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by brian
clean slate |
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/* Copyright (C) 2000-2002 MySQL 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
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#include "heapdef.h" |
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/* Read prev record for key */
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int heap_rprev(HP_INFO *info, uchar *record) |
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{
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uchar *pos; |
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HP_SHARE *share=info->s; |
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HP_KEYDEF *keyinfo; |
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DBUG_ENTER("heap_rprev"); |
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if (info->lastinx < 0) |
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DBUG_RETURN(my_errno=HA_ERR_WRONG_INDEX); |
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keyinfo = share->keydef + info->lastinx; |
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if (keyinfo->algorithm == HA_KEY_ALG_BTREE) |
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{
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heap_rb_param custom_arg; |
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if (info->last_pos) |
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pos = tree_search_next(&keyinfo->rb_tree, &info->last_pos, |
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offsetof(TREE_ELEMENT, right), |
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offsetof(TREE_ELEMENT, left)); |
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else
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{
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custom_arg.keyseg = keyinfo->seg; |
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custom_arg.key_length = keyinfo->length; |
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custom_arg.search_flag = SEARCH_SAME; |
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pos = tree_search_key(&keyinfo->rb_tree, info->lastkey, info->parents, |
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&info->last_pos, info->last_find_flag, &custom_arg); |
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}
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if (pos) |
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{
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memcpy(&pos, pos + (*keyinfo->get_key_length)(keyinfo, pos), |
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sizeof(uchar*)); |
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info->current_ptr = pos; |
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}
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else
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{
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my_errno = HA_ERR_KEY_NOT_FOUND; |
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}
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}
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else
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{
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if (info->current_ptr || (info->update & HA_STATE_NEXT_FOUND)) |
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{
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if ((info->update & HA_STATE_DELETED)) |
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pos= hp_search(info, share->keydef + info->lastinx, info->lastkey, 3); |
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else
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pos= hp_search(info, share->keydef + info->lastinx, info->lastkey, 2); |
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}
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else
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{
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pos=0; /* Read next after last */ |
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my_errno=HA_ERR_KEY_NOT_FOUND; |
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}
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}
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if (!pos) |
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{
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info->update=HA_STATE_PREV_FOUND; /* For heap_rprev */ |
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if (my_errno == HA_ERR_KEY_NOT_FOUND) |
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my_errno=HA_ERR_END_OF_FILE; |
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DBUG_RETURN(my_errno); |
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}
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memcpy(record,pos,(size_t) share->reclength); |
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info->update=HA_STATE_AKTIV | HA_STATE_PREV_FOUND; |
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DBUG_RETURN(0); |
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}
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