mariadb/storage/maria/ma_checksum.c
unknown f094eff1d9 Injecting more "const" declarations into code which does not change
pointed data.
I ran gcc -Wcast-qual on storage/maria, this identified un-needed casts,
a couple of functions which said they had a const parameter though
they changed the pointed content! This is fixed here. Some suspicious
places receive a comment.
The original intention of running -Wcast-qual was to find what code
changes R-tree keys: I added const words, but hidden casts
like those of int2store (casts target to (uint16*)) removed const
checking; -Wcast-qual helped find those hidden casts.
Log handler does not change the content pointed by LEX_STRING::str it
receives, so we now use a struct which has a const inside, to emphasize
this and be able to pass "const uchar*" buffers to log handler
without fear of their content being changed by it.
One-line fix for a merge glitch (when merging from MyISAM).


include/m_string.h:
  As Maria's log handler uses LEX_STRING but never changes the content
  pointed by LEX_STRING::str, and assigns uchar* into this member most
  of the time, we introduce a new struct LEX_CUSTRING
  (C const U unsigned) for the log handler.
include/my_global.h:
  In macros which read pointed content: use const pointers so that
  gcc -Wcast-qual does not warn about casting a const pointer to non-const.
include/my_handler.h:
  In macros which read pointed content: use const pointers so that
  gcc -Wcast-qual does not warn about casting a const pointer to non-const.
  ha_find_null() does not change *a.
include/my_sys.h:
  insert_dynamic() does not change *element.
include/myisampack.h:
  In macros which read pointed content: use const pointers so that
  gcc -Wcast-qual does not warn about casting a const pointer to non-const.
mysys/array.c:
  insert_dynamic() does not change *element
mysys/my_handler.c:
  ha_find_null() does not change *a
storage/maria/ma_bitmap.c:
  Log handler receives const strings now
storage/maria/ma_blockrec.c:
  Log handler receives const strings now.
  _ma_apply_undo_row_delete/update() do change *header.
storage/maria/ma_blockrec.h:
  correct prototype
storage/maria/ma_check.c:
  Log handler receives const strings now. Un-needed casts
storage/maria/ma_checkpoint.c:
  Log handler receives const strings now
storage/maria/ma_checksum.c:
  unneeded cast
storage/maria/ma_commit.c:
  Log handler receives const strings now
storage/maria/ma_create.c:
  Log handler receives const strings now
storage/maria/ma_dbug.c:
  fixing warning of gcc -Wcast-qual
storage/maria/ma_delete.c:
  Log handler receives const strings now
storage/maria/ma_delete_all.c:
  Log handler receives const strings now
storage/maria/ma_delete_table.c:
  Log handler receives const strings now
storage/maria/ma_dynrec.c:
  fixing some warnings of gcc -Wcast-qual. Unneeded casts removed.
  Comment about function which lies.
storage/maria/ma_ft_parser.c:
  fix for warnings of gcc -Wcast-qual, removing unneeded casts
storage/maria/ma_ft_update.c:
  less casts, comment
storage/maria/ma_key.c:
  less casts, stay const (warnings of gcc -Wcast-qual)
storage/maria/ma_key_recover.c:
  Log handler receives const strings now
storage/maria/ma_loghandler.c:
  Log handler receives const strings now
storage/maria/ma_loghandler.h:
  Log handler receives const strings now
storage/maria/ma_loghandler_lsn.h:
  In macros which read pointed content: use const pointers so that
  gcc -Wcast-qual does not warn about casting a const pointer to non-const.
storage/maria/ma_page.c:
  Log handler receives const strings now; more const
storage/maria/ma_recovery.c:
  Log handler receives const strings now
storage/maria/ma_rename.c:
  Log handler receives const strings now
storage/maria/ma_rt_index.c:
  more const, to emphasize that functions don't change pointed content.
  best_key= NULL was forgotten during merge from MyISAM a few days ago,
  was causing a Valgrind warning
storage/maria/ma_rt_index.h:
  new proto
storage/maria/ma_rt_key.c:
  more const
storage/maria/ma_rt_key.h:
  new proto
storage/maria/ma_rt_mbr.c:
  more const for functions which deserve it
storage/maria/ma_rt_mbr.h:
  new prototype
storage/maria/ma_rt_split.c:
  make const what is not changed.
storage/maria/ma_search.c:
  un-needed casts, more const
storage/maria/ma_sp_key.c:
  more const
storage/maria/ma_unique.c:
  un-needed casts.
storage/maria/ma_write.c:
  Log handler receives const strings now
storage/maria/maria_def.h:
  some more const
storage/maria/unittest/ma_test_loghandler-t.c:
  Log handler receives const strings now
storage/maria/unittest/ma_test_loghandler_first_lsn-t.c:
  Log handler receives const strings now
storage/maria/unittest/ma_test_loghandler_max_lsn-t.c:
  Log handler receives const strings now
storage/maria/unittest/ma_test_loghandler_multigroup-t.c:
  Log handler receives const strings now
storage/maria/unittest/ma_test_loghandler_multithread-t.c:
  Log handler receives const strings now
storage/maria/unittest/ma_test_loghandler_noflush-t.c:
  Log handler receives const strings now
storage/maria/unittest/ma_test_loghandler_nologs-t.c:
  Log handler receives const strings now
storage/maria/unittest/ma_test_loghandler_pagecache-t.c:
  Log handler receives const strings now
storage/maria/unittest/ma_test_loghandler_purge-t.c:
  Log handler receives const strings now
2008-04-03 15:40:25 +02:00

89 lines
2.5 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
/* Calculate a checksum for a row */
#include "maria_def.h"
/**
Calculate a checksum for the record
_ma_checksum()
@param info Maria handler
@param record Record
@note
To ensure that the checksum is independent of the row format
we need to always calculate the checksum in the original field order.
@return checksum
*/
ha_checksum _ma_checksum(MARIA_HA *info, const uchar *record)
{
ha_checksum crc=0;
uint i,end;
MARIA_COLUMNDEF *base_column= info->s->columndef;
uint16 *column_nr= info->s->column_nr;
if (info->s->base.null_bytes)
crc= my_checksum(crc, record, info->s->base.null_bytes);
for (i= 0, end= info->s->base.fields ; i < end ; i++)
{
MARIA_COLUMNDEF *column= base_column + column_nr[i];
const uchar *pos;
ulong length;
if (record[column->null_pos] & column->null_bit)
continue; /* Null field */
pos= record + column->offset;
switch (column->type) {
case FIELD_BLOB:
{
uint blob_size_length= column->length- portable_sizeof_char_ptr;
length= _ma_calc_blob_length(blob_size_length, pos);
if (length)
{
memcpy((char*) &pos, pos + blob_size_length, sizeof(char*));
crc= my_checksum(crc, pos, length);
}
continue;
}
case FIELD_VARCHAR:
{
uint pack_length= column->fill_length;
if (pack_length == 1)
length= (ulong) *pos;
else
length= uint2korr(pos);
pos+= pack_length; /* Skip length information */
break;
}
default:
length= column->length;
break;
}
crc= my_checksum(crc, pos, length);
}
return crc;
}
ha_checksum _ma_static_checksum(MARIA_HA *info, const uchar *pos)
{
return my_checksum(0, pos, info->s->base.reclength);
}