~drizzle-trunk/drizzle/development

/*****************************************************************************

Copyright (c) 1996, 2010, 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., 51 Franklin

St, Fifth Floor, Boston, MA 02110-1301 USA

*****************************************************************************/

/**************************************************//**

@file include/trx0sys.h

Transaction system

Created 3/26/1996 Heikki Tuuri

*******************************************************/

#ifndef trx0sys_h

#define trx0sys_h

#include "univ.i"

#include "trx0types.h"

#include "fsp0types.h"

#include "fil0fil.h"

#include "buf0buf.h"

#ifndef UNIV_HOTBACKUP

#include "mtr0mtr.h"

#include "ut0byte.h"

#include "mem0mem.h"

#include "sync0sync.h"

#include "ut0lst.h"

#include "read0types.h"

#include "page0types.h"

/** In a MySQL replication slave, in crash recovery we store the master log

file name and position here. */

/* @{ */

/** Master binlog file name */

extern char		trx_sys_mysql_master_log_name[];

/** Master binlog file position.  We have successfully got the updates

up to this position.  -1 means that no crash recovery was needed, or

there was no master log position info inside InnoDB.*/

extern ib_int64_t	trx_sys_mysql_master_log_pos;

/* @} */

/** If this MySQL server uses binary logging, after InnoDB has been inited

and if it has done a crash recovery, we store the binlog file name and position

here. */

/* @{ */

/** Binlog file name */

extern char		trx_sys_mysql_bin_log_name[];

/** Binlog file position, or -1 if unknown */

extern ib_int64_t	trx_sys_mysql_bin_log_pos;

/* @} */

/** The transaction system */

extern trx_sys_t*	trx_sys;

/** Doublewrite system */

extern trx_doublewrite_t*	trx_doublewrite;

/** The following is set to TRUE when we are upgrading from pre-4.1

format data files to the multiple tablespaces format data files */

extern ibool			trx_doublewrite_must_reset_space_ids;

/** Set to TRUE when the doublewrite buffer is being created */

extern ibool			trx_doublewrite_buf_is_being_created;

/** The following is TRUE when we are using the database in the

post-4.1 format, i.e., we have successfully upgraded, or have created

a new database installation */

extern ibool			trx_sys_multiple_tablespace_format;

/****************************************************************//**

Creates the doublewrite buffer to a new InnoDB installation. The header of the

doublewrite buffer is placed on the trx system header page. */

UNIV_INTERN

void

trx_sys_create_doublewrite_buf(void);

/*================================*/

/****************************************************************//**

At a database startup initializes the doublewrite buffer memory structure if

we already have a doublewrite buffer created in the data files. If we are

upgrading to an InnoDB version which supports multiple tablespaces, then this

function performs the necessary update operations. If we are in a crash

recovery, this function uses a possible doublewrite buffer to restore

half-written pages in the data files. */

UNIV_INTERN

void

trx_sys_doublewrite_init_or_restore_pages(

/*======================================*/

	ibool	restore_corrupt_pages);	/*!< in: TRUE=restore pages */

/****************************************************************//**

Marks the trx sys header when we have successfully upgraded to the >= 4.1.x

multiple tablespace format. */

UNIV_INTERN

void

trx_sys_mark_upgraded_to_multiple_tablespaces(void);

/*===============================================*/

/****************************************************************//**

Determines if a page number is located inside the doublewrite buffer.

@return TRUE if the location is inside the two blocks of the

doublewrite buffer */

UNIV_INTERN

ibool

trx_doublewrite_page_inside(

/*========================*/

	ulint	page_no);	/*!< in: page number */

/***************************************************************//**

Checks if a page address is the trx sys header page.

@return	TRUE if trx sys header page */

UNIV_INLINE

ibool

trx_sys_hdr_page(

/*=============*/

	ulint	space,	/*!< in: space */

	ulint	page_no);/*!< in: page number */

/*****************************************************************//**

Creates and initializes the central memory structures for the transaction

system. This is called when the database is started. */

UNIV_INTERN

void

trx_sys_init_at_db_start(void);

/*==========================*/

/*****************************************************************//**

Creates and initializes the transaction system at the database creation. */

UNIV_INTERN

void

trx_sys_create(void);

/*================*/

/****************************************************************//**

Looks for a free slot for a rollback segment in the trx system file copy.

