branches/zip: Initial steps towards disk-based storage of compressed pages.

dict_mem_table_create(): Account for DICT_TF_COMPRESSED in a debug assertion.

btr_store_big_rec_extern_fields(), btr_free_externally_stored_field(),
btr_copy_externally_stored_field(): Implement the disk format for
compressed BLOB pages.

btr_copy_externally_stored_field(): Improve error reporting and handling
when decompressing BLOB pages.

buf_flush_init_for_writing(), buf_page_is_corrupted(), buf_page_print():
Account for compressed BLOB pages (FIL_PAGE_TYPE_ZBLOB).

buf_calc_zblob_page_checksum(): New function.

btr/btr0cur.c

@@ -3575,9 +3575,6 @@ btr_store_big_rec_extern_fields(
 				return(DB_OUT_OF_FILE_SPACE);
 			}
 
-			mlog_write_ulint(page + FIL_PAGE_TYPE,
-					FIL_PAGE_TYPE_BLOB, MLOG_2BYTES, &mtr);
-
 			page_no = buf_frame_get_page_no(page);
 
 			if (prev_page_no != FIL_NULL) {
@@ -3592,7 +3589,7 @@ btr_store_big_rec_extern_fields(
 #endif /* UNIV_SYNC_DEBUG */
 
 				if (UNIV_LIKELY_NULL(page_zip)) {
-					next_ptr = prev_page;
+					next_ptr = prev_page + FIL_PAGE_NEXT;
 				} else {
 					next_ptr = prev_page + FIL_PAGE_DATA
 						+ BTR_BLOB_HDR_NEXT_PAGE_NO;
@@ -3605,8 +3602,13 @@ btr_store_big_rec_extern_fields(
 			if (UNIV_LIKELY_NULL(page_zip)) {
 				int	err;
 
-				c_stream.next_out = page + 4;
-				c_stream.avail_out = UNIV_PAGE_SIZE - 4;
+				mach_write_to_4(page + FIL_PAGE_TYPE,
+						FIL_PAGE_TYPE_ZBLOB);
+
+				c_stream.next_out = page
+					+ FIL_PAGE_FILE_FLUSH_LSN;
+				c_stream.avail_out = page_zip->size
+					- FIL_PAGE_FILE_FLUSH_LSN;
 
 				err = deflate(&c_stream, Z_FINISH);
 				ut_a(err == Z_OK || err == Z_STREAM_END);
@@ -3614,12 +3616,14 @@ btr_store_big_rec_extern_fields(
 					|| c_stream.avail_out == 0);
 
 				/* Write the "next BLOB page" pointer */
-				mach_write_to_4(page, FIL_NULL);
+				mlog_write_ulint(page + FIL_PAGE_NEXT,
+						FIL_NULL, MLOG_4BYTES, &mtr);
 				/* Zero out the unused part of the page. */
-				memset(page + UNIV_PAGE_SIZE
+				memset(page + page_zip->size
 					- c_stream.avail_out,
 					0, c_stream.avail_out);
-				mlog_log_string(page, UNIV_PAGE_SIZE, &mtr);
+				mlog_log_string(page + FIL_PAGE_TYPE,
+					page_zip->size - FIL_PAGE_TYPE, &mtr);
 
 				if (err == Z_OK && prev_page_no != FIL_NULL) {
 
@@ -3663,7 +3667,7 @@ btr_store_big_rec_extern_fields(
 
 					mlog_write_ulint(field_ref
 							+ BTR_EXTERN_OFFSET,
-							FIL_PAGE_DATA,
+							FIL_PAGE_NEXT,
 							MLOG_4BYTES, &mtr);
 				}
 
