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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-04 18:00:34 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-04 18:00:34 +0000
commit3f619478f796eddbba6e39502fe941b285dd97b1 (patch)
treee2c7b5777f728320e5b5542b6213fd3591ba51e2 /storage/heap/hp_rprev.c
parentInitial commit. (diff)
downloadmariadb-3f619478f796eddbba6e39502fe941b285dd97b1.tar.xz
mariadb-3f619478f796eddbba6e39502fe941b285dd97b1.zip
Adding upstream version 1:10.11.6.upstream/1%10.11.6upstream
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.c98
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);
+}