@return	slot index or ULINT_UNDEFINED if not found */

UNIV_INTERN

ulint

trx_sysf_rseg_find_free(

/*====================*/

	mtr_t*		mtr);		/*!< in: mtr */

/***************************************************************//**

Gets the pointer in the nth slot of the rseg array.

@return	pointer to rseg object, NULL if slot not in use */

UNIV_INLINE

trx_rseg_t*

trx_sys_get_nth_rseg(

/*=================*/

	trx_sys_t*	sys,	/*!< in: trx system */

	ulint		n);	/*!< in: index of slot */

/***************************************************************//**

Sets the pointer in the nth slot of the rseg array. */

UNIV_INLINE

void

trx_sys_set_nth_rseg(

/*=================*/

	trx_sys_t*	sys,	/*!< in: trx system */

	ulint		n,	/*!< in: index of slot */

	trx_rseg_t*	rseg);	/*!< in: pointer to rseg object, NULL if slot

				not in use */

/**********************************************************************//**

Gets a pointer to the transaction system file copy and x-locks its page.

@return	pointer to system file copy, page x-locked */

UNIV_INLINE

trx_sysf_t*

trx_sysf_get(

/*=========*/

	mtr_t*	mtr);	/*!< in: mtr */

/*****************************************************************//**

Gets the space of the nth rollback segment slot in the trx system

file copy.

@return	space id */

UNIV_INLINE

ulint

trx_sysf_rseg_get_space(

/*====================*/

	trx_sysf_t*	sys_header,	/*!< in: trx sys file copy */

	ulint		i,		/*!< in: slot index == rseg id */

	mtr_t*		mtr);		/*!< in: mtr */

/*****************************************************************//**

Gets the page number of the nth rollback segment slot in the trx system

file copy.

@return	page number, FIL_NULL if slot unused */

UNIV_INLINE

ulint

trx_sysf_rseg_get_page_no(

/*======================*/

	trx_sysf_t*	sys_header,	/*!< in: trx sys file copy */

	ulint		i,		/*!< in: slot index == rseg id */

	mtr_t*		mtr);		/*!< in: mtr */

/*****************************************************************//**

Sets the space id of the nth rollback segment slot in the trx system

file copy. */

UNIV_INLINE

void

trx_sysf_rseg_set_space(

/*====================*/

	trx_sysf_t*	sys_header,	/*!< in: trx sys file copy */

	ulint		i,		/*!< in: slot index == rseg id */

	ulint		space,		/*!< in: space id */

	mtr_t*		mtr);		/*!< in: mtr */

/*****************************************************************//**

Sets the page number of the nth rollback segment slot in the trx system

file copy. */

UNIV_INLINE

void

trx_sysf_rseg_set_page_no(

/*======================*/

	trx_sysf_t*	sys_header,	/*!< in: trx sys file copy */

	ulint		i,		/*!< in: slot index == rseg id */

	ulint		page_no,	/*!< in: page number, FIL_NULL if

					the slot is reset to unused */

	mtr_t*		mtr);		/*!< in: mtr */

/*****************************************************************//**

Allocates a new transaction id.

@return	new, allocated trx id */

UNIV_INLINE

trx_id_t

trx_sys_get_new_trx_id(void);

/*========================*/

/*****************************************************************//**

Allocates a new transaction number.

@return	new, allocated trx number */

UNIV_INLINE

trx_id_t

trx_sys_get_new_trx_no(void);

/*========================*/

#endif /* !UNIV_HOTBACKUP */

/*****************************************************************//**

Writes a trx id to an index page. In case that the id size changes in

some future version, this function should be used instead of

mach_write_... */

UNIV_INLINE

void

trx_write_trx_id(

/*=============*/

	byte*		ptr,	/*!< in: pointer to memory where written */

	trx_id_t	id);	/*!< in: id */

#ifndef UNIV_HOTBACKUP

/*****************************************************************//**

Reads a trx id from an index page. In case that the id size changes in

some future version, this function should be used instead of

mach_read_...