@@ -3680,6 +3684,10 @@ btr_store_big_rec_extern_fields(
 					break;
 				}
 			} else {
+				mlog_write_ulint(page + FIL_PAGE_TYPE,
+						FIL_PAGE_TYPE_BLOB,
+						MLOG_2BYTES, &mtr);
+
 				if (extern_len > (UNIV_PAGE_SIZE
 						- FIL_PAGE_DATA
 						- BTR_BLOB_HDR_SIZE
@@ -3851,7 +3859,7 @@ btr_free_externally_stored_field(
 		if (dict_table_is_zip(index->table)) {
 			/* Note that page_zip will be NULL
 			in row_purge_upd_exist_or_extern(). */
-			next_page_no = mach_read_from_4(page);
+			next_page_no = mach_read_from_4(page + FIL_PAGE_NEXT);
 
 			btr_page_free_low(index->tree, page,
 						space_id, page_no, 0, &mtr);
@@ -4015,7 +4023,8 @@ btr_copy_externally_stored_field(
 	byte*		data,	/* in: 'internally' stored part of the
 				field containing also the reference to
 				the external part */
-	ibool		zip,	/* in: TRUE=compressed BLOB */
+	ulint		zip_size,/* in: nonzero=compressed BLOB page size,
+				zero for uncompressed BLOBs */
 	ulint		local_len,/* in: length of data */
 	mem_heap_t*	heap)	/* in: mem heap */
 {
@@ -4055,7 +4064,7 @@ btr_copy_externally_stored_field(
 		return(buf);
 	}
 
-	if (UNIV_UNLIKELY(zip)) {
+	if (UNIV_UNLIKELY(zip_size)) {
 		int	err;
 		d_stream.zalloc = (alloc_func) 0;
 		d_stream.zfree = (free_func) 0;
@@ -4076,12 +4085,36 @@ btr_copy_externally_stored_field(
 #ifdef UNIV_SYNC_DEBUG
 		buf_page_dbg_add_level(page, SYNC_EXTERN_STORAGE);
 #endif /* UNIV_SYNC_DEBUG */
-		if (UNIV_UNLIKELY(zip)) {
+		if (UNIV_UNLIKELY(zip_size)) {
 			int	err;
-			d_stream.next_in = page + 4;
-			d_stream.avail_in = UNIV_PAGE_SIZE - 4;/* TODO */
 
-			page_no = mach_read_from_4(page);
+			if (UNIV_UNLIKELY(fil_page_get_type(page)
+					!= FIL_PAGE_TYPE_ZBLOB)) {
+				ut_print_timestamp(stderr);
+				fprintf(stderr,
+"  InnoDB: Unknown type %lu of compressed BLOB page %lu space %lu\n",
+					(ulong) fil_page_get_type(page),
+					(ulong) page_no, (ulong) space_id);
+			}
+
+			page_no = mach_read_from_4(page + offset);
+
+			if (UNIV_LIKELY(offset == FIL_PAGE_NEXT)) {
+				/* When the BLOB begins at page header,
+				the compressed data payload does not
+				immediately follow the next page pointer. */
+				offset = FIL_PAGE_FILE_FLUSH_LSN;
+			} else {
+				offset += 4;
+			}
+
+			d_stream.next_in = page + offset;
+			d_stream.avail_in = zip_size - offset;
+
+			/* On other BLOB pages except the first
+			the BLOB header always is at the page header: */
+
+			offset = FIL_PAGE_NEXT;
 
 			err = inflate(&d_stream, Z_NO_FLUSH);
 			switch (err) {
@@ -4095,16 +4128,23 @@ btr_copy_externally_stored_field(
 			default:
 				mtr_commit(&mtr);
 				inflateEnd(&d_stream);
-				ut_error;/* TODO: report error */
+inflate_error:
+				ut_print_timestamp(stderr);
+				fprintf(stderr,
+"  InnoDB: inflate() of compressed BLOB page %lu space %lu returned %d\n",
+					(ulong) page_no, (ulong) space_id,
+					err);
+				*len = 0;
 				return(buf);
 			}
 
 			if (page_no == FIL_NULL) {
 				err = inflate(&d_stream, Z_FINISH);
-				/* TODO: report error instead of
-				assertion failure? */
-				ut_a(err == Z_STREAM_END);
-			end_of_blob:
+				if (UNIV_UNLIKELY(err != Z_STREAM_END)) {
+
+					goto inflate_error;
+				}
+end_of_blob:
 				mtr_commit(&mtr);
 				ut_a(!d_stream.avail_out);
 
