diff options
Diffstat (limited to 'storage/innobase/include/trx0undo.h')
| -rw-r--r-- | storage/innobase/include/trx0undo.h | 560 |
1 files changed, 325 insertions, 235 deletions
diff --git a/storage/innobase/include/trx0undo.h b/storage/innobase/include/trx0undo.h index 7f10e407746..4a1e40af505 100644 --- a/storage/innobase/include/trx0undo.h +++ b/storage/innobase/include/trx0undo.h @@ -1,7 +1,24 @@ -/****************************************************** -Transaction undo log +/***************************************************************************** + +Copyright (c) 1996, 2012, Oracle and/or its affiliates. All Rights Reserved. + +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, Suite 500, Boston, MA 02110-1335 USA -(c) 1996 Innobase Oy +*****************************************************************************/ + +/**************************************************//** +@file include/trx0undo.h +Transaction undo log Created 3/26/1996 Heikki Tuuri *******************************************************/ @@ -16,37 +33,40 @@ Created 3/26/1996 Heikki Tuuri #include "page0types.h" #include "trx0xa.h" -/*************************************************************************** -Builds a roll pointer dulint. */ +#ifndef UNIV_HOTBACKUP +/***********************************************************************//** +Builds a roll pointer. +@return roll pointer */ UNIV_INLINE -dulint +roll_ptr_t trx_undo_build_roll_ptr( /*====================*/ - /* out: roll pointer */ - ibool is_insert, /* in: TRUE if insert undo log */ - ulint rseg_id, /* in: rollback segment id */ - ulint page_no, /* in: page number */ - ulint offset); /* in: offset of the undo entry within page */ -/*************************************************************************** -Decodes a roll pointer dulint. */ + ibool is_insert, /*!< in: TRUE if insert undo log */ + ulint rseg_id, /*!< in: rollback segment id */ + ulint page_no, /*!< in: page number */ + ulint offset); /*!< in: offset of the undo entry within page */ +/***********************************************************************//** +Decodes a roll pointer. */ UNIV_INLINE void trx_undo_decode_roll_ptr( /*=====================*/ - dulint roll_ptr, /* in: roll pointer */ - ibool* is_insert, /* out: TRUE if insert undo log */ - ulint* rseg_id, /* out: rollback segment id */ - ulint* page_no, /* out: page number */ - ulint* offset); /* out: offset of the undo entry within page */ -/*************************************************************************** -Returns TRUE if the roll pointer is of the insert type. */ + roll_ptr_t roll_ptr, /*!< in: roll pointer */ + ibool* is_insert, /*!< out: TRUE if insert undo log */ + ulint* rseg_id, /*!< out: rollback segment id */ + ulint* page_no, /*!< out: page number */ + ulint* offset); /*!< out: offset of the undo + entry within page */ +/***********************************************************************//** +Returns TRUE if the roll pointer is of the insert type. +@return TRUE if insert undo log */ UNIV_INLINE ibool trx_undo_roll_ptr_is_insert( /*========================*/ - /* out: TRUE if insert undo log */ - dulint roll_ptr); /* in: roll pointer */ -/********************************************************************* + roll_ptr_t roll_ptr); /*!< in: roll pointer */ +#endif /* !UNIV_HOTBACKUP */ +/*****************************************************************//** Writes a roll ptr to an index page. In case that the size changes in some future version, this function should be used instead of mach_write_... */ @@ -54,263 +74,314 @@ UNIV_INLINE void trx_write_roll_ptr( /*===============*/ - byte* ptr, /* in: pointer to memory where written */ - dulint roll_ptr); /* in: roll ptr */ -/********************************************************************* + byte* ptr, /*!< in: pointer to memory where + written */ + roll_ptr_t roll_ptr); /*!