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 (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;
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);
}
if (hp_extract_record(info, record, pos))
{
DBUG_RETURN(my_errno);
}
info->update=HA_STATE_AKTIV | HA_STATE_PREV_FOUND;
DBUG_RETURN(0);
}
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);
}
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);
}
int aby_rprev(HPA_INFO *info, uchar *record)
{
uchar *pos;
HPA_SHARE *share=info->s;
HPA_KEYDEF *keyinfo;
DBUG_ENTER("aby_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)
{
aby_rb_param custom_arg;
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;
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*));
if (ABY_LOCK == ABY_HEAP)
info->current_ptr = pos;
else if (ABY_LOCK == ABY_ROW)
info->current_ptr_array[((pid_t)syscall(SYS_gettid))%ROWTHRDS] = pos;
}
else
{
my_errno = HA_ERR_KEY_NOT_FOUND;
}
}
else
{
if (ABY_LOCK == ABY_HEAP)
{
if (info->current_ptr || (info->update & HA_STATE_NEXT_FOUND))
{
if ((info->update & HA_STATE_DELETED))
pos= hpa_search(info, share->keydef + info->lastinx, info->lastkey, 3);
else
pos= hpa_search(info, share->keydef + info->lastinx, info->lastkey, 2);
}
else
{
pos=0; /* Read next after last */
my_errno=HA_ERR_KEY_NOT_FOUND;
}
}
else if (ABY_LOCK == ABY_ROW)
{
if (info->current_ptr_array[((pid_t)syscall(SYS_gettid))%ROWTHRDS]
|| (info->update & HA_STATE_NEXT_FOUND))
{
if ((info->update & HA_STATE_DELETED))
pos= hpa_search(info, share->keydef + info->lastinx, info->lastkey, 3);
else
pos= hpa_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 aby_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);
}