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myisam/mi_debug.c: ***MISSING WEAVE*** Docs/internals.texi: Added coding guidelines Docs/manual.texi: Changelog update + Win32 -> Windows client/mysql.cc: Changed --no-named-commands to be on by default client/mysqlimport.c: Bug fix include/config-win.h: Update of supported functions include/global.h: Removed compiler warning libmysql/libmysql.c: Fix for Ia64 myisam/ChangeLog: Changelog myisam/Makefile.am: Added file mi_dbug.c myisam/ft_stopwords.c: Fix for Ia64 myisam/mi_delete_table.c: Extra debugging myisam/mi_rename.c: Extra debugging myisam/mi_rnext.c: Fixed bug with MIN and concurrent insert myisam/mi_rprev.c: Fixed bug with MAX and concurrent insert myisam/mi_search.c: Fixed bug with DECIMAL/NUMERIC keys myisam/myisamdef.h: Extra debugging scripts/make_binary_distribution.sh: Added thread safe mysql library sql/ha_heap.cc: Fix of HEAP bug with range keys sql/ha_heap.h: Fix of HEAP bug with range keys sql/handler.cc: Optimizing sql/handler.h: Optimizing sql/lock.cc: More DEBUG + fix of RENAME bug sql/mini_client.cc: Fix for Ia64 sql/mysql_priv.h: Fix for name locks sql/mysqld.cc: Shorter message if wrong options sql/opt_range.cc: Added TODO sql/sql_base.cc: Fix for DROP TABLE sql/sql_parse.cc: Fix of permission checking for CHECK TABLE sql/sql_select.cc: Fix of using LEFT JOIN with empty table sql/table.h: Fix for name locks tests/fork_test.pl: Fixed typo
86 lines
2.8 KiB
C
86 lines
2.8 KiB
C
/* Copyright (C) 2000 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; either version 2 of the License, or
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(at your option) any later version.
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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 "myisamdef.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 mi_rprev(MI_INFO *info, byte *buf, int inx)
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{
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int error;
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register uint flag;
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MYISAM_SHARE *share=info->s;
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DBUG_ENTER("mi_rprev");
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if ((inx = _mi_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->lastpos == HA_OFFSET_ERROR && info->update & HA_STATE_NEXT_FOUND)
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flag=0; /* Read last */
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if (_mi_readinfo(info,F_RDLCK,1))
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DBUG_RETURN(my_errno);
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if (share->concurrent_insert)
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rw_rdlock(&share->key_root_lock[inx]);
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if (!flag)
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error=_mi_search_last(info, share->keyinfo+inx,
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share->state.key_root[inx]);
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else if (_mi_test_if_changed(info) == 0)
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error=_mi_search_next(info,share->keyinfo+inx,info->lastkey,
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info->lastkey_length,flag,
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share->state.key_root[inx]);
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else
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error=_mi_search(info,share->keyinfo+inx,info->lastkey,
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info->lastkey_length, flag, share->state.key_root[inx]);
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if (!error)
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{
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while (info->lastpos > info->state->data_file_length)
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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=_mi_search_next(info,share->keyinfo+inx,info->lastkey,
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info->lastkey_length,
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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->concurrent_insert)
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rw_unlock(&share->key_root_lock[inx]);
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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)
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{
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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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DBUG_RETURN(info->lastpos==HA_OFFSET_ERROR ? my_errno : 0);
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}
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else if (!(*info->read_record)(info,info->lastpos,buf))
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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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} /* mi_rprev */
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