Resolve some PeerDAS todos (#6434)

* Resolve some PeerDAS todos

beacon_node/network/src/sync/manager.rs

@@ -1188,22 +1188,14 @@ impl<T: BeaconChainTypes> SyncManager<T> {
     }
 
     fn on_sampling_result(&mut self, requester: SamplingRequester, result: SamplingResult) {
-        // TODO(das): How is a consumer of sampling results?
-        // - Fork-choice for trailing DA
-        // - Single lookups to complete import requirements
-        // - Range sync to complete import requirements? Can sampling for syncing lag behind and
-        //   accumulate in fork-choice?
-
         match requester {
             SamplingRequester::ImportedBlock(block_root) => {
                 debug!(self.log, "Sampling result"; "block_root" => %block_root, "result" => ?result);
 
-                // TODO(das): Consider moving SamplingResult to the beacon_chain crate and import
-                // here. No need to add too much enum variants, just whatever the beacon_chain or
-                // fork-choice needs to make a decision. Currently the fork-choice only needs to
-                // be notified of successful samplings, i.e. sampling failures don't trigger pruning
                 match result {
                     Ok(_) => {
+                        // Notify the fork-choice of a successful sampling result to mark the block
+                        // branch as safe.
                         if let Err(e) = self
                             .network
                             .beacon_processor()

beacon_node/network/src/sync/network_context.rs

@@ -769,7 +769,6 @@ impl<T: BeaconChainTypes> SyncNetworkContext<T> {
             self.log.clone(),
         );
 
-        // TODO(das): start request
         // Note that you can only send, but not handle a response here
         match request.continue_requests(self) {
             Ok(_) => {
@@ -779,7 +778,6 @@ impl<T: BeaconChainTypes> SyncNetworkContext<T> {
                 self.custody_by_root_requests.insert(requester, request);
                 Ok(LookupRequestResult::RequestSent(req_id))
             }
-            // TODO(das): handle this error properly
             Err(e) => Err(RpcRequestSendError::CustodyRequestError(e)),
         }
     }

beacon_node/network/src/sync/peer_sampling.rs

@@ -24,7 +24,6 @@ pub type SamplingResult = Result<(), SamplingError>;
 type DataColumnSidecarList<E> = Vec<Arc<DataColumnSidecar<E>>>;
 
 pub struct Sampling<T: BeaconChainTypes> {
-    // TODO(das): stalled sampling request are never cleaned up
     requests: HashMap<SamplingRequester, ActiveSamplingRequest<T>>,
     sampling_config: SamplingConfig,
     log: slog::Logger,
@@ -313,8 +312,8 @@ impl<T: BeaconChainTypes> ActiveSamplingRequest<T> {
                         .iter()
                         .position(|data| &data.index == column_index)
                     else {
-                        // Peer does not have the requested data.
+                        // Peer does not have the requested data, mark peer as "dont have" and try
-                        // TODO(das) what to do?
+                        // again with a different peer.
                         debug!(self.log,
                             "Sampling peer claims to not have the data";
                             "block_root" => %self.block_root,
@@ -373,7 +372,9 @@ impl<T: BeaconChainTypes> ActiveSamplingRequest<T> {
                             sampling_request_id,
                         },
                     ) {
-                        // TODO(das): Beacon processor is overloaded, what should we do?
+                        // Beacon processor is overloaded, drop sampling attempt. Failing to sample
+                        // is not a permanent state so we should recover once the node has capacity
+                        // and receives a descendant block.
                         error!(self.log,
                             "Dropping sampling";
                             "block" => %self.block_root,
@@ -391,8 +392,8 @@ impl<T: BeaconChainTypes> ActiveSamplingRequest<T> {
                 );
                 metrics::inc_counter_vec(&metrics::SAMPLE_DOWNLOAD_RESULT, &[metrics::FAILURE]);
 
-                // Error downloading, maybe penalize peer and retry again.
+                // Error downloading, malicious network errors are already penalized before
-                // TODO(das) with different peer or different peer?
+                // reaching this function. Mark the peer as failed and try again with another.
                 for column_index in column_indexes {
                     let Some(request) = self.column_requests.get_mut(column_index) else {
                         warn!(self.log,
@@ -453,7 +454,7 @@ impl<T: BeaconChainTypes> ActiveSamplingRequest<T> {
                 debug!(self.log, "Sample verification failure"; "block_root" => %self.block_root, "column_indexes" => ?column_indexes, "reason" => ?err);
                 metrics::inc_counter_vec(&metrics::SAMPLE_VERIFY_RESULT, &[metrics::FAILURE]);
 
-                // TODO(das): Peer sent invalid data, penalize and try again from different peer
+                // Peer sent invalid data, penalize and try again from different peer
                 // TODO(das): Count individual failures
                 for column_index in column_indexes {
                     let Some(request) = self.column_requests.get_mut(column_index) else {