Merge pull request #308 from sigp/v0.5.0

Update to spec v0.5.0

Cargo.toml

@@ -11,6 +11,7 @@ members = [
 	"eth2/utils/honey-badger-split",
 	"eth2/utils/merkle_proof",
 	"eth2/utils/int_to_bytes",
+	"eth2/utils/serde_hex",
 	"eth2/utils/slot_clock",
 	"eth2/utils/ssz",
 	"eth2/utils/ssz_derive",

beacon_node/Cargo.toml

@@ -19,6 +19,7 @@ slog = "^2.2.3"
 slot_clock = { path = "../eth2/utils/slot_clock" }
 slog-term = "^2.4.0"
 slog-async = "^2.3.0"
+state_processing = { path = "../eth2/state_processing" }
 types = { path = "../eth2/types" }
 ssz = { path = "../eth2/utils/ssz" }
 tokio = "0.1"

beacon_node/beacon_chain/src/attestation_aggregator.rs

@@ -1,4 +1,3 @@
-use log::trace;
 use ssz::TreeHash;
 use state_processing::per_block_processing::validate_attestation_without_signature;
 use std::collections::{HashMap, HashSet};
@@ -86,10 +85,8 @@ impl AttestationAggregator {
         free_attestation: &FreeAttestation,
         spec: &ChainSpec,
     ) -> Result<Outcome, BeaconStateError> {
-        let attestation_duties = match state.attestation_slot_and_shard_for_validator(
+        let duties =
-            free_attestation.validator_index as usize,
+            match state.get_attestation_duties(free_attestation.validator_index as usize, spec) {
-            spec,
-        ) {
                 Err(BeaconStateError::EpochCacheUninitialized(e)) => {
                     panic!("Attempted to access unbuilt cache {:?}.", e)
                 }
@@ -100,20 +97,10 @@ impl AttestationAggregator {
                 Ok(Some(attestation_duties)) => attestation_duties,
             };
 
-        let (slot, shard, committee_index) = attestation_duties;
+        if free_attestation.data.slot != duties.slot {
-
-        trace!(
-            "slot: {}, shard: {}, committee_index: {}, val_index: {}",
-            slot,
-            shard,
-            committee_index,
-            free_attestation.validator_index
-        );
-
-        if free_attestation.data.slot != slot {
             invalid_outcome!(Message::BadSlot);
         }
-        if free_attestation.data.shard != shard {
+        if free_attestation.data.shard != duties.shard {
             invalid_outcome!(Message::BadShard);
         }
 
@@ -143,7 +130,7 @@ impl AttestationAggregator {
             if let Some(updated_attestation) = aggregate_attestation(
                 existing_attestation,
                 &free_attestation.signature,
-                committee_index as usize,
+                duties.committee_index as usize,
             ) {
                 self.store.insert(signable_message, updated_attestation);
                 valid_outcome!(Message::Aggregated);
@@ -154,7 +141,7 @@ impl AttestationAggregator {
             let mut aggregate_signature = AggregateSignature::new();
             aggregate_signature.add(&free_attestation.signature);
             let mut aggregation_bitfield = Bitfield::new();
-            aggregation_bitfield.set(committee_index as usize, true);
+            aggregation_bitfield.set(duties.committee_index as usize, true);
             let new_attestation = Attestation {
                 data: free_attestation.data.clone(),
                 aggregation_bitfield,
@@ -177,7 +164,11 @@ impl AttestationAggregator {
     ) -> Vec<Attestation> {
         let mut known_attestation_data: HashSet<AttestationData> = HashSet::new();
 
-        state.latest_attestations.iter().for_each(|attestation| {
+        state
+            .previous_epoch_attestations
+            .iter()
+            .chain(state.current_epoch_attestations.iter())
+            .for_each(|attestation| {
                 known_attestation_data.insert(attestation.data.clone());
             });
 

beacon_node/beacon_chain/src/beacon_chain.rs

@@ -15,10 +15,7 @@ use state_processing::{
     per_slot_processing, BlockProcessingError, SlotProcessingError,
 };
 use std::sync::Arc;
-use types::{
+use types::*;
-    readers::{BeaconBlockReader, BeaconStateReader},
-    *,
-};
 
 #[derive(Debug, PartialEq)]
 pub enum ValidBlock {
@@ -85,20 +82,18 @@ where
         let state_root = genesis_state.canonical_root();
         state_store.put(&state_root, &ssz_encode(&genesis_state)[..])?;
 
-        let block_root = genesis_block.canonical_root();
+        let block_root = genesis_block.block_header().canonical_root();
         block_store.put(&block_root, &ssz_encode(&genesis_block)[..])?;
 
         let finalized_head = RwLock::new(CheckPoint::new(
             genesis_block.clone(),
             block_root,
-            // TODO: this is a memory waste; remove full clone.
             genesis_state.clone(),
             state_root,
         ));
         let canonical_head = RwLock::new(CheckPoint::new(
             genesis_block.clone(),
             block_root,
-            // TODO: this is a memory waste; remove full clone.
             genesis_state.clone(),
             state_root,
         ));
@@ -106,7 +101,8 @@ where
 
         genesis_state.build_epoch_cache(RelativeEpoch::Previous, &spec)?;
         genesis_state.build_epoch_cache(RelativeEpoch::Current, &spec)?;
-        genesis_state.build_epoch_cache(RelativeEpoch::Next, &spec)?;
+        genesis_state.build_epoch_cache(RelativeEpoch::NextWithoutRegistryChange, &spec)?;
+        genesis_state.build_epoch_cache(RelativeEpoch::NextWithRegistryChange, &spec)?;
 
         Ok(Self {
             block_store,
@@ -192,10 +188,13 @@ where
     /// processing applied to it.
     pub fn advance_state(&self, slot: Slot) -> Result<(), SlotProcessingError> {
         let state_slot = self.state.read().slot;
-        let head_block_root = self.head().beacon_block_root;
+
+        let latest_block_header = self.head().beacon_block.block_header();
+
         for _ in state_slot.as_u64()..slot.as_u64() {
-            per_slot_processing(&mut *self.state.write(), head_block_root, &self.spec)?;
+            per_slot_processing(&mut *self.state.write(), &latest_block_header, &self.spec)?;
         }
+
         Ok(())
     }
 
@@ -248,19 +247,15 @@ where
     /// present and prior epoch is available.
     pub fn block_proposer(&self, slot: Slot) -> Result<usize, BeaconStateError> {
         trace!("BeaconChain::block_proposer: slot: {}", slot);
-        let index = self
+        let index = self.state.read().get_beacon_proposer_index(
-            .state
+            slot,
-            .read()
+            RelativeEpoch::Current,
-            .get_beacon_proposer_index(slot, &self.spec)?;
+            &self.spec,
+        )?;
 
         Ok(index)
     }
 
-    /// Returns the justified slot for the present state.
-    pub fn justified_epoch(&self) -> Epoch {
-        self.state.read().justified_epoch
-    }
-
     /// Returns the attestation slot and shard for a given validator index.
     ///
     /// Information is read from the current state, so only information from the present and prior
@@ -273,12 +268,12 @@ where
             "BeaconChain::validator_attestion_slot_and_shard: validator_index: {}",
             validator_index
         );
-        if let Some((slot, shard, _committee)) = self
+        if let Some(attestation_duty) = self
             .state
             .read()
-            .attestation_slot_and_shard_for_validator(validator_index, &self.spec)?
+            .get_attestation_duties(validator_index, &self.spec)?
         {
-            Ok(Some((slot, shard)))
+            Ok(Some((attestation_duty.slot, attestation_duty.shard)))
         } else {
             Ok(None)
         }
@@ -287,37 +282,33 @@ where
     /// Produce an `AttestationData` that is valid for the present `slot` and given `shard`.
     pub fn produce_attestation_data(&self, shard: u64) -> Result<AttestationData, Error> {
         trace!("BeaconChain::produce_attestation_data: shard: {}", shard);
-        let justified_epoch = self.justified_epoch();
+        let source_epoch = self.state.read().current_justified_epoch;
-        let justified_block_root = *self
+        let source_root = *self.state.read().get_block_root(
-            .state
+            source_epoch.start_slot(self.spec.slots_per_epoch),
-            .read()
-            .get_block_root(
-                justified_epoch.start_slot(self.spec.slots_per_epoch),
             &self.spec,
-            )
+        )?;
-            .ok_or_else(|| Error::BadRecentBlockRoots)?;
 
-        let epoch_boundary_root = *self
+        let target_root = *self.state.read().get_block_root(
-            .state
+            self.state
                 .read()
-            .get_block_root(
+                .slot
-                self.state.read().current_epoch_start_slot(&self.spec),
+                .epoch(self.spec.slots_per_epoch)
+                .start_slot(self.spec.slots_per_epoch),
             &self.spec,
-            )
+        )?;
-            .ok_or_else(|| Error::BadRecentBlockRoots)?;
 
         Ok(AttestationData {
             slot: self.state.read().slot,
             shard,
             beacon_block_root: self.head().beacon_block_root,
-            epoch_boundary_root,
+            target_root,
             crosslink_data_root: Hash256::zero(),
-            latest_crosslink: Crosslink {
+            previous_crosslink: Crosslink {
                 epoch: self.state.read().slot.epoch(self.spec.slots_per_epoch),
                 crosslink_data_root: Hash256::zero(),
             },
-            justified_epoch,
+            source_epoch,
-            justified_block_root,
+            source_root,
         })
     }
 
@@ -564,66 +555,13 @@ where
         }
     }
 
-    /// Dumps the entire canonical chain, from the head to genesis to a vector for analysis.
-    ///
-    /// This could be a very expensive operation and should only be done in testing/analysis
-    /// activities.
-    pub fn chain_dump(&self) -> Result<Vec<CheckPoint>, Error> {
-        let mut dump = vec![];
-
-        let mut last_slot = CheckPoint {
-            beacon_block: self.head().beacon_block.clone(),
-            beacon_block_root: self.head().beacon_block_root,
-            beacon_state: self.head().beacon_state.clone(),
-            beacon_state_root: self.head().beacon_state_root,
-        };
-
-        dump.push(last_slot.clone());
-
-        loop {
-            let beacon_block_root = last_slot.beacon_block.parent_root;
-
-            if beacon_block_root == self.spec.zero_hash {
-                break; // Genesis has been reached.
-            }
-
-            let beacon_block = self
-                .block_store
-                .get_deserialized(&beacon_block_root)?
-                .ok_or_else(|| {
-                    Error::DBInconsistent(format!("Missing block {}", beacon_block_root))
-                })?;
-            let beacon_state_root = beacon_block.state_root;
-            let beacon_state = self
-                .state_store
-                .get_deserialized(&beacon_state_root)?
-                .ok_or_else(|| {
-                    Error::DBInconsistent(format!("Missing state {}", beacon_state_root))
-                })?;
-
-            let slot = CheckPoint {
-                beacon_block,
-                beacon_block_root,
-                beacon_state,
-                beacon_state_root,
-            };
-
-            dump.push(slot.clone());
-            last_slot = slot;
-        }
-
-        dump.reverse();
-
-        Ok(dump)
-    }
-
     /// Accept some block and attempt to add it to block DAG.
     ///
     /// Will accept blocks from prior slots, however it will reject any block from a future slot.
     pub fn process_block(&self, block: BeaconBlock) -> Result<BlockProcessingOutcome, Error> {
-        debug!("Processing block with slot {}...", block.slot());
+        debug!("Processing block with slot {}...", block.slot);
 
-        let block_root = block.canonical_root();
+        let block_root = block.block_header().canonical_root();
 
         let present_slot = self.present_slot();
 
@@ -635,9 +573,9 @@ where
 
         // Load the blocks parent block from the database, returning invalid if that block is not
         // found.
-        let parent_block_root = block.parent_root;
+        let parent_block_root = block.previous_block_root;
-        let parent_block = match self.block_store.get_reader(&parent_block_root)? {
+        let parent_block = match self.block_store.get_deserialized(&parent_block_root)? {
-            Some(parent_root) => parent_root,
+            Some(previous_block_root) => previous_block_root,
             None => {
                 return Ok(BlockProcessingOutcome::InvalidBlock(
                     InvalidBlock::ParentUnknown,
@@ -647,23 +585,20 @@ where
 
         // Load the parent blocks state from the database, returning an error if it is not found.
         // It is an error because if know the parent block we should also know the parent state.
-        let parent_state_root = parent_block.state_root();
+        let parent_state_root = parent_block.state_root;
         let parent_state = self
             .state_store
-            .get_reader(&parent_state_root)?
+            .get_deserialized(&parent_state_root)?
-            .ok_or_else(|| Error::DBInconsistent(format!("Missing state {}", parent_state_root)))?
+            .ok_or_else(|| Error::DBInconsistent(format!("Missing state {}", parent_state_root)))?;
-            .into_beacon_state()
-            .ok_or_else(|| {
-                Error::DBInconsistent(format!("State SSZ invalid {}", parent_state_root))
-            })?;
 
         // TODO: check the block proposer signature BEFORE doing a state transition. This will
         // significantly lower exposure surface to DoS attacks.
 
         // Transition the parent state to the present slot.
         let mut state = parent_state;
+        let previous_block_header = parent_block.block_header();
         for _ in state.slot.as_u64()..present_slot.as_u64() {
-            if let Err(e) = per_slot_processing(&mut state, parent_block_root, &self.spec) {
+            if let Err(e) = per_slot_processing(&mut state, &previous_block_header, &self.spec) {
                 return Ok(BlockProcessingOutcome::InvalidBlock(
                     InvalidBlock::SlotProcessingError(e),
                 ));
@@ -739,22 +674,22 @@ where
             attestations.len()
         );
 
-        let parent_root = *state
+        let previous_block_root = *state
-            .get_block_root(state.slot.saturating_sub(1_u64), &self.spec)
+            .get_block_root(state.slot - 1, &self.spec)
-            .ok_or_else(|| BlockProductionError::UnableToGetBlockRootFromState)?;
+            .map_err(|_| BlockProductionError::UnableToGetBlockRootFromState)?;
 
         let mut block = BeaconBlock {
             slot: state.slot,
-            parent_root,
+            previous_block_root,
             state_root: Hash256::zero(), // Updated after the state is calculated.
+            signature: self.spec.empty_signature.clone(), // To be completed by a validator.
+            body: BeaconBlockBody {
                 randao_reveal,
                 eth1_data: Eth1Data {
                     // TODO: replace with real data
                     deposit_root: Hash256::zero(),
                     block_hash: Hash256::zero(),
                 },
-            signature: self.spec.empty_signature.clone(), // To be completed by a validator.
-            body: BeaconBlockBody {
                 proposer_slashings: self.get_proposer_slashings_for_block(),
                 attester_slashings: self.get_attester_slashings_for_block(),
                 attestations,
@@ -802,6 +737,59 @@ where
 
         Ok(())
     }
+
+    /// Dumps the entire canonical chain, from the head to genesis to a vector for analysis.
+    ///
+    /// This could be a very expensive operation and should only be done in testing/analysis
+    /// activities.
+    pub fn chain_dump(&self) -> Result<Vec<CheckPoint>, Error> {
+        let mut dump = vec![];
+
+        let mut last_slot = CheckPoint {
+            beacon_block: self.head().beacon_block.clone(),
+            beacon_block_root: self.head().beacon_block_root,
+            beacon_state: self.head().beacon_state.clone(),
+            beacon_state_root: self.head().beacon_state_root,
+        };
+
+        dump.push(last_slot.clone());
+
+        loop {
+            let beacon_block_root = last_slot.beacon_block.previous_block_root;
+
+            if beacon_block_root == self.spec.zero_hash {
+                break; // Genesis has been reached.
+            }
+
+            let beacon_block = self
+                .block_store
+                .get_deserialized(&beacon_block_root)?
+                .ok_or_else(|| {
+                    Error::DBInconsistent(format!("Missing block {}", beacon_block_root))
+                })?;
+            let beacon_state_root = beacon_block.state_root;
+            let beacon_state = self
+                .state_store
+                .get_deserialized(&beacon_state_root)?
+                .ok_or_else(|| {
+                    Error::DBInconsistent(format!("Missing state {}", beacon_state_root))
+                })?;
+
+            let slot = CheckPoint {
+                beacon_block,
+                beacon_block_root,
+                beacon_state,
+                beacon_state_root,
+            };
+
+            dump.push(slot.clone());
+            last_slot = slot;
+        }
+
+        dump.reverse();
+
+        Ok(dump)
+    }
 }
 
 impl From<DBError> for Error {

beacon_node/beacon_chain/test_harness/specs/validator_registry.yaml

@@ -9,6 +9,7 @@ test_cases:
       deposits_for_chain_start: 1000
       num_slots: 64
       skip_slots: [2, 3]
+      persistent_committee_period: 0
       deposits:
           # At slot 1, create a new validator deposit of 5 ETH.
         - slot: 1

beacon_node/beacon_chain/test_harness/src/beacon_chain_harness.rs

@@ -46,8 +46,8 @@ impl BeaconChainHarness {
             TestingBeaconStateBuilder::from_default_keypairs_file_if_exists(validator_count, &spec);
         let (genesis_state, keypairs) = state_builder.build();
 
-        let state_root = Hash256::from_slice(&genesis_state.hash_tree_root());
+        let mut genesis_block = BeaconBlock::empty(&spec);
-        let genesis_block = BeaconBlock::genesis(state_root, &spec);
+        genesis_block.state_root = Hash256::from_slice(&genesis_state.hash_tree_root());
 
         // Create the Beacon Chain
         let beacon_chain = Arc::new(
@@ -127,8 +127,8 @@ impl BeaconChainHarness {
             .get_crosslink_committees_at_slot(present_slot, &self.spec)
             .unwrap()
             .iter()
-            .fold(vec![], |mut acc, (committee, _slot)| {
+            .fold(vec![], |mut acc, c| {
-                acc.append(&mut committee.clone());
+                acc.append(&mut c.committee.clone());
                 acc
             });
         let attesting_validators: HashSet<usize> =
@@ -233,6 +233,27 @@ impl BeaconChainHarness {
         Some(Signature::new(message, domain, &validator.keypair.sk))
     }
 
+    /// Returns the current `Fork` of the `beacon_chain`.
+    pub fn fork(&self) -> Fork {
+        self.beacon_chain.state.read().fork.clone()
+    }
+
+    /// Returns the current `epoch` of the `beacon_chain`.
+    pub fn epoch(&self) -> Epoch {
+        self.beacon_chain
+            .state
+            .read()
+            .slot
+            .epoch(self.spec.slots_per_epoch)
+    }
+
+    /// Returns the keypair for some validator index.
+    pub fn validator_keypair(&self, validator_index: usize) -> Option<&Keypair> {
+        self.validators
+            .get(validator_index)
+            .and_then(|v| Some(&v.keypair))
+    }
+
     /// Submit a deposit to the `BeaconChain` and, if given a keypair, create a new
     /// `ValidatorHarness` instance for this validator.
     ///

beacon_node/beacon_chain/test_harness/src/test_case.rs

@@ -3,12 +3,11 @@
 
 use crate::beacon_chain_harness::BeaconChainHarness;
 use beacon_chain::CheckPoint;
-use bls::get_withdrawal_credentials;
 use log::{info, warn};
 use ssz::SignedRoot;
 use types::*;
 
-use types::test_utils::{TestingAttesterSlashingBuilder, TestingProposerSlashingBuilder};
+use types::test_utils::*;
 use yaml_rust::Yaml;
 
 mod config;
@@ -63,6 +62,10 @@ impl TestCase {
             spec.slots_per_epoch = n;
         }
 
+        if let Some(n) = self.config.persistent_committee_period {
+            spec.persistent_committee_period = n;
+        }
+
         spec
     }
 
@@ -222,27 +225,20 @@ impl TestCase {
 }
 
 /// Builds a `Deposit` this is valid for the given `BeaconChainHarness` at its next slot.
-fn build_transfer(harness: &BeaconChainHarness, from: u64, to: u64, amount: u64) -> Transfer {
+fn build_transfer(
+    harness: &BeaconChainHarness,
+    sender: u64,
+    recipient: u64,
+    amount: u64,
+) -> Transfer {
     let slot = harness.beacon_chain.state.read().slot + 1;
 
-    let mut transfer = Transfer {
+    let mut builder = TestingTransferBuilder::new(sender, recipient, amount, slot);
-        from,
-        to,
-        amount,
-        fee: 0,
-        slot,
-        pubkey: harness.validators[from as usize].keypair.pk.clone(),
-        signature: Signature::empty_signature(),
-    };
 
-    let message = transfer.signed_root();
+    let keypair = harness.validator_keypair(sender as usize).unwrap();
-    let epoch = slot.epoch(harness.spec.slots_per_epoch);
+    builder.sign(keypair.clone(), &harness.fork(), &harness.spec);
 
-    transfer.signature = harness
+    builder.build()
-        .validator_sign(from as usize, &message[..], epoch, Domain::Transfer)
-        .expect("Unable to sign Transfer");
-
-    transfer
 }
 
 /// Builds a `Deposit` this is valid for the given `BeaconChainHarness`.
@@ -255,41 +251,12 @@ fn build_deposit(
     index_offset: u64,
 ) -> (Deposit, Keypair) {
     let keypair = Keypair::random();
-    let withdrawal_credentials = Hash256::from_slice(
-        &get_withdrawal_credentials(&keypair.pk, harness.spec.bls_withdrawal_prefix_byte)[..],
-    );
-    let proof_of_possession = DepositInput::create_proof_of_possession(
-        &keypair,
-        &withdrawal_credentials,
-        harness.spec.get_domain(
-            harness
-                .beacon_chain
-                .state
-                .read()
-                .current_epoch(&harness.spec),
-            Domain::Deposit,
-            &harness.beacon_chain.state.read().fork,
-        ),
-    );
-    let index = harness.beacon_chain.state.read().deposit_index + index_offset;
 
-    let deposit = Deposit {
+    let mut builder = TestingDepositBuilder::new(keypair.pk.clone(), amount);
-        // Note: `branch` and `index` will need to be updated once the spec defines their
+    builder.set_index(harness.beacon_chain.state.read().deposit_index + index_offset);
-        // validity.
+    builder.sign(&keypair, harness.epoch(), &harness.fork(), &harness.spec);
-        branch: vec![],
-        index,
-        deposit_data: DepositData {
-            amount,
-            timestamp: 1,
-            deposit_input: DepositInput {
-                pubkey: keypair.pk.clone(),
-                withdrawal_credentials,
-                proof_of_possession,
-            },
-        },
-    };
 
-    (deposit, keypair)
+    (builder.build(), keypair)
 }
 
 /// Builds a `VoluntaryExit` this is valid for the given `BeaconChainHarness`.

