branches/zip: Implement crash recovery of writing to the page header.

page_zip_parse_write_header(): New function for applying the redo log of
MLOG_ZIP_WRITE_HEADER.

page_zip_parse_write_node_ptr(): Mark the log corrupted if !page_zip.

include/page0zip.h

@@ -232,6 +232,18 @@ page_zip_dir_add_slot(
 					zero for others */
 	__attribute__((nonnull));
 
+/***************************************************************
+Parses a log record of writing to the header of a page. */
+
+byte*
+page_zip_parse_write_header(
+/*========================*/
+				/* out: end of log record or NULL */
+	byte*		ptr,	/* in: redo log buffer */
+	byte*		end_ptr,/* in: redo log buffer end */
+	page_t*		page,	/* in/out: uncompressed page */
+	page_zip_des_t*	page_zip);/* in/out: compressed page */
+
 /**************************************************************************
 Write data to the uncompressed header portion of a page.  The data must
 already have been written to the uncompressed page.

log/log0recv.c

@@ -898,7 +898,8 @@ recv_parse_or_apply_log_rec_body(
 				ptr, end_ptr, page, page_zip);
 		break;
 	case MLOG_ZIP_WRITE_HEADER:
-		ut_error; /* TODO */
+		ptr = page_zip_parse_write_header(
+				ptr, end_ptr, page, page_zip);
 		break;
 	case MLOG_ZIP_COMPRESS:
 		if (NULL != (ptr = mlog_parse_index(

page/page0zip.c

@@ -2248,7 +2248,8 @@ page_zip_parse_write_node_ptr(
 
 	if (UNIV_UNLIKELY(offset < PAGE_ZIP_START)
 			|| UNIV_UNLIKELY(offset >= UNIV_PAGE_SIZE)
-			|| UNIV_UNLIKELY(z_offset >= UNIV_PAGE_SIZE)) {
+			|| UNIV_UNLIKELY(z_offset >= UNIV_PAGE_SIZE)
+			|| UNIV_UNLIKELY(!page_zip)) {
 corrupt:
 		recv_sys->found_corrupt_log = TRUE;
 
@@ -2712,6 +2713,60 @@ page_zip_dir_add_slot(
 	memmove(stored - PAGE_ZIP_DIR_SLOT_SIZE, stored, dir - stored);
 }
 
+/***************************************************************
+Parses a log record of writing to the header of a page. */
+
+byte*
+page_zip_parse_write_header(
+/*========================*/
+				/* out: end of log record or NULL */
+	byte*		ptr,	/* in: redo log buffer */
+	byte*		end_ptr,/* in: redo log buffer end */
+	page_t*		page,	/* in/out: uncompressed page */
+	page_zip_des_t*	page_zip)/* in/out: compressed page */
+{
+	ulint	offset;
+	ulint	len;
+
+	ut_ad(!page == !page_zip);
+
+	if (UNIV_UNLIKELY(end_ptr < ptr + (2 + 1))) {
+
+		return(NULL);
+	}
+
+	offset = mach_read_from_2(ptr);
+	ptr += 2;
+	len = (ulint) *ptr++;
+
+	if (UNIV_UNLIKELY(!len) || UNIV_UNLIKELY(offset + len >= PAGE_DATA)
+			|| UNIV_UNLIKELY(!page_zip)) {
+		recv_sys->found_corrupt_log = TRUE;
+
+		return(NULL);
+	}
+
+	if (UNIV_UNLIKELY(end_ptr < ptr + len)) {
+
+		return(NULL);
+	}
+
+	if (page) {
+#if defined UNIV_DEBUG || defined UNIV_ZIP_DEBUG
+		ut_a(page_zip_validate(page_zip, page));
+#endif /* UNIV_DEBUG || UNIV_ZIP_DEBUG */
+
+		memcpy(page + offset, ptr, len);
+		memcpy(page_zip->data + offset, ptr, len);
+
+#if defined UNIV_DEBUG || defined UNIV_ZIP_DEBUG
+		ut_a(page_zip_validate(page_zip, page));
+#endif /* UNIV_DEBUG || UNIV_ZIP_DEBUG */
+	}
+
+	return(ptr + len);
+}
+
 /**************************************************************************
 Write a log record of writing to the uncompressed header portion of a page. */