FATS - Fast Access Tree System
Inhaltsverzeichnis
Programmierschnittstellen
Turbo C, Borland C, C++ für Windows 3.x


Mit den  FATS-Matchcode Befehlen läßt sich auf einfachste Weise ein Volltext-Index mit dem Inhalt der von Ihnen gewünschten Spalten bzw. Felder einer Datentabelle bzw. -datei erstellen.
Jedes Wort und jede Zahl wird in den Index aufgenommen, es wird eine "invertierte Liste" erstellt.

Dieser Index ermöglicht es FATS, jeden Datensatz durch Angabe beliebiger Begriffe in Sekundenbruchteilen zu finden.

FATS stellt dem Anwendungsprogramm unmittelbar nach der Suche eine Liste aller gefundener Satznummern bzw. Primary-Keys zur Verfügung.

Das nachfolgende C/C++ Beispiel demonstriert die Verwendung der FATS Matchcode-Befehle:

/*
   FATS 02.30
   (c) GCS Software, Udo Gertz 1993-1998

   Test program (Borland C/C++)

   This program needs the extended version of FATS (FATSXWIN.DLL)
 
   Use the logical order of an FATS index file to build
   the matchcode index.

   19-03-2009 U.Gertz
*/ 


#include <stdio.h>
#include <io.h>
#include <fcntl.h>
#include <stdlib.h>
#include <sys\stat.h>
#include <string.h>
#include <windows.h>
#include "FATS.h"



  struct custdat {
      char DELETEDMARK;
      char ID[6];
      char NAME[26];
      char JOB[26];
      char STREET[26];
      char ZIP[6];
      char CITY[21];
  };


  char          szCmnd[512];
  char          szKey[256];
  unsigned int  uErrorcode;
  unsigned long dwRecno;
  void _far *   lpFATSData;

  struct custdat cust;


  /*
     The "Build Matchcode" (MB) command demands an ascending number
     as a "RecNo" argument i.e. the matchcode can not usually be
     indexed in the logical order of an index-key.
   
     This example program uses the flag K#:# ("MC"-command)
     to create the matchcode index in sorted order.
  */ 


int PASCAL WinMain(HANDLE hInstance, HANDLE hPrevInstance,
                   LPSTR  lpszCmndParam, int nCmndShow)
{

  int            hCustomer;
  unsigned long  dwCurRecno;
  unsigned long  dwHitId;
  char           cChar;

  _InitEasyWin();

  printf( "\nThis Test Program was designed for Borland C\n\n" );
  printf( "To compile and link the test program, use the following command:\n\n" );
  printf( "  BCC -2 -ml -O2 -tWS MCSORT.C FATSXWIN.LIB\n\n");
  printf( "\nPlease press the [ENTER] key ...\n\n" );

  cChar = getchar();

  /*
     init FATS data area
  */ 

  lpFATSData = FATSLibInit(0, 2);


  /*
     -------> Activation of Network Operation
   
     FATS is standardly equiped for the network environment.
     Nearly all commands can be executed both in single workstation
     and network environment. With the  "Y" Auto Refresh command you
     determine the behavior of FATS accessing all index files.
     Normally it is sufficient to apply this instruction one time at
     the program start whereby the specified access mode will apply
     to all coming opened files, i.e. they are accessed either with
     network (Y\2) or single workstation access (Y\0).

