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/*****************************************************************************
Copyright (c) 1995, 2016, Oracle and/or its affiliates. All Rights Reserved.
Copyright (c) 2017, 2022, MariaDB Corporation.
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
*****************************************************************************/
/**************************************************//**
@file buf/buf0checksum.cc
Buffer pool checksum functions, also linked from /extra/innochecksum.cc
Created Aug 11, 2011 Vasil Dimov
*******************************************************/
#include "buf0checksum.h"
#include "fil0fil.h"
#include "ut0rnd.h"
#ifndef UNIV_INNOCHECKSUM
#include "srv0srv.h"
#endif /* !UNIV_INNOCHECKSUM */
/** Calculate the CRC32 checksum of a page. The value is stored to the page
when it is written to a file and also checked for a match when reading from
the file. Note that we must be careful to calculate the same value on all
architectures.
@param[in] page buffer page (srv_page_size bytes)
@return CRC-32C */
uint32_t buf_calc_page_crc32(const byte* page)
{
/* Note: innodb_checksum_algorithm=crc32 could and should have
included the entire page in the checksum, and CRC-32 values
should be combined with the CRC-32 function, not with
exclusive OR. We stick to the current algorithm in order to
remain compatible with old data files. */
return my_crc32c(0, page + FIL_PAGE_OFFSET,
FIL_PAGE_FILE_FLUSH_LSN_OR_KEY_VERSION
- FIL_PAGE_OFFSET)
^ my_crc32c(0, page + FIL_PAGE_DATA,
srv_page_size
- (FIL_PAGE_DATA + FIL_PAGE_END_LSN_OLD_CHKSUM));
}
#ifndef UNIV_INNOCHECKSUM
/** Calculate a checksum which is stored to the page when it is written
to a file. Note that we must be careful to calculate the same value on
32-bit and 64-bit architectures.
@param[in] page file page (srv_page_size bytes)
@return checksum */
uint32_t
buf_calc_page_new_checksum(const byte* page)
{
ulint checksum;
/* Since the field FIL_PAGE_FILE_FLUSH_LSN, and in versions <= 4.1.x
FIL_PAGE_ARCH_LOG_NO_OR_SPACE_ID, are written outside the buffer pool
to the first pages of data files, we have to skip them in the page
checksum calculation.
We must also skip the field FIL_PAGE_SPACE_OR_CHKSUM where the
checksum is stored, and also the last 8 bytes of page because
there we store the old formula checksum. */
checksum = ut_fold_binary(page + FIL_PAGE_OFFSET,
FIL_PAGE_FILE_FLUSH_LSN_OR_KEY_VERSION
- FIL_PAGE_OFFSET)
+ ut_fold_binary(page + FIL_PAGE_DATA,
srv_page_size - FIL_PAGE_DATA
- FIL_PAGE_END_LSN_OLD_CHKSUM);
return(static_cast<uint32_t>(checksum));
}
/** In MySQL before 4.0.14 or 4.1.1 there was an InnoDB bug that
the checksum only looked at the first few bytes of the page.
This calculates that old checksum.
NOTE: we must first store the new formula checksum to
FIL_PAGE_SPACE_OR_CHKSUM before calculating and storing this old checksum
because this takes that field as an input!
@param[in] page file page (srv_page_size bytes)
@return checksum */
uint32_t
buf_calc_page_old_checksum(const byte* page)
{
return(static_cast<uint32_t>
(ut_fold_binary(page, FIL_PAGE_FILE_FLUSH_LSN_OR_KEY_VERSION)));
}
#endif /* !UNIV_INNOCHECKSUM */
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