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

Copyright (c) 1995, 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., 
51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA

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

/**************************************************//**
@file include/mtr0log.h
Mini-transaction logging routines

Created 12/7/1995 Heikki Tuuri
*******************************************************/

#ifndef mtr0log_h
#define mtr0log_h

#include "univ.i"
#include "mtr0mtr.h"
#include "dict0types.h"

#ifndef UNIV_HOTBACKUP
/********************************************************//**
Writes 1 - 4 bytes to a file page buffered in the buffer pool.
Writes the corresponding log record to the mini-transaction log. */
UNIV_INTERN
void
mlog_write_ulint(
/*=============*/
	byte*	ptr,	/*!< in: pointer where to write */
	ulint	val,	/*!< in: value to write */
	byte	type,	/*!< in: MLOG_1BYTE, MLOG_2BYTES, MLOG_4BYTES */
	mtr_t*	mtr);	/*!< in: mini-transaction handle */
/********************************************************//**
Writes 8 bytes to a file page buffered in the buffer pool.
Writes the corresponding log record to the mini-transaction log. */
UNIV_INTERN
void
mlog_write_ull(
/*===========*/
	byte*		ptr,	/*!< in: pointer where to write */
	ib_uint64_t	val,	/*!< in: value to write */
	mtr_t*		mtr);	/*!< in: mini-transaction handle */
/********************************************************//**
Writes a string to a file page buffered in the buffer pool. Writes the
corresponding log record to the mini-transaction log. */
UNIV_INTERN
void
mlog_write_string(
/*==============*/
	byte*		ptr,	/*!< in: pointer where to write */
	const byte*	str,	/*!< in: string to write */
	ulint		len,	/*!< in: string length */
	mtr_t*		mtr);	/*!< in: mini-transaction handle */
/********************************************************//**
Logs a write of a string to a file page buffered in the buffer pool.
Writes the corresponding log record to the mini-transaction log. */
UNIV_INTERN
void
mlog_log_string(
/*============*/
	byte*	ptr,	/*!< in: pointer written to */
	ulint	len,	/*!< in: string length */
	mtr_t*	mtr);	/*!< in: mini-transaction handle */
/********************************************************//**
Writes initial part of a log record consisting of one-byte item
type and four-byte space and page numbers. */
UNIV_INTERN
void
mlog_write_initial_log_record(
/*==========================*/
	const byte*	ptr,	/*!< in: pointer to (inside) a buffer
				frame holding the file page where
				modification is made */
	byte		type,	/*!< in: log item type: MLOG_1BYTE, ... */
	mtr_t*		mtr);	/*!< in: mini-transaction handle */
/********************************************************//**
Writes a log record about an .ibd file create/delete/rename.
@return	new value of log_ptr */
UNIV_INLINE
byte*
mlog_write_initial_log_record_for_file_op(
/*======================================*/
	ulint	type,	/*!< in: MLOG_FILE_CREATE, MLOG_FILE_DELETE, or
			MLOG_FILE_RENAME */
	ulint	space_id,/*!< in: space id, if applicable */
	ulint	page_no,/*!< in: page number (not relevant currently) */
	byte*	log_ptr,/*!< in: pointer to mtr log which has been opened */
	mtr_t*	mtr);	/*!< in: mtr */
/********************************************************//**
Catenates 1 - 4 bytes to the mtr log. */
UNIV_INLINE
void
mlog_catenate_ulint(
/*================*/
	mtr_t*	mtr,	/*!< in: mtr */
	ulint	val,	/*!< in: value to write */
	ulint	type);	/*!< in: MLOG_1BYTE, MLOG_2BYTES, MLOG_4BYTES */
/********************************************************//**
Catenates n bytes to the mtr log. */
UNIV_INTERN
void
mlog_catenate_string(
/*=================*/
	mtr_t*		mtr,	/*!< in: mtr */
	const byte*	str,	/*!< in: string to write */
	ulint		len);	/*!< in: string length */
/********************************************************//**
Catenates a compressed ulint to mlog. */
UNIV_INLINE
void
mlog_catenate_ulint_compressed(
/*===========================*/
	mtr_t*	mtr,	/*!< in: mtr */
	ulint	val);	/*!< in: value to write */
/********************************************************//**
Catenates a compressed 64-bit integer to mlog. */
UNIV_INLINE
void
mlog_catenate_ull_compressed(
/*=========================*/
	mtr_t*		mtr,	/*!< in: mtr */
	ib_uint64_t	val);	/*!< in: value to write */
/********************************************************//**
Opens a buffer to mlog. It must be closed with mlog_close.
@return	buffer, NULL if log mode MTR_LOG_NONE */
UNIV_INLINE
byte*
mlog_open(
/*======*/
	mtr_t*	mtr,	/*!< in: mtr */
	ulint	size);	/*!< in: buffer size in bytes; MUST be
			smaller than DYN_ARRAY_DATA_SIZE! */
/********************************************************//**
Closes a buffer opened to mlog. */
UNIV_INLINE
void
mlog_close(
/*=======*/
	mtr_t*	mtr,	/*!< in: mtr */
	byte*	ptr);	/*!< in: buffer space from ptr up was not used */
/********************************************************//**
Writes the initial part of a log record (3..11 bytes).
If the implementation of this function is changed, all
size parameters to mlog_open() should be adjusted accordingly!
@return	new value of log_ptr */
UNIV_INLINE
byte*
mlog_write_initial_log_record_fast(
/*===============================*/
	const byte*	ptr,	/*!< in: pointer to (inside) a buffer
				frame holding the file page where
				modification is made */
	byte		type,	/*!< in: log item type: MLOG_1BYTE, ... */
	byte*		log_ptr,/*!< in: pointer to mtr log which has
				been opened */
	mtr_t*		mtr);	/*!< in: mtr */
#else /* !UNIV_HOTBACKUP */
# define mlog_write_initial_log_record(ptr,type,mtr) ((void) 0)
# define mlog_write_initial_log_record_fast(ptr,type,log_ptr,mtr) ((byte *) 0)
#endif /* !UNIV_HOTBACKUP */
/********************************************************//**
Parses an initial log record written by mlog_write_initial_log_record.
@return	parsed record end, NULL if not a complete record */
UNIV_INTERN
byte*
mlog_parse_initial_log_record(
/*==========================*/
	byte*	ptr,	/*!< in: buffer */
	byte*	end_ptr,/*!< in: buffer end */
	byte*	type,	/*!< out: log record type: MLOG_1BYTE, ... */
	ulint*	space,	/*!< out: space id */
	ulint*	page_no);/*!< out: page number */
/********************************************************//**
Parses a log record written by mlog_write_ulint or mlog_write_ull.
@return	parsed record end, NULL if not a complete record */
UNIV_INTERN
byte*
mlog_parse_nbytes(
/*==============*/
	ulint	type,	/*!< in: log record type: MLOG_1BYTE, ... */
	byte*	ptr,	/*!< in: buffer */
	byte*	end_ptr,/*!< in: buffer end */
	byte*	page,	/*!< in: page where to apply the log record, or NULL */
	void*	page_zip);/*!< in/out: compressed page, or NULL */
/********************************************************//**
Parses a log record written by mlog_write_string.
@return	parsed record end, NULL if not a complete record */
UNIV_INTERN
byte*
mlog_parse_string(
/*==============*/
	byte*	ptr,	/*!< in: buffer */
	byte*	end_ptr,/*!< in: buffer end */
	byte*	page,	/*!< in: page where to apply the log record, or NULL */
	void*	page_zip);/*!< in/out: compressed page, or NULL */