< in: roll ptr */ +/*****************************************************************//** Reads a roll ptr from an index page. In case that the roll ptr size changes in some future version, this function should be used instead of -mach_read_... */ +mach_read_... +@return roll ptr */ UNIV_INLINE -dulint +roll_ptr_t trx_read_roll_ptr( /*==============*/ - /* out: roll ptr */ - byte* ptr); /* in: pointer to memory from where to read */ -/********************************************************************** -Gets an undo log page and x-latches it. */ + const byte* ptr); /*!< in: pointer to memory from where to read */ +#ifndef UNIV_HOTBACKUP +/******************************************************************//** +Gets an undo log page and x-latches it. +@return pointer to page x-latched */ UNIV_INLINE page_t* trx_undo_page_get( /*==============*/ - /* out: pointer to page x-latched */ - ulint space, /* in: space where placed */ - ulint page_no, /* in: page number */ - mtr_t* mtr); /* in: mtr */ -/********************************************************************** -Gets an undo log page and s-latches it. */ + ulint space, /*!< in: space where placed */ + ulint zip_size, /*!< in: compressed page size in bytes + or 0 for uncompressed pages */ + ulint page_no, /*!< in: page number */ + mtr_t* mtr); /*!< in: mtr */ +/******************************************************************//** +Gets an undo log page and s-latches it. +@return pointer to page s-latched */ UNIV_INLINE page_t* trx_undo_page_get_s_latched( /*========================*/ - /* out: pointer to page s-latched */ - ulint space, /* in: space where placed */ - ulint page_no, /* in: page number */ - mtr_t* mtr); /* in: mtr */ -/********************************************************************** + ulint space, /*!< in: space where placed */ + ulint zip_size, /*!< in: compressed page size in bytes + or 0 for uncompressed pages */ + ulint page_no, /*!< in: page number */ + mtr_t* mtr); /*!< in: mtr */ +/******************************************************************//** Returns the previous undo record on the page in the specified log, or -NULL if none exists. */ +NULL if none exists. +@return pointer to record, NULL if none */ UNIV_INLINE trx_undo_rec_t* trx_undo_page_get_prev_rec( /*=======================*/ - /* out: pointer to record, NULL if none */ - trx_undo_rec_t* rec, /* in: undo log record */ - ulint page_no,/* in: undo log header page number */ - ulint offset);/* in: undo log header offset on page */ -/********************************************************************** + trx_undo_rec_t* rec, /*!< in: undo log record */ + ulint page_no,/*!< in: undo log header page number */ + ulint offset);/*!< in: undo log header offset on page */ +/******************************************************************//** Returns the next undo log record on the page in the specified log, or -NULL if none exists. */ +NULL if none exists. +@return pointer to record, NULL if none */ UNIV_INLINE trx_undo_rec_t* trx_undo_page_get_next_rec( /*=======================*/ - /* out: pointer to record, NULL if none */ - trx_undo_rec_t* rec, /* in: undo log record */ - ulint page_no,/* in: undo log header page number */ - ulint offset);/* in: undo log header offset on page */ -/********************************************************************** + trx_undo_rec_t* rec, /*!< in: undo log record */ + ulint page_no,/*!< in: undo log header page number */ + ulint offset);/*!< in: undo log header offset on page */ +/******************************************************************//** Returns the last undo record on the page in the specified undo log, or -NULL if none exists. */ +NULL if none exists. +@return pointer to record, NULL if none */ UNIV_INLINE trx_undo_rec_t* trx_undo_page_get_last_rec( /*=======================*/ - /* out: pointer to record, NULL if none */ - page_t* undo_page,/* in: undo log page */ - ulint page_no,/* in: undo log header page number */ - ulint offset); /* in: undo log header offset on page */ -/********************************************************************** + page_t* undo_page,/*!< in: undo log page */ + ulint page_no,/*!< in: undo log header page number */ + ulint offset); /*!