/* lzo_util.c -- utilities for the LZO library

   This file is part of the LZO real-time data compression library.

   Copyright (C) 1996-2014 Markus Franz Xaver Johannes Oberhumer

   All Rights Reserved.

   The LZO library 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 of

   the License, or (at your option) any later version.

   The LZO library 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 the LZO library; see the file COPYING.

   If not, write to the Free Software Foundation, Inc.,

   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

   Markus F.X.J. Oberhumer

   <markus@oberhumer.com>

   http://www.oberhumer.com/opensource/lzo/

 */

#include "lzo_conf.h"

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

//

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

/* If you use the LZO library in a product, I would appreciate that you

 * keep this copyright string in the executable of your product.

.*/

static const char __lzo_copyright[] =

#if !defined(__LZO_IN_MINLZO)

    /* save space as some people want a really small decompressor */

    LZO_VERSION_STRING;

#else

    "\r\n\n"

    "LZO data compression library.\n"

    "$Copyright: LZO Copyright (C) 1996-2014 Markus Franz Xaver Johannes Oberhumer\n"

    "<markus@oberhumer.com>\n"

    "http://www.oberhumer.com $\n\n"

    "$Id: LZO version: v" LZO_VERSION_STRING ", " LZO_VERSION_DATE " $\n"

    "$Info: " LZO_INFO_STRING " $\n";

#endif

LZO_PUBLIC(const lzo_bytep)

lzo_copyright(void)

{

    return (const lzo_bytep) __lzo_copyright;

}

LZO_PUBLIC(unsigned)

lzo_version(void)

{

    return LZO_VERSION;

}

LZO_PUBLIC(const char *)

lzo_version_string(void)

{

    return LZO_VERSION_STRING;

}

LZO_PUBLIC(const char *)

lzo_version_date(void)

{

    return LZO_VERSION_DATE;

}

LZO_PUBLIC(const lzo_charp)

_lzo_version_string(void)

{

    return LZO_VERSION_STRING;

}

LZO_PUBLIC(const lzo_charp)

_lzo_version_date(void)

{

    return LZO_VERSION_DATE;

}

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

// adler32 checksum

// adapted from free code by Mark Adler <madler@alumni.caltech.edu>

// see http://www.zlib.org/

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

#define LZO_BASE 65521u /* largest prime smaller than 65536 */

#define LZO_NMAX 5552

/* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */

#define LZO_DO1(buf,i)  s1 += buf[i]; s2 += s1

#define LZO_DO2(buf,i)  LZO_DO1(buf,i); LZO_DO1(buf,i+1)

#define LZO_DO4(buf,i)  LZO_DO2(buf,i); LZO_DO2(buf,i+2)

#define LZO_DO8(buf,i)  LZO_DO4(buf,i); LZO_DO4(buf,i+4)

#define LZO_DO16(buf,i) LZO_DO8(buf,i); LZO_DO8(buf,i+8)

LZO_PUBLIC(lzo_uint32_t)

lzo_adler32(lzo_uint32_t adler, const lzo_bytep buf, lzo_uint len)

{

    lzo_uint32_t s1 = adler & 0xffff;

    lzo_uint32_t s2 = (adler >> 16) & 0xffff;

    unsigned k;

    if (buf == NULL)

        return 1;

    while (len > 0)

    {

        k = len < LZO_NMAX ? (unsigned) len : LZO_NMAX;

        len -= k;

        if (k >= 16) do

        {

            LZO_DO16(buf,0);

            buf += 16;

            k -= 16;

        } while (k >= 16);

        if (k != 0) do

        {

            s1 += *buf++;

            s2 += s1;

        } while (--k > 0);

        s1 %= LZO_BASE;

        s2 %= LZO_BASE;

    }

    return (s2 << 16) | s1;

}

#undef LZO_DO1

#undef LZO_DO2

#undef LZO_DO4

#undef LZO_DO8

#undef LZO_DO16

/*

vi:ts=4:et

*/