Use E for EthSpec globally (#5264)

* Use `E` for `EthSpec` globally

* Fix tests

* Merge branch 'unstable' into e-ethspec

* Merge branch 'unstable' into e-ethspec

# Conflicts:
#	beacon_node/execution_layer/src/engine_api.rs
#	beacon_node/execution_layer/src/engine_api/http.rs
#	beacon_node/execution_layer/src/engine_api/json_structures.rs
#	beacon_node/execution_layer/src/test_utils/handle_rpc.rs
#	beacon_node/store/src/partial_beacon_state.rs
#	consensus/types/src/beacon_block.rs
#	consensus/types/src/beacon_block_body.rs
#	consensus/types/src/beacon_state.rs
#	consensus/types/src/config_and_preset.rs
#	consensus/types/src/execution_payload.rs
#	consensus/types/src/execution_payload_header.rs
#	consensus/types/src/light_client_optimistic_update.rs
#	consensus/types/src/payload.rs
#	lcli/src/parse_ssz.rs

beacon_node/network/src/metrics.rs

@@ -337,9 +337,9 @@ pub fn register_sync_committee_error(error: &SyncCommitteeError) {
     inc_counter_vec(&GOSSIP_SYNC_COMMITTEE_ERRORS_PER_TYPE, &[error.as_ref()]);
 }
 
-pub fn update_gossip_metrics<T: EthSpec>(
+pub fn update_gossip_metrics<E: EthSpec>(
     gossipsub: &Gossipsub,
-    network_globals: &Arc<NetworkGlobals<T>>,
+    network_globals: &Arc<NetworkGlobals<E>>,
 ) {
     // Mesh peers per client
     // Reset the gauges
@@ -398,7 +398,7 @@ pub fn update_gossip_metrics<T: EthSpec>(
     }
 }
 
-pub fn update_sync_metrics<T: EthSpec>(network_globals: &Arc<NetworkGlobals<T>>) {
+pub fn update_sync_metrics<E: EthSpec>(network_globals: &Arc<NetworkGlobals<E>>) {
     // reset the counts
     if PEERS_PER_SYNC_TYPE
         .as_ref()

beacon_node/network/src/network_beacon_processor/gossip_methods.rs

@@ -78,8 +78,8 @@ impl<T: BeaconChainTypes> VerifiedAttestation<T> for VerifiedUnaggregate<T> {
 }
 
 /// An attestation that failed validation by the `BeaconChain`.
-struct RejectedUnaggregate<T: EthSpec> {
-    attestation: Box<Attestation<T>>,
+struct RejectedUnaggregate<E: EthSpec> {
+    attestation: Box<Attestation<E>>,
     error: AttnError,
 }
 
@@ -112,26 +112,26 @@ impl<T: BeaconChainTypes> VerifiedAttestation<T> for VerifiedAggregate<T> {
 }
 
 /// An attestation that failed validation by the `BeaconChain`.
-struct RejectedAggregate<T: EthSpec> {
-    signed_aggregate: Box<SignedAggregateAndProof<T>>,
+struct RejectedAggregate<E: EthSpec> {
+    signed_aggregate: Box<SignedAggregateAndProof<E>>,
     error: AttnError,
 }
 
 /// Data for an aggregated or unaggregated attestation that failed verification.
-enum FailedAtt<T: EthSpec> {
+enum FailedAtt<E: EthSpec> {
     Unaggregate {
-        attestation: Box<Attestation<T>>,
+        attestation: Box<Attestation<E>>,
         subnet_id: SubnetId,
         should_import: bool,
         seen_timestamp: Duration,
     },
     Aggregate {
-        attestation: Box<SignedAggregateAndProof<T>>,
+        attestation: Box<SignedAggregateAndProof<E>>,
         seen_timestamp: Duration,
     },
 }
 
-impl<T: EthSpec> FailedAtt<T> {
+impl<E: EthSpec> FailedAtt<E> {
     pub fn beacon_block_root(&self) -> &Hash256 {
         &self.attestation().data.beacon_block_root
     }
@@ -143,7 +143,7 @@ impl<T: EthSpec> FailedAtt<T> {
         }
     }
 
