Files
harbour-core/harbour/source/rtl/hbadler.c
Przemyslaw Czerpak 96561eeae0 2007-03-31 12:40 UTC+0200 Przemyslaw Czerpak (druzus/at/priv.onet.pl)
* harbour/include/Makefile
  + harbour/include/hbchksum.h
  * harbour/source/rtl/Makefile
  + harbour/source/rtl/hbadler.c
  + harbour/source/rtl/hbcrc.c
  + harbour/source/rtl/hbmd5.c
    + added functions to calculate different checksums
         HB_ADLER( <cValue> [, <nStart> ] ) -> <nCC>
         HB_CRC32( <cValue> [, <nStart> ] ) -> <nCRC>
         HB_CRC16( <cValue> [, <nStart> ] ) -> <nCRC>
         HB_CRC  ( <cValue> [, <nStart> ] [, <nPolynomial> ] ) -> <nCRC>
         HB_CRCCT( <cValue> [, <nStart> ] [, <nPolynomial> ] ) -> <nCRC>
         HB_MD5( <cString> ) -> <cMD5>
         HB_MD5FILE( <cFileName> ) -> <cMD5>
      HB_CRC() is general CRC function which can be used for any polynomial
      given as second argument, f.e.: 0x104C11DB7 is CRC32 polynomial,
      0x18005 -> CRC16, 0x11021 -> CRC16 X.26, 0x1393 -> CRC12, 0x101 -> LCR8
      HB_CRCCT() makes exactly the same job but it uses broken algorithm.
      Unfortunately it seems that this broken version is widely used by many
      other projects, f.e. HB_CRCCT() gives exactly the same results as
      COM_CRC() from CT3. Generated results are usually "good enough" but
      if you do not need compatibility with some other tools which uses
      broken CRC algorithm then I suggest to not use it.
      HB_ADLER() is ADLER32 check sum - this function gives the same results
      as HB_CHECKSUM in xHarbour.
      HB_MD5*() functions are from Dmitry V. Korzhov code modified a
      little bit by me for other then x86@32 machines files and buffers
      longer then 2^32. I also fixed possible problems with wrong results
      in some cases.

  * harbour/source/compiler/hbmain.c
    * increase number of optimization passes

  * harbour/source/pp/ppcore.c
    * cleaned C compiler warning
2007-03-31 10:42:19 +00:00

97 lines
3.2 KiB
C

/*
* $Id$
*/
/*
* Harbour Project source code:
* adler32 checksum function
*
* Copyright 2007 Przemyslaw Czerpak <druzus / at / priv.onet.pl>
* www - http://www.harbour-project.org
*
* Algorithm taken from adler32.c Copyright (C) 1995-2002 Mark Adler
*
* 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.
*
*/
#include "hbapi.h"
#include "hbapierr.h"
#include "hbchksum.h"
#define BASE 65521 /* largest prime smaller than 65536 */
#define NMAX 5552 /* largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */
HB_EXPORT ULONG hb_adler32( ULONG adler, const BYTE *buf, ULONG len )
{
ULONG s1 = adler & 0xffff;
ULONG s2 = ( adler >> 16 ) & 0xffff;
if( buf && len )
{
do
{
int i = len < NMAX ? len : NMAX;
len -= i;
do
{
s1 += ( UCHAR ) *buf++;
s2 += s1;
}
while( --i );
s1 %= BASE;
s2 %= BASE;
}
while( len );
}
return ( s2 << 16 ) | s1;
}
HB_FUNC( HB_ADLER32 )
{
char * szString = hb_parc( 1 );
if( szString )
hb_retnint( hb_adler32( ( ULONG ) hb_parnl( 2 ), ( BYTE * ) szString, hb_parclen( 1 ) ) );
else
hb_errRT_BASE( EG_ARG, 3012, NULL, &hb_errFuncName, HB_ERR_ARGS_BASEPARAMS );
}