Adding upstream version 1:10.11.6.upstream/1%10.11.6

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 130 insertions, 0 deletions

diff --git a/storage/heap/hp_rnext.c b/storage/heap/hp_rnext.c
new file mode 100644
index 00000000..f227ce4d
--- /dev/null
+++ b/storage/heap/hp_rnext.c
@@ -0,0 +1,130 @@
+/* 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 next record with the same key */
+
+int heap_rnext(HP_INFO *info, uchar *record)
+{
+  uchar *pos;
+  HP_SHARE *share=info->s;
+  HP_KEYDEF *keyinfo;
+  DBUG_ENTER("heap_rnext");
+  
+  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_NEXT_FOUND)
+        pos= 0;                            /* Can't search after last row */
+      else
+      {
+        /* Last was 'prev' before first record; search after first record */
+        pos= tree_search_edge(&keyinfo->rb_tree, info->parents,
+                              &info->last_pos, offsetof(TREE_ELEMENT, left));
+      }
+    }
+    else if (info->last_pos)
+    {
+      /*
+        We enter this branch for non-DELETE queries after heap_rkey()
+        or heap_rfirst(). As last key position (info->last_pos) is available,
+        we only need to climb the tree using tree_search_next().
+      */
+      pos = tree_search_next(&keyinfo->rb_tree, &info->last_pos,
+                             offsetof(TREE_ELEMENT, left),
+                             offsetof(TREE_ELEMENT, right));
+    }
+    else if (!info->lastkey_len)
+    {
+      /*
+        We enter this branch only for DELETE queries after heap_rfirst(). E.g.
+        DELETE FROM t1 WHERE a<10. As last key position is not available
+        (last key is removed by heap_delete()), we must restart search as it
+        is done in heap_rfirst().
+
+        It should be safe to handle this situation without this branch. That is
+        branch below should find smallest element in a tree as lastkey_len is
+        zero. tree_search_edge() is a kind of optimisation here as it should be
+        faster than tree_search_key().
+      */
+      pos= tree_search_edge(&keyinfo->rb_tree, info->parents,
+                            &info->last_pos, offsetof(TREE_ELEMENT, left));
+    }
+    else
+    {
+      /*
+        We enter this branch only for DELETE queries after heap_rkey(). E.g.
+        DELETE FROM t1 WHERE a=10. As last key position is not available
+        (last key is removed by heap_delete()), we must restart search as it
+        is done in heap_rkey().
+      */
+      custom_arg.keyseg = keyinfo->seg;
+      custom_arg.key_length = info->lastkey_len;
+      custom_arg.search_flag = SEARCH_SAME | SEARCH_FIND;
+      info->last_find_flag= HA_READ_KEY_OR_NEXT;
+      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_hash_ptr)
+      pos= hp_search_next(info, keyinfo, info->lastkey,
+			   info->current_hash_ptr);
+    else
+    {
+      if (!info->current_ptr && (info->update & HA_STATE_NEXT_FOUND))
+      {
+	pos=0;					/* Read next after last */
+	my_errno=HA_ERR_KEY_NOT_FOUND;
+      }
+      else if (!info->current_ptr)		/* Deleted or first call */
+	pos= hp_search(info, keyinfo, info->lastkey, 0);
+      else
+	pos= hp_search(info, keyinfo, info->lastkey, 1);
+    }
+  }
+  if (!pos)
+  {
+    info->update=HA_STATE_NEXT_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_NEXT_FOUND;
+  DBUG_RETURN(0);
+}