#ifndef UNIV_HOTBACKUP
/********************************************************//**
Opens a buffer for mlog, writes the initial log record and,
if needed, the field lengths of an index.  Reserves space
for further log entries.  The log entry must be closed with
mtr_close().
@return	buffer, NULL if log mode MTR_LOG_NONE */
UNIV_INTERN
byte*
mlog_open_and_write_index(
/*======================*/
	mtr_t*		mtr,	/*!< in: mtr */
	const byte*	rec,	/*!< in: index record or page */
	dict_index_t*	index,	/*!< in: record descriptor */
	byte		type,	/*!< in: log item type */
	ulint		size);	/*!< in: requested buffer size in bytes
				(if 0, calls mlog_close() and returns NULL) */
#endif /* !UNIV_HOTBACKUP */

/********************************************************//**
Parses a log record written by mlog_open_and_write_index.
@return	parsed record end, NULL if not a complete record */
UNIV_INTERN
byte*
mlog_parse_index(
/*=============*/
	byte*		ptr,	/*!< in: buffer */
	const byte*	end_ptr,/*!< in: buffer end */
	ibool		comp,	/*!< in: TRUE=compact record format */
	dict_index_t**	index);	/*!< out, own: dummy index */

#ifndef UNIV_HOTBACKUP
/* Insert, update, and maybe other functions may use this value to define an
extra mlog buffer size for variable size data */
#define MLOG_BUF_MARGIN	256
#endif /* !UNIV_HOTBACKUP */

#ifndef UNIV_NONINL
#include "mtr0log.ic"
#endif

#endif
