mariadb/include/trx0i_s.h
2010-01-06 04:00:14 -08:00

247 lines
8.3 KiB
C

/*****************************************************************************
Copyright (c) 2007, 2009, Innobase Oy. 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., 59 Temple
Place, Suite 330, Boston, MA 02111-1307 USA
*****************************************************************************/
/**************************************************//**
@file include/trx0i_s.h
INFORMATION SCHEMA innodb_trx, innodb_locks and
innodb_lock_waits tables cache structures and public
functions.
Created July 17, 2007 Vasil Dimov
*******************************************************/
#ifndef trx0i_s_h
#define trx0i_s_h
#include "univ.i"
#include "trx0types.h"
#include "ut0ut.h"
/** The maximum amount of memory that can be consumed by innodb_trx,
innodb_locks and innodb_lock_waits information schema tables. */
#define TRX_I_S_MEM_LIMIT 16777216 /* 16 MiB */
/** The maximum length of a string that can be stored in
i_s_locks_row_t::lock_data */
#define TRX_I_S_LOCK_DATA_MAX_LEN 8192
/** The maximum length of a string that can be stored in
i_s_trx_row_t::trx_query */
#define TRX_I_S_TRX_QUERY_MAX_LEN 1024
/** A row of INFORMATION_SCHEMA.innodb_locks */
typedef struct i_s_locks_row_struct i_s_locks_row_t;
/** A row of INFORMATION_SCHEMA.innodb_trx */
typedef struct i_s_trx_row_struct i_s_trx_row_t;
/** A row of INFORMATION_SCHEMA.innodb_lock_waits */
typedef struct i_s_lock_waits_row_struct i_s_lock_waits_row_t;
/** Objects of trx_i_s_cache_t::locks_hash */
typedef struct i_s_hash_chain_struct i_s_hash_chain_t;
/** Objects of this type are added to the hash table
trx_i_s_cache_t::locks_hash */
struct i_s_hash_chain_struct {
i_s_locks_row_t* value; /*!< row of
INFORMATION_SCHEMA.innodb_locks*/
i_s_hash_chain_t* next; /*!< next item in the hash chain */
};
/** This structure represents INFORMATION_SCHEMA.innodb_locks row */
struct i_s_locks_row_struct {
ullint lock_trx_id; /*!< transaction identifier */
const char* lock_mode; /*!< lock mode from
lock_get_mode_str() */
const char* lock_type; /*!< lock type from
lock_get_type_str() */
const char* lock_table; /*!< table name from
lock_get_table_name() */
const char* lock_index; /*!< index name from
lock_rec_get_index_name() */
/** Information for record locks. All these are
ULINT_UNDEFINED for table locks. */
/* @{ */
ulint lock_space; /*!< tablespace identifier */
ulint lock_page; /*!< page number within the_space */
ulint lock_rec; /*!< heap number of the record
on the page */
const char* lock_data; /*!< (some) content of the record */
/* @} */
/** The following are auxiliary and not included in the table */
/* @{ */
ullint lock_table_id;
/*!< table identifier from
lock_get_table_id */
i_s_hash_chain_t hash_chain; /*!< hash table chain node for
trx_i_s_cache_t::locks_hash */
/* @} */
};
/** This structure represents INFORMATION_SCHEMA.innodb_trx row */
struct i_s_trx_row_struct {
ullint trx_id; /*!< transaction identifier */
const char* trx_state; /*!< transaction state from
trx_get_que_state_str() */
ib_time_t trx_started; /*!< trx_struct::start_time */
const i_s_locks_row_t* requested_lock_row;
/*!< pointer to a row
in innodb_locks if trx
is waiting, or NULL */
ib_time_t trx_wait_started;
/*!< trx_struct::wait_started */
ullint trx_weight; /*!< TRX_WEIGHT() */
ulint trx_mysql_thread_id;
/*!< thd_get_thread_id() */
const char* trx_query; /*!< MySQL statement being
executed in the transaction */
};
/** This structure represents INFORMATION_SCHEMA.innodb_lock_waits row */
struct i_s_lock_waits_row_struct {
const i_s_locks_row_t* requested_lock_row; /*!< requested lock */
const i_s_locks_row_t* blocking_lock_row; /*!< blocking lock */
};
/** Cache of INFORMATION_SCHEMA table data */
typedef struct trx_i_s_cache_struct trx_i_s_cache_t;
/** Auxiliary enum used by functions that need to select one of the
INFORMATION_SCHEMA tables */
enum i_s_table {