  */  

  dwRecno = FATSLibCall( "Y\\2", &uErrorcode, szKey, lpFATSData );


  /*
     -------> Open data file
  */ 

  printf( "Opening data file ...\n" );

  hCustomer = open( "CUSTOMER.DAT", O_RDWR );
  setmode( hCustomer, O_BINARY );


  /*
     -------> Opening key file
  */ 

  dwRecno = FATSLibCall( "O\\CUSTOMER.KEY\\2", &uErrorcode, szKey, lpFATSData );

  if ( uErrorcode ) {

    printf( "\n" );
    printf( "Error opening the file CUSTOMER.KEY\n" );
    return ( -1 );
  }


  /*
     ========================================================================
               Creating Matchcode Index
     ========================================================================
  */ 


  /*
     -------> Creating Matchcode Index File
   
     With the command  "MC" Create Matchcode File, the most important
     query facilities are determined already while creating the
     matchcode index file. With the search-group flag ("I#"), several
     logically related data columns can be registered in a common index
     so that a query to this index resp. search group extends automatically
     over all these columns. A matchcode file manages up to 32 search
     groups that can be used for joined queries (using the "AND"-operator).
   
     In this example the following search groups are defined:
   
       Search Group    Fields
   
           I1          NAME
           I2          JOB
           I3          ZIP & CITY
   
     The syntax of the command string:
   
       szCmnd = "MC\{FileName}\{Flags}\{FileNo}\{Col1def}[\{Col2def}]"
   
         FileName   Filename, perhaps with an additional path
                    (i.e. C:/DATA/CUSTOMER.FMS or CUSTOMER.FMS)
   
         Flags      Reserved, not used at the moment
   
         FileNo     File number
   
         Col#def    Definition of data column # (flags, separated by comma).
                    The content of the corresponding data columns is transferred
                    the commands "MB", "MI" and "MD" later in the order determined
                    by this command.
   
                    I#  The content of the data column becomes part of search
                        group #. You can combine several columns into a logical
                        search group (e.g. first name, surname).
   
                    C   The content of the data column is edited for word overall
                        searching, i.e. a search for "motorca" e.g. finds
                        "motorcar" and "motor caravan".
   
                    N   Numbers are handled as words, i.e. during a search
                        according to "150", "12150" e.g. is also found.
   
                  K#:#  This switch activates the management of a primary key
                        for this matchcode index file. The first value after
                        the 'K' is the position of the data column within the
                        key (1 == first part), the second value specifies the
                        length of the data column valid as the key.
   
                    Further adjustments are possible and described in detail
                    in the user manual.

  */  

  printf( "\n" );
  printf( "Creating matchcode index file ...\n" );

  dwRecno = FATSLibCall( "MC\\CUSTSORT.FTS\\\\1\\K1:5\\I1\\I2\\I3", &uErrorcode, szKey, lpFATSData );

  /*
   
     "MC\{Filename}\\{FileNo}\K#:#\I1\I2\I3"
   
     The flag K#:# enables the management of a primary key within
     the matchcode file. FATS normaly only uses the record number
     during the generation of a result set. In specific situations,
     if e.g. the physical record number is not known, or does not
     correspond to the ID specified with the MB-command, the generation
     of a primary key becomes necessary. The browser commands then also
     make in addition to the record- or ID-number this key available via
     the FATSKEY-variable to the application.
   
     With the use of this flag, FATS generates a supplementary file with
     the file extension .FMK which is used for the sequential storage of
     the key.
  */ 

  if ( uErrorcode ) {

    printf( "\nFATS Errorcode: %i (Command: MC)\n", uErrorcode );
    return ( uErrorcode );
  }


  /*
     -------> Insert text into the matchcode index
   
     After the matchcode file was generated, the content of the
     data columns may be with the command  "MB" Build Matchcode
     inserted into the matchcode index. The position of the
     data columns within the command string ("Col#data") corresponds
     to that with the call of command Create Matchcode File ("MC")
     determined definition.
   
