Clone only needed KademliaPeers when yielding closest nodes (#326)

closes #53

---------

Co-authored-by: Dmitry Markin <dmitry@markin.tech>

Author: dharjeezy

src/protocol/libp2p/kademlia/bucket.rs

@@ -101,8 +101,8 @@ impl KBucket {
 
     /// Get iterator over the k-bucket, sorting the k-bucket entries in increasing order
     /// by distance.
-    pub fn closest_iter<K: Clone>(&self, target: &Key<K>) -> impl Iterator<Item = KademliaPeer> {
-        let mut nodes = self.nodes.clone();
+    pub fn closest_iter<K: Clone>(&self, target: &Key<K>) -> impl Iterator<Item = &KademliaPeer> {
+        let mut nodes: Vec<_> = self.nodes.iter().collect();
         nodes.sort_by(|a, b| target.distance(&a.key).cmp(&target.distance(&b.key)));
         nodes.into_iter().filter(|peer| !peer.addresses.is_empty())
     }

src/protocol/libp2p/kademlia/routing_table.rs

@@ -187,9 +187,10 @@ impl RoutingTable {
 
     /// Get `limit` closest peers to `target` from the k-buckets.
     pub fn closest<K: Clone>(&mut self, target: &Key<K>, limit: usize) -> Vec<KademliaPeer> {
-        ClosestBucketsIter::new(self.local_key.distance(target))
-            .flat_map(|index| self.buckets[index.get()].closest_iter(target))
+        ClosestBucketsIter::new(self.local_key.distance(&target))
+            .flat_map(|index| self.buckets[index.get()].closest_iter(&target))
             .take(limit)
+            .cloned()
             .collect()
     }
 }