HB_NTX_NOMULTITAG )
   fCompound = FALSE;
#else
   fCompound = fTagName && s_fMultiTag;
#endif
   hb_ntxCreateFName( pArea, ( char * ) ( ( fBagName || fCompound ) ?
                      pOrderInfo->abBagName : pOrderInfo->atomBagName ),
                      &fProd, szFileName, szTagName );
   if( fTagName )
      hb_strncpyUpperTrim( szTagName, ( char * ) pOrderInfo->atomBagName, NTX_MAX_TAGNAME );

   pIndex = hb_ntxFindBag( pArea, szFileName );
   if( pIndex && !fCompound )
   {
      pIndexPtr = &pArea->lpIndexes;
      while( *pIndexPtr )
      {
         if( pIndex == *pIndexPtr )
         {
            *pIndexPtr = pIndex->pNext;
            hb_ntxIndexFree( pIndex );
            break;
         }
         pIndexPtr = &(*pIndexPtr)->pNext;
      }
      pIndex = NULL;
   }

   if( pIndex )
   {
      if( pIndex->fReadonly )
      {
         hb_vmDestroyBlockOrMacro( pKeyExp );
         if( pForExp != NULL )
            hb_vmDestroyBlockOrMacro( pForExp );
         hb_ntxErrorRT( pArea, EG_READONLY, EDBF_READONLY, pIndex->IndexName, 0, 0 );
         return FAILURE;
      }
#if 0 /* enable this code if you want to forbid tag deleting in shared mode */
      else if( pIndex->fShared )
      {
         hb_vmDestroyBlockOrMacro( pKeyExp );
         if( pForExp != NULL )
            hb_vmDestroyBlockOrMacro( pForExp );
         hb_ntxErrorRT( pArea, EG_SHARED, EDBF_SHARED, pIndex->IndexName, 0, 0 );
         return FAILURE;
      }
#endif
   }
   else
   {
      FHANDLE hFile;
      BOOL bRetry, fOld, fShared = pArea->fShared && !fTemporary && !fExclusive;
      USHORT uiFlags = FO_READWRITE | ( fShared ? FO_DENYNONE : FO_EXCLUSIVE );

      fOld = fCompound;
      do
      {
         if( fTemporary )
         {
            hFile = hb_fsCreateTemp( NULL, NULL, FC_NORMAL, ( BYTE * ) szSpFile );
            fOld = FALSE;
         }
         else
         {
            hFile = hb_fsExtOpen( ( BYTE * ) szFileName, NULL, uiFlags |
                                  ( fOld ? FXO_APPEND : FXO_TRUNCATE ) |
                                  FXO_DEFAULTS | FXO_SHARELOCK | FXO_COPYNAME,
                                  NULL, NULL );
         }
         if( hFile == FS_ERROR )
            bRetry = ( hb_ntxErrorRT( pArea, EG_CREATE, EDBF_CREATE, szFileName,
                                      hb_fsError(), EF_CANRETRY | EF_CANDEFAULT ) == E_RETRY );
         else
         {
            bRetry = FALSE;
            if( fOld )
               fOld = ( hb_fsSeekLarge( hFile, 0, FS_END ) != 0 );
         }
      } while( bRetry );

      if( hFile == FS_ERROR )
      {
         hb_vmDestroyBlockOrMacro( pKeyExp );
         if( pForExp != NULL )
            hb_vmDestroyBlockOrMacro( pForExp );
         /* hb_ntxSetTagNumbers() */
         return FAILURE;
      }

      pIndex = hb_ntxIndexNew( pArea );
      pIndex->IndexName = hb_strdup( szFileName );
      pIndex->fReadonly = FALSE;
      pIndex->fShared = fShared;
      pIndex->DiskFile = hFile;
      pIndex->fDelete = fTemporary;
      if( fTemporary )
         pIndex->RealName = hb_strdup( szSpFile );
      else
         pIndex->Production = fProd;

      pIndexPtr = &pArea->lpIndexes;
      while( *pIndexPtr )
         pIndexPtr = &(*pIndexPtr)->pNext;
      *pIndexPtr = pIndex;
      if( fOld )
      {
         if( !hb_ntxIndexLockWrite( pIndex, TRUE ) )
            errCode = FAILURE;
         else
         {
            errCode = hb_ntxIndexLoad( pIndex, szTagName );
            if( errCode != SUCCESS )
               hb_ntxIndexUnLockWrite( pIndex );
            else
               fLocked = TRUE;
         }
         if( errCode != SUCCESS )
         {
            *pIndexPtr = pIndex->pNext;
            hb_ntxIndexFree( pIndex );
            hb_vmDestroyBlockOrMacro( pKeyExp );
            if( pForExp != NULL )
               hb_vmDestroyBlockOrMacro( pForExp );
            /* hb_ntxSetTagNumbers() */
            hb_ntxErrorRT( pArea, EG_CORRUPTION, EDBF_CORRUPT, szFileName, 0, 0 );
            return errCode;
         }
      }
      else
      {
         pIndex->LargeFile = ( pIndex->Owner->bLockType == DB_DBFLOCK_XHB64 );
      }
   }

   iTag = hb_ntxFindTagByName( pIndex, szTagName );
   fCompound = ( pIndex->iTags > ( iTag ? 1 : 0 ) );

   if( ! iTag && pIndex->iTags == CTX_MAX_TAGS )
   {
      hb_vmDestroyBlockOrMacro( pKeyExp );
      if( pForExp != NULL )
         hb_vmDestroyBlockOrMacro( pForExp );
      /* hb_ntxSetTagNumbers() */
      hb_ntxErrorRT( pArea, EG_LIMIT, EDBF_LIMITEXCEEDED, pIndex->IndexName, 0, 0 );
      return FAILURE;
   }

   if( !fLocked && !hb_ntxIndexLockWrite( pIndex, fCompound ) )
   {
      errCode = FAILURE;
   }
   else
   {
      if( pIndex->Compound != fCompound )
      {
         pIndex->Compound = fCompound;
         if( fCompound )
         {
            if( !pIndex->HeaderBuff )
               pIndex->HeaderBuff = ( BYTE * ) hb_xgrab( NTXBLOCKSIZE );
            memset( pIndex->HeaderBuff, 0, NTXBLOCKSIZE );
            pIndex->fValidHeader = TRUE;
         }
         for( i = 0; i < pIndex->iTags; i++ )
         {
            pIndex->lpTags[ i ]->HdrChanged = TRUE;
            pIndex->lpTags[ i ]->HeadBlock = 0;
            if( fCompound )
               hb_ntxIndexTagAdd( pIndex, pIndex->lpTags[ i ] );
         }
      }
      pTag = hb_ntxTagNew( pIndex, szTagName, fTagName,
                           szKey, pKeyExp, bType, (USHORT) iLen, (USHORT) iDec,
                           szFor, pForExp,
                           fAscend, pOrderInfo->fUnique, fCustom, s_fSortRecNo );
      pTag->Partial = ( pArea->lpdbOrdCondInfo && !pArea->lpdbOrdCondInfo->fAll );

