release/src/router/mysql/storage/myisammrg/myrg_rlast.c

   1 /* Copyright (c) 2000, 2001, 2003, 2005-2007 MySQL AB
   2
   3    This program is free software; you can redistribute it and/or modify
   4    it under the terms of the GNU General Public License as published by
   5    the Free Software Foundation; version 2 of the License.
   6
   7    This program is distributed in the hope that it will be useful,
   8    but WITHOUT ANY WARRANTY; without even the implied warranty of
   9    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  10    GNU General Public License for more details.
  11
  12    You should have received a copy of the GNU General Public License
  13    along with this program; if not, write to the Free Software
  14    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA */
  15
  16 #include "myrg_def.h"
  17
  18         /* Read last row with the same key as the previous read. */
  19
  20 int myrg_rlast(MYRG_INFO *info, uchar *buf, int inx)
  21 {
  22   MYRG_TABLE *table;
  23   MI_INFO *mi;
  24   int err;
  25
  26   if (_myrg_init_queue(info,inx, HA_READ_KEY_OR_PREV))
  27     return my_errno;
  28
  29   for (table=info->open_tables ; table < info->end_table ; table++)
  30   {
  31     if ((err=mi_rlast(table->table,NULL,inx)))
  32     {
  33       if (err == HA_ERR_END_OF_FILE)
  34         continue;
  35       return err;
  36     }
  37     /* adding to queue */
  38     queue_insert(&(info->by_key),(uchar *)table);
  39   }
  40   /* We have done a read in all tables */
  41   info->last_used_table=table;
  42
  43   if (!info->by_key.elements)
  44     return HA_ERR_END_OF_FILE;
  45
  46   mi=(info->current_table=(MYRG_TABLE *)queue_top(&(info->by_key)))->table;
  47   return _myrg_mi_read_record(mi,buf);
  48 }
  49