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/* Copyright (C) 2000-2004, 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 St, Fifth Floor, Boston, MA 02110-1301 USA */
/* Read and write key blocks */
#include "myisam_priv.h"
using namespace drizzled;
/* Fetch a key-page in memory */
unsigned char *_mi_fetch_keypage(MI_INFO *info, MI_KEYDEF *keyinfo,
internal::my_off_t page, int, unsigned char *buff, int)
{
if (not pread(info->s->kfile, buff, keyinfo->block_length, page))
{
info->last_keypage=HA_OFFSET_ERROR;
mi_print_error(info->s, HA_ERR_CRASHED);
errno=HA_ERR_CRASHED;
return(0);
}
unsigned char* tmp= buff;
if (tmp == info->buff)
info->buff_used=1;
info->last_keypage=page;
uint32_t page_size=mi_getint(tmp);
if (page_size < 4 || page_size > keyinfo->block_length)
{
info->last_keypage = HA_OFFSET_ERROR;
mi_print_error(info->s, HA_ERR_CRASHED);
errno = HA_ERR_CRASHED;
tmp = 0;
}
return(tmp);
} /* _mi_fetch_keypage */
/* Write a key-page on disk */
int _mi_write_keypage(MI_INFO *info, MI_KEYDEF *keyinfo,
internal::my_off_t page, int, unsigned char *buff)
{
uint32_t length;
#ifndef FAST /* Safety check */
if (page < info->s->base.keystart ||
page+keyinfo->block_length > info->state->key_file_length ||
(page & (MI_MIN_KEY_BLOCK_LENGTH-1)))
{
errno=EINVAL;
return((-1));
}
#endif
if ((length=keyinfo->block_length) > IO_SIZE*2 &&
info->state->key_file_length != page+length)
length= ((mi_getint(buff)+IO_SIZE-1) & (uint) ~(IO_SIZE-1));
#ifdef HAVE_VALGRIND
{
length=mi_getint(buff);
memset(buff+length, 0, keyinfo->block_length-length);
length=keyinfo->block_length;
}
#endif
return not pwrite(info->s->kfile, buff, length, page);
} /* mi_write_keypage */
/* Remove page from disk */
int _mi_dispose(MI_INFO *info, MI_KEYDEF *keyinfo, internal::my_off_t pos, int)
{
internal::my_off_t old_link;
unsigned char buff[8];
old_link= info->s->state.key_del[keyinfo->block_size_index];
info->s->state.key_del[keyinfo->block_size_index]= pos;
mi_sizestore(buff,old_link);
info->s->state.changed|= STATE_NOT_SORTED_PAGES;
return not pwrite(info->s->kfile, buff, sizeof(buff), pos);
} /* _mi_dispose */
/* Make new page on disk */
internal::my_off_t _mi_new(MI_INFO *info, MI_KEYDEF *keyinfo, int)
{
internal::my_off_t pos;
unsigned char buff[8];
if ((pos= info->s->state.key_del[keyinfo->block_size_index]) ==
HA_OFFSET_ERROR)
{
if (info->state->key_file_length >=
info->s->base.max_key_file_length - keyinfo->block_length)
{
errno=HA_ERR_INDEX_FILE_FULL;
return(HA_OFFSET_ERROR);
}
pos=info->state->key_file_length;
info->state->key_file_length+= keyinfo->block_length;
}
else if (pread(info->s->kfile, buff, sizeof(buff), pos))
info->s->state.key_del[keyinfo->block_size_index]= mi_sizekorr(buff);
else
pos= HA_OFFSET_ERROR;
info->s->state.changed|= STATE_NOT_SORTED_PAGES;
return(pos);
} /* _mi_new */
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