/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ /* Read record based on a key */ /* * HA_READ_KEY_EXACT => SEARCH_BIGGER * HA_READ_KEY_OR_NEXT => SEARCH_BIGGER * HA_READ_AFTER_KEY => SEARCH_BIGGER * HA_READ_PREFIX => SEARCH_BIGGER * HA_READ_KEY_OR_PREV => SEARCH_SMALLER * HA_READ_BEFORE_KEY => SEARCH_SMALLER * HA_READ_PREFIX_LAST => SEARCH_SMALLER */ #include "mymrgdef.h" /* todo: we could store some additional info to speedup lookups: column (key, keyseg) can be constant per table it can also be increasing (table1.val > table2.val > ...), or decreasing, <=, >=, etc. SerG */ int myrg_rkey(MYRG_INFO *info,byte *record,int inx, const byte *key, uint key_len, enum ha_rkey_function search_flag) { byte *key_buff; uint pack_key_length; MYRG_TABLE *table; MI_INFO *mi; int err; byte *buf=((search_flag == HA_READ_KEY_EXACT) ? record: 0); LINT_INIT(key_buff); LINT_INIT(pack_key_length); if (_myrg_init_queue(info,inx,search_flag)) return my_errno; for (table=info->open_tables ; table != info->end_table ; table++) { mi=table->table; if (table == info->open_tables) { err=mi_rkey(mi,buf,inx,key,key_len,search_flag); key_buff=(byte*) mi->lastkey+mi->s->base.max_key_length; pack_key_length=mi->last_rkey_length; } else { mi->use_packed_key=1; err=mi_rkey(mi,buf,inx,key_buff,pack_key_length,search_flag); mi->use_packed_key=0; } info->last_used_table=table+1; if (err) { if (err == HA_ERR_KEY_NOT_FOUND) continue; return err; } /* adding to queue */ queue_insert(&(info->by_key),(byte *)table); /* if looking for KEY_EXACT, return first matched now */ if (buf) { info->current_table=table; return 0; } } if (!info->by_key.elements) return HA_ERR_KEY_NOT_FOUND; mi=(info->current_table=(MYRG_TABLE *)queue_top(&(info->by_key)))->table; return mi_rrnd(mi,record,mi->lastpos); }