/* 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 */ #include "myisamdef.h" #include "rt_index.h" /* Read next row with the same key as previous read, but abort if the key changes. One may have done a write, update or delete of the previous row. NOTE! Even if one changes the previous row, the next read is done based on the position of the last used key! */ int mi_rnext_same(MI_INFO *info, byte *buf) { int error; uint inx,not_used; MI_KEYDEF *keyinfo; DBUG_ENTER("mi_rnext_same"); if ((int) (inx=info->lastinx) < 0 || info->lastpos == HA_OFFSET_ERROR) DBUG_RETURN(my_errno=HA_ERR_WRONG_INDEX); keyinfo=info->s->keyinfo+inx; if (fast_mi_readinfo(info)) DBUG_RETURN(my_errno); if (info->s->concurrent_insert) rw_rdlock(&info->s->key_root_lock[inx]); switch (keyinfo->key_alg) { #ifdef HAVE_RTREE_KEYS case HA_KEY_ALG_RTREE: if ((error=rtree_find_next(info,inx, myisam_read_vec[info->last_key_func]))) { error=1; my_errno=HA_ERR_END_OF_FILE; info->lastpos= HA_OFFSET_ERROR; break; } break; #endif case HA_KEY_ALG_BTREE: default: if (!(info->update & HA_STATE_RNEXT_SAME)) { /* First rnext_same; Store old key */ memcpy(info->lastkey2,info->lastkey,info->last_rkey_length); } for (;;) { if ((error=_mi_search_next(info,keyinfo,info->lastkey, info->lastkey_length,SEARCH_BIGGER, info->s->state.key_root[inx]))) break; if (ha_key_cmp(keyinfo->seg,info->lastkey2,info->lastkey, info->last_rkey_length, SEARCH_FIND, ¬_used)) { error=1; my_errno=HA_ERR_END_OF_FILE; info->lastpos= HA_OFFSET_ERROR; break; } /* Skip rows that are inserted by other threads since we got a lock */ if (info->lastpos < info->state->data_file_length) break; } } if (info->s->concurrent_insert) rw_unlock(&info->s->key_root_lock[inx]); /* Don't clear if database-changed */ info->update&= (HA_STATE_CHANGED | HA_STATE_ROW_CHANGED); info->update|= HA_STATE_NEXT_FOUND | HA_STATE_RNEXT_SAME; if (error) { if (my_errno == HA_ERR_KEY_NOT_FOUND) my_errno=HA_ERR_END_OF_FILE; } else if (!buf) { DBUG_RETURN(info->lastpos==HA_OFFSET_ERROR ? my_errno : 0); } else if (!(*info->read_record)(info,info->lastpos,buf)) { info->update|= HA_STATE_AKTIV; /* Record is read */ DBUG_RETURN(0); } DBUG_RETURN(my_errno); } /* mi_rnext */