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/* Copyright (c) 2000-2003, 2005-2007 MySQL AB
Use is subject to license terms
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 */
#include "myrg_def.h"
/*
Read previous row with the same key as previous read
*/
int myrg_rprev(MYRG_INFO *info, uchar *buf, int inx)
{
int err;
MI_INFO *mi;
if (!info->current_table)
return (HA_ERR_KEY_NOT_FOUND);
/* at first, do rprev for the table found before */
if ((err=mi_rprev(info->current_table->table,NULL,inx)))
{
if (err == HA_ERR_END_OF_FILE)
{
queue_remove_top(&(info->by_key));
if (!info->by_key.elements)
return HA_ERR_END_OF_FILE;
}
else
return err;
}
else
{
/* Found here, adding to queue */
queue_top(&(info->by_key))=(uchar *)(info->current_table);
queue_replace_top(&(info->by_key));
}
/* now, mymerge's read_prev is as simple as one queue_top */
mi=(info->current_table=(MYRG_TABLE *)queue_top(&(info->by_key)))->table;
return _myrg_mi_read_record(mi,buf);
}
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