< in: undo log header offset on page */ +/******************************************************************//** Returns the first undo record on the page in the specified undo log, or -NULL if none exists. */ +NULL if none exists. +@return pointer to record, NULL if none */ UNIV_INLINE trx_undo_rec_t* trx_undo_page_get_first_rec( /*========================*/ - /* out: pointer to record, NULL if none */ - page_t* undo_page,/* in: undo log page */ - ulint page_no,/* in: undo log header page number */ - ulint offset);/* in: undo log header offset on page */ -/*************************************************************************** -Gets the previous record in an undo log. */ - + page_t* undo_page,/*!< in: undo log page */ + ulint page_no,/*!< in: undo log header page number */ + ulint offset);/*!< in: undo log header offset on page */ +/***********************************************************************//** +Gets the previous record in an undo log. +@return undo log record, the page s-latched, NULL if none */ +UNIV_INTERN trx_undo_rec_t* trx_undo_get_prev_rec( /*==================*/ - /* out: undo log record, the page s-latched, - NULL if none */ - trx_undo_rec_t* rec, /* in: undo record */ - ulint page_no,/* in: undo log header page number */ - ulint offset, /* in: undo log header offset on page */ - mtr_t* mtr); /* in: mtr */ -/*************************************************************************** -Gets the next record in an undo log. */ - + trx_undo_rec_t* rec, /*!< in: undo record */ + ulint page_no,/*!< in: undo log header page number */ + ulint offset, /*!< in: undo log header offset on page */ + mtr_t* mtr); /*!< in: mtr */ +/***********************************************************************//** +Gets the next record in an undo log. +@return undo log record, the page s-latched, NULL if none */ +UNIV_INTERN trx_undo_rec_t* trx_undo_get_next_rec( /*==================*/ - /* out: undo log record, the page s-latched, - NULL if none */ - trx_undo_rec_t* rec, /* in: undo record */ - ulint page_no,/* in: undo log header page number */ - ulint offset, /* in: undo log header offset on page */ - mtr_t* mtr); /* in: mtr */ -/*************************************************************************** -Gets the first record in an undo log. */ - + trx_undo_rec_t* rec, /*!< in: undo record */ + ulint page_no,/*!< in: undo log header page number */ + ulint offset, /*!< in: undo log header offset on page */ + mtr_t* mtr); /*!< in: mtr */ +/***********************************************************************//** +Gets the first record in an undo log. +@return undo log record, the page latched, NULL if none */ +UNIV_INTERN trx_undo_rec_t* trx_undo_get_first_rec( /*===================*/ - /* out: undo log record, the page latched, NULL if - none */ - ulint space, /* in: undo log header space */ - ulint page_no,/* in: undo log header page number */ - ulint offset, /* in: undo log header offset on page */ - ulint mode, /* in: latching mode: RW_S_LATCH or RW_X_LATCH */ - mtr_t* mtr); /* in: mtr */ -/************************************************************************ -Tries to add a page to the undo log segment where the undo log is placed. */ - -ulint + ulint space, /*!< in: undo log header space */ + ulint zip_size,/*!< in: compressed page size in bytes + or 0 for uncompressed pages */ + ulint page_no,/*!< in: undo log header page number */ + ulint offset, /*!< in: undo log header offset on page */ + ulint mode, /*!< in: latching mode: RW_S_LATCH or RW_X_LATCH */ + mtr_t* mtr); /*!< in: mtr */ +/********************************************************************//** +Tries to add a page to the undo log segment where the undo log is placed. +@return X-latched block if success, else NULL */ +UNIV_INTERN +buf_block_t* trx_undo_add_page( /*==============*/ - /* out: page number if success, else - FIL_NULL */ - trx_t* trx, /* in: transaction */ - trx_undo_t* undo, /* in: undo log memory object */ - mtr_t* mtr); /* in: mtr which does not have a latch to any + trx_t* trx, /*!< in: transaction */ + trx_undo_t* undo, /*!< in: undo log memory object */ + mtr_t* mtr) /*!