-    pub fn attestation(&self) -> &Attestation<T> {
+    pub fn attestation(&self) -> &Attestation<E> {
         match self {
             FailedAtt::Unaggregate { attestation, .. } => attestation,
             FailedAtt::Aggregate { attestation, .. } => &attestation.message.aggregate,

beacon_node/network/src/router.rs

@@ -49,7 +49,7 @@ pub struct Router<T: BeaconChainTypes> {
 
 /// Types of messages the router can receive.
 #[derive(Debug)]
-pub enum RouterMessage<T: EthSpec> {
+pub enum RouterMessage<E: EthSpec> {
     /// Peer has disconnected.
     PeerDisconnected(PeerId),
     /// An RPC request has been received.
@@ -62,7 +62,7 @@ pub enum RouterMessage<T: EthSpec> {
     RPCResponseReceived {
         peer_id: PeerId,
         request_id: RequestId,
-        response: Response<T>,
+        response: Response<E>,
     },
     /// An RPC request failed
     RPCFailed {
@@ -73,7 +73,7 @@ pub enum RouterMessage<T: EthSpec> {
     /// A gossip message has been received. The fields are: message id, the peer that sent us this
     /// message, the message itself and a bool which indicates if the message should be processed
     /// by the beacon chain after successful verification.
-    PubsubMessage(MessageId, PeerId, PubsubMessage<T>, bool),
+    PubsubMessage(MessageId, PeerId, PubsubMessage<E>, bool),
     /// The peer manager has requested we re-status a peer.
     StatusPeer(PeerId),
 }
@@ -645,20 +645,20 @@ impl<T: BeaconChainTypes> Router<T> {
 /// Wraps a Network Channel to employ various RPC related network functionality for the
 /// processor.
 #[derive(Clone)]
-pub struct HandlerNetworkContext<T: EthSpec> {
+pub struct HandlerNetworkContext<E: EthSpec> {
     /// The network channel to relay messages to the Network service.
-    network_send: mpsc::UnboundedSender<NetworkMessage<T>>,
+    network_send: mpsc::UnboundedSender<NetworkMessage<E>>,
     /// Logger for the `NetworkContext`.
     log: slog::Logger,
 }
 
-impl<T: EthSpec> HandlerNetworkContext<T> {
-    pub fn new(network_send: mpsc::UnboundedSender<NetworkMessage<T>>, log: slog::Logger) -> Self {
+impl<E: EthSpec> HandlerNetworkContext<E> {
+    pub fn new(network_send: mpsc::UnboundedSender<NetworkMessage<E>>, log: slog::Logger) -> Self {
         Self { network_send, log }
     }
 
     /// Sends a message to the network task.
-    fn inform_network(&mut self, msg: NetworkMessage<T>) {
+    fn inform_network(&mut self, msg: NetworkMessage<E>) {
         self.network_send.send(msg).unwrap_or_else(
             |e| warn!(self.log, "Could not send message to the network service"; "error" => %e),
         )
@@ -674,7 +674,7 @@ impl<T: EthSpec> HandlerNetworkContext<T> {
     }
 
     /// Sends a response to the network task.
-    pub fn send_response(&mut self, peer_id: PeerId, response: Response<T>, id: PeerRequestId) {
+    pub fn send_response(&mut self, peer_id: PeerId, response: Response<E>, id: PeerRequestId) {
         self.inform_network(NetworkMessage::SendResponse {
             peer_id,
             id,

