Currently, the last statement returned by the write iterator is pinned
indirectly, via a read view. This works, because the write iterator can
only return a statement if it corresponds to a certain read view.
However, in the scope of #2129, the write iterator will also have to
keep statements for which a deferred DELETE hasn't been generated yet,
even if no read view needs it. So let's make the write iterator pin the
last returned statement explicitly, i.e. via a dedicated member of the
write_iterator struct.
Needed for #2129
---
src/box/vy_write_iterator.c | 20 +++++++++++++-------
1 file changed, 13 insertions(+), 7 deletions(-)
diff --git a/src/box/vy_write_iterator.c b/src/box/vy_write_iterator.c
index 4e758be8..06ae342b 100644
--- a/src/box/vy_write_iterator.c
+++ b/src/box/vy_write_iterator.c
@@ -192,6 +192,10 @@ struct vy_write_iterator {
*/
int stmt_i;
/**
+ * Last statement returned to the caller, pinned in memory.
+ */
+ struct tuple *last_stmt;
+ /**
* Read views of the same key sorted by LSN in descending
* order, starting from INT64_MAX.
*
@@ -398,6 +402,10 @@ vy_write_iterator_stop(struct vy_stmt_stream *vstream)
struct vy_write_src *src, *tmp;
rlist_foreach_entry_safe(src, &stream->src_list, in_src_list, tmp)
vy_write_iterator_delete_src(stream, src);
+ if (stream->last_stmt != NULL) {
+ vy_stmt_unref_if_possible(stream->last_stmt);
+ stream->last_stmt = NULL;
+ }
}
/**
@@ -527,12 +535,6 @@ static inline struct tuple *
vy_write_iterator_pop_read_view_stmt(struct vy_write_iterator *stream)
{
struct vy_read_view_stmt *rv;
- if (stream->stmt_i >= 0) {
- /* Destroy the current before getting to the next. */
- rv = &stream->read_views[stream->stmt_i];
- assert(rv->history == NULL);
- vy_read_view_stmt_destroy(rv);
- }
if (stream->rv_used_count == 0)
return NULL;
/* Find a next non-empty history element. */
@@ -544,7 +546,11 @@ vy_write_iterator_pop_read_view_stmt(struct
vy_write_iterator *stream)
} while (rv->tuple == NULL);
assert(stream->rv_used_count > 0);
stream->rv_used_count--;
- return rv->tuple;
+ if (stream->last_stmt != NULL)
+ vy_stmt_unref_if_possible(stream->last_stmt);
+ stream->last_stmt = rv->tuple;
+ rv->tuple = NULL;
+ return stream->last_stmt;
}
/**
--
2.11.0
