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

Copyright (c) 1995, 2011, Oracle and/or its affiliates. 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 Street, Suite 500, Boston, MA 02110-1335 USA

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

/**************************************************//**
@file include/fsp0fsp.ic
File space management

Created 12/18/1995 Heikki Tuuri
*******************************************************/

/***********************************************************************//**
Checks if a page address is an extent descriptor page address.
@return	TRUE if a descriptor page */
UNIV_INLINE
ibool
fsp_descr_page(
/*===========*/
	ulint	zip_size,/*!< in: compressed page size in bytes;
			0 for uncompressed pages */
	ulint	page_no)/*!< in: page number */
{
	ut_ad(ut_is_2pow(zip_size));

	if (!zip_size) {
		return(UNIV_UNLIKELY((page_no & (UNIV_PAGE_SIZE - 1))
				     == FSP_XDES_OFFSET));
	}

	return(UNIV_UNLIKELY((page_no & (zip_size - 1)) == FSP_XDES_OFFSET));
}
/********************************************************************//**
Extract the page size from tablespace flags.
This feature, storing the page_ssize into the tablespace flags, is added
to InnoDB 5.6.4.  This is here only to protect against a crash if a newer
database is opened with this code branch.
@return	page size of the tablespace in bytes */
UNIV_INLINE
ulint
fsp_flags_get_page_size(
/*====================*/
	ulint	flags)	/*!< in: tablespace flags */
{
	ulint	page_size = 0;
	ulint	ssize = FSP_FLAGS_GET_PAGE_SSIZE(flags);

	/* Convert from a 'log2 minus 9' to a page size in bytes. */
	if (UNIV_UNLIKELY(ssize)) {
		page_size = (512 << ssize);

		ut_ad(page_size <= UNIV_PAGE_SIZE);
	} else {
		/* If the page size was not stored, then it is the
		original 16k. */
		page_size = UNIV_PAGE_SIZE;
	}

	return(page_size);
}