branches/zip: Add buf_buddy_free() and buf_buddy_free_low().

buf/buf0buddy.c

@@ -51,3 +51,57 @@ buf_buddy_alloc_low(
 
 	return(bpage);
 }
+
+/**************************************************************************
+Release a block to buf_pool->zip_free[]. */
+
+void*
+buf_buddy_free_low(
+/*===============*/
+			/* out: pointer to the beginning of a block of
+			size BUF_BUDDY_HIGH that should be freed to
+			the underlying allocator, or NULL if released
+			to buf_pool->zip_free[] */
+	void*	buf,	/* in: block to free */
+	ulint	i)	/* in: index of buf_pool->zip_free[] */
+{
+	buf_page_t*	bpage;
+	buf_page_t*	buddy;
+#ifdef UNIV_SYNC_DEBUG
+	ut_a(mutex_own(&buf_pool->mutex));
+#endif /* UNIV_SYNC_DEBUG */
+recombine:
+	ut_ad(i < BUF_BUDDY_SIZES);
+	ut_ad(buf == ut_align_down(buf, BUF_BUDDY_LOW << i));
+
+	/* Try to combine adjacent blocks. */
+
+	buddy = buf_buddy_get(buf, BUF_BUDDY_LOW << i);
+
+	for (bpage = UT_LIST_GET_FIRST(buf_pool->zip_free[i]);
+	     bpage; bpage = UT_LIST_GET_NEXT(list, bpage)) {
+
+		if (bpage == buddy) {
+			/* The buddy is free: recombine */
+			UT_LIST_REMOVE(list, buf_pool->zip_free[i], bpage);
+			buf = ut_align_down(buf, BUF_BUDDY_LOW << i);
+
+			if (++i < BUF_BUDDY_SIZES) {
+
+				goto recombine;
+			}
+
+			/* The whole block is free. */
+			return(buf);
+		}
+
+		ut_a(bpage != buf);
+	}
+
+	/* Free the block to the buddy list. */
+	bpage = buf;
+	bpage->state = BUF_BLOCK_ZIP_FREE;
+	UT_LIST_ADD_FIRST(list, buf_pool->zip_free[i], bpage);
+
+	return(NULL);
+}

include/buf0buddy.h

@@ -52,6 +52,20 @@ buf_buddy_alloc(
 			FALSE=try to allocate exact size */
 	__attribute__((malloc));
 
+/**************************************************************************
+Release a block to buf_pool->zip_free[]. */
+UNIV_INLINE
+void*
+buf_buddy_free(
+/*===========*/
+			/* out: pointer to the beginning of a block of
+			size BUF_BUDDY_HIGH that should be freed to
+			the underlying allocator, or NULL if released
+			to buf_pool->zip_free[] */
+	void*	buf,	/* in: block to free */
+	ulint	size)	/* in: block size, up to UNIV_PAGE_SIZE / 2 */
+	__attribute__((nonnull));
+
 #ifndef UNIV_NONINL
 # include "buf0buddy.ic"
 #endif

include/buf0buddy.ic

@@ -27,6 +27,20 @@ buf_buddy_alloc_low(
 			FALSE=try to allocate exact size */
 	__attribute__((malloc));
 
+/**************************************************************************
+Release a block to buf_pool->zip_free[]. */
+
+void*
+buf_buddy_free_low(
+/*===============*/
+			/* out: pointer to the beginning of a block of
+			size BUF_BUDDY_HIGH that should be freed to
+			the underlying allocator, or NULL if released
+			to buf_pool->zip_free[] */
+	void*	buf,	/* in: block to free */
+	ulint	i)	/* in: index of buf_pool->zip_free[] */
+	__attribute__((nonnull));
+
 /**************************************************************************
 Get the offset of the buddy of a compressed page frame. */
 UNIV_INLINE
@@ -83,6 +97,26 @@ buf_buddy_alloc(
 	return(buf_buddy_alloc_low(buf_buddy_get_slot(size), split));
 }
 
+/**************************************************************************
+Release a block to buf_pool->zip_free[]. */
+UNIV_INLINE
+void*
+buf_buddy_free(
+/*===========*/
+			/* out: pointer to the beginning of a block of
+			size BUF_BUDDY_HIGH that should be freed to
+			the underlying allocator, or NULL if released
+			to buf_pool->zip_free[] */
+	void*	buf,	/* in: block to free */
+	ulint	size)	/* in: block size, up to UNIV_PAGE_SIZE / 2 */
+{
+#ifdef UNIV_SYNC_DEBUG
+	ut_a(mutex_own(&buf_pool->mutex));
+#endif /* UNIV_SYNC_DEBUG */
+
+	return(buf_buddy_free_low(buf, buf_buddy_get_slot(size)));
+}
+
 #ifdef UNIV_MATERIALIZE
 # undef UNIV_INLINE
 # define UNIV_INLINE	UNIV_INLINE_ORIGINAL