pub(super) fn set_preview_retention(desc: &mut Descriptor, configured: u64)Expand description
Raise the preview columns’ FIFO ttl to the configured preview lifetime when it exceeds their floor.
A preview evicted before it expires is fetched from the origin again, and
one whose lazy media mapping went with it serves an mxc:// URI that no
longer resolves, so the configured lifetime raises both columns. Only the
time arm moves: limit_size still caps each column, and evicts oldest
first once reached.