@return	id */

UNIV_INLINE

trx_id_t

trx_read_trx_id(

/*============*/

	const byte*	ptr);	/*!< in: pointer to memory from where to read */

/****************************************************************//**

Looks for the trx handle with the given id in trx_list.

@return	the trx handle or NULL if not found */

UNIV_INLINE

trx_t*

trx_get_on_id(

/*==========*/

	trx_id_t	trx_id);/*!< in: trx id to search for */

/****************************************************************//**

Returns the minumum trx id in trx list. This is the smallest id for which

the trx can possibly be active. (But, you must look at the trx->conc_state to

find out if the minimum trx id transaction itself is active, or already

committed.)

@return	the minimum trx id, or trx_sys->max_trx_id if the trx list is empty */

UNIV_INLINE

trx_id_t

trx_list_get_min_trx_id(void);

/*=========================*/

/****************************************************************//**

Checks if a transaction with the given id is active.

@return	TRUE if active */

UNIV_INLINE

ibool

trx_is_active(

/*==========*/

	trx_id_t	trx_id);/*!< in: trx id of the transaction */

/****************************************************************//**

Checks that trx is in the trx list.

@return	TRUE if is in */

UNIV_INTERN

ibool

trx_in_trx_list(

/*============*/

	trx_t*	in_trx);/*!< in: trx */

/*****************************************************************//**

Updates the offset information about the end of the MySQL binlog entry

which corresponds to the transaction just being committed. In a MySQL

replication slave updates the latest master binlog position up to which

replication has proceeded. */

UNIV_INTERN

void

trx_sys_update_mysql_binlog_offset(

/*===============================*/

	const char*	file_name,/*!< in: MySQL log file name */

	ib_int64_t	offset,	/*!< in: position in that log file */

	ulint		field,	/*!< in: offset of the MySQL log info field in

				the trx sys header */

	mtr_t*		mtr);	/*!< in: mtr */

/*****************************************************************//**

Prints to stderr the MySQL binlog offset info in the trx system header if

the magic number shows it valid. */

UNIV_INTERN

void

trx_sys_print_mysql_binlog_offset(void);

/*===================================*/

/*****************************************************************//**

Prints to stderr the MySQL master log offset info in the trx system header if

the magic number shows it valid. */

UNIV_INTERN

void

trx_sys_print_mysql_master_log_pos(void);

/*====================================*/

/*****************************************************************//**

Initializes the tablespace tag system. */

UNIV_INTERN

void

trx_sys_file_format_init(void);

/*==========================*/

/*****************************************************************//**

Closes the tablespace tag system. */

UNIV_INTERN

void

trx_sys_file_format_close(void);

/*===========================*/

/********************************************************************//**

Tags the system table space with minimum format id if it has not been

tagged yet.

WARNING: This function is only called during the startup and AFTER the

redo log application during recovery has finished. */

UNIV_INTERN

void

trx_sys_file_format_tag_init(void);

/*==============================*/

#ifndef UNIV_HOTBACKUP

/*****************************************************************//**

Shutdown/Close the transaction system. */

UNIV_INTERN

void

trx_sys_close(void);

/*===============*/

#endif /* !UNIV_HOTBACKUP */

/*****************************************************************//**

Get the name representation of the file format from its id.

@return	pointer to the name */

UNIV_INTERN

const char*

trx_sys_file_format_id_to_name(

/*===========================*/

	const ulint	id);		/*!< in: id of the file format */

/*****************************************************************//**

Set the file format id unconditionally except if it's already the

same value.

@return	TRUE if value updated */

UNIV_INTERN

ibool

trx_sys_file_format_max_set(

/*========================*/

	ulint		format_id,	/*!< in: file format id */

	const char**	name);		/*!< out: max file format name or

					NULL if not needed. */

/*****************************************************************//**

Get the name representation of the file format from its id.

