MDEV-21511: Remove unnecessary code

Now that we will be invoking dtuple_get_n_ext() instead of
letting btr_push_update_extern_fields() update an already
calculated value, it is unnecessary to calculate the n_ext
upfront.

row_rec_to_index_entry(), row_rec_to_index_entry_low():
Remove the output parameter n_ext.

storage/innobase/btr/btr0cur.cc

@@ -3969,7 +3969,6 @@ btr_cur_optimistic_update(
 	dtuple_t*	new_entry;
 	roll_ptr_t	roll_ptr;
 	ulint		i;
-	ulint		n_ext;
 
 	block = btr_cur_get_block(cursor);
 	page = buf_block_get_frame(block);
@@ -4042,10 +4041,8 @@ btr_cur_optimistic_update(
 			+ DTUPLE_EST_ALLOC(rec_offs_n_fields(*offsets)));
 	}
 
-	new_entry = row_rec_to_index_entry(rec, index, *offsets,
-					   &n_ext, *heap);
-	/* We checked above that there are no externally stored fields. */
-	ut_a(!n_ext);
+	new_entry = row_rec_to_index_entry(rec, index, *offsets, *heap);
+	ut_ad(!dtuple_get_n_ext(new_entry));
 
 	/* The page containing the clustered index record
 	corresponding to new_entry is latched in mtr.
@@ -4293,7 +4290,6 @@ btr_cur_pessimistic_update(
 	roll_ptr_t	roll_ptr;
 	ibool		was_first;
 	ulint		n_reserved	= 0;
-	ulint		n_ext;
 	ulint		max_ins_size	= 0;
 
 	*offsets = NULL;
@@ -4358,7 +4354,7 @@ btr_cur_pessimistic_update(
 	ut_ad(rec_offs_validate(rec, index, *offsets));
 
 	dtuple_t*	new_entry = row_rec_to_index_entry(
-		rec, index, *offsets, &n_ext, entry_heap);
+		rec, index, *offsets, entry_heap);
 
 	/* The page containing the clustered index record
 	corresponding to new_entry is latched in mtr.  If the
@@ -4375,9 +4371,6 @@ btr_cur_pessimistic_update(
 	ut_ad(!page_is_comp(page) || !rec_get_node_ptr_flag(rec));
 	ut_ad(rec_offs_validate(rec, index, *offsets));
 
-	/* Get number of externally stored columns in updated record */
-	n_ext = dtuple_get_n_ext(new_entry);
-
 	if ((flags & BTR_NO_UNDO_LOG_FLAG)
 	    && rec_offs_any_extern(*offsets)) {
 		/* We are in a transaction rollback undoing a row
@@ -4397,6 +4390,8 @@ btr_cur_pessimistic_update(
 			index, rec, page_zip, *offsets, update, true, mtr);
 	}
 
+	ulint n_ext = dtuple_get_n_ext(new_entry);
+
 	if (page_zip_rec_needs_ext(
 			rec_get_converted_size(index, new_entry, n_ext),
 			page_is_comp(page),

storage/innobase/include/row0row.h

 /*****************************************************************************
 
 Copyright (c) 1996, 2016, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2016, 2017, MariaDB Corporation.
+Copyright (c) 2016, 2020, 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
@@ -207,8 +207,6 @@ row_rec_to_index_entry_low(
 	const rec_t*		rec,	/*!< in: record in the index */
 	const dict_index_t*	index,	/*!< in: index */
 	const offset_t*		offsets,/*!< in: rec_get_offsets(rec, index) */
-	ulint*			n_ext,	/*!< out: number of externally
-					stored columns */
 	mem_heap_t*		heap)	/*!< in: memory heap from which
 					the memory needed is allocated */
 	MY_ATTRIBUTE((warn_unused_result));
@@ -222,8 +220,6 @@ row_rec_to_index_entry(
 	const rec_t*		rec,	/*!< in: record in the index */
 	const dict_index_t*	index,	/*!< in: index */
 	const offset_t*		offsets,/*!< in/out: rec_get_offsets(rec) */
-	ulint*			n_ext,	/*!< out: number of externally
-					stored columns */
 	mem_heap_t*		heap)	/*!< in: memory heap from which
 					the memory needed is allocated */
 	MY_ATTRIBUTE((warn_unused_result));

storage/innobase/row/row0ftsort.cc

 /*****************************************************************************
 
 Copyright (c) 2010, 2016, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2015, 2019, MariaDB Corporation.
+Copyright (c) 2015, 2020, 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
@@ -1720,7 +1720,6 @@ row_fts_merge_insert(
 	corresponding FTS index auxiliary tables */
 	for (;;) {
 		dtuple_t*	dtuple;
-		ulint		n_ext;
 		int		min_rec = 0;
 
 		if (fts_sort_pll_degree <= 2) {
@@ -1763,7 +1762,7 @@ row_fts_merge_insert(
 		}
 
 		dtuple = row_rec_to_index_entry_low(
-			mrec[min_rec], index, offsets[min_rec], &n_ext,
+			mrec[min_rec], index, offsets[min_rec],
 			tuple_heap);
 
 		row_fts_insert_tuple(

storage/innobase/row/row0log.cc

 /*****************************************************************************
 
 Copyright (c) 2011, 2018, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2017, 2019, MariaDB Corporation.
+Copyright (c) 2017, 2020, 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
@@ -3314,7 +3314,6 @@ row_log_apply_op(
 	enum row_op	op;
 	ulint		extra_size;
 	ulint		data_size;
-	ulint		n_ext;
 	dtuple_t*	entry;
 	trx_id_t	trx_id;
 