< in: mtr which does not have a latch to any undo log page; the caller must have reserved the rollback segment mutex */ -/*************************************************************************** + __attribute__((nonnull, warn_unused_result)); +/********************************************************************//** +Frees the last undo log page. +The caller must hold the rollback segment mutex. */ +UNIV_INTERN +void +trx_undo_free_last_page_func( +/*==========================*/ +#ifdef UNIV_DEBUG + const trx_t* trx, /*!< in: transaction */ +#endif /* UNIV_DEBUG */ + trx_undo_t* undo, /*!< in/out: undo log memory copy */ + mtr_t* mtr) /*!< in/out: mini-transaction which does not + have a latch to any undo log page or which + has allocated the undo log page */ + __attribute__((nonnull)); +#ifdef UNIV_DEBUG +# define trx_undo_free_last_page(trx,undo,mtr) \ + trx_undo_free_last_page_func(trx,undo,mtr) +#else /* UNIV_DEBUG */ +# define trx_undo_free_last_page(trx,undo,mtr) \ + trx_undo_free_last_page_func(undo,mtr) +#endif /* UNIV_DEBUG */ + +/***********************************************************************//** Truncates an undo log from the end. This function is used during a rollback to free space from an undo log. */ - +UNIV_INTERN void -trx_undo_truncate_end( -/*==================*/ - trx_t* trx, /* in: transaction whose undo log it is */ - trx_undo_t* undo, /* in: undo log */ - dulint limit); /* in: all undo records with undo number +trx_undo_truncate_end_func( +/*=======================*/ +#ifdef UNIV_DEBUG + const trx_t* trx, /*!< in: transaction whose undo log it is */ +#endif /* UNIV_DEBUG */ + trx_undo_t* undo, /*!< in/out: undo log */ + undo_no_t limit) /*!< in: all undo records with undo number >= this value should be truncated */ -/*************************************************************************** + __attribute__((nonnull)); +#ifdef UNIV_DEBUG +# define trx_undo_truncate_end(trx,undo,limit) \ + trx_undo_truncate_end_func(trx,undo,limit) +#else /* UNIV_DEBUG */ +# define trx_undo_truncate_end(trx,undo,limit) \ + trx_undo_truncate_end_func(undo,limit) +#endif /* UNIV_DEBUG */ + +/***********************************************************************//** Truncates an undo log from the start. This function is used during a purge operation. */ - +UNIV_INTERN void trx_undo_truncate_start( /*====================*/ - trx_rseg_t* rseg, /* in: rollback segment */ - ulint space, /* in: space id of the log */ - ulint hdr_page_no, /* in: header page number */ - ulint hdr_offset, /* in: header offset on the page */ - dulint limit); /* in: all undo pages with undo numbers < - this value should be truncated; NOTE that - the function only frees whole pages; the - header page is not freed, but emptied, if - all the records there are < limit */ -/************************************************************************ + trx_rseg_t* rseg, /*!< in: rollback segment */ + ulint space, /*!< in: space id of the log */ + ulint hdr_page_no, /*!< in: header page number */ + ulint hdr_offset, /*!< in: header offset on the page */ + undo_no_t limit); /*!< in: all undo pages with + undo numbers < this value + should be truncated; NOTE that + the function only frees whole + pages; the header page is not + freed, but emptied, if all the + records there are < limit */ +/********************************************************************//** Initializes the undo log lists for a rollback segment memory copy. This function is only called when the database is started or a new -rollback segment created. */ - +rollback segment created. +@return the combined size of undo log segments in pages */ +UNIV_INTERN ulint trx_undo_lists_init( /*================*/ - /* out: the combined size of undo log segments - in pages */ - trx_rseg_t* rseg); /* in: rollback segment memory object */ -/************************************************************************** + trx_rseg_t* rseg); /*!