Clean up obsolete TODOs (#1734)

Squashed commit of the following:

commit f99373cbae
Author: Age Manning <Age@AgeManning.com>
Date:   Mon Oct 5 18:44:09 2020 +1100

    Clean up obsolute TODOs

beacon_node/network/src/attestation_service/mod.rs

@@ -195,14 +195,9 @@ impl<T: BeaconChainTypes> AttestationService<T> {
                 slot: subscription.slot,
             };
 
-            // determine if the validator is an aggregator. If so, we subscribe to the subnet and
+            // Determine if the validator is an aggregator. If so, we subscribe to the subnet and
             // if successful add the validator to a mapping of known aggregators for that exact
             // subnet.
-            // NOTE: There is a chance that a fork occurs between now and when the validator needs
-            // to aggregate attestations. If this happens, the signature will no longer be valid
-            // and it could be likely the validator no longer needs to aggregate. More
-            // sophisticated logic should be added using known future forks.
-            // TODO: Implement
 
             if subscription.is_aggregator {
                 metrics::inc_counter(&metrics::SUBNET_SUBSCRIPTION_AGGREGATOR_REQUESTS);
@@ -286,8 +281,6 @@ impl<T: BeaconChainTypes> AttestationService<T> {
                         min_ttl,
                     })
                 } else {
-                    // TODO: Send the time frame needed to have a peer connected, so that we can
-                    // maintain peers for a least this duration.
                     // We may want to check the global PeerInfo to see estimated timeouts for each
                     // peer before they can be removed.
                     warn!(self.log,

beacon_node/network/src/service.rs

@@ -51,7 +51,7 @@ pub enum NetworkMessage<T: EthSpec> {
     },
     /// Respond to a peer's request with an error.
     SendError {
-        // TODO: note that this is never used, we just say goodbye without nicely closing the
+        // NOTE: Currently this is never used, we just say goodbye without nicely closing the
         // stream assigned to the request
         peer_id: PeerId,
         error: RPCResponseErrorCode,
@@ -163,7 +163,7 @@ impl<T: BeaconChainTypes> NetworkService<T> {
             "Loading peers into the routing table"; "peers" => enrs_to_load.len()
         );
         for enr in enrs_to_load {
-            libp2p.swarm.add_enr(enr.clone()); //TODO change?
+            libp2p.swarm.add_enr(enr.clone());
         }
 
         // launch derived network services
@@ -349,7 +349,6 @@ fn spawn_service<T: BeaconChainTypes>(
                 // process any attestation service events
                 Some(attestation_service_message) = service.attestation_service.next() => {
                     match attestation_service_message {
-                        // TODO: Implement
                         AttServiceMessage::Subscribe(subnet_id) => {
                             service.libp2p.swarm.subscribe_to_subnet(subnet_id);
                         }

beacon_node/network/src/sync/manager.rs

@@ -119,7 +119,6 @@ pub enum SyncMessage<T: EthSpec> {
 }
 
 /// The result of processing a multiple blocks (a chain segment).
-// TODO: When correct batch error handling occurs, we will include an error type.
 #[derive(Debug)]
 pub enum BatchProcessResult {
     /// The batch was completed successfully. It carries whether the sent batch contained blocks.
@@ -629,7 +628,7 @@ impl<T: BeaconChainTypes> SyncManager<T> {
         self.update_sync_state();
     }
 
-    // TODO: Group these functions into one.
+    // TODO: Group these functions into one for cleaner code.
     /// Updates the syncing state of a peer to be synced.
     fn synced_peer(&mut self, peer_id: &PeerId, sync_info: PeerSyncInfo) {
         if let Some(peer_info) = self.network_globals.peers.write().peer_info_mut(peer_id) {
@@ -792,7 +791,6 @@ impl<T: BeaconChainTypes> SyncManager<T> {
 
                     // This currently can be a host of errors. We permit this due to the partial
                     // ambiguity.
-                    // TODO: Refine the error types and score the peer appropriately.
                     self.network.report_peer(
                         parent_request.last_submitted_peer,
                         PeerAction::MidToleranceError,

beacon_node/network/src/sync/range_sync/chain.rs

@@ -613,9 +613,7 @@ impl<T: BeaconChainTypes> SyncingChain<T> {
                 BatchState::Failed | BatchState::Poisoned | BatchState::AwaitingDownload => {
                     unreachable!("batch indicates inconsistent chain state while advancing chain")
                 }
-                BatchState::AwaitingProcessing(..) => {
-                    // TODO: can we be sure the old attempts are wrong?
-                }
+                BatchState::AwaitingProcessing(..) => {}
                 BatchState::Processing(_) => {
                     assert_eq!(
                         id,
@@ -651,9 +649,6 @@ impl<T: BeaconChainTypes> SyncingChain<T> {
     /// These events occur when a peer has successfully responded with blocks, but the blocks we
     /// have received are incorrect or invalid. This indicates the peer has not performed as
     /// intended and can result in downvoting a peer.
-    // TODO: Batches could have been partially downloaded due to RPC size-limit restrictions. We
-    // need to add logic for partial batch downloads. Potentially, if another peer returns the same
-    // batch, we try a partial download.
     fn handle_invalid_batch(
         &mut self,
         network: &mut SyncNetworkContext<T::EthSpec>,

beacon_node/network/src/sync/range_sync/range.rs

@@ -220,7 +220,10 @@ impl<T: BeaconChainTypes> RangeSync<T> {
                     if let Some(removed_chain) = removed_chain {
                         debug!(self.log, "Chain removed after block response"; "sync_type" => ?sync_type, "chain_id" => chain_id);
                         removed_chain.status_peers(network);
-                        // TODO: update & update_sync_state?
+                        // update the state of the collection
+                        self.chains.update(network);
+                        // update the global state and inform the user
+                        self.chains.update_sync_state(network);
                     }
                 }
                 Err(_) => {
@@ -319,7 +322,10 @@ impl<T: BeaconChainTypes> RangeSync<T> {
             .call_all(|chain| chain.remove_peer(peer_id, network))
         {
             debug!(self.log, "Chain removed after removing peer"; "sync_type" => ?sync_type, "chain" => removed_chain.get_id());
-            // TODO: anything else to do?
+            // update the state of the collection
+            self.chains.update(network);
+            // update the global state and inform the user
+            self.chains.update_sync_state(network);
         }
     }
 
@@ -343,7 +349,10 @@ impl<T: BeaconChainTypes> RangeSync<T> {
                     if let Some(removed_chain) = removed_chain {
                         debug!(self.log, "Chain removed on rpc error"; "sync_type" => ?sync_type, "chain" => removed_chain.get_id());
                         removed_chain.status_peers(network);
-                        // TODO: update & update_sync_state?
+                        // update the state of the collection
+                        self.chains.update(network);
+                        // update the global state and inform the user
+                        self.chains.update_sync_state(network);
                     }
                 }
                 Err(_) => {