beacon_node/network/src/service.rs

@@ -61,7 +61,7 @@ pub enum RequestId {
 /// Types of messages that the network service can receive.
 #[derive(Debug, IntoStaticStr)]
 #[strum(serialize_all = "snake_case")]
-pub enum NetworkMessage<T: EthSpec> {
+pub enum NetworkMessage<E: EthSpec> {
     /// Subscribes the beacon node to the core gossipsub topics. We do this when we are either
     /// synced or close to the head slot.
     SubscribeCoreTopics,
@@ -74,7 +74,7 @@ pub enum NetworkMessage<T: EthSpec> {
     /// Send a successful Response to the libp2p service.
     SendResponse {
         peer_id: PeerId,
-        response: Response<T>,
+        response: Response<E>,
         id: PeerRequestId,
     },
     /// Sends an error response to an RPC request.
@@ -85,7 +85,7 @@ pub enum NetworkMessage<T: EthSpec> {
         id: PeerRequestId,
     },
     /// Publish a list of messages to the gossipsub protocol.
-    Publish { messages: Vec<PubsubMessage<T>> },
+    Publish { messages: Vec<PubsubMessage<E>> },
     /// Validates a received gossipsub message. This will propagate the message on the network.
     ValidationResult {
         /// The peer that sent us the message. We don't send back to this peer.

beacon_node/network/src/sync/backfill_sync/mod.rs

@@ -55,7 +55,7 @@ impl BatchConfig for BackFillBatchConfig {
     fn max_batch_processing_attempts() -> u8 {
         MAX_BATCH_PROCESSING_ATTEMPTS
     }
-    fn batch_attempt_hash<T: EthSpec>(blocks: &[RpcBlock<T>]) -> u64 {
+    fn batch_attempt_hash<E: EthSpec>(blocks: &[RpcBlock<E>]) -> u64 {
         use std::collections::hash_map::DefaultHasher;
         use std::hash::{Hash, Hasher};
         let mut hasher = DefaultHasher::new();

beacon_node/network/src/sync/block_lookups/mod.rs

@@ -40,7 +40,7 @@ mod single_block_lookup;
 #[cfg(test)]
 mod tests;
 
-pub type DownloadedBlock<T> = (Hash256, RpcBlock<T>);
+pub type DownloadedBlock<E> = (Hash256, RpcBlock<E>);
 
 const FAILED_CHAINS_CACHE_EXPIRY_SECONDS: u64 = 60;
 pub const SINGLE_BLOCK_LOOKUP_MAX_ATTEMPTS: u8 = 3;

beacon_node/network/src/sync/block_lookups/single_block_lookup.rs

@@ -319,13 +319,13 @@ impl<L: Lookup, T: BeaconChainTypes> SingleBlockLookup<L, T> {
 }
 
 /// The state of the blob request component of a `SingleBlockLookup`.
-pub struct BlobRequestState<L: Lookup, T: EthSpec> {
+pub struct BlobRequestState<L: Lookup, E: EthSpec> {
     /// The latest picture of which blobs still need to be requested. This includes information
     /// from both block/blobs downloaded in the network layer and any blocks/blobs that exist in
     /// the data availability checker.
     pub requested_ids: MissingBlobs,
     /// Where we store blobs until we receive the stream terminator.
-    pub blob_download_queue: FixedBlobSidecarList<T>,
+    pub blob_download_queue: FixedBlobSidecarList<E>,
     pub state: SingleLookupRequestState,
     _phantom: PhantomData<L>,
 }

beacon_node/network/src/sync/block_sidecar_coupling.rs

@@ -4,33 +4,33 @@ use std::{collections::VecDeque, sync::Arc};
 use types::{BlobSidecar, EthSpec, SignedBeaconBlock};
 
 #[derive(Debug, Default)]
-pub struct BlocksAndBlobsRequestInfo<T: EthSpec> {
+pub struct BlocksAndBlobsRequestInfo<E: EthSpec> {
     /// Blocks we have received awaiting for their corresponding sidecar.
-    accumulated_blocks: VecDeque<Arc<SignedBeaconBlock<T>>>,
+    accumulated_blocks: VecDeque<Arc<SignedBeaconBlock<E>>>,
     /// Sidecars we have received awaiting for their corresponding block.
-    accumulated_sidecars: VecDeque<Arc<BlobSidecar<T>>>,
+    accumulated_sidecars: VecDeque<Arc<BlobSidecar<E>>>,
     /// Whether the individual RPC request for blocks is finished or not.
     is_blocks_stream_terminated: bool,
     /// Whether the individual RPC request for sidecars is finished or not.
     is_sidecars_stream_terminated: bool,
 }
 