< in: rollback segment memory object */ +/**********************************************************************//** Assigns an undo log for a transaction. A new undo log is created or a cached -undo log reused. */ - +undo log reused. +@return DB_SUCCESS if undo log assign successful, possible error codes +are: DB_TOO_MANY_CONCURRENT_TRXS DB_OUT_OF_FILE_SPACE +DB_OUT_OF_MEMORY */ +UNIV_INTERN ulint trx_undo_assign_undo( /*=================*/ - /* out: DB_SUCCESS if undo log assign - * successful, possible error codes are: - * ER_TOO_MANY_CONCURRENT_TRXS - * DB_OUT_OF_FILE_SPAC - * DB_OUT_OF_MEMORY */ - trx_t* trx, /* in: transaction */ - ulint type); /* in: TRX_UNDO_INSERT or TRX_UNDO_UPDATE */ -/********************************************************************** -Sets the state of the undo log segment at a transaction finish. */ - + trx_t* trx, /*!< in: transaction */ + ulint type); /*!< in: TRX_UNDO_INSERT or TRX_UNDO_UPDATE */ +/******************************************************************//** +Sets the state of the undo log segment at a transaction finish. +@return undo log segment header page, x-latched */ +UNIV_INTERN page_t* trx_undo_set_state_at_finish( /*=========================*/ - /* out: undo log segment header page, - x-latched */ - trx_rseg_t* rseg, /* in: rollback segment memory object */ - trx_t* trx, /* in: transaction */ - trx_undo_t* undo, /* in: undo log memory copy */ - mtr_t* mtr); /* in: mtr */ -/********************************************************************** -Sets the state of the undo log segment at a transaction prepare. */ - + trx_undo_t* undo, /*!< in: undo log memory copy */ + mtr_t* mtr); /*!< in: mtr */ +/******************************************************************//** +Sets the state of the undo log segment at a transaction prepare. +@return undo log segment header page, x-latched */ +UNIV_INTERN page_t* trx_undo_set_state_at_prepare( /*==========================*/ - /* out: undo log segment header page, - x-latched */ - trx_t* trx, /* in: transaction */ - trx_undo_t* undo, /* in: undo log memory copy */ - mtr_t* mtr); /* in: mtr */ + trx_t* trx, /*!< in: transaction */ + trx_undo_t* undo, /*!< in: undo log memory copy */ + mtr_t* mtr); /*!< in: mtr */ -/************************************************************************** +/**********************************************************************//** Adds the update undo log header as the first in the history list, and frees the memory object, or puts it to the list of cached update undo log segments. */ - +UNIV_INTERN void trx_undo_update_cleanup( /*====================*/ - trx_t* trx, /* in: trx owning the update undo log */ - page_t* undo_page, /* in: update undo log header page, + trx_t* trx, /*!< in: trx owning the update undo log */ + page_t* undo_page, /*!< in: update undo log header page, x-latched */ - mtr_t* mtr); /* in: mtr */ -/********************************************************************** + mtr_t* mtr); /*!< in: mtr */ +/******************************************************************//** Frees or caches an insert undo log after a transaction commit or rollback. Knowledge of inserts is not needed after a commit or rollback, therefore the data can be discarded. */ - +UNIV_INTERN void trx_undo_insert_cleanup( /*====================*/ - trx_t* trx); /* in: transaction handle */ -/*************************************************************** -Parses the redo log entry of an undo log page initialization. */ + trx_t* trx); /*!< in: transaction handle */ +/********************************************************************//** +At shutdown, frees the undo logs of a PREPARED transaction. */ +UNIV_INTERN +void +trx_undo_free_prepared( +/*===================*/ + trx_t* trx) /*!< in/out: PREPARED transaction */ + UNIV_COLD __attribute__((nonnull)); +#endif /* !UNIV_HOTBACKUP */ +/***********************************************************//** +Parses the redo log entry of an undo log page initialization. +@return end of log record or NULL */ +UNIV_INTERN byte* trx_undo_parse_page_init( /*=====================*/ - /* out: end of log record or NULL */ - byte* ptr, /* in: buffer */ - byte* end_ptr,/* in: buffer end */ - page_t* page, /* in: page or NULL */ - mtr_t* mtr); /* in: mtr or NULL */ -/*************************************************************** -Parses the redo log entry of an undo log page header create or reuse. */ - + byte* ptr, /*!