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

Copyright (c) 2006, 2023, Oracle and/or its affiliates.

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License, version 2.0,
as published by the Free Software Foundation.

This program is also distributed with certain software (including
but not limited to OpenSSL) that is licensed under separate terms,
as designated in a particular file or component or in included license
documentation.  The authors of MySQL hereby grant you an additional
permission to link the program and your derivative works with the
separately licensed software that they have included with MySQL.

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, version 2.0, 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/buf0buddy.ic
Binary buddy allocator for compressed pages

Created December 2006 by Marko Makela
*******************************************************/

#ifdef UNIV_MATERIALIZE
# undef UNIV_INLINE
# define UNIV_INLINE
#endif

#include "buf0buf.h"
#include "buf0buddy.h"

/**********************************************************************//**
Allocate a block.  The thread calling this function must hold
buf_pool->mutex and must not hold buf_pool->zip_mutex or any block->mutex.
The buf_pool_mutex may be released and reacquired.
@return allocated block, never NULL */
void*
buf_buddy_alloc_low(
/*================*/
	buf_pool_t*	buf_pool,	/*!< in/out: buffer pool instance */
	ulint		i,		/*!< in: index of buf_pool->zip_free[],
					or BUF_BUDDY_SIZES */
	ibool*		lru)		/*!< in: pointer to a variable that
					will be assigned TRUE if storage was
					allocated from the LRU list and
					buf_pool->mutex was temporarily
					released */
	MY_ATTRIBUTE((malloc));

/**********************************************************************//**
Deallocate a block. */
void
buf_buddy_free_low(
/*===============*/
	buf_pool_t*	buf_pool,	/*!< in: buffer pool instance */
	void*		buf,		/*!< in: block to be freed, must not be
					pointed to by the buffer pool */
	ulint		i);		/*!< in: index of buf_pool->zip_free[],
					or BUF_BUDDY_SIZES */

/**********************************************************************//**
Get the index of buf_pool->zip_free[] for a given block size.
@return index of buf_pool->zip_free[], or BUF_BUDDY_SIZES */
UNIV_INLINE
ulint
buf_buddy_get_slot(
/*===============*/
	ulint	size)	/*!< in: block size */
{
	ulint	i;
	ulint	s;

	ut_ad(size >= UNIV_ZIP_SIZE_MIN);

	for (i = 0, s = BUF_BUDDY_LOW; s < size; i++, s <<= 1) {
	}

	ut_ad(i <= BUF_BUDDY_SIZES);
	return(i);
}

/**********************************************************************//**
Allocate a block.  The thread calling this function must hold
buf_pool->mutex and must not hold buf_pool->zip_mutex or any
block->mutex.  The buf_pool->mutex may be released and reacquired.
This function should only be used for allocating compressed page frames.
@return allocated block, never NULL */
UNIV_INLINE
byte*
buf_buddy_alloc(
/*============*/
	buf_pool_t*	buf_pool,	/*!< in/out: buffer pool in which
					the page resides */
	ulint		size,		/*!< in: compressed page size
					(between UNIV_ZIP_SIZE_MIN and
					UNIV_PAGE_SIZE) */
	ibool*		lru)		/*!< in: pointer to a variable
					that will be assigned TRUE if
				       	storage was allocated from the
				       	LRU list and buf_pool->mutex was
				       	temporarily released */
{
	ut_ad(buf_pool_mutex_own(buf_pool));
	ut_ad(ut_is_2pow(size));
	ut_ad(size >= UNIV_ZIP_SIZE_MIN);
	ut_ad(size <= UNIV_PAGE_SIZE);

	return((byte*) buf_buddy_alloc_low(buf_pool, buf_buddy_get_slot(size),
					   lru));
}

/**********************************************************************//**
Deallocate a block. */
UNIV_INLINE
void
buf_buddy_free(
/*===========*/
	buf_pool_t*	buf_pool,	/*!< in/out: buffer pool in which
					the block resides */
	void*		buf,		/*!< in: block to be freed, must not
					be pointed to by the buffer pool */
	ulint		size)		/*!< in: block size,
					up to UNIV_PAGE_SIZE */
{
	ut_ad(buf_pool_mutex_own(buf_pool));
	ut_ad(ut_is_2pow(size));
	ut_ad(size >= UNIV_ZIP_SIZE_MIN);
	ut_ad(size <= UNIV_PAGE_SIZE);

	buf_buddy_free_low(buf_pool, buf, buf_buddy_get_slot(size));
}

#ifdef UNIV_MATERIALIZE
# undef UNIV_INLINE
# define UNIV_INLINE	UNIV_INLINE_ORIGINAL
#endif