hp_rnext.c 2.63 KB
Newer Older
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1
/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB
monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
2

bk@work.mysql.com's avatar
bk@work.mysql.com committed
3 4 5 6
   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; either version 2 of the License, or
   (at your option) any later version.
monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
7

bk@work.mysql.com's avatar
bk@work.mysql.com committed
8 9 10 11
   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.
monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
12

bk@work.mysql.com's avatar
bk@work.mysql.com committed
13 14 15 16 17 18 19 20 21 22 23 24
   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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */

#include "heapdef.h"

/* Read next record with the same key */

int heap_rnext(HP_INFO *info, byte *record)
{
  byte *pos;
  HP_SHARE *share=info->s;
25
  HP_KEYDEF *keyinfo;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
26
  DBUG_ENTER("heap_rnext");
27
  
bk@work.mysql.com's avatar
bk@work.mysql.com committed
28 29 30
  if (info->lastinx < 0)
    DBUG_RETURN(my_errno=HA_ERR_WRONG_INDEX);

31 32
  keyinfo = share->keydef + info->lastinx;
  if (keyinfo->algorithm == HA_KEY_ALG_BTREE)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
33
  {
34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53
    heap_rb_param custom_arg;

    if (info->last_pos)
      pos = tree_search_next(&keyinfo->rb_tree, &info->last_pos,
                             offsetof(TREE_ELEMENT, left),
                             offsetof(TREE_ELEMENT, right));
    else
    {
      custom_arg.keyseg = keyinfo->seg;
      custom_arg.key_length = info->lastkey_len;
      custom_arg.search_flag = SEARCH_SAME | SEARCH_FIND;
      pos = tree_search_key(&keyinfo->rb_tree, info->lastkey, info->parents, 
                           &info->last_pos, info->last_find_flag, &custom_arg);
    }
    if (pos)
    {
      memcpy(&pos, pos + keyinfo->ref_offs, sizeof(byte*));
      info->current_ptr = pos;
    }
    else
bk@work.mysql.com's avatar
bk@work.mysql.com committed
54
    {
55
      my_errno = HA_ERR_KEY_NOT_FOUND;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
56
    }
57 58 59 60 61 62
  }
  else
  {
    if (info->current_hash_ptr)
      pos= hp_search_next(info, keyinfo, info->lastkey,
			   info->current_hash_ptr);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
63
    else
64 65 66 67 68 69 70 71 72 73 74
    {
      if (!info->current_ptr && (info->update & HA_STATE_NEXT_FOUND))
      {
	pos=0;					/* Read next after last */
	my_errno=HA_ERR_KEY_NOT_FOUND;
      }
      else if (!info->current_ptr)		/* Deleted or first call */
	pos= hp_search(info, keyinfo, info->lastkey, 0);
      else
	pos= hp_search(info, keyinfo, info->lastkey, 1);
    }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
75 76 77 78 79 80 81 82 83 84 85 86
  }
  if (!pos)
  {
    info->update=HA_STATE_NEXT_FOUND;		/* For heap_rprev */
    if (my_errno == HA_ERR_KEY_NOT_FOUND)
      my_errno=HA_ERR_END_OF_FILE;
    DBUG_RETURN(my_errno);
  }
  memcpy(record,pos,(size_t) share->reclength);
  info->update=HA_STATE_AKTIV | HA_STATE_NEXT_FOUND;
  DBUG_RETURN(0);
}