< in: buffer */ + byte* end_ptr,/*!< in: buffer end */ + page_t* page, /*!< in: page or NULL */ + mtr_t* mtr); /*!< in: mtr or NULL */ +/***********************************************************//** +Parses the redo log entry of an undo log page header create or reuse. +@return end of log record or NULL */ +UNIV_INTERN byte* trx_undo_parse_page_header( /*=======================*/ - /* out: end of log record or NULL */ - ulint type, /* in: MLOG_UNDO_HDR_CREATE or MLOG_UNDO_HDR_REUSE */ - byte* ptr, /* in: buffer */ - byte* end_ptr,/* in: buffer end */ - page_t* page, /* in: page or NULL */ - mtr_t* mtr); /* in: mtr or NULL */ -/*************************************************************** -Parses the redo log entry of an undo log page header discard. */ - + ulint type, /*!< in: MLOG_UNDO_HDR_CREATE or MLOG_UNDO_HDR_REUSE */ + byte* ptr, /*!< in: buffer */ + byte* end_ptr,/*!< in: buffer end */ + page_t* page, /*!< in: page or NULL */ + mtr_t* mtr); /*!< in: mtr or NULL */ +/***********************************************************//** +Parses the redo log entry of an undo log page header discard. +@return end of log record or NULL */ +UNIV_INTERN byte* trx_undo_parse_discard_latest( /*==========================*/ - /* out: end of log record or NULL */ - byte* ptr, /* in: buffer */ - byte* end_ptr,/* in: buffer end */ - page_t* page, /* in: page or NULL */ - mtr_t* mtr); /* in: mtr or NULL */ + byte* ptr, /*!< in: buffer */ + byte* end_ptr,/*!< in: buffer end */ + page_t* page, /*!< in: page or NULL */ + mtr_t* mtr); /*!< in: mtr or NULL */ +/************************************************************************ +Frees an undo log memory copy. */ +UNIV_INTERN +void +trx_undo_mem_free( +/*==============*/ + trx_undo_t* undo); /* in: the undo object to be freed */ /* Types of an undo log segment */ #define TRX_UNDO_INSERT 1 /* contains undo entries for inserts */ @@ -329,18 +400,19 @@ trx_undo_parse_discard_latest( #define TRX_UNDO_PREPARED 5 /* contains an undo log of an prepared transaction */ -/* Transaction undo log memory object; this is protected by the undo_mutex +#ifndef UNIV_HOTBACKUP +/** Transaction undo log memory object; this is protected by the undo_mutex in the corresponding transaction object */ struct trx_undo_struct{ /*-----------------------------*/ - ulint id; /* undo log slot number within the + ulint id; /*!< undo log slot number within the rollback segment */ - ulint type; /* TRX_UNDO_INSERT or + ulint type; /*!< TRX_UNDO_INSERT or TRX_UNDO_UPDATE */ - ulint state; /* state of the corresponding undo log + ulint state; /*!< state of the corresponding undo log segment */ - ibool del_marks; /* relevant only in an update undo log: + ibool del_marks; /*!< relevant only in an update undo log: this is TRUE if the transaction may have delete marked records, because of a delete of a row or an update of an @@ -348,65 +420,72 @@ struct trx_undo_struct{ necessary; also TRUE if the transaction has updated an externally stored field */ - dulint trx_id; /* id of the trx assigned to the undo + trx_id_t trx_id; /*!< id of the trx assigned to the undo log */ - XID xid; /* X/Open XA transaction + XID xid; /*!< X/Open XA transaction identification */ - ibool dict_operation; /* TRUE if a dict operation trx */ - dulint table_id; /* if a dict operation, then the table + ibool dict_operation; /*!< TRUE if a dict operation trx */ + table_id_t table_id; /*!< if a dict operation, then the table id */ - trx_rseg_t* rseg; /* rseg where the undo log belongs */ + trx_rseg_t* rseg; /*!< rseg where the undo log belongs */ /*-----------------------------*/ - ulint space; /* space id where the undo log + ulint space; /*!< space id where the undo log placed */ - ulint hdr_page_no; /* page number of the header page in + ulint zip_size; /*!< compressed page size of space + in bytes, or 0 for uncompressed */ + ulint hdr_page_no; /*!