branches/zip: Improve the clearing of deleted records. Try to support

operations on BLOB columns.  There are some bugs in the code, because
test-insert and a few other tests fail.

page_mem_free(): Add parameter index.  Decrement PAGE_N_RECS here.
Move some operations to page_zip_dir_delete().

page_zip_clear_rec(): Make this a static function.

page_zip_dir_delete(): Add parameters index and offsets.
Decrement PAGE_N_RECS and clear info_bits and n_owned.

page_zip_get_n_prev_extern(): Correct the synopsis and the algorithm.
Add parameter page_zip.  Search the records in heap_no order instead
of collation order.

page_zip_compress(), page_zip_decompress(): Only copy BLOB pointers
and increment n_blobs for records that have not been deleted.

page_zip_clear_rec(): Clear trx_id and roll_ptr on the compressed page.

page_zip_dir_delete(): Decrement PAGE_N_RECS.  Shift the array of
BLOB pointers.  Call page_zip_clear_rec().

page_zip_dir_add_slot(): Shift the array of BLOB pointers to make
space of roll_ptr and trx_id.

page_cur_delete_rec(): Do not decrement PAGE_N_RECS or call
page_zip_clear_rec(), as page_mem_free() already does it.

include/page0page.h

@@ -604,6 +604,7 @@ page_mem_free(
 	page_zip_des_t*	page_zip,/* in/out: compressed page with at least
 				6 bytes available, or NULL */
 	rec_t*		rec,	/* in: pointer to the (origin of) record */
+	dict_index_t*	index,	/* in: index of rec */
 	const ulint*	offsets);/* in: array returned by rec_get_offsets() */
 /**************************************************************
 The index page creation function. */

include/page0page.ic

@@ -909,33 +909,29 @@ page_mem_free(
 	page_zip_des_t*	page_zip,/* in/out: compressed page with at least
 				6 bytes available, or NULL */
 	rec_t*		rec,	/* in: pointer to the (origin of) record */
+	dict_index_t*	index,	/* in: index of rec */
 	const ulint*	offsets)/* in: array returned by rec_get_offsets() */
 {
 	rec_t*		free;
 	ulint		garbage;
 
-	ut_ad(rec_offs_validate(rec, NULL, offsets));
-	ut_ad(!rec_offs_comp(offsets) == !page_rec_is_comp(rec));
+	ut_ad(rec_offs_validate(rec, index, offsets));
 	free = page_header_get_ptr(page, PAGE_FREE);
 
 	page_rec_set_next(rec, free);
 	page_header_set_ptr(page, page_zip, PAGE_FREE, rec);
 
-	if (UNIV_LIKELY_NULL(page_zip)) {
-		ut_ad(rec_offs_comp(offsets));
-
-		/* The compression algorithm expects info_bits and n_owned
-		to be 0 for deleted records. */
-		rec[-REC_N_NEW_EXTRA_BYTES] = 0; /* info_bits and n_owned */
-
-		/* Update the dense page directory. */
-		page_zip_dir_delete(page_zip, rec, free);
-	}
-
 	garbage = page_header_get_field(page, PAGE_GARBAGE);
 
 	page_header_set_field(page, page_zip, PAGE_GARBAGE,
 				garbage + rec_offs_size(offsets));
+
+	if (UNIV_LIKELY_NULL(page_zip)) {
+		page_zip_dir_delete(page_zip, rec, index, offsets, free);
+	} else {
+		page_header_set_field(page, page_zip, PAGE_N_RECS,
+				(ulint)(page_get_n_recs(page) - 1));
+	}
 }
 
 #ifdef UNIV_MATERIALIZE

include/page0types.h

@@ -53,19 +53,6 @@ page_zip_write(
 	ulint		length)	/* in: length of the data */
 	__attribute__((nonnull));
 