@@ -4160,8 +4200,9 @@ btr_rec_copy_externally_stored_field(
 	ulint*		len,	/* out: length of the field */
 	mem_heap_t*	heap)	/* in: mem heap */
 {
-	ulint	local_len;
-	byte*	data;
+	ulint		local_len;
+	byte*		data;
+	page_zip_des_t*	page_zip;
 
 	ut_ad(rec_offs_validate(rec, NULL, offsets));
 	ut_a(rec_offs_nth_extern(offsets, no));
@@ -4177,7 +4218,9 @@ btr_rec_copy_externally_stored_field(
 
 	data = rec_get_nth_field(rec, offsets, no, &local_len);
 
+	page_zip = buf_block_get_page_zip(buf_block_align(rec));
+
 	return(btr_copy_externally_stored_field(len, data,
-				!!buf_block_get_page_zip(buf_block_align(rec)),
+				page_zip ? page_zip->size : 0,
 				local_len, heap));
 }

buf/buf0buf.c

@@ -232,6 +232,22 @@ ibool		buf_debug_prints = FALSE; /* If this is set TRUE,
 					the program prints info whenever
 					read-ahead or flush occurs */
 #endif /* UNIV_DEBUG */
+/************************************************************************
+Calculates a compressed BLOB page checksum which is stored to the page
+when it is written to a file. Note that we must be careful to calculate
+the same value on 32-bit and 64-bit architectures. */
+
+ulint
+buf_calc_zblob_page_checksum(
+/*=========================*/
+					/* out: checksum */
+	const byte*	page,		/* in: compressed BLOB page */
+	ulint		zip_size)	/* in: size of the page, in bytes */
+{
+	return(ut_fold_binary(page + FIL_PAGE_SPACE_OR_CHKSUM,
+			zip_size - FIL_PAGE_SPACE_OR_CHKSUM) & 0xFFFFFFFFUL);
+}
+
 /************************************************************************
 Calculates a page checksum which is stored to the page when it is written
 to a file. Note that we must be careful to calculate the same value on
@@ -293,18 +309,19 @@ ibool
 buf_page_is_corrupted(
 /*==================*/
 				/* out: TRUE if corrupted */
-	byte*	read_buf)	/* in: a database page */
+	byte*	read_buf,	/* in: a database page */
+	ulint	zip_size)	/* in: size of compressed page;
+				0 for uncompressed pages */
 {
-	ulint	checksum;
-	ulint	old_checksum;
 	ulint	checksum_field;
 	ulint	old_checksum_field;
 #ifndef UNIV_HOTBACKUP
 	dulint	current_lsn;
 #endif
-	if (mach_read_from_4(read_buf + FIL_PAGE_LSN + 4)
-		!= mach_read_from_4(read_buf + UNIV_PAGE_SIZE
-			- FIL_PAGE_END_LSN_OLD_CHKSUM + 4)) {
+	if (UNIV_LIKELY(!zip_size)
+		&& memcmp(read_buf + FIL_PAGE_LSN + 4,
+			read_buf + UNIV_PAGE_SIZE
+			- FIL_PAGE_END_LSN_OLD_CHKSUM + 4, 4)) {
 
 		/* Stored log sequence numbers at the start and the end
 		of page do not match */
@@ -341,8 +358,16 @@ buf_page_is_corrupted(
 	BUF_NO_CHECKSUM_MAGIC which might be stored by InnoDB with checksums
 	disabled. Otherwise, skip checksum calculation and return FALSE */
 
-	if (srv_use_checksums) {
-		old_checksum = buf_calc_page_old_checksum(read_buf);
+	if (UNIV_LIKELY(srv_use_checksums)) {
+		checksum_field = mach_read_from_4(read_buf
+						+ FIL_PAGE_SPACE_OR_CHKSUM);
+
+		if (UNIV_UNLIKELY(zip_size)) {
+			return(checksum_field != BUF_NO_CHECKSUM_MAGIC
+				&& checksum_field
+				!= buf_calc_zblob_page_checksum(
+						read_buf, zip_size));
+		}
 
 		old_checksum_field = mach_read_from_4(read_buf + UNIV_PAGE_SIZE
 			- FIL_PAGE_END_LSN_OLD_CHKSUM);
@@ -357,21 +382,20 @@ buf_page_is_corrupted(
 
