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

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

/** @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 "buf0buddy.h"
#include "buf0buf.h"

/** Allocate a block.
@param[in,out]	buf_pool	buffer pool instance
@param[in]	i		index of buf_pool->zip_free[]
                                or BUF_BUDDY_SIZES
@return allocated block, never NULL */
void *buf_buddy_alloc_low(buf_pool_t *buf_pool, ulint i) MY_ATTRIBUTE((malloc));

/** Deallocate a block.
@param[in]	buf_pool	buffer pool instance
@param[in]	buf		block to be freed, must not be pointed to
                                by the buffer pool
@param[in]	i		index of buf_pool->zip_free[],
                                or BUF_BUDDY_SIZES
@param[in]	has_zip_free	whether has zip_free_mutex */
void buf_buddy_free_low(buf_pool_t *buf_pool, void *buf, ulint i,
                        bool has_zip_free);

/** 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. This function should only be used for allocating
compressed page frames. The thread calling this function must hold
buf_pool->LRU_list_mutex and must not hold buf_pool->zip_mutex or any
block->mutex.
@param[in,out]	buf_pool	buffer pool in which the page resides
@param[in]	size		compressed page size, between
                                UNIV_ZIP_SIZE_MIN and UNIV_PAGE_SIZE
@return allocated block, never NULL */
UNIV_INLINE
byte *buf_buddy_alloc(buf_pool_t *buf_pool, ulint size) {
  ut_ad(ut_is_2pow(size));
  ut_ad(size >= UNIV_ZIP_SIZE_MIN);
  ut_ad(size <= UNIV_PAGE_SIZE);

  return (static_cast<byte *>(
      buf_buddy_alloc_low(buf_pool, buf_buddy_get_slot(size))));
}

/** Deallocate a block.
@param[in,out]	buf_pool	buffer pool in which the block resides
@param[in]	buf		block to be freed, must not be pointed to
                                by the buffer pool
@param[in]	size		block size, up to UNIV_PAGE_SIZE */
UNIV_INLINE
void buf_buddy_free(buf_pool_t *buf_pool, void *buf, ulint size) {
  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), false);
}

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