      if( ! pIndex->Compound )
      {
         while( pIndex->iTags )
            hb_ntxTagDelete( pIndex->lpTags[ 0 ] );
         hb_ntxIndexTrunc( pIndex );
         iTag = 0;
      }

      if( iTag )
      {
         pTag->HeadBlock = pIndex->lpTags[ iTag - 1 ]->HeadBlock;
         if( pIndex->lpTags[ iTag - 1 ]->RootBlock &&
             ! hb_ntxTagPagesFree( pIndex->lpTags[ iTag - 1 ],
                                   pIndex->lpTags[ iTag - 1 ]->RootBlock ) )
         {
            errCode = FAILURE;
         }
         else
         {
            hb_ntxTagFree( pIndex->lpTags[ iTag - 1 ] );
            pIndex->lpTags[ iTag - 1 ] = pTag;
         }
      }
      else
      {
         hb_ntxTagAdd( pIndex, pTag );
         if( pIndex->Compound )
            hb_ntxIndexTagAdd( pIndex, pTag );
      }

      if( errCode == SUCCESS )
      {
         pIndex->Update = pIndex->Changed = pTag->HdrChanged = TRUE;
         errCode = hb_ntxTagCreate( pTag, FALSE );
      }
      hb_ntxIndexUnLockWrite( pIndex );
   }

   pIndexPtr = &pArea->lpIndexes;
   while( *pIndexPtr && *pIndexPtr != pIndex )
      pIndexPtr = &(*pIndexPtr)->pNext;

   /* It should not happen, reintrance? */
   if( !*pIndexPtr )
      return FAILURE;

   if( errCode != SUCCESS )
   {
      *pIndexPtr = pIndex->pNext;
      hb_ntxIndexFree( pIndex );
      /* hb_ntxSetTagNumbers() */
      return errCode;
   }

   if( !pArea->lpdbOrdCondInfo || !pArea->lpdbOrdCondInfo->fAdditive )
   {
      *pIndexPtr = pIndex->pNext;
      pIndex->pNext = NULL;
      SELF_ORDLSTCLEAR( ( AREAP ) pArea );
      pIndexPtr = &pArea->lpIndexes;
      while( *pIndexPtr )
         pIndexPtr = &(*pIndexPtr)->pNext;
      *pIndexPtr = pIndex;
   }
   if( pIndex->Production && !pArea->fHasTags &&
       s_fStruct && ( s_fStrictStruct || hb_set.HB_SET_AUTOPEN ) )
   {
      pArea->fHasTags = TRUE;
      if( !pArea->fReadonly && ( pArea->dbfHeader.bHasTags & 0x01 ) == 0 )
         SELF_WRITEDBHEADER( ( AREAP ) pArea );
   }
   /* hb_ntxSetTagNumbers() */
   pArea->lpCurTag = pTag;
   SELF_ORDSETCOND( ( AREAP ) pArea, NULL );
   return SELF_GOTOP( ( AREAP ) pArea );
}

static ERRCODE ntxOrderDestroy( NTXAREAP pArea, LPDBORDERINFO pOrderInfo )
{
   ERRCODE errCode;

   HB_TRACE(HB_TR_DEBUG, ("ntxOrderDestroy(%p, %p)", pArea, pOrderInfo));

   errCode = SELF_GOCOLD( ( AREAP ) pArea );
   if( errCode != SUCCESS )
      return errCode;

   if( pArea->lpdbPendingRel )
   {
      errCode = SELF_FORCEREL( ( AREAP ) pArea );
      if( errCode != SUCCESS )
         return errCode;
   }

   if( pOrderInfo->itmOrder )
   {
      LPTAGINFO pTag = hb_ntxFindTag( pArea, pOrderInfo->itmOrder, pOrderInfo->atomBagName );

      if( pTag )
      {
         LPNTXINDEX pIndex = pTag->Owner, *pIndexPtr;

         if( pIndex->iTags == 1 )
         {
            BOOL fProd = pIndex->Production;
            pIndexPtr = &pArea->lpIndexes;
            while( *pIndexPtr != pIndex )
               pIndexPtr = &(*pIndexPtr)->pNext;
            *pIndexPtr = pIndex->pNext;
            pIndex->fDelete = TRUE;
            hb_ntxIndexFree( pIndex );
            if( fProd && pArea->fHasTags &&
                s_fStruct && ( s_fStrictStruct || hb_set.HB_SET_AUTOPEN ) )
            {
               pArea->fHasTags = FALSE;
               if( !pArea->fReadonly && ( pArea->dbfHeader.bHasTags & 0x01 ) != 0 )
                  SELF_WRITEDBHEADER( ( AREAP ) pArea );
            }
         }
         else if( pIndex->fReadonly )
         {
            hb_ntxErrorRT( pArea, EG_READONLY, EDBF_READONLY, pIndex->IndexName, 0, 0 );
            return FAILURE;
         }
#if 0 /* enable this code if you want to forbid tag deleting in shared mode */
         else if( pIndex->fShared )
         {
            hb_ntxErrorRT( pArea, EG_SHARED, EDBF_SHARED, pIndex->IndexName, 0, 0 );
            return FAILURE;
         }
#endif
         else if( !hb_ntxIndexLockWrite( pIndex, TRUE ) )
         {
            return FAILURE;
         }
         else
         {
            errCode = hb_ntxTagSpaceFree( pTag );
            hb_ntxIndexUnLockWrite( pIndex );
         }
         /* hb_ntxSetTagNumbers() */
      }
   }

   return errCode;
}

static ERRCODE ntxOrderInfo( NTXAREAP pArea, USHORT uiIndex, LPDBORDERINFO pInfo )
{
   LPTAGINFO pTag;
   HB_TRACE(HB_TR_DEBUG, ("ntxOrderInfo(%p, %hu, %p)", pArea, uiIndex, pInfo));

   switch( uiIndex )
   {
      case DBOI_BAGEXT:
         hb_itemClear( pInfo->itmResult );
         return SELF_RDDINFO( SELF_RDDNODE( pArea ), RDDI_ORDBAGEXT, 0, pInfo->itmResult );
      case DBOI_EVALSTEP:
         hb_itemPutNL( pInfo->itmResult,
                  pArea->lpdbOrdCondInfo ? pArea->lpdbOrdCondInfo->lStep : 0 );
         return SUCCESS;
      case DBOI_KEYSINCLUDED:
         hb_itemPutNL( pInfo->itmResult,
                       pArea->pSort ? pArea->pSort->ulTotKeys : 0 );
         return SUCCESS;
      case DBOI_I_TAGNAME:
         hb_itemPutC( pInfo->itmResult,
                      pArea->pSort ? pArea->pSort->pTag->TagName : NULL );
         return SUCCESS;
      case DBOI_I_BAGNAME:
         hb_itemPutC( pInfo->itmResult, pArea->pSort ?
                      pArea->pSort->pTag->Owner->IndexName : NULL );
         return SUCCESS;
      case DBOI_ISREINDEX:
         hb_itemPutL( pInfo->itmResult,
                      pArea->pSort ? pArea->pSort->fReindex : FALSE );
         return SUCCESS;
      case DBOI_LOCKOFFSET:
      case DBOI_HPLOCKING:
      {
         HB_FOFFSET ulPos, ulPool;
         hb_dbfLockIdxGetData( pArea->bLockType, &ulPos, &ulPool );
         if( uiIndex == DBOI_LOCKOFFSET )
            hb_itemPutNInt( pInfo->itmResult, ulPos );
         else
            hb_itemPutL( pInfo->itmResult, ulPool > 0 );
         return SUCCESS;
      }
      case DBOI_ORDERCOUNT:
      {
         int i = 0;
         BOOL fBag = hb_itemGetCLen( pInfo->atomBagName ) > 0;
         LPNTXINDEX pIndex = fBag ?
               hb_ntxFindBag( pArea, hb_itemGetCPtr( pInfo->atomBagName ) ) :
               pArea->lpIndexes;
         while( pIndex )
         {
            i += pIndex->iTags;
            if( fBag )
               break;
            pIndex = pIndex->pNext;
         }
         hb_itemPutNI( pInfo->itmResult, i );
         return SUCCESS;
      }
      case DBOI_BAGCOUNT:
      {
         int i = 0;
         LPNTXINDEX pIndex = pArea->lpIndexes;
         while( pIndex )
         {
            ++i;
            pIndex = pIndex->pNext;
         }
         hb_itemPutNI( pInfo->itmResult, i );
         return SUCCESS;
      }
      case DBOI_BAGNUMBER:
      {
         LPNTXINDEX pIndex = pArea->lpIndexes, pIndexSeek = NULL;
         int i = 0;

