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>

common/eth2/src/lib.rs

@@ -21,7 +21,6 @@ use reqwest::{IntoUrl, Response};
 pub use reqwest::{StatusCode, Url};
 use sensitive_url::SensitiveUrl;
 use serde::{de::DeserializeOwned, Serialize};
-use ssz::Decode;
 use std::convert::TryFrom;
 use std::fmt;
 use std::iter::Iterator;
@@ -498,6 +497,7 @@ impl BeaconNodeHttpClient {
     pub async fn get_beacon_blocks_ssz<T: EthSpec>(
         &self,
         block_id: BlockId,
+        spec: &ChainSpec,
     ) -> Result<Option<SignedBeaconBlock<T>>, Error> {
         let mut path = self.eth_path()?;
 
@@ -509,7 +509,7 @@ impl BeaconNodeHttpClient {
 
         self.get_bytes_opt_accept_header(path, Accept::Ssz)
             .await?
-            .map(|bytes| SignedBeaconBlock::from_ssz_bytes(&bytes).map_err(Error::InvalidSsz))
+            .map(|bytes| SignedBeaconBlock::from_ssz_bytes(&bytes, spec).map_err(Error::InvalidSsz))
             .transpose()
     }
 
@@ -715,7 +715,7 @@ impl BeaconNodeHttpClient {
     }
 
     /// `GET config/spec`
-    pub async fn get_config_spec(&self) -> Result<GenericResponse<YamlConfig>, Error> {
+    pub async fn get_config_spec(&self) -> Result<GenericResponse<ConfigAndPreset>, Error> {
         let mut path = self.eth_path()?;
 
         path.path_segments_mut()
@@ -883,6 +883,7 @@ impl BeaconNodeHttpClient {
     pub async fn get_debug_beacon_states_ssz<T: EthSpec>(
         &self,
         state_id: StateId,
+        spec: &ChainSpec,
     ) -> Result<Option<BeaconState<T>>, Error> {
         let mut path = self.eth_path()?;
 
@@ -895,7 +896,7 @@ impl BeaconNodeHttpClient {
 
         self.get_bytes_opt_accept_header(path, Accept::Ssz)
             .await?
-            .map(|bytes| BeaconState::from_ssz_bytes(&bytes).map_err(Error::InvalidSsz))
+            .map(|bytes| BeaconState::from_ssz_bytes(&bytes, spec).map_err(Error::InvalidSsz))
             .transpose()
     }
 

common/eth2/src/lighthouse.rs

@@ -2,13 +2,12 @@
 
 use crate::{
     ok_or_error,
-    types::{BeaconState, Epoch, EthSpec, GenericResponse, ValidatorId},
+    types::{BeaconState, ChainSpec, Epoch, EthSpec, GenericResponse, ValidatorId},
     BeaconNodeHttpClient, DepositData, Error, Eth1Data, Hash256, StateId, StatusCode,
 };
 use proto_array::core::ProtoArray;
 use reqwest::IntoUrl;
 use serde::{Deserialize, Serialize};
-use ssz::Decode;
 use ssz_derive::{Decode, Encode};
 
 pub use eth2_libp2p::{types::SyncState, PeerInfo};
@@ -470,6 +469,7 @@ impl BeaconNodeHttpClient {
     pub async fn get_lighthouse_beacon_states_ssz<E: EthSpec>(
         &self,
         state_id: &StateId,
+        spec: &ChainSpec,
     ) -> Result<Option<BeaconState<E>>, Error> {
         let mut path = self.server.full.clone();
 
@@ -483,7 +483,7 @@ impl BeaconNodeHttpClient {
 
         self.get_bytes_opt(path)
             .await?
-            .map(|bytes| BeaconState::from_ssz_bytes(&bytes).map_err(Error::InvalidSsz))
+            .map(|bytes| BeaconState::from_ssz_bytes(&bytes, spec).map_err(Error::InvalidSsz))
             .transpose()
     }
 

common/eth2/src/lighthouse_vc/http_client.rs

@@ -211,7 +211,7 @@ impl ValidatorClientHttpClient {
     }
 
     /// `GET lighthouse/spec`
-    pub async fn get_lighthouse_spec(&self) -> Result<GenericResponse<YamlConfig>, Error> {
+    pub async fn get_lighthouse_spec(&self) -> Result<GenericResponse<ConfigAndPreset>, Error> {
         let mut path = self.server.full.clone();
 
         path.path_segments_mut()