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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 18:07:14 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 18:07:14 +0000 |
commit | a175314c3e5827eb193872241446f2f8f5c9d33c (patch) | |
tree | cd3d60ca99ae00829c52a6ca79150a5b6e62528b /storage/heap/hp_rprev.c | |
parent | Initial commit. (diff) | |
download | mariadb-10.5-9e4947182e0b875da38088fdd168e775f473b8ad.tar.xz mariadb-10.5-9e4947182e0b875da38088fdd168e775f473b8ad.zip |
Adding upstream version 1:10.5.12.upstream/1%10.5.12upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'storage/heap/hp_rprev.c')
-rw-r--r-- | storage/heap/hp_rprev.c | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/storage/heap/hp_rprev.c b/storage/heap/hp_rprev.c new file mode 100644 index 00000000..1d9420ba --- /dev/null +++ b/storage/heap/hp_rprev.c @@ -0,0 +1,98 @@ +/* Copyright (c) 2000-2002, 2005-2007 MySQL AB + Use is subject to license terms + + 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; version 2 of the License. + + 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA */ + +#include "heapdef.h" + + /* Read prev record for key */ + + +int heap_rprev(HP_INFO *info, uchar *record) +{ + uchar *pos; + HP_SHARE *share=info->s; + HP_KEYDEF *keyinfo; + DBUG_ENTER("heap_rprev"); + + if (info->lastinx < 0) + DBUG_RETURN(my_errno=HA_ERR_WRONG_INDEX); + keyinfo = share->keydef + info->lastinx; + if (keyinfo->algorithm == HA_KEY_ALG_BTREE) + { + heap_rb_param custom_arg; + + /* If no active record and last was not deleted */ + if (!(info->update & (HA_STATE_AKTIV | HA_STATE_NO_KEY | + HA_STATE_DELETED))) + { + if (info->update & HA_STATE_PREV_FOUND) + pos= 0; /* Can't search before first row */ + else + { + /* Last was 'next' after last record; search after last record */ + pos= tree_search_edge(&keyinfo->rb_tree, info->parents, + &info->last_pos, offsetof(TREE_ELEMENT, right)); + } + } + else if (info->last_pos) + pos = tree_search_next(&keyinfo->rb_tree, &info->last_pos, + offsetof(TREE_ELEMENT, right), + offsetof(TREE_ELEMENT, left)); + else + { + custom_arg.keyseg = keyinfo->seg; + custom_arg.key_length = keyinfo->length; + custom_arg.search_flag = SEARCH_SAME; + info->last_find_flag= HA_READ_KEY_OR_PREV; + pos = tree_search_key(&keyinfo->rb_tree, info->lastkey, info->parents, + &info->last_pos, info->last_find_flag, &custom_arg); + } + if (pos) + { + memcpy(&pos, pos + (*keyinfo->get_key_length)(keyinfo, pos), + sizeof(uchar*)); + info->current_ptr = pos; + } + else + { + my_errno = HA_ERR_KEY_NOT_FOUND; + } + } + else + { + if (info->current_ptr || (info->update & HA_STATE_NEXT_FOUND)) + { + if ((info->update & HA_STATE_DELETED)) + pos= hp_search(info, share->keydef + info->lastinx, info->lastkey, 3); + else + pos= hp_search(info, share->keydef + info->lastinx, info->lastkey, 2); + } + else + { + pos=0; /* Read next after last */ + my_errno=HA_ERR_KEY_NOT_FOUND; + } + } + if (!pos) + { + info->update=HA_STATE_PREV_FOUND; /* For heap_rprev */ + if (my_errno == HA_ERR_KEY_NOT_FOUND) + my_errno=HA_ERR_END_OF_FILE; + DBUG_RETURN(my_errno); + } + memcpy(record,pos,(size_t) share->reclength); + info->update=HA_STATE_AKTIV | HA_STATE_PREV_FOUND; + DBUG_RETURN(0); +} |