Altair consensus changes and refactors (#2279)

## Proposed Changes

Implement the consensus changes necessary for the upcoming Altair hard fork.

## Additional Info

This is quite a heavy refactor, with pivotal types like the `BeaconState` and `BeaconBlock` changing from structs to enums. This ripples through the whole codebase with field accesses changing to methods, e.g. `state.slot` => `state.slot()`.


Co-authored-by: realbigsean <seananderson33@gmail.com>

beacon_node/eth2_libp2p/src/rpc/codec/ssz_snappy.rs

@@ -13,7 +13,7 @@ use std::io::ErrorKind;
 use std::io::{Read, Write};
 use std::marker::PhantomData;
 use tokio_util::codec::{Decoder, Encoder};
-use types::{EthSpec, SignedBeaconBlock};
+use types::{EthSpec, SignedBeaconBlock, SignedBeaconBlockBase};
 use unsigned_varint::codec::Uvi;
 
 /* Inbound Codec */
@@ -298,12 +298,18 @@ impl<TSpec: EthSpec> Decoder for SSZSnappyOutboundCodec<TSpec> {
                     Protocol::Goodbye => Err(RPCError::InvalidData),
                     Protocol::BlocksByRange => match self.protocol.version {
                         Version::V1 => Ok(Some(RPCResponse::BlocksByRange(Box::new(
-                            SignedBeaconBlock::from_ssz_bytes(&decoded_buffer)?,
+                            // FIXME(altair): support Altair blocks
+                            SignedBeaconBlock::Base(SignedBeaconBlockBase::from_ssz_bytes(
+                                &decoded_buffer,
+                            )?),
                         )))),
                     },
                     Protocol::BlocksByRoot => match self.protocol.version {
+                        // FIXME(altair): support Altair blocks
                         Version::V1 => Ok(Some(RPCResponse::BlocksByRoot(Box::new(
-                            SignedBeaconBlock::from_ssz_bytes(&decoded_buffer)?,
+                            SignedBeaconBlock::Base(SignedBeaconBlockBase::from_ssz_bytes(
+                                &decoded_buffer,
+                            )?),
                         )))),
                     },
                     Protocol::Ping => match self.protocol.version {

beacon_node/eth2_libp2p/src/rpc/methods.rs

@@ -354,10 +354,10 @@ impl<T: EthSpec> std::fmt::Display for RPCResponse<T> {
         match self {
             RPCResponse::Status(status) => write!(f, "{}", status),
             RPCResponse::BlocksByRange(block) => {
-                write!(f, "BlocksByRange: Block slot: {}", block.message.slot)
+                write!(f, "BlocksByRange: Block slot: {}", block.slot())
             }
             RPCResponse::BlocksByRoot(block) => {
-                write!(f, "BlocksByRoot: BLock slot: {}", block.message.slot)
+                write!(f, "BlocksByRoot: Block slot: {}", block.slot())
             }
             RPCResponse::Pong(ping) => write!(f, "Pong: {}", ping.data),
             RPCResponse::MetaData(metadata) => write!(f, "Metadata: {}", metadata.seq_number),

beacon_node/eth2_libp2p/src/rpc/protocol.rs

@@ -24,16 +24,16 @@ use types::{BeaconBlock, EthSpec, Hash256, MainnetEthSpec, Signature, SignedBeac
 lazy_static! {
     // Note: Hardcoding the `EthSpec` type for `SignedBeaconBlock` as min/max values is
     // same across different `EthSpec` implementations.
-    pub static ref SIGNED_BEACON_BLOCK_MIN: usize = SignedBeaconBlock::<MainnetEthSpec> {
-        message: BeaconBlock::empty(&MainnetEthSpec::default_spec()),
-        signature: Signature::empty(),
-    }
+    pub static ref SIGNED_BEACON_BLOCK_MIN: usize = SignedBeaconBlock::<MainnetEthSpec>::from_block(
+        BeaconBlock::empty(&MainnetEthSpec::default_spec()),
+        Signature::empty(),
+    )
     .as_ssz_bytes()
     .len();
-    pub static ref SIGNED_BEACON_BLOCK_MAX: usize = SignedBeaconBlock::<MainnetEthSpec> {
-        message: BeaconBlock::full(&MainnetEthSpec::default_spec()),
-        signature: Signature::empty(),
-    }
+    pub static ref SIGNED_BEACON_BLOCK_MAX: usize = SignedBeaconBlock::<MainnetEthSpec>::from_block(
+        BeaconBlock::full(&MainnetEthSpec::default_spec()),
+        Signature::empty(),
+    )
     .as_ssz_bytes()
     .len();
     pub static ref BLOCKS_BY_ROOT_REQUEST_MIN: usize =

beacon_node/eth2_libp2p/src/types/pubsub.rs

@@ -10,7 +10,7 @@ use std::io::{Error, ErrorKind};
 use types::SubnetId;
 use types::{
     Attestation, AttesterSlashing, EthSpec, ProposerSlashing, SignedAggregateAndProof,
-    SignedBeaconBlock, SignedVoluntaryExit,
+    SignedBeaconBlock, SignedBeaconBlockBase, SignedVoluntaryExit,
 };
 