     The syntax of the command string:
   
       szCmnd = "MB\{FileNo}\{RecNo}\{Col1data}[\{Col2data}[\{Col3data}]]"
   
         FileNo     File number
   
         RecNo      <> 0 Record- resp. id-number
                    == 0 Stop Build, no more records
   
         Col#data   Content of data column #
   
   
     The following sample program code indexes contents of the
     entire data file within a loop:

  */  

  printf( "\n" );
  printf( "Building matchcode index in sorted order\n" );
  printf( "\nPlease press the [ENTER] key ...\n\n" );

  cChar = getchar();


  dwCurRecno = 0L;
  strcpy( szCmnd, "F\\2\\2" );

  /*
   
  */ 

  for ( ;; ) {

    dwRecno = FATSLibCall( szCmnd, &uErrorcode, szKey, lpFATSData );

    if ( !uErrorcode ) {

      lseek( hCustomer, (dwRecno - 1) * sizeof(cust), SEEK_SET );
      read( hCustomer, &cust, sizeof(cust) );

      dwCurRecno++;

      sprintf( szCmnd, "MB\\1\\%lu\\", dwCurRecno );

      /*
         Add the primary key to the command string
      */ 

      strcat ( szCmnd, cust.ID );

        sprintf( &szCmnd[ strlen(szCmnd) ], "\\%s\\%s\\%s %s",
                 cust.NAME,
                 cust.JOB,
                 cust.ZIP, cust.CITY );
      dwRecno = FATSLibCall( szCmnd, &uErrorcode, szKey, lpFATSData );

      if ( uErrorcode ) {

        /*
           If an error occurred during the execution of the "MB" command,
           the matchcode index file is already closed by FATS.
        */ 

        printf( "FATS Errorcode: %i (Command: MB)\n", uErrorcode );
        break;
      }

      printf( "  %s  --> RecNo %lu\n", cust.NAME, dwCurRecno );

      strcpy( szCmnd, "N\\2" );

    } else {

      /*
         After the last record was inserted the creating process
         has to be terminated with the command "MB\{FileNo}\0".
         Because this command closes the matchcode index file you don't
         have to do a close command.
      */ 

      dwRecno = FATSLibCall( "MB\\1\\0", &uErrorcode, szKey, lpFATSData );
      break;
    }

  }


  /*
     ========================================================================
               Matchcode Search
     ========================================================================
  */ 


  /*
     -------> Open matchcode index file
   
     With the command  "O" Open Indexfile you open an existing
     matchcode index file with the opening flags defined with
     the command  "Y" Auto Refresh. After the file was opened
     it can be accessed under the file number you specified.

  */  

  dwRecno = FATSLibCall( "O\\CUSTSORT.FTS\\1", &uErrorcode, szKey, lpFATSData );


  /*
     -------> Search in Search-Group 1 (NAME)
   
   
  */ 

  printf( "\n" );
  printf( "We now search for all customers with the first name Michael.\n" );
  printf( "\nPlease press the [ENTER] key ...\n\n" );

  cChar = getchar();


  strcpy( szCmnd, "MS\\1\\\\0\\michael" );

  do {

    dwHitId = FATSLibCall( szCmnd, &uErrorcode, szKey, lpFATSData );

    if ( !uErrorcode ) {

      /*
       
      */ 

      sprintf( szCmnd, "S\\1\\2\\%s", szKey );
      dwRecno = FATSLibCall( szCmnd, &uErrorcode, szKey, lpFATSData );

      if ( !uErrorcode ) {

        lseek( hCustomer, (dwRecno - 1) * sizeof(cust), SEEK_SET );
        read( hCustomer, &cust, sizeof(cust) );

        printf( "%s | %s\n%s %s (#%lu)\n\n", cust.NAME, cust.JOB,
                cust.ZIP, cust.CITY, dwRecno );
      }
      sprintf( szCmnd, "MA\\1\\%lu", dwHitId );

    }

  } while ( !uErrorcode );




  /*
     --------> Close all fats files
  */ 

  dwRecno = FATSLibCall( "K", &uErrorcode, szKey, lpFATSData );

  close( hCustomer );


  /*
     free FATS data area
  */ 

  lpFATSData = FATSLibExit( lpFATSData );


  return ( 0 );

}

© 2008  GCS Software, Udo Gertz