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53 lines
1.6 KiB
C
53 lines
1.6 KiB
C
/* Copyright (c) 2000-2003, 2005-2007 MySQL AB
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Use is subject to license terms
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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 "myrg_def.h"
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/*
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Read previous row with the same key as previous read
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*/
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int myrg_rprev(MYRG_INFO *info, uchar *buf, int inx)
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{
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int err;
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MI_INFO *mi;
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if (!info->current_table)
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return (HA_ERR_KEY_NOT_FOUND);
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/* at first, do rprev for the table found before */
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if ((err=mi_rprev(info->current_table->table,NULL,inx)))
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{
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if (err == HA_ERR_END_OF_FILE)
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{
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queue_remove_top(&(info->by_key));
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if (!info->by_key.elements)
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return HA_ERR_END_OF_FILE;
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}
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else
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return err;
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}
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else
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{
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/* Found here, adding to queue */
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queue_top(&(info->by_key))=(uchar *)(info->current_table);
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queue_replace_top(&(info->by_key));
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}
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/* now, mymerge's read_prev is as simple as one queue_top */
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mi=(info->current_table=(MYRG_TABLE *)queue_top(&(info->by_key)))->table;
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return _myrg_mi_read_record(mi,buf);
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}
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