-impl<T: EthSpec> BlocksAndBlobsRequestInfo<T> {
-    pub fn add_block_response(&mut self, block_opt: Option<Arc<SignedBeaconBlock<T>>>) {
+impl<E: EthSpec> BlocksAndBlobsRequestInfo<E> {
+    pub fn add_block_response(&mut self, block_opt: Option<Arc<SignedBeaconBlock<E>>>) {
         match block_opt {
             Some(block) => self.accumulated_blocks.push_back(block),
             None => self.is_blocks_stream_terminated = true,
         }
     }
 
-    pub fn add_sidecar_response(&mut self, sidecar_opt: Option<Arc<BlobSidecar<T>>>) {
+    pub fn add_sidecar_response(&mut self, sidecar_opt: Option<Arc<BlobSidecar<E>>>) {
         match sidecar_opt {
             Some(sidecar) => self.accumulated_sidecars.push_back(sidecar),
             None => self.is_sidecars_stream_terminated = true,
         }
     }
 
-    pub fn into_responses(self) -> Result<Vec<RpcBlock<T>>, String> {
+    pub fn into_responses(self) -> Result<Vec<RpcBlock<E>>, String> {
         let BlocksAndBlobsRequestInfo {
             accumulated_blocks,
             accumulated_sidecars,
@@ -42,7 +42,7 @@ impl<T: EthSpec> BlocksAndBlobsRequestInfo<T> {
         let mut responses = Vec::with_capacity(accumulated_blocks.len());
         let mut blob_iter = accumulated_sidecars.into_iter().peekable();
         for block in accumulated_blocks.into_iter() {
-            let mut blob_list = Vec::with_capacity(T::max_blobs_per_block());
+            let mut blob_list = Vec::with_capacity(E::max_blobs_per_block());
             while {
                 let pair_next_blob = blob_iter
                     .peek()
@@ -53,7 +53,7 @@ impl<T: EthSpec> BlocksAndBlobsRequestInfo<T> {
                 blob_list.push(blob_iter.next().ok_or("Missing next blob".to_string())?);
             }
 
-            let mut blobs_buffer = vec![None; T::max_blobs_per_block()];
+            let mut blobs_buffer = vec![None; E::max_blobs_per_block()];
             for blob in blob_list {
                 let blob_index = blob.index as usize;
                 let Some(blob_opt) = blobs_buffer.get_mut(blob_index) else {

beacon_node/network/src/sync/manager.rs

@@ -107,7 +107,7 @@ pub enum RequestId {
 
 #[derive(Debug)]
 /// A message that can be sent to the sync manager thread.
-pub enum SyncMessage<T: EthSpec> {
+pub enum SyncMessage<E: EthSpec> {
     /// A useful peer has been discovered.
     AddPeer(PeerId, SyncInfo),
 
@@ -115,7 +115,7 @@ pub enum SyncMessage<T: EthSpec> {
     RpcBlock {
         request_id: RequestId,
         peer_id: PeerId,
-        beacon_block: Option<Arc<SignedBeaconBlock<T>>>,
+        beacon_block: Option<Arc<SignedBeaconBlock<E>>>,
         seen_timestamp: Duration,
     },
 
@@ -123,15 +123,15 @@ pub enum SyncMessage<T: EthSpec> {
     RpcBlob {
         request_id: RequestId,
         peer_id: PeerId,
-        blob_sidecar: Option<Arc<BlobSidecar<T>>>,
+        blob_sidecar: Option<Arc<BlobSidecar<E>>>,
         seen_timestamp: Duration,
     },
 
     /// A block with an unknown parent has been received.
-    UnknownParentBlock(PeerId, RpcBlock<T>, Hash256),
+    UnknownParentBlock(PeerId, RpcBlock<E>, Hash256),
 
     /// A blob with an unknown parent has been received.
-    UnknownParentBlob(PeerId, Arc<BlobSidecar<T>>),
+    UnknownParentBlob(PeerId, Arc<BlobSidecar<E>>),
 