@return	pointer to the max format name */

UNIV_INTERN

const char*

trx_sys_file_format_max_get(void);

/*=============================*/

/*****************************************************************//**

Check for the max file format tag stored on disk.

@return	DB_SUCCESS or error code */

UNIV_INTERN

ulint

trx_sys_file_format_max_check(

/*==========================*/

	ulint		max_format_id);	/*!< in: the max format id to check */

/********************************************************************//**

Update the file format tag in the system tablespace only if the given

format id is greater than the known max id.

@return	TRUE if format_id was bigger than the known max id */

UNIV_INTERN

ibool

trx_sys_file_format_max_upgrade(

/*============================*/

	const char**	name,		/*!< out: max file format name */

	ulint		format_id);	/*!< in: file format identifier */

#else /* !UNIV_HOTBACKUP */

/*****************************************************************//**

Prints to stderr the MySQL binlog info in the system header if the

magic number shows it valid. */

UNIV_INTERN

void

trx_sys_print_mysql_binlog_offset_from_page(

/*========================================*/

	const byte*	page);	/*!< in: buffer containing the trx

				system header page, i.e., page number

				TRX_SYS_PAGE_NO in the tablespace */

/*****************************************************************//**

Reads the file format id from the first system table space file.

Even if the call succeeds and returns TRUE, the returned format id

may be ULINT_UNDEFINED signalling that the format id was not present

in the data file.

@return TRUE if call succeeds */

UNIV_INTERN

ibool

trx_sys_read_file_format_id(

/*========================*/

	const char *pathname,	/*!< in: pathname of the first system

				table space file */

	ulint *format_id);	/*!< out: file format of the system table

				space */

/*****************************************************************//**

Reads the file format id from the given per-table data file.

@return TRUE if call succeeds */

UNIV_INTERN

ibool

trx_sys_read_pertable_file_format_id(

/*=================================*/

	const char *pathname,	/*!< in: pathname of a per-table

				datafile */

	ulint *format_id);	/*!< out: file format of the per-table

				data file */

/*****************************************************************//**

Get the name representation of the file format from its id.

@return	pointer to the name */

UNIV_INTERN

const char*

trx_sys_file_format_id_to_name(

/*===========================*/

	const ulint	id);	/*!< in: id of the file format */

#endif /* !UNIV_HOTBACKUP */

/*********************************************************************

Creates the rollback segments */

UNIV_INTERN

void

trx_sys_create_rsegs(

/*=================*/

	ulint	n_rsegs);	/*!< number of rollback segments to create */

/* The automatically created system rollback segment has this id */

#define TRX_SYS_SYSTEM_RSEG_ID	0

/* Space id and page no where the trx system file copy resides */

#define	TRX_SYS_SPACE	0	/* the SYSTEM tablespace */

#include "fsp0fsp.h"

#define	TRX_SYS_PAGE_NO	FSP_TRX_SYS_PAGE_NO

/* The offset of the transaction system header on the page */

#define	TRX_SYS		FSEG_PAGE_DATA

/** Transaction system header */

/*------------------------------------------------------------- @{ */

#define	TRX_SYS_TRX_ID_STORE	0	/*!< the maximum trx id or trx

					number modulo

					TRX_SYS_TRX_ID_UPDATE_MARGIN

					written to a file page by any

					transaction; the assignment of

					transaction ids continues from

					this number rounded up by

					TRX_SYS_TRX_ID_UPDATE_MARGIN

					plus

					TRX_SYS_TRX_ID_UPDATE_MARGIN

					when the database is

					started */

#define TRX_SYS_FSEG_HEADER	8	/*!< segment header for the

					tablespace segment the trx

					system is created into */

#define	TRX_SYS_RSEGS		(8 + FSEG_HEADER_SIZE)

					/*!< the start of the array of

					rollback segment specification

					slots */

/*------------------------------------------------------------- @} */

/* Max number of rollback segments: the number of segment specification slots

in the transaction system array; rollback segment id must fit in one (signed)

byte, therefore 128; each slot is currently 8 bytes in size. If you want

to raise the level to 256 then you will need to fix some assertions that

impose the 7 bit restriction. e.g., mach_write_to_3() */

#define	TRX_SYS_N_RSEGS			128

/* Originally, InnoDB defined TRX_SYS_N_RSEGS as 256 but created only one

rollback segment.  It initialized some arrays with this number of entries.