beacon_node/beacon_chain/test_harness/src/test_case/config.rs

@@ -20,6 +20,8 @@ pub struct Config {
     pub deposits_for_chain_start: usize,
     /// Number of slots in an epoch.
     pub slots_per_epoch: Option<u64>,
+    /// Affects the number of epochs a validator must be active before they can withdraw.
+    pub persistent_committee_period: Option<u64>,
     /// Number of slots to build before ending execution.
     pub num_slots: u64,
     /// Number of slots that should be skipped due to inactive validator.
@@ -45,6 +47,7 @@ impl Config {
             deposits_for_chain_start: as_usize(&yaml, "deposits_for_chain_start")
                 .expect("Must specify validator count"),
             slots_per_epoch: as_u64(&yaml, "slots_per_epoch"),
+            persistent_committee_period: as_u64(&yaml, "persistent_committee_period"),
             num_slots: as_u64(&yaml, "num_slots").expect("Must specify `config.num_slots`"),
             skip_slots: as_vec_u64(yaml, "skip_slots"),
             deposits: parse_deposits(&yaml),

beacon_node/db/src/stores/beacon_block_store.rs

@@ -2,7 +2,7 @@ use super::BLOCKS_DB_COLUMN as DB_COLUMN;
 use super::{ClientDB, DBError};
 use ssz::Decodable;
 use std::sync::Arc;
-use types::{readers::BeaconBlockReader, BeaconBlock, Hash256, Slot};
+use types::{BeaconBlock, Hash256, Slot};
 
 #[derive(Clone, Debug, PartialEq)]
 pub enum BeaconBlockAtSlotError {
@@ -38,23 +38,6 @@ impl<T: ClientDB> BeaconBlockStore<T> {
         }
     }
 
-    /// Retuns an object implementing `BeaconBlockReader`, or `None` (if hash not known).
-    ///
-    /// Note: Presently, this function fully deserializes a `BeaconBlock` and returns that. In the
-    /// future, it would be ideal to return an object capable of reading directly from serialized
-    /// SSZ bytes.
-    pub fn get_reader(&self, hash: &Hash256) -> Result<Option<impl BeaconBlockReader>, DBError> {
-        match self.get(&hash)? {
-            None => Ok(None),
-            Some(ssz) => {
-                let (block, _) = BeaconBlock::ssz_decode(&ssz, 0).map_err(|_| DBError {
-                    message: "Bad BeaconBlock SSZ.".to_string(),
-                })?;
-                Ok(Some(block))
-            }
-        }
-    }
-
     /// Retrieve the block at a slot given a "head_hash" and a slot.
     ///
     /// A "head_hash" must be a block hash with a slot number greater than or equal to the desired
@@ -72,17 +55,17 @@ impl<T: ClientDB> BeaconBlockStore<T> {
         &self,
         head_hash: &Hash256,
         slot: Slot,
-    ) -> Result<Option<(Hash256, impl BeaconBlockReader)>, BeaconBlockAtSlotError> {
+    ) -> Result<Option<(Hash256, BeaconBlock)>, BeaconBlockAtSlotError> {
         let mut current_hash = *head_hash;
 
         loop {
-            if let Some(block_reader) = self.get_reader(&current_hash)? {
+            if let Some(block) = self.get_deserialized(&current_hash)? {
-                if block_reader.slot() == slot {
+                if block.slot == slot {
-                    break Ok(Some((current_hash, block_reader)));
+                    break Ok(Some((current_hash, block)));
-                } else if block_reader.slot() < slot {
+                } else if block.slot < slot {
                     break Ok(None);
                 } else {
-                    current_hash = block_reader.parent_root();
+                    current_hash = block.previous_block_root;
                 }
             } else {
                 break Err(BeaconBlockAtSlotError::UnknownBeaconBlock(current_hash));
@@ -228,7 +211,7 @@ mod tests {
         for i in 0..block_count {
             let mut block = BeaconBlock::random_for_test(&mut rng);
 
-            block.parent_root = parent_hashes[i];
+            block.previous_block_root = parent_hashes[i];
             block.slot = slots[i];
 
             let ssz = ssz_encode(&block);
@@ -240,12 +223,12 @@ mod tests {
         // Test that certain slots can be reached from certain hashes.
         let test_cases = vec![(4, 4), (4, 3), (4, 2), (4, 1), (4, 0)];
         for (hashes_index, slot_index) in test_cases {
-            let (matched_block_hash, reader) = bs
+            let (matched_block_hash, block) = bs
                 .block_at_slot(&hashes[hashes_index], slots[slot_index])
                 .unwrap()
                 .unwrap();
             assert_eq!(matched_block_hash, hashes[slot_index]);
-            assert_eq!(reader.slot(), slots[slot_index]);
+            assert_eq!(block.slot, slots[slot_index]);
         }
 
         let ssz = bs.block_at_slot(&hashes[4], Slot::new(2)).unwrap();

beacon_node/db/src/stores/beacon_state_store.rs

@@ -2,7 +2,7 @@ use super::STATES_DB_COLUMN as DB_COLUMN;
 use super::{ClientDB, DBError};
 use ssz::Decodable;
 use std::sync::Arc;
-use types::{readers::BeaconStateReader, BeaconState, Hash256};
+use types::{BeaconState, Hash256};
 
 pub struct BeaconStateStore<T>
 where
@@ -30,23 +30,6 @@ impl<T: ClientDB> BeaconStateStore<T> {
             }
         }
     }
-
-    /// Retuns an object implementing `BeaconStateReader`, or `None` (if hash not known).
-    ///
-    /// Note: Presently, this function fully deserializes a `BeaconState` and returns that. In the
-    /// future, it would be ideal to return an object capable of reading directly from serialized
-    /// SSZ bytes.
-    pub fn get_reader(&self, hash: &Hash256) -> Result<Option<impl BeaconStateReader>, DBError> {
-        match self.get(&hash)? {
-            None => Ok(None),
-            Some(ssz) => {
-                let (state, _) = BeaconState::ssz_decode(&ssz, 0).map_err(|_| DBError {
-                    message: "Bad State SSZ.".to_string(),
-                })?;
-                Ok(Some(state))
-            }
-        }
-    }
 }
 
 #[cfg(test)]
@@ -72,8 +55,7 @@ mod tests {
 
         store.put(&state_root, &ssz_encode(&state)).unwrap();
 
-        let reader = store.get_reader(&state_root).unwrap().unwrap();
+        let decoded = store.get_deserialized(&state_root).unwrap().unwrap();
-        let decoded = reader.into_beacon_state().unwrap();
 
         assert_eq!(state, decoded);
     }

beacon_node/src/main.rs

@@ -18,10 +18,8 @@ use slog::{error, info, o, Drain};
 use slot_clock::SystemTimeSlotClock;
 use ssz::TreeHash;
 use std::sync::Arc;
-use types::{
+use types::test_utils::TestingBeaconStateBuilder;
-    beacon_state::BeaconStateBuilder, BeaconBlock, ChainSpec, Deposit, DepositData, DepositInput,
+use types::*;
-    Domain, Eth1Data, Fork, Hash256, Keypair,
-};
 
 fn main() {
     let decorator = slog_term::TermDecorator::new().build();
@@ -79,64 +77,18 @@ fn main() {
     let block_store = Arc::new(BeaconBlockStore::new(db.clone()));
     let state_store = Arc::new(BeaconStateStore::new(db.clone()));
 
+    let state_builder = TestingBeaconStateBuilder::from_deterministic_keypairs(8, &spec);
+    let (genesis_state, _keypairs) = state_builder.build();
+
+    let mut genesis_block = BeaconBlock::empty(&spec);
+    genesis_block.state_root = Hash256::from_slice(&genesis_state.hash_tree_root());
+
     // Slot clock
-    let genesis_time = 1_549_935_547; // 12th Feb 2018 (arbitrary value in the past).
+    let slot_clock = SystemTimeSlotClock::new(genesis_state.genesis_time, spec.seconds_per_slot)
-    let slot_clock = SystemTimeSlotClock::new(genesis_time, spec.seconds_per_slot)
         .expect("Unable to load SystemTimeSlotClock");
     // Choose the fork choice
     let fork_choice = BitwiseLMDGhost::new(block_store.clone(), state_store.clone());
 
-    /*
-     * Generate some random data to start a chain with.
-     *
-     * This is will need to be replace for production usage.
-     */
-    let latest_eth1_data = Eth1Data {
-        deposit_root: Hash256::zero(),
-        block_hash: Hash256::zero(),
-    };
-    let keypairs: Vec<Keypair> = (0..10)
-        .collect::<Vec<usize>>()
-        .iter()
-        .map(|_| Keypair::random())
-        .collect();
-
-    let initial_validator_deposits: Vec<Deposit> = keypairs
-        .iter()
-        .map(|keypair| Deposit {
-            branch: vec![], // branch verification is not specified.
-            index: 0,       // index verification is not specified.
-            deposit_data: DepositData {
-                amount: 32_000_000_000, // 32 ETH (in Gwei)
-                timestamp: genesis_time - 1,
-                deposit_input: DepositInput {
-                    pubkey: keypair.pk.clone(),
-                    withdrawal_credentials: Hash256::zero(), // Withdrawal not possible.
-                    proof_of_possession: DepositInput::create_proof_of_possession(
-                        &keypair,
-                        &Hash256::zero(),
-                        spec.get_domain(
-                            // Get domain from genesis fork_version
-                            spec.genesis_epoch,
-                            Domain::Deposit,
-                            &Fork {
-                                previous_version: spec.genesis_fork_version,
-                                current_version: spec.genesis_fork_version,
-                                epoch: spec.genesis_epoch,
-                            },
-                        ),
-                    ),
-                },
-            },
-        })
-        .collect();
-
-    let mut state_builder = BeaconStateBuilder::new(genesis_time, latest_eth1_data, &spec);
-    state_builder.process_initial_deposits(&initial_validator_deposits, &spec);
-    let genesis_state = state_builder.build(&spec).unwrap();
-    let state_root = Hash256::from_slice(&genesis_state.hash_tree_root());
-    let genesis_block = BeaconBlock::genesis(state_root, &spec);
-
     // Genesis chain
     let _chain_result = BeaconChain::from_genesis(
         state_store.clone(),

eth2/block_proposer/src/lib.rs

@@ -4,7 +4,7 @@ mod traits;
 use slot_clock::SlotClock;
 use ssz::{SignedRoot, TreeHash};
 use std::sync::Arc;
-use types::{BeaconBlock, ChainSpec, Domain, Hash256, Proposal, Slot};
+use types::{BeaconBlock, ChainSpec, Domain, Slot};
 
 pub use self::traits::{
     BeaconNode, BeaconNodeError, DutiesReader, DutiesReaderError, PublishOutcome, Signer,
@@ -158,7 +158,7 @@ impl<T: SlotClock, U: BeaconNode, V: DutiesReader, W: Signer> BlockProducer<T, U
             if self.safe_to_produce(&block) {
                 let domain = self.spec.get_domain(
                     slot.epoch(self.spec.slots_per_epoch),
-                    Domain::Proposal,
+                    Domain::BeaconBlock,
                     &fork,
                 );
                 if let Some(block) = self.sign_block(block, domain) {
@@ -182,16 +182,9 @@ impl<T: SlotClock, U: BeaconNode, V: DutiesReader, W: Signer> BlockProducer<T, U
     fn sign_block(&mut self, mut block: BeaconBlock, domain: u64) -> Option<BeaconBlock> {
         self.store_produce(&block);
 
-        let proposal = Proposal {
-            slot: block.slot,
-            shard: self.spec.beacon_chain_shard_number,
-            block_root: Hash256::from_slice(&block.signed_root()[..]),
-            signature: block.signature.clone(),
-        };
-
         match self
             .signer
-            .sign_block_proposal(&proposal.signed_root()[..], domain)
+            .sign_block_proposal(&block.signed_root()[..], domain)
         {
             None => None,
             Some(signature) => {

eth2/block_proposer/src/test_utils/epoch_map.rs

@@ -28,8 +28,8 @@ impl DutiesReader for EpochMap {
 
     fn fork(&self) -> Result<Fork, DutiesReaderError> {
         Ok(Fork {
-            previous_version: 0,
+            previous_version: [0; 4],
-            current_version: 0,
+            current_version: [0; 4],
             epoch: Epoch::new(0),
         })
     }

eth2/fork_choice/src/bitwise_lmd_ghost.rs

@@ -10,10 +10,7 @@ use db::{
 use log::{debug, trace};
 use std::collections::HashMap;
 use std::sync::Arc;
-use types::{
+use types::{BeaconBlock, ChainSpec, Hash256, Slot, SlotHeight};
-    readers::BeaconBlockReader, validator_registry::get_active_validator_indices, BeaconBlock,
-    ChainSpec, Hash256, Slot, SlotHeight,
-};
 
 //TODO: Pruning - Children
 //TODO: Handle Syncing
@@ -93,10 +90,8 @@ where
             .get_deserialized(&state_root)?
             .ok_or_else(|| ForkChoiceError::MissingBeaconState(*state_root))?;
 
-        let active_validator_indices = get_active_validator_indices(
+        let active_validator_indices =
-            &current_state.validator_registry[..],
+            current_state.get_active_validator_indices(block_slot.epoch(spec.slots_per_epoch));
-            block_slot.epoch(spec.slots_per_epoch),
-        );
 
         for index in active_validator_indices {
             let balance = std::cmp::min(
@@ -255,17 +250,17 @@ impl<T: ClientDB + Sized> ForkChoice for BitwiseLMDGhost<T> {
         // get the height of the parent
         let parent_height = self
             .block_store
-            .get_deserialized(&block.parent_root)?
+            .get_deserialized(&block.previous_block_root)?
-            .ok_or_else(|| ForkChoiceError::MissingBeaconBlock(block.parent_root))?
+            .ok_or_else(|| ForkChoiceError::MissingBeaconBlock(block.previous_block_root))?
-            .slot()
+            .slot
             .height(spec.genesis_slot);
 
-        let parent_hash = &block.parent_root;
+        let parent_hash = &block.previous_block_root;
 
         // add the new block to the children of parent
         (*self
             .children
-            .entry(block.parent_root)
+            .entry(block.previous_block_root)
             .or_insert_with(|| vec![]))
         .push(block_hash.clone());
 
@@ -309,7 +304,7 @@ impl<T: ClientDB + Sized> ForkChoice for BitwiseLMDGhost<T> {
                 .block_store
                 .get_deserialized(&target_block_root)?
                 .ok_or_else(|| ForkChoiceError::MissingBeaconBlock(*target_block_root))?
-                .slot()
+                .slot
                 .height(spec.genesis_slot);
 
             // get the height of the past target block
@@ -317,7 +312,7 @@ impl<T: ClientDB + Sized> ForkChoice for BitwiseLMDGhost<T> {
                 .block_store
                 .get_deserialized(&attestation_target)?
                 .ok_or_else(|| ForkChoiceError::MissingBeaconBlock(*attestation_target))?
-                .slot()
+                .slot
                 .height(spec.genesis_slot);
             // update the attestation only if the new target is higher
             if past_block_height < block_height {
@@ -343,8 +338,8 @@ impl<T: ClientDB + Sized> ForkChoice for BitwiseLMDGhost<T> {
             .get_deserialized(&justified_block_start)?
             .ok_or_else(|| ForkChoiceError::MissingBeaconBlock(*justified_block_start))?;
 
-        let block_slot = block.slot();
+        let block_slot = block.slot;
-        let state_root = block.state_root();
+        let state_root = block.state_root;
         let mut block_height = block_slot.height(spec.genesis_slot);
 
         let mut current_head = *justified_block_start;
@@ -434,7 +429,7 @@ impl<T: ClientDB + Sized> ForkChoice for BitwiseLMDGhost<T> {
                 .block_store
                 .get_deserialized(&current_head)?
                 .ok_or_else(|| ForkChoiceError::MissingBeaconBlock(current_head))?
-                .slot()
+                .slot
                 .height(spec.genesis_slot);
             // prune the latest votes for votes that are not part of current chosen chain
             // more specifically, only keep votes that have head as an ancestor

eth2/fork_choice/src/longest_chain.rs

@@ -34,7 +34,7 @@ impl<T: ClientDB + Sized> ForkChoice for LongestChain<T> {
     ) -> Result<(), ForkChoiceError> {
         // add the block hash to head_block_hashes removing the parent if it exists
         self.head_block_hashes
-            .retain(|hash| *hash != block.parent_root);
+            .retain(|hash| *hash != block.previous_block_root);
         self.head_block_hashes.push(*block_hash);
         Ok(())
     }

eth2/fork_choice/src/optimized_lmd_ghost.rs

@@ -10,10 +10,7 @@ use log::{debug, trace};
 use std::cmp::Ordering;
 use std::collections::HashMap;
 use std::sync::Arc;
-use types::{
+use types::{BeaconBlock, ChainSpec, Hash256, Slot, SlotHeight};
-    readers::BeaconBlockReader, validator_registry::get_active_validator_indices, BeaconBlock,
-    ChainSpec, Hash256, Slot, SlotHeight,
-};
 
 //TODO: Pruning - Children
 //TODO: Handle Syncing
@@ -93,10 +90,8 @@ where
             .get_deserialized(&state_root)?
             .ok_or_else(|| ForkChoiceError::MissingBeaconState(*state_root))?;
 
-        let active_validator_indices = get_active_validator_indices(
+        let active_validator_indices =
-            &current_state.validator_registry[..],
+            current_state.get_active_validator_indices(block_slot.epoch(spec.slots_per_epoch));
-            block_slot.epoch(spec.slots_per_epoch),
-        );
 
         for index in active_validator_indices {
             let balance = std::cmp::min(
@@ -226,17 +221,17 @@ impl<T: ClientDB + Sized> ForkChoice for OptimizedLMDGhost<T> {
         // get the height of the parent
         let parent_height = self
             .block_store
-            .get_deserialized(&block.parent_root)?
+            .get_deserialized(&block.previous_block_root)?
-            .ok_or_else(|| ForkChoiceError::MissingBeaconBlock(block.parent_root))?
+            .ok_or_else(|| ForkChoiceError::MissingBeaconBlock(block.previous_block_root))?
-            .slot()
+            .slot
             .height(spec.genesis_slot);
 
-        let parent_hash = &block.parent_root;
+        let parent_hash = &block.previous_block_root;
 
         // add the new block to the children of parent
         (*self
             .children
-            .entry(block.parent_root)
+            .entry(block.previous_block_root)
             .or_insert_with(|| vec![]))
         .push(block_hash.clone());
 
@@ -280,7 +275,7 @@ impl<T: ClientDB + Sized> ForkChoice for OptimizedLMDGhost<T> {
                 .block_store
                 .get_deserialized(&target_block_root)?
                 .ok_or_else(|| ForkChoiceError::MissingBeaconBlock(*target_block_root))?
-                .slot()
+                .slot
                 .height(spec.genesis_slot);
 
             // get the height of the past target block
@@ -288,7 +283,7 @@ impl<T: ClientDB + Sized> ForkChoice for OptimizedLMDGhost<T> {
                 .block_store
                 .get_deserialized(&attestation_target)?
                 .ok_or_else(|| ForkChoiceError::MissingBeaconBlock(*attestation_target))?
-                .slot()
+                .slot
                 .height(spec.genesis_slot);
             // update the attestation only if the new target is higher
             if past_block_height < block_height {
@@ -314,8 +309,8 @@ impl<T: ClientDB + Sized> ForkChoice for OptimizedLMDGhost<T> {
             .get_deserialized(&justified_block_start)?
             .ok_or_else(|| ForkChoiceError::MissingBeaconBlock(*justified_block_start))?;
 
-        let block_slot = block.slot();
+        let block_slot = block.slot;
-        let state_root = block.state_root();
+        let state_root = block.state_root;
         let mut block_height = block_slot.height(spec.genesis_slot);
 
         let mut current_head = *justified_block_start;
@@ -405,7 +400,7 @@ impl<T: ClientDB + Sized> ForkChoice for OptimizedLMDGhost<T> {
                 .block_store
                 .get_deserialized(&current_head)?
                 .ok_or_else(|| ForkChoiceError::MissingBeaconBlock(current_head))?
-                .slot()
+                .slot
                 .height(spec.genesis_slot);
             // prune the latest votes for votes that are not part of current chosen chain
             // more specifically, only keep votes that have head as an ancestor

eth2/fork_choice/src/slow_lmd_ghost.rs

@@ -8,10 +8,7 @@ use db::{
 use log::{debug, trace};
 use std::collections::HashMap;
 use std::sync::Arc;
-use types::{
+use types::{BeaconBlock, ChainSpec, Hash256, Slot};
-    readers::BeaconBlockReader, validator_registry::get_active_validator_indices, BeaconBlock,
-    ChainSpec, Hash256, Slot,
-};
 
 //TODO: Pruning and syncing
 
@@ -62,10 +59,8 @@ where
             .get_deserialized(&state_root)?
             .ok_or_else(|| ForkChoiceError::MissingBeaconState(*state_root))?;
 
-        let active_validator_indices = get_active_validator_indices(
+        let active_validator_indices =
-            &current_state.validator_registry[..],
+            current_state.get_active_validator_indices(block_slot.epoch(spec.slots_per_epoch));
-            block_slot.epoch(spec.slots_per_epoch),
-        );
 
         for index in active_validator_indices {
             let balance = std::cmp::min(
@@ -95,7 +90,7 @@ where
             .block_store
             .get_deserialized(&block_root)?
             .ok_or_else(|| ForkChoiceError::MissingBeaconBlock(*block_root))?
-            .slot();
+            .slot;
 
         for (vote_hash, votes) in latest_votes.iter() {
             let (root_at_slot, _) = self
@@ -122,7 +117,7 @@ impl<T: ClientDB + Sized> ForkChoice for SlowLMDGhost<T> {
         // add the new block to the children of parent
         (*self
             .children
-            .entry(block.parent_root)
+            .entry(block.previous_block_root)
             .or_insert_with(|| vec![]))
         .push(block_hash.clone());
 
@@ -155,7 +150,7 @@ impl<T: ClientDB + Sized> ForkChoice for SlowLMDGhost<T> {
                 .block_store
                 .get_deserialized(&target_block_root)?
                 .ok_or_else(|| ForkChoiceError::MissingBeaconBlock(*target_block_root))?
-                .slot()
+                .slot
                 .height(spec.genesis_slot);
 
             // get the height of the past target block
@@ -163,7 +158,7 @@ impl<T: ClientDB + Sized> ForkChoice for SlowLMDGhost<T> {
                 .block_store
                 .get_deserialized(&attestation_target)?
                 .ok_or_else(|| ForkChoiceError::MissingBeaconBlock(*attestation_target))?
-                .slot()
+                .slot
                 .height(spec.genesis_slot);
             // update the attestation only if the new target is higher
             if past_block_height < block_height {
@@ -186,9 +181,9 @@ impl<T: ClientDB + Sized> ForkChoice for SlowLMDGhost<T> {
             .get_deserialized(&justified_block_start)?
             .ok_or_else(|| ForkChoiceError::MissingBeaconBlock(*justified_block_start))?;
 
-        let start_state_root = start.state_root();
+        let start_state_root = start.state_root;
 
-        let latest_votes = self.get_latest_votes(&start_state_root, start.slot(), spec)?;
+        let latest_votes = self.get_latest_votes(&start_state_root, start.slot, spec)?;
 
         let mut head_hash = *justified_block_start;
 
