Add Eth1Chain member to BeaconChain

beacon_node/beacon_chain/src/beacon_chain.rs

@@ -1,10 +1,10 @@
 use crate::checkpoint::CheckPoint;
 use crate::errors::{BeaconChainError as Error, BlockProductionError};
+use crate::eth1_chain::{Eth1Chain, Eth1ChainBackend};
 use crate::fork_choice::{Error as ForkChoiceError, ForkChoice};
 use crate::iter::{ReverseBlockRootIterator, ReverseStateRootIterator};
 use crate::metrics;
 use crate::persisted_beacon_chain::{PersistedBeaconChain, BEACON_CHAIN_DB_KEY};
-use eth2_hashing::hash;
 use lmd_ghost::LmdGhost;
 use operation_pool::DepositInsertStatus;
 use operation_pool::{OperationPool, PersistedOperationPool};
@@ -113,6 +113,7 @@ pub trait BeaconChainTypes: Send + Sync + 'static {
     type Store: store::Store;
     type SlotClock: slot_clock::SlotClock;
     type LmdGhost: LmdGhost<Self::Store, Self::EthSpec>;
+    type Eth1Chain: Eth1ChainBackend<Self::EthSpec>;
     type EthSpec: types::EthSpec;
 }
 
@@ -127,6 +128,8 @@ pub struct BeaconChain<T: BeaconChainTypes> {
     /// Stores all operations (e.g., `Attestation`, `Deposit`, etc) that are candidates for
     /// inclusion in a block.
     pub op_pool: OperationPool<T::EthSpec>,
+    /// Provides information from the Ethereum 1 (PoW) chain.
+    pub eth1_chain: Eth1Chain<T>,
     /// Stores a "snapshot" of the chain at the time the head-of-the-chain block was received.
     canonical_head: RwLock<CheckPoint<T::EthSpec>>,
     /// The root of the genesis block.
@@ -142,6 +145,7 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
     /// Instantiate a new Beacon Chain, from genesis.
     pub fn from_genesis(
         store: Arc<T::Store>,
+        eth1_backend: T::Eth1Chain,
         mut genesis_state: BeaconState<T::EthSpec>,
         mut genesis_block: BeaconBlock<T::EthSpec>,
         spec: ChainSpec,
@@ -186,6 +190,7 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
             spec,
             slot_clock,
             op_pool: OperationPool::new(),
+            eth1_chain: Eth1Chain::new(eth1_backend),
             canonical_head,
             genesis_block_root,
             fork_choice: ForkChoice::new(store.clone(), &genesis_block, genesis_block_root),
@@ -197,6 +202,7 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
     /// Attempt to load an existing instance from the given `store`.
     pub fn from_store(
         store: Arc<T::Store>,
+        eth1_backend: T::Eth1Chain,
         spec: ChainSpec,
         log: Logger,
     ) -> Result<Option<BeaconChain<T>>, Error> {
@@ -233,6 +239,7 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
             slot_clock,
             fork_choice: ForkChoice::new(store.clone(), last_finalized_block, last_finalized_root),
             op_pool,
+            eth1_chain: Eth1Chain::new(eth1_backend),
             canonical_head: RwLock::new(p.canonical_head),
             genesis_block_root: p.genesis_block_root,
             store,
@@ -1205,12 +1212,12 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
             body: BeaconBlockBody {
                 randao_reveal,
                 // TODO: replace with real data.
-                eth1_data: Self::eth1_data_stub(&state),
+                eth1_data: self.eth1_chain.eth1_data_for_block_production(&state)?,
                 graffiti,
                 proposer_slashings: proposer_slashings.into(),
                 attester_slashings: attester_slashings.into(),
                 attestations: self.op_pool.get_attestations(&state, &self.spec).into(),
-                deposits: self.op_pool.get_deposits(&state).into(),
+                deposits: self.eth1_chain.deposits_for_block_inclusion(&state)?.into(),
                 voluntary_exits: self.op_pool.get_voluntary_exits(&state, &self.spec).into(),
                 transfers: self.op_pool.get_transfers(&state, &self.spec).into(),
             },
@@ -1234,22 +1241,6 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
         Ok((block, state))
     }
 
-    fn eth1_data_stub(state: &BeaconState<T::EthSpec>) -> Eth1Data {
-        let current_epoch = state.current_epoch();
-        let slots_per_voting_period = T::EthSpec::slots_per_eth1_voting_period() as u64;
-        let current_voting_period: u64 = current_epoch.as_u64() / slots_per_voting_period;
-
-        // TODO: confirm that `int_to_bytes32` is correct.
-        let deposit_root = hash(&int_to_bytes32(current_voting_period));
-        let block_hash = hash(&deposit_root);
-
-        Eth1Data {
-            deposit_root: Hash256::from_slice(&deposit_root),
-            deposit_count: state.eth1_deposit_index,
-            block_hash: Hash256::from_slice(&block_hash),
-        }
-    }
-
     /// Execute the fork choice algorithm and enthrone the result as the canonical head.
     pub fn fork_choice(&self) -> Result<(), Error> {
         metrics::inc_counter(&metrics::FORK_CHOICE_REQUESTS);
@@ -1445,13 +1436,6 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
     }
 }
 
