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Diffstat (limited to '')
| -rw-r--r-- | storage/innobase/buf/buf0checksum.cc | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/storage/innobase/buf/buf0checksum.cc b/storage/innobase/buf/buf0checksum.cc new file mode 100644 index 00000000..662343ae --- /dev/null +++ b/storage/innobase/buf/buf0checksum.cc @@ -0,0 +1,98 @@ +/***************************************************************************** + +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 */ |