         if( hb_itemGetCLen( pInfo->atomBagName ) > 0 )
            pIndexSeek = hb_ntxFindBag( pArea,
                                        hb_itemGetCPtr( pInfo->atomBagName ) );
         else if( pArea->lpCurTag )
            pIndexSeek = pArea->lpCurTag->Owner;

         if( pIndexSeek )
         {
            do
            {
               ++i;
               if( pIndex == pIndexSeek )
                  break;
               pIndex = pIndex->pNext;
            }
            while( pIndex );
         }
         hb_itemPutNI( pInfo->itmResult, pIndex ? i : 0 );
         return SUCCESS;
      }
      case DBOI_BAGORDER:
      {
         LPNTXINDEX pIndex = pArea->lpIndexes, pIndexSeek;
         int i = 0;

         if( hb_itemGetCLen( pInfo->atomBagName ) > 0 )
            pIndexSeek = hb_ntxFindBag( pArea,
                                        hb_itemGetCPtr( pInfo->atomBagName ) );
         else
            pIndexSeek = pIndex;

         if( pIndexSeek )
         {
            ++i;
            do
            {
               if( pIndex == pIndexSeek )
                  break;
               i += pIndex->iTags;
               pIndex = pIndex->pNext;
            }
            while( pIndex );
         }
         hb_itemPutNI( pInfo->itmResult, pIndex ? i : 0 );
         return SUCCESS;
      }
   }

   if( SELF_GOCOLD( ( AREAP ) pArea ) == FAILURE )
      return FAILURE;

   pTag = hb_ntxFindTag( pArea, pInfo->itmOrder, pInfo->atomBagName );

