branches/zip: Implement the compression of BLOB columns.

This has not been extensively tested yet, because some other part of the
code breaks in "ibtestblob".

btr_free_page_low(): Add parameters "space" and "page_no", because they
are omitted from compressed BLOB pages.

btr0cur.c: Implement the compression and decompression of BLOB columns,
enabled at compile-time (#define ZIP_BLOB TRUE) for now.

btr_rec_free_externally_stored_fields(),
btr_copy_externally_stored_field(): Made static

mlog_log_string(): New function, split from mlog_write_string(), allows
to avoid a dummy memcpy() of compressed BLOB pages.

btr/btr0btr.c

@@ -436,13 +436,13 @@ btr_page_free_low(
 /*==============*/
 	dict_tree_t*	tree,	/* in: index tree */
 	page_t*		page,	/* in: page to be freed, x-latched */	
+	ulint		space,	/* in: space */
+	ulint		page_no,/* in: page number */
 	ulint		level,	/* in: page level */
 	mtr_t*		mtr)	/* in: mtr */
 {
 	fseg_header_t*	seg_header;
 	page_t*		root;
-	ulint		space;
-	ulint		page_no;
 
 	ut_ad(mtr_memo_contains(mtr, buf_block_align(page),
 			      				MTR_MEMO_PAGE_X_FIX));
@@ -466,9 +466,6 @@ btr_page_free_low(
 		seg_header = root + PAGE_HEADER + PAGE_BTR_SEG_TOP;
 	}
 
-	space = buf_frame_get_space_id(page);
-	page_no = buf_frame_get_page_no(page);
-	
 	fseg_free_page(seg_header, space, page_no, mtr);
 }	
 
@@ -484,12 +481,17 @@ btr_page_free(
 	mtr_t*		mtr)	/* in: mtr */
 {
 	ulint		level;
+	ulint		space;
+	ulint		page_no;
 
 	ut_ad(mtr_memo_contains(mtr, buf_block_align(page),
 			      				MTR_MEMO_PAGE_X_FIX));
 	level = btr_page_get_level(page, mtr);
 	
-	btr_page_free_low(tree, page, level, mtr);
+	space = buf_frame_get_space_id(page);
+	page_no = buf_frame_get_page_no(page);
+	
+	btr_page_free_low(tree, page, space, page_no, level, mtr);
 }	
 
 /******************************************************************

include/btr0btr.h

@@ -392,6 +392,8 @@ btr_page_free_low(
 /*==============*/
 	dict_tree_t*	tree,	/* in: index tree */
 	page_t*		page,	/* in: page to be freed, x-latched */	
+	ulint		space,	/* in: space */
+	ulint		page_no,/* in: page number */
 	ulint		level,	/* in: page level */
 	mtr_t*		mtr);	/* in: mtr */
 #ifdef UNIV_BTR_PRINT

include/btr0cur.h

@@ -493,24 +493,6 @@ btr_free_externally_stored_field(
 	mtr_t*		local_mtr);	/* in: mtr containing the latch to
 					data an an X-latch to the index
 					tree */
-/***************************************************************
-Frees the externally stored fields for a record. */
-
-void
-btr_rec_free_externally_stored_fields(
-/*==================================*/
-	dict_index_t*	index,	/* in: index of the data, the index
-				tree MUST be X-latched */
-	rec_t*		rec,	/* in: record */
-	const ulint*	offsets,/* in: rec_get_offsets(rec, index) */
-	page_zip_des_t*	page_zip,/* in: compressed page whose uncompressed
-				part will be updated, or NULL */
-	ibool		do_not_free_inherited,/* in: TRUE if called in a
-				rollback and we do not want to free
-				inherited fields */
-	mtr_t*		mtr);	/* in: mini-transaction handle which contains
-				an X-latch to record page and to the index
-				tree */
 /***********************************************************************
 Copies an externally stored field of a record to mem heap. */
 
@@ -524,22 +506,6 @@ btr_rec_copy_externally_stored_field(
 	ulint*		len,	/* out: length of the field */
 	mem_heap_t*	heap);	/* in: mem heap */
 /***********************************************************************
-Copies an externally stored field of a record to mem heap. Parameter
-data contains a pointer to 'internally' stored part of the field:
-possibly some data, and the reference to the externally stored part in
-the last 20 bytes of data. */
-
-byte*
-btr_copy_externally_stored_field(
-/*=============================*/
-				/* out: the whole field copied to heap */
-	ulint*		len,	/* out: length of the whole field */
-	byte*		data,	/* in: 'internally' stored part of the
-				field containing also the reference to
-				the external part */
-	ulint		local_len,/* in: length of data */
-	mem_heap_t*	heap);	/* in: mem heap */
-/***********************************************************************
 Stores the positions of the fields marked as extern storage in the update
 vector, and also those fields who are marked as extern storage in rec
 and not mentioned in updated fields. We use this function to remember

include/mtr0log.h

@@ -46,6 +46,16 @@ mlog_write_string(
 	ulint		len,	/* in: string length */
 	mtr_t*		mtr);	/* in: mini-transaction handle */
 /************************************************************
+Logs a write of a string to a file page buffered in the buffer pool.
+Writes the corresponding log record to the mini-transaction log. */
+
+void
+mlog_log_string(
+/*============*/
+	byte*	ptr,	/* in: pointer written to */
+	ulint	len,	/* in: string length */
+	mtr_t*	mtr);	/* in: mini-transaction handle */
+/************************************************************
 Writes initial part of a log record consisting of one-byte item
 type and four-byte space and page numbers. */
 

mtr/mtr0log.c

@@ -307,8 +307,6 @@ mlog_write_string(
 	ulint		len,	/* in: string length */
 	mtr_t*		mtr)	/* in: mini-transaction handle */
 {
-	byte*	log_ptr;
-
 	if (UNIV_UNLIKELY(ptr < buf_pool->frame_zero)
 	    || UNIV_UNLIKELY(ptr >= buf_pool->high_end)) {
 		fprintf(stderr,
@@ -318,7 +316,26 @@ mlog_write_string(
 	ut_ad(ptr && mtr);
 	ut_a(len < UNIV_PAGE_SIZE);
 
-	ut_memcpy(ptr, str, len);
+	memcpy(ptr, str, len);
+
+	mlog_log_string(ptr, len, mtr);
+}
+
+/************************************************************
+Logs a write of a string to a file page buffered in the buffer pool.
+Writes the corresponding log record to the mini-transaction log. */
+
+void
+mlog_log_string(
+/*============*/
+	byte*	ptr,	/* in: pointer written to */
+	ulint	len,	/* in: string length */
+	mtr_t*	mtr)	/* in: mini-transaction handle */
+{
+	byte*	log_ptr;
+
+	ut_ad(ptr && mtr);
+	ut_ad(len <= UNIV_PAGE_SIZE);
 
 	log_ptr = mlog_open(mtr, 30);
 	
@@ -330,7 +347,7 @@ mlog_write_string(
 
 	log_ptr = mlog_write_initial_log_record_fast(ptr, MLOG_WRITE_STRING,
 								log_ptr, mtr);
-	mach_write_to_2(log_ptr, ptr - buf_frame_align(ptr));
+	mach_write_to_2(log_ptr, ut_align_offset(ptr, UNIV_PAGE_SIZE));
 	log_ptr += 2;
 	
 	mach_write_to_2(log_ptr, len);
@@ -338,7 +355,7 @@ mlog_write_string(
 
 	mlog_close(mtr, log_ptr);
 
-	mlog_catenate_string(mtr, str, len);
+	mlog_catenate_string(mtr, ptr, len);
 }
 
 /************************************************************