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

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.ic
Mini-transaction logging routines

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

#include "mach0data.h"
#include "ut0lst.h"
#include "buf0buf.h"
#include "fsp0types.h"
#include "trx0sys.h"

/********************************************************//**
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! */
{
	dyn_array_t*	mlog;

	mtr->modifications = TRUE;

	if (mtr_get_log_mode(mtr) == MTR_LOG_NONE) {

		return(NULL);
	}

	mlog = &(mtr->log);

	return(dyn_array_open(mlog, 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 */
{
	dyn_array_t*	mlog;

	ut_ad(mtr_get_log_mode(mtr) != MTR_LOG_NONE);

	mlog = &(mtr->log);

	dyn_array_close(mlog, ptr);
}

#ifndef UNIV_HOTBACKUP
/********************************************************//**
Catenates 1 - 4 bytes to the mtr log. The value is not compressed. */
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 */
{
	dyn_array_t*	mlog;
	byte*		ptr;

	if (mtr_get_log_mode(mtr) == MTR_LOG_NONE) {

		return;
	}

	mlog = &(mtr->log);

#if MLOG_1BYTE != 1
# error "MLOG_1BYTE != 1"
#endif
#if MLOG_2BYTES != 2
# error "MLOG_2BYTES != 2"
#endif
#if MLOG_4BYTES != 4
# error "MLOG_4BYTES != 4"
#endif
#if MLOG_8BYTES != 8
# error "MLOG_8BYTES != 8"
#endif
	ptr = (byte*) dyn_array_push(mlog, type);

	if (type == MLOG_4BYTES) {
		mach_write_to_4(ptr, val);
	} else if (type == MLOG_2BYTES) {
		mach_write_to_2(ptr, val);
	} else {
		ut_ad(type == MLOG_1BYTE);
		mach_write_to_1(ptr, val);
	}
}

/********************************************************//**
Catenates a compressed ulint to mlog. */
UNIV_INLINE
void
mlog_catenate_ulint_compressed(
/*===========================*/
	mtr_t*	mtr,	/*!< in: mtr */
	ulint	val)	/*!< in: value to write */
{
	byte*	log_ptr;

	log_ptr = mlog_open(mtr, 10);

	/* If no logging is requested, we may return now */
	if (log_ptr == NULL) {

		return;
	}

	log_ptr += mach_write_compressed(log_ptr, val);

	mlog_close(mtr, log_ptr);
}

/********************************************************//**
Catenates a compressed dulint to mlog. */
UNIV_INLINE
void
mlog_catenate_dulint_compressed(
/*============================*/
	mtr_t*	mtr,	/*!< in: mtr */
	dulint	val)	/*!< in: value to write */
{
	byte*	log_ptr;

	log_ptr = mlog_open(mtr, 15);

	/* If no logging is requested, we may return now */
	if (log_ptr == NULL) {

		return;
	}

	log_ptr += mach_dulint_write_compressed(log_ptr, val);

	mlog_close(mtr, log_ptr);
}

/********************************************************//**
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 */
{
#ifdef UNIV_DEBUG
	buf_block_t*	block;
#endif
	const byte*	page;
	ulint		space;
	ulint		offset;

	ut_ad(mtr_memo_contains_page(mtr, ptr, MTR_MEMO_PAGE_X_FIX));
	ut_ad(type <= MLOG_BIGGEST_TYPE);
	ut_ad(ptr && log_ptr);

	page = (const byte*) ut_align_down(ptr, UNIV_PAGE_SIZE);
	space = mach_read_from_4(page + FIL_PAGE_ARCH_LOG_NO_OR_SPACE_ID);
	offset = mach_read_from_4(page + FIL_PAGE_OFFSET);

	/* check whether the page is in the doublewrite buffer;
	the doublewrite buffer is located in pages
	FSP_EXTENT_SIZE, ..., 3 * FSP_EXTENT_SIZE - 1 in the
	system tablespace */
	if (space == TRX_SYS_SPACE
	    && offset >= FSP_EXTENT_SIZE && offset < 3 * FSP_EXTENT_SIZE) {
		if (trx_doublewrite_buf_is_being_created) {
			/* Do nothing: we only come to this branch in an
			InnoDB database creation. We do not redo log
			anything for the doublewrite buffer pages. */
			return(log_ptr);
		} else {
			fprintf(stderr,
				"Error: trying to redo log a record of type "
				"%d on page %lu of space %lu in the "
				"doublewrite buffer, continuing anyway.\n"
				"Please post a bug report to "
				"bugs.mysql.com.\n",
				type, offset, space);
		}
	}

	mach_write_to_1(log_ptr, type);
	log_ptr++;
	log_ptr += mach_write_compressed(log_ptr, space);
	log_ptr += mach_write_compressed(log_ptr, offset);

	mtr->n_log_recs++;

#ifdef UNIV_LOG_DEBUG
	fprintf(stderr,
		"Adding to mtr log record type %lu space %lu page no %lu\n",
		(ulong) type, space, offset);
#endif

#ifdef UNIV_DEBUG
	/* We now assume that all x-latched pages have been modified! */
	block = (buf_block_t*) buf_block_align(ptr);

	if (!mtr_memo_contains(mtr, block, MTR_MEMO_MODIFY)) {

		mtr_memo_push(mtr, block, MTR_MEMO_MODIFY);
	}
#endif
	return(log_ptr);
}

/********************************************************//**
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 */
{
	ut_ad(log_ptr);

	mach_write_to_1(log_ptr, type);
	log_ptr++;

	/* We write dummy space id and page number */
	log_ptr += mach_write_compressed(log_ptr, space_id);
	log_ptr += mach_write_compressed(log_ptr, page_no);

	mtr->n_log_recs++;

	return(log_ptr);
}
#endif /* !UNIV_HOTBACKUP */