< page number of the header page in the undo log */ - ulint hdr_offset; /* header offset of the undo log on the + ulint hdr_offset; /*!< header offset of the undo log on the page */ - ulint last_page_no; /* page number of the last page in the + ulint last_page_no; /*!< page number of the last page in the undo log; this may differ from top_page_no during a rollback */ - ulint size; /* current size in pages */ + ulint size; /*!< current size in pages */ /*-----------------------------*/ - ulint empty; /* TRUE if the stack of undo log + ulint empty; /*!< TRUE if the stack of undo log records is currently empty */ - ulint top_page_no; /* page number where the latest undo + ulint top_page_no; /*!< page number where the latest undo log record was catenated; during rollback the page from which the latest undo record was chosen */ - ulint top_offset; /* offset of the latest undo record, + ulint top_offset; /*!< offset of the latest undo record, i.e., the topmost element in the undo log if we think of it as a stack */ - dulint top_undo_no; /* undo number of the latest record */ - page_t* guess_page; /* guess for the buffer frame where + undo_no_t top_undo_no; /*!< undo number of the latest record */ + buf_block_t* guess_block; /*!< guess for the buffer block where the top page might reside */ /*-----------------------------*/ UT_LIST_NODE_T(trx_undo_t) undo_list; - /* undo log objects in the rollback + /*!< undo log objects in the rollback segment are chained into lists */ }; +#endif /* !UNIV_HOTBACKUP */ -/* The offset of the undo log page header on pages of the undo log */ +/** The offset of the undo log page header on pages of the undo log */ #define TRX_UNDO_PAGE_HDR FSEG_PAGE_DATA /*-------------------------------------------------------------*/ -/* Transaction undo log page header offsets */ -#define TRX_UNDO_PAGE_TYPE 0 /* TRX_UNDO_INSERT or +/** Transaction undo log page header offsets */ +/* @{ */ +#define TRX_UNDO_PAGE_TYPE 0 /*!< TRX_UNDO_INSERT or TRX_UNDO_UPDATE */ -#define TRX_UNDO_PAGE_START 2 /* Byte offset where the undo log +#define TRX_UNDO_PAGE_START 2 /*!< Byte offset where the undo log records for the LATEST transaction start on this page (remember that in an update undo log, the first page can contain several undo logs) */ -#define TRX_UNDO_PAGE_FREE 4 /* On each page of the undo log this +#define TRX_UNDO_PAGE_FREE 4 /*!< On each page of the undo log this field contains the byte offset of the first free byte on the page */ -#define TRX_UNDO_PAGE_NODE 6 /* The file list node in the chain +#define TRX_UNDO_PAGE_NODE 6 /*!< The file list node in the chain of undo log pages */ /*-------------------------------------------------------------*/ #define TRX_UNDO_PAGE_HDR_SIZE (6 + FLST_NODE_SIZE) + /*!< Size of the transaction undo + log page header, in bytes */ +/* @} */ -/* An update undo segment with just one page can be reused if it has -< this number bytes used; we must leave space at least for one new undo +/** An update undo segment with just one page can be reused if it has +at most this many bytes used; we must leave space at least for one new undo log header on the page */ #define TRX_UNDO_PAGE_REUSE_LIMIT (3 * UNIV_PAGE_SIZE / 4) @@ -420,62 +499,67 @@ allowed to have zero undo records, but if the segment extends to several pages, then all the rest of the pages must contain at least one undo log record. */ -/* The offset of the undo log segment header on the first page of the undo +/** The offset of the undo log segment header on the first page of the undo log segment */ #define TRX_UNDO_SEG_HDR (TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_HDR_SIZE) +/** Undo log segment header */ +/* @{ */ /*-------------------------------------------------------------*/ -#define TRX_UNDO_STATE 0 /* TRX_UNDO_ACTIVE, ... */ -#define TRX_UNDO_LAST_LOG 2 /* Offset of the last undo log header +#define TRX_UNDO_STATE 0 /*!< TRX_UNDO_ACTIVE, ... */ +#define TRX_UNDO_LAST_LOG 2 /*!