     /// A peer has sent an attestation that references a block that is unknown. This triggers the
     /// manager to attempt to find the block matching the unknown hash.
@@ -156,7 +156,7 @@ pub enum SyncMessage<T: EthSpec> {
     /// Block processed
     BlockComponentProcessed {
         process_type: BlockProcessType,
-        result: BlockProcessingResult<T>,
+        result: BlockProcessingResult<E>,
     },
 }
 
@@ -169,9 +169,9 @@ pub enum BlockProcessType {
 }
 
 #[derive(Debug)]
-pub enum BlockProcessingResult<T: EthSpec> {
+pub enum BlockProcessingResult<E: EthSpec> {
     Ok(AvailabilityProcessingStatus),
-    Err(BlockError<T>),
+    Err(BlockError<E>),
     Ignored,
 }
 
@@ -1077,10 +1077,10 @@ impl<T: BeaconChainTypes> SyncManager<T> {
     }
 }
 
-impl<T: EthSpec> From<Result<AvailabilityProcessingStatus, BlockError<T>>>
-    for BlockProcessingResult<T>
+impl<E: EthSpec> From<Result<AvailabilityProcessingStatus, BlockError<E>>>
+    for BlockProcessingResult<E>
 {
-    fn from(result: Result<AvailabilityProcessingStatus, BlockError<T>>) -> Self {
+    fn from(result: Result<AvailabilityProcessingStatus, BlockError<E>>) -> Self {
         match result {
             Ok(status) => BlockProcessingResult::Ok(status),
             Err(e) => BlockProcessingResult::Err(e),
@@ -1088,8 +1088,8 @@ impl<T: EthSpec> From<Result<AvailabilityProcessingStatus, BlockError<T>>>
     }
 }
 
-impl<T: EthSpec> From<BlockError<T>> for BlockProcessingResult<T> {
-    fn from(e: BlockError<T>) -> Self {
+impl<E: EthSpec> From<BlockError<E>> for BlockProcessingResult<E> {
+    fn from(e: BlockError<E>) -> Self {
         BlockProcessingResult::Err(e)
     }
 }

beacon_node/network/src/sync/network_context.rs

@@ -21,15 +21,15 @@ use std::sync::Arc;
 use tokio::sync::mpsc;
 use types::{BlobSidecar, EthSpec, SignedBeaconBlock};
 
-pub struct BlocksAndBlobsByRangeResponse<T: EthSpec> {
+pub struct BlocksAndBlobsByRangeResponse<E: EthSpec> {
     pub batch_id: BatchId,
-    pub responses: Result<Vec<RpcBlock<T>>, String>,
+    pub responses: Result<Vec<RpcBlock<E>>, String>,
 }
 
-pub struct BlocksAndBlobsByRangeRequest<T: EthSpec> {
+pub struct BlocksAndBlobsByRangeRequest<E: EthSpec> {
     pub chain_id: ChainId,
     pub batch_id: BatchId,
-    pub block_blob_info: BlocksAndBlobsRequestInfo<T>,
+    pub block_blob_info: BlocksAndBlobsRequestInfo<E>,
 }
 
 /// Wraps a Network channel to employ various RPC related network functionality for the Sync manager. This includes management of a global RPC request Id.
@@ -67,19 +67,19 @@ pub struct SyncNetworkContext<T: BeaconChainTypes> {
 }
 
 /// Small enumeration to make dealing with block and blob requests easier.
-pub enum BlockOrBlob<T: EthSpec> {
-    Block(Option<Arc<SignedBeaconBlock<T>>>),
-    Blob(Option<Arc<BlobSidecar<T>>>),
+pub enum BlockOrBlob<E: EthSpec> {
+    Block(Option<Arc<SignedBeaconBlock<E>>>),
+    Blob(Option<Arc<BlobSidecar<E>>>),
 }
 
-impl<T: EthSpec> From<Option<Arc<SignedBeaconBlock<T>>>> for BlockOrBlob<T> {
-    fn from(block: Option<Arc<SignedBeaconBlock<T>>>) -> Self {
+impl<E: EthSpec> From<Option<Arc<SignedBeaconBlock<E>>>> for BlockOrBlob<E> {
+    fn from(block: Option<Arc<SignedBeaconBlock<E>>>) -> Self {
         BlockOrBlob::Block(block)
     }
 }
 