-/// Returns `int` as little-endian bytes with a length of 32.
-fn int_to_bytes32(int: u64) -> Vec<u8> {
-    let mut vec = int.to_le_bytes().to_vec();
-    vec.resize(32, 0);
-    vec
-}
-
 impl From<DBError> for Error {
     fn from(e: DBError) -> Error {
         Error::DBError(e)

beacon_node/beacon_chain/src/beacon_chain_builder.rs

@@ -127,16 +127,23 @@ impl<T: BeaconChainTypes> BeaconChainBuilder<T> {
         }
     }
 
-    pub fn build(self, store: Arc<T::Store>) -> Result<BeaconChain<T>, String> {
+    pub fn build(
+        self,
+        store: Arc<T::Store>,
+        eth1_backend: T::Eth1Chain,
+    ) -> Result<BeaconChain<T>, String> {
         Ok(match self.build_strategy {
-            BuildStrategy::LoadFromStore => BeaconChain::from_store(store, self.spec, self.log)
+            BuildStrategy::LoadFromStore => {
-                .map_err(|e| format!("Error loading BeaconChain from database: {:?}", e))?
+                BeaconChain::from_store(store, eth1_backend, self.spec, self.log)
-                .ok_or_else(|| format!("Unable to find exising BeaconChain in database."))?,
+                    .map_err(|e| format!("Error loading BeaconChain from database: {:?}", e))?
+                    .ok_or_else(|| format!("Unable to find exising BeaconChain in database."))?
+            }
             BuildStrategy::FromGenesis {
                 genesis_block,
                 genesis_state,
             } => BeaconChain::from_genesis(
                 store,
+                eth1_backend,
                 genesis_state.as_ref().clone(),
                 genesis_block.as_ref().clone(),
                 self.spec,

beacon_node/beacon_chain/src/errors.rs

@@ -1,3 +1,4 @@
+use crate::eth1_chain::Error as Eth1ChainError;
 use crate::fork_choice::Error as ForkChoiceError;
 use state_processing::per_block_processing::errors::AttestationValidationError;
 use state_processing::BlockProcessingError;
@@ -42,6 +43,7 @@ pub enum BeaconChainError {
 }
 
 easy_from_to!(SlotProcessingError, BeaconChainError);
+easy_from_to!(AttestationValidationError, BeaconChainError);
 
 #[derive(Debug, PartialEq)]
 pub enum BlockProductionError {
@@ -50,10 +52,11 @@ pub enum BlockProductionError {
     UnableToProduceAtSlot(Slot),
     SlotProcessingError(SlotProcessingError),
     BlockProcessingError(BlockProcessingError),
+    Eth1ChainError(Eth1ChainError),
     BeaconStateError(BeaconStateError),
 }
 
 easy_from_to!(BlockProcessingError, BlockProductionError);
 easy_from_to!(BeaconStateError, BlockProductionError);
 easy_from_to!(SlotProcessingError, BlockProductionError);
-easy_from_to!(AttestationValidationError, BeaconChainError);
+easy_from_to!(Eth1ChainError, BlockProductionError);

beacon_node/beacon_chain/src/eth1_chain.rs

@@ -5,6 +5,35 @@ use types::{BeaconState, Deposit, DepositData, Eth1Data, EthSpec, Hash256};
 
 type Result<T> = std::result::Result<T, Error>;
 
+pub struct Eth1Chain<T: BeaconChainTypes> {
+    backend: T::Eth1Chain,
+}
+
+impl<T: BeaconChainTypes> Eth1Chain<T> {
+    pub fn new(backend: T::Eth1Chain) -> Self {
+        Self { backend }
+    }
+
+    pub fn eth1_data_for_block_production(
+        &self,
+        state: &BeaconState<T::EthSpec>,
+    ) -> Result<Eth1Data> {
+        self.backend.eth1_data(state)
+    }
+
+    pub fn deposits_for_block_inclusion(
+        &self,
+        state: &BeaconState<T::EthSpec>,
+    ) -> Result<Vec<Deposit>> {
+        let deposits = self.backend.queued_deposits(state)?;
+
+        // TODO: truncate deposits if required.
+
+        Ok(deposits)
+    }
+}
+
+#[derive(Debug, PartialEq)]
 pub enum Error {
     /// Unable to return an Eth1Data for the given epoch.
     EpochUnavailable,
@@ -12,10 +41,10 @@ pub enum Error {
     BackendError(String),
 }
 
