mariadb/storage/heap/hp_rrnd.c
2013-03-19 15:53:48 +01:00

105 lines
3 KiB
C

/* Copyright (C) 2000-2002, 2004, 2006 MySQL 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 02110-1301, USA */
/* Read a record from a random position */
#include "heapdef.h"
/*
Returns one of following values:
0 = Ok.
HA_ERR_RECORD_DELETED = Record is deleted.
HA_ERR_END_OF_FILE = EOF.
*/
int heap_rrnd(register HP_INFO *info, uchar *record, uchar *pos)
{
HP_SHARE *share=info->s;
DBUG_ENTER("heap_rrnd");
DBUG_PRINT("enter",("info: 0x%lx pos: %lx",(long) info, (long) pos));
info->lastinx= -1;
if (!(info->current_ptr= pos))
{
info->update= 0;
DBUG_RETURN(my_errno= HA_ERR_END_OF_FILE);
}
if (!info->current_ptr[share->reclength])
{
info->update= HA_STATE_PREV_FOUND | HA_STATE_NEXT_FOUND;
DBUG_RETURN(my_errno=HA_ERR_RECORD_DELETED);
}
info->update=HA_STATE_PREV_FOUND | HA_STATE_NEXT_FOUND | HA_STATE_AKTIV;
memcpy(record,info->current_ptr,(size_t) share->reclength);
DBUG_PRINT("exit", ("found record at 0x%lx", (long) info->current_ptr));
info->current_hash_ptr=0; /* Can't use rnext */
DBUG_RETURN(0);
} /* heap_rrnd */
#ifdef WANT_OLD_HEAP_VERSION
/*
If pos == -1 then read next record
Returns one of following values:
0 = Ok.
HA_ERR_RECORD_DELETED = Record is deleted.
HA_ERR_END_OF_FILE = EOF.
*/
int heap_rrnd_old(register HP_INFO *info, uchar *record, ulong pos)
{
HP_SHARE *share=info->s;
DBUG_ENTER("heap_rrnd");
DBUG_PRINT("enter",("info: 0x%lx pos: %ld",info,pos));
info->lastinx= -1;
if (pos == (ulong) -1)
{
pos= ++info->current_record;
if (pos % share->block.records_in_block && /* Quick next record */
pos < share->records+share->deleted &&
(info->update & HA_STATE_PREV_FOUND))
{
info->current_ptr+=share->block.recbuffer;
goto end;
}
}
else
info->current_record=pos;
if (pos >= share->records+share->deleted)
{
info->update= 0;
DBUG_RETURN(my_errno= HA_ERR_END_OF_FILE);
}
/* Find record number pos */
hp_find_record(info, pos);
end:
if (!info->current_ptr[share->reclength])
{
info->update= HA_STATE_PREV_FOUND | HA_STATE_NEXT_FOUND;
DBUG_RETURN(my_errno=HA_ERR_RECORD_DELETED);
}
info->update=HA_STATE_PREV_FOUND | HA_STATE_NEXT_FOUND | HA_STATE_AKTIV;
memcpy(record,info->current_ptr,(size_t) share->reclength);
DBUG_PRINT("exit",("found record at 0x%lx",info->current_ptr));
info->current_hash_ptr=0; /* Can't use rnext */
DBUG_RETURN(0);
} /* heap_rrnd */
#endif /* WANT_OLD_HEAP_VERSION */