I_S_INNODB_TRX, /*!< INFORMATION_SCHEMA.innodb_trx */
I_S_INNODB_LOCKS, /*!< INFORMATION_SCHEMA.innodb_locks */
I_S_INNODB_LOCK_WAITS /*!< INFORMATION_SCHEMA.innodb_lock_waits */
};
/** This is the intermediate buffer where data needed to fill the
INFORMATION SCHEMA tables is fetched and later retrieved by the C++
code in handler/i_s.cc. */
extern trx_i_s_cache_t* trx_i_s_cache;
/*******************************************************************//**
Initialize INFORMATION SCHEMA trx related cache. */
UNIV_INTERN
void
trx_i_s_cache_init(
/*===============*/
trx_i_s_cache_t* cache); /*!< out: cache to init */
/*******************************************************************//**
Free the INFORMATION SCHEMA trx related cache. */
UNIV_INTERN
void
trx_i_s_cache_free(
/*===============*/
trx_i_s_cache_t* cache); /*!< in/out: cache to free */
/*******************************************************************//**
Issue a shared/read lock on the tables cache. */
UNIV_INTERN
void
trx_i_s_cache_start_read(
/*=====================*/
trx_i_s_cache_t* cache); /*!< in: cache */
/*******************************************************************//**
Release a shared/read lock on the tables cache. */
UNIV_INTERN
void
trx_i_s_cache_end_read(
/*===================*/
trx_i_s_cache_t* cache); /*!< in: cache */
/*******************************************************************//**
Issue an exclusive/write lock on the tables cache. */
UNIV_INTERN
void
trx_i_s_cache_start_write(
/*======================*/
trx_i_s_cache_t* cache); /*!< in: cache */
/*******************************************************************//**
Release an exclusive/write lock on the tables cache. */
UNIV_INTERN
void
trx_i_s_cache_end_write(
/*====================*/
trx_i_s_cache_t* cache); /*!< in: cache */
/*******************************************************************//**
Retrieves the number of used rows in the cache for a given
INFORMATION SCHEMA table.
@return number of rows */
UNIV_INTERN
ulint
trx_i_s_cache_get_rows_used(
/*========================*/
trx_i_s_cache_t* cache, /*!< in: cache */
enum i_s_table table); /*!< in: which table */
/*******************************************************************//**
Retrieves the nth row in the cache for a given INFORMATION SCHEMA
table.
@return row */
UNIV_INTERN
void*
trx_i_s_cache_get_nth_row(
/*======================*/
trx_i_s_cache_t* cache, /*!< in: cache */
enum i_s_table table, /*!< in: which table */
ulint n); /*!< in: row number */
/*******************************************************************//**
Update the transactions cache if it has not been read for some time.
@return 0 - fetched, 1 - not */
UNIV_INTERN
int
trx_i_s_possibly_fetch_data_into_cache(
/*===================================*/
trx_i_s_cache_t* cache); /*!< in/out: cache */
/*******************************************************************//**
Returns TRUE if the data in the cache is truncated due to the memory
limit posed by TRX_I_S_MEM_LIMIT.
@return TRUE if truncated */
UNIV_INTERN
ibool
trx_i_s_cache_is_truncated(
/*=======================*/
trx_i_s_cache_t* cache); /*!< in: cache */
/** The maximum length of a resulting lock_id_size in
trx_i_s_create_lock_id(), not including the terminating NUL.
":%lu:%lu:%lu" -> 63 chars */
#define TRX_I_S_LOCK_ID_MAX_LEN (TRX_ID_MAX_LEN + 63)
/*******************************************************************//**
Crafts a lock id string from a i_s_locks_row_t object. Returns its
second argument. This function aborts if there is not enough space in
lock_id. Be sure to provide at least TRX_I_S_LOCK_ID_MAX_LEN + 1 if you
want to be 100% sure that it will not abort.
@return resulting lock id */
UNIV_INTERN
char*
trx_i_s_create_lock_id(
/*===================*/
const i_s_locks_row_t* row, /*!< in: innodb_locks row */
char* lock_id,/*!< out: resulting lock_id */
ulint lock_id_size);/*!< in: size of the lock id
buffer */
#endif /* trx0i_s_h */