 		if (old_checksum_field != mach_read_from_4(read_buf
 				+ FIL_PAGE_LSN)
-			&& old_checksum_field != old_checksum
-			&& old_checksum_field != BUF_NO_CHECKSUM_MAGIC) {
+				&& old_checksum_field != BUF_NO_CHECKSUM_MAGIC
+				&& old_checksum_field
+				!= buf_calc_page_old_checksum(read_buf)) {
 
 			return(TRUE);
 		}
 
-		checksum = buf_calc_page_new_checksum(read_buf);
-		checksum_field = mach_read_from_4(read_buf +
-			FIL_PAGE_SPACE_OR_CHKSUM);
-
 		/* InnoDB versions < 4.0.14 and < 4.1.1 stored the space id
 		(always equal to 0), to FIL_PAGE_SPACE_SPACE_OR_CHKSUM */
 
-		if (checksum_field != 0 && checksum_field != checksum
-			&& checksum_field != BUF_NO_CHECKSUM_MAGIC) {
+		if (checksum_field != 0
+				&& checksum_field != BUF_NO_CHECKSUM_MAGIC
+				&& checksum_field
+				!= buf_calc_page_new_checksum(read_buf)) {
 
 			return(TRUE);
 		}
@@ -398,6 +422,7 @@ buf_page_print(
 	ut_print_buf(stderr, read_buf, UNIV_PAGE_SIZE);
 	fputs("InnoDB: End of page dump\n", stderr);
 
+	/* TODO: print zipped pages differently, esp. BLOB pages */
 	checksum = srv_use_checksums ?
 		buf_calc_page_new_checksum(read_buf) : BUF_NO_CHECKSUM_MAGIC;
 	old_checksum = srv_use_checksums ?
@@ -489,6 +514,10 @@ buf_page_print(
 		fputs("InnoDB: Page may be a BLOB page\n",
 			stderr);
 		break;
+	case FIL_PAGE_TYPE_ZBLOB:
+		fputs("InnoDB: Page may be a compressed BLOB page\n",
+			stderr);
+		break;
 	}
 }
 
@@ -1885,7 +1914,8 @@ buf_page_io_complete(
 		/* From version 3.23.38 up we store the page checksum
 		to the 4 first bytes of the page end lsn field */
 
-		if (buf_page_is_corrupted(block->frame)) {
+		if (buf_page_is_corrupted(block->frame,
+					block->space ? 16384 : 0/* TODO */)) {
 			fprintf(stderr,
 		"InnoDB: Database page corruption on disk or a failed\n"
 		"InnoDB: file read of page %lu.\n", (ulong) block->offset);

buf/buf0flu.c

@@ -455,6 +455,25 @@ buf_flush_init_for_writing(
 {
 	page_zip_des_t*	page_zip = page_zip_;
 
+	if (space/* TODO: space_is_zip */) {
+		switch (fil_page_get_type(page)) {
+		case FIL_PAGE_TYPE_ZBLOB:
+			ut_ad(!page_zip);
+			mach_write_to_4(page + FIL_PAGE_OFFSET, page_no);
+			mach_write_to_4(page + FIL_PAGE_PREV, space);
+			mach_write_to_8(page + FIL_PAGE_LSN, newest_lsn);
+			mach_write_to_4(page + FIL_PAGE_SPACE_OR_CHKSUM,
+					srv_use_checksums
+					? buf_calc_zblob_page_checksum(
+							page, 16384/* TODO */)
+					: BUF_NO_CHECKSUM_MAGIC);
+			return;
+		case FIL_PAGE_INDEX:
+			/* TODO: special handling */
+			break;
+		}
+	}
+
 	/* Write the newest modification lsn to the page header and trailer */
 	mach_write_to_8(page + FIL_PAGE_LSN, newest_lsn);
 

dict/dict0mem.c

@@ -42,7 +42,7 @@ dict_mem_table_create(
 	mem_heap_t*	heap;
 
 	ut_ad(name);
-	ut_ad(!(flags & ~DICT_TF_COMPACT));
+	ut_ad(!(flags & ~(DICT_TF_COMPACT | DICT_TF_COMPRESSED)));
 
 	heap = mem_heap_create(DICT_HEAP_SIZE);
 

