branches/zip: Add buf_pool->zip_hash for keeping track on pages allocated

to the buddy system for allocating compressed pages and their descriptors.

buf_buddy_free_block(): New function: Deallocate the buffer frame.

buf_buddy_free(), buf_buddy_free_low(): Return void instead of a pointer
to a freed buffer frame.

buf/buf0buddy.c

@@ -13,6 +13,7 @@ Created December 2006 by Marko Makela
 #endif
 #undef THIS_MODULE
 #include "buf0buf.h"
+#include "buf0lru.h"
 #include "buf0flu.h"
 #include "page0page.h"
 
@@ -54,6 +55,34 @@ buf_buddy_alloc_low(
 	return(bpage);
 }
 
+/**************************************************************************
+Deallocate a buffer frame of UNIV_PAGE_SIZE. */
+static
+void
+buf_buddy_free_block(
+/*=================*/
+	void*	buf)	/* in: buffer frame to deallocate */
+{
+	ulint		fold	= (ulint) buf / UNIV_PAGE_SIZE;
+	buf_page_t*	bpage;
+	buf_block_t*	block;
+
+#ifdef UNIV_SYNC_DEBUG
+	ut_a(mutex_own(&buf_pool->mutex));
+#endif /* UNIV_SYNC_DEBUG */
+	ut_a(buf == ut_align_down(buf, UNIV_PAGE_SIZE));
+
+	HASH_SEARCH(hash, buf_pool->zip_hash, fold, bpage,
+		    ((buf_block_t*) bpage)->frame == buf);
+	ut_a(bpage);
+	ut_a(buf_page_get_state(bpage) == BUF_BLOCK_MEMORY);
+
+	block = (buf_block_t*) bpage;
+	mutex_enter(&block->mutex);
+	buf_LRU_block_free_non_file_page(block);
+	mutex_exit(&block->mutex);
+}
+
 /**************************************************************************
 Try to relocate a block. */
 static
@@ -188,15 +217,11 @@ buf_buddy_relocate(
 }
 
 /**************************************************************************
-Release a block to buf_pool->zip_free[]. */
+Deallocate a block. */
 
-void*
+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[] */
 {
@@ -246,7 +271,8 @@ buddy_free:
 			}
 
 			/* The whole block is free. */
-			return(buf);
+			buf_buddy_free_block(buf);
+			return;
 		}
 
 		ut_a(bpage != buf);
@@ -289,6 +315,4 @@ buddy_free:
 	bpage = buf;
 	bpage->state = BUF_BLOCK_ZIP_FREE;
 	UT_LIST_ADD_FIRST(list, buf_pool->zip_free[i], bpage);
-
-	return(NULL);
 }

buf/buf0buf.c

@@ -845,6 +845,7 @@ buf_pool_init(void)
 	srv_buf_pool_curr_size = buf_pool->curr_size * UNIV_PAGE_SIZE;
 
 	buf_pool->page_hash = hash_create(2 * buf_pool->curr_size);
+	buf_pool->zip_hash = hash_create(2 * buf_pool->curr_size);
 
 	buf_pool->n_pend_reads = 0;
 
@@ -1067,6 +1068,7 @@ buf_pool_page_hash_rebuild(void)
 	/* Free, create, and populate the hash table. */
 	hash_table_free(buf_pool->page_hash);
 	buf_pool->page_hash = page_hash = hash_create(2 * buf_pool->curr_size);
+	/* TODO: buf_pool->zip_hash */
 
 	chunk = buf_pool->chunks;
 	n_chunks = buf_pool->n_chunks;

include/buf0buddy.h

@@ -53,15 +53,11 @@ buf_buddy_alloc(
 	__attribute__((malloc));
 
 /**************************************************************************
-Release a block to buf_pool->zip_free[]. */
+Release a block. */
 UNIV_INLINE
-void*
+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));

include/buf0buddy.ic

@@ -28,15 +28,11 @@ buf_buddy_alloc_low(
 	__attribute__((malloc));
 
 /**************************************************************************
-Release a block to buf_pool->zip_free[]. */
+Deallocate a block. */
 
-void*
+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));
@@ -98,15 +94,11 @@ buf_buddy_alloc(
 }
 
 /**************************************************************************
-Release a block to buf_pool->zip_free[]. */
+Deallocate a block. */
 UNIV_INLINE
-void*
+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 */
 {
@@ -114,7 +106,7 @@ buf_buddy_free(
 	ut_a(mutex_own(&buf_pool->mutex));
 #endif /* UNIV_SYNC_DEBUG */
 
-	return(buf_buddy_free_low(buf, buf_buddy_get_slot(size)));
+	buf_buddy_free_low(buf, buf_buddy_get_slot(size));
 }
 
 #ifdef UNIV_MATERIALIZE

include/buf0buf.h

@@ -915,8 +915,9 @@ struct buf_page_struct{
 					is currently bufferfixed */
 
 	page_zip_des_t	zip;		/* compressed page */
-	buf_page_t*	hash;		/* node used in chaining to the page
-					hash table */
+	buf_page_t*	hash;		/* node used in chaining to
+					buf_pool->page_hash or
+					buf_pool->zip_hash */
 
 	/* 2. Page flushing fields; protected by buf_pool->mutex */
 
@@ -1095,8 +1096,14 @@ struct buf_pool_struct{
 	ulint		n_chunks;	/* number of buffer pool chunks */
 	buf_chunk_t*	chunks;		/* buffer pool chunks */
 	ulint		curr_size;	/* current pool size in pages */
-	hash_table_t*	page_hash;	/* hash table of the file pages */
-
+	hash_table_t*	page_hash;	/* hash table of buf_page_t or
+					buf_block_t file pages,
+					buf_page_in_file() == TRUE,
+					indexed by (space_id, offset) */
+	hash_table_t*	zip_hash;	/* hash table of buf_block_t blocks
+					whose frames are allocated to the
+					zip buddy system,
+					indexed by block->frame */
 	ulint		n_pend_reads;	/* number of pending read operations */
 
 	time_t		last_printout_time; /* when buf_print was last time