branches/zip: Fix some bugs in incremental compression.

btr_create(): page_zip_compress() returns FALSE on failure.

page_zip_write_header(): Write to page_zip->data[] instead of page_zip[].

buf_flush_init_for_writing(): Add parameter page_zip and set the fields
also in the header of the compressed page.

btr_cur_search_to_nth_level(): Add ut_ad() on page_zip_validate().

btr/btr0btr.c

@@ -763,7 +763,7 @@ btr_create(
 
 	page_zip = buf_block_get_page_zip(buf_block_align(page));
 	if (UNIV_LIKELY_NULL(page_zip)) {
-		if (UNIV_UNLIKELY(page_zip_compress(
+		if (UNIV_UNLIKELY(!page_zip_compress(
 				page_zip, page, index, mtr))) {
 			/* An empty page should always be compressible */
 			ut_error;

btr/btr0cur.c

@@ -450,6 +450,7 @@ btr_cur_search_to_nth_level(
 	/* Loop and search until we arrive at the desired level */
 
 	for (;;) {
+		buf_block_t*	block;
 retry_page_get:
 		page = buf_page_get_gen(space, page_no, rw_latch, guess,
 					buf_mode,
@@ -482,7 +483,12 @@ btr_cur_search_to_nth_level(
 			goto retry_page_get;
 		}
 
-		buf_block_align(page)->check_index_page_at_flush = TRUE;
+		block = buf_block_align(page);
+
+		ut_ad(!buf_block_get_page_zip(block) || page_zip_validate(
+				buf_block_get_page_zip(block), page));
+
+		block->check_index_page_at_flush = TRUE;
 
 #ifdef UNIV_SYNC_DEBUG
 		if (rw_latch != RW_NO_LATCH) {

buf/buf0flu.c

@@ -447,11 +447,14 @@ Initializes a page for writing to the tablespace. */
 void
 buf_flush_init_for_writing(
 /*=======================*/
-	byte*	page,		/* in: page */
+	byte*	page,		/* in/out: page */
+	void*	page_zip_,	/* in/out: compressed page, or NULL */
 	dulint	newest_lsn,	/* in: newest modification lsn to the page */
 	ulint	space,		/* in: space id */
 	ulint	page_no)	/* in: page number */
 {
+	page_zip_des_t*	page_zip = page_zip_;
+
 	/* Write the newest modification lsn to the page header and trailer */
 	mach_write_to_8(page + FIL_PAGE_LSN, newest_lsn);
 
@@ -468,6 +471,14 @@ buf_flush_init_for_writing(
 					srv_use_checksums ?
 		buf_calc_page_new_checksum(page) : BUF_NO_CHECKSUM_MAGIC);
 
+	if (UNIV_LIKELY_NULL(page_zip)) {
+		/* Copy FIL_PAGE_SPACE_OR_CHKSUM and FIL_PAGE_OFFSET */
+		memcpy(page_zip->data, page, FIL_PAGE_PREV);
+		/* Copy FIL_PAGE_ARCH_LOG_NO_OR_SPACE_ID */
+		memcpy(page_zip->data + FIL_PAGE_ARCH_LOG_NO_OR_SPACE_ID,
+			page + FIL_PAGE_ARCH_LOG_NO_OR_SPACE_ID, 4);
+	}
+
 	/* We overwrite the first 4 bytes of the end lsn field to store
 	the old formula checksum. Since it depends also on the field
 	FIL_PAGE_SPACE_OR_CHKSUM, it has to be calculated after storing the
@@ -510,8 +521,10 @@ buf_flush_write_block_low(
 	/* Force the log to the disk before writing the modified block */
 	log_write_up_to(block->newest_modification, LOG_WAIT_ALL_GROUPS, TRUE);
 #endif
-	buf_flush_init_for_writing(block->frame, block->newest_modification,
-						block->space, block->offset);
+	buf_flush_init_for_writing(block->frame,
+			buf_block_get_page_zip(block),
+			block->newest_modification,
+			block->space, block->offset);
 	if (!srv_use_doublewrite_buf || !trx_doublewrite) {
 		fil_io(OS_FILE_WRITE | OS_AIO_SIMULATED_WAKE_LATER,
 			FALSE, block->space, block->offset, 0, UNIV_PAGE_SIZE,

fil/fil0fil.c

@@ -2432,7 +2432,8 @@ fil_create_new_single_table_tablespace(
 
 	fsp_header_write_space_id(page, *space_id);
 
-	buf_flush_init_for_writing(page, ut_dulint_zero, *space_id, 0);
+	buf_flush_init_for_writing(page, NULL/* TODO: page_zip */,
+				ut_dulint_zero, *space_id, 0);
 
 	ret = os_file_write(path, file, page, 0, 0, UNIV_PAGE_SIZE);
 
@@ -2594,8 +2595,9 @@ fil_reset_too_high_lsns(
 					+ FIL_PAGE_ARCH_LOG_NO_OR_SPACE_ID);
 			page_no = mach_read_from_4(page + FIL_PAGE_OFFSET);
 
-			buf_flush_init_for_writing(page, current_lsn, space_id,
-				page_no);
+			buf_flush_init_for_writing(page,
+					NULL/* TODO: page_zip */,
+					current_lsn, space_id, page_no);
 			success = os_file_write(filepath, file, page,
 				(ulint)(offset & 0xFFFFFFFFUL),
 				(ulint)(offset >> 32), UNIV_PAGE_SIZE);

include/buf0flu.h

@@ -34,7 +34,8 @@ Initializes a page for writing to the tablespace. */
 void
 buf_flush_init_for_writing(
 /*=======================*/
-	byte*	page,		/* in: page */
+	byte*	page,		/* in/out: page */
+	void*	page_zip,	/* in/out: compressed page, or NULL */
 	dulint	newest_lsn,	/* in: newest modification lsn to the page */
 	ulint	space,		/* in: space id */
 	ulint	page_no);	/* in: page number */

include/page0zip.ic

@@ -272,7 +272,7 @@ page_zip_write_header(
 
 	ut_ad(pos < PAGE_DATA);
 
-	memcpy(page_zip + pos, str, length);
+	memcpy(page_zip->data + pos, str, length);
 
 	/* The following would fail in page_cur_insert_rec_low(). */
 	/* ut_ad(page_zip_validate(page_zip, str - pos)); */

log/log0recv.c

@@ -1612,6 +1612,7 @@ recv_addr->space, recv_addr->page_no);
 			fil0fil.c routines */
 
 			buf_flush_init_for_writing(page,
+				NULL,/* TODO: page_zip */
 				mach_read_from_8(page + FIL_PAGE_LSN),
 				recv_addr->space, recv_addr->page_no);