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

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

1 files changed, 106 insertions, 0 deletions

diff --git a/storage/maria/ma_rprev.c b/storage/maria/ma_rprev.c
new file mode 100644
index 00000000..15010d96
--- /dev/null
+++ b/storage/maria/ma_rprev.c
@@ -0,0 +1,106 @@
+/* Copyright (C) 2006 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; 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 "maria_def.h"
+
+	/*
+	   Read previous row with the same key as previous read
+	   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 maria_rprev(MARIA_HA *info, uchar *buf, int inx)
+{
+  int error,changed;
+  register uint flag;
+  MARIA_SHARE *share= info->s;
+  MARIA_KEYDEF *keyinfo;
+  check_result_t check= CHECK_POS;
+  DBUG_ENTER("maria_rprev");
+
+  if ((inx = _ma_check_index(info,inx)) < 0)
+    DBUG_RETURN(my_errno);
+  flag=SEARCH_SMALLER;				/* Read previous */
+  if (info->cur_row.lastpos == HA_OFFSET_ERROR &&
+      info->update & HA_STATE_NEXT_FOUND)
+    flag=0;					/* Read last */
+
+  if (fast_ma_readinfo(info))
+    DBUG_RETURN(my_errno);
+  keyinfo= share->keyinfo + inx;
+  changed= _ma_test_if_changed(info);
+  if (share->lock_key_trees)
+    mysql_rwlock_rdlock(&keyinfo->root_lock);
+  if (!flag)
+    error= _ma_search_last(info, keyinfo, share->state.key_root[inx]);
+  else if (!changed)
+    error= _ma_search_next(info, &info->last_key,
+                           flag | info->last_key.flag,
+                           share->state.key_root[inx]);
+  else
+    error= _ma_search(info, &info->last_key, flag | info->last_key.flag,
+                      share->state.key_root[inx]);
+
+  if (!error)
+  {
+    my_off_t cur_keypage= info->last_keypage;
+    while (!(*share->row_is_visible)(info) ||
+           ((check= ma_check_index_cond(info, inx, buf)) == CHECK_NEG))
+    {
+      /*
+        If we are at the last (i.e. first?) key on the key page, 
+        allow writers to access the index.
+      */
+      if (info->last_keypage != cur_keypage)
+      {
+        cur_keypage= info->last_keypage;
+        if (ma_yield_and_check_if_killed(info, inx))
+        {
+          error= 1;
+          break;
+        }
+      }
+
+      /* Skip rows that are inserted by other threads since we got a lock */
+      if  ((error= _ma_search_next(info, &info->last_key,
+                                   SEARCH_SMALLER,
+                                   share->state.key_root[inx])))
+        break;
+    }
+  }
+  if (share->lock_key_trees)
+    mysql_rwlock_unlock(&keyinfo->root_lock);
+  info->update&= (HA_STATE_CHANGED | HA_STATE_ROW_CHANGED);
+  info->update|= HA_STATE_PREV_FOUND;
+
+  if (error || check != CHECK_POS)
+  {
+    fast_ma_writeinfo(info);
+    if (my_errno == HA_ERR_KEY_NOT_FOUND)
+      my_errno= HA_ERR_END_OF_FILE;
+  }
+  else if (!buf)
+  {
+    fast_ma_writeinfo(info);
+    DBUG_RETURN(info->cur_row.lastpos == HA_OFFSET_ERROR ? my_errno : 0);
+  }
+  else if (!(*info->read_record)(info, buf, info->cur_row.lastpos))
+  {
+    info->update|= HA_STATE_AKTIV;		/* Record is read */
+    DBUG_RETURN(0);
+  }
+  DBUG_RETURN(my_errno);
+} /* maria_rprev */