   if( pTag )
   {
      switch( uiIndex )
      {
         case DBOI_CONDITION:
            hb_itemPutC( pInfo->itmResult, pTag->ForExpr ? pTag->ForExpr : "" );
            if( hb_itemType( pInfo->itmNewVal ) & HB_IT_STRING )
            {
               char * szForExpr = hb_itemGetCPtr( pInfo->itmNewVal );
               if( pTag->ForExpr ?
                   strncmp( pTag->ForExpr, szForExpr, NTX_MAX_EXP ) != 0 :
                   *szForExpr )
               {
                  PHB_ITEM pForItem = NULL;
                  BOOL fOK = *szForExpr == 0;
                  if( !fOK )
                  {
                     if( SELF_COMPILE( ( AREAP ) pArea, ( BYTE *) szForExpr ) == SUCCESS )
                     {
                        pForItem = pArea->valResult;
                        pArea->valResult = NULL;
                        if( SELF_EVALBLOCK( ( AREAP ) pArea, pForItem ) == SUCCESS )
                        {
                           fOK = hb_itemType( pArea->valResult ) == HB_IT_LOGICAL;
                           hb_itemRelease( pArea->valResult );
                           pArea->valResult = NULL;
                        }
                     }
                  }
                  if( fOK && hb_ntxTagLockWrite( pTag ) )
                  {
                     if( pTag->ForExpr )
                        hb_xfree( pTag->ForExpr );
                     if( pTag->pForItem )
                        hb_vmDestroyBlockOrMacro( pTag->pForItem );
                     if( pForItem )
                     {
                        pTag->ForExpr = hb_strndup( szForExpr, NTX_MAX_EXP );
                        pTag->pForItem = pForItem;
                        pForItem = NULL;
                     }
                     else
                     {
                        pTag->ForExpr = NULL;
                        pTag->pForItem = NULL;
                     }
                     pTag->Partial = TRUE;
                     pTag->HdrChanged = TRUE;
                     pTag->Owner->Update = TRUE;
                     hb_ntxTagUnLockWrite( pTag );
                  }
                  if( pForItem )
                     hb_vmDestroyBlockOrMacro( pForItem );
               }
            }
            break;
         case DBOI_EXPRESSION:
            hb_itemPutC( pInfo->itmResult, pTag->KeyExpr );
            break;
         case DBOI_BAGNAME:
            hb_itemPutC( pInfo->itmResult, pTag->Owner->IndexName );
            break;
         case DBOI_NAME:
            hb_itemPutC( pInfo->itmResult, pTag->TagName );
            break;
         case DBOI_NUMBER:
            hb_itemPutNI( pInfo->itmResult, hb_ntxFindTagNum( pArea, pTag ) );
            break;
         case DBOI_FILEHANDLE:
            hb_itemPutNInt( pInfo->itmResult, pTag->Owner->DiskFile );
            break;
         case DBOI_FULLPATH:
            hb_itemPutC( pInfo->itmResult, pTag->Owner->IndexName );
            break;
         case DBOI_KEYCOUNT:
            hb_itemPutNL( pInfo->itmResult, hb_ntxOrdKeyCount( pTag ) );
            break;
         case DBOI_POSITION:
            if( hb_itemType( pInfo->itmNewVal ) & HB_IT_NUMERIC )
               hb_itemPutL( pInfo->itmResult,
                  hb_ntxOrdKeyGoto( pTag, hb_itemGetNL( pInfo->itmNewVal ) ) );
            else
               hb_itemPutNL( pInfo->itmResult, hb_ntxOrdKeyNo( pTag ) );
            break;
         case DBOI_RELKEYPOS:
            if( hb_itemType( pInfo->itmNewVal ) & HB_IT_NUMERIC )
               hb_ntxOrdSetRelKeyPos( pTag, hb_itemGetND( pInfo->itmNewVal ) );
            else
               hb_itemPutND( pInfo->itmResult, hb_ntxOrdGetRelKeyPos( pTag ) );
            break;
         case DBOI_ISCOND:
            hb_itemPutL( pInfo->itmResult, pTag->ForExpr != NULL );
            break;
         case DBOI_ISDESC:
            hb_itemPutL( pInfo->itmResult, pTag->fUsrDescend );
            if( hb_itemType( pInfo->itmNewVal ) == HB_IT_LOGICAL )
               pTag->fUsrDescend = hb_itemGetL( pInfo->itmNewVal );
            break;
         case DBOI_UNIQUE:
            hb_itemPutL( pInfo->itmResult, pTag->UniqueKey );
            break;
         case DBOI_CUSTOM:
            if( hb_itemType( pInfo->itmNewVal ) == HB_IT_LOGICAL )
            {
               if( hb_ntxTagLockWrite( pTag ) )
               {
                  if( !pTag->Template )
                  {
                     BOOL fNewVal = hb_itemGetL( pInfo->itmNewVal );
                     if( pTag->Custom ? ! fNewVal : fNewVal )
                     {
                        pTag->Custom = fNewVal;
                        pTag->Partial = TRUE;
                        pTag->ChgOnly = FALSE;
                        pTag->HdrChanged = TRUE;
                     }
                  }
                  hb_ntxTagUnLockWrite( pTag );
               }
            }
            hb_itemPutL( pInfo->itmResult, pTag->Custom );
            break;
         case DBOI_CHGONLY:
            if( hb_itemType( pInfo->itmNewVal ) == HB_IT_LOGICAL )
            {
               if( hb_ntxTagLockWrite( pTag ) )
               {
                  if( !pTag->Custom )
                  {
                     BOOL fNewVal = hb_itemGetL( pInfo->itmNewVal );
                     if( pTag->ChgOnly ? ! fNewVal : fNewVal )
                     {
                        pTag->ChgOnly = fNewVal;
                        pTag->Partial = TRUE;
                        pTag->HdrChanged = TRUE;
                     }
                  }
                  hb_ntxTagUnLockWrite( pTag );
               }
            }
            hb_itemPutL( pInfo->itmResult, pTag->ChgOnly );
            break;
         case DBOI_TEMPLATE:
            if( hb_itemType( pInfo->itmNewVal ) == HB_IT_LOGICAL &&
                hb_itemGetL( pInfo->itmNewVal ) )
            {
               if( hb_ntxTagLockWrite( pTag ) )
               {
                  if( pTag->Custom && !pTag->Template )
                  {
                     pTag->Template = TRUE;
                     pTag->HdrChanged = TRUE;
                  }
                  hb_ntxTagUnLockWrite( pTag );
               }
            }
            hb_itemPutL( pInfo->itmResult, pTag->Template );
            break;
         case DBOI_MULTIKEY:
            if( hb_itemGetL( pInfo->itmNewVal ) )
            {
               if( hb_ntxTagLockWrite( pTag ) )
               {
                  if( pTag->Custom && !pTag->MultiKey )
                  {
                     pTag->MultiKey = TRUE;
                     pTag->HdrChanged = TRUE;
                  }
                  hb_ntxTagUnLockWrite( pTag );
               }
            }
            hb_itemPutL( pInfo->itmResult, pTag->MultiKey );
            break;
         case DBOI_PARTIAL:
            hb_itemPutL( pInfo->itmResult, pTag->Partial );
            break;
         case DBOI_SCOPETOP:
            if( pInfo->itmResult )
               hb_ntxTagGetScope( pTag, 0, pInfo->itmResult );
            if( pInfo->itmNewVal )
               hb_ntxTagSetScope( pTag, 0, pInfo->itmNewVal );
            break;
         case DBOI_SCOPEBOTTOM:
            if( pInfo->itmResult )
               hb_ntxTagGetScope( pTag, 1, pInfo->itmResult );
            if( pInfo->itmNewVal )
               hb_ntxTagSetScope( pTag, 1, pInfo->itmNewVal );
            break;
         case DBOI_SCOPESET:
            if( pInfo->itmNewVal )
            {
               hb_ntxTagSetScope( pTag, 0, pInfo->itmNewVal );
               hb_ntxTagSetScope( pTag, 1, pInfo->itmNewVal );
            }
            if( pInfo->itmResult )
               hb_itemClear( pInfo->itmResult );
            break;
         case DBOI_SCOPETOPCLEAR:
            if( pInfo->itmResult )
               hb_ntxTagGetScope( pTag, 0, pInfo->itmResult );
            hb_ntxTagClearScope( pTag, 0 );
            break;
         case DBOI_SCOPEBOTTOMCLEAR:
            if( pInfo->itmResult )
               hb_ntxTagGetScope( pTag, 1, pInfo->itmResult );
            hb_ntxTagClearScope( pTag, 1 );
            break;
         case DBOI_SCOPECLEAR:
            hb_ntxTagClearScope( pTag, 0 );
            hb_ntxTagClearScope( pTag, 1 );
            if( pInfo->itmResult )
               hb_itemClear( pInfo->itmResult );
         case DBOI_KEYADD:
            if( pTag->Owner->fReadonly )
            {
               hb_ntxErrorRT( pArea, EG_READONLY, EDBF_READONLY, pTag->Owner->IndexName, 0, 0 );
               return FAILURE;
            }
            if( pTag->Custom )
            {
               hb_itemPutL( pInfo->itmResult,
                            hb_ntxOrdKeyAdd( pTag, pInfo->itmNewVal ) );
            }
            else
            {
               hb_ntxErrorRT( pArea, 0, 1052, NULL, 0, 0 );
               return FAILURE;
            }
            break;
         case DBOI_KEYDELETE:
            if( pTag->Owner->fReadonly )
            {
               hb_ntxErrorRT( pArea, EG_READONLY, EDBF_READONLY, pTag->Owner->IndexName, 0, 0 );
               return FAILURE;
            }
            if( pTag->Custom )
            {
               hb_itemPutL( pInfo->itmResult,
                            hb_ntxOrdKeyDel( pTag, pInfo->itmNewVal ) );
            }
            else
            {
               hb_ntxErrorRT( pArea, 0, 1052, NULL, 0, 0 );
               return FAILURE;
            }
            break;
         case DBOI_KEYTYPE:
            {
               char szType[2];
               szType[0] = (char) pTag->KeyType;
               szType[1] = 0;
               hb_itemPutC( pInfo->itmResult, szType );
            }
            break;
         case DBOI_KEYSIZE:
            hb_itemPutNI( pInfo->itmResult, pTag->KeyLength );
            break;
         case DBOI_KEYDEC:
            hb_itemPutNI( pInfo->itmResult, pTag->KeyDec );
            break;
         case DBOI_KEYVAL:
            if( hb_ntxTagLockRead( pTag ) )
            {
               if( hb_ntxCurKeyRefresh( pTag ) )
                  hb_ntxKeyGetItem( pInfo->itmResult, pTag->CurKeyInfo, pTag, TRUE );
               else
                  hb_itemClear( pInfo->itmResult );
               hb_ntxTagUnLockRead( pTag );
            }
            break;
         case DBOI_SKIPUNIQUE:
            hb_itemPutL( pInfo->itmResult, hb_ntxOrdSkipUnique( pTag,
                                          hb_itemGetNL( pInfo->itmNewVal ) ) );
            break;
         case DBOI_SKIPEVAL:
         case DBOI_SKIPEVALBACK:
            hb_itemPutL( pInfo->itmResult, hb_ntxOrdSkipEval( pTag,
                              uiIndex == DBOI_SKIPEVAL, pInfo->itmNewVal ) );
            break;
         case DBOI_SKIPWILD:
         case DBOI_SKIPWILDBACK:
            hb_itemPutL( pInfo->itmResult, hb_ntxOrdSkipWild( pTag,
                              uiIndex == DBOI_SKIPWILD, pInfo->itmNewVal ) );
            break;
#if defined(__XHARBOUR__)
         case DBOI_SKIPREGEX:
         case DBOI_SKIPREGEXBACK:
            hb_itemPutL( pInfo->itmResult, hb_ntxOrdSkipRegEx( pTag,
                              uiIndex == DBOI_SKIPREGEX, pInfo->itmNewVal ) );
            break;
#endif
         case DBOI_FINDREC:
         case DBOI_FINDRECCONT:
            hb_itemPutL( pInfo->itmResult, hb_ntxOrdFindRec( pTag,
                                             hb_itemGetNL( pInfo->itmNewVal ),
                                             uiIndex == DBOI_FINDRECCONT ) );
            break;
         case DBOI_SCOPEEVAL:
            if( hb_itemType( pInfo->itmNewVal ) == HB_IT_ARRAY &&
                hb_arrayLen( pInfo->itmNewVal ) == DBRMI_SIZE &&
                hb_arrayGetPtr( pInfo->itmNewVal, DBRMI_FUNCTION ) != NULL )
            {
               hb_itemPutNL( pInfo->itmResult, hb_ntxOrdScopeEval( pTag,
                     ( HB_EVALSCOPE_FUNC )
                     hb_arrayGetPtr( pInfo->itmNewVal, DBRMI_FUNCTION ),
                     hb_arrayGetPtr( pInfo->itmNewVal, DBRMI_PARAM ),
                     hb_arrayGetItemPtr( pInfo->itmNewVal, DBRMI_LOVAL ),
                     hb_arrayGetItemPtr( pInfo->itmNewVal, DBRMI_HIVAL ) ) );
            }
            else
            {
               hb_itemPutNI( pInfo->itmResult, 0 );
            }
            break;
         case DBOI_UPDATECOUNTER:
            /* refresh update counter */
            if( hb_ntxIndexLockRead( pTag->Owner ) )
               hb_ntxIndexUnLockRead( pTag->Owner );
            hb_itemPutNInt( pInfo->itmResult, pTag->Owner->Version );
            break;
         case DBOI_READLOCK:
            if( hb_itemType( pInfo->itmNewVal ) == HB_IT_LOGICAL )
            {
               hb_itemPutL( pInfo->itmResult,
                            hb_itemGetL( pInfo->itmNewVal ) ?
                                 hb_ntxIndexLockRead( pTag->Owner ) :
                                 hb_ntxIndexUnLockRead( pTag->Owner ) );
            }
            else
            {
               hb_itemPutL( pInfo->itmResult, pTag->Owner->lockRead > 0 );
            }
            break;
         case DBOI_WRITELOCK:
            if( hb_itemType( pInfo->itmNewVal ) == HB_IT_LOGICAL )
            {
               hb_itemPutL( pInfo->itmResult,
                            hb_itemGetL( pInfo->itmNewVal ) ?
                                 hb_ntxIndexLockWrite( pTag->Owner, TRUE ) :
                                 hb_ntxIndexUnLockWrite( pTag->Owner ) );
            }
            else
            {
               hb_itemPutL( pInfo->itmResult, pTag->Owner->lockWrite > 0 );
            }
            break;
         case DBOI_ISSORTRECNO:
            hb_itemPutL( pInfo->itmResult, pTag->fSortRec );
            break;
         case DBOI_ISMULTITAG:
#if defined( HB_NTX_NOMULTITAG )
            hb_itemPutL( pInfo->itmResult, FALSE );
#else
            hb_itemPutL( pInfo->itmResult, pTag->Owner->Compound );
#endif
            break;
         case DBOI_LARGEFILE:
            hb_itemPutL( pInfo->itmResult, pTag->Owner->LargeFile );
            break;
         case DBOI_SHARED:
            hb_itemPutL( pInfo->itmResult, pTag->Owner->fShared );
            if( hb_itemType( pInfo->itmNewVal ) == HB_IT_LOGICAL )
               pTag->Owner->fShared = hb_itemGetL( pInfo->itmNewVal );
            break;
         case DBOI_ISREADONLY:
            hb_itemPutL( pInfo->itmResult, pTag->Owner->fReadonly );
            break;
      }
   }
   else if( pInfo->itmResult )
   {
      switch( uiIndex )
      {
         case DBOI_KEYCOUNT:
         {
            ULONG ulRecCount = 0;
            SELF_RECCOUNT( ( AREAP ) pArea, &ulRecCount );
            hb_itemPutNInt( pInfo->itmResult, ulRecCount );
            break;
         }
         case DBOI_POSITION:
            if( pInfo->itmNewVal && hb_itemType( pInfo->itmNewVal ) & HB_IT_NUMERIC )
               hb_itemPutL( pInfo->itmResult, SELF_GOTO( ( AREAP ) pArea,
                              hb_itemGetNL( pInfo->itmNewVal ) ) == SUCCESS );
            else
               SELF_RECID( ( AREAP ) pArea, pInfo->itmResult );
            break;
         case DBOI_RELKEYPOS:
            if( hb_itemType( pInfo->itmNewVal ) & HB_IT_NUMERIC )
            {
               double dPos = hb_itemGetND( pInfo->itmNewVal );
               LPTAGINFO pSavedTag = pArea->lpCurTag;
               pArea->lpCurTag = NULL;
               if( dPos >= 1.0 )
               {
                  SELF_GOBOTTOM( ( AREAP ) pArea );
               }
               else if( dPos <= 0.0 )
               {
                  SELF_GOTOP( ( AREAP ) pArea );
               }
               else
               {
                  ULONG ulRecCount, ulRecNo;
                  SELF_RECCOUNT( ( AREAP ) pArea, &ulRecCount );
                  ulRecNo = ( ULONG ) dPos * ulRecCount + 1;
                  if( ulRecNo >= ulRecCount )
                     ulRecNo = ulRecCount;
                  SELF_GOTO( ( AREAP ) pArea, ulRecNo );
                  SELF_SKIPFILTER( ( AREAP ) pArea, 1 );
                  if( pArea->fEof )
                     SELF_GOTOP( ( AREAP ) pArea );
               }
               pArea->lpCurTag = pSavedTag;
            }
            else
            {
               ULONG ulRecNo = 0, ulRecCount = 0;
               double dPos = 0.0;
               /* resolve any pending relations */
               SELF_RECNO( ( AREAP ) pArea, &ulRecNo );
               if( !pArea->fPositioned )
               {
                  if( ulRecNo > 1 )
                     dPos = 1.0;
               }
               else
               {
                  SELF_RECCOUNT( ( AREAP ) pArea, &ulRecCount );
                  if( ulRecCount != 0 )
                     dPos = ( 0.5 + ulRecNo ) / ulRecCount;
               }
               hb_itemPutND( pInfo->itmResult, dPos );
            }
            break;
         case DBOI_SKIPUNIQUE:
            hb_itemPutL( pInfo->itmResult, SELF_SKIP( ( AREAP ) pArea,
               hb_itemGetNL( pInfo->itmNewVal ) >= 0 ? 1 : -1 ) == SUCCESS );
            break;
         case DBOI_SKIPEVAL:
         case DBOI_SKIPEVALBACK:
         case DBOI_SKIPWILD:
         case DBOI_SKIPWILDBACK:
         case DBOI_SKIPREGEX:
         case DBOI_SKIPREGEXBACK:
         case DBOI_FINDREC:
         case DBOI_FINDRECCONT:
            SELF_GOTO( ( AREAP ) pArea, 0 );
            hb_itemPutL( pInfo->itmResult, FALSE );
            break;
         case DBOI_ISCOND:
         case DBOI_ISDESC:
         case DBOI_UNIQUE:
         case DBOI_CUSTOM:
         case DBOI_KEYADD:
         case DBOI_KEYDELETE:

         case DBOI_ISSORTRECNO:
         case DBOI_ISMULTITAG:
         case DBOI_LARGEFILE:
         case DBOI_TEMPLATE:
         case DBOI_MULTIKEY:
         case DBOI_PARTIAL:
         case DBOI_CHGONLY:
         case DBOI_SHARED:
         case DBOI_ISREADONLY:
         case DBOI_WRITELOCK:
         case DBOI_READLOCK:
            hb_itemPutL( pInfo->itmResult, FALSE );
            break;
         case DBOI_KEYVAL:
         case DBOI_SCOPETOP:
         case DBOI_SCOPEBOTTOM:
         case DBOI_SCOPESET:
         case DBOI_SCOPETOPCLEAR:
         case DBOI_SCOPEBOTTOMCLEAR:
         case DBOI_SCOPECLEAR:
            hb_itemClear( pInfo->itmResult );
            break;
         case DBOI_KEYSIZE:
         case DBOI_KEYDEC:
         case DBOI_NUMBER:
         case DBOI_ORDERCOUNT:
         case DBOI_SCOPEEVAL:
         case DBOI_UPDATECOUNTER:
            hb_itemPutNI( pInfo->itmResult, 0 );
            break;
         case DBOI_FILEHANDLE:
            hb_itemPutNInt( pInfo->itmResult, FS_ERROR );
            break;
         default:
            hb_itemPutC( pInfo->itmResult, "" );
      }
   }
   return SUCCESS;
}

