Cleanup: Remove mach_read_ulint()

The function mach_read_ulint() is a wrapper for the lower-level
functions mach_read_from_1(), mach_read_from_2(), mach_read_from_8().
Invoke those functions directly, for better readability of the code.

mtr_t::read_ulint(), mtr_read_ulint(): Remove. Yes, we will lose the
ability to assert that the read is covered by the mini-transaction.
We would still check that on writes, and any writes that
wrongly bypass mini-transaction logging would likely be caught by
stress testing with Mariabackup.

12 files changed, 34 insertions, 129 deletions

diff --git a/extra/mariabackup/xtrabackup.cc b/extra/mariabackup/xtrabackup.cc
index f695b5c7f6d..3ddd8786ee9 100644
--- a/extra/mariabackup/xtrabackup.cc
+++ b/extra/mariabackup/xtrabackup.cc
@@ -3343,9 +3343,9 @@ retry:
 			       + TRX_SYS_RSEG_PAGE_NO + page)
 	      != FIL_NULL);
 
-	space = mach_read_ulint(TRX_SYS + TRX_SYS_RSEGS
-				+ TRX_SYS_RSEG_SLOT_SIZE
-				+ TRX_SYS_RSEG_SPACE + page, MLOG_4BYTES);
+	space = mach_read_from_4(TRX_SYS + TRX_SYS_RSEGS
+				 + TRX_SYS_RSEG_SLOT_SIZE
+				 + TRX_SYS_RSEG_SPACE + page);
 
 	srv_undo_space_id_start = space;
 
diff --git a/storage/innobase/dict/dict0crea.cc b/storage/innobase/dict/dict0crea.cc
index c142dd382a7..1a6c38a6651 100644
--- a/storage/innobase/dict/dict0crea.cc
+++ b/storage/innobase/dict/dict0crea.cc
@@ -920,7 +920,7 @@ dict_drop_index_tree(
 
 	btr_pcur_store_position(pcur, mtr);
 
-	root_page_no = mtr_read_ulint(ptr, MLOG_4BYTES, mtr);
+	root_page_no = mach_read_from_4(ptr);
 
 	if (root_page_no == FIL_NULL) {
 		/* The tree has already been freed */
@@ -936,7 +936,7 @@ dict_drop_index_tree(
 
 	ut_ad(len == 4);
 
-	space = mtr_read_ulint(ptr, MLOG_4BYTES, mtr);
+	space = mach_read_from_4(ptr);
 
 	ptr = rec_get_nth_field_old(
 		rec, DICT_FLD__SYS_INDEXES__ID, &len);
diff --git a/storage/innobase/dict/dict0load.cc b/storage/innobase/dict/dict0load.cc
index 27b3f5f2e5c..7d58bffc46f 100644
--- a/storage/innobase/dict/dict0load.cc
+++ b/storage/innobase/dict/dict0load.cc
@@ -1484,11 +1484,10 @@ void dict_check_tablespaces_and_store_max_id()
 	dict_sys_lock();
 
 	/* Initialize the max space_id from sys header */
-	mtr_start(&mtr);
-	ulint	max_space_id = mtr_read_ulint(
-		dict_hdr_get(&mtr) + DICT_HDR_MAX_SPACE_ID,
-		MLOG_4BYTES, &mtr);
-	mtr_commit(&mtr);
+	mtr.start();
+	ulint max_space_id = mach_read_from_4(DICT_HDR_MAX_SPACE_ID
+					      + dict_hdr_get(&mtr));
+	mtr.commit();
 
 	fil_set_max_space_id_if_bigger(max_space_id);
 
diff --git a/storage/innobase/fsp/fsp0fsp.cc b/storage/innobase/fsp/fsp0fsp.cc
index dec1f0cecca..3b324b6c437 100644
--- a/storage/innobase/fsp/fsp0fsp.cc
+++ b/storage/innobase/fsp/fsp0fsp.cc
@@ -1386,8 +1386,7 @@ static void fsp_free_page(fil_space_t* space, page_no_t offset,
 	xdes_set_bit(descr, XDES_FREE_BIT, bit, TRUE, mtr);
 	xdes_set_bit(descr, XDES_CLEAN_BIT, bit, TRUE, mtr);
 
-	frag_n_used = mtr_read_ulint(header + FSP_FRAG_N_USED, MLOG_4BYTES,
-				     mtr);
+	frag_n_used = mach_read_from_4(header + FSP_FRAG_N_USED);
 	if (state == XDES_FULL_FRAG) {
 		/* The fragment was full: move it to another list */
 		flst_remove(header + FSP_FULL_FRAG, descr + XDES_FLST_NODE,
@@ -2610,8 +2609,7 @@ try_again:
 	n_free_list_ext = flst_get_len(space_header + FSP_FREE);
 	ut_ad(space->free_len == n_free_list_ext);
 
-	free_limit = mtr_read_ulint(space_header + FSP_FREE_LIMIT,
-				    MLOG_4BYTES, mtr);
+	free_limit = mach_read_from_4(space_header + FSP_FREE_LIMIT);
 	ut_ad(space->free_limit == free_limit);
 
 	/* Below we play safe when counting free extents above the free limit:
@@ -2693,9 +2691,7 @@ fseg_mark_page_used(
 	ut_ad(!((page_offset(seg_inode) - FSEG_ARR_OFFSET) % FSEG_INODE_SIZE));
 	ut_ad(mach_read_from_4(seg_inode + FSEG_MAGIC_N)
 	      == FSEG_MAGIC_N_VALUE);
-
-	ut_ad(mtr_read_ulint(seg_inode + FSEG_ID, MLOG_4BYTES, mtr)
-	      == mtr_read_ulint(descr + XDES_ID, MLOG_4BYTES, mtr));
+	ut_ad(!memcmp(seg_inode + FSEG_ID, descr + XDES_ID, 4));
 
 	if (xdes_is_free(descr, mtr)) {
 		/* We move the extent from the free list to the
@@ -2712,8 +2708,7 @@ fseg_mark_page_used(
 	/* We mark the page as used */
 	xdes_set_bit(descr, XDES_FREE_BIT, page % FSP_EXTENT_SIZE, FALSE, mtr);
 
-	not_full_n_used = mtr_read_ulint(seg_inode + FSEG_NOT_FULL_N_USED,
-					 MLOG_4BYTES, mtr);
+	not_full_n_used = mach_read_from_4(seg_inode + FSEG_NOT_FULL_N_USED);
 	not_full_n_used++;
 	mlog_write_ulint(seg_inode + FSEG_NOT_FULL_N_USED, not_full_n_used,
 			 MLOG_4BYTES, mtr);
@@ -2825,8 +2820,7 @@ fseg_free_page_low(
 			<< FORCE_RECOVERY_MSG;
 	}
 
-	not_full_n_used = mtr_read_ulint(seg_inode + FSEG_NOT_FULL_N_USED,
-					 MLOG_4BYTES, mtr);
+	not_full_n_used = mach_read_from_4(seg_inode + FSEG_NOT_FULL_N_USED);
 	if (xdes_is_full(descr, mtr)) {
 		/* The fragment is full: move it to another list */
 		flst_remove(seg_inode + FSEG_FULL,
@@ -2991,9 +2985,8 @@ fseg_free_extent(
 		flst_remove(seg_inode + FSEG_NOT_FULL,
 			    descr + XDES_FLST_NODE, mtr);
 
-		not_full_n_used = mtr_read_ulint(
-			seg_inode + FSEG_NOT_FULL_N_USED, MLOG_4BYTES, mtr);
-
+		not_full_n_used = mach_read_from_4(FSEG_NOT_FULL_N_USED
+						   + seg_inode);
 		descr_n_used = xdes_get_n_used(descr, mtr);
 		ut_a(not_full_n_used >= descr_n_used);
 		mlog_write_ulint(seg_inode + FSEG_NOT_FULL_N_USED,
@@ -3234,9 +3227,7 @@ fseg_print_low(
 	reserved = fseg_n_reserved_pages_low(inode, &used, mtr);
 
 	seg_id = mach_read_from_8(inode + FSEG_ID);
-
-	n_used = mtr_read_ulint(inode + FSEG_NOT_FULL_N_USED,
-				MLOG_4BYTES, mtr);
+	n_used = mach_read_from_4(inode + FSEG_NOT_FULL_N_USED);
 	n_frag = fseg_get_n_frag_pages(inode, mtr);
 	n_free = flst_get_len(inode + FSEG_FREE);
 	n_not_full = flst_get_len(inode + FSEG_NOT_FULL);
@@ -3275,23 +3266,12 @@ fseg_print(
 #endif /* UNIV_BTR_PRINT */
 
 #ifdef UNIV_DEBUG
-/** Print the file segment header to the given output stream.
-@param[in]	out	the output stream into which the object is printed.
-@retval	the output stream into which the object was printed. */
-std::ostream&
-fseg_header::to_stream(std::ostream&	out) const
+std::ostream &fseg_header::to_stream(std::ostream &out) const
 {
-	const ulint	space = mtr_read_ulint(m_header + FSEG_HDR_SPACE,
-					       MLOG_4BYTES, m_mtr);
-	const ulint	page_no = mtr_read_ulint(m_header + FSEG_HDR_PAGE_NO,
-						 MLOG_4BYTES, m_mtr);
-
-	const ulint	offset = mtr_read_ulint(m_header + FSEG_HDR_OFFSET,
-						 MLOG_2BYTES, m_mtr);
-
-	out << "[fseg_header_t: space=" << space << ", page="
-		<< page_no << ", offset=" << offset << "]";
-
-	return(out);
+  out << "[fseg_header_t: space="
+      << mach_read_from_4(m_header + FSEG_HDR_SPACE)
+      << ", page=" << mach_read_from_4(m_header + FSEG_HDR_PAGE_NO)
+      << ", offset=" << mach_read_from_2(m_header + FSEG_HDR_OFFSET) << "]";
+  return out;
 }
 #endif /* UNIV_DEBUG */
diff --git a/storage/innobase/fts/fts0fts.cc b/storage/innobase/fts/fts0fts.cc
index 82e7130370e..a8b282198a6 100644
--- a/storage/innobase/fts/fts0fts.cc
+++ b/storage/innobase/fts/fts0fts.cc
@@ -3625,8 +3625,7 @@ fts_read_ulint(
 	dfield_t*	dfield = que_node_get_val(exp);
 	void*		data = dfield_get_data(dfield);
 
-	*value = static_cast<ulint>(mach_read_from_4(
-		static_cast<const byte*>(data)));
+	*value = mach_read_from_4(static_cast<const byte*>(data));
 
 	return(TRUE);
 }
diff --git a/storage/innobase/include/fsp0fsp.ic b/storage/innobase/include/fsp0fsp.ic
index 731e0e7ea77..31b9d8c5dbe 100644
--- a/storage/innobase/include/fsp0fsp.ic
+++ b/storage/innobase/include/fsp0fsp.ic
@@ -44,8 +44,5 @@ xdes_get_bit(
 	ulint	bit_index = index % 8;
 	ulint	byte_index = index / 8;
 
-	return(ut_bit_get_nth(
-			mach_read_ulint(descr + XDES_BITMAP + byte_index,
-					MLOG_1BYTE),
-			bit_index));
+	return ut_bit_get_nth(descr[XDES_BITMAP + byte_index], bit_index);
 }
diff --git a/storage/innobase/include/fut0lst.ic b/storage/innobase/include/fut0lst.ic
index 56627be46eb..0a4f2b24738 100644
--- a/storage/innobase/include/fut0lst.ic
+++ b/storage/innobase/include/fut0lst.ic
@@ -1,6 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 1995, 2014, Oracle and/or its affiliates. All Rights Reserved.
+Copyright (c) 2019, 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
@@ -61,9 +62,8 @@ flst_read_addr(
 
 	ut_ad(faddr && mtr);
 
-	addr.page = mtr_read_ulint(faddr + FIL_ADDR_PAGE, MLOG_4BYTES, mtr);
-	addr.boffset = mtr_read_ulint(faddr + FIL_ADDR_BYTE, MLOG_2BYTES,
-				      mtr);
+	addr.page = mach_read_from_4(faddr + FIL_ADDR_PAGE);
+	addr.boffset = mach_read_from_2(faddr + FIL_ADDR_BYTE);
 	ut_a(addr.page == FIL_NULL || addr.boffset >= FIL_PAGE_DATA);
 	ut_a(ut_align_offset(faddr, srv_page_size) >= FIL_PAGE_DATA);
 	return(addr);
diff --git a/storage/innobase/include/mach0data.h b/storage/innobase/include/mach0data.h
index a5d9af07f3b..3d0e48253eb 100644
--- a/storage/innobase/include/mach0data.h
+++ b/storage/innobase/include/mach0data.h
@@ -1,7 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 1995, 2016, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2017, MariaDB Corporation.
+Copyright (c) 2017, 2019, 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
@@ -367,17 +367,6 @@ mach_write_ulonglong(
 
 #endif /* !UNIV_INNOCHECKSUM */
 
-/** Read 1 to 4 bytes from a file page buffered in the buffer pool.
-@param[in]	ptr	pointer where to read
-@param[in]	type	MLOG_1BYTE, MLOG_2BYTES, or MLOG_4BYTES
-@return value read */
-UNIV_INLINE
-ulint
-mach_read_ulint(
-	const byte*	ptr,
-	mlog_id_t	type)
-	MY_ATTRIBUTE((warn_unused_result));
-
 #include "mach0data.ic"
 
 #endif
diff --git a/storage/innobase/include/mach0data.ic b/storage/innobase/include/mach0data.ic
index 408044292a5..80bd925d70b 100644
--- a/storage/innobase/include/mach0data.ic
+++ b/storage/innobase/include/mach0data.ic
@@ -1,7 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 1995, 2015, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2017, MariaDB Corporation.
+Copyright (c) 2017, 2019, 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
@@ -866,28 +866,3 @@ mach_write_ulonglong(
 }
 
 #endif /* !UNIV_INNOCHECKSUM */
-
-/** Read 1 to 4 bytes from a file page buffered in the buffer pool.
-@param[in]	ptr	pointer where to read
-@param[in]	type	MLOG_1BYTE, MLOG_2BYTES, or MLOG_4BYTES
-@return value read */
-UNIV_INLINE
-ulint
-mach_read_ulint(
-	const byte*	ptr,
-	mlog_id_t	type)
-{
-	switch (type) {
-	case MLOG_1BYTE:
-		return(mach_read_from_1(ptr));
-	case MLOG_2BYTES:
-		return(mach_read_from_2(ptr));
-	case MLOG_4BYTES:
-		return(mach_read_from_4(ptr));
-	default:
-		break;
-	}
-
-	ut_error;
-	return(0);
-}
diff --git a/storage/innobase/include/mtr0mtr.h b/storage/innobase/include/mtr0mtr.h
index 4b41506d339..63878773e05 100644
--- a/storage/innobase/include/mtr0mtr.h
+++ b/storage/innobase/include/mtr0mtr.h
@@ -2,7 +2,7 @@
 
 Copyright (c) 1995, 2017, Oracle and/or its affiliates. All Rights Reserved.
 Copyright (c) 2012, Facebook Inc.
-Copyright (c) 2013, 2018, MariaDB Corporation.
+Copyright (c) 2013, 2019, 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
@@ -54,10 +54,6 @@ savepoint. */
 @return	old mode */
 #define mtr_set_log_mode(m, d)	(m)->set_log_mode((d))
 
-/** Read 1 - 4 bytes from a file page buffered in the buffer pool.
-@return	value read */
-#define mtr_read_ulint(p, t, m)	(m)->read_ulint((p), (t))
-
 /** Release an object in the memo stack.
 @return true if released */
 #define mtr_memo_release(m, o, t)					\
@@ -306,13 +302,6 @@ struct mtr_t {
 	bool is_named_space(const fil_space_t* space) const;
 #endif /* UNIV_DEBUG */
 
-	/** Read 1 - 4 bytes from a file page buffered in the buffer pool.
-	@param ptr	pointer from where to read
-	@param type)	MLOG_1BYTE, MLOG_2BYTES, MLOG_4BYTES
-	@return	value read */
-	inline ulint read_ulint(const byte* ptr, mlog_id_t type) const
-		MY_ATTRIBUTE((warn_unused_result));
-
 	/** Locks a rw-latch in S mode.
 	NOTE: use mtr_s_lock().
 	@param lock	rw-lock
diff --git a/storage/innobase/include/mtr0mtr.ic b/storage/innobase/include/mtr0mtr.ic
index 9a83badc173..99057303c90 100644
--- a/storage/innobase/include/mtr0mtr.ic
+++ b/storage/innobase/include/mtr0mtr.ic
@@ -275,21 +275,3 @@ mtr_t::sx_lock(rw_lock_t* lock, const char* file, unsigned line)
 
 	memo_push(lock, MTR_MEMO_SX_LOCK);
 }
-
-/**
-Reads 1 - 4 bytes from a file page buffered in the buffer pool.
-@return	value read */
-
-ulint
-mtr_t::read_ulint(const byte* ptr, mlog_id_t type) const
-{
-	ut_ad(is_active());
-
-	ut_ad(memo_contains_page_flagged(
-			ptr,
-			MTR_MEMO_PAGE_S_FIX
-			| MTR_MEMO_PAGE_X_FIX
-			| MTR_MEMO_PAGE_SX_FIX));
-
-	return(mach_read_ulint(ptr, type));
-}
diff --git a/storage/innobase/row/row0import.cc b/storage/innobase/row/row0import.cc
index 9d48d90c962..104f142b807 100644
--- a/storage/innobase/row/row0import.cc
+++ b/storage/innobase/row/row0import.cc
@@ -466,17 +466,12 @@ protected:
 		UT_DELETE_ARRAY(m_xdes);
 		m_xdes = NULL;
 
-		ulint		state;
-		const xdes_t*	xdesc = page + XDES_ARR_OFFSET;
-
-		state = mach_read_ulint(xdesc + XDES_STATE, MLOG_4BYTES);
-
-		if (state != XDES_FREE) {
+		if (mach_read_from_4(XDES_ARR_OFFSET + XDES_STATE + page)
+		    != XDES_FREE) {
 			const ulint physical_size = m_zip_size
 				? m_zip_size : srv_page_size;
 
-			m_xdes = UT_NEW_ARRAY_NOKEY(xdes_t,
-						    physical_size);
+			m_xdes = UT_NEW_ARRAY_NOKEY(xdes_t, physical_size);
 
 			/* Trigger OOM */
 			DBUG_EXECUTE_IF(