@@ -220,13 +215,11 @@ impl<T: ClientDB + Sized> ForkChoice for SlowLMDGhost<T> {
                     head_vote_count = vote_count;
                 }
                 // resolve ties - choose smaller hash
-                else if vote_count == head_vote_count {
+                else if vote_count == head_vote_count && *child_hash < head_hash {
-                    if *child_hash < head_hash {
                     head_hash = *child_hash;
                 }
             }
         }
-        }
         Ok(head_hash)
     }
 }

eth2/fork_choice/tests/tests.rs

@@ -90,6 +90,8 @@ fn test_yaml_vectors(
     let randao_reveal = Signature::empty_signature();
     let signature = Signature::empty_signature();
     let body = BeaconBlockBody {
+        eth1_data,
+        randao_reveal,
         proposer_slashings: vec![],
         attester_slashings: vec![],
         attestations: vec![],
@@ -117,14 +119,14 @@ fn test_yaml_vectors(
             // default params for genesis
             let block_hash = id_to_hash(&block_id);
             let mut slot = spec.genesis_slot;
-            let parent_root = id_to_hash(&parent_id);
+            let previous_block_root = id_to_hash(&parent_id);
 
             // set the slot and parent based off the YAML. Start with genesis;
             // if not the genesis, update slot
             if parent_id != block_id {
                 // find parent slot
                 slot = *(block_slot
-                    .get(&parent_root)
+                    .get(&previous_block_root)
                     .expect("Parent should have a slot number"))
                     + 1;
             } else {
@@ -137,10 +139,8 @@ fn test_yaml_vectors(
             // build the BeaconBlock
             let beacon_block = BeaconBlock {
                 slot,
-                parent_root,
+                previous_block_root,
                 state_root: state_root.clone(),
-                randao_reveal: randao_reveal.clone(),
-                eth1_data: eth1_data.clone(),
                 signature: signature.clone(),
                 body: body.clone(),
             };
@@ -242,8 +242,9 @@ fn setup_inital_state(
 
     let spec = ChainSpec::foundation();
 
-    let state_builder =
+    let mut state_builder =
         TestingBeaconStateBuilder::from_single_keypair(num_validators, &Keypair::random(), &spec);
+    state_builder.build_caches(&spec).unwrap();
     let (state, _keypairs) = state_builder.build();
 
     let state_root = state.canonical_root();

eth2/state_processing/Cargo.toml

@@ -11,6 +11,9 @@ harness = false
 [dev-dependencies]
 criterion = "0.2"
 env_logger = "0.6.0"
+serde = "1.0"
+serde_derive = "1.0"
+serde_yaml = "0.8"
 
 [dependencies]
 bls = { path = "../utils/bls" }

eth2/state_processing/benches/bench_block_processing.rs

@@ -1,6 +1,5 @@
 use criterion::Criterion;
 use criterion::{black_box, Benchmark};
-use log::debug;
 use ssz::TreeHash;
 use state_processing::{
     per_block_processing,
@@ -10,195 +9,12 @@ use state_processing::{
         verify_block_signature,
     },
 };
-use types::test_utils::{TestingBeaconBlockBuilder, TestingBeaconStateBuilder};
 use types::*;
 
-/// Run the benchmarking suite on a foundation spec with 16,384 validators.
-pub fn bench_block_processing_n_validators(c: &mut Criterion, validator_count: usize) {
-    let spec = ChainSpec::foundation();
-
-    let (mut state, keypairs) = build_state(validator_count, &spec);
-    let block = build_block(&mut state, &keypairs, &spec);
-
-    assert_eq!(
-        block.body.proposer_slashings.len(),
-        spec.max_proposer_slashings as usize,
-        "The block should have the maximum possible proposer slashings"
-    );
-
-    assert_eq!(
-        block.body.attester_slashings.len(),
-        spec.max_attester_slashings as usize,
-        "The block should have the maximum possible attester slashings"
-    );
-
-    for attester_slashing in &block.body.attester_slashings {
-        let len_1 = attester_slashing
-            .slashable_attestation_1
-            .validator_indices
-            .len();
-        let len_2 = attester_slashing
-            .slashable_attestation_1
-            .validator_indices
-            .len();
-        assert!(
-            (len_1 == len_2) && (len_2 == spec.max_indices_per_slashable_vote as usize),
-            "Each attester slashing should have the maximum possible validator indices"
-        );
-    }
-
-    assert_eq!(
-        block.body.attestations.len(),
-        spec.max_attestations as usize,
-        "The block should have the maximum possible attestations."
-    );
-
-    assert_eq!(
-        block.body.deposits.len(),
-        spec.max_deposits as usize,
-        "The block should have the maximum possible deposits."
-    );
-
-    assert_eq!(
-        block.body.voluntary_exits.len(),
-        spec.max_voluntary_exits as usize,
-        "The block should have the maximum possible voluntary exits."
-    );
-
-    assert_eq!(
-        block.body.transfers.len(),
-        spec.max_transfers as usize,
-        "The block should have the maximum possible transfers."
-    );
-
-    bench_block_processing(
-        c,
-        &block,
-        &state,
-        &spec,
-        &format!("{}_validators", validator_count),
-    );
-}
-
-fn build_state(validator_count: usize, spec: &ChainSpec) -> (BeaconState, Vec<Keypair>) {
-    let mut builder =
-        TestingBeaconStateBuilder::from_default_keypairs_file_if_exists(validator_count, &spec);
-
-    // Set the state to be just before an epoch transition.
-    let target_slot = (spec.genesis_epoch + 4).end_slot(spec.slots_per_epoch);
-    builder.teleport_to_slot(target_slot, &spec);
-
-    // Builds all caches; benches will not contain shuffling/committee building times.
-    builder.build_caches(&spec).unwrap();
-
-    builder.build()
-}
-
-fn build_block(state: &mut BeaconState, keypairs: &[Keypair], spec: &ChainSpec) -> BeaconBlock {
-    let mut builder = TestingBeaconBlockBuilder::new(spec);
-
-    builder.set_slot(state.slot);
-
-    let proposer_index = state.get_beacon_proposer_index(state.slot, spec).unwrap();
-    let keypair = &keypairs[proposer_index];
-
-    builder.set_randao_reveal(&keypair.sk, &state.fork, spec);
-
-    // Used as a stream of validator indices for use in slashings, exits, etc.
-    let mut validators_iter = (0..keypairs.len() as u64).into_iter();
-
-    // Insert the maximum possible number of `ProposerSlashing` objects.
-    debug!(
-        "Inserting {} proposer slashings...",
-        spec.max_proposer_slashings
-    );
-    for _ in 0..spec.max_proposer_slashings {
-        let validator_index = validators_iter.next().expect("Insufficient validators.");
-
-        builder.insert_proposer_slashing(
-            validator_index,
-            &keypairs[validator_index as usize].sk,
-            &state.fork,
-            spec,
-        );
-    }
-
-    // Insert the maximum possible number of `AttesterSlashing` objects
-    debug!(
-        "Inserting {} attester slashings...",
-        spec.max_attester_slashings
-    );
-    for _ in 0..spec.max_attester_slashings {
-        let mut attesters: Vec<u64> = vec![];
-        let mut secret_keys: Vec<&SecretKey> = vec![];
-
-        for _ in 0..spec.max_indices_per_slashable_vote {
-            let validator_index = validators_iter.next().expect("Insufficient validators.");
-
-            attesters.push(validator_index);
-            secret_keys.push(&keypairs[validator_index as usize].sk);
-        }
-
-        builder.insert_attester_slashing(&attesters, &secret_keys, &state.fork, spec);
-    }
-
-    // Insert the maximum possible number of `Attestation` objects.
-    debug!("Inserting {} attestations...", spec.max_attestations);
-    let all_secret_keys: Vec<&SecretKey> = keypairs.iter().map(|keypair| &keypair.sk).collect();
-    builder
-        .fill_with_attestations(state, &all_secret_keys, spec)
-        .unwrap();
-
-    // Insert the maximum possible number of `Deposit` objects.
-    debug!("Inserting {} deposits...", spec.max_deposits);
-    for i in 0..spec.max_deposits {
-        builder.insert_deposit(32_000_000_000, state.deposit_index + i, state, spec);
-    }
-
-    // Insert the maximum possible number of `Exit` objects.
-    debug!("Inserting {} exits...", spec.max_voluntary_exits);
-    for _ in 0..spec.max_voluntary_exits {
-        let validator_index = validators_iter.next().expect("Insufficient validators.");
-
-        builder.insert_exit(
-            state,
-            validator_index,
-            &keypairs[validator_index as usize].sk,
-            spec,
-        );
-    }
-
-    // Insert the maximum possible number of `Transfer` objects.
-    debug!("Inserting {} transfers...", spec.max_transfers);
-    for _ in 0..spec.max_transfers {
-        let validator_index = validators_iter.next().expect("Insufficient validators.");
-
-        // Manually set the validator to be withdrawn.
-        state.validator_registry[validator_index as usize].withdrawable_epoch =
-            state.previous_epoch(spec);
-
-        builder.insert_transfer(
-            state,
-            validator_index,
-            validator_index,
-            1,
-            keypairs[validator_index as usize].clone(),
-            spec,
-        );
-    }
-
-    let mut block = builder.build(&keypair.sk, &state.fork, spec);
-
-    // Set the eth1 data to be different from the state.
-    block.eth1_data.block_hash = Hash256::from_slice(&vec![42; 32]);
-
-    block
-}
-
 /// Run the detailed benchmarking suite on the given `BeaconState`.
 ///
 /// `desc` will be added to the title of each bench.
-fn bench_block_processing(
+pub fn bench_block_processing(
     c: &mut Criterion,
     initial_block: &BeaconBlock,
     initial_state: &BeaconState,

eth2/state_processing/benches/bench_epoch_processing.rs

@@ -48,16 +48,6 @@ pub fn bench_epoch_processing_n_validators(c: &mut Criterion, validator_count: u
         "The state should have an attestation for each committee."
     );
 
-    // Assert that each attestation in the state has full participation.
-    let committee_size = validator_count / committees_per_epoch as usize;
-    for a in &state.latest_attestations {
-        assert_eq!(
-            a.aggregation_bitfield.num_set_bits(),
-            committee_size,
-            "Each attestation in the state should have full participation"
-        );
-    }
-
     // Assert that we will run the first arm of process_rewards_and_penalities
     let epochs_since_finality = state.next_epoch(&spec) - state.finalized_epoch;
     assert_eq!(

eth2/state_processing/benches/benches.rs

@@ -1,23 +1,103 @@
+use block_benching_builder::BlockBenchingBuilder;
 use criterion::Criterion;
 use criterion::{criterion_group, criterion_main};
 use env_logger::{Builder, Env};
+use log::info;
+use types::*;
 
 mod bench_block_processing;
 mod bench_epoch_processing;
+mod block_benching_builder;
 
 pub const VALIDATOR_COUNT: usize = 16_384;
 
-// `LOG_LEVEL == "debug"` gives logs, but they're very noisy and slow down benching.
+// `LOG_LEVEL == "info"` gives handy messages.
-pub const LOG_LEVEL: &str = "";
+pub const LOG_LEVEL: &str = "info";
 
-pub fn state_processing(c: &mut Criterion) {
+/// Build a worst-case block and benchmark processing it.
+pub fn block_processing_worst_case(c: &mut Criterion) {
     if LOG_LEVEL != "" {
         Builder::from_env(Env::default().default_filter_or(LOG_LEVEL)).init();
     }
+    info!(
+        "Building worst case block bench with {} validators",
+        VALIDATOR_COUNT
+    );
 
-    bench_epoch_processing::bench_epoch_processing_n_validators(c, VALIDATOR_COUNT);
+    // Use the specifications from the Eth2.0 spec.
-    bench_block_processing::bench_block_processing_n_validators(c, VALIDATOR_COUNT);
+    let spec = ChainSpec::foundation();
+
+    // Create a builder for configuring the block and state for benching.
+    let mut bench_builder = BlockBenchingBuilder::new(VALIDATOR_COUNT, &spec);
+
+    // Set the number of included operations to be maximum (e.g., `MAX_ATTESTATIONS`, etc.)
+    bench_builder.maximize_block_operations(&spec);
+
+    // Set the state and block to be in the last slot of the 4th epoch.
+    let last_slot_of_epoch = (spec.genesis_epoch + 4).end_slot(spec.slots_per_epoch);
+    bench_builder.set_slot(last_slot_of_epoch, &spec);
+
+    // Build all the state caches so the build times aren't included in the benches.
+    bench_builder.build_caches(&spec);
+
+    // Generate the block and state then run benches.
+    let (block, state) = bench_builder.build(&spec);
+    bench_block_processing::bench_block_processing(
+        c,
+        &block,
+        &state,
+        &spec,
+        &format!("{}_validators/worst_case", VALIDATOR_COUNT),
+    );
 }
 
-criterion_group!(benches, state_processing);
+/// Build a reasonable-case block and benchmark processing it.
+pub fn block_processing_reasonable_case(c: &mut Criterion) {
+    info!(
+        "Building reasonable case block bench with {} validators",
+        VALIDATOR_COUNT
+    );
+
+    // Use the specifications from the Eth2.0 spec.
+    let spec = ChainSpec::foundation();
+
+    // Create a builder for configuring the block and state for benching.
+    let mut bench_builder = BlockBenchingBuilder::new(VALIDATOR_COUNT, &spec);
+
+    // Set the number of included operations to what we might expect normally.
+    bench_builder.num_proposer_slashings = 0;
+    bench_builder.num_attester_slashings = 0;
+    bench_builder.num_attestations = (spec.shard_count / spec.slots_per_epoch) as usize;
+    bench_builder.num_deposits = 2;
+    bench_builder.num_exits = 2;
+    bench_builder.num_transfers = 2;
+
+    // Set the state and block to be in the last slot of the 4th epoch.
+    let last_slot_of_epoch = (spec.genesis_epoch + 4).end_slot(spec.slots_per_epoch);
+    bench_builder.set_slot(last_slot_of_epoch, &spec);
+
+    // Build all the state caches so the build times aren't included in the benches.
+    bench_builder.build_caches(&spec);
+
+    // Generate the block and state then run benches.
+    let (block, state) = bench_builder.build(&spec);
+    bench_block_processing::bench_block_processing(
+        c,
+        &block,
+        &state,
+        &spec,
+        &format!("{}_validators/reasonable_case", VALIDATOR_COUNT),
+    );
+}
+
+pub fn state_processing(c: &mut Criterion) {
+    bench_epoch_processing::bench_epoch_processing_n_validators(c, VALIDATOR_COUNT);
+}
+
+criterion_group!(
+    benches,
+    block_processing_reasonable_case,
+    block_processing_worst_case,
+    state_processing
+);
 criterion_main!(benches);

eth2/state_processing/benches/block_benching_builder.rs

@@ -0,0 +1,175 @@
+use log::info;
+use types::test_utils::{TestingBeaconBlockBuilder, TestingBeaconStateBuilder};
+use types::*;
+
+pub struct BlockBenchingBuilder {
+    pub state_builder: TestingBeaconStateBuilder,
+    pub block_builder: TestingBeaconBlockBuilder,
+
+    pub num_validators: usize,
+    pub num_proposer_slashings: usize,
+    pub num_attester_slashings: usize,
+    pub num_indices_per_slashable_vote: usize,
+    pub num_attestations: usize,
+    pub num_deposits: usize,
+    pub num_exits: usize,
+    pub num_transfers: usize,
+}
+
+impl BlockBenchingBuilder {
+    pub fn new(num_validators: usize, spec: &ChainSpec) -> Self {
+        let state_builder =
+            TestingBeaconStateBuilder::from_default_keypairs_file_if_exists(num_validators, &spec);
+        let block_builder = TestingBeaconBlockBuilder::new(spec);
+
+        Self {
+            state_builder,
+            block_builder,
+            num_validators: 0,
+            num_proposer_slashings: 0,
+            num_attester_slashings: 0,
+            num_indices_per_slashable_vote: spec.max_indices_per_slashable_vote as usize,
+            num_attestations: 0,
+            num_deposits: 0,
+            num_exits: 0,
+            num_transfers: 0,
+        }
+    }
+
+    pub fn maximize_block_operations(&mut self, spec: &ChainSpec) {
+        self.num_proposer_slashings = spec.max_proposer_slashings as usize;
+        self.num_attester_slashings = spec.max_attester_slashings as usize;
+        self.num_indices_per_slashable_vote = spec.max_indices_per_slashable_vote as usize;
+        self.num_attestations = spec.max_attestations as usize;
+        self.num_deposits = spec.max_deposits as usize;
+        self.num_exits = spec.max_voluntary_exits as usize;
+        self.num_transfers = spec.max_transfers as usize;
+    }
+
+    pub fn set_slot(&mut self, slot: Slot, spec: &ChainSpec) {
+        self.state_builder.teleport_to_slot(slot, &spec);
+    }
+
+    pub fn build_caches(&mut self, spec: &ChainSpec) {
+        // Builds all caches; benches will not contain shuffling/committee building times.
+        self.state_builder.build_caches(&spec).unwrap();
+    }
+
+    pub fn build(mut self, spec: &ChainSpec) -> (BeaconBlock, BeaconState) {
+        let (mut state, keypairs) = self.state_builder.build();
+        let builder = &mut self.block_builder;
+
+        builder.set_slot(state.slot);
+
+        let proposer_index = state.get_beacon_proposer_index(state.slot, spec).unwrap();
+        let keypair = &keypairs[proposer_index];
+
+        builder.set_randao_reveal(&keypair.sk, &state.fork, spec);
+
+        // Used as a stream of validator indices for use in slashings, exits, etc.
+        let mut validators_iter = (0..keypairs.len() as u64).into_iter();
+
+        // Insert `ProposerSlashing` objects.
+        for _ in 0..self.num_proposer_slashings {
+            let validator_index = validators_iter.next().expect("Insufficient validators.");
+
+            builder.insert_proposer_slashing(
+                validator_index,
+                &keypairs[validator_index as usize].sk,
+                &state.fork,
+                spec,
+            );
+        }
+        info!(
+            "Inserted {} proposer slashings.",
+            builder.block.body.proposer_slashings.len()
+        );
+
+        // Insert `AttesterSlashing` objects
+        for _ in 0..self.num_attester_slashings {
+            let mut attesters: Vec<u64> = vec![];
+            let mut secret_keys: Vec<&SecretKey> = vec![];
+
+            for _ in 0..self.num_indices_per_slashable_vote {
+                let validator_index = validators_iter.next().expect("Insufficient validators.");
+
+                attesters.push(validator_index);
+                secret_keys.push(&keypairs[validator_index as usize].sk);
+            }
+
+            builder.insert_attester_slashing(&attesters, &secret_keys, &state.fork, spec);
+        }
+        info!(
+            "Inserted {} attester slashings.",
+            builder.block.body.attester_slashings.len()
+        );
+
+        // Insert `Attestation` objects.
+        let all_secret_keys: Vec<&SecretKey> = keypairs.iter().map(|keypair| &keypair.sk).collect();
+        builder
+            .insert_attestations(
+                &state,
+                &all_secret_keys,
+                self.num_attestations as usize,
+                spec,
+            )
+            .unwrap();
+        info!(
+            "Inserted {} attestations.",
+            builder.block.body.attestations.len()
+        );
+
+        // Insert `Deposit` objects.
+        for i in 0..self.num_deposits {
+            builder.insert_deposit(
+                32_000_000_000,
+                state.deposit_index + (i as u64),
+                &state,
+                spec,
+            );
+        }
+        info!("Inserted {} deposits.", builder.block.body.deposits.len());
+
+        // Insert the maximum possible number of `Exit` objects.
+        for _ in 0..self.num_exits {
+            let validator_index = validators_iter.next().expect("Insufficient validators.");
+
+            builder.insert_exit(
+                &state,
+                validator_index,
+                &keypairs[validator_index as usize].sk,
+                spec,
+            );
+        }
+        info!(
+            "Inserted {} exits.",
+            builder.block.body.voluntary_exits.len()
+        );
+
+        // Insert the maximum possible number of `Transfer` objects.
+        for _ in 0..self.num_transfers {
+            let validator_index = validators_iter.next().expect("Insufficient validators.");
+
+            // Manually set the validator to be withdrawn.
+            state.validator_registry[validator_index as usize].withdrawable_epoch =
+                state.previous_epoch(spec);
+
+            builder.insert_transfer(
+                &state,
+                validator_index,
+                validator_index,
+                1,
+                keypairs[validator_index as usize].clone(),
+                spec,
+            );
+        }
+        info!("Inserted {} transfers.", builder.block.body.transfers.len());
+
+        let mut block = self.block_builder.build(&keypair.sk, &state.fork, spec);
+
+        // Set the eth1 data to be different from the state.
+        block.eth1_data.block_hash = Hash256::from_slice(&vec![42; 32]);
+
+        (block, state)
+    }
+}

eth2/state_processing/specs/example.yml

@@ -0,0 +1,347 @@
+title: Sanity tests
+summary: Basic sanity checks from phase 0 spec pythonization. All tests are run with
+  `verify_signatures` as set to False.
+test_suite: beacon_state
+fork: tchaikovsky
+version: v0.5.0
+test_cases:
+- name: test_empty_block_transition
+  config: {SHARD_COUNT: 8, TARGET_COMMITTEE_SIZE: 4, MAX_BALANCE_CHURN_QUOTIENT: 32,
+    MAX_INDICES_PER_SLASHABLE_VOTE: 4096, MAX_EXIT_DEQUEUES_PER_EPOCH: 4, SHUFFLE_ROUND_COUNT: 90,
+    DEPOSIT_CONTRACT_TREE_DEPTH: 32, MIN_DEPOSIT_AMOUNT: 1000000000, MAX_DEPOSIT_AMOUNT: 32000000000,
+    FORK_CHOICE_BALANCE_INCREMENT: 1000000000, EJECTION_BALANCE: 16000000000, GENESIS_FORK_VERSION: 0,
+    GENESIS_SLOT: 4294967296, GENESIS_EPOCH: 536870912, GENESIS_START_SHARD: 0, BLS_WITHDRAWAL_PREFIX_BYTE: 0,
+    SECONDS_PER_SLOT: 6, MIN_ATTESTATION_INCLUSION_DELAY: 2, SLOTS_PER_EPOCH: 8, MIN_SEED_LOOKAHEAD: 1,
+    ACTIVATION_EXIT_DELAY: 4, EPOCHS_PER_ETH1_VOTING_PERIOD: 16, SLOTS_PER_HISTORICAL_ROOT: 64,
+    MIN_VALIDATOR_WITHDRAWABILITY_DELAY: 256, PERSISTENT_COMMITTEE_PERIOD: 2048, LATEST_RANDAO_MIXES_LENGTH: 64,
+    LATEST_ACTIVE_INDEX_ROOTS_LENGTH: 64, LATEST_SLASHED_EXIT_LENGTH: 64, BASE_REWARD_QUOTIENT: 32,
+    WHISTLEBLOWER_REWARD_QUOTIENT: 512, ATTESTATION_INCLUSION_REWARD_QUOTIENT: 8,
+    INACTIVITY_PENALTY_QUOTIENT: 16777216, MIN_PENALTY_QUOTIENT: 32, MAX_PROPOSER_SLASHINGS: 16,
+    MAX_ATTESTER_SLASHINGS: 1, MAX_ATTESTATIONS: 128, MAX_DEPOSITS: 16, MAX_VOLUNTARY_EXITS: 16,
+    MAX_TRANSFERS: 16, DOMAIN_BEACON_BLOCK: 0, DOMAIN_RANDAO: 1, DOMAIN_ATTESTATION: 2,
+    DOMAIN_DEPOSIT: 3, DOMAIN_VOLUNTARY_EXIT: 4, DOMAIN_TRANSFER: 5}
+  verify_signatures: false
+  initial_state:
+    slot: 4294967296
+    genesis_time: 0
+    fork: {previous_version: 0, current_version: 0, epoch: 536870912}
+    validator_registry:
+    - {pubkey: '0x000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000',
+      withdrawal_credentials: '0x2222222222222222222222222222222222222222222222222222222222222222',
+      activation_epoch: 536870912, exit_epoch: 18446744073709551615, withdrawable_epoch: 18446744073709551615,
+      initiated_exit: false, slashed: false}
+    - {pubkey: '0x010000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000',
+      withdrawal_credentials: '0x2222222222222222222222222222222222222222222222222222222222222222',
+      activation_epoch: 536870912, exit_epoch: 18446744073709551615, withdrawable_epoch: 18446744073709551615,
+      initiated_exit: false, slashed: false}
+    - {pubkey: '0x020000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000',
+      withdrawal_credentials: '0x2222222222222222222222222222222222222222222222222222222222222222',
+      activation_epoch: 536870912, exit_epoch: 18446744073709551615, withdrawable_epoch: 18446744073709551615,
+      initiated_exit: false, slashed: false}
+    - {pubkey: '0x030000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000',
+      withdrawal_credentials: '0x2222222222222222222222222222222222222222222222222222222222222222',
+      activation_epoch: 536870912, exit_epoch: 18446744073709551615, withdrawable_epoch: 18446744073709551615,
+      initiated_exit: false, slashed: false}
+    - {pubkey: '0x040000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000',
+      withdrawal_credentials: '0x2222222222222222222222222222222222222222222222222222222222222222',
+      activation_epoch: 536870912, exit_epoch: 18446744073709551615, withdrawable_epoch: 18446744073709551615,
+      initiated_exit: false, slashed: false}
+    - {pubkey: '0x050000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000',
+      withdrawal_credentials: '0x2222222222222222222222222222222222222222222222222222222222222222',
+      activation_epoch: 536870912, exit_epoch: 18446744073709551615, withdrawable_epoch: 18446744073709551615,
+      initiated_exit: false, slashed: false}
+    - {pubkey: '0x060000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000',
+      withdrawal_credentials: '0x2222222222222222222222222222222222222222222222222222222222222222',
+      activation_epoch: 536870912, exit_epoch: 18446744073709551615, withdrawable_epoch: 18446744073709551615,
+      initiated_exit: false, slashed: false}
+    - {pubkey: '0x070000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000',
+      withdrawal_credentials: '0x2222222222222222222222222222222222222222222222222222222222222222',
+      activation_epoch: 536870912, exit_epoch: 18446744073709551615, withdrawable_epoch: 18446744073709551615,
+      initiated_exit: false, slashed: false}
+    - {pubkey: '0x080000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000',
+      withdrawal_credentials: '0x2222222222222222222222222222222222222222222222222222222222222222',
+      activation_epoch: 536870912, exit_epoch: 18446744073709551615, withdrawable_epoch: 18446744073709551615,
+      initiated_exit: false, slashed: false}
+    - {pubkey: '0x090000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000',
+      withdrawal_credentials: '0x2222222222222222222222222222222222222222222222222222222222222222',
+      activation_epoch: 536870912, exit_epoch: 18446744073709551615, withdrawable_epoch: 18446744073709551615,
+      initiated_exit: false, slashed: false}
+    - {pubkey: '0x0a0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000',
+      withdrawal_credentials: '0x2222222222222222222222222222222222222222222222222222222222222222',
+      activation_epoch: 536870912, exit_epoch: 18446744073709551615, withdrawable_epoch: 18446744073709551615,
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eth2/state_processing/src/common/exit_validator.rs