static ERRCODE ntxCountScope( NTXAREAP pArea, void * pPtr, LONG * plRecNo )
{
   HB_TRACE(HB_TR_DEBUG, ("ntxCountScope(%p, %p, %p)", pArea, pPtr, plRecNo));

   if ( pPtr == NULL )
   {
      return SUCCESS;
   }
   return SUPER_COUNTSCOPE( ( AREAP ) pArea, pPtr, plRecNo );
}

static ERRCODE ntxOrderListAdd( NTXAREAP pArea, LPDBORDERINFO pOrderInfo )
{
   USHORT uiFlags;
   FHANDLE hFile;
   char szFileName[ _POSIX_PATH_MAX + 1 ], szTagName[ NTX_MAX_TAGNAME + 1 ];
   LPNTXINDEX pIndex, *pIndexPtr;
   ERRCODE errCode;
   BOOL fRetry, fReadonly, fShared, fProd;

   HB_TRACE(HB_TR_DEBUG, ("ntxOrderListAdd(%p, %p)", pArea, pOrderInfo));

   errCode = SELF_GOCOLD( ( AREAP ) pArea );
   if( errCode != SUCCESS )
      return errCode;

   if( hb_itemGetCLen( pOrderInfo->atomBagName ) == 0 )
      return FAILURE;

   hb_ntxCreateFName( pArea, hb_itemGetCPtr( pOrderInfo->atomBagName ),
                      &fProd, szFileName, szTagName );

/*
   if( ! szTagName[0] )
      return FAILURE;
*/

   pIndex = hb_ntxFindBag( pArea, szFileName );

   if( ! pIndex )
   {
      fReadonly = pArea->fReadonly;
      fShared = pArea->fShared;
      uiFlags = ( fReadonly ? FO_READ : FO_READWRITE ) |
                ( fShared ? FO_DENYNONE : FO_EXCLUSIVE );
      do
      {
         fRetry = FALSE;
         hFile = hb_fsExtOpen( ( BYTE * ) szFileName, NULL, uiFlags |
                               FXO_DEFAULTS | FXO_SHARELOCK | FXO_COPYNAME,
                               NULL, NULL );
         if( hFile == FS_ERROR )
         {
            fRetry = ( hb_ntxErrorRT( pArea, EG_OPEN, EDBF_OPEN_INDEX, szFileName,
                     hb_fsError(), EF_CANRETRY | EF_CANDEFAULT ) == E_RETRY );
         }
      }
      while( fRetry );

      if( hFile == FS_ERROR )
         return FAILURE;

      pIndex = hb_ntxIndexNew( pArea );
      pIndex->IndexName = hb_strdup( szFileName );
      pIndex->fReadonly = fReadonly;
      pIndex->fShared = fShared;
      pIndex->DiskFile = hFile;
      pIndex->Production = fProd;

      pIndexPtr = &pArea->lpIndexes;
      while( *pIndexPtr )
         pIndexPtr = &(*pIndexPtr)->pNext;
      *pIndexPtr = pIndex;

      if( hb_ntxIndexLockRead( pIndex ) )
      {
         errCode = hb_ntxIndexLoad( pIndex, szTagName );
         hb_ntxIndexUnLockRead( pIndex );
      }
      else
         errCode = FAILURE;

      if( errCode != SUCCESS )
      {
         *pIndexPtr = pIndex->pNext;
         hb_ntxIndexFree( pIndex );
         hb_ntxErrorRT( pArea, EG_CORRUPTION, EDBF_CORRUPT, szFileName, 0, 0 );
         return errCode;
      }
      /* hb_ntxSetTagNumbers() */
   }

   if( !pArea->lpCurTag && pIndex->iTags )
   {
      pArea->lpCurTag = pIndex->lpTags[0];
      errCode = SELF_GOTOP( ( AREAP ) pArea );
   }
   return errCode;
}

static ERRCODE ntxOrderListClear( NTXAREAP pArea )
{
   LPNTXINDEX *pIndexPtr, pIndex;

   HB_TRACE(HB_TR_DEBUG, ("ntxOrderListClear(%p)", pArea));

   if( SELF_GOCOLD( ( AREAP ) pArea ) == FAILURE )
      return FAILURE;

   pArea->lpCurTag = NULL;
   pIndexPtr = &pArea->lpIndexes;
   while( *pIndexPtr )
   {
      pIndex = *pIndexPtr;
      if( s_fStruct && pIndex->Production &&
          ( s_fStrictStruct ? pArea->fHasTags : hb_set.HB_SET_AUTOPEN ) )
      {
         pIndexPtr = &pIndex->pNext;
      }
      else
      {
         *pIndexPtr = pIndex->pNext;
         hb_ntxIndexFree( pIndex );
      }
   }
   /* hb_ntxSetTagNumbers() */
   return SUCCESS;
}

static ERRCODE ntxOrderListDelete( NTXAREAP pArea, LPDBORDERINFO pOrderInfo )
{
   char szTagName[ NTX_MAX_TAGNAME + 1 ];
   char szFileName[ _POSIX_PATH_MAX + 1 ];
   LPNTXINDEX pIndex, * pIndexPtr;
   BOOL fProd;