 #[derive(Debug, Clone, PartialEq)]
@@ -141,8 +141,11 @@ impl<T: EthSpec> PubsubMessage<T> {
                         ))))
                     }
                     GossipKind::BeaconBlock => {
-                        let beacon_block = SignedBeaconBlock::from_ssz_bytes(data)
-                            .map_err(|e| format!("{:?}", e))?;
+                        // FIXME(altair): support Altair blocks
+                        let beacon_block = SignedBeaconBlock::Base(
+                            SignedBeaconBlockBase::from_ssz_bytes(data)
+                                .map_err(|e| format!("{:?}", e))?,
+                        );
                         Ok(PubsubMessage::BeaconBlock(Box::new(beacon_block)))
                     }
                     GossipKind::VoluntaryExit => {
@@ -189,7 +192,8 @@ impl<T: EthSpec> std::fmt::Display for PubsubMessage<T> {
             PubsubMessage::BeaconBlock(block) => write!(
                 f,
                 "Beacon Block: slot: {}, proposer_index: {}",
-                block.message.slot, block.message.proposer_index
+                block.slot(),
+                block.message().proposer_index()
             ),
             PubsubMessage::AggregateAndProofAttestation(att) => write!(
                 f,

beacon_node/eth2_libp2p/tests/rpc_tests.rs

@@ -140,10 +140,7 @@ fn test_blocks_by_range_chunked_rpc() {
         // BlocksByRange Response
         let spec = E::default_spec();
         let empty_block = BeaconBlock::empty(&spec);
-        let empty_signed = SignedBeaconBlock {
-            message: empty_block,
-            signature: Signature::empty(),
-        };
+        let empty_signed = SignedBeaconBlock::from_block(empty_block, Signature::empty());
         let rpc_response = Response::BlocksByRange(Some(Box::new(empty_signed)));
 
         // keep count of the number of messages received
@@ -257,10 +254,7 @@ fn test_blocks_by_range_chunked_rpc_terminates_correctly() {
         // BlocksByRange Response
         let spec = E::default_spec();
         let empty_block = BeaconBlock::empty(&spec);
-        let empty_signed = SignedBeaconBlock {
-            message: empty_block,
-            signature: Signature::empty(),
-        };
+        let empty_signed = SignedBeaconBlock::from_block(empty_block, Signature::empty());
         let rpc_response = Response::BlocksByRange(Some(Box::new(empty_signed)));
 
         // keep count of the number of messages received
@@ -390,10 +384,7 @@ fn test_blocks_by_range_single_empty_rpc() {
         // BlocksByRange Response
         let spec = E::default_spec();
         let empty_block = BeaconBlock::empty(&spec);
-        let empty_signed = SignedBeaconBlock {
-            message: empty_block,
-            signature: Signature::empty(),
-        };
+        let empty_signed = SignedBeaconBlock::from_block(empty_block, Signature::empty());
         let rpc_response = Response::BlocksByRange(Some(Box::new(empty_signed)));
 
         let messages_to_send = 1;
@@ -510,10 +501,7 @@ fn test_blocks_by_root_chunked_rpc() {
 
         // BlocksByRoot Response
         let full_block = BeaconBlock::full(&spec);
-        let signed_full_block = SignedBeaconBlock {
-            message: full_block,
-            signature: Signature::empty(),
-        };
+        let signed_full_block = SignedBeaconBlock::from_block(full_block, Signature::empty());
         let rpc_response = Response::BlocksByRoot(Some(Box::new(signed_full_block)));
 
         // keep count of the number of messages received
@@ -634,10 +622,7 @@ fn test_blocks_by_root_chunked_rpc_terminates_correctly() {
 
         // BlocksByRoot Response
         let full_block = BeaconBlock::full(&spec);
-        let signed_full_block = SignedBeaconBlock {
-            message: full_block,
-            signature: Signature::empty(),
-        };
+        let signed_full_block = SignedBeaconBlock::from_block(full_block, Signature::empty());
         let rpc_response = Response::BlocksByRoot(Some(Box::new(signed_full_block)));
 
         // keep count of the number of messages received