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Diffstat (limited to 'innobase/include/trx0purge.h')
| -rw-r--r-- | innobase/include/trx0purge.h | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/innobase/include/trx0purge.h b/innobase/include/trx0purge.h new file mode 100644 index 00000000000..8870ebc936c --- /dev/null +++ b/innobase/include/trx0purge.h @@ -0,0 +1,166 @@ +/****************************************************** +Purge old versions + +(c) 1996 Innobase Oy + +Created 3/26/1996 Heikki Tuuri +*******************************************************/ + +#ifndef trx0purge_h +#define trx0purge_h + +#include "univ.i" +#include "trx0types.h" +#include "mtr0mtr.h" +#include "trx0sys.h" +#include "que0types.h" +#include "page0page.h" +#include "usr0sess.h" +#include "fil0fil.h" + +/* The global data structure coordinating a purge */ +extern trx_purge_t* purge_sys; + +/* A dummy undo record used as a return value when we have a whole undo log +which needs no purge */ +extern trx_undo_rec_t trx_purge_dummy_rec; + +/************************************************************************ +Calculates the file address of an undo log header when we have the file +address of its history list node. */ +UNIV_INLINE +fil_addr_t +trx_purge_get_log_from_hist( +/*========================*/ + /* out: file address of the log */ + fil_addr_t node_addr); /* in: file address of the history + list node of the log */ +/********************************************************************* +Checks if trx_id is >= purge_view: then it is guaranteed that its update +undo log still exists in the system. */ + +ibool +trx_purge_update_undo_must_exist( +/*=============================*/ + /* out: TRUE if is sure that it is preserved, also + if the function returns FALSE, it is possible that + the undo log still exists in the system */ + dulint trx_id);/* in: transaction id */ +/************************************************************************ +Creates the global purge system control structure and inits the history +mutex. */ + +void +trx_purge_sys_create(void); +/*======================*/ +/************************************************************************ +Adds the update undo log as the first log in the history list. Removes the +update undo log segment from the rseg slot if it is too big for reuse. */ + +void +trx_purge_add_update_undo_to_history( +/*=================================*/ + trx_t* trx, /* in: transaction */ + page_t* undo_page, /* in: update undo log header page, + x-latched */ + mtr_t* mtr); /* in: mtr */ +/************************************************************************ +Fetches the next undo log record from the history list to purge. It must be +released with the corresponding release function. */ + +trx_undo_rec_t* +trx_purge_fetch_next_rec( +/*=====================*/ + /* out: copy of an undo log record, or + pointer to the dummy undo log record + &trx_purge_dummy_rec if the whole undo log + can skipped in purge; NULL if none left */ + dulint* roll_ptr,/* out: roll pointer to undo record */ + trx_undo_inf_t** cell, /* out: storage cell for the record in the + purge array */ + mem_heap_t* heap); /* in: memory heap where copied */ +/*********************************************************************** +Releases a reserved purge undo record. */ + +void +trx_purge_rec_release( +/*==================*/ + trx_undo_inf_t* cell); /* in: storage cell */ +/*********************************************************************** +This function runs a purge batch. */ + +ulint +trx_purge(void); +/*===========*/ + /* out: number of undo log pages handled in + the batch */ + +/* The control structure used in the purge operation */ +struct trx_purge_struct{ + ulint state; /* Purge system state */ + sess_t* sess; /* System session running the purge + query */ + trx_t* trx; /* System transaction running the purge + query: this trx is not in the trx list + of the trx system and it never ends */ + que_t* query; /* The query graph which will do the + parallelized purge operation */ + rw_lock_t purge_is_running;/* Purge operation set an x-latch here + while it is accessing a table: this + prevents dropping of the table */ + rw_lock_t latch; /* The latch protecting the purge view. + A purge operation must acquire an + x-latch here for the instant at which + it changes the purge view: an undo + log operation can prevent this by + obtaining an s-latch here. */ + read_view_t* view; /* The purge will not remove undo logs + which are >= this view (purge view) */ + mutex_t mutex; /* Mutex protecting the fields below */ + ulint n_pages_handled;/* Approximate number of undo log + pages processed in purge */ + ulint handle_limit; /* Target of how many pages to get + processed in the current purge */ + /*------------------------------*/ + /* The following two fields form the 'purge pointer' which advances + during a purge, and which is used in history list truncation */ + + dulint purge_trx_no; /* Purge has advanced past all + transactions whose number is less + than this */ + dulint purge_undo_no; /* Purge has advanced past all records + whose undo number is less than this */ + /*-----------------------------*/ + ibool next_stored; /* TRUE if the info of the next record + to purge is stored below: if yes, then + the transaction number and the undo + number of the record are stored in + purge_trx_no and purge_undo_no above */ + trx_rseg_t* rseg; /* Rollback segment for the next undo + record to purge */ + ulint page_no; /* Page number for the next undo + record to purge, page number of the + log header, if dummy record */ + ulint offset; /* Page offset for the next undo + record to purge, 0 if the dummy + record */ + ulint hdr_page_no; /* Header page of the undo log where + the next record to purge belongs */ + ulint hdr_offset; /* Header byte offset on the page */ + /*-----------------------------*/ + trx_undo_arr_t* arr; /* Array of transaction numbers and + undo numbers of the undo records + currently under processing in purge */ + mem_heap_t* heap; /* Temporary storage used during a + purge: can be emptied after purge + completes */ +}; + +#define TRX_PURGE_ON 1 /* purge operation is running */ +#define TRX_STOP_PURGE 2 /* purge operation is stopped, or + it should be stopped */ +#ifndef UNIV_NONINL +#include "trx0purge.ic" +#endif + +#endif |