@@ -0,0 +1,22 @@
+use types::{BeaconStateError as Error, *};
+
+/// Exit the validator of the given `index`.
+///
+/// Spec v0.5.0
+pub fn exit_validator(
+    state: &mut BeaconState,
+    validator_index: usize,
+    spec: &ChainSpec,
+) -> Result<(), Error> {
+    if validator_index >= state.validator_registry.len() {
+        return Err(Error::UnknownValidator);
+    }
+
+    let delayed_epoch = state.get_delayed_activation_exit_epoch(state.current_epoch(spec), spec);
+
+    if state.validator_registry[validator_index].exit_epoch > delayed_epoch {
+        state.validator_registry[validator_index].exit_epoch = delayed_epoch;
+    }
+
+    Ok(())
+}

eth2/state_processing/src/common/mod.rs

@@ -0,0 +1,7 @@
+mod exit_validator;
+mod slash_validator;
+mod verify_bitfield;
+
+pub use exit_validator::exit_validator;
+pub use slash_validator::slash_validator;
+pub use verify_bitfield::verify_bitfield_length;

eth2/state_processing/src/common/slash_validator.rs

@@ -0,0 +1,62 @@
+use crate::common::exit_validator;
+use types::{BeaconStateError as Error, *};
+
+/// Slash the validator with index ``index``.
+///
+/// Spec v0.5.0
+pub fn slash_validator(
+    state: &mut BeaconState,
+    validator_index: usize,
+    spec: &ChainSpec,
+) -> Result<(), Error> {
+    let current_epoch = state.current_epoch(spec);
+
+    if (validator_index >= state.validator_registry.len())
+        | (validator_index >= state.validator_balances.len())
+    {
+        return Err(BeaconStateError::UnknownValidator);
+    }
+
+    let validator = &state.validator_registry[validator_index];
+
+    let effective_balance = state.get_effective_balance(validator_index, spec)?;
+
+    // A validator that is withdrawn cannot be slashed.
+    //
+    // This constraint will be lifted in Phase 0.
+    if state.slot
+        >= validator
+            .withdrawable_epoch
+            .start_slot(spec.slots_per_epoch)
+    {
+        return Err(Error::ValidatorIsWithdrawable);
+    }
+
+    exit_validator(state, validator_index, spec)?;
+
+    state.set_slashed_balance(
+        current_epoch,
+        state.get_slashed_balance(current_epoch, spec)? + effective_balance,
+        spec,
+    )?;
+
+    let whistleblower_index =
+        state.get_beacon_proposer_index(state.slot, RelativeEpoch::Current, spec)?;
+    let whistleblower_reward = effective_balance / spec.whistleblower_reward_quotient;
+
+    safe_add_assign!(
+        state.validator_balances[whistleblower_index as usize],
+        whistleblower_reward
+    );
+    safe_sub_assign!(
+        state.validator_balances[validator_index],
+        whistleblower_reward
+    );
+
+    state.validator_registry[validator_index].slashed = true;
+
+    state.validator_registry[validator_index].withdrawable_epoch =
+        current_epoch + Epoch::from(spec.latest_slashed_exit_length);
+
+    Ok(())
+}

eth2/state_processing/src/common/verify_bitfield.rs

@@ -1,10 +1,10 @@
-use crate::*;
+use types::*;
 
 /// Verify ``bitfield`` against the ``committee_size``.
 ///
 /// Is title `verify_bitfield` in spec.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 pub fn verify_bitfield_length(bitfield: &Bitfield, committee_size: usize) -> bool {
     if bitfield.num_bytes() != ((committee_size + 7) / 8) {
         return false;

eth2/state_processing/src/get_genesis_state.rs

@@ -0,0 +1,58 @@
+use super::per_block_processing::{errors::BlockProcessingError, process_deposits};
+use ssz::TreeHash;
+use types::*;
+
+pub enum GenesisError {
+    BlockProcessingError(BlockProcessingError),
+    BeaconStateError(BeaconStateError),
+}
+
+/// Returns the genesis `BeaconState`
+///
+/// Spec v0.5.0
+pub fn get_genesis_state(
+    genesis_validator_deposits: &[Deposit],
+    genesis_time: u64,
+    genesis_eth1_data: Eth1Data,
+    spec: &ChainSpec,
+) -> Result<(), BlockProcessingError> {
+    // Get the genesis `BeaconState`
+    let mut state = BeaconState::genesis(genesis_time, genesis_eth1_data, spec);
+
+    // Process genesis deposits.
+    process_deposits(&mut state, genesis_validator_deposits, spec)?;
+
+    // Process genesis activations.
+    for i in 0..state.validator_registry.len() {
+        if state.get_effective_balance(i, spec)? >= spec.max_deposit_amount {
+            state.validator_registry[i].activation_epoch = spec.genesis_epoch;
+        }
+    }
+
+    // Ensure the current epoch cache is built.
+    state.build_epoch_cache(RelativeEpoch::Current, spec)?;
+
+    // Set all the active index roots to be the genesis active index root.
+    let active_validator_indices = state
+        .get_cached_active_validator_indices(RelativeEpoch::Current, spec)?
+        .to_vec();
+    let genesis_active_index_root = Hash256::from_slice(&active_validator_indices.hash_tree_root());
+    state.fill_active_index_roots_with(genesis_active_index_root, spec);
+
+    // Generate the current shuffling seed.
+    state.current_shuffling_seed = state.generate_seed(spec.genesis_epoch, spec)?;
+
+    Ok(())
+}
+
+impl From<BlockProcessingError> for GenesisError {
+    fn from(e: BlockProcessingError) -> GenesisError {
+        GenesisError::BlockProcessingError(e)
+    }
+}
+
+impl From<BeaconStateError> for GenesisError {
+    fn from(e: BeaconStateError) -> GenesisError {
+        GenesisError::BeaconStateError(e)
+    }
+}

eth2/state_processing/src/lib.rs

@@ -1,10 +1,13 @@
 #[macro_use]
 mod macros;
 
+pub mod common;
+pub mod get_genesis_state;
 pub mod per_block_processing;
 pub mod per_epoch_processing;
 pub mod per_slot_processing;
 
+pub use get_genesis_state::get_genesis_state;
 pub use per_block_processing::{
     errors::{BlockInvalid, BlockProcessingError},
     per_block_processing, per_block_processing_without_verifying_block_signature,

eth2/state_processing/src/per_block_processing.rs

@@ -1,17 +1,15 @@
 use self::verify_proposer_slashing::verify_proposer_slashing;
+use crate::common::slash_validator;
 use errors::{BlockInvalid as Invalid, BlockProcessingError as Error, IntoWithIndex};
-use hashing::hash;
 use rayon::prelude::*;
-use ssz::{ssz_encode, SignedRoot, TreeHash};
+use ssz::{SignedRoot, TreeHash};
 use types::*;
 
 pub use self::verify_attester_slashing::{
     gather_attester_slashing_indices, verify_attester_slashing,
 };
 pub use validate_attestation::{validate_attestation, validate_attestation_without_signature};
-pub use verify_deposit::{
+pub use verify_deposit::{get_existing_validator_index, verify_deposit, verify_deposit_index};
-    build_public_key_hashmap, get_existing_validator_index, verify_deposit, verify_deposit_index,
-};
 pub use verify_exit::verify_exit;
 pub use verify_slashable_attestation::verify_slashable_attestation;
 pub use verify_transfer::{execute_transfer, verify_transfer};
@@ -35,7 +33,7 @@ const VERIFY_DEPOSIT_MERKLE_PROOFS: bool = false;
 /// Returns `Ok(())` if the block is valid and the state was successfully updated. Otherwise
 /// returns an error describing why the block was invalid or how the function failed to execute.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 pub fn per_block_processing(
     state: &mut BeaconState,
     block: &BeaconBlock,
@@ -50,7 +48,7 @@ pub fn per_block_processing(
 /// Returns `Ok(())` if the block is valid and the state was successfully updated. Otherwise
 /// returns an error describing why the block was invalid or how the function failed to execute.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 pub fn per_block_processing_without_verifying_block_signature(
     state: &mut BeaconState,
     block: &BeaconBlock,
@@ -65,25 +63,24 @@ pub fn per_block_processing_without_verifying_block_signature(
 /// Returns `Ok(())` if the block is valid and the state was successfully updated. Otherwise
 /// returns an error describing why the block was invalid or how the function failed to execute.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 fn per_block_processing_signature_optional(
     mut state: &mut BeaconState,
     block: &BeaconBlock,
     should_verify_block_signature: bool,
     spec: &ChainSpec,
 ) -> Result<(), Error> {
-    // Verify that `block.slot == state.slot`.
+    process_block_header(state, block, spec)?;
-    verify!(block.slot == state.slot, Invalid::StateSlotMismatch);
 
     // Ensure the current and previous epoch cache is built.
-    state.build_epoch_cache(RelativeEpoch::Current, spec)?;
     state.build_epoch_cache(RelativeEpoch::Previous, spec)?;
+    state.build_epoch_cache(RelativeEpoch::Current, spec)?;
 
     if should_verify_block_signature {
         verify_block_signature(&state, &block, &spec)?;
     }
     process_randao(&mut state, &block, &spec)?;
-    process_eth1_data(&mut state, &block.eth1_data)?;
+    process_eth1_data(&mut state, &block.body.eth1_data)?;
     process_proposer_slashings(&mut state, &block.body.proposer_slashings, spec)?;
     process_attester_slashings(&mut state, &block.body.attester_slashings, spec)?;
     process_attestations(&mut state, &block.body.attestations, spec)?;
@@ -94,33 +91,50 @@ fn per_block_processing_signature_optional(
     Ok(())
 }
 
+/// Processes the block header.
+///
+/// Spec v0.5.0
+pub fn process_block_header(
+    state: &mut BeaconState,
+    block: &BeaconBlock,
+    spec: &ChainSpec,
+) -> Result<(), Error> {
+    verify!(block.slot == state.slot, Invalid::StateSlotMismatch);
+
+    // NOTE: this is not to spec. I think spec is broken. See:
+    //
+    // https://github.com/ethereum/eth2.0-specs/issues/797
+    verify!(
+        block.previous_block_root == *state.get_block_root(state.slot - 1, spec)?,
+        Invalid::ParentBlockRootMismatch
+    );
+
+    state.latest_block_header = block.temporary_block_header(spec);
+
+    Ok(())
+}
+
 /// Verifies the signature of a block.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 pub fn verify_block_signature(
     state: &BeaconState,
     block: &BeaconBlock,
     spec: &ChainSpec,
 ) -> Result<(), Error> {
-    let block_proposer =
+    let block_proposer = &state.validator_registry
-        &state.validator_registry[state.get_beacon_proposer_index(block.slot, spec)?];
+        [state.get_beacon_proposer_index(block.slot, RelativeEpoch::Current, spec)?];
 
-    let proposal = Proposal {
-        slot: block.slot,
-        shard: spec.beacon_chain_shard_number,
-        block_root: Hash256::from_slice(&block.signed_root()[..]),
-        signature: block.signature.clone(),
-    };
     let domain = spec.get_domain(
         block.slot.epoch(spec.slots_per_epoch),
-        Domain::Proposal,
+        Domain::BeaconBlock,
         &state.fork,
     );
 
     verify!(
-        proposal
+        block
             .signature
-            .verify(&proposal.signed_root()[..], domain, &block_proposer.pubkey),
+            .verify(&block.signed_root()[..], domain, &block_proposer.pubkey),
         Invalid::BadSignature
     );
 
@@ -130,21 +144,18 @@ pub fn verify_block_signature(
 /// Verifies the `randao_reveal` against the block's proposer pubkey and updates
 /// `state.latest_randao_mixes`.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 pub fn process_randao(
     state: &mut BeaconState,
     block: &BeaconBlock,
     spec: &ChainSpec,
 ) -> Result<(), Error> {
-    // Let `proposer = state.validator_registry[get_beacon_proposer_index(state, state.slot)]`.
+    let block_proposer = &state.validator_registry
-    let block_proposer =
+        [state.get_beacon_proposer_index(block.slot, RelativeEpoch::Current, spec)?];
-        &state.validator_registry[state.get_beacon_proposer_index(block.slot, spec)?];
 
-    // Verify that `bls_verify(pubkey=proposer.pubkey,
+    // Verify the RANDAO is a valid signature of the proposer.
-    // message_hash=hash_tree_root(get_current_epoch(state)), signature=block.randao_reveal,
-    // domain=get_domain(state.fork, get_current_epoch(state), DOMAIN_RANDAO))`.
     verify!(
-        block.randao_reveal.verify(
+        block.body.randao_reveal.verify(
             &state.current_epoch(spec).hash_tree_root()[..],
             spec.get_domain(
                 block.slot.epoch(spec.slots_per_epoch),
@@ -156,21 +167,23 @@ pub fn process_randao(
         Invalid::BadRandaoSignature
     );
 
-    // Update the state's RANDAO mix with the one revealed in the block.
+    // Update the current epoch RANDAO mix.
-    update_randao(state, &block.randao_reveal, spec)?;
+    state.update_randao_mix(state.current_epoch(spec), &block.body.randao_reveal, spec)?;
 
     Ok(())
 }
 
 /// Update the `state.eth1_data_votes` based upon the `eth1_data` provided.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 pub fn process_eth1_data(state: &mut BeaconState, eth1_data: &Eth1Data) -> Result<(), Error> {
-    // Either increment the eth1_data vote count, or add a new eth1_data.
+    // Attempt to find a `Eth1DataVote` with matching `Eth1Data`.
     let matching_eth1_vote_index = state
         .eth1_data_votes
         .iter()
         .position(|vote| vote.eth1_data == *eth1_data);
+
+    // If a vote exists, increment it's `vote_count`. Otherwise, create a new `Eth1DataVote`.
     if let Some(index) = matching_eth1_vote_index {
         state.eth1_data_votes[index].vote_count += 1;
     } else {
@@ -183,46 +196,12 @@ pub fn process_eth1_data(state: &mut BeaconState, eth1_data: &Eth1Data) -> Resul
     Ok(())
 }
 
-/// Updates the present randao mix.
-///
-/// Set `state.latest_randao_mixes[get_current_epoch(state) % LATEST_RANDAO_MIXES_LENGTH] =
-/// xor(get_randao_mix(state, get_current_epoch(state)), hash(block.randao_reveal))`.
-///
-/// Spec v0.4.0
-pub fn update_randao(
-    state: &mut BeaconState,
-    reveal: &Signature,
-    spec: &ChainSpec,
-) -> Result<(), BeaconStateError> {
-    let hashed_reveal = {
-        let encoded_signature = ssz_encode(reveal);
-        Hash256::from_slice(&hash(&encoded_signature[..])[..])
-    };
-
-    let current_epoch = state.slot.epoch(spec.slots_per_epoch);
-
-    let current_mix = state
-        .get_randao_mix(current_epoch, spec)
-        .ok_or_else(|| BeaconStateError::InsufficientRandaoMixes)?;
-
-    let new_mix = *current_mix ^ hashed_reveal;
-
-    let index = current_epoch.as_usize() % spec.latest_randao_mixes_length;
-
-    if index < state.latest_randao_mixes.len() {
-        state.latest_randao_mixes[index] = new_mix;
-        Ok(())
-    } else {
-        Err(BeaconStateError::InsufficientRandaoMixes)
-    }
-}
-
 /// Validates each `ProposerSlashing` and updates the state, short-circuiting on an invalid object.
 ///
 /// Returns `Ok(())` if the validation and state updates completed successfully, otherwise returns
 /// an `Err` describing the invalid object or cause of failure.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 pub fn process_proposer_slashings(
     state: &mut BeaconState,
     proposer_slashings: &[ProposerSlashing],
@@ -242,8 +221,9 @@ pub fn process_proposer_slashings(
                 .map_err(|e| e.into_with_index(i))
         })?;
 
+    // Update the state.
     for proposer_slashing in proposer_slashings {
-        state.slash_validator(proposer_slashing.proposer_index as usize, spec)?;
+        slash_validator(state, proposer_slashing.proposer_index as usize, spec)?;
     }
 
     Ok(())
@@ -254,7 +234,7 @@ pub fn process_proposer_slashings(
 /// Returns `Ok(())` if the validation and state updates completed successfully, otherwise returns
 /// an `Err` describing the invalid object or cause of failure.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 pub fn process_attester_slashings(
     state: &mut BeaconState,
     attester_slashings: &[AttesterSlashing],
@@ -296,11 +276,11 @@ pub fn process_attester_slashings(
         )
         .map_err(|e| e.into_with_index(i))?;
 
-        let slashable_indices = gather_attester_slashing_indices(&state, &attester_slashing)
+        let slashable_indices = gather_attester_slashing_indices(&state, &attester_slashing, spec)
             .map_err(|e| e.into_with_index(i))?;
 
         for i in slashable_indices {
-            state.slash_validator(i as usize, spec)?;
+            slash_validator(state, i as usize, spec)?;
         }
     }
 
@@ -312,7 +292,7 @@ pub fn process_attester_slashings(
 /// Returns `Ok(())` if the validation and state updates completed successfully, otherwise returns
 /// an `Err` describing the invalid object or cause of failure.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 pub fn process_attestations(
     state: &mut BeaconState,
     attestations: &[Attestation],
@@ -342,7 +322,14 @@ pub fn process_attestations(
             custody_bitfield: attestation.custody_bitfield.clone(),
             inclusion_slot: state.slot,
         };
-        state.latest_attestations.push(pending_attestation);
+
+        let attestation_epoch = attestation.data.slot.epoch(spec.slots_per_epoch);
+
+        if attestation_epoch == state.current_epoch(spec) {
+            state.current_epoch_attestations.push(pending_attestation)
+        } else if attestation_epoch == state.previous_epoch(spec) {
+            state.previous_epoch_attestations.push(pending_attestation)
+        }
     }
 
