/******************************************************
Data dictionary creation and booting

(c) 1996 Innobase Oy

Created 4/18/1996 Heikki Tuuri
*******************************************************/

/**************************************************************************
Writes the current value of the row id counter to the dictionary header file
page. */

void
dict_hdr_flush_row_id(void);
/*=======================*/


/**************************************************************************
Gets a pointer to the dictionary header and x-latches its page. */
UNIV_INLINE
dict_hdr_t*
dict_hdr_get(
/*=========*/
			/* out: pointer to the dictionary header, 
			page x-latched */
	mtr_t*	mtr)	/* in: mtr */
{
	dict_hdr_t*	header;

	ut_ad(mtr);
	
	header = DICT_HDR + buf_page_get(DICT_HDR_SPACE, DICT_HDR_PAGE_NO,
							RW_X_LATCH, mtr);
	buf_page_dbg_add_level(header, SYNC_DICT_HEADER);

	return(header);
}

/**************************************************************************
Returns a new table, index, or tree id. */
UNIV_INLINE
dulint
dict_hdr_get_new_id(
/*================*/
			/* out: the new id */
	ulint	type)	/* in: DICT_HDR_ROW_ID, ... */
{
	dict_hdr_t*	dict_hdr;
	dulint		id;
	mtr_t		mtr;

	ut_ad((type == DICT_HDR_TABLE_ID) || (type == DICT_HDR_INDEX_ID)
	      || (type == DICT_HDR_MIX_ID));

	mtr_start(&mtr);

	dict_hdr = dict_hdr_get(&mtr);

	id = mtr_read_dulint(dict_hdr + type, MLOG_8BYTES, &mtr); 

	id = ut_dulint_add(id, 1);
	
	mlog_write_dulint(dict_hdr + type, id, MLOG_8BYTES, &mtr); 

	mtr_commit(&mtr);

	return(id);
}				

/**************************************************************************
Returns a new row id. */
UNIV_INLINE
dulint
dict_sys_get_new_row_id(void)
/*=========================*/
			/* out: the new id */
{
	dulint	id;

	mutex_enter(&(dict_sys->mutex));

	id = dict_sys->row_id;
	
	if (0 == (ut_dulint_get_low(id) % DICT_HDR_ROW_ID_WRITE_MARGIN)) {

		dict_hdr_flush_row_id();
	}

	UT_DULINT_INC(dict_sys->row_id);

	mutex_exit(&(dict_sys->mutex));

	return(id);
}			

/**************************************************************************
Reads a row id from a record or other 6-byte stored form. */
UNIV_INLINE
dulint
dict_sys_read_row_id(
/*=================*/
			/* out: row id */
	byte*	field)	/* in: record field */
{
	ut_ad(DATA_ROW_ID_LEN == 6);

	return(mach_read_from_6(field));
}				

/**************************************************************************
Writes a row id to a record or other 6-byte stored form. */
UNIV_INLINE
void
dict_sys_write_row_id(
/*==================*/
	byte*	field,	/* in: record field */
	dulint	row_id)	/* in: row id */
{
	ut_ad(DATA_ROW_ID_LEN == 6);

	mach_write_to_6(field, row_id);
}