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

   1 /* Copyright (c) 2002, 2004-2007 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
  19 int myrg_rnext_same(MYRG_INFO *info, uchar *buf)
  20 {
  21   int err;
  22   MI_INFO *mi;
  23
  24   if (!info->current_table)
  25     return (HA_ERR_KEY_NOT_FOUND);
  26
  27   /* at first, do rnext for the table found before */
  28   if ((err=mi_rnext_same(info->current_table->table,NULL)))
  29   {
  30     if (err == HA_ERR_END_OF_FILE)
  31     {
  32       queue_remove(&(info->by_key),0);
  33       if (!info->by_key.elements)
  34         return HA_ERR_END_OF_FILE;
  35     }
  36     else
  37       return err;
  38   }
  39   else
  40   {
  41     /* Found here, adding to queue */
  42     queue_top(&(info->by_key))=(uchar *)(info->current_table);
  43     queue_replaced(&(info->by_key));
  44   }
  45
  46   /* now, mymerge's read_next is as simple as one queue_top */
  47   mi=(info->current_table=(MYRG_TABLE *)queue_top(&(info->by_key)))->table;
  48   return _myrg_mi_read_record(mi,buf);
  49 }
  50