/******************************************************
Mini-transaction buffer

(c) 1995 Innobase Oy

Created 11/26/1995 Heikki Tuuri
*******************************************************/

#ifndef mtr0mtr_h
#define mtr0mtr_h

#include "univ.i"
#include "mem0mem.h"
#include "dyn0dyn.h"
#include "buf0types.h"
#include "sync0rw.h"
#include "ut0byte.h"
#include "mtr0types.h"
#include "page0types.h"

/* Logging modes for a mini-transaction */
#define MTR_LOG_ALL		21	/* default mode: log all operations
					modifying disk-based data */
#define	MTR_LOG_NONE		22	/* log no operations */
/*#define	MTR_LOG_SPACE	23 */	/* log only operations modifying
					file space page allocation data
					(operations in fsp0fsp.* ) */
#define	MTR_LOG_SHORT_INSERTS	24	/* inserts are logged in a shorter
					form */
					
/* Types for the mlock objects to store in the mtr memo; NOTE that the
first 3 values must be RW_S_LATCH, RW_X_LATCH, RW_NO_LATCH */
#define	MTR_MEMO_PAGE_S_FIX	RW_S_LATCH
#define	MTR_MEMO_PAGE_X_FIX	RW_X_LATCH
#define	MTR_MEMO_BUF_FIX	RW_NO_LATCH
#define MTR_MEMO_MODIFY		54
#define	MTR_MEMO_S_LOCK		55
#define	MTR_MEMO_X_LOCK		56

/* Log item types: we have made them to be of the type 'byte'
for the compiler to warn if val and type parameters are switched
in a call to mlog_write_ulint. NOTE! For 1 - 8 bytes, the
flag value must give the length also! */
#define	MLOG_SINGLE_REC_FLAG	128		/* if the mtr contains only
						one log record for one page,
						i.e., write_initial_log_record
						has been called only once,
						this flag is ORed to the type
						of that first log record */
#define	MLOG_1BYTE		((byte)1) 	/* one byte is written */
#define	MLOG_2BYTES		((byte)2)	/* 2 bytes ... */
#define	MLOG_4BYTES		((byte)4)	/* 4 bytes ... */
#define	MLOG_8BYTES		((byte)8)	/* 8 bytes ... */
#define	MLOG_REC_INSERT		((byte)9)	/* record insert */
#define	MLOG_REC_CLUST_DELETE_MARK ((byte)10) 	/* mark clustered index record
						deleted */
#define	MLOG_REC_SEC_DELETE_MARK ((byte)11) 	/* mark secondary index record
						deleted */
#define MLOG_REC_UPDATE_IN_PLACE ((byte)13)	/* update of a record,
						preserves record field sizes */
#define MLOG_REC_DELETE		((byte)14)	/* delete a record from a
						page */
#define	MLOG_LIST_END_DELETE 	((byte)15)	/* delete record list end on
						index page */
#define	MLOG_LIST_START_DELETE 	((byte)16) 	/* delete record list start on
						index page */
#define	MLOG_LIST_END_COPY_CREATED ((byte)17) 	/* copy record list end to a
						new created index page */
#define	MLOG_PAGE_REORGANIZE 	((byte)18)	/* reorganize an index page */
#define MLOG_PAGE_CREATE 	((byte)19)	/* create an index page */
#define	MLOG_UNDO_INSERT 	((byte)20)	/* insert entry in an undo
						log */
#define MLOG_UNDO_ERASE_END	((byte)21)	/* erase an undo log page end */
#define	MLOG_UNDO_INIT 		((byte)22)	/* initialize a page in an
						undo log */
#define MLOG_UNDO_HDR_DISCARD	((byte)23)	/* discard an update undo log
						header */
#define	MLOG_UNDO_HDR_REUSE	((byte)24)	/* reuse an insert undo log
						header */
#define MLOG_UNDO_HDR_CREATE	((byte)25)	/* create an undo log header */
#define MLOG_REC_MIN_MARK	((byte)26)	/* mark an index record as the
						predefined minimum record */
#define MLOG_IBUF_BITMAP_INIT	((byte)27)	/* initialize an ibuf bitmap
						page */
#define	MLOG_FULL_PAGE		((byte)28)	/* full contents of a page */
#define MLOG_INIT_FILE_PAGE	((byte)29)	/* this means that a file page
						is taken into use and the prior
						contents of the page should be
						ignored: in recovery we must
						not trust the lsn values stored
						to the file page */
#define MLOG_WRITE_STRING	((byte)30)	/* write a string to a page */
#define	MLOG_MULTI_REC_END	((byte)31)	/* if a single mtr writes
						log records for several pages,
						this log record ends the
						sequence of these records */
#define MLOG_DUMMY_RECORD	((byte)32)	/* dummy log record used to
						pad a log block full */
#define MLOG_BIGGEST_TYPE	((byte)32) 	/* biggest value (used in
						asserts) */
					
