mirror of
https://github.com/MariaDB/server.git
synced 2025-01-16 20:12:31 +01:00
89 lines
2.5 KiB
C
89 lines
2.5 KiB
C
/* Copyright (C) 2006 MySQL AB & MySQL Finland AB & TCX DataKonsult 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; 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 02110-1335 USA */
|
|
|
|
/* Calculate a checksum for a row */
|
|
|
|
#include "maria_def.h"
|
|
|
|
/**
|
|
Calculate a checksum for the record
|
|
|
|
_ma_checksum()
|
|
@param info Maria handler
|
|
@param record Record
|
|
|
|
@note
|
|
To ensure that the checksum is independent of the row format
|
|
we need to always calculate the checksum in the original field order.
|
|
|
|
@return checksum
|
|
*/
|
|
|
|
ha_checksum _ma_checksum(MARIA_HA *info, const uchar *record)
|
|
{
|
|
ha_checksum crc=0;
|
|
uint i,end;
|
|
MARIA_COLUMNDEF *base_column= info->s->columndef;
|
|
uint16 *column_nr= info->s->column_nr;
|
|
|
|
if (info->s->base.null_bytes)
|
|
crc= my_checksum(crc, record, info->s->base.null_bytes);
|
|
|
|
for (i= 0, end= info->s->base.fields ; i < end ; i++)
|
|
{
|
|
MARIA_COLUMNDEF *column= base_column + column_nr[i];
|
|
const uchar *pos;
|
|
ulong length;
|
|
|
|
if (record[column->null_pos] & column->null_bit)
|
|
continue; /* Null field */
|
|
|
|
pos= record + column->offset;
|
|
switch (column->type) {
|
|
case FIELD_BLOB:
|
|
{
|
|
uint blob_size_length= column->length- portable_sizeof_char_ptr;
|
|
length= _ma_calc_blob_length(blob_size_length, pos);
|
|
if (length)
|
|
{
|
|
memcpy((char**) &pos, pos + blob_size_length, sizeof(char*));
|
|
crc= my_checksum(crc, pos, length);
|
|
}
|
|
continue;
|
|
}
|
|
case FIELD_VARCHAR:
|
|
{
|
|
uint pack_length= column->fill_length;
|
|
if (pack_length == 1)
|
|
length= (ulong) *pos;
|
|
else
|
|
length= uint2korr(pos);
|
|
pos+= pack_length; /* Skip length information */
|
|
break;
|
|
}
|
|
default:
|
|
length= column->length;
|
|
break;
|
|
}
|
|
crc= my_checksum(crc, pos, length);
|
|
}
|
|
return crc;
|
|
}
|
|
|
|
|
|
ha_checksum _ma_static_checksum(MARIA_HA *info, const uchar *pos)
|
|
{
|
|
return my_checksum(0, pos, info->s->base.reclength);
|
|
}
|