putImmutableItem

Store an immutable item, the port of put_immutable_item. The key is DhtItem.target (= SHA-1 of the bencoded value). Re-putting the same target just refreshes its last-seen stamp. When the table is full a put of a new target is dropped (libtorrent instead evicts the least-important item; that popularity heuristic is a node-layer concern, so here a full table simply refuses new targets).

Parameters