-pub trait Eth1Chain<T: BeaconChainTypes> {
+pub trait Eth1ChainBackend<T: EthSpec> {
     /// Returns the `Eth1Data` that should be included in a block being produced for the given
     /// `state`.
-    fn eth1_data_for_epoch(&self, beacon_state: &BeaconState<T::EthSpec>) -> Result<Eth1Data>;
+    fn eth1_data(&self, beacon_state: &BeaconState<T>) -> Result<Eth1Data>;
 
     /// Returns all `Deposits` between `state.eth1_deposit_index` and
     /// `state.eth1_data.deposit_count`.
@@ -24,20 +53,19 @@ pub trait Eth1Chain<T: BeaconChainTypes> {
     ///
     /// It is possible that not all returned `Deposits` can be included in a block. E.g., there may
     /// be more than `MAX_DEPOSIT_COUNT` or the churn may be too high.
-    fn queued_deposits(&self, beacon_state: &BeaconState<T::EthSpec>) -> Result<Vec<Deposit>>;
+    fn queued_deposits(&self, beacon_state: &BeaconState<T>) -> Result<Vec<Deposit>>;
 }
 
-pub struct InteropEth1Chain<T: BeaconChainTypes> {
+pub struct InteropEth1ChainBackend<T: EthSpec> {
     _phantom: PhantomData<T>,
 }
 
-impl<T: BeaconChainTypes> Eth1Chain<T> for InteropEth1Chain<T> {
+impl<T: EthSpec> Eth1ChainBackend<T> for InteropEth1ChainBackend<T> {
-    fn eth1_data_for_epoch(&self, state: &BeaconState<T::EthSpec>) -> Result<Eth1Data> {
+    fn eth1_data(&self, state: &BeaconState<T>) -> Result<Eth1Data> {
         let current_epoch = state.current_epoch();
-        let slots_per_voting_period = T::EthSpec::slots_per_eth1_voting_period() as u64;
+        let slots_per_voting_period = T::slots_per_eth1_voting_period() as u64;
         let current_voting_period: u64 = current_epoch.as_u64() / slots_per_voting_period;
 
-        // TODO: confirm that `int_to_bytes32` is correct.
         let deposit_root = hash(&int_to_bytes32(current_voting_period));
         let block_hash = hash(&deposit_root);
 
@@ -48,11 +76,19 @@ impl<T: BeaconChainTypes> Eth1Chain<T> for InteropEth1Chain<T> {
         })
     }
 
-    fn queued_deposits(&self, beacon_state: &BeaconState<T::EthSpec>) -> Result<Vec<Deposit>> {
+    fn queued_deposits(&self, beacon_state: &BeaconState<T>) -> Result<Vec<Deposit>> {
         Ok(vec![])
     }
 }
 
+impl<T: EthSpec> Default for InteropEth1ChainBackend<T> {
+    fn default() -> Self {
+        Self {
+            _phantom: PhantomData,
+        }
+    }
+}
+
 /// Returns `int` as little-endian bytes with a length of 32.
 fn int_to_bytes32(int: u64) -> Vec<u8> {
     let mut vec = int.to_le_bytes().to_vec();

beacon_node/beacon_chain/src/lib.rs

@@ -19,6 +19,7 @@ pub use self::beacon_chain::{
 pub use self::checkpoint::CheckPoint;
 pub use self::errors::{BeaconChainError, BlockProductionError};
 pub use beacon_chain_builder::BeaconChainBuilder;
+pub use eth1_chain::InteropEth1ChainBackend;
 pub use lmd_ghost;
 pub use metrics::scrape_for_metrics;
 pub use parking_lot;

beacon_node/beacon_chain/src/test_utils.rs

@@ -1,4 +1,4 @@
-use crate::{BeaconChain, BeaconChainTypes, BlockProcessingOutcome};
+use crate::{BeaconChain, BeaconChainTypes, BlockProcessingOutcome, InteropEth1ChainBackend};
 use lmd_ghost::LmdGhost;
 use rayon::prelude::*;
 use sloggers::{null::NullLoggerBuilder, Build};
@@ -60,6 +60,7 @@ where
     type Store = MemoryStore;
     type SlotClock = TestingSlotClock;
     type LmdGhost = L;
+    type Eth1Chain = InteropEth1ChainBackend<E>;
     type EthSpec = E;
 }
 
@@ -114,9 +115,15 @@ where
         let builder = NullLoggerBuilder;
         let log = builder.build().expect("logger should build");
 
-        let chain =
+        let chain = BeaconChain::from_genesis(
-            BeaconChain::from_genesis(store, genesis_state, genesis_block, spec.clone(), log)
+            store,
-                .expect("Terminate if beacon chain generation fails");
+            InteropEth1ChainBackend::default(),
+            genesis_state,
+            genesis_block,
+            spec.clone(),
+            log,
+        )
+        .expect("Terminate if beacon chain generation fails");
 
         Self {
             chain,