1 files changed, 129 insertions, 0 deletions
diff --git a/storage/innobase/include/trx0undo.inl b/storage/innobase/include/trx0undo.inl
new file mode 100644
index 00000000..9f05989f
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+++ b/storage/innobase/include/trx0undo.inl
@@ -0,0 +1,129 @@
+/*****************************************************************************
+
+Copyright (c) 1996, 2013, Oracle and/or its affiliates. All Rights Reserved.
+Copyright (c) 2017, 2022, MariaDB Corporation.
+
+This program is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free Software
+Foundation; version 2 of the License.
+
+This program is distributed in the hope that it will be useful, but WITHOUT
+ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along with
+this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA
+
+*****************************************************************************/
+
+/**************************************************//**
+@file include/trx0undo.ic
+Transaction undo log
+
+Created 3/26/1996 Heikki Tuuri
+*******************************************************/
+
+#include "data0type.h"
+#include "page0page.h"
+
+/***********************************************************************//**
+Builds a roll pointer.
+@return roll pointer */
+UNIV_INLINE
+roll_ptr_t
+trx_undo_build_roll_ptr(
+/*====================*/
+	bool	is_insert,	/*!< in: TRUE if insert undo log */
+	ulint	rseg_id,	/*!< in: rollback segment id */
+	uint32_t page_no,	/*!< in: page number */
+	uint16_t offset)		/*!< in: offset of the undo entry within page */
+{
+  compile_time_assert(DATA_ROLL_PTR_LEN == 7);
+  ut_ad(rseg_id < TRX_SYS_N_RSEGS);
+
+  return roll_ptr_t{is_insert} << ROLL_PTR_INSERT_FLAG_POS |
+    roll_ptr_t{rseg_id} << ROLL_PTR_RSEG_ID_POS |
+    roll_ptr_t{page_no} << ROLL_PTR_PAGE_POS | offset;
+}
+
+/***********************************************************************//**
+Decodes a roll pointer. */
+UNIV_INLINE
+void
+trx_undo_decode_roll_ptr(
+/*=====================*/
+	roll_ptr_t	roll_ptr,	/*!< in: roll pointer */
+	bool*		is_insert,	/*!< out: TRUE if insert undo log */
+	ulint*		rseg_id,	/*!< out: rollback segment id */
+	uint32_t*	page_no,	/*!< out: page number */
+	uint16_t*	offset)		/*!< out: offset of the undo
+					entry within page */
+{
+  compile_time_assert(DATA_ROLL_PTR_LEN == 7);
+  ut_ad(roll_ptr < (1ULL << 56));
+  *offset= static_cast<uint16_t>(roll_ptr);
+  *page_no= static_cast<uint32_t>(roll_ptr >> 16);
+  *rseg_id= static_cast<ulint>(roll_ptr >> 48 & 0x7F);
+  *is_insert= static_cast<bool>(roll_ptr >> 55);
+}
+
+/***********************************************************************//**
+Determine if DB_ROLL_PTR is of the insert type.
+@return true if insert */
+UNIV_INLINE
+bool
+trx_undo_roll_ptr_is_insert(
+/*========================*/
+	roll_ptr_t	roll_ptr)	/*!< in: roll pointer */
+{
+	compile_time_assert(DATA_ROLL_PTR_LEN == 7);
+	ut_ad(roll_ptr < (1ULL << (ROLL_PTR_INSERT_FLAG_POS + 1)));
+	return static_cast<bool>(roll_ptr >> ROLL_PTR_INSERT_FLAG_POS);
+}
+
+/***********************************************************************//**
+Returns true if the record is of the insert type.
+@return true if the record was freshly inserted (not updated). */
+UNIV_INLINE
+bool
+trx_undo_trx_id_is_insert(
+/*======================*/
+	const byte*	trx_id)	/*!< in: DB_TRX_ID, followed by DB_ROLL_PTR */
+{
+	compile_time_assert(DATA_TRX_ID + 1 == DATA_ROLL_PTR);
+	return bool(trx_id[DATA_TRX_ID_LEN] >> 7);
+}
+
+/** Determine the end offset of undo log records of an undo log page.
+@param[in]	undo_page	undo log page
+@param[in]	page_no		undo log header page number
+@param[in]	offset		undo log header offset
+@return end offset */
+inline
+uint16_t trx_undo_page_get_end(const buf_block_t *undo_page, uint32_t page_no,
+                               uint16_t offset)
+{
+  if (page_no == undo_page->page.id().page_no())
+    if (uint16_t end = mach_read_from_2(TRX_UNDO_NEXT_LOG + offset +
+					undo_page->page.frame))
+      return end;
+
+  return mach_read_from_2(TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_FREE +
+			  undo_page->page.frame);
+}
+
+/** Get the next record in an undo log.
+@param[in]      undo_page       undo log page
+@param[in]      rec             undo record offset in the page
+@param[in]      page_no         undo log header page number
+@param[in]      offset          undo log header offset on page
+@return undo log record, the page latched, NULL if none */
+inline trx_undo_rec_t*
+trx_undo_page_get_next_rec(const buf_block_t *undo_page, uint16_t rec,
+                           uint32_t page_no, uint16_t offset)
+{
+  uint16_t end= trx_undo_page_get_end(undo_page, page_no, offset);
+  uint16_t next= mach_read_from_2(undo_page->page.frame + rec);
+  return next == end ? nullptr : undo_page->page.frame + next;
+}