< Offset of the last undo log header on the segment header page, 0 if none */ -#define TRX_UNDO_FSEG_HEADER 4 /* Header for the file segment which +#define TRX_UNDO_FSEG_HEADER 4 /*!< Header for the file segment which the undo log segment occupies */ #define TRX_UNDO_PAGE_LIST (4 + FSEG_HEADER_SIZE) - /* Base node for the list of pages in + /*!< Base node for the list of pages in the undo log segment; defined only on the undo log segment's first page */ /*-------------------------------------------------------------*/ -/* Size of the undo log segment header */ +/** Size of the undo log segment header */ #define TRX_UNDO_SEG_HDR_SIZE (4 + FSEG_HEADER_SIZE + FLST_BASE_NODE_SIZE) +/* @} */ -/* The undo log header. There can be several undo log headers on the first +/** The undo log header. There can be several undo log headers on the first page of an update undo log segment. */ +/* @{ */ /*-------------------------------------------------------------*/ -#define TRX_UNDO_TRX_ID 0 /* Transaction id */ -#define TRX_UNDO_TRX_NO 8 /* Transaction number of the +#define TRX_UNDO_TRX_ID 0 /*!< Transaction id */ +#define TRX_UNDO_TRX_NO 8 /*!< Transaction number of the transaction; defined only if the log is in a history list */ -#define TRX_UNDO_DEL_MARKS 16 /* Defined only in an update undo +#define TRX_UNDO_DEL_MARKS 16 /*!< Defined only in an update undo log: TRUE if the transaction may have done delete markings of records, and thus purge is necessary */ -#define TRX_UNDO_LOG_START 18 /* Offset of the first undo log record +#define TRX_UNDO_LOG_START 18 /*!< Offset of the first undo log record of this log on the header page; purge may remove undo log record from the log start, and therefore this is not necessarily the same as this log header end offset */ -#define TRX_UNDO_XID_EXISTS 20 /* TRUE if undo log header includes +#define TRX_UNDO_XID_EXISTS 20 /*!< TRUE if undo log header includes X/Open XA transaction identification XID */ -#define TRX_UNDO_DICT_TRANS 21 /* TRUE if the transaction is a table +#define TRX_UNDO_DICT_TRANS 21 /*!< TRUE if the transaction is a table create, index create, or drop transaction: in recovery the transaction cannot be rolled back in the usual way: a 'rollback' rather means dropping the created or dropped table, if it still exists */ -#define TRX_UNDO_TABLE_ID 22 /* Id of the table if the preceding +#define TRX_UNDO_TABLE_ID 22 /*!< Id of the table if the preceding field is TRUE */ -#define TRX_UNDO_NEXT_LOG 30 /* Offset of the next undo log header +#define TRX_UNDO_NEXT_LOG 30 /*!< Offset of the next undo log header on this page, 0 if none */ -#define TRX_UNDO_PREV_LOG 32 /* Offset of the previous undo log +#define TRX_UNDO_PREV_LOG 32 /*!< Offset of the previous undo log header on this page, 0 if none */ -#define TRX_UNDO_HISTORY_NODE 34 /* If the log is put to the history +#define TRX_UNDO_HISTORY_NODE 34 /*!< If the log is put to the history list, the file list node is here */ /*-------------------------------------------------------------*/ +/** Size of the undo log header without XID information */ #define TRX_UNDO_LOG_OLD_HDR_SIZE (34 + FLST_NODE_SIZE) /* Note: the writing of the undo log old header is coded by a log record @@ -486,15 +570,21 @@ is not needed by the user. The XID wastes about 150 bytes of space in every undo log. In the history list we may have millions of undo logs, which means quite a large overhead. */ -/* X/Open XA Transaction Identification (XID) */ - +/** X/Open XA Transaction Identification (XID) */ +/* @{ */ +/** xid_t::formatID */ #define TRX_UNDO_XA_FORMAT (TRX_UNDO_LOG_OLD_HDR_SIZE) +/** xid_t::gtrid_length */ #define TRX_UNDO_XA_TRID_LEN (TRX_UNDO_XA_FORMAT + 4) +/** xid_t::bqual_length */ #define TRX_UNDO_XA_BQUAL_LEN (TRX_UNDO_XA_TRID_LEN + 4) +/** Distributed transaction identifier data */ #define TRX_UNDO_XA_XID (TRX_UNDO_XA_BQUAL_LEN + 4) /*--------------------------------------------------------------*/ #define TRX_UNDO_LOG_XA_HDR_SIZE (TRX_UNDO_XA_XID + XIDDATASIZE) - /* Total size of the header with the XA XID */ + /*!< Total size of the undo log header + with the XA XID */ +/* @} */ #ifndef UNIV_NONINL #include "trx0undo.ic" |