MDEV-35312 page_cur_search_with_match() could avoid rec_get_offsets()

page_cur_search_with_match(): Remove rec_get_offsets(), and instead
determine the start and end of each field while comparing.

page_dir_slot_get_rec(), page_dir_slot_get_rec_validate():
Add a parameter to avoid invoking page_align().

page_cur_dtuple_cmp(): Replaces cmp_dtuple_rec_leaf() for both
leaf and non-leaf pages. In SPATIAL INDEX, non-leaf records are
special, because the child page number may be part of the comparison.

Reviewed by: Vladislav Lesin

storage/innobase/include/page0cur.h

@@ -212,23 +212,18 @@ bool page_apply_delete_dynamic(const buf_block_t &block, ulint prev,
                                size_t hdr_size, size_t data_size);
 
 MY_ATTRIBUTE((warn_unused_result))
-/****************************************************************//**
-Searches the right position for a page cursor. */
-bool
-page_cur_search_with_match(
-/*=======================*/
-	const dtuple_t*		tuple,	/*!< in: data tuple */
-	page_cur_mode_t		mode,	/*!< in: PAGE_CUR_L,
-					PAGE_CUR_LE, PAGE_CUR_G, or
-					PAGE_CUR_GE */
-	uint16_t*		iup_matched_fields,
-					/*!< in/out: already matched
-					fields in upper limit record */
-	uint16_t*		ilow_matched_fields,
-					/*!< in/out: already matched
-					fields in lower limit record */
-	page_cur_t*		cursor,	/*!< in/out: page cursor */
-	rtr_info_t*		rtr_info);/*!< in/out: rtree search stack */
+/** Search the right position for a page cursor.
+@param tuple        search key
+@param mode         search mode
+@param iup_fields   matched fields in the upper limit record
+@param ilow_fields  matched fields in the low limit record
+@param cursor       page cursor
+@param rtr_info     R-tree search stack, or nullptr
+@return whether the page is corrupted */
+bool page_cur_search_with_match(const dtuple_t *tuple, page_cur_mode_t mode,
+                                uint16_t *iup_fields, uint16_t *ilow_fields,
+                                page_cur_t *cursor, rtr_info_t *rtr_info)
+  noexcept;
 
 /** Search the right position for a page cursor.
 @param tuple        search key
@@ -238,7 +233,7 @@ page_cur_search_with_match(
 @param cursor       page cursor
 @param iup_bytes    matched bytes after iup_fields
 @param ilow_bytes   matched bytes after ilow_fields
-@return whether the first partially matched field in the lower limit record,
+@return whether the first partially matched field is in the lower limit record,
 or the page is corrupted */
 bool page_cur_search_with_match_bytes(const dtuple_t &tuple,
                                       page_cur_mode_t mode,

storage/innobase/include/page0page.h

@@ -636,31 +636,55 @@ page_rec_check(
 /** Get the record pointed to by a directory slot.
 @param[in] slot   directory slot
 @return pointer to record */
-inline rec_t *page_dir_slot_get_rec(page_dir_slot_t *slot)
+inline rec_t *page_dir_slot_get_rec(page_t *page, page_dir_slot_t *slot)
+  noexcept
 {
-  return page_align(slot) + mach_read_from_2(my_assume_aligned<2>(slot));
+  return page + mach_read_from_2(my_assume_aligned<2>(slot));
 }
-inline const rec_t *page_dir_slot_get_rec(const page_dir_slot_t *slot)
+inline const rec_t *page_dir_slot_get_rec(const page_t *page,
+                                          const page_dir_slot_t *slot) noexcept
+{
+  return page_dir_slot_get_rec(const_cast<page_t*>(page),
+                               const_cast<rec_t*>(slot));
+}
+
+inline rec_t *page_dir_slot_get_rec(page_dir_slot_t *slot) noexcept
+{
+  return page_dir_slot_get_rec(page_align(slot), slot);
+}
+inline const rec_t *page_dir_slot_get_rec(const page_dir_slot_t *slot) noexcept
 {
   return page_dir_slot_get_rec(const_cast<rec_t*>(slot));
 }
 
-inline rec_t *page_dir_slot_get_rec_validate(page_dir_slot_t *slot)
+inline rec_t *page_dir_slot_get_rec_validate(page_t *page,
+                                             page_dir_slot_t *slot) noexcept
 {
   const size_t s= mach_read_from_2(my_assume_aligned<2>(slot));
-  page_t *page= page_align(slot);
-
   return UNIV_LIKELY(s >= PAGE_NEW_INFIMUM &&
                      s <= page_header_get_field(page, PAGE_HEAP_TOP))
     ? page + s
     : nullptr;
 }
+
+inline const rec_t *page_dir_slot_get_rec_validate(const page_t *page,
+                                                   const page_dir_slot_t *slot)
+  noexcept
+{
+  return page_dir_slot_get_rec_validate(const_cast<page_t*>(page),
+                                        const_cast<page_dir_slot_t*>(slot));
+}
+
+inline rec_t *page_dir_slot_get_rec_validate(page_dir_slot_t *slot) noexcept
+{
+  return page_dir_slot_get_rec_validate(page_align(slot), slot);
+}
 inline const rec_t *page_dir_slot_get_rec_validate(const page_dir_slot_t *slot)
+  noexcept
 {
   return page_dir_slot_get_rec_validate(const_cast<rec_t*>(slot));
 }
 
-
 /***************************************************************//**
 Gets the number of records owned by a directory slot.
 @return number of records */