-impl<T: EthSpec> From<Option<Arc<BlobSidecar<T>>>> for BlockOrBlob<T> {
-    fn from(blob: Option<Arc<BlobSidecar<T>>>) -> Self {
+impl<E: EthSpec> From<Option<Arc<BlobSidecar<E>>>> for BlockOrBlob<E> {
+    fn from(blob: Option<Arc<BlobSidecar<E>>>) -> Self {
         BlockOrBlob::Blob(blob)
     }
 }

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

@@ -56,7 +56,7 @@ pub trait BatchConfig {
     /// Note that simpler hashing functions considered in the past (hash of first block, hash of last
     /// block, number of received blocks) are not good enough to differentiate attempts. For this
     /// reason, we hash the complete set of blocks both in RangeSync and BackFillSync.
-    fn batch_attempt_hash<T: EthSpec>(blocks: &[RpcBlock<T>]) -> u64;
+    fn batch_attempt_hash<E: EthSpec>(blocks: &[RpcBlock<E>]) -> u64;
 }
 
 pub struct RangeSyncBatchConfig {}
@@ -68,7 +68,7 @@ impl BatchConfig for RangeSyncBatchConfig {
     fn max_batch_processing_attempts() -> u8 {
         MAX_BATCH_PROCESSING_ATTEMPTS
     }
-    fn batch_attempt_hash<T: EthSpec>(blocks: &[RpcBlock<T>]) -> u64 {
+    fn batch_attempt_hash<E: EthSpec>(blocks: &[RpcBlock<E>]) -> u64 {
         let mut hasher = std::collections::hash_map::DefaultHasher::new();
         blocks.hash(&mut hasher);
         hasher.finish()
@@ -92,7 +92,7 @@ pub enum BatchProcessingResult {
 }
 
 /// A segment of a chain.
-pub struct BatchInfo<T: EthSpec, B: BatchConfig = RangeSyncBatchConfig> {
+pub struct BatchInfo<E: EthSpec, B: BatchConfig = RangeSyncBatchConfig> {
     /// Start slot of the batch.
     start_slot: Slot,
     /// End slot of the batch.
@@ -104,7 +104,7 @@ pub struct BatchInfo<T: EthSpec, B: BatchConfig = RangeSyncBatchConfig> {
     /// The number of download retries this batch has undergone due to a failed request.
     failed_download_attempts: Vec<PeerId>,
     /// State of the batch.
-    state: BatchState<T>,
+    state: BatchState<E>,
     /// Whether this batch contains all blocks or all blocks and blobs.
     batch_type: ByRangeRequestType,
     /// Pin the generic
@@ -112,13 +112,13 @@ pub struct BatchInfo<T: EthSpec, B: BatchConfig = RangeSyncBatchConfig> {
 }
 
 /// Current state of a batch
-pub enum BatchState<T: EthSpec> {
+pub enum BatchState<E: EthSpec> {
     /// The batch has failed either downloading or processing, but can be requested again.
     AwaitingDownload,
     /// The batch is being downloaded.
-    Downloading(PeerId, Vec<RpcBlock<T>>, Id),
+    Downloading(PeerId, Vec<RpcBlock<E>>, Id),
     /// The batch has been completely downloaded and is ready for processing.
-    AwaitingProcessing(PeerId, Vec<RpcBlock<T>>),
+    AwaitingProcessing(PeerId, Vec<RpcBlock<E>>),
     /// The batch is being processed.
     Processing(Attempt),
     /// The batch was successfully processed and is waiting to be validated.
@@ -134,14 +134,14 @@ pub enum BatchState<T: EthSpec> {
     Failed,
 }
 
-impl<T: EthSpec> BatchState<T> {
+impl<E: EthSpec> BatchState<E> {
     /// Helper function for poisoning a state.
-    pub fn poison(&mut self) -> BatchState<T> {
+    pub fn poison(&mut self) -> BatchState<E> {
         std::mem::replace(self, BatchState::Poisoned)
     }
 }
 