/*******************************************************************
Starts a mini-transaction and creates a mini-transaction handle 
and buffer in the memory buffer given by the caller. */
UNIV_INLINE
mtr_t*
mtr_start(
/*======*/
			/* out: mtr buffer which also acts as
			the mtr handle */
	mtr_t*	mtr);	/* in: memory buffer for the mtr buffer */
/*******************************************************************
Starts a mini-transaction and creates a mini-transaction handle 
and buffer in the memory buffer given by the caller. */

mtr_t*
mtr_start_noninline(
/*================*/
			/* out: mtr buffer which also acts as
			the mtr handle */
	mtr_t*	mtr);	/* in: memory buffer for the mtr buffer */
/*******************************************************************
Commits a mini-transaction. */

void
mtr_commit(
/*=======*/
	mtr_t*	mtr);	/* in: mini-transaction */
/****************************************************************
Writes to the database log the full contents of the pages that this mtr is
the first to modify in the buffer pool. This function is called when the
database is in the online backup state. */

void
mtr_log_write_backup_entries(
/*=========================*/
	mtr_t*	mtr,		/* in: mini-transaction */
	dulint	backup_lsn);	/* in: online backup lsn */
/**************************************************************
Sets and returns a savepoint in mtr. */
UNIV_INLINE
ulint
mtr_set_savepoint(
/*==============*/
			/* out: savepoint */
	mtr_t*	mtr);	/* in: mtr */
/**************************************************************
Releases the latches stored in an mtr memo down to a savepoint.
NOTE! The mtr must not have made changes to buffer pages after the
savepoint, as these can be handled only by mtr_commit. */

void
mtr_rollback_to_savepoint(
/*======================*/
	mtr_t*	mtr,		/* in: mtr */
	ulint	savepoint);	/* in: savepoint */
/**************************************************************
Releases the (index tree) s-latch stored in an mtr memo after a
savepoint. */
UNIV_INLINE
void
mtr_release_s_latch_at_savepoint(
/*=============================*/
	mtr_t*		mtr,		/* in: mtr */
	ulint		savepoint,	/* in: savepoint */
	rw_lock_t* 	lock);		/* in: latch to release */
/*******************************************************************
Gets the logging mode of a mini-transaction. */
UNIV_INLINE
ulint
mtr_get_log_mode(
/*=============*/
			/* out: logging mode: MTR_LOG_NONE, ... */
	mtr_t*	mtr);	/* in: mtr */
/*******************************************************************
Changes the logging mode of a mini-transaction. */
UNIV_INLINE
ulint
mtr_set_log_mode(
/*=============*/
			/* out: old mode */
	mtr_t*	mtr,	/* in: mtr */
	ulint	mode);	/* in: logging mode: MTR_LOG_NONE, ... */
/************************************************************
Reads 1 - 4 bytes from a file page buffered in the buffer pool. */

ulint
mtr_read_ulint(
/*===========*/
			/* out: value read */
	byte*	ptr,	/* in: pointer from where to read */
	ulint	type,	/* in: MLOG_1BYTE, MLOG_2BYTES, MLOG_4BYTES */
	mtr_t*	mtr);	/* in: mini-transaction handle */
/************************************************************
Reads 8 bytes from a file page buffered in the buffer pool. */

