int mi_preload(MI_INFO *info, ulonglong key_map, my_bool ignore_leaves)
{
uint i;
ulong length, block_length= 0;
uchar *buff= NULL;
MYISAM_SHARE* share= info->s;
uint keys= share->state.header.keys;
MI_KEYDEF *keyinfo= share->keyinfo;
my_off_t key_file_length= share->state.state.key_file_length;
my_off_t pos= share->base.keystart;
DBUG_ENTER("mi_preload");
if (!keys || !mi_is_any_key_active(key_map) || key_file_length == pos)
DBUG_RETURN(0);
block_length= keyinfo[0].block_length;
if (ignore_leaves)
{
/* Check whether all indexes use the same block size */
for (i= 1 ; i < keys ; i++)
{
if (keyinfo[i].block_length != block_length)
DBUG_RETURN(my_errno= HA_ERR_NON_UNIQUE_BLOCK_SIZE);
}
}
else
block_length= share->key_cache->key_cache_block_size;
length= info->preload_buff_size/block_length * block_length;
set_if_bigger(length, block_length);
if (!(buff= (uchar *) my_malloc(length, MYF(MY_WME))))
DBUG_RETURN(my_errno= HA_ERR_OUT_OF_MEM);
if (flush_key_blocks(share->key_cache,share->kfile, FLUSH_RELEASE))
goto err;
do
{
/* Read the next block of index file into the preload buffer */
if ((my_off_t) length > (key_file_length-pos))
length= (ulong) (key_file_length-pos);
if (mysql_file_pread(share->kfile, (uchar*) buff, length, pos,
MYF(MY_FAE|MY_FNABP)))
goto err;
if (ignore_leaves)
{
uchar *end= buff+length;
do
{
if (mi_test_if_nod(buff))
{
if (key_cache_insert(share->key_cache,
share->kfile, pos, DFLT_INIT_HITS,
(uchar*) buff, block_length))
goto err;
}
pos+= block_length;
}
while ((buff+= block_length) != end);
buff= end-length;
}
else
{
if (key_cache_insert(share->key_cache,
share->kfile, pos, DFLT_INIT_HITS,
(uchar*) buff, length))
goto err;
pos+= length;
}
}
while (pos != key_file_length);
my_free(buff);
DBUG_RETURN(0);
err:
my_free(buff);
DBUG_RETURN(my_errno= errno);
}
my_bool _ma_read_cache(MARIA_HA *handler, IO_CACHE *info, uchar *buff,
my_off_t pos, size_t length, uint flag)
{
size_t read_length,in_buff_length;
my_off_t offset;
uchar *in_buff_pos;
DBUG_ENTER("_ma_read_cache");
if (pos < info->pos_in_file)
{
read_length=length;
if ((my_off_t) read_length > (my_off_t) (info->pos_in_file-pos))
read_length=(uint) (info->pos_in_file-pos);
info->seek_not_done=1;
if (mysql_file_pread(info->file,buff,read_length,pos,MYF(MY_NABP)))
DBUG_RETURN(1);
if (!(length-=read_length))
DBUG_RETURN(0);
pos+=read_length;
buff+=read_length;
}
if (pos >= info->pos_in_file &&
(offset= (my_off_t) (pos - info->pos_in_file)) <
(my_off_t) (info->read_end - info->request_pos))
{
in_buff_pos=info->request_pos+(uint) offset;
in_buff_length= MY_MIN(length,(size_t) (info->read_end-in_buff_pos));
memcpy(buff,info->request_pos+(uint) offset,(size_t) in_buff_length);
if (!(length-=in_buff_length))
DBUG_RETURN(0);
pos+=in_buff_length;
buff+=in_buff_length;
}
else
in_buff_length=0;
if (flag & READING_NEXT)
{
if (pos != (info->pos_in_file +
(uint) (info->read_end - info->request_pos)))
{
info->pos_in_file=pos; /* Force start here */
info->read_pos=info->read_end=info->request_pos; /* Everything used */
info->seek_not_done=1;
}
else
info->read_pos=info->read_end; /* All block used */
if (!(*info->read_function)(info,buff,length))
DBUG_RETURN(0);
read_length=info->error;
}
else
{
info->seek_not_done=1;
if ((read_length=mysql_file_pread(info->file,buff,length,pos,MYF(0))) == length)
DBUG_RETURN(0);
}
if (!(flag & READING_HEADER) || (int) read_length == -1 ||
read_length+in_buff_length < 3)
{
DBUG_PRINT("error",
("Error %d reading next-multi-part block (Got %d bytes)",
my_errno, (int) read_length));
if (!my_errno || my_errno == HA_ERR_FILE_TOO_SHORT)
{
if (!handler->in_check_table)
_ma_set_fatal_error(handler->s, HA_ERR_WRONG_IN_RECORD);
else
my_errno= HA_ERR_WRONG_IN_RECORD;
}
DBUG_RETURN(1);
}
bzero(buff+read_length,MARIA_BLOCK_INFO_HEADER_LENGTH - in_buff_length -
read_length);
DBUG_RETURN(0);
} /* _ma_read_cache */