fix: comment on prove_block and only provide new blocks

Signed-off-by: ljedrz <ljedrz@gmail.com>

src/p2p/behaviour.rs

@@ -433,6 +433,9 @@ impl<Types: IpfsTypes> Behaviour<Types> {
     ) -> Result<SubscriptionFuture<(), String>, anyhow::Error> {
         let key = cid.to_bytes();
         match self.kademlia.start_providing(key.into()) {
+            // Kademlia queries are marked with QueryIds, which are most fitting to
+            // be used as kad Subscription keys - they are small and require no
+            // conversion for the applicable finish_subscription calls
             Ok(id) => Ok(self.kad_subscriptions.create_subscription(id.into(), None)),
             Err(e) => Err(anyhow!("kad: can't provide block {}: {:?}", cid, e)),
         }

src/repo/mod.rs

@@ -204,17 +204,20 @@ impl<TRepoTypes: RepoTypes> Repo<TRepoTypes> {
         let (_cid, res) = self.block_store.put(block.clone()).await?;
         self.subscriptions
             .finish_subscription(cid.clone().into(), Ok(block));
-        // sending only fails if no one is listening anymore
-        // and that is okay with us.
-        let (tx, rx) = oneshot::channel();
 
-        self.events
+        if let BlockPut::NewBlock = res {
-            .clone()
+            // sending only fails if no one is listening anymore
-            .send(RepoEvent::ProvideBlock(cid.clone(), tx))
+            // and that is okay with us.
-            .await
+            let (tx, rx) = oneshot::channel();
-            .ok();
 
-        rx.await??.await?;
+            self.events
+                .clone()
+                .send(RepoEvent::ProvideBlock(cid.clone(), tx))
+                .await
+                .ok();
+
+            rx.await??.await?;
+        }
 
         Ok((cid, res))
     }