mariadb/storage/maria/ma_cache.c
Monty 3d241eb948 Improve error reporting in Aria
This patch fixes the following issues in Aria error reporting in case
of read errors & crashed tables:
- Added the table name to the most error messages, including in case of
  read errors or when encrypting/decrypting a table. The format for
  error messages was changed sligtly to accomodate logging of errors
  from lower level routines.
- If we got an read error from storage (hard disk, ssd, S3 etc) we only
  reported 'table is crashed'. Now the error number from the storage
  is reported.
- Added checking of read failure from records_in_range()
- Calls to ma_set_fatal_error() did not inform the SQL level of
  errors (to not spam the user with multiple error messages).
  Now the first error message and any fatal error messages are reported
  to the user.
2022-06-07 20:43:11 +03:00

119 lines
4 KiB
C

/* Copyright (C) 2006 MySQL AB & MySQL Finland AB & TCX DataKonsult 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 Street, Fifth Floor, Boston, MA 02110-1335 USA */
/*
Functions for read record cacheing with maria
Used for reading dynamic/compressed records from datafile.
Can fetch data directly from file (outside cache),
if reading a small chunk straight before the cached part (with possible
overlap).
Can be explicitly asked not to use cache (by not setting READING_NEXT in
flag) - useful for occasional out-of-cache reads, when the next read is
expected to hit the cache again.
Allows "partial read" errors in the record header (when READING_HEADER flag
is set) - unread part is bzero'ed
Note: out-of-cache reads are enabled for shared IO_CACHE's too,
as these reads will be cached by OS cache (and my_pread is always atomic)
*/
#include "maria_def.h"
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");
DBUG_ASSERT(!(info->myflags & MY_ENCRYPT));
if (unlikely(pos >= info->end_of_file) && (flag & READING_HEADER))
DBUG_RETURN(-1);
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 (!_my_b_read(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)
{
if ((flag & READING_HEADER) && read_length + in_buff_length == 0)
DBUG_RETURN(-1); /* End of file */
DBUG_PRINT("error",
("Error %d reading next-multi-part block (Got %d of %d bytes)",
my_errno, (int) read_length, (int) length));
if (!my_errno || my_errno == HA_ERR_FILE_TOO_SHORT)
{
if (!handler->in_check_table)
_ma_set_fatal_error(handler, HA_ERR_FILE_TOO_SHORT);
if (!my_errno)
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 */