diff options
Diffstat (limited to 'storage/myisam/mi_rrnd.c')
-rw-r--r-- | storage/myisam/mi_rrnd.c | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/storage/myisam/mi_rrnd.c b/storage/myisam/mi_rrnd.c new file mode 100644 index 00000000..4e49e792 --- /dev/null +++ b/storage/myisam/mi_rrnd.c @@ -0,0 +1,60 @@ +/* Copyright (c) 2000-2002, 2004-2007 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 */ + +/* Read a record with random-access. The position to the record must + get by MI_INFO. The next record can be read with pos= MI_POS_ERROR */ + + +#include "myisamdef.h" + +/* + Read a row based on position. + If filepos= HA_OFFSET_ERROR then read next row + Return values + Returns one of following values: + 0 = Ok. + HA_ERR_RECORD_DELETED = Record is deleted. + HA_ERR_END_OF_FILE = EOF. +*/ + +int mi_rrnd(MI_INFO *info, uchar *buf, register my_off_t filepos) +{ + my_bool skip_deleted_blocks; + DBUG_ENTER("mi_rrnd"); + + skip_deleted_blocks=0; + + if (filepos == HA_OFFSET_ERROR) + { + skip_deleted_blocks=1; + if (info->lastpos == HA_OFFSET_ERROR) /* First read ? */ + filepos= info->s->pack.header_length; /* Read first record */ + else + filepos= info->nextpos; + } + + if (info->once_flags & RRND_PRESERVE_LASTINX) + info->once_flags&= ~RRND_PRESERVE_LASTINX; + else + info->lastinx= -1; /* Can't forward or backward */ + /* Init all but update-flag */ + info->update&= (HA_STATE_CHANGED | HA_STATE_ROW_CHANGED); + + if (info->opt_flag & WRITE_CACHE_USED && flush_io_cache(&info->rec_cache)) + DBUG_RETURN(my_errno); + + DBUG_RETURN ((*info->s->read_rnd)(info,buf,filepos,skip_deleted_blocks)); +} |