     Ok(())
@@ -353,7 +340,7 @@ pub fn process_attestations(
 /// Returns `Ok(())` if the validation and state updates completed successfully, otherwise returns
 /// an `Err` describing the invalid object or cause of failure.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 pub fn process_deposits(
     state: &mut BeaconState,
     deposits: &[Deposit],
@@ -401,7 +388,7 @@ pub fn process_deposits(
             // Create a new validator.
             let validator = Validator {
                 pubkey: deposit_input.pubkey.clone(),
-                withdrawal_credentials: deposit_input.withdrawal_credentials.clone(),
+                withdrawal_credentials: deposit_input.withdrawal_credentials,
                 activation_epoch: spec.far_future_epoch,
                 exit_epoch: spec.far_future_epoch,
                 withdrawable_epoch: spec.far_future_epoch,
@@ -423,7 +410,7 @@ pub fn process_deposits(
 /// Returns `Ok(())` if the validation and state updates completed successfully, otherwise returns
 /// an `Err` describing the invalid object or cause of failure.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 pub fn process_exits(
     state: &mut BeaconState,
     voluntary_exits: &[VoluntaryExit],
@@ -455,7 +442,7 @@ pub fn process_exits(
 /// Returns `Ok(())` if the validation and state updates completed successfully, otherwise returns
 /// an `Err` describing the invalid object or cause of failure.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 pub fn process_transfers(
     state: &mut BeaconState,
     transfers: &[Transfer],

eth2/state_processing/src/per_block_processing/errors.rs

@@ -67,6 +67,7 @@ impl_from_beacon_state_error!(BlockProcessingError);
 #[derive(Debug, PartialEq)]
 pub enum BlockInvalid {
     StateSlotMismatch,
+    ParentBlockRootMismatch,
     BadSignature,
     BadRandaoSignature,
     MaxAttestationsExceeded,
@@ -112,45 +113,53 @@ pub enum AttestationValidationError {
 #[derive(Debug, PartialEq)]
 pub enum AttestationInvalid {
     /// Attestation references a pre-genesis slot.
-    ///
+    PreGenesis { genesis: Slot, attestation: Slot },
-    /// (genesis_slot, attestation_slot)
-    PreGenesis(Slot, Slot),
     /// Attestation included before the inclusion delay.
-    ///
+    IncludedTooEarly {
-    /// (state_slot, inclusion_delay, attestation_slot)
+        state: Slot,
-    IncludedTooEarly(Slot, u64, Slot),
+        delay: u64,
+        attestation: Slot,
+    },
     /// Attestation slot is too far in the past to be included in a block.
-    ///
+    IncludedTooLate { state: Slot, attestation: Slot },
-    /// (state_slot, attestation_slot)
-    IncludedTooLate(Slot, Slot),
     /// Attestation justified epoch does not match the states current or previous justified epoch.
     ///
-    /// (attestation_justified_epoch, state_epoch, used_previous_epoch)
+    /// `is_current` is `true` if the attestation was compared to the
-    WrongJustifiedEpoch(Epoch, Epoch, bool),
+    /// `state.current_justified_epoch`, `false` if compared to `state.previous_justified_epoch`.
+    WrongJustifiedEpoch {
+        state: Epoch,
+        attestation: Epoch,
+        is_current: bool,
+    },
     /// Attestation justified epoch root does not match root known to the state.
     ///
-    /// (state_justified_root, attestation_justified_root)
+    /// `is_current` is `true` if the attestation was compared to the
-    WrongJustifiedRoot(Hash256, Hash256),
+    /// `state.current_justified_epoch`, `false` if compared to `state.previous_justified_epoch`.
+    WrongJustifiedRoot {
+        state: Hash256,
+        attestation: Hash256,
+        is_current: bool,
+    },
     /// Attestation crosslink root does not match the state crosslink root for the attestations
     /// slot.
-    BadLatestCrosslinkRoot,
+    BadPreviousCrosslink,
     /// The custody bitfield has some bits set `true`. This is not allowed in phase 0.
     CustodyBitfieldHasSetBits,
     /// There are no set bits on the attestation -- an attestation must be signed by at least one
     /// validator.
     AggregationBitfieldIsEmpty,
     /// The custody bitfield length is not the smallest possible size to represent the committee.
-    ///
+    BadCustodyBitfieldLength {
-    /// (committee_len, bitfield_len)
+        committee_len: usize,
-    BadCustodyBitfieldLength(usize, usize),
+        bitfield_len: usize,
+    },
     /// The aggregation bitfield length is not the smallest possible size to represent the committee.
-    ///
+    BadAggregationBitfieldLength {
-    /// (committee_len, bitfield_len)
+        committee_len: usize,
-    BadAggregationBitfieldLength(usize, usize),
+        bitfield_len: usize,
-    /// There was no known committee for the given shard in the given slot.
+    },
-    ///
+    /// There was no known committee in this `epoch` for the given shard and slot.
-    /// (attestation_data_shard, attestation_data_slot)
+    NoCommitteeForShard { shard: u64, slot: Slot },
-    NoCommitteeForShard(u64, Slot),
     /// The validator index was unknown.
     UnknownValidator(u64),
     /// The attestation signature verification failed.
@@ -188,6 +197,8 @@ pub enum AttesterSlashingInvalid {
     SlashableAttestation2Invalid(SlashableAttestationInvalid),
     /// The validator index is unknown. One cannot slash one who does not exist.
     UnknownValidator(u64),
+    /// The specified validator has already been withdrawn.
+    ValidatorAlreadyWithdrawn(u64),
     /// There were no indices able to be slashed.
     NoSlashableIndices,
 }
@@ -264,16 +275,12 @@ pub enum ProposerSlashingInvalid {
     ///
     /// (proposal_1_slot, proposal_2_slot)
     ProposalSlotMismatch(Slot, Slot),
-    /// The two proposal have different shards.
+    /// The proposals are identical and therefore not slashable.
-    ///
+    ProposalsIdentical,
-    /// (proposal_1_shard, proposal_2_shard)
-    ProposalShardMismatch(u64, u64),
-    /// The two proposal have different block roots.
-    ///
-    /// (proposal_1_root, proposal_2_root)
-    ProposalBlockRootMismatch(Hash256, Hash256),
     /// The specified proposer has already been slashed.
     ProposerAlreadySlashed,
+    /// The specified proposer has already been withdrawn.
+    ProposerAlreadyWithdrawn(u64),
     /// The first proposal signature was invalid.
     BadProposal1Signature,
     /// The second proposal signature was invalid.
@@ -302,9 +309,7 @@ pub enum DepositValidationError {
 #[derive(Debug, PartialEq)]
 pub enum DepositInvalid {
     /// The deposit index does not match the state index.
-    ///
+    BadIndex { state: u64, deposit: u64 },
-    /// (state_index, deposit_index)
-    BadIndex(u64, u64),
     /// The proof-of-possession does not match the given pubkey.
     BadProofOfPossession,
     /// The withdrawal credentials for the depositing validator did not match the withdrawal
@@ -334,11 +339,14 @@ pub enum ExitValidationError {
 pub enum ExitInvalid {
     /// The specified validator is not in the state's validator registry.
     ValidatorUnknown(u64),
-    AlreadyExited,
+    /// The specified validator has a non-maximum exit epoch.
+    AlreadyExited(u64),
+    /// The specified validator has already initiated exit.
+    AlreadyInitiatedExited(u64),
     /// The exit is for a future epoch.
-    ///
+    FutureEpoch { state: Epoch, exit: Epoch },
-    /// (state_epoch, exit_epoch)
+    /// The validator has not been active for long enough.
-    FutureEpoch(Epoch, Epoch),
+    TooYoungToLeave { lifespan: Epoch, expected: u64 },
     /// The exit signature was not signed by the validator.
     BadSignature,
 }

eth2/state_processing/src/per_block_processing/validate_attestation.rs

@@ -1,6 +1,6 @@
 use super::errors::{AttestationInvalid as Invalid, AttestationValidationError as Error};
+use crate::common::verify_bitfield_length;
 use ssz::TreeHash;
-use types::beacon_state::helpers::*;
 use types::*;
 
 /// Indicates if an `Attestation` is valid to be included in a block in the current epoch of the
@@ -8,7 +8,7 @@ use types::*;
 ///
 /// Returns `Ok(())` if the `Attestation` is valid, otherwise indicates the reason for invalidity.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 pub fn validate_attestation(
     state: &BeaconState,
     attestation: &Attestation,
@@ -22,7 +22,7 @@ pub fn validate_attestation(
 ///
 /// Returns `Ok(())` if the `Attestation` is valid, otherwise indicates the reason for invalidity.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 pub fn validate_attestation_without_signature(
     state: &BeaconState,
     attestation: &Attestation,
@@ -35,74 +35,83 @@ pub fn validate_attestation_without_signature(
 /// given state, optionally validating the aggregate signature.
 ///
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 fn validate_attestation_signature_optional(
     state: &BeaconState,
     attestation: &Attestation,
     spec: &ChainSpec,
     verify_signature: bool,
 ) -> Result<(), Error> {
-    // Verify that `attestation.data.slot >= GENESIS_SLOT`.
+    let state_epoch = state.slot.epoch(spec.slots_per_epoch);
+    let attestation_epoch = attestation.data.slot.epoch(spec.slots_per_epoch);
+
+    // Can't submit pre-historic attestations.
     verify!(
         attestation.data.slot >= spec.genesis_slot,
-        Invalid::PreGenesis(spec.genesis_slot, attestation.data.slot)
+        Invalid::PreGenesis {
+            genesis: spec.genesis_slot,
+            attestation: attestation.data.slot
+        }
     );
 
-    // Verify that `attestation.data.slot + MIN_ATTESTATION_INCLUSION_DELAY <= state.slot`.
+    // Can't submit attestations too far in history.
+    verify!(
+        state.slot <= attestation.data.slot + spec.slots_per_epoch,
+        Invalid::IncludedTooLate {
+            state: spec.genesis_slot,
+            attestation: attestation.data.slot
+        }
+    );
+
+    // Can't submit attestation too quickly.
     verify!(
         attestation.data.slot + spec.min_attestation_inclusion_delay <= state.slot,
-        Invalid::IncludedTooEarly(
+        Invalid::IncludedTooEarly {
-            state.slot,
+            state: state.slot,
-            spec.min_attestation_inclusion_delay,
+            delay: spec.min_attestation_inclusion_delay,
-            attestation.data.slot
+            attestation: attestation.data.slot
-        )
+        }
     );
 
-    // Verify that `state.slot < attestation.data.slot + SLOTS_PER_EPOCH`.
+    // Verify the justified epoch and root is correct.
+    if attestation_epoch >= state_epoch {
         verify!(
-        state.slot < attestation.data.slot + spec.slots_per_epoch,
+            attestation.data.source_epoch == state.current_justified_epoch,
-        Invalid::IncludedTooLate(state.slot, attestation.data.slot)
+            Invalid::WrongJustifiedEpoch {
+                state: state.current_justified_epoch,
+                attestation: attestation.data.source_epoch,
+                is_current: true,
+            }
         );
-
-    // Verify that `attestation.data.justified_epoch` is equal to `state.justified_epoch` if
-    // `slot_to_epoch(attestation.data.slot + 1) >= get_current_epoch(state) else
-    // state.previous_justified_epoch`.
-    if (attestation.data.slot + 1).epoch(spec.slots_per_epoch) >= state.current_epoch(spec) {
         verify!(
-            attestation.data.justified_epoch == state.justified_epoch,
+            attestation.data.source_root == state.current_justified_root,
-            Invalid::WrongJustifiedEpoch(
+            Invalid::WrongJustifiedRoot {
-                attestation.data.justified_epoch,
+                state: state.current_justified_root,
-                state.justified_epoch,
+                attestation: attestation.data.source_root,
-                false
+                is_current: true,
-            )
+            }
         );
     } else {
         verify!(
-            attestation.data.justified_epoch == state.previous_justified_epoch,
+            attestation.data.source_epoch == state.previous_justified_epoch,
-            Invalid::WrongJustifiedEpoch(
+            Invalid::WrongJustifiedEpoch {
-                attestation.data.justified_epoch,
+                state: state.previous_justified_epoch,
-                state.previous_justified_epoch,
+                attestation: attestation.data.source_epoch,
-                true
+                is_current: false,
-            )
+            }
+        );
+        verify!(
+            attestation.data.source_root == state.previous_justified_root,
+            Invalid::WrongJustifiedRoot {
+                state: state.previous_justified_root,
+                attestation: attestation.data.source_root,
+                is_current: true,
+            }
         );
     }
 
-    // Verify that `attestation.data.justified_block_root` is equal to `get_block_root(state,
+    // Check that the crosslink data is valid.
-    // get_epoch_start_slot(attestation.data.justified_epoch))`.
+    //
-    let justified_block_root = *state
-        .get_block_root(
-            attestation
-                .data
-                .justified_epoch
-                .start_slot(spec.slots_per_epoch),
-            &spec,
-        )
-        .ok_or(BeaconStateError::InsufficientBlockRoots)?;
-    verify!(
-        attestation.data.justified_block_root == justified_block_root,
-        Invalid::WrongJustifiedRoot(justified_block_root, attestation.data.justified_block_root)
-    );
-
     // Verify that either:
     //
     // (i)`state.latest_crosslinks[attestation.data.shard] == attestation.data.latest_crosslink`,
@@ -115,63 +124,62 @@ fn validate_attestation_signature_optional(
         epoch: attestation.data.slot.epoch(spec.slots_per_epoch),
     };
     verify!(
-        (attestation.data.latest_crosslink
+        (attestation.data.previous_crosslink
             == state.latest_crosslinks[attestation.data.shard as usize])
             | (state.latest_crosslinks[attestation.data.shard as usize] == potential_crosslink),
-        Invalid::BadLatestCrosslinkRoot
+        Invalid::BadPreviousCrosslink
     );
 
-    // Get the committee for this attestation
+    // Attestation must be non-empty!
-    let (committee, _shard) = state
-        .get_crosslink_committees_at_slot(attestation.data.slot, spec)?
-        .iter()
-        .find(|(_committee, shard)| *shard == attestation.data.shard)
-        .ok_or_else(|| {
-            Error::Invalid(Invalid::NoCommitteeForShard(
-                attestation.data.shard,
-                attestation.data.slot,
-            ))
-        })?;
-
-    // Custody bitfield is all zeros (phase 0 requirement).
-    verify!(
-        attestation.custody_bitfield.num_set_bits() == 0,
-        Invalid::CustodyBitfieldHasSetBits
-    );
-    // Custody bitfield length is correct.
-    verify!(
-        verify_bitfield_length(&attestation.custody_bitfield, committee.len()),
-        Invalid::BadCustodyBitfieldLength(committee.len(), attestation.custody_bitfield.len())
-    );
-    // Aggregation bitfield isn't empty.
     verify!(
         attestation.aggregation_bitfield.num_set_bits() != 0,
         Invalid::AggregationBitfieldIsEmpty
     );
+    // Custody bitfield must be empty (be be removed in phase 1)
+    verify!(
+        attestation.custody_bitfield.num_set_bits() == 0,
+        Invalid::CustodyBitfieldHasSetBits
+    );
+
+    // Get the committee for the specific shard that this attestation is for.
+    let crosslink_committee = state
+        .get_crosslink_committees_at_slot(attestation.data.slot, spec)?
+        .iter()
+        .find(|c| c.shard == attestation.data.shard)
+        .ok_or_else(|| {
+            Error::Invalid(Invalid::NoCommitteeForShard {
+                shard: attestation.data.shard,
+                slot: attestation.data.slot,
+            })
+        })?;
+    let committee = &crosslink_committee.committee;
+
+    // Custody bitfield length is correct.
+    //
+    // This is not directly in the spec, but it is inferred.
+    verify!(
+        verify_bitfield_length(&attestation.custody_bitfield, committee.len()),
+        Invalid::BadCustodyBitfieldLength {
+            committee_len: committee.len(),
+            bitfield_len: attestation.custody_bitfield.len()
+        }
+    );
     // Aggregation bitfield length is correct.
+    //
+    // This is not directly in the spec, but it is inferred.
     verify!(
         verify_bitfield_length(&attestation.aggregation_bitfield, committee.len()),
-        Invalid::BadAggregationBitfieldLength(
+        Invalid::BadAggregationBitfieldLength {
-            committee.len(),
+            committee_len: committee.len(),
-            attestation.aggregation_bitfield.len()
+            bitfield_len: attestation.custody_bitfield.len()
-        )
+        }
     );
 
     if verify_signature {
-        let attestation_epoch = attestation.data.slot.epoch(spec.slots_per_epoch);
+        verify_attestation_signature(state, committee, attestation, spec)?;
-        verify_attestation_signature(
-            state,
-            committee,
-            attestation_epoch,
-            &attestation.aggregation_bitfield,
-            &attestation.custody_bitfield,
-            &attestation.data,
-            &attestation.aggregate_signature,
-            spec,
-        )?;
     }
 
-    // [TO BE REMOVED IN PHASE 1] Verify that `attestation.data.crosslink_data_root == ZERO_HASH`.
+    // Crosslink data root is zero (to be removed in phase 1).
     verify!(
         attestation.data.crosslink_data_root == spec.zero_hash,
         Invalid::ShardBlockRootNotZero
@@ -188,37 +196,34 @@ fn validate_attestation_signature_optional(
 ///  - `custody_bitfield` does not have a bit for each index of `committee`.
 ///  - A `validator_index` in `committee` is not in `state.validator_registry`.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 fn verify_attestation_signature(
     state: &BeaconState,
     committee: &[usize],
-    attestation_epoch: Epoch,
+    a: &Attestation,
-    aggregation_bitfield: &Bitfield,
-    custody_bitfield: &Bitfield,
-    attestation_data: &AttestationData,
-    aggregate_signature: &AggregateSignature,
     spec: &ChainSpec,
 ) -> Result<(), Error> {
     let mut aggregate_pubs = vec![AggregatePublicKey::new(); 2];
     let mut message_exists = vec![false; 2];
+    let attestation_epoch = a.data.slot.epoch(spec.slots_per_epoch);
 
     for (i, v) in committee.iter().enumerate() {
-        let validator_signed = aggregation_bitfield.get(i).map_err(|_| {
+        let validator_signed = a.aggregation_bitfield.get(i).map_err(|_| {
-            Error::Invalid(Invalid::BadAggregationBitfieldLength(
+            Error::Invalid(Invalid::BadAggregationBitfieldLength {
-                committee.len(),
+                committee_len: committee.len(),
-                aggregation_bitfield.len(),
+                bitfield_len: a.aggregation_bitfield.len(),
-            ))
+            })
         })?;
 
         if validator_signed {
-            let custody_bit: bool = match custody_bitfield.get(i) {
+            let custody_bit: bool = match a.custody_bitfield.get(i) {
                 Ok(bit) => bit,
                 // Invalidate signature if custody_bitfield.len() < committee
                 Err(_) => {
-                    return Err(Error::Invalid(Invalid::BadCustodyBitfieldLength(
+                    return Err(Error::Invalid(Invalid::BadCustodyBitfieldLength {
-                        committee.len(),
+                        committee_len: committee.len(),
-                        custody_bitfield.len(),
+                        bitfield_len: a.aggregation_bitfield.len(),
-                    )));
+                    }));
                 }
             };
 
@@ -236,14 +241,14 @@ fn verify_attestation_signature(
 
     // Message when custody bitfield is `false`
     let message_0 = AttestationDataAndCustodyBit {
-        data: attestation_data.clone(),
+        data: a.data.clone(),
         custody_bit: false,
     }
     .hash_tree_root();
 
     // Message when custody bitfield is `true`
     let message_1 = AttestationDataAndCustodyBit {
-        data: attestation_data.clone(),
+        data: a.data.clone(),
         custody_bit: true,
     }
     .hash_tree_root();
@@ -265,7 +270,8 @@ fn verify_attestation_signature(
     let domain = spec.get_domain(attestation_epoch, Domain::Attestation, &state.fork);
 
     verify!(
-        aggregate_signature.verify_multiple(&messages[..], domain, &keys[..]),
+        a.aggregate_signature
+            .verify_multiple(&messages[..], domain, &keys[..]),
         Invalid::BadSignature
     );
 

eth2/state_processing/src/per_block_processing/verify_attester_slashing.rs

@@ -7,7 +7,7 @@ use types::*;
 ///
 /// Returns `Ok(())` if the `AttesterSlashing` is valid, otherwise indicates the reason for invalidity.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 pub fn verify_attester_slashing(
     state: &BeaconState,
     attester_slashing: &AttesterSlashing,
@@ -41,15 +41,16 @@ pub fn verify_attester_slashing(
 ///
 /// Returns Ok(indices) if `indices.len() > 0`.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 pub fn gather_attester_slashing_indices(
     state: &BeaconState,
     attester_slashing: &AttesterSlashing,
+    spec: &ChainSpec,
 ) -> Result<Vec<u64>, Error> {
     let slashable_attestation_1 = &attester_slashing.slashable_attestation_1;
     let slashable_attestation_2 = &attester_slashing.slashable_attestation_2;
 
-    let mut slashable_indices = vec![];
+    let mut slashable_indices = Vec::with_capacity(spec.max_indices_per_slashable_vote);
     for i in &slashable_attestation_1.validator_indices {
         let validator = state
             .validator_registry
@@ -57,11 +58,20 @@ pub fn gather_attester_slashing_indices(
             .ok_or_else(|| Error::Invalid(Invalid::UnknownValidator(*i)))?;
 
         if slashable_attestation_2.validator_indices.contains(&i) & !validator.slashed {
+            // TODO: verify that we should reject any slashable attestation which includes a
+            // withdrawn validator. PH has asked the question on gitter, awaiting response.
+            verify!(
+                validator.withdrawable_epoch > state.slot.epoch(spec.slots_per_epoch),
+                Invalid::ValidatorAlreadyWithdrawn(*i)
+            );
+
             slashable_indices.push(*i);
         }
     }
 
     verify!(!slashable_indices.is_empty(), Invalid::NoSlashableIndices);
 
+    slashable_indices.shrink_to_fit();
+
     Ok(slashable_indices)
 }

eth2/state_processing/src/per_block_processing/verify_deposit.rs

@@ -3,11 +3,8 @@ use hashing::hash;
 use merkle_proof::verify_merkle_proof;
 use ssz::ssz_encode;
 use ssz_derive::Encode;
-use std::collections::HashMap;
 use types::*;
 
-pub type PublicKeyValidatorIndexHashmap = HashMap<PublicKey, u64>;
-
 /// Indicates if a `Deposit` is valid to be included in a block in the current epoch of the given
 /// state.
 ///
@@ -18,7 +15,7 @@ pub type PublicKeyValidatorIndexHashmap = HashMap<PublicKey, u64>;
 ///
 /// Note: this function is incomplete.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 pub fn verify_deposit(
     state: &BeaconState,
     deposit: &Deposit,
@@ -49,35 +46,32 @@ pub fn verify_deposit(
 
 /// Verify that the `Deposit` index is correct.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 pub fn verify_deposit_index(state: &BeaconState, deposit: &Deposit) -> Result<(), Error> {
     verify!(
         deposit.index == state.deposit_index,
-        Invalid::BadIndex(state.deposit_index, deposit.index)
+        Invalid::BadIndex {
+            state: state.deposit_index,
+            deposit: deposit.index
+        }
     );
 
     Ok(())
 }
 
-pub fn build_public_key_hashmap(state: &BeaconState) -> PublicKeyValidatorIndexHashmap {
+/// Returns a `Some(validator index)` if a pubkey already exists in the `validator_registry`,
-    let mut hashmap = HashMap::with_capacity(state.validator_registry.len());
+/// otherwise returns `None`.
-
+///
-    for (i, validator) in state.validator_registry.iter().enumerate() {
+/// ## Errors
-        hashmap.insert(validator.pubkey.clone(), i as u64);
+///
-    }
+/// Errors if the state's `pubkey_cache` is not current.
-
-    hashmap
-}
-
 pub fn get_existing_validator_index(
     state: &BeaconState,
     deposit: &Deposit,
 ) -> Result<Option<u64>, Error> {
     let deposit_input = &deposit.deposit_data.deposit_input;
 
-    let validator_index = state
+    let validator_index = state.get_validator_index(&deposit_input.pubkey)?;
-        .get_validator_index(&deposit_input.pubkey)?
-        .and_then(|i| Some(i));
 
     match validator_index {
         None => Ok(None),
@@ -94,12 +88,12 @@ pub fn get_existing_validator_index(
 
 /// Verify that a deposit is included in the state's eth1 deposit root.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 fn verify_deposit_merkle_proof(state: &BeaconState, deposit: &Deposit, spec: &ChainSpec) -> bool {
     let leaf = hash(&get_serialized_deposit_data(deposit));
     verify_merkle_proof(
         Hash256::from_slice(&leaf),
-        &deposit.branch,
+        &deposit.proof,
         spec.deposit_contract_tree_depth as usize,
         deposit.index as usize,
         state.latest_eth1_data.deposit_root,
@@ -108,7 +102,7 @@ fn verify_deposit_merkle_proof(state: &BeaconState, deposit: &Deposit, spec: &Ch
 
