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/* Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
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; version 2 of the License.
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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA */
/* Calculate a checksum for a row */
#include "myisamdef.h"
ha_checksum mi_checksum(MI_INFO *info, const uchar *buf)
{
uint i;
ha_checksum crc=0;
MI_COLUMNDEF *rec=info->s->rec;
for (i=info->s->base.fields ; i-- ; buf+=(rec++)->length)
{
const uchar *pos;
ulong length;
switch (rec->type) {
case FIELD_BLOB:
{
length=_mi_calc_blob_length(rec->length-
portable_sizeof_char_ptr,
buf);
memcpy(&pos, buf+rec->length- portable_sizeof_char_ptr, sizeof(char*));
break;
}
case FIELD_VARCHAR:
{
uint pack_length= HA_VARCHAR_PACKLENGTH(rec->length-1);
if (pack_length == 1)
length= (ulong) *(uchar*) buf;
else
length= uint2korr(buf);
pos= buf+pack_length;
break;
}
default:
length=rec->length;
pos=buf;
break;
}
crc=my_checksum(crc, pos ? pos : (uchar*) "", length);
}
return crc;
}
ha_checksum mi_static_checksum(MI_INFO *info, const uchar *pos)
{
return my_checksum(0, pos, info->s->base.reclength);
}
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