include/btr0btr.h

@@ -207,8 +207,7 @@ btr_page_reorganize(
 				/* out: TRUE on success, FALSE on failure */
 	page_t*		page,	/* in: page to be reorganized */
 	dict_index_t*	index,	/* in: record descriptor */
-	mtr_t*		mtr)	/* in: mtr */
-	__attribute__((nonnull, warn_unused_result));
+	mtr_t*		mtr);	/* in: mtr */
 /*****************************************************************
 Decides if the page should be split at the convergence point of
 inserts converging to left. */

include/buf0buf.h

@@ -390,6 +390,17 @@ buf_block_get_modify_clock(
 				/* out: value */
 	buf_block_t*	block);	/* in: block */
 /************************************************************************
+Calculates a compressed BLOB page checksum which is stored to the page
+when it is written to a file. Note that we must be careful to calculate
+the same value on 32-bit and 64-bit architectures. */
+
+ulint
+buf_calc_zblob_page_checksum(
+/*=========================*/
+					/* out: checksum */
+	const byte*	page,		/* in: compressed BLOB page */
+	ulint		zip_size);	/* in: size of the page, in bytes */
+/************************************************************************
 Calculates a page checksum which is stored to the page when it is written
 to a file. Note that we must be careful to calculate the same value
 on 32-bit and 64-bit architectures. */
@@ -419,7 +430,9 @@ ibool
 buf_page_is_corrupted(
 /*==================*/
 				/* out: TRUE if corrupted */
-	byte*	read_buf);	/* in: a database page */
+	byte*	read_buf,	/* in: a database page */
+	ulint	zip_size);	/* in: size of compressed page;
+				0 for uncompressed pages */
 /**************************************************************************
 Gets the page number of a pointer pointing within a buffer frame containing
 a file page. */

include/fil0fil.h

@@ -105,6 +105,7 @@ extern fil_addr_t	fil_addr_null;
 #define FIL_PAGE_TYPE_FSP_HDR	8	/* File space header */
 #define FIL_PAGE_TYPE_XDES	9	/* Extent descriptor page */
 #define FIL_PAGE_TYPE_BLOB	10	/* Uncompressed BLOB page */
+#define FIL_PAGE_TYPE_ZBLOB	11	/* Compressed BLOB page */
 
 /* Space types */
 #define FIL_TABLESPACE		501

page/page0zip.c

@@ -968,7 +968,8 @@ page_zip_fields_decode(
 		return(NULL);
 	}
 
-	table = dict_mem_table_create("ZIP_DUMMY", DICT_HDR_SPACE, n, TRUE);
+	table = dict_mem_table_create("ZIP_DUMMY", DICT_HDR_SPACE, n,
+				DICT_TF_COMPACT | DICT_TF_COMPRESSED);
 	index = dict_mem_index_create("ZIP_DUMMY", "ZIP_DUMMY",
 				DICT_HDR_SPACE, 0, n);
 	index->table = table;

trx/trx0sys.c

@@ -465,13 +465,21 @@ trx_sys_doublewrite_init_or_restore_pages(
 			/* It is an unwritten doublewrite buffer page:
 			do nothing */
 		} else {
+			ulint	zip_size;
 			/* Read in the actual page from the data files */
 
 			fil_io(OS_FILE_READ, TRUE, space_id, page_no, 0,
 					UNIV_PAGE_SIZE, read_buf, NULL);
 			/* Check if the page is corrupt */
 
-			if (buf_page_is_corrupted(read_buf)) {
+			if (space_id && fil_page_get_type(read_buf)
+					== FIL_PAGE_TYPE_ZBLOB) {
+				zip_size = 16384; /* TODO */
+			} else {
+				zip_size = 0;
+			}
+
+			if (buf_page_is_corrupted(read_buf, zip_size)) {
 
 				fprintf(stderr,
 		"InnoDB: Warning: database page corruption or a failed\n"
@@ -479,7 +487,7 @@ trx_sys_doublewrite_init_or_restore_pages(
 				fprintf(stderr,
 		"InnoDB: Trying to recover it from the doublewrite buffer.\n");
 
-				if (buf_page_is_corrupted(page)) {
+				if (buf_page_is_corrupted(page, zip_size)) {
 					fprintf(stderr,
 		"InnoDB: Dump of the page:\n");
 					buf_page_print(read_buf);