We must remember this limit in order to keep file compatibility. */

#define TRX_SYS_OLD_N_RSEGS		256

/** Maximum length of MySQL binlog file name, in bytes.

@see trx_sys_mysql_master_log_name

@see trx_sys_mysql_bin_log_name */

#define TRX_SYS_MYSQL_LOG_NAME_LEN	512

/** Contents of TRX_SYS_MYSQL_LOG_MAGIC_N_FLD */

#define TRX_SYS_MYSQL_LOG_MAGIC_N	873422344

#if UNIV_PAGE_SIZE < 4096

# error "UNIV_PAGE_SIZE < 4096"

#endif

/** The offset of the MySQL replication info in the trx system header;

this contains the same fields as TRX_SYS_MYSQL_LOG_INFO below */

#define TRX_SYS_MYSQL_MASTER_LOG_INFO	(UNIV_PAGE_SIZE - 2000)

/** The offset of the MySQL binlog offset info in the trx system header */

#define TRX_SYS_MYSQL_LOG_INFO		(UNIV_PAGE_SIZE - 1000)

#define	TRX_SYS_MYSQL_LOG_MAGIC_N_FLD	0	/*!< magic number which is

						TRX_SYS_MYSQL_LOG_MAGIC_N

						if we have valid data in the

						MySQL binlog info */

#define TRX_SYS_MYSQL_LOG_OFFSET_HIGH	4	/*!< high 4 bytes of the offset

						within that file */

#define TRX_SYS_MYSQL_LOG_OFFSET_LOW	8	/*!< low 4 bytes of the offset

						within that file */

#define TRX_SYS_MYSQL_LOG_NAME		12	/*!< MySQL log file name */

/** Doublewrite buffer */

/* @{ */

/** The offset of the doublewrite buffer header on the trx system header page */

#define TRX_SYS_DOUBLEWRITE		(UNIV_PAGE_SIZE - 200)

/*-------------------------------------------------------------*/

#define TRX_SYS_DOUBLEWRITE_FSEG	0	/*!< fseg header of the fseg

						containing the doublewrite

						buffer */

#define TRX_SYS_DOUBLEWRITE_MAGIC	FSEG_HEADER_SIZE

						/*!< 4-byte magic number which

						shows if we already have

						created the doublewrite

						buffer */

#define TRX_SYS_DOUBLEWRITE_BLOCK1	(4 + FSEG_HEADER_SIZE)

						/*!< page number of the

						first page in the first

						sequence of 64

						(= FSP_EXTENT_SIZE) consecutive

						pages in the doublewrite

						buffer */

#define TRX_SYS_DOUBLEWRITE_BLOCK2	(8 + FSEG_HEADER_SIZE)

						/*!< page number of the

						first page in the second

						sequence of 64 consecutive

						pages in the doublewrite

						buffer */

#define TRX_SYS_DOUBLEWRITE_REPEAT	12	/*!< we repeat

						TRX_SYS_DOUBLEWRITE_MAGIC,

						TRX_SYS_DOUBLEWRITE_BLOCK1,

						TRX_SYS_DOUBLEWRITE_BLOCK2

						so that if the trx sys

						header is half-written

						to disk, we still may

						be able to recover the

						information */

/** If this is not yet set to TRX_SYS_DOUBLEWRITE_SPACE_ID_STORED_N,

we must reset the doublewrite buffer, because starting from 4.1.x the

space id of a data page is stored into

FIL_PAGE_ARCH_LOG_NO_OR_SPACE_NO. */

#define TRX_SYS_DOUBLEWRITE_SPACE_ID_STORED (24 + FSEG_HEADER_SIZE)

