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/* Copyright (C) 2000 MySQL AB
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 of the License, 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 program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
#include <my_global.h>
#include "my_sys.h"
/*
Calculate a long checksum for a memoryblock. Used to verify pack_isam
SYNOPSIS
checksum()
mem Pointer to memory block
count Count of bytes
*/
ulong checksum(const byte *mem, uint count)
{
ulong crc;
for (crc= 0; count-- ; mem++)
crc= ((crc << 1) + *((uchar*) mem)) +
test(crc & ((ulong) 1L << (8*sizeof(ulong)-1)));
return crc;
}
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