Drizzled Public API Documentation

mi_delete_all.cc
1 /* Copyright (C) 2000-2003, 2005 MySQL AB
2 
3  This program is free software; you can redistribute it and/or modify
4  it under the terms of the GNU General Public License as published by
5  the Free Software Foundation; version 2 of the License.
6 
7  This program is distributed in the hope that it will be useful,
8  but WITHOUT ANY WARRANTY; without even the implied warranty of
9  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10  GNU General Public License for more details.
11 
12  You should have received a copy of the GNU General Public License
13  along with this program; if not, write to the Free Software
14  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
15 
16 /* Remove all rows from a MyISAM table */
17 /* This clears the status information and truncates files */
18 
19 #include "myisam_priv.h"
20 
21 int mi_delete_all_rows(MI_INFO *info)
22 {
23  uint32_t i;
24  MYISAM_SHARE *share=info->s;
25  MI_STATE_INFO *state=&share->state;
26 
27  if (share->options & HA_OPTION_READ_ONLY_DATA)
28  {
29  return(errno=EACCES);
30  }
31  if (_mi_readinfo(info,F_WRLCK,1))
32  return(errno);
33  if (_mi_mark_file_changed(info))
34  goto err;
35 
36  info->state->records=info->state->del=state->split=0;
37  state->dellink = HA_OFFSET_ERROR;
38  state->sortkey= UINT16_MAX;
39  info->state->key_file_length=share->base.keystart;
40  info->state->data_file_length=0;
41  info->state->empty=info->state->key_empty=0;
42  info->state->checksum=0;
43 
44  for (i=share->base.max_key_block_length/MI_MIN_KEY_BLOCK_LENGTH ; i-- ; )
45  state->key_del[i]= HA_OFFSET_ERROR;
46  for (i=0 ; i < share->base.keys ; i++)
47  state->key_root[i]= HA_OFFSET_ERROR;
48 
49  /*
50  If we are using delayed keys or if the user has done changes to the tables
51  since it was locked then there may be key blocks in the key cache
52  */
53  if (ftruncate(info->dfile, 0) || ftruncate(share->kfile, share->base.keystart))
54  goto err;
55  _mi_writeinfo(info,WRITEINFO_UPDATE_KEYFILE);
56  return(0);
57 
58 err:
59  {
60  int save_errno=errno;
61  _mi_writeinfo(info,WRITEINFO_UPDATE_KEYFILE);
62  info->update|=HA_STATE_WRITTEN; /* Buffer changed */
63  return(errno=save_errno);
64  }
65 } /* mi_delete */