 /// Helper struct for easily getting the serialized data generated by the deposit contract.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 #[derive(Encode)]
 struct SerializedDepositData {
     amount: u64,
@@ -119,7 +113,7 @@ struct SerializedDepositData {
 /// Return the serialized data generated by the deposit contract that is used to generate the
 /// merkle proof.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 fn get_serialized_deposit_data(deposit: &Deposit) -> Vec<u8> {
     let serialized_deposit_data = SerializedDepositData {
         amount: deposit.deposit_data.amount,

eth2/state_processing/src/per_block_processing/verify_exit.rs

@@ -7,7 +7,7 @@ use types::*;
 ///
 /// Returns `Ok(())` if the `Exit` is valid, otherwise indicates the reason for invalidity.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 pub fn verify_exit(
     state: &BeaconState,
     exit: &VoluntaryExit,
@@ -18,15 +18,35 @@ pub fn verify_exit(
         .get(exit.validator_index as usize)
         .ok_or_else(|| Error::Invalid(Invalid::ValidatorUnknown(exit.validator_index)))?;
 
+    // Verify that the validator has not yet exited.
     verify!(
-        validator.exit_epoch
+        validator.exit_epoch == spec.far_future_epoch,
-            > state.get_delayed_activation_exit_epoch(state.current_epoch(spec), spec),
+        Invalid::AlreadyExited(exit.validator_index)
-        Invalid::AlreadyExited
     );
 
+    // Verify that the validator has not yet initiated.
+    verify!(
+        !validator.initiated_exit,
+        Invalid::AlreadyInitiatedExited(exit.validator_index)
+    );
+
+    // Exits must specify an epoch when they become valid; they are not valid before then.
     verify!(
         state.current_epoch(spec) >= exit.epoch,
-        Invalid::FutureEpoch(state.current_epoch(spec), exit.epoch)
+        Invalid::FutureEpoch {
+            state: state.current_epoch(spec),
+            exit: exit.epoch
+        }
+    );
+
+    // Must have been in the validator set long enough.
+    let lifespan = state.slot.epoch(spec.slots_per_epoch) - validator.activation_epoch;
+    verify!(
+        lifespan >= spec.persistent_committee_period,
+        Invalid::TooYoungToLeave {
+            lifespan,
+            expected: spec.persistent_committee_period,
+        }
     );
 
     let message = exit.signed_root();

eth2/state_processing/src/per_block_processing/verify_proposer_slashing.rs

@@ -7,7 +7,7 @@ use types::*;
 ///
 /// Returns `Ok(())` if the `ProposerSlashing` is valid, otherwise indicates the reason for invalidity.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 pub fn verify_proposer_slashing(
     proposer_slashing: &ProposerSlashing,
     state: &BeaconState,
@@ -21,34 +21,28 @@ pub fn verify_proposer_slashing(
         })?;
 
     verify!(
-        proposer_slashing.proposal_1.slot == proposer_slashing.proposal_2.slot,
+        proposer_slashing.header_1.slot == proposer_slashing.header_2.slot,
         Invalid::ProposalSlotMismatch(
-            proposer_slashing.proposal_1.slot,
+            proposer_slashing.header_1.slot,
-            proposer_slashing.proposal_2.slot
+            proposer_slashing.header_2.slot
         )
     );
 
     verify!(
-        proposer_slashing.proposal_1.shard == proposer_slashing.proposal_2.shard,
+        proposer_slashing.header_1 != proposer_slashing.header_2,
-        Invalid::ProposalShardMismatch(
+        Invalid::ProposalsIdentical
-            proposer_slashing.proposal_1.shard,
-            proposer_slashing.proposal_2.shard
-        )
-    );
-
-    verify!(
-        proposer_slashing.proposal_1.block_root != proposer_slashing.proposal_2.block_root,
-        Invalid::ProposalBlockRootMismatch(
-            proposer_slashing.proposal_1.block_root,
-            proposer_slashing.proposal_2.block_root
-        )
     );
 
     verify!(!proposer.slashed, Invalid::ProposerAlreadySlashed);
 
     verify!(
-        verify_proposal_signature(
+        proposer.withdrawable_epoch > state.slot.epoch(spec.slots_per_epoch),
-            &proposer_slashing.proposal_1,
+        Invalid::ProposerAlreadyWithdrawn(proposer_slashing.proposer_index)
+    );
+
+    verify!(
+        verify_header_signature(
+            &proposer_slashing.header_1,
             &proposer.pubkey,
             &state.fork,
             spec
@@ -56,8 +50,8 @@ pub fn verify_proposer_slashing(
         Invalid::BadProposal1Signature
     );
     verify!(
-        verify_proposal_signature(
+        verify_header_signature(
-            &proposer_slashing.proposal_2,
+            &proposer_slashing.header_2,
             &proposer.pubkey,
             &state.fork,
             spec
@@ -71,17 +65,19 @@ pub fn verify_proposer_slashing(
 /// Verifies the signature of a proposal.
 ///
 /// Returns `true` if the signature is valid.
-fn verify_proposal_signature(
+///
-    proposal: &Proposal,
+/// Spec v0.5.0
+fn verify_header_signature(
+    header: &BeaconBlockHeader,
     pubkey: &PublicKey,
     fork: &Fork,
     spec: &ChainSpec,
 ) -> bool {
-    let message = proposal.signed_root();
+    let message = header.signed_root();
     let domain = spec.get_domain(
-        proposal.slot.epoch(spec.slots_per_epoch),
+        header.slot.epoch(spec.slots_per_epoch),
-        Domain::Proposal,
+        Domain::BeaconBlock,
         fork,
     );
-    proposal.signature.verify(&message[..], domain, pubkey)
+    header.signature.verify(&message[..], domain, pubkey)
 }

eth2/state_processing/src/per_block_processing/verify_slashable_attestation.rs

@@ -1,8 +1,8 @@
 use super::errors::{
     SlashableAttestationInvalid as Invalid, SlashableAttestationValidationError as Error,
 };
+use crate::common::verify_bitfield_length;
 use ssz::TreeHash;
-use types::beacon_state::helpers::verify_bitfield_length;
 use types::*;
 
 /// Indicates if a `SlashableAttestation` is valid to be included in a block in the current epoch of the given
@@ -10,7 +10,7 @@ use types::*;
 ///
 /// Returns `Ok(())` if the `SlashableAttestation` is valid, otherwise indicates the reason for invalidity.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 pub fn verify_slashable_attestation(
     state: &BeaconState,
     slashable_attestation: &SlashableAttestation,

eth2/state_processing/src/per_block_processing/verify_transfer.rs

@@ -10,16 +10,16 @@ use types::*;
 ///
 /// Note: this function is incomplete.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 pub fn verify_transfer(
     state: &BeaconState,
     transfer: &Transfer,
     spec: &ChainSpec,
 ) -> Result<(), Error> {
-    let from_balance = *state
+    let sender_balance = *state
         .validator_balances
-        .get(transfer.from as usize)
+        .get(transfer.sender as usize)
-        .ok_or_else(|| Error::Invalid(Invalid::FromValidatorUnknown(transfer.from)))?;
+        .ok_or_else(|| Error::Invalid(Invalid::FromValidatorUnknown(transfer.sender)))?;
 
     let total_amount = transfer
         .amount
@@ -27,19 +27,22 @@ pub fn verify_transfer(
         .ok_or_else(|| Error::Invalid(Invalid::FeeOverflow(transfer.amount, transfer.fee)))?;
 
     verify!(
-        from_balance >= transfer.amount,
+        sender_balance >= transfer.amount,
-        Invalid::FromBalanceInsufficient(transfer.amount, from_balance)
+        Invalid::FromBalanceInsufficient(transfer.amount, sender_balance)
     );
 
     verify!(
-        from_balance >= transfer.fee,
+        sender_balance >= transfer.fee,
-        Invalid::FromBalanceInsufficient(transfer.fee, from_balance)
+        Invalid::FromBalanceInsufficient(transfer.fee, sender_balance)
     );
 
     verify!(
-        (from_balance == total_amount)
+        (sender_balance == total_amount)
-            || (from_balance >= (total_amount + spec.min_deposit_amount)),
+            || (sender_balance >= (total_amount + spec.min_deposit_amount)),
-        Invalid::InvalidResultingFromBalance(from_balance - total_amount, spec.min_deposit_amount)
+        Invalid::InvalidResultingFromBalance(
+            sender_balance - total_amount,
+            spec.min_deposit_amount
+        )
     );
 
     verify!(
@@ -47,25 +50,25 @@ pub fn verify_transfer(
         Invalid::StateSlotMismatch(state.slot, transfer.slot)
     );
 
-    let from_validator = state
+    let sender_validator = state
         .validator_registry
-        .get(transfer.from as usize)
+        .get(transfer.sender as usize)
-        .ok_or_else(|| Error::Invalid(Invalid::FromValidatorUnknown(transfer.from)))?;
+        .ok_or_else(|| Error::Invalid(Invalid::FromValidatorUnknown(transfer.sender)))?;
     let epoch = state.slot.epoch(spec.slots_per_epoch);
 
     verify!(
-        from_validator.is_withdrawable_at(epoch)
+        sender_validator.is_withdrawable_at(epoch)
-            || from_validator.activation_epoch == spec.far_future_epoch,
+            || sender_validator.activation_epoch == spec.far_future_epoch,
-        Invalid::FromValidatorIneligableForTransfer(transfer.from)
+        Invalid::FromValidatorIneligableForTransfer(transfer.sender)
     );
 
     let transfer_withdrawal_credentials = Hash256::from_slice(
         &get_withdrawal_credentials(&transfer.pubkey, spec.bls_withdrawal_prefix_byte)[..],
     );
     verify!(
-        from_validator.withdrawal_credentials == transfer_withdrawal_credentials,
+        sender_validator.withdrawal_credentials == transfer_withdrawal_credentials,
         Invalid::WithdrawalCredentialsMismatch(
-            from_validator.withdrawal_credentials,
+            sender_validator.withdrawal_credentials,
             transfer_withdrawal_credentials
         )
     );
@@ -91,22 +94,23 @@ pub fn verify_transfer(
 ///
 /// Does not check that the transfer is valid, however checks for overflow in all actions.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 pub fn execute_transfer(
     state: &mut BeaconState,
     transfer: &Transfer,
     spec: &ChainSpec,
 ) -> Result<(), Error> {
-    let from_balance = *state
+    let sender_balance = *state
         .validator_balances
-        .get(transfer.from as usize)
+        .get(transfer.sender as usize)
-        .ok_or_else(|| Error::Invalid(Invalid::FromValidatorUnknown(transfer.from)))?;
+        .ok_or_else(|| Error::Invalid(Invalid::FromValidatorUnknown(transfer.sender)))?;
-    let to_balance = *state
+    let recipient_balance = *state
         .validator_balances
-        .get(transfer.to as usize)
+        .get(transfer.recipient as usize)
-        .ok_or_else(|| Error::Invalid(Invalid::ToValidatorUnknown(transfer.to)))?;
+        .ok_or_else(|| Error::Invalid(Invalid::ToValidatorUnknown(transfer.recipient)))?;
 
-    let proposer_index = state.get_beacon_proposer_index(state.slot, spec)?;
+    let proposer_index =
+        state.get_beacon_proposer_index(state.slot, RelativeEpoch::Current, spec)?;
     let proposer_balance = state.validator_balances[proposer_index];
 
     let total_amount = transfer
@@ -114,14 +118,22 @@ pub fn execute_transfer(
         .checked_add(transfer.fee)
         .ok_or_else(|| Error::Invalid(Invalid::FeeOverflow(transfer.amount, transfer.fee)))?;
 
-    state.validator_balances[transfer.from as usize] =
+    state.validator_balances[transfer.sender as usize] =
-        from_balance.checked_sub(total_amount).ok_or_else(|| {
+        sender_balance.checked_sub(total_amount).ok_or_else(|| {
-            Error::Invalid(Invalid::FromBalanceInsufficient(total_amount, from_balance))
+            Error::Invalid(Invalid::FromBalanceInsufficient(
+                total_amount,
+                sender_balance,
+            ))
         })?;
 
-    state.validator_balances[transfer.to as usize] = to_balance
+    state.validator_balances[transfer.recipient as usize] = recipient_balance
         .checked_add(transfer.amount)
-        .ok_or_else(|| Error::Invalid(Invalid::ToBalanceOverflow(to_balance, transfer.amount)))?;
+        .ok_or_else(|| {
+            Error::Invalid(Invalid::ToBalanceOverflow(
+                recipient_balance,
+                transfer.amount,
+            ))
+        })?;
 
     state.validator_balances[proposer_index] =
         proposer_balance.checked_add(transfer.fee).ok_or_else(|| {

eth2/state_processing/src/per_epoch_processing.rs

@@ -1,15 +1,24 @@
+use apply_rewards::apply_rewards;
 use errors::EpochProcessingError as Error;
-use integer_sqrt::IntegerSquareRoot;
+use process_ejections::process_ejections;
-use rayon::prelude::*;
+use process_exit_queue::process_exit_queue;
+use process_slashings::process_slashings;
 use ssz::TreeHash;
 use std::collections::HashMap;
-use types::{validator_registry::get_active_validator_indices, *};
+use types::*;
+use update_registry_and_shuffling_data::update_registry_and_shuffling_data;
 use validator_statuses::{TotalBalances, ValidatorStatuses};
 use winning_root::{winning_root, WinningRoot};
 
+pub mod apply_rewards;
 pub mod errors;
+pub mod get_attestation_participants;
 pub mod inclusion_distance;
+pub mod process_ejections;
+pub mod process_exit_queue;
+pub mod process_slashings;
 pub mod tests;
+pub mod update_registry_and_shuffling_data;
 pub mod validator_statuses;
 pub mod winning_root;
 
@@ -23,35 +32,51 @@ pub type WinningRootHashSet = HashMap<u64, WinningRoot>;
 /// Mutates the given `BeaconState`, returning early if an error is encountered. If an error is
 /// returned, a state might be "half-processed" and therefore in an invalid state.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 pub fn per_epoch_processing(state: &mut BeaconState, spec: &ChainSpec) -> Result<(), Error> {
-    // Ensure all of the caches are built.
+    // Ensure the previous and next epoch caches are built.
     state.build_epoch_cache(RelativeEpoch::Previous, spec)?;
     state.build_epoch_cache(RelativeEpoch::Current, spec)?;
-    state.build_epoch_cache(RelativeEpoch::Next, spec)?;
 
-    let mut statuses = initialize_validator_statuses(&state, spec)?;
+    // Load the struct we use to assign validators into sets based on their participation.
+    //
+    // E.g., attestation in the previous epoch, attested to the head, etc.
+    let mut validator_statuses = ValidatorStatuses::new(state, spec)?;
+    validator_statuses.process_attestations(&state, spec)?;
 
-    process_eth1_data(state, spec);
+    // Justification.
+    update_justification_and_finalization(state, &validator_statuses.total_balances, spec)?;
 
-    process_justification(state, &statuses.total_balances, spec);
+    // Crosslinks.
-
-    // Crosslinks
     let winning_root_for_shards = process_crosslinks(state, spec)?;
 
-    // Rewards and Penalities
+    // Eth1 data.
-    process_rewards_and_penalities(state, &mut statuses, &winning_root_for_shards, spec)?;
+    maybe_reset_eth1_period(state, spec);
 
-    // Ejections
+    // Rewards and Penalities.
-    state.process_ejections(spec);
+    apply_rewards(
+        state,
+        &mut validator_statuses,
+        &winning_root_for_shards,
+        spec,
+    )?;
 
-    // Validator Registry
+    // Ejections.
-    process_validator_registry(state, spec)?;
+    process_ejections(state, spec)?;
 
-    // Final updates
+    // Validator Registry.
-    update_active_tree_index_roots(state, spec)?;
+    update_registry_and_shuffling_data(
-    update_latest_slashed_balances(state, spec);
+        state,
-    clean_attestations(state, spec);
+        validator_statuses.total_balances.current_epoch,
+        spec,
+    )?;
+
+    // Slashings and exit queue.
+    process_slashings(state, validator_statuses.total_balances.current_epoch, spec)?;
+    process_exit_queue(state, spec);
+
+    // Final updates.
+    finish_epoch_update(state, spec)?;
 
     // Rotate the epoch caches to suit the epoch transition.
     state.advance_caches();
@@ -59,43 +84,16 @@ pub fn per_epoch_processing(state: &mut BeaconState, spec: &ChainSpec) -> Result
     Ok(())
 }
 
-/// Returns a list of active validator indices for the state's current epoch.
+/// Maybe resets the eth1 period.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
-pub fn calculate_active_validator_indices(state: &BeaconState, spec: &ChainSpec) -> Vec<usize> {
+pub fn maybe_reset_eth1_period(state: &mut BeaconState, spec: &ChainSpec) {
-    get_active_validator_indices(
-        &state.validator_registry,
-        state.slot.epoch(spec.slots_per_epoch),
-    )
-}
-
-/// Calculates various sets of attesters, including:
-///
-/// - current epoch attesters
-/// - current epoch boundary attesters
-/// - previous epoch attesters
-/// - etc.
-///
-/// Spec v0.4.0
-pub fn initialize_validator_statuses(
-    state: &BeaconState,
-    spec: &ChainSpec,
-) -> Result<ValidatorStatuses, BeaconStateError> {
-    let mut statuses = ValidatorStatuses::new(state, spec);
-
-    statuses.process_attestations(&state, &state.latest_attestations, spec)?;
-
-    Ok(statuses)
-}
-
-/// Spec v0.4.0
-pub fn process_eth1_data(state: &mut BeaconState, spec: &ChainSpec) {
     let next_epoch = state.next_epoch(spec);
     let voting_period = spec.epochs_per_eth1_voting_period;
 
     if next_epoch % voting_period == 0 {
         for eth1_data_vote in &state.eth1_data_votes {
-            if eth1_data_vote.vote_count * 2 > voting_period {
+            if eth1_data_vote.vote_count * 2 > voting_period * spec.slots_per_epoch {
                 state.latest_eth1_data = eth1_data_vote.eth1_data.clone();
             }
         }
@@ -110,79 +108,68 @@ pub fn process_eth1_data(state: &mut BeaconState, spec: &ChainSpec) {
 /// - `justified_epoch`
 /// - `previous_justified_epoch`
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
-pub fn process_justification(
+pub fn update_justification_and_finalization(
     state: &mut BeaconState,
     total_balances: &TotalBalances,
     spec: &ChainSpec,
-) {
+) -> Result<(), Error> {
     let previous_epoch = state.previous_epoch(spec);
     let current_epoch = state.current_epoch(spec);
 
-    let mut new_justified_epoch = state.justified_epoch;
+    let mut new_justified_epoch = state.current_justified_epoch;
+    let mut new_finalized_epoch = state.finalized_epoch;
+
+    // Rotate the justification bitfield up one epoch to make room for the current epoch.
     state.justification_bitfield <<= 1;
 
-    // If > 2/3 of the total balance attested to the previous epoch boundary
+    // If the previous epoch gets justified, full the second last bit.
-    //
+    if (total_balances.previous_epoch_boundary_attesters * 3) >= (total_balances.previous_epoch * 2)
-    // - Set the 2nd bit of the bitfield.
-    // - Set the previous epoch to be justified.
-    if (3 * total_balances.previous_epoch_boundary_attesters) >= (2 * total_balances.previous_epoch)
     {
-        state.justification_bitfield |= 2;
         new_justified_epoch = previous_epoch;
+        state.justification_bitfield |= 2;
     }
-    // If > 2/3 of the total balance attested to the previous epoch boundary
+    // If the current epoch gets justified, fill the last bit.
-    //
+    if (total_balances.current_epoch_boundary_attesters * 3) >= (total_balances.current_epoch * 2) {
-    // - Set the 1st bit of the bitfield.
-    // - Set the current epoch to be justified.
-    if (3 * total_balances.current_epoch_boundary_attesters) >= (2 * total_balances.current_epoch) {
-        state.justification_bitfield |= 1;
         new_justified_epoch = current_epoch;
+        state.justification_bitfield |= 1;
     }
 
-    // If:
+    let bitfield = state.justification_bitfield;
-    //
+
-    // - All three epochs prior to this epoch have been justified.
+    // The 2nd/3rd/4th most recent epochs are all justified, the 2nd using the 4th as source.
-    // - The previous justified justified epoch was three epochs ago.
+    if ((bitfield >> 1) % 8 == 0b111) & (state.previous_justified_epoch == current_epoch - 3) {
-    //
+        new_finalized_epoch = state.previous_justified_epoch;
-    // Then, set the finalized epoch to be three epochs ago.
-    if ((state.justification_bitfield >> 1) % 8 == 0b111)
-        & (state.previous_justified_epoch == previous_epoch - 2)
-    {
-        state.finalized_epoch = state.previous_justified_epoch;
     }
-    // If:
+    // The 2nd/3rd most recent epochs are both justified, the 2nd using the 3rd as source.
-    //
+    if ((bitfield >> 1) % 4 == 0b11) & (state.previous_justified_epoch == current_epoch - 2) {
-    // - Both two epochs prior to this epoch have been justified.
+        new_finalized_epoch = state.previous_justified_epoch;
-    // - The previous justified epoch was two epochs ago.
-    //
-    // Then, set the finalized epoch to two epochs ago.
-    if ((state.justification_bitfield >> 1) % 4 == 0b11)
-        & (state.previous_justified_epoch == previous_epoch - 1)
-    {
-        state.finalized_epoch = state.previous_justified_epoch;
     }
-    // If:
+    // The 1st/2nd/3rd most recent epochs are all justified, the 1st using the 2nd as source.
-    //
+    if (bitfield % 8 == 0b111) & (state.current_justified_epoch == current_epoch - 2) {
-    // - This epoch and the two prior have been justified.
+        new_finalized_epoch = state.current_justified_epoch;
-    // - The presently justified epoch was two epochs ago.
-    //
-    // Then, set the finalized epoch to two epochs ago.
-    if (state.justification_bitfield % 8 == 0b111) & (state.justified_epoch == previous_epoch - 1) {
-        state.finalized_epoch = state.justified_epoch;
     }
-    // If:
+    // The 1st/2nd most recent epochs are both justified, the 1st using the 2nd as source.
-    //
+    if (bitfield % 4 == 0b11) & (state.current_justified_epoch == current_epoch - 1) {
-    // - This epoch and the epoch prior to it have been justified.
+        new_finalized_epoch = state.current_justified_epoch;
-    // - Set the previous epoch to be justified.
-    //
-    // Then, set the finalized epoch to be the previous epoch.
-    if (state.justification_bitfield % 4 == 0b11) & (state.justified_epoch == previous_epoch) {
-        state.finalized_epoch = state.justified_epoch;
     }
 
-    state.previous_justified_epoch = state.justified_epoch;
+    state.previous_justified_epoch = state.current_justified_epoch;
-    state.justified_epoch = new_justified_epoch;
+    state.previous_justified_root = state.current_justified_root;
+
+    if new_justified_epoch != state.current_justified_epoch {
+        state.current_justified_epoch = new_justified_epoch;
+        state.current_justified_root =
+            *state.get_block_root(new_justified_epoch.start_slot(spec.slots_per_epoch), spec)?;
+    }
+
+    if new_finalized_epoch != state.finalized_epoch {
+        state.finalized_epoch = new_finalized_epoch;
+        state.finalized_root =
+            *state.get_block_root(new_finalized_epoch.start_slot(spec.slots_per_epoch), spec)?;
+    }
+
+    Ok(())
 }
 