@@ -3392,10 +3391,10 @@ row_log_apply_op(
 	}
 
 	entry = row_rec_to_index_entry_low(
-		mrec - data_size, index, offsets, &n_ext, heap);
+		mrec - data_size, index, offsets, heap);
 	/* Online index creation is only implemented for secondary
 	indexes, which never contain off-page columns. */
-	ut_ad(n_ext == 0);
+	ut_ad(dtuple_get_n_ext(entry) == 0);
 
 	row_log_apply_op_low(index, dup, error, offsets_heap,
 			     has_index_lock, op, trx_id, entry);

storage/innobase/row/row0merge.cc

 /*****************************************************************************
 
 Copyright (c) 2005, 2017, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2014, 2019, MariaDB Corporation.
+Copyright (c) 2014, 2020, 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
@@ -3393,7 +3393,6 @@ row_merge_insert_index_tuples(
 	double			curr_progress = 0;
 	dict_index_t*		old_index = NULL;
 	const mrec_t*		mrec  = NULL;
-	ulint			n_ext = 0;
 	mtr_t			mtr;
 
 
@@ -3459,8 +3458,6 @@ row_merge_insert_index_tuples(
 			row buffer to data tuple record */
 			row_merge_mtuple_to_dtuple(
 				index, dtuple, &row_buf->tuples[n_rows]);
-
-			n_ext = dtuple_get_n_ext(dtuple);
 			n_rows++;
 			/* BLOB pointers must be copied from dtuple */
 			mrec = NULL;
@@ -3479,7 +3476,7 @@ row_merge_insert_index_tuples(
 			}
 
 			dtuple = row_rec_to_index_entry_low(
-				mrec, index, offsets, &n_ext, tuple_heap);
+				mrec, index, offsets, tuple_heap);
 		}
 
 		old_index	= dict_table_get_first_index(old_table);
@@ -3492,10 +3489,7 @@ row_merge_insert_index_tuples(
 			}
 		}
 
-		if (!n_ext) {
-			/* There are no externally stored columns. */
-		} else {
-			ut_ad(dict_index_is_clust(index));
+		if (dict_index_is_clust(index) && dtuple_get_n_ext(dtuple)) {
 			/* Off-page columns can be fetched safely
 			when concurrent modifications to the table
 			are disabled. (Purge can process delete-marked

storage/innobase/row/row0mysql.cc

@@ -4652,7 +4652,6 @@ row_scan_index_for_mysql(
 	ulint		i;
 	ulint		cnt;
 	mem_heap_t*	heap		= NULL;
-	ulint		n_ext;
 	offset_t	offsets_[REC_OFFS_NORMAL_SIZE];
 	offset_t*	offsets;
 	rec_offs_init(offsets_);
@@ -4793,7 +4792,7 @@ row_scan_index_for_mysql(
 		mem_heap_empty(heap);
 
 		prev_entry = row_rec_to_index_entry(
-			rec, index, offsets, &n_ext, heap);
+			rec, index, offsets, heap);
 
 		if (UNIV_LIKELY_NULL(tmp_heap)) {
 			mem_heap_free(tmp_heap);

storage/innobase/row/row0row.cc

 /*****************************************************************************
 
 Copyright (c) 1996, 2018, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2018, 2019, MariaDB Corporation.
+Copyright (c) 2018, 2020, 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
@@ -653,8 +653,6 @@ row_rec_to_index_entry_low(
 	const rec_t*		rec,	/*!< in: record in the index */
 	const dict_index_t*	index,	/*!< in: index */
 	const offset_t*		offsets,/*!< in: rec_get_offsets(rec, index) */
-	ulint*			n_ext,	/*!< out: number of externally
-					stored columns */
 	mem_heap_t*		heap)	/*!< in: memory heap from which
 					the memory needed is allocated */
 {
@@ -672,8 +670,6 @@ row_rec_to_index_entry_low(
 	/* Because this function may be invoked by row0merge.cc
 	on a record whose header is in different format, the check
 	rec_offs_validate(rec, index, offsets) must be avoided here. */
-	ut_ad(n_ext);
-	*n_ext = 0;
 
 	rec_len = rec_offs_n_fields(offsets);
 
@@ -698,7 +694,6 @@ row_rec_to_index_entry_low(
 
 		if (rec_offs_nth_extern(offsets, i)) {
 			dfield_set_ext(dfield);
-			(*n_ext)++;
 		}
 	}
 
@@ -717,8 +712,6 @@ row_rec_to_index_entry(
 	const rec_t*		rec,	/*!< in: record in the index */
 	const dict_index_t*	index,	/*!< in: index */
 	const offset_t*		offsets,/*!< in: rec_get_offsets(rec) */
-	ulint*			n_ext,	/*!< out: number of externally
-					stored columns */
 	mem_heap_t*		heap)	/*!< in: memory heap from which
 					the memory needed is allocated */
 {
@@ -739,7 +732,7 @@ row_rec_to_index_entry(
 
 	rec_offs_make_valid(copy_rec, index, const_cast<offset_t*>(offsets));
 	entry = row_rec_to_index_entry_low(
-		copy_rec, index, offsets, n_ext, heap);
+		copy_rec, index, offsets, heap);
 	rec_offs_make_valid(rec, index, const_cast<offset_t*>(offsets));
 
 	dtuple_set_info_bits(entry,

storage/innobase/row/row0upd.cc

 /*****************************************************************************
 
 Copyright (c) 1996, 2017, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2015, 2019, MariaDB Corporation.
+Copyright (c) 2015, 2020, 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
@@ -223,7 +223,6 @@ row_upd_check_references_constraints(
 	dtuple_t*	entry;
 	trx_t*		trx;
 	const rec_t*	rec;
-	ulint		n_ext;
 	dberr_t		err;
 	ibool		got_s_lock	= FALSE;
 
@@ -240,7 +239,7 @@ row_upd_check_references_constraints(
 
 	heap = mem_heap_create(500);
 
-	entry = row_rec_to_index_entry(rec, index, offsets, &n_ext, heap);
+	entry = row_rec_to_index_entry(rec, index, offsets, heap);
 
 	mtr_commit(mtr);
 
@@ -373,7 +372,6 @@ wsrep_row_upd_check_foreign_constraints(
 	dtuple_t*	entry;
 	trx_t*		trx;
 	const rec_t*	rec;
-	ulint		n_ext;
 	dberr_t		err;
 	ibool		got_s_lock	= FALSE;
 	ibool		opened     	= FALSE;
@@ -391,8 +389,7 @@ wsrep_row_upd_check_foreign_constraints(
 
 	heap = mem_heap_create(500);
 
-	entry = row_rec_to_index_entry(rec, index, offsets,
-				       &n_ext, heap);
+	entry = row_rec_to_index_entry(rec, index, offsets, heap);
 
 	mtr_commit(mtr);
 

storage/innobase/row/row0vers.cc

 /*****************************************************************************
 
 Copyright (c) 1997, 2017, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2017, 2019, MariaDB Corporation.
+Copyright (c) 2017, 2020, 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
@@ -136,15 +136,13 @@ row_vers_impl_x_locked_low(
 	const ulint rec_del = rec_get_deleted_flag(rec, comp);
 
 	if (dict_index_has_virtual(index)) {
-		ulint	n_ext;
 		ulint	est_size = DTUPLE_EST_ALLOC(index->n_fields);
 
 		/* Allocate the dtuple for virtual columns extracted from undo
 		log with its own heap, so to avoid it being freed as we
 		iterating in the version loop below. */
 		v_heap = mem_heap_create(est_size);
-		ientry = row_rec_to_index_entry(
-			rec, index, offsets, &n_ext, v_heap);
+		ientry = row_rec_to_index_entry(rec, index, offsets, v_heap);
 	}
 
 	/* We look up if some earlier version, which was modified by

storage/innobase/trx/trx0rec.cc

@@ -2404,8 +2404,6 @@ trx_undo_prev_version_build(
 	ut_a(ptr);
 
 	if (row_upd_changes_field_size_or_external(index, offsets, update)) {
-		ulint	n_ext;
-
 		/* We should confirm the existence of disowned external data,
 		if the previous version record is delete marked. If the trx_id
 		of the previous record is seen by purge view, we should treat
@@ -2446,15 +2444,14 @@ trx_undo_prev_version_build(
 		those fields that update updates to become externally stored
 		fields. Store the info: */
 
-		entry = row_rec_to_index_entry(
-			rec, index, offsets, &n_ext, heap);
+		entry = row_rec_to_index_entry(rec, index, offsets, heap);
 		/* The page containing the clustered index record
 		corresponding to entry is latched in mtr.  Thus the
 		following call is safe. */
 		row_upd_index_replace_new_col_vals(entry, index, update, heap);
 
 		/* Get number of externally stored columns in updated record */
-		n_ext = dtuple_get_n_ext(entry);
+		const ulint n_ext = dtuple_get_n_ext(entry);
 
 		buf = static_cast<byte*>(mem_heap_alloc(
 			heap, rec_get_converted_size(index, entry, n_ext)));