MDEV-20950 Reduce size of record offsetsbb-10.2-MDEV-20950-stack-offsets

offset_t: this is a type which represents one record offset.
It's unsigned short int.

a lot of functions: replace ulint with offset_t

btr_pcur_restore_position_func(),
page_validate(),
row_ins_scan_sec_index_for_duplicate(),
row_upd_clust_rec_by_insert_inherit_func(),
row_vers_impl_x_locked_low(),
trx_undo_prev_version_build():
  allocate record offsets on the stack instead of waiting for rec_get_offsets()
  to allocate it from mem_heap_t. So, reducing  memory allocations.

RECORD_OFFSET, INDEX_OFFSET:
  now it's less convenient to store pointers in offset_t*
  array. One pointer occupies now several offset_t. And those constant are start
  indexes into array to places where to store pointer values

REC_OFFS_HEADER_SIZE: adjusted for the new reality

REC_OFFS_NORMAL_SIZE:
  increase size from 100 to 300 which means less heap allocations.
  And sizeof(offset_t[REC_OFFS_NORMAL_SIZE]) now is 600 bytes which
  is smaller than previous 800 bytes.

REC_OFFS_SEC_INDEX_SIZE: adjusted for the new reality

rem0rec.h, rem0rec.ic, rem0rec.cc:
  various arguments, return values and local variables types were changed to
  fix numerous integer conversions issues.

enum field_type_t:
  offset types concept was introduces which replaces old offset flags stuff.
  Like in earlier version, 2 upper bits are used to store offset type.
  And this enum represents those types.

REC_OFFS_SQL_NULL, REC_OFFS_MASK: removed

get_type(), set_type(), get_value(), combine():
  these are convenience functions to work with offsets and it's types

rec_offs_base()[0]:
  still uses an old scheme with flags REC_OFFS_COMPACT and REC_OFFS_EXTERNAL

rec_offs_base()[i]:
  these have type offset_t now. Two upper bits contains type.

1 files changed, 3 insertions, 3 deletions

diff --git a/storage/innobase/include/row0vers.h b/storage/innobase/include/row0vers.h
index 327bb546356..2a76e27e226 100644
--- a/storage/innobase/include/row0vers.h
+++ b/storage/innobase/include/row0vers.h
@@ -50,7 +50,7 @@ trx_t*
 row_vers_impl_x_locked(
 	const rec_t*	rec,
 	dict_index_t*	index,
-	const ulint*	offsets);
+	const offset_t*	offsets);
 
 /*****************************************************************//**
 Finds out if we must preserve a delete marked earlier version of a clustered
@@ -112,7 +112,7 @@ row_vers_build_for_consistent_read(
 	mtr_t*		mtr,	/*!< in: mtr holding the latch on rec; it will
 				also hold the latch on purge_view */
 	dict_index_t*	index,	/*!< in: the clustered index */
-	ulint**		offsets,/*!< in/out: offsets returned by
+	offset_t**	offsets,/*!< in/out: offsets returned by
 				rec_get_offsets(rec, index) */
 	ReadView*	view,	/*!< in: the consistent read view */
 	mem_heap_t**	offset_heap,/*!< in/out: memory heap from which
@@ -139,7 +139,7 @@ row_vers_build_for_semi_consistent_read(
 				of this records */
 	mtr_t*		mtr,	/*!< in: mtr holding the latch on rec */
 	dict_index_t*	index,	/*!< in: the clustered index */
-	ulint**		offsets,/*!< in/out: offsets returned by
+	offset_t**	offsets,/*!< in/out: offsets returned by
 				rec_get_offsets(rec, index) */
 	mem_heap_t**	offset_heap,/*!< in/out: memory heap from which
 				the offsets are allocated */