mirror of
https://github.com/MariaDB/server.git
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17b4f99928
This commit is based on the work of Michal Schorm, rebased on the
earliest MariaDB version.
Th command line used to generate this diff was:
find ./ -type f \
-exec sed -i -e 's/Foundation, Inc., 59 Temple Place, Suite 330, Boston, /Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, /g' {} \; \
-exec sed -i -e 's/Foundation, Inc. 59 Temple Place.* Suite 330, Boston, /Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, /g' {} \; \
-exec sed -i -e 's/MA.*.....-1307.*USA/MA 02110-1335 USA/g' {} \; \
-exec sed -i -e 's/Foundation, Inc., 59 Temple/Foundation, Inc., 51 Franklin/g' {} \; \
-exec sed -i -e 's/Place, Suite 330, Boston, MA.*02111-1307.*USA/Street, Fifth Floor, Boston, MA 02110-1335 USA/g' {} \; \
-exec sed -i -e 's/MA.*.....-1307/MA 02110-1335/g' {} \;
106 lines
3.5 KiB
C
106 lines
3.5 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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/*
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Read previous row with the same key as previous read
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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_rprev(MARIA_HA *info, uchar *buf, int inx)
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{
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int error,changed;
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register uint flag;
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MARIA_SHARE *share= info->s;
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MARIA_KEYDEF *keyinfo;
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ICP_RESULT icp_res= ICP_MATCH;
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DBUG_ENTER("maria_rprev");
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if ((inx = _ma_check_index(info,inx)) < 0)
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DBUG_RETURN(my_errno);
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flag=SEARCH_SMALLER; /* Read previous */
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if (info->cur_row.lastpos == HA_OFFSET_ERROR &&
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info->update & HA_STATE_NEXT_FOUND)
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flag=0; /* Read last */
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if (fast_ma_readinfo(info))
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DBUG_RETURN(my_errno);
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keyinfo= share->keyinfo + inx;
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changed= _ma_test_if_changed(info);
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if (share->lock_key_trees)
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mysql_rwlock_rdlock(&keyinfo->root_lock);
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if (!flag)
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error= _ma_search_last(info, keyinfo, share->state.key_root[inx]);
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else if (!changed)
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error= _ma_search_next(info, &info->last_key,
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flag | info->last_key.flag,
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share->state.key_root[inx]);
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else
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error= _ma_search(info, &info->last_key, flag | info->last_key.flag,
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share->state.key_root[inx]);
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if (!error)
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{
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my_off_t cur_keypage= info->last_keypage;
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while (!(*share->row_is_visible)(info) ||
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((icp_res= ma_check_index_cond(info, inx, buf)) == ICP_NO_MATCH))
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{
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/*
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If we are at the last (i.e. first?) key on the key page,
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allow writers to access the index.
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*/
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if (info->last_keypage != cur_keypage)
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{
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cur_keypage= info->last_keypage;
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if (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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}
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/* Skip rows that are inserted by other threads since we got a lock */
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if ((error= _ma_search_next(info, &info->last_key,
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SEARCH_SMALLER,
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share->state.key_root[inx])))
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break;
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}
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}
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if (share->lock_key_trees)
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mysql_rwlock_unlock(&keyinfo->root_lock);
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info->update&= (HA_STATE_CHANGED | HA_STATE_ROW_CHANGED);
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info->update|= HA_STATE_PREV_FOUND;
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if (error || icp_res != ICP_MATCH)
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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_rprev */
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