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https://github.com/MariaDB/server.git
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88 lines
2.6 KiB
C
88 lines
2.6 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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/* Read record based on a key */
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/*
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* HA_READ_KEY_EXACT => SEARCH_BIGGER
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* HA_READ_KEY_OR_NEXT => SEARCH_BIGGER
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* HA_READ_AFTER_KEY => SEARCH_BIGGER
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* HA_READ_PREFIX => SEARCH_BIGGER
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* HA_READ_KEY_OR_PREV => SEARCH_SMALLER
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* HA_READ_BEFORE_KEY => SEARCH_SMALLER
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* HA_READ_PREFIX_LAST => SEARCH_SMALLER
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*/
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#include "myrg_def.h"
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/* todo: we could store some additional info to speedup lookups:
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column (key, keyseg) can be constant per table
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it can also be increasing (table1.val > table2.val > ...),
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or decreasing, <=, >=, etc.
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SerG
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*/
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int myrg_rkey(MYRG_INFO *info,byte *buf,int inx, const byte *key,
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uint key_len, enum ha_rkey_function search_flag)
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{
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byte *key_buff;
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uint pack_key_length;
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MYRG_TABLE *table;
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MI_INFO *mi;
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int err;
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LINT_INIT(key_buff);
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LINT_INIT(pack_key_length);
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if (_myrg_init_queue(info,inx,search_flag))
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return my_errno;
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for (table=info->open_tables ; table != info->end_table ; table++)
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{
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mi=table->table;
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if (table == info->open_tables)
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{
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err=mi_rkey(mi,0,inx,key,key_len,search_flag);
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key_buff=(byte*) mi->lastkey+mi->s->base.max_key_length;
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pack_key_length=mi->last_rkey_length;
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}
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else
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{
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mi->once_flags|= USE_PACKED_KEYS;
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err=mi_rkey(mi,0,inx,key_buff,pack_key_length,search_flag);
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}
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info->last_used_table=table+1;
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if (err)
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{
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if (err == HA_ERR_KEY_NOT_FOUND)
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continue;
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return err;
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}
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/* adding to queue */
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queue_insert(&(info->by_key),(byte *)table);
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}
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if (!info->by_key.elements)
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return HA_ERR_KEY_NOT_FOUND;
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mi=(info->current_table=(MYRG_TABLE *)queue_top(&(info->by_key)))->table;
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mi->once_flags|= RRND_PRESERVE_LASTINX;
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return _myrg_mi_read_record(mi,buf);
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}
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