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https://github.com/MariaDB/server.git
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89 lines
2.5 KiB
C
89 lines
2.5 KiB
C
/* Copyright (C) 2006 MySQL AB & MySQL Finland AB & TCX DataKonsult AB
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; version 2 of the License.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA */
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/* Calculate a checksum for a row */
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#include "maria_def.h"
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/**
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Calculate a checksum for the record
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_ma_checksum()
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@param info Maria handler
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@param record Record
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@note
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To ensure that the checksum is independent of the row format
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we need to always calculate the checksum in the original field order.
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@return checksum
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*/
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ha_checksum _ma_checksum(MARIA_HA *info, const uchar *record)
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{
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ha_checksum crc=0;
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uint i,end;
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MARIA_COLUMNDEF *base_column= info->s->columndef;
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uint16 *column_nr= info->s->column_nr;
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if (info->s->base.null_bytes)
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crc= my_checksum(crc, record, info->s->base.null_bytes);
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for (i= 0, end= info->s->base.fields ; i < end ; i++)
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{
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MARIA_COLUMNDEF *column= base_column + column_nr[i];
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const uchar *pos;
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ulong length;
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if (record[column->null_pos] & column->null_bit)
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continue; /* Null field */
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pos= record + column->offset;
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switch (column->type) {
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case FIELD_BLOB:
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{
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uint blob_size_length= column->length- portable_sizeof_char_ptr;
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length= _ma_calc_blob_length(blob_size_length, pos);
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if (length)
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{
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memcpy((char**) &pos, pos + blob_size_length, sizeof(char*));
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crc= my_checksum(crc, pos, length);
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}
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continue;
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}
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case FIELD_VARCHAR:
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{
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uint pack_length= column->fill_length;
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if (pack_length == 1)
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length= (ulong) *pos;
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else
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length= uint2korr(pos);
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pos+= pack_length; /* Skip length information */
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break;
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}
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default:
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length= column->length;
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break;
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}
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crc= my_checksum(crc, pos, length);
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}
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return crc;
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}
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ha_checksum _ma_static_checksum(MARIA_HA *info, const uchar *pos)
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{
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return my_checksum(0, pos, info->s->base.reclength);
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}
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