dulint
mtr_read_dulint(
/*===========*/
			/* out: value read */
	byte*	ptr,	/* in: pointer from where to read */
	ulint	type,	/* in: MLOG_8BYTES */
	mtr_t*	mtr);	/* in: mini-transaction handle */
/*************************************************************************
This macro locks an rw-lock in s-mode. */
#ifdef UNIV_SYNC_DEBUG
#define mtr_s_lock(B, MTR)	mtr_s_lock_func((B), IB__FILE__, __LINE__,\
						(MTR))
#else
#define mtr_s_lock(B, MTR)	mtr_s_lock_func((B), (MTR))
#endif
/*************************************************************************
This macro locks an rw-lock in x-mode. */
#ifdef UNIV_SYNC_DEBUG
#define mtr_x_lock(B, MTR)	mtr_x_lock_func((B), IB__FILE__, __LINE__,\
						(MTR))
#else
#define mtr_x_lock(B, MTR)	mtr_x_lock_func((B), (MTR))
#endif
/*************************************************************************
NOTE! Use the macro above!
Locks a lock in s-mode. */
UNIV_INLINE
void
mtr_s_lock_func(
/*============*/
	rw_lock_t*	lock,	/* in: rw-lock */
#ifdef UNIV_SYNC_DEBUG
	char*		file,	/* in: file name */
	ulint		line,	/* in: line number */
#endif
	mtr_t*		mtr);	/* in: mtr */
/*************************************************************************
NOTE! Use the macro above!
Locks a lock in x-mode. */
UNIV_INLINE
void
mtr_x_lock_func(
/*============*/
	rw_lock_t*	lock,	/* in: rw-lock */
#ifdef UNIV_SYNC_DEBUG
	char*		file,	/* in: file name */
	ulint		line,	/* in: line number */
#endif
	mtr_t*		mtr);	/* in: mtr */

/*******************************************************
Releases an object in the memo stack. */

void
mtr_memo_release(
/*=============*/
	mtr_t*	mtr,	/* in: mtr */
	void*	object,	/* in: object */
	ulint	type);	/* in: object type: MTR_MEMO_S_LOCK, ... */
/****************************************************************
Parses a log record which contains the full contents of a page. */

byte*
mtr_log_parse_full_page(
/*====================*/
			/* out: end of log record or NULL */
	byte*	ptr,	/* in: buffer */
	byte*	end_ptr,/* in: buffer end */
	page_t*	page);	/* in: page or NULL */
/**************************************************************
Checks if memo contains the given item. */
UNIV_INLINE
ibool
mtr_memo_contains(
/*==============*/
			/* out: TRUE if contains */
	mtr_t*	mtr,	/* in: mtr */
	void*	object,	/* in: object to search */
	ulint	type);	/* in: type of object */
/*************************************************************
Prints info of an mtr handle. */

void
mtr_print(
/*======*/
	mtr_t*	mtr);	/* in: mtr */
/*######################################################################*/

#define	MTR_BUF_MEMO_SIZE	200	/* number of slots in memo */

/*******************************************************************
Returns the log object of a mini-transaction buffer. */
UNIV_INLINE
dyn_array_t*
mtr_get_log(
/*========*/
			/* out: log */
	mtr_t*	mtr);	/* in: mini-transaction */
/*******************************************************
Pushes an object to an mtr memo stack. */
UNIV_INLINE
void
mtr_memo_push(
/*==========*/
	mtr_t*	mtr,	/* in: mtr */
	void*	object,	/* in: object */
	ulint	type);	/* in: object type: MTR_MEMO_S_LOCK, ... */


/* Type definition of a mini-transaction memo stack slot. */
typedef	struct mtr_memo_slot_struct	mtr_memo_slot_t;
struct mtr_memo_slot_struct{
	ulint	type;	/* type of the stored object (MTR_MEMO_S_LOCK, ...) */
	void*	object;	/* pointer to the object */
};

/* Mini-transaction handle and buffer */
struct mtr_struct{
	ulint		state;	/* MTR_ACTIVE, MTR_COMMITTING, MTR_COMMITTED */
	dyn_array_t	memo;	/* memo stack for locks etc. */
	dyn_array_t	log;	/* mini-transaction log */
	ibool		modifications;
				/* TRUE if the mtr made modifications to
				buffer pool pages */
	ulint		n_log_recs;
				/* count of how many page initial log records
				have been written to the mtr log */
	ulint		log_mode; /* specifies which operations should be
				logged; default value MTR_LOG_ALL */
	dulint		start_lsn;/* start lsn of the possible log entry for
				this mtr */
	dulint		end_lsn;/* end lsn of the possible log entry for
				this mtr */
	ulint		magic_n;
};

#define	MTR_MAGIC_N		54551

#define MTR_ACTIVE		12231
#define MTR_COMMITTING		56456
#define MTR_COMMITTED		34676
	
#ifndef UNIV_NONINL
#include "mtr0mtr.ic"
#endif

#endif
