mirror of
https://github.com/MariaDB/server.git
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120 lines
3.8 KiB
C
120 lines
3.8 KiB
C
/* Copyright (C) 2006 MySQL AB & MySQL Finland AB & TCX DataKonsult 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA */
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#include "maria_def.h"
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#include "ma_rt_index.h"
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/*
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Read next row with the same key as previous read, but abort if
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the key changes.
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One may have done a write, update or delete of the previous row.
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NOTE! Even if one changes the previous row, the next read is done
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based on the position of the last used key!
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*/
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int maria_rnext_same(MARIA_HA *info, uchar *buf)
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{
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int error;
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uint inx,not_used[2];
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MARIA_KEYDEF *keyinfo;
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check_result_t check= CHECK_POS;
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DBUG_ENTER("maria_rnext_same");
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if ((int) (inx= info->lastinx) < 0 ||
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info->cur_row.lastpos == HA_OFFSET_ERROR)
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DBUG_RETURN(my_errno=HA_ERR_WRONG_INDEX);
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if (fast_ma_readinfo(info))
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DBUG_RETURN(my_errno);
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keyinfo= info->s->keyinfo+inx;
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if (info->s->lock_key_trees)
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mysql_rwlock_rdlock(&keyinfo->root_lock);
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switch (keyinfo->key_alg) {
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case HA_KEY_ALG_RTREE:
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if ((error=maria_rtree_find_next(info,inx,
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maria_read_vec[info->last_key_func])))
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{
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error=1;
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my_errno=HA_ERR_END_OF_FILE;
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info->cur_row.lastpos= HA_OFFSET_ERROR;
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break;
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}
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break;
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case HA_KEY_ALG_BTREE:
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default:
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if (!(info->update & HA_STATE_RNEXT_SAME))
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{
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/* First rnext_same; Store old key */
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memcpy(info->lastkey_buff2, info->last_key.data,
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info->last_rkey_length);
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}
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for (;;)
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{
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if ((error= _ma_search_next(info, &info->last_key,
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SEARCH_BIGGER,
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info->s->state.key_root[inx])))
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break;
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if (ha_key_cmp(keyinfo->seg, info->last_key.data,
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info->lastkey_buff2,
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info->last_rkey_length, SEARCH_FIND,
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not_used))
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{
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error=1;
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my_errno=HA_ERR_END_OF_FILE;
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info->cur_row.lastpos= HA_OFFSET_ERROR;
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break;
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}
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/*
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If we are at the last key on the key page, allow writers to
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access the index.
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*/
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if (info->int_keypos >= info->int_maxpos &&
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ma_yield_and_check_if_killed(info, inx))
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{
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error= 1;
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break;
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}
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/* Skip rows that are inserted by other threads since we got a lock */
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if ((info->s->row_is_visible)(info) &&
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((check= ma_check_index_cond(info, inx, buf)) != CHECK_NEG))
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break;
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}
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}
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if (info->s->lock_key_trees)
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mysql_rwlock_unlock(&keyinfo->root_lock);
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/* Don't clear if database-changed */
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info->update&= (HA_STATE_CHANGED | HA_STATE_ROW_CHANGED);
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info->update|= HA_STATE_NEXT_FOUND | HA_STATE_RNEXT_SAME;
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if (error || check != CHECK_POS)
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{
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fast_ma_writeinfo(info);
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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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}
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else if (!buf)
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{
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fast_ma_writeinfo(info);
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DBUG_RETURN(info->cur_row.lastpos == HA_OFFSET_ERROR ? my_errno : 0);
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}
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else if (!(*info->read_record)(info, buf, info->cur_row.lastpos))
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{
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info->update|= HA_STATE_AKTIV; /* Record is read */
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DBUG_RETURN(0);
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}
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DBUG_RETURN(my_errno);
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} /* maria_rnext_same */
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