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

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
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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.,
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*****************************************************************************/

/**************************************************//**
@file include/buf0buddy.h
Binary buddy allocator for compressed pages

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

#ifndef buf0buddy_h
#define buf0buddy_h

#ifdef UNIV_MATERIALIZE
# undef UNIV_INLINE
# define UNIV_INLINE
#endif

#include "univ.i"
#include "buf0types.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.
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 */
	MY_ATTRIBUTE((malloc));

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

/** Reallocate a block.
@param[in]	buf_pool	buffer pool instance
@param[in]	buf		block to be reallocated, must be pointed
to by the buffer pool
@param[in]	size		block size, up to UNIV_PAGE_SIZE
@retval false	if failed because of no free blocks. */
bool
buf_buddy_realloc(
	buf_pool_t*	buf_pool,
	void*		buf,
	ulint		size);

/** Combine all pairs of free buddies.
@param[in]	buf_pool	buffer pool instance */
void
buf_buddy_condense_free(
	buf_pool_t*	buf_pool);

#ifndef UNIV_NONINL
# include "buf0buddy.ic"
#endif

#endif /* buf0buddy_h */