-/**************************************************************************
-Clear a record on the uncompressed and compressed page, if possible. */
-
-void
-page_zip_clear_rec(
-/*===============*/
-	page_zip_des_t*	page_zip,/* in/out: compressed page */
-	byte*		rec,	/* in: record to clear */
-	dict_index_t*	index,	/* in: index of rec */
-	const ulint*	offsets,/* in: rec_get_offsets(rec, index) */
-	mtr_t*		mtr)	/* in: mini-transaction */
-	__attribute__((nonnull));
-
 /**************************************************************************
 Write data to the uncompressed header portion of a page.  The data must
 already have been written to the uncompressed page. */
@@ -110,9 +97,11 @@ void
 page_zip_dir_delete(
 /*================*/
 	page_zip_des_t*	page_zip,/* in/out: compressed page */
-	const byte*	rec,	/* in: deleted record */
+	byte*		rec,	/* in: deleted record */
+	dict_index_t*	index,	/* in: index of rec */
+	const ulint*	offsets,/* in: rec_get_offsets(rec) */
 	const byte*	free)	/* in: previous start of the free list */
-	__attribute__((nonnull(1,2)));
+	__attribute__((nonnull(1,2,3,4)));
 
 /**************************************************************************
 Add a slot to the dense page directory. */

include/page0zip.h

@@ -161,19 +161,6 @@ page_zip_write_trx_id_and_roll_ptr(
 	dulint		roll_ptr)/* in: roll_ptr */
 	__attribute__((nonnull));
 
-/**************************************************************************
-Clear a record on the uncompressed and compressed page, if possible. */
-
-void
-page_zip_clear_rec(
-/*===============*/
-	page_zip_des_t*	page_zip,/* in/out: compressed page */
-	byte*		rec,	/* in/out: record to clear */
-	dict_index_t*	index,	/* in: index of rec */
-	const ulint*	offsets,/* in: rec_get_offsets(rec, index) */
-	mtr_t*		mtr)	/* in: mini-transaction */
-	__attribute__((nonnull));
-
 /**************************************************************************
 Populate the dense page directory on the compressed page
 from the sparse directory on the uncompressed row_format=compact page. */
@@ -216,9 +203,11 @@ void
 page_zip_dir_delete(
 /*================*/
 	page_zip_des_t*	page_zip,/* in/out: compressed page */
-	const byte*	rec,	/* in: deleted record */
+	byte*		rec,	/* in: deleted record */
+	dict_index_t*	index,	/* in: index of rec */
+	const ulint*	offsets,/* in: rec_get_offsets(rec) */
 	const byte*	free)	/* in: previous start of the free list */
-	__attribute__((nonnull(1,2)));
+	__attribute__((nonnull(1,2,3,4)));
 
 /**************************************************************************
 Add a slot to the dense page directory. */

page/page0cur.c

@@ -1535,18 +1535,7 @@ page_cur_delete_rec(
 	page_dir_slot_set_n_owned(cur_dir_slot, page_zip, cur_n_owned - 1);
 
 	/* 6. Free the memory occupied by the record */
-	page_mem_free(page, page_zip, current_rec, offsets);
-	page_header_set_field(page, page_zip, PAGE_N_RECS,
-				(ulint)(page_get_n_recs(page) - 1));
-	if (UNIV_LIKELY_NULL(page_zip)) {
-		/* Clear the data bytes of the deleted record in order
-		to improve the compression ratio of the page.  The fixed extra
-		bytes of the record, which will be omitted from the
-		stream compression algorithm, cannot be cleared, because
-		page_mem_alloc() needs them in order to determine the size
-		of the deleted record. */
-		page_zip_clear_rec(page_zip, rec, index, offsets, mtr);
-	}
+	page_mem_free(page, page_zip, current_rec, index, offsets);
 
 	/* 7. Now we have decremented the number of owned records of the slot.
 	If the number drops below PAGE_DIR_SLOT_MIN_N_OWNED, we balance the