   HB_TRACE(HB_TR_DEBUG, ("ntxOrderListDelete(%p, %p)", pArea, pOrderInfo));

   if( SELF_GOCOLD( ( AREAP ) pArea ) == FAILURE )
      return FAILURE;

   hb_ntxCreateFName( pArea, hb_itemGetCPtr( pOrderInfo->atomBagName ), &fProd,
                      szFileName, szTagName );
   pIndex = hb_ntxFindBag( pArea, szFileName );

   if( pIndex )
   {
      pIndexPtr = &pArea->lpIndexes;
      while( *pIndexPtr )
      {
         if( pIndex == *pIndexPtr )
         {
            *pIndexPtr = pIndex->pNext;
            hb_ntxIndexFree( pIndex );
            /* hb_ntxSetTagNumbers() */
            break;
         }
         pIndexPtr = &(*pIndexPtr)->pNext;
      }
   }
   return SUCCESS;
}

static ERRCODE ntxOrderListFocus( NTXAREAP pArea, LPDBORDERINFO pOrderInfo )
{
   HB_TRACE(HB_TR_DEBUG, ("ntxOrderListFocus(%p, %p)", pArea, pOrderInfo));

   pOrderInfo->itmResult = hb_itemPutC( pOrderInfo->itmResult,
                             pArea->lpCurTag ? pArea->lpCurTag->TagName : "" );

   if( pOrderInfo->itmOrder )
   {
      /* TODO: In Clipper tag is not changed when bad name is given */
      pArea->lpCurTag = hb_ntxFindTag( pArea, pOrderInfo->itmOrder,
                                       pOrderInfo->atomBagName );
   }

   return SUCCESS;
}

static ERRCODE ntxOrderListRebuild( NTXAREAP pArea )
{
   LPTAGINFO pCurrTag;
   LPNTXINDEX pIndex;
   ERRCODE errCode;

   HB_TRACE(HB_TR_DEBUG, ("ntxOrderListRebuild(%p)", pArea));

   errCode = SELF_GOCOLD( ( AREAP ) pArea );
   if( errCode != SUCCESS )
      return errCode;

   if( pArea->fShared )
   {
      hb_ntxErrorRT( pArea, EG_SHARED, EDBF_SHARED, pArea->szDataFileName, 0, 0 );
      return FAILURE;
   }
   if( pArea->fReadonly )
   {
      hb_ntxErrorRT( pArea, EG_READONLY, EDBF_READONLY, pArea->szDataFileName, 0, 0 );
      return FAILURE;
   }

   if( pArea->lpdbPendingRel )
   {
      errCode = SELF_FORCEREL( ( AREAP ) pArea );
      if( errCode != SUCCESS )
         return errCode;
   }
   pCurrTag = pArea->lpCurTag;
   pArea->lpCurTag = NULL;
   pIndex = pArea->lpIndexes;
   while( pIndex && errCode == SUCCESS )
   {
      errCode = hb_ntxReIndex( pIndex );
      pIndex = pIndex->pNext;
   }
   if( errCode == SUCCESS )
   {
      pArea->lpCurTag = pCurrTag;
      errCode = SELF_GOTOP( ( AREAP ) pArea );
   }
   return errCode;
}

static ERRCODE ntxRddInfo( LPRDDNODE pRDD, USHORT uiIndex, ULONG ulConnect, PHB_ITEM pItem )
{
   LPDBFDATA pData;

   HB_TRACE(HB_TR_DEBUG, ("ntxRddInfo(%p, %hu, %lu, %p)", pRDD, uiIndex, ulConnect, pItem));

   pData = ( LPDBFDATA ) pRDD->lpvCargo;

   switch( uiIndex )
   {
      case RDDI_ORDBAGEXT:
      case RDDI_ORDEREXT:
      case RDDI_ORDSTRUCTEXT:
      {
         char * szNew = hb_itemGetCPtr( pItem );

         if( szNew[0] == '.' && szNew[1] )
            szNew = hb_strdup( szNew );
         else
            szNew = NULL;

         hb_itemPutC( pItem, pData->szIndexExt[ 0 ] ? pData->szIndexExt : NTX_INDEXEXT );
         if( szNew )
         {
            hb_strncpy( pData->szIndexExt, szNew, HB_MAX_FILE_EXT );
            hb_xfree( szNew );
         }
         break;
      }

      case RDDI_MULTITAG:
      {
#if defined( HB_NTX_NOMULTITAG )
         hb_itemPutL( pItem, FALSE );
#else
         BOOL fMultiTag = s_fMultiTag;
         if( hb_itemType( pItem ) == HB_IT_LOGICAL )
            s_fMultiTag = hb_itemGetL( pItem );
         hb_itemPutL( pItem, fMultiTag );
#endif
         break;
      }

      case RDDI_SORTRECNO:
      {
         BOOL fSortRecNo = s_fSortRecNo;
         if( hb_itemType( pItem ) == HB_IT_LOGICAL )
            s_fSortRecNo = hb_itemGetL( pItem );
         hb_itemPutL( pItem, fSortRecNo );
         break;
      }

      case RDDI_STRUCTORD:
      {
         BOOL fStruct = s_fStruct;
         if( hb_itemType( pItem ) == HB_IT_LOGICAL )
            s_fStruct = hb_itemGetL( pItem );
         hb_itemPutL( pItem, fStruct );
         break;
      }

      case RDDI_STRICTSTRUCT:
      {
         BOOL fStrictStruct = s_fStrictStruct;
         if( hb_itemType( pItem ) == HB_IT_LOGICAL )
            s_fStrictStruct = hb_itemGetL( pItem );
         hb_itemPutL( pItem, fStrictStruct );
         break;
      }

      case RDDI_MULTIKEY:
      {
         BOOL fMultiKey = s_fMultiKey;
         if( hb_itemType( pItem ) == HB_IT_LOGICAL )
            s_fMultiKey = hb_itemGetL( pItem );
         hb_itemPutL( pItem, fMultiKey );
         break;
      }


      default:
         return SUPER_RDDINFO( pRDD, uiIndex, ulConnect, pItem );