-impl<T: EthSpec, B: BatchConfig> BatchInfo<T, B> {
+impl<E: EthSpec, B: BatchConfig> BatchInfo<E, B> {
     /// Batches are downloaded excluding the first block of the epoch assuming it has already been
     /// downloaded.
     ///
@@ -156,8 +156,8 @@ impl<T: EthSpec, B: BatchConfig> BatchInfo<T, B> {
     /// deal with this for now.
     /// This means finalization might be slower in deneb
     pub fn new(start_epoch: &Epoch, num_of_epochs: u64, batch_type: ByRangeRequestType) -> Self {
-        let start_slot = start_epoch.start_slot(T::slots_per_epoch());
-        let end_slot = start_slot + num_of_epochs * T::slots_per_epoch();
+        let start_slot = start_epoch.start_slot(E::slots_per_epoch());
+        let end_slot = start_slot + num_of_epochs * E::slots_per_epoch();
         BatchInfo {
             start_slot,
             end_slot,
@@ -242,7 +242,7 @@ impl<T: EthSpec, B: BatchConfig> BatchInfo<T, B> {
         }
     }
 
-    pub fn state(&self) -> &BatchState<T> {
+    pub fn state(&self) -> &BatchState<E> {
         &self.state
     }
 
@@ -251,7 +251,7 @@ impl<T: EthSpec, B: BatchConfig> BatchInfo<T, B> {
     }
 
     /// Adds a block to a downloading batch.
-    pub fn add_block(&mut self, block: RpcBlock<T>) -> Result<(), WrongState> {
+    pub fn add_block(&mut self, block: RpcBlock<E>) -> Result<(), WrongState> {
         match self.state.poison() {
             BatchState::Downloading(peer, mut blocks, req_id) => {
                 blocks.push(block);
@@ -383,10 +383,10 @@ impl<T: EthSpec, B: BatchConfig> BatchInfo<T, B> {
         }
     }
 
-    pub fn start_processing(&mut self) -> Result<Vec<RpcBlock<T>>, WrongState> {
+    pub fn start_processing(&mut self) -> Result<Vec<RpcBlock<E>>, WrongState> {
         match self.state.poison() {
             BatchState::AwaitingProcessing(peer, blocks) => {
-                self.state = BatchState::Processing(Attempt::new::<B, T>(peer, &blocks));
+                self.state = BatchState::Processing(Attempt::new::<B, E>(peer, &blocks));
                 Ok(blocks)
             }
             BatchState::Poisoned => unreachable!("Poisoned batch"),
@@ -481,13 +481,13 @@ pub struct Attempt {
 }
 
 impl Attempt {
-    fn new<B: BatchConfig, T: EthSpec>(peer_id: PeerId, blocks: &[RpcBlock<T>]) -> Self {
+    fn new<B: BatchConfig, E: EthSpec>(peer_id: PeerId, blocks: &[RpcBlock<E>]) -> Self {
         let hash = B::batch_attempt_hash(blocks);
         Attempt { peer_id, hash }
     }
 }
 
-impl<T: EthSpec, B: BatchConfig> slog::KV for &mut BatchInfo<T, B> {
+impl<E: EthSpec, B: BatchConfig> slog::KV for &mut BatchInfo<E, B> {
     fn serialize(
         &self,
         record: &slog::Record,
@@ -497,7 +497,7 @@ impl<T: EthSpec, B: BatchConfig> slog::KV for &mut BatchInfo<T, B> {
     }
 }
 
-impl<T: EthSpec, B: BatchConfig> slog::KV for BatchInfo<T, B> {
+impl<E: EthSpec, B: BatchConfig> slog::KV for BatchInfo<E, B> {
     fn serialize(
         &self,
         record: &slog::Record,
@@ -520,7 +520,7 @@ impl<T: EthSpec, B: BatchConfig> slog::KV for BatchInfo<T, B> {
     }
 }
 
-impl<T: EthSpec> std::fmt::Debug for BatchState<T> {
+impl<E: EthSpec> std::fmt::Debug for BatchState<E> {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {
             BatchState::Processing(Attempt {