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, 4 insertions, 3 deletions

diff --git a/storage/innobase/include/btr0btr.h b/storage/innobase/include/btr0btr.h
index ee4e522cf49..c5ae633016a 100644
--- a/storage/innobase/include/btr0btr.h
+++ b/storage/innobase/include/btr0btr.h
@@ -30,6 +30,7 @@ Created 6/2/1994 Heikki Tuuri
 
 #include "dict0dict.h"
 #include "data0data.h"
+#include "rem0types.h"
 #include "page0cur.h"
 #include "btr0types.h"
 #include "gis0type.h"
@@ -305,7 +306,7 @@ ulint
 btr_node_ptr_get_child_page_no(
 /*===========================*/
 	const rec_t*	rec,	/*!< in: node pointer record */
-	const ulint*	offsets)/*!< in: array returned by rec_get_offsets() */
+	const offset_t*	offsets)/*!< in: array returned by rec_get_offsets() */
 	MY_ATTRIBUTE((warn_unused_result));
 
 /** Create the root node for a new index tree.
@@ -392,7 +393,7 @@ btr_root_raise_and_insert(
 				on the root page; when the function returns,
 				the cursor is positioned on the predecessor
 				of the inserted record */
-	ulint**		offsets,/*!< out: offsets on inserted record */
+	offset_t**	offsets,/*!< out: offsets on inserted record */
 	mem_heap_t**	heap,	/*!< in/out: pointer to memory heap
 				that can be emptied, or NULL */
 	const dtuple_t*	tuple,	/*!< in: tuple to insert */
@@ -475,7 +476,7 @@ btr_page_split_and_insert(
 	btr_cur_t*	cursor,	/*!< in: cursor at which to insert; when the
 				function returns, the cursor is positioned
 				on the predecessor of the inserted record */
-	ulint**		offsets,/*!< out: offsets on inserted record */
+	offset_t**	offsets,/*!< out: offsets on inserted record */
 	mem_heap_t**	heap,	/*!< in/out: pointer to memory heap
 				that can be emptied, or NULL */
 	const dtuple_t*	tuple,	/*!< in: tuple to insert */