   }

   return SUCCESS;
}

static RDDFUNCS ntxTable = { ntxBof,
                             ntxEof,
                             ntxFound,
                             ( DBENTRYP_V ) ntxGoBottom,
                             ntxGoTo,
                             ntxGoToId,
                             ( DBENTRYP_V ) ntxGoTop,
                             ( DBENTRYP_BIB ) ntxSeek,
                             ntxSkip,
                             ntxSkipFilter,
                             ( DBENTRYP_L ) ntxSkipRaw,
                             ntxAddField,
                             ( DBENTRYP_B ) ntxAppend,
                             ntxCreateFields,
                             ntxDeleteRec,
                             ntxDeleted,
                             ntxFieldCount,
                             ntxFieldDisplay,
                             ntxFieldInfo,
                             ntxFieldName,
                             ( DBENTRYP_V ) ntxFlush,
                             ntxGetRec,
                             ntxGetValue,
                             ntxGetVarLen,
                             ( DBENTRYP_V ) ntxGoCold,
                             ( DBENTRYP_V ) ntxGoHot,
                             ntxPutRec,
                             ntxPutValue,
                             ntxRecall,
                             ntxRecCount,
                             ntxRecInfo,
                             ntxRecNo,
                             ntxRecId,
                             ntxSetFieldsExtent,
                             ntxAlias,
                             ( DBENTRYP_V ) ntxClose,
                             ntxCreate,
                             ntxInfo,
                             ntxNewArea,
                             ( DBENTRYP_VP ) ntxOpen,
                             ntxRelease,
                             ( DBENTRYP_SP ) ntxStructSize,
                             ( DBENTRYP_P ) ntxSysName,
                             ntxEval,
                             ( DBENTRYP_V ) ntxPack,
                             ntPackRec,
                             ntxSort,
                             ntxTrans,
                             ntxTransRec,
                             ( DBENTRYP_V ) ntxZap,
                             ntxchildEnd,
                             ntxchildStart,
                             ntxchildSync,
                             ntxsyncChildren,
                             ntxclearRel,
                             ntxforceRel,
                             ntxrelArea,
                             ntxrelEval,
                             ntxrelText,
                             ntxsetRel,
                             ( DBENTRYP_OI ) ntxOrderListAdd,
                             ( DBENTRYP_V ) ntxOrderListClear,
                             ( DBENTRYP_OI ) ntxOrderListDelete,
                             ( DBENTRYP_OI ) ntxOrderListFocus,
                             ( DBENTRYP_V ) ntxOrderListRebuild,
                             ntxOrderCondition,
                             ( DBENTRYP_VOC ) ntxOrderCreate,
                             ( DBENTRYP_OI ) ntxOrderDestroy,
                             ( DBENTRYP_OII ) ntxOrderInfo,
                             ntxClearFilter,
                             ntxClearLocate,
                             ntxClearScope,
                             ( DBENTRYP_VPLP ) ntxCountScope,
                             ntxFilterText,
                             ntxScopeInfo,
                             ntxSetFilter,
                             ntxSetLocate,
                             ntxSetScope,
                             ntxSkipScope,
                             ntxLocate,
                             ntxCompile,
                             ntxError,
                             ntxEvalBlock,
                             ntxRawLock,
                             ntxLock,
                             ntxUnLock,
                             ntxCloseMemFile,
                             ntxCreateMemFile,
                             ntxGetValueFile,
                             ntxOpenMemFile,
                             ntxPutValueFile,
                             ntxReadDBHeader,
                             ntxWriteDBHeader,
                             ntxInit,
                             ntxExit,
                             ntxDrop,
                             ntxExists,
                             ( DBENTRYP_RSLV ) ntxRddInfo,
                             ntxWhoCares
                           };

HB_FUNC( DBFNTX ) {;}

HB_FUNC( DBFNTX_GETFUNCTABLE )
{
   RDDFUNCS * pTable;
   USHORT * uiCount, uiRddId;

   uiCount = ( USHORT * ) hb_itemGetPtr( hb_param( 1, HB_IT_POINTER ) );
   pTable = ( RDDFUNCS * ) hb_itemGetPtr( hb_param( 2, HB_IT_POINTER ) );
   uiRddId = hb_parni( 4 );

   if( pTable )
   {
      ERRCODE errCode;

      if( uiCount )
         * uiCount = RDDFUNCSCOUNT;
      errCode = hb_rddInherit( pTable, &ntxTable, &ntxSuper, ( BYTE * ) "DBFFPT" );
      if( errCode != SUCCESS )
         errCode = hb_rddInherit( pTable, &ntxTable, &ntxSuper, ( BYTE * ) "DBFDBT" );
      if( errCode != SUCCESS )
         errCode = hb_rddInherit( pTable, &ntxTable, &ntxSuper, ( BYTE * ) "DBF" );
      if( errCode == SUCCESS )
      {
         /*
          * we successfully register our RDD so now we can initialize it
          * You may think that this place is RDD init statement, Druzus
          */
         s_uiRddId = uiRddId;
      }
      hb_retni( errCode );
   }
   else
   {
      hb_retni( FAILURE );
   }
}


#define __PRG_SOURCE__ __FILE__

#ifdef HB_PCODE_VER
#  undef HB_PRG_PCODE_VER
#  define HB_PRG_PCODE_VER HB_PCODE_VER
#endif

HB_FUNC_EXTERN( _DBF );

static void hb_dbfntxRddInit( void * cargo )
{
   HB_SYMBOL_UNUSED( cargo );

   if( hb_rddRegister( "DBF",    RDT_FULL ) <= 1 )
   {
      USHORT usResult;

      hb_rddRegister( "DBFFPT", RDT_FULL );
      usResult = hb_rddRegister( "DBFNTX", RDT_FULL );
      if( usResult <= 1 )
      {
         if( usResult == 0 )
         {
            PHB_ITEM pItem = hb_itemPutNI( NULL, DB_MEMO_DBT );
            SELF_RDDINFO( hb_rddGetNode( s_uiRddId ), RDDI_MEMOTYPE, 0, pItem );
            hb_itemRelease( pItem );
         }
         return;
      }
   }

   hb_errInternal( HB_EI_RDDINVALID, NULL, NULL, NULL );

   /* not executed, only to force DBF RDD linking */
   HB_FUNC_EXEC( _DBF );
}

HB_INIT_SYMBOLS_BEGIN( dbfntx1__InitSymbols )
{ "DBFNTX",              {HB_FS_PUBLIC}, {HB_FUNCNAME( DBFNTX )}, NULL },
{ "DBFNTX_GETFUNCTABLE", {HB_FS_PUBLIC}, {HB_FUNCNAME( DBFNTX_GETFUNCTABLE )}, NULL }
HB_INIT_SYMBOLS_END( dbfntx1__InitSymbols )

HB_CALL_ON_STARTUP_BEGIN( _hb_dbfntx_rdd_init_ )
   hb_vmAtInit( hb_dbfntxRddInit, NULL );
HB_CALL_ON_STARTUP_END( _hb_dbfntx_rdd_init_ )

#if defined(HB_PRAGMA_STARTUP)
#  pragma startup dbfntx1__InitSymbols
#  pragma startup _hb_dbfntx_rdd_init_
#elif defined(HB_MSC_STARTUP)
#  if _MSC_VER >= 1010
#     pragma data_seg( ".CRT$XIY" )
#     pragma comment( linker, "/Merge:.CRT=.data" )
#  else
#     pragma data_seg( "XIY" )
#  endif
   static HB_$INITSYM hb_vm_auto_dbfntx1__InitSymbols = dbfntx1__InitSymbols;
   static HB_$INITSYM hb_vm_auto_dbfntx_rdd_init = _hb_dbfntx_rdd_init_;
#  pragma data_seg()
#endif