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compressed pages from the buffer pool. Makefile.am: Add buf0buddy.h, buf0buddy.ic. buf/Makefile.am: Add buf0buddy.c. Introduce the constants BUF_BUDDY_LOW and BUF_BUDDY_SIZES. buf_pool_t: Add zip_mutex and the lists zip_clean and zip_free[]. buf_page_get_mutex(): Return &buf_pool->zip_mutex instead of NULL. buf_buddy_get_offset(), buf_buddy_get(), buf_buddy_get_slot(), buf_buddy_alloc_free(), buf_buddy_alloc_free_low(): New functions.
85 lines
2.1 KiB
Text
85 lines
2.1 KiB
Text
/******************************************************
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Binary buddy allocator for compressed pages
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(c) 2006 Innobase Oy
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Created December 2006 by Marko Makela
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*******************************************************/
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#ifdef UNIV_MATERIALIZE
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# undef UNIV_INLINE
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# define UNIV_INLINE
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#endif
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#include "buf0buddy.h"
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#include "ut0ut.h"
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/**************************************************************************
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Try to allocate a block from buf_pool->zip_free[]. */
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void*
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buf_buddy_alloc_free_low(
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/*=====================*/
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/* out: allocated block, or NULL
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if buf_pool->zip_free[] was empty */
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ulint i) /* in: index of buf_pool->zip_free[] */
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__attribute__((malloc));
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/**************************************************************************
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Get the offset of the buddy of a compressed page frame. */
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UNIV_INLINE
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lint
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buf_buddy_get_offset(
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/*=================*/
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/* out: offset of the buddy relative to page */
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const void* page, /* in: compressed page */
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ulint size) /* in: page size in bytes */
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{
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ut_ad(ut_is_2pow(size));
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ut_ad(size >= BUF_BUDDY_LOW);
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ut_ad(size < BUF_BUDDY_LOW << BUF_BUDDY_SIZES);
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if (((ulint) page) & size) {
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return(-(lint) size);
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} else {
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return((lint) size);
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}
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}
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/**************************************************************************
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Get the index of buf_pool->zip_free[] for a given block size. */
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UNIV_INLINE
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ulint
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buf_buddy_get_slot(
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/*===============*/
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/* out: index of buf_pool->zip_free[] */
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ulint size) /* in: block size */
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{
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ulint i;
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ulint s;
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for (i = 0, s = BUF_BUDDY_LOW; s < size; i++, s <<= 1);
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ut_ad(i < BUF_BUDDY_SIZES);
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return(i);
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}
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/**************************************************************************
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Try to allocate a block from buf_pool->zip_free[]. */
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UNIV_INLINE
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void*
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buf_buddy_alloc_free(
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/*=================*/
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ulint size) /* in: block size, up to UNIV_PAGE_SIZE / 2 */
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{
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#ifdef UNIV_SYNC_DEBUG
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ut_a(mutex_own(&buf_pool->mutex));
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#endif /* UNIV_SYNC_DEBUG */
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return(buf_buddy_alloc_free_low(buf_buddy_get_slot(size)));
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}
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#ifdef UNIV_MATERIALIZE
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# undef UNIV_INLINE
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# define UNIV_INLINE UNIV_INLINE_ORIGINAL
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#endif
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