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/* Copyright (C) 2000-2003, 2005 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
/* Remove all rows from a MyISAM table */
/* This clears the status information and truncates files */
#include "myisamdef.h"
int mi_delete_all_rows(MI_INFO *info)
{
uint i;
MYISAM_SHARE *share=info->s;
MI_STATE_INFO *state=&share->state;
DBUG_ENTER("mi_delete_all_rows");
if (share->options & HA_OPTION_READ_ONLY_DATA)
{
DBUG_RETURN(my_errno=EACCES);
}
if (_mi_readinfo(info,F_WRLCK,1))
DBUG_RETURN(my_errno);
if (_mi_mark_file_changed(info))
goto err;
info->state->records=info->state->del=state->split=0;
state->dellink = HA_OFFSET_ERROR;
state->sortkey= (ushort) ~0;
info->state->key_file_length=share->base.keystart;
info->state->data_file_length=0;
info->state->empty=info->state->key_empty=0;
info->state->checksum=0;
for (i=share->base.max_key_block_length/MI_MIN_KEY_BLOCK_LENGTH ; i-- ; )
state->key_del[i]= HA_OFFSET_ERROR;
for (i=0 ; i < share->base.keys ; i++)
state->key_root[i]= HA_OFFSET_ERROR;
myisam_log_command(MI_LOG_DELETE_ALL,info,(uchar*) 0,0,0);
/*
If we are using delayed keys or if the user has done changes to the tables
since it was locked then there may be key blocks in the key cache
*/
flush_key_blocks(share->key_cache, share->kfile, &share->dirty_part_map,
FLUSH_IGNORE_CHANGED);
#ifdef HAVE_MMAP
if (share->file_map)
mi_munmap_file(info);
#endif
if (my_chsize(info->dfile, 0, 0, MYF(MY_WME)) ||
my_chsize(share->kfile, share->base.keystart, 0, MYF(MY_WME)) )
goto err;
VOID(_mi_writeinfo(info,WRITEINFO_UPDATE_KEYFILE));
#ifdef HAVE_MMAP
/* Map again */
if (share->file_map)
mi_dynmap_file(info, (my_off_t) 0);
#endif
allow_break(); /* Allow SIGHUP & SIGINT */
DBUG_RETURN(0);
err:
{
int save_errno=my_errno;
VOID(_mi_writeinfo(info,WRITEINFO_UPDATE_KEYFILE));
info->update|=HA_STATE_WRITTEN; /* Buffer changed */
allow_break(); /* Allow SIGHUP & SIGINT */
DBUG_RETURN(my_errno=save_errno);
}
} /* mi_delete */
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