/*-------------------------------------------------------------*/

/** Contents of TRX_SYS_DOUBLEWRITE_MAGIC */

#define TRX_SYS_DOUBLEWRITE_MAGIC_N	536853855

/** Contents of TRX_SYS_DOUBLEWRITE_SPACE_ID_STORED */

#define TRX_SYS_DOUBLEWRITE_SPACE_ID_STORED_N 1783657386

/** Size of the doublewrite block in pages */

#define TRX_SYS_DOUBLEWRITE_BLOCK_SIZE	FSP_EXTENT_SIZE

/* @} */

#ifndef UNIV_HOTBACKUP

/** File format tag */

/* @{ */

/** The offset of the file format tag on the trx system header page

(TRX_SYS_PAGE_NO of TRX_SYS_SPACE) */

#define TRX_SYS_FILE_FORMAT_TAG		(UNIV_PAGE_SIZE - 16)

/** Contents of TRX_SYS_FILE_FORMAT_TAG when valid. The file format

identifier is added to this constant. */

#define TRX_SYS_FILE_FORMAT_TAG_MAGIC_N_LOW	3645922177UL

/** Contents of TRX_SYS_FILE_FORMAT_TAG+4 when valid */

#define TRX_SYS_FILE_FORMAT_TAG_MAGIC_N_HIGH	2745987765UL

/** Contents of TRX_SYS_FILE_FORMAT_TAG when valid. The file format

identifier is added to this 64-bit constant. */

#define TRX_SYS_FILE_FORMAT_TAG_MAGIC_N					\

	((ib_uint64_t) TRX_SYS_FILE_FORMAT_TAG_MAGIC_N_HIGH << 32	\

	 | TRX_SYS_FILE_FORMAT_TAG_MAGIC_N_LOW)

/* @} */

/** Doublewrite control struct */

struct trx_doublewrite_struct{

	mutex_t	mutex;		/*!< mutex protecting the first_free field and

				write_buf */

	ulint	block1;		/*!< the page number of the first

				doublewrite block (64 pages) */

	ulint	block2;		/*!< page number of the second block */

	ulint	first_free;	/*!< first free position in write_buf measured

				in units of UNIV_PAGE_SIZE */

	byte*	write_buf;	/*!< write buffer used in writing to the

				doublewrite buffer, aligned to an

				address divisible by UNIV_PAGE_SIZE

				(which is required by Windows aio) */

	byte*	write_buf_unaligned;

				/*!< pointer to write_buf, but unaligned */

	buf_page_t**

		buf_block_arr;	/*!< array to store pointers to the buffer

				blocks which have been cached to write_buf */

};

/** The transaction system central memory data structure; protected by the

kernel mutex */

struct trx_sys_struct{

	trx_id_t	max_trx_id;	/*!< The smallest number not yet

					assigned as a transaction id or

					transaction number */

	UT_LIST_BASE_NODE_T(trx_t) trx_list;

					/*!< List of active and committed in

					memory transactions, sorted on trx id,

					biggest first */

	UT_LIST_BASE_NODE_T(trx_t) mysql_trx_list;

					/*!< List of transactions created

					for MySQL */

	UT_LIST_BASE_NODE_T(trx_rseg_t) rseg_list;

					/*!< List of rollback segment

					objects */

	trx_rseg_t*	latest_rseg;	/*!< Latest rollback segment in the

					round-robin assignment of rollback

					segments to transactions */

	trx_rseg_t*	rseg_array[TRX_SYS_N_RSEGS];

					/*!< Pointer array to rollback

					segments; NULL if slot not in use */

	ulint		rseg_history_len;/*!< Length of the TRX_RSEG_HISTORY

					list (update undo logs for committed

					transactions), protected by

					rseg->mutex */

	UT_LIST_BASE_NODE_T(read_view_t) view_list;

					/*!< List of read views sorted

					on trx no, biggest first */

};

/** When a trx id which is zero modulo this number (which must be a power of

two) is assigned, the field TRX_SYS_TRX_ID_STORE on the transaction system

page is updated */

#define TRX_SYS_TRX_ID_WRITE_MARGIN	256

#endif /* !UNIV_HOTBACKUP */

#ifndef UNIV_NONINL

#include "trx0sys.ic"

#endif

#endif