 /// Updates the following fields on the `BeaconState`:
@@ -191,23 +178,11 @@ pub fn process_justification(
 ///
 /// Also returns a `WinningRootHashSet` for later use during epoch processing.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 pub fn process_crosslinks(
     state: &mut BeaconState,
     spec: &ChainSpec,
 ) -> Result<WinningRootHashSet, Error> {
-    let current_epoch_attestations: Vec<&PendingAttestation> = state
-        .latest_attestations
-        .par_iter()
-        .filter(|a| a.data.slot.epoch(spec.slots_per_epoch) == state.current_epoch(spec))
-        .collect();
-
-    let previous_epoch_attestations: Vec<&PendingAttestation> = state
-        .latest_attestations
-        .par_iter()
-        .filter(|a| a.data.slot.epoch(spec.slots_per_epoch) == state.previous_epoch(spec))
-        .collect();
-
     let mut winning_root_for_shards: WinningRootHashSet = HashMap::new();
 
     let previous_and_current_epoch_slots: Vec<Slot> = state
@@ -221,24 +196,18 @@ pub fn process_crosslinks(
         let crosslink_committees_at_slot =
             state.get_crosslink_committees_at_slot(slot, spec)?.clone();
 
-        for (crosslink_committee, shard) in crosslink_committees_at_slot {
+        for c in crosslink_committees_at_slot {
-            let shard = shard as u64;
+            let shard = c.shard as u64;
 
-            let winning_root = winning_root(
+            let winning_root = winning_root(state, shard, spec)?;
-                state,
-                shard,
-                &current_epoch_attestations[..],
-                &previous_epoch_attestations[..],
-                spec,
-            )?;
 
             if let Some(winning_root) = winning_root {
-                let total_committee_balance = state.get_total_balance(&crosslink_committee, spec);
+                let total_committee_balance = state.get_total_balance(&c.committee, spec)?;
 
                 // TODO: I think this has a bug.
                 if (3 * winning_root.total_attesting_balance) >= (2 * total_committee_balance) {
                     state.latest_crosslinks[shard as usize] = Crosslink {
-                        epoch: state.current_epoch(spec),
+                        epoch: slot.epoch(spec.slots_per_epoch),
                         crosslink_data_root: winning_root.crosslink_data_root,
                     }
                 }
@@ -250,248 +219,53 @@ pub fn process_crosslinks(
     Ok(winning_root_for_shards)
 }
 
-/// Updates the following fields on the BeaconState:
+/// Finish up an epoch update.
 ///
-/// - `validator_balances`
+/// Spec v0.5.0
-///
+pub fn finish_epoch_update(state: &mut BeaconState, spec: &ChainSpec) -> Result<(), Error> {
-/// Spec v0.4.0
+    let current_epoch = state.current_epoch(spec);
-pub fn process_rewards_and_penalities(
-    state: &mut BeaconState,
-    statuses: &mut ValidatorStatuses,
-    winning_root_for_shards: &WinningRootHashSet,
-    spec: &ChainSpec,
-) -> Result<(), Error> {
     let next_epoch = state.next_epoch(spec);
 
-    statuses.process_winning_roots(state, winning_root_for_shards, spec)?;
+    // This is a hack to allow us to update index roots and slashed balances for the next epoch.
+    //
+    // The indentation here is to make it obvious where the weird stuff happens.
+    {
+        state.slot += 1;
 
-    let total_balances = &statuses.total_balances;
+        // Set active index root
-
+        let active_index_root = Hash256::from_slice(
-    let base_reward_quotient =
+            &state
-        total_balances.previous_epoch.integer_sqrt() / spec.base_reward_quotient;
+                .get_active_validator_indices(next_epoch + spec.activation_exit_delay)
-
+                .hash_tree_root()[..],
-    // Guard against a divide-by-zero during the validator balance update.
-    if base_reward_quotient == 0 {
-        return Err(Error::BaseRewardQuotientIsZero);
-    }
-    // Guard against a divide-by-zero during the validator balance update.
-    if total_balances.previous_epoch == 0 {
-        return Err(Error::PreviousTotalBalanceIsZero);
-    }
-    // Guard against an out-of-bounds during the validator balance update.
-    if statuses.statuses.len() != state.validator_balances.len() {
-        return Err(Error::ValidatorStatusesInconsistent);
-    }
-
-    // Justification and finalization
-
-    let epochs_since_finality = next_epoch - state.finalized_epoch;
-
-    state.validator_balances = state
-        .validator_balances
-        .par_iter()
-        .enumerate()
-        .map(|(index, &balance)| {
-            let mut balance = balance;
-            let status = &statuses.statuses[index];
-            let base_reward = state.base_reward(index, base_reward_quotient, spec);
-
-            if epochs_since_finality <= 4 {
-                // Expected FFG source
-                if status.is_previous_epoch_attester {
-                    safe_add_assign!(
-                        balance,
-                        base_reward * total_balances.previous_epoch_attesters
-                            / total_balances.previous_epoch
         );
-                } else if status.is_active_in_previous_epoch {
+        state.set_active_index_root(next_epoch, active_index_root, spec)?;
-                    safe_sub_assign!(balance, base_reward);
-                }
 
-                // Expected FFG target
+        // Set total slashed balances
-                if status.is_previous_epoch_boundary_attester {
+        state.set_slashed_balance(
-                    safe_add_assign!(
+            next_epoch,
-                        balance,
+            state.get_slashed_balance(current_epoch, spec)?,
-                        base_reward * total_balances.previous_epoch_boundary_attesters
-                            / total_balances.previous_epoch
-                    );
-                } else if status.is_active_in_previous_epoch {
-                    safe_sub_assign!(balance, base_reward);
-                }
-
-                // Expected beacon chain head
-                if status.is_previous_epoch_head_attester {
-                    safe_add_assign!(
-                        balance,
-                        base_reward * total_balances.previous_epoch_head_attesters
-                            / total_balances.previous_epoch
-                    );
-                } else if status.is_active_in_previous_epoch {
-                    safe_sub_assign!(balance, base_reward);
-                };
-            } else {
-                let inactivity_penalty = state.inactivity_penalty(
-                    index,
-                    epochs_since_finality,
-                    base_reward_quotient,
             spec,
-                );
+        )?;
 
-                if status.is_active_in_previous_epoch {
+        // Set randao mix
-                    if !status.is_previous_epoch_attester {
+        state.set_randao_mix(
-                        safe_sub_assign!(balance, inactivity_penalty);
+            next_epoch,
-                    }
+            *state.get_randao_mix(current_epoch, spec)?,
-                    if !status.is_previous_epoch_boundary_attester {
+            spec,
-                        safe_sub_assign!(balance, inactivity_penalty);
+        )?;
-                    }
+
-                    if !status.is_previous_epoch_head_attester {
+        state.slot -= 1;
-                        safe_sub_assign!(balance, inactivity_penalty);
     }
 
-                    if state.validator_registry[index].slashed {
+    if next_epoch.as_u64() % (spec.slots_per_historical_root as u64 / spec.slots_per_epoch) == 0 {
-                        let base_reward = state.base_reward(index, base_reward_quotient, spec);
+        let historical_batch: HistoricalBatch = state.historical_batch();
-                        safe_sub_assign!(balance, 2 * inactivity_penalty + base_reward);
+        state
-                    }
+            .historical_roots
-                }
+            .push(Hash256::from_slice(&historical_batch.hash_tree_root()[..]));
     }
 
-            // Crosslinks
+    state.previous_epoch_attestations = state.current_epoch_attestations.clone();
-
+    state.current_epoch_attestations = vec![];
-            if let Some(ref info) = status.winning_root_info {
-                safe_add_assign!(
-                    balance,
-                    base_reward * info.total_attesting_balance / info.total_committee_balance
-                );
-            } else {
-                safe_sub_assign!(balance, base_reward);
-            }
-
-            balance
-        })
-        .collect();
-
-    // Attestation inclusion
-
-    // Guard against an out-of-bounds during the attester inclusion balance update.
-    if statuses.statuses.len() != state.validator_registry.len() {
-        return Err(Error::ValidatorStatusesInconsistent);
-    }
-
-    for (index, _validator) in state.validator_registry.iter().enumerate() {
-        let status = &statuses.statuses[index];
-
-        if status.is_previous_epoch_attester {
-            let proposer_index = status.inclusion_info.proposer_index;
-            let inclusion_distance = status.inclusion_info.distance;
-
-            let base_reward = state.base_reward(proposer_index, base_reward_quotient, spec);
-
-            if inclusion_distance > 0 && inclusion_distance < Slot::max_value() {
-                safe_add_assign!(
-                    state.validator_balances[proposer_index],
-                    base_reward * spec.min_attestation_inclusion_delay
-                        / inclusion_distance.as_u64()
-                )
-            }
-        }
-    }
 
     Ok(())
 }
-
-/// Peforms a validator registry update, if required.
-///
-/// Spec v0.4.0
-pub fn process_validator_registry(state: &mut BeaconState, spec: &ChainSpec) -> Result<(), Error> {
-    let current_epoch = state.current_epoch(spec);
-    let next_epoch = state.next_epoch(spec);
-
-    state.previous_shuffling_epoch = state.current_shuffling_epoch;
-    state.previous_shuffling_start_shard = state.current_shuffling_start_shard;
-
-    state.previous_shuffling_seed = state.current_shuffling_seed;
-
-    let should_update_validator_registy = if state.finalized_epoch
-        > state.validator_registry_update_epoch
-    {
-        (0..state.get_current_epoch_committee_count(spec)).all(|i| {
-            let shard = (state.current_shuffling_start_shard + i as u64) % spec.shard_count;
-            state.latest_crosslinks[shard as usize].epoch > state.validator_registry_update_epoch
-        })
-    } else {
-        false
-    };
-
-    if should_update_validator_registy {
-        state.update_validator_registry(spec);
-
-        state.current_shuffling_epoch = next_epoch;
-        state.current_shuffling_start_shard = (state.current_shuffling_start_shard
-            + state.get_current_epoch_committee_count(spec) as u64)
-            % spec.shard_count;
-        state.current_shuffling_seed = state.generate_seed(state.current_shuffling_epoch, spec)?
-    } else {
-        let epochs_since_last_registry_update =
-            current_epoch - state.validator_registry_update_epoch;
-        if (epochs_since_last_registry_update > 1)
-            & epochs_since_last_registry_update.is_power_of_two()
-        {
-            state.current_shuffling_epoch = next_epoch;
-            state.current_shuffling_seed =
-                state.generate_seed(state.current_shuffling_epoch, spec)?
-        }
-    }
-
-    state.process_slashings(spec);
-    state.process_exit_queue(spec);
-
-    Ok(())
-}
-
-/// Updates the state's `latest_active_index_roots` field with a tree hash the active validator
-/// indices for the next epoch.
-///
-/// Spec v0.4.0
-pub fn update_active_tree_index_roots(
-    state: &mut BeaconState,
-    spec: &ChainSpec,
-) -> Result<(), Error> {
-    let next_epoch = state.next_epoch(spec);
-
-    let active_tree_root = get_active_validator_indices(
-        &state.validator_registry,
-        next_epoch + Epoch::from(spec.activation_exit_delay),
-    )
-    .hash_tree_root();
-
-    state.latest_active_index_roots[(next_epoch.as_usize()
-        + spec.activation_exit_delay as usize)
-        % spec.latest_active_index_roots_length] = Hash256::from_slice(&active_tree_root[..]);
-
-    Ok(())
-}
-
-/// Advances the state's `latest_slashed_balances` field.
-///
-/// Spec v0.4.0
-pub fn update_latest_slashed_balances(state: &mut BeaconState, spec: &ChainSpec) {
-    let current_epoch = state.current_epoch(spec);
-    let next_epoch = state.next_epoch(spec);
-
-    state.latest_slashed_balances[next_epoch.as_usize() % spec.latest_slashed_exit_length] =
-        state.latest_slashed_balances[current_epoch.as_usize() % spec.latest_slashed_exit_length];
-}
-
-/// Removes all pending attestations from the previous epoch.
-///
-/// Spec v0.4.0
-pub fn clean_attestations(state: &mut BeaconState, spec: &ChainSpec) {
-    let current_epoch = state.current_epoch(spec);
-
-    state.latest_attestations = state
-        .latest_attestations
-        .iter()
-        .filter(|a| a.data.slot.epoch(spec.slots_per_epoch) >= current_epoch)
-        .cloned()
-        .collect();
-}

eth2/state_processing/src/per_epoch_processing/apply_rewards.rs

@@ -0,0 +1,334 @@
+use super::validator_statuses::{TotalBalances, ValidatorStatus, ValidatorStatuses};
+use super::{Error, WinningRootHashSet};
+use integer_sqrt::IntegerSquareRoot;
+use types::*;
+
+/// Use to track the changes to a validators balance.
+#[derive(Default, Clone)]
+pub struct Delta {
+    rewards: u64,
+    penalties: u64,
+}
+
+impl Delta {
+    /// Reward the validator with the `reward`.
+    pub fn reward(&mut self, reward: u64) {
+        self.rewards += reward;
+    }
+
+    /// Penalize the validator with the `penalty`.
+    pub fn penalize(&mut self, penalty: u64) {
+        self.penalties += penalty;
+    }
+}
+
+impl std::ops::AddAssign for Delta {
+    /// Use wrapping addition as that is how it's defined in the spec.
+    fn add_assign(&mut self, other: Delta) {
+        self.rewards += other.rewards;
+        self.penalties += other.penalties;
+    }
+}
+
+/// Apply attester and proposer rewards.
+///
+/// Spec v0.5.0
+pub fn apply_rewards(
+    state: &mut BeaconState,
+    validator_statuses: &mut ValidatorStatuses,
+    winning_root_for_shards: &WinningRootHashSet,
+    spec: &ChainSpec,
+) -> Result<(), Error> {
+    // Guard against an out-of-bounds during the validator balance update.
+    if validator_statuses.statuses.len() != state.validator_balances.len() {
+        return Err(Error::ValidatorStatusesInconsistent);
+    }
+    // Guard against an out-of-bounds during the attester inclusion balance update.
+    if validator_statuses.statuses.len() != state.validator_registry.len() {
+        return Err(Error::ValidatorStatusesInconsistent);
+    }
+
+    let mut deltas = vec![Delta::default(); state.validator_balances.len()];
+
+    get_justification_and_finalization_deltas(&mut deltas, state, &validator_statuses, spec)?;
+    get_crosslink_deltas(&mut deltas, state, &validator_statuses, spec)?;
+
+    // Apply the proposer deltas if we are finalizing normally.
+    //
+    // This is executed slightly differently to the spec because of the way our functions are
+    // structured. It should be functionally equivalent.
+    if epochs_since_finality(state, spec) <= 4 {
+        get_proposer_deltas(
+            &mut deltas,
+            state,
+            validator_statuses,
+            winning_root_for_shards,
+            spec,
+        )?;
+    }
+
+    // Apply the deltas, over-flowing but not under-flowing (saturating at 0 instead).
+    for (i, delta) in deltas.iter().enumerate() {
+        state.validator_balances[i] += delta.rewards;
+        state.validator_balances[i] = state.validator_balances[i].saturating_sub(delta.penalties);
+    }
+
+    Ok(())
+}
+
+/// Applies the attestation inclusion reward to each proposer for every validator who included an
+/// attestation in the previous epoch.
+///
+/// Spec v0.5.0
+fn get_proposer_deltas(
+    deltas: &mut Vec<Delta>,
+    state: &mut BeaconState,
+    validator_statuses: &mut ValidatorStatuses,
+    winning_root_for_shards: &WinningRootHashSet,
+    spec: &ChainSpec,
+) -> Result<(), Error> {
+    // Update statuses with the information from winning roots.
+    validator_statuses.process_winning_roots(state, winning_root_for_shards, spec)?;
+
+    for (index, validator) in validator_statuses.statuses.iter().enumerate() {
+        let mut delta = Delta::default();
+
+        if validator.is_previous_epoch_attester {
+            let inclusion = validator
+                .inclusion_info
+                .expect("It is a logic error for an attester not to have an inclusion distance.");
+
+            let base_reward = get_base_reward(
+                state,
+                inclusion.proposer_index,
+                validator_statuses.total_balances.previous_epoch,
+                spec,
+            )?;
+
+            if inclusion.proposer_index >= deltas.len() {
+                return Err(Error::ValidatorStatusesInconsistent);
+            }
+
+            delta.reward(base_reward / spec.attestation_inclusion_reward_quotient);
+        }
+
+        deltas[index] += delta;
+    }
+
+    Ok(())
+}
+
+/// Apply rewards for participation in attestations during the previous epoch.
+///
+/// Spec v0.5.0
+fn get_justification_and_finalization_deltas(
+    deltas: &mut Vec<Delta>,
+    state: &BeaconState,
+    validator_statuses: &ValidatorStatuses,
+    spec: &ChainSpec,
+) -> Result<(), Error> {
+    let epochs_since_finality = epochs_since_finality(state, spec);
+
+    for (index, validator) in validator_statuses.statuses.iter().enumerate() {
+        let base_reward = get_base_reward(
+            state,
+            index,
+            validator_statuses.total_balances.previous_epoch,
+            spec,
+        )?;
+        let inactivity_penalty = get_inactivity_penalty(
+            state,
+            index,
+            epochs_since_finality.as_u64(),
+            validator_statuses.total_balances.previous_epoch,
+            spec,
+        )?;
+
+        let delta = if epochs_since_finality <= 4 {
+            compute_normal_justification_and_finalization_delta(
+                &validator,
+                &validator_statuses.total_balances,
+                base_reward,
+                spec,
+            )
+        } else {
+            compute_inactivity_leak_delta(&validator, base_reward, inactivity_penalty, spec)
+        };
+
+        deltas[index] += delta;
+    }
+
+    Ok(())
+}
+
+/// Determine the delta for a single validator, if the chain is finalizing normally.
+///
+/// Spec v0.5.0
+fn compute_normal_justification_and_finalization_delta(
+    validator: &ValidatorStatus,
+    total_balances: &TotalBalances,
+    base_reward: u64,
+    spec: &ChainSpec,
+) -> Delta {
+    let mut delta = Delta::default();
+
+    let boundary_attesting_balance = total_balances.previous_epoch_boundary_attesters;
+    let total_balance = total_balances.previous_epoch;
+    let total_attesting_balance = total_balances.previous_epoch_attesters;
+    let matching_head_balance = total_balances.previous_epoch_boundary_attesters;
+
+    // Expected FFG source.
+    if validator.is_previous_epoch_attester {
+        delta.reward(base_reward * total_attesting_balance / total_balance);
+        // Inclusion speed bonus
+        let inclusion = validator
+            .inclusion_info
+            .expect("It is a logic error for an attester not to have an inclusion distance.");
+        delta.reward(
+            base_reward * spec.min_attestation_inclusion_delay / inclusion.distance.as_u64(),
+        );
+    } else if validator.is_active_in_previous_epoch {
+        delta.penalize(base_reward);
+    }
+
+    // Expected FFG target.
+    if validator.is_previous_epoch_boundary_attester {
+        delta.reward(base_reward / boundary_attesting_balance / total_balance);
+    } else if validator.is_active_in_previous_epoch {
+        delta.penalize(base_reward);
+    }
+
+    // Expected head.
+    if validator.is_previous_epoch_head_attester {
+        delta.reward(base_reward * matching_head_balance / total_balance);
+    } else if validator.is_active_in_previous_epoch {
+        delta.penalize(base_reward);
+    };
+
+    // Proposer bonus is handled in `apply_proposer_deltas`.
+    //
+    // This function only computes the delta for a single validator, so it cannot also return a
+    // delta for a validator.
+
+    delta
+}
+
+/// Determine the delta for a single delta, assuming the chain is _not_ finalizing normally.
+///
+/// Spec v0.5.0
+fn compute_inactivity_leak_delta(
+    validator: &ValidatorStatus,
+    base_reward: u64,
+    inactivity_penalty: u64,
+    spec: &ChainSpec,
+) -> Delta {
+    let mut delta = Delta::default();
+
+    if validator.is_active_in_previous_epoch {
+        if !validator.is_previous_epoch_attester {
+            delta.penalize(inactivity_penalty);
+        } else {
+            // If a validator did attest, apply a small penalty for getting attestations included
+            // late.
+            let inclusion = validator
+                .inclusion_info
+                .expect("It is a logic error for an attester not to have an inclusion distance.");
+            delta.reward(
+                base_reward * spec.min_attestation_inclusion_delay / inclusion.distance.as_u64(),
+            );
+            delta.penalize(base_reward);
+        }
+
+        if !validator.is_previous_epoch_boundary_attester {
+            delta.reward(inactivity_penalty);
+        }
+
+        if !validator.is_previous_epoch_head_attester {
+            delta.penalize(inactivity_penalty);
+        }
+    }
+
+    // Penalize slashed-but-inactive validators as though they were active but offline.
+    if !validator.is_active_in_previous_epoch
+        & validator.is_slashed
+        & !validator.is_withdrawable_in_current_epoch
+    {
+        delta.penalize(2 * inactivity_penalty + base_reward);
+    }
+
+    delta
+}
+
+/// Calculate the deltas based upon the winning roots for attestations during the previous epoch.
+///
+/// Spec v0.5.0
+fn get_crosslink_deltas(
+    deltas: &mut Vec<Delta>,
+    state: &BeaconState,
+    validator_statuses: &ValidatorStatuses,
+    spec: &ChainSpec,
+) -> Result<(), Error> {
+    for (index, validator) in validator_statuses.statuses.iter().enumerate() {
+        let mut delta = Delta::default();
+
+        let base_reward = get_base_reward(
+            state,
+            index,
+            validator_statuses.total_balances.previous_epoch,
+            spec,
+        )?;
+
+        if let Some(ref winning_root) = validator.winning_root_info {
+            delta.reward(
+                base_reward * winning_root.total_attesting_balance
+                    / winning_root.total_committee_balance,
+            );
+        } else {
+            delta.penalize(base_reward);
+        }
+
+        deltas[index] += delta;
+    }
+
+    Ok(())
+}
+
+/// Returns the base reward for some validator.
+///
+/// Spec v0.5.0
+fn get_base_reward(
+    state: &BeaconState,
+    index: usize,
+    previous_total_balance: u64,
+    spec: &ChainSpec,
+) -> Result<u64, BeaconStateError> {
+    if previous_total_balance == 0 {
+        Ok(0)
+    } else {
+        let adjusted_quotient = previous_total_balance.integer_sqrt() / spec.base_reward_quotient;
+        Ok(state.get_effective_balance(index, spec)? / adjusted_quotient / 5)
+    }
+}
+
+/// Returns the inactivity penalty for some validator.
+///
+/// Spec v0.5.0
+fn get_inactivity_penalty(
+    state: &BeaconState,
+    index: usize,
+    epochs_since_finality: u64,
+    previous_total_balance: u64,
+    spec: &ChainSpec,
+) -> Result<u64, BeaconStateError> {
+    Ok(get_base_reward(state, index, previous_total_balance, spec)?
+        + state.get_effective_balance(index, spec)? * epochs_since_finality
+            / spec.inactivity_penalty_quotient
+            / 2)
+}
+
+/// Returns the epochs since the last finalized epoch.
+///
+/// Spec v0.5.0
+fn epochs_since_finality(state: &BeaconState, spec: &ChainSpec) -> Epoch {
+    state.current_epoch(spec) + 1 - state.finalized_epoch
+}

eth2/state_processing/src/per_epoch_processing/errors.rs

@@ -9,6 +9,7 @@ pub enum EpochProcessingError {
     PreviousTotalBalanceIsZero,
     InclusionDistanceZero,
     ValidatorStatusesInconsistent,
+    DeltasInconsistent,
     /// Unable to get the inclusion distance for a validator that should have an inclusion
     /// distance. This indicates an internal inconsistency.
     ///

eth2/state_processing/src/per_epoch_processing/get_attestation_participants.rs

@@ -0,0 +1,38 @@
+use crate::common::verify_bitfield_length;
+use types::*;
+
+/// Returns validator indices which participated in the attestation.
+///
+/// Spec v0.5.0
+pub fn get_attestation_participants(
+    state: &BeaconState,
+    attestation_data: &AttestationData,
+    bitfield: &Bitfield,
+    spec: &ChainSpec,
+) -> Result<Vec<usize>, BeaconStateError> {
+    let epoch = attestation_data.slot.epoch(spec.slots_per_epoch);
+
+    let crosslink_committee =
+        state.get_crosslink_committee_for_shard(epoch, attestation_data.shard, spec)?;
+
+    if crosslink_committee.slot != attestation_data.slot {
+        return Err(BeaconStateError::NoCommitteeForShard);
+    }
+
+    let committee = &crosslink_committee.committee;
+
+    if !verify_bitfield_length(&bitfield, committee.len()) {
+        return Err(BeaconStateError::InvalidBitfield);
+    }
+
+    let mut participants = Vec::with_capacity(committee.len());
+    for (i, validator_index) in committee.iter().enumerate() {
+        match bitfield.get(i) {
+            Ok(bit) if bit => participants.push(*validator_index),
+            _ => {}
+        }
+    }
+    participants.shrink_to_fit();
+
+    Ok(participants)
+}

eth2/state_processing/src/per_epoch_processing/inclusion_distance.rs

@@ -1,12 +1,11 @@
 use super::errors::InclusionError;
+use super::get_attestation_participants::get_attestation_participants;
 use types::*;
 
 /// Returns the distance between the first included attestation for some validator and this
 /// slot.
 ///
-/// Note: In the spec this is defined "inline", not as a helper function.
+/// Spec v0.5.0
-///
-/// Spec v0.4.0
 pub fn inclusion_distance(
     state: &BeaconState,
     attestations: &[&PendingAttestation],
@@ -19,9 +18,7 @@ pub fn inclusion_distance(
 
 /// Returns the slot of the earliest included attestation for some validator.
 ///
-/// Note: In the spec this is defined "inline", not as a helper function.
+/// Spec v0.5.0
-///
-/// Spec v0.4.0
 pub fn inclusion_slot(
     state: &BeaconState,
     attestations: &[&PendingAttestation],
@@ -34,9 +31,7 @@ pub fn inclusion_slot(
 
 /// Finds the earliest included attestation for some validator.
 ///
-/// Note: In the spec this is defined "inline", not as a helper function.
+/// Spec v0.5.0
-///
-/// Spec v0.4.0
 fn earliest_included_attestation(
     state: &BeaconState,
     attestations: &[&PendingAttestation],
@@ -47,7 +42,7 @@ fn earliest_included_attestation(
 
     for (i, a) in attestations.iter().enumerate() {
         let participants =
-            state.get_attestation_participants(&a.data, &a.aggregation_bitfield, spec)?;
+            get_attestation_participants(state, &a.data, &a.aggregation_bitfield, spec)?;
         if participants.iter().any(|i| *i == validator_index) {
             included_attestations.push(i);
         }

eth2/state_processing/src/per_epoch_processing/process_ejections.rs

@@ -0,0 +1,28 @@
+use crate::common::exit_validator;
+use types::{BeaconStateError as Error, *};
+
+/// Iterate through the validator registry and eject active validators with balance below
+/// ``EJECTION_BALANCE``.
+///
+/// Spec v0.5.0
+pub fn process_ejections(state: &mut BeaconState, spec: &ChainSpec) -> Result<(), Error> {
+    // There is an awkward double (triple?) loop here because we can't loop across the borrowed
+    // active validator indices and mutate state in the one loop.
+    let exitable: Vec<usize> = state
+        .get_cached_active_validator_indices(RelativeEpoch::Current, spec)?
+        .iter()
+        .filter_map(|&i| {
+            if state.validator_balances[i as usize] < spec.ejection_balance {
+                Some(i)
+            } else {
+                None
+            }
+        })
+        .collect();
+
+    for validator_index in exitable {
+        exit_validator(state, validator_index, spec)?
+    }
+
+    Ok(())
+}

eth2/state_processing/src/per_epoch_processing/process_exit_queue.rs

@@ -0,0 +1,42 @@
+use types::*;
+
+/// Process the exit queue.
+///
+/// Spec v0.5.0
+pub fn process_exit_queue(state: &mut BeaconState, spec: &ChainSpec) {
+    let current_epoch = state.current_epoch(spec);
+
+    let eligible = |index: usize| {
+        let validator = &state.validator_registry[index];
+
+        if validator.withdrawable_epoch != spec.far_future_epoch {
+            false
+        } else {
+            current_epoch >= validator.exit_epoch + spec.min_validator_withdrawability_delay
+        }
+    };
+
+    let mut eligable_indices: Vec<usize> = (0..state.validator_registry.len())
+        .filter(|i| eligible(*i))
+        .collect();
+    eligable_indices.sort_by_key(|i| state.validator_registry[*i].exit_epoch);
+
+    for (dequeues, index) in eligable_indices.iter().enumerate() {
+        if dequeues as u64 >= spec.max_exit_dequeues_per_epoch {
+            break;
+        }
+        prepare_validator_for_withdrawal(state, *index, spec);
+    }
+}
+
+/// Initiate an exit for the validator of the given `index`.
+///
+/// Spec v0.5.0
+fn prepare_validator_for_withdrawal(
+    state: &mut BeaconState,
+    validator_index: usize,
+    spec: &ChainSpec,
+) {
+    state.validator_registry[validator_index].withdrawable_epoch =
+        state.current_epoch(spec) + spec.min_validator_withdrawability_delay;
+}

eth2/state_processing/src/per_epoch_processing/process_slashings.rs

@@ -0,0 +1,35 @@
+use types::{BeaconStateError as Error, *};
+
+/// Process slashings.
+///
+/// Spec v0.5.0
+pub fn process_slashings(
+    state: &mut BeaconState,
+    current_total_balance: u64,
+    spec: &ChainSpec,
+) -> Result<(), Error> {
+    let current_epoch = state.current_epoch(spec);
+
+    let total_at_start = state.get_slashed_balance(current_epoch + 1, spec)?;
+    let total_at_end = state.get_slashed_balance(current_epoch, spec)?;
+    let total_penalities = total_at_end - total_at_start;
+
+    for (index, validator) in state.validator_registry.iter().enumerate() {
+        let should_penalize = current_epoch.as_usize()
+            == validator.withdrawable_epoch.as_usize() - spec.latest_slashed_exit_length / 2;
+
+        if validator.slashed && should_penalize {
+            let effective_balance = state.get_effective_balance(index, spec)?;
+
+            let penalty = std::cmp::max(
+                effective_balance * std::cmp::min(total_penalities * 3, current_total_balance)
+                    / current_total_balance,
+                effective_balance / spec.min_penalty_quotient,
+            );
+
+            state.validator_balances[index] -= penalty;
+        }
+    }
+
+    Ok(())
+}

eth2/state_processing/src/per_epoch_processing/update_registry_and_shuffling_data.rs

@@ -0,0 +1,150 @@
+use super::super::common::exit_validator;
+use super::Error;
+use types::*;
+
+/// Peforms a validator registry update, if required.
+///
+/// Spec v0.5.0
+pub fn update_registry_and_shuffling_data(
+    state: &mut BeaconState,
+    current_total_balance: u64,
+    spec: &ChainSpec,
+) -> Result<(), Error> {
+    // First set previous shuffling data to current shuffling data.
+    state.previous_shuffling_epoch = state.current_shuffling_epoch;
+    state.previous_shuffling_start_shard = state.previous_shuffling_start_shard;
+    state.previous_shuffling_seed = state.previous_shuffling_seed;
+
+    let current_epoch = state.current_epoch(spec);
+    let next_epoch = current_epoch + 1;
+
+    // Check we should update, and if so, update.
+    if should_update_validator_registry(state, spec)? {
+        update_validator_registry(state, current_total_balance, spec)?;
+
+        // If we update the registry, update the shuffling data and shards as well.
+        state.current_shuffling_epoch = next_epoch;
+        state.current_shuffling_start_shard = {
+            let active_validators =
+                state.get_cached_active_validator_indices(RelativeEpoch::Current, spec)?;
+            let epoch_committee_count = spec.get_epoch_committee_count(active_validators.len());
+
+            (state.current_shuffling_start_shard + epoch_committee_count) % spec.shard_count
+        };
+        state.current_shuffling_seed = state.generate_seed(state.current_shuffling_epoch, spec)?;
+    } else {
+        // If processing at least on crosslink keeps failing, the reshuffle every power of two, but
+        // don't update the current_shuffling_start_shard.
+        let epochs_since_last_update = current_epoch - state.validator_registry_update_epoch;
+
+        if epochs_since_last_update > 1 && epochs_since_last_update.is_power_of_two() {
+            state.current_shuffling_epoch = next_epoch;
+            state.current_shuffling_seed =
+                state.generate_seed(state.current_shuffling_epoch, spec)?;
+        }
+    }
+
+    Ok(())
+}
+
+/// Returns `true` if the validator registry should be updated during an epoch processing.
+///
+/// Spec v0.5.0
+pub fn should_update_validator_registry(
+    state: &BeaconState,
+    spec: &ChainSpec,
+) -> Result<bool, BeaconStateError> {
+    if state.finalized_epoch <= state.validator_registry_update_epoch {
+        return Ok(false);
+    }
+
+    let num_active_validators = state
+        .get_cached_active_validator_indices(RelativeEpoch::Current, spec)?
+        .len();
+    let current_epoch_committee_count = spec.get_epoch_committee_count(num_active_validators);
+
+    for shard in (0..current_epoch_committee_count)
+        .map(|i| (state.current_shuffling_start_shard + i as u64) % spec.shard_count)
+    {
+        if state.latest_crosslinks[shard as usize].epoch <= state.validator_registry_update_epoch {
+            return Ok(false);
+        }
+    }
+
+    Ok(true)
+}
+
+/// Update validator registry, activating/exiting validators if possible.
+///
+/// Note: Utilizes the cache and will fail if the appropriate cache is not initialized.
+///
+/// Spec v0.5.0
+pub fn update_validator_registry(
+    state: &mut BeaconState,
+    current_total_balance: u64,
+    spec: &ChainSpec,
+) -> Result<(), Error> {
+    let current_epoch = state.current_epoch(spec);
+
+    let max_balance_churn = std::cmp::max(
+        spec.max_deposit_amount,
+        current_total_balance / (2 * spec.max_balance_churn_quotient),
+    );
+
+    // Activate validators within the allowable balance churn.
+    let mut balance_churn = 0;
+    for index in 0..state.validator_registry.len() {
+        let not_activated =
+            state.validator_registry[index].activation_epoch == spec.far_future_epoch;
+        let has_enough_balance = state.validator_balances[index] >= spec.max_deposit_amount;
+
+        if not_activated && has_enough_balance {
+            // Check the balance churn would be within the allowance.
+            balance_churn += state.get_effective_balance(index, spec)?;
+            if balance_churn > max_balance_churn {
+                break;
+            }
+
+            activate_validator(state, index, false, spec);
+        }
+    }
+
+    // Exit validators within the allowable balance churn.
+    let mut balance_churn = 0;
+    for index in 0..state.validator_registry.len() {
+        let not_exited = state.validator_registry[index].exit_epoch == spec.far_future_epoch;
+        let has_initiated_exit = state.validator_registry[index].initiated_exit;
+
+        if not_exited && has_initiated_exit {
+            // Check the balance churn would be within the allowance.
+            balance_churn += state.get_effective_balance(index, spec)?;
+            if balance_churn > max_balance_churn {
+                break;
+            }
+
+            exit_validator(state, index, spec)?;
+        }
+    }
+
+    state.validator_registry_update_epoch = current_epoch;
+
+    Ok(())
+}
+
+/// Activate the validator of the given ``index``.
+///
+/// Spec v0.5.0
+pub fn activate_validator(
+    state: &mut BeaconState,
+    validator_index: usize,
+    is_genesis: bool,
+    spec: &ChainSpec,
+) {
+    let current_epoch = state.current_epoch(spec);
+
+    state.validator_registry[validator_index].activation_epoch = if is_genesis {
+        spec.genesis_epoch
+    } else {
+        state.get_delayed_activation_exit_epoch(current_epoch, spec)
+    }
+}

eth2/state_processing/src/per_epoch_processing/validator_statuses.rs

@@ -1,3 +1,4 @@
+use super::get_attestation_participants::get_attestation_participants;
 use super::WinningRootHashSet;
 use types::*;
 
@@ -22,7 +23,7 @@ pub struct WinningRootInfo {
 }
 
 /// The information required to reward a block producer for including an attestation in a block.
-#[derive(Clone)]
+#[derive(Clone, Copy)]
 pub struct InclusionInfo {
     /// The earliest slot a validator had an attestation included in the previous epoch.
     pub slot: Slot,
@@ -58,7 +59,11 @@ impl InclusionInfo {
 
 /// Information required to reward some validator during the current and previous epoch.
 #[derive(Default, Clone)]
-pub struct AttesterStatus {
+pub struct ValidatorStatus {
+    /// True if the validator has been slashed, ever.
+    pub is_slashed: bool,
+    /// True if the validator can withdraw in the current epoch.
+    pub is_withdrawable_in_current_epoch: bool,
     /// True if the validator was active in the state's _current_ epoch.
     pub is_active_in_current_epoch: bool,
     /// True if the validator was active in the state's _previous_ epoch.
@@ -80,14 +85,14 @@ pub struct AttesterStatus {
 
     /// Information used to reward the block producer of this validators earliest-included
     /// attestation.
-    pub inclusion_info: InclusionInfo,
+    pub inclusion_info: Option<InclusionInfo>,
     /// Information used to reward/penalize the validator if they voted in the super-majority for
     /// some shard block.
     pub winning_root_info: Option<WinningRootInfo>,
 }
 
-impl AttesterStatus {
+impl ValidatorStatus {
-    /// Accepts some `other` `AttesterStatus` and updates `self` if required.
+    /// Accepts some `other` `ValidatorStatus` and updates `self` if required.
     ///
     /// Will never set one of the `bool` fields to `false`, it will only set it to `true` if other
     /// contains a `true` field.
@@ -96,6 +101,8 @@ impl AttesterStatus {
     pub fn update(&mut self, other: &Self) {
         // Update all the bool fields, only updating `self` if `other` is true (never setting
         // `self` to false).
+        set_self_if_other_is_true!(self, other, is_slashed);
+        set_self_if_other_is_true!(self, other, is_withdrawable_in_current_epoch);
         set_self_if_other_is_true!(self, other, is_active_in_current_epoch);
         set_self_if_other_is_true!(self, other, is_active_in_previous_epoch);
         set_self_if_other_is_true!(self, other, is_current_epoch_attester);
@@ -104,7 +111,13 @@ impl AttesterStatus {
         set_self_if_other_is_true!(self, other, is_previous_epoch_boundary_attester);
         set_self_if_other_is_true!(self, other, is_previous_epoch_head_attester);
 
-        self.inclusion_info.update(&other.inclusion_info);
+        if let Some(other_info) = other.inclusion_info {
+            if let Some(self_info) = self.inclusion_info.as_mut() {
+                self_info.update(&other_info);
+            } else {
+                self.inclusion_info = other.inclusion_info;
+            }
+        }
     }
 }
 
@@ -136,7 +149,7 @@ pub struct TotalBalances {
 #[derive(Clone)]
 pub struct ValidatorStatuses {
     /// Information about each individual validator from the state's validator registy.
-    pub statuses: Vec<AttesterStatus>,
+    pub statuses: Vec<ValidatorStatus>,
     /// Summed balances for various sets of validators.
     pub total_balances: TotalBalances,
 }
@@ -147,52 +160,60 @@ impl ValidatorStatuses {
     /// - Active validators
     /// - Total balances for the current and previous epochs.
     ///
-    /// Spec v0.4.0
+    /// Spec v0.5.0
-    pub fn new(state: &BeaconState, spec: &ChainSpec) -> Self {
+    pub fn new(state: &BeaconState, spec: &ChainSpec) -> Result<Self, BeaconStateError> {
         let mut statuses = Vec::with_capacity(state.validator_registry.len());
         let mut total_balances = TotalBalances::default();
 
         for (i, validator) in state.validator_registry.iter().enumerate() {
-            let mut status = AttesterStatus::default();
+            let mut status = ValidatorStatus {
+                is_slashed: validator.slashed,
+                is_withdrawable_in_current_epoch: validator
+                    .is_withdrawable_at(state.current_epoch(spec)),
+                ..ValidatorStatus::default()
+            };
 
             if validator.is_active_at(state.current_epoch(spec)) {
                 status.is_active_in_current_epoch = true;
-                total_balances.current_epoch += state.get_effective_balance(i, spec);
+                total_balances.current_epoch += state.get_effective_balance(i, spec)?;
             }
 
             if validator.is_active_at(state.previous_epoch(spec)) {
                 status.is_active_in_previous_epoch = true;
-                total_balances.previous_epoch += state.get_effective_balance(i, spec);
+                total_balances.previous_epoch += state.get_effective_balance(i, spec)?;
             }
 
             statuses.push(status);
         }
 
-        Self {
+        Ok(Self {
             statuses,
             total_balances,
-        }
+        })
     }
 
     /// Process some attestations from the given `state` updating the `statuses` and
     /// `total_balances` fields.
     ///
-    /// Spec v0.4.0
+    /// Spec v0.5.0
     pub fn process_attestations(
         &mut self,
         state: &BeaconState,
-        attestations: &[PendingAttestation],
         spec: &ChainSpec,
     ) -> Result<(), BeaconStateError> {
-        for a in attestations {
+        for a in state
+            .previous_epoch_attestations
+            .iter()
+            .chain(state.current_epoch_attestations.iter())
+        {
             let attesting_indices =
-                state.get_attestation_participants(&a.data, &a.aggregation_bitfield, spec)?;
+                get_attestation_participants(state, &a.data, &a.aggregation_bitfield, spec)?;
-            let attesting_balance = state.get_total_balance(&attesting_indices, spec);
+            let attesting_balance = state.get_total_balance(&attesting_indices, spec)?;
 
-            let mut status = AttesterStatus::default();
+            let mut status = ValidatorStatus::default();
 
             // Profile this attestation, updating the total balances and generating an
-            // `AttesterStatus` object that applies to all participants in the attestation.
+            // `ValidatorStatus` object that applies to all participants in the attestation.
             if is_from_epoch(a, state.current_epoch(spec), spec) {
                 self.total_balances.current_epoch_attesters += attesting_balance;
                 status.is_current_epoch_attester = true;
@@ -206,11 +227,16 @@ impl ValidatorStatuses {
                 status.is_previous_epoch_attester = true;
 
                 // The inclusion slot and distance are only required for previous epoch attesters.
-                status.inclusion_info = InclusionInfo {
+                let relative_epoch = RelativeEpoch::from_slot(state.slot, a.data.slot, spec)?;
+                status.inclusion_info = Some(InclusionInfo {
                     slot: a.inclusion_slot,
                     distance: inclusion_distance(a),
-                    proposer_index: state.get_beacon_proposer_index(a.inclusion_slot, spec)?,
+                    proposer_index: state.get_beacon_proposer_index(
-                };
+                        a.inclusion_slot,
+                        relative_epoch,
+                        spec,
+                    )?,
+                });
 
                 if has_common_epoch_boundary_root(a, state, state.previous_epoch(spec), spec)? {
                     self.total_balances.previous_epoch_boundary_attesters += attesting_balance;
@@ -235,7 +261,7 @@ impl ValidatorStatuses {
     /// Update the `statuses` for each validator based upon whether or not they attested to the
     /// "winning" shard block root for the previous epoch.
     ///
-    /// Spec v0.4.0
+    /// Spec v0.5.0
     pub fn process_winning_roots(
         &mut self,
         state: &BeaconState,
@@ -248,11 +274,10 @@ impl ValidatorStatuses {
                 state.get_crosslink_committees_at_slot(slot, spec)?;
 
             // Loop through each committee in the slot.
-            for (crosslink_committee, shard) in crosslink_committees_at_slot {
+            for c in crosslink_committees_at_slot {
                 // If there was some winning crosslink root for the committee's shard.
-                if let Some(winning_root) = winning_roots.get(&shard) {
+                if let Some(winning_root) = winning_roots.get(&c.shard) {
-                    let total_committee_balance =
+                    let total_committee_balance = state.get_total_balance(&c.committee, spec)?;
-                        state.get_total_balance(&crosslink_committee, spec);
                     for &validator_index in &winning_root.attesting_validator_indices {
                         // Take note of the balance information for the winning root, it will be
                         // used later to calculate rewards for that validator.
@@ -272,14 +297,14 @@ impl ValidatorStatuses {
 /// Returns the distance between when the attestation was created and when it was included in a
 /// block.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 fn inclusion_distance(a: &PendingAttestation) -> Slot {
     a.inclusion_slot - a.data.slot
 }
 
 /// Returns `true` if some `PendingAttestation` is from the supplied `epoch`.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 fn is_from_epoch(a: &PendingAttestation, epoch: Epoch, spec: &ChainSpec) -> bool {
     a.data.slot.epoch(spec.slots_per_epoch) == epoch
 }
@@ -287,7 +312,7 @@ fn is_from_epoch(a: &PendingAttestation, epoch: Epoch, spec: &ChainSpec) -> bool
 /// Returns `true` if a `PendingAttestation` and `BeaconState` share the same beacon block hash for
 /// the first slot of the given epoch.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 fn has_common_epoch_boundary_root(
     a: &PendingAttestation,
     state: &BeaconState,
@@ -295,25 +320,21 @@ fn has_common_epoch_boundary_root(
     spec: &ChainSpec,
 ) -> Result<bool, BeaconStateError> {
     let slot = epoch.start_slot(spec.slots_per_epoch);
-    let state_boundary_root = *state
+    let state_boundary_root = *state.get_block_root(slot, spec)?;
-        .get_block_root(slot, spec)
-        .ok_or_else(|| BeaconStateError::InsufficientBlockRoots)?;
 
-    Ok(a.data.epoch_boundary_root == state_boundary_root)
+    Ok(a.data.target_root == state_boundary_root)
 }
 
 /// Returns `true` if a `PendingAttestation` and `BeaconState` share the same beacon block hash for
 /// the current slot of the `PendingAttestation`.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 fn has_common_beacon_block_root(
     a: &PendingAttestation,
     state: &BeaconState,
     spec: &ChainSpec,
 ) -> Result<bool, BeaconStateError> {
-    let state_block_root = *state
+    let state_block_root = *state.get_block_root(a.data.slot, spec)?;
-        .get_block_root(a.data.slot, spec)
-        .ok_or_else(|| BeaconStateError::InsufficientBlockRoots)?;
 
     Ok(a.data.beacon_block_root == