tuple: extract tuple_format_eq() from vy_stmt.c

Needed for #2754

src/box/tuple_format.c

@@ -211,6 +211,20 @@ tuple_format_new(struct tuple_format_vtab *vtab, struct key_def **keys,
 	return format;
 }
 
+bool
+tuple_format_eq(const struct tuple_format *a, const struct tuple_format *b)
+{
+	if (a->field_map_size != b->field_map_size ||
+	    a->field_count != b->field_count)
+		return false;
+	for (uint32_t i = 0; i < a->field_count; ++i) {
+		if (a->fields[i].type != b->fields[i].type ||
+		    a->fields[i].offset_slot != b->fields[i].offset_slot)
+			return false;
+	}
+	return true;
+}
+
 struct tuple_format *
 tuple_format_dup(const struct tuple_format *src)
 {

src/box/tuple_format.h

@@ -152,6 +152,14 @@ struct tuple_format *
 tuple_format_new(struct tuple_format_vtab *vtab, struct key_def **keys,
 		 uint16_t key_count, uint16_t extra_size);
 
+/**
+ * Check that two tuple formats are identical.
+ * @param a format a
+ * @param b format b
+ */
+bool
+tuple_format_eq(const struct tuple_format *a, const struct tuple_format *b);
+
 /**
  * Register the duplicate of the specified format.
  * @param src Original format.

src/box/vy_stmt.c

@@ -325,7 +325,6 @@ vy_stmt_replace_from_upsert(struct tuple_format *replace_format,
 
 	/* Copy statement data excluding UPSERT operations */
 	struct tuple_format *format = tuple_format_by_id(upsert->format_id);
-	(void)format;
 	/*
 	 * UPSERT must have the n_upserts field in the extra
 	 * memory.
@@ -335,10 +334,7 @@ vy_stmt_replace_from_upsert(struct tuple_format *replace_format,
 	 * In other fields the REPLACE tuple format must equal to
 	 * the UPSERT tuple format.
 	 */
-	assert(format->field_map_size == replace_format->field_map_size);
-	assert(format->field_count == replace_format->field_count);
-	assert(! memcmp(format->fields, replace_format->fields,
-			sizeof(struct tuple_field_format) * format->field_count));
+	assert(tuple_format_eq(format, replace_format));
 	struct tuple *replace = vy_stmt_alloc(replace_format, bsize);
 	if (replace == NULL)
 		return NULL;