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

Copyright (c) 2006, 2016, 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/buf0buddy.h
Binary buddy allocator for compressed pages

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

#ifndef buf0buddy_h
#define buf0buddy_h

#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
					srv_page_size) */
	bool*		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, nonnull));

/**********************************************************************//**
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 srv_page_size */
	MY_ATTRIBUTE((nonnull));

/** 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 srv_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);

#include "buf0buddy.ic"

#endif /* buf0buddy_h */
