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/******************************************************
Binary buddy allocator for compressed pages
(c) 2006 Innobase Oy
Created December 2006 by Marko Makela
*******************************************************/
#ifdef UNIV_MATERIALIZE
# undef UNIV_INLINE
# define UNIV_INLINE
#endif
#include "buf0buddy.h"
#include "ut0ut.h"
/**************************************************************************
Try to allocate a block from buf_pool->zip_free[]. */
void*
buf_buddy_alloc_low(
/*================*/
/* out: allocated block, or NULL
if buf_pool->zip_free[] was empty */
ulint i, /* in: index of buf_pool->zip_free[] */
ibool split) /* in: TRUE=attempt splitting,
FALSE=try to allocate exact size */
__attribute__((malloc));
/**************************************************************************
Get the offset of the buddy of a compressed page frame. */
UNIV_INLINE
lint
buf_buddy_get_offset(
/*=================*/
/* out: offset of the buddy relative to page */
const void* page, /* in: compressed page */
ulint size) /* in: page size in bytes */
{
ut_ad(ut_is_2pow(size));
ut_ad(size >= BUF_BUDDY_LOW);
ut_ad(size < BUF_BUDDY_HIGH);
if (((ulint) page) & size) {
return(-(lint) size);
} else {
return((lint) size);
}
}
/**************************************************************************
Get the index of buf_pool->zip_free[] for a given block size. */
UNIV_INLINE
ulint
buf_buddy_get_slot(
/*===============*/
/* out: index of buf_pool->zip_free[] */
ulint size) /* in: block size */
{
ulint i;
ulint s;
for (i = 0, s = BUF_BUDDY_LOW; s < size; i++, s <<= 1);
ut_ad(i < BUF_BUDDY_SIZES);
return(i);
}
/**************************************************************************
Try to allocate a block from buf_pool->zip_free[]. */
UNIV_INLINE
void*
buf_buddy_alloc(
/*============*/
ulint size, /* in: block size, up to UNIV_PAGE_SIZE / 2 */
ibool split) /* in: TRUE=attempt splitting,
FALSE=try to allocate exact size */
{
#ifdef UNIV_SYNC_DEBUG
ut_a(mutex_own(&buf_pool->mutex));
#endif /* UNIV_SYNC_DEBUG */
return(buf_buddy_alloc_low(buf_buddy_get_slot(size), split));
}
#ifdef UNIV_MATERIALIZE
# undef UNIV_INLINE
# define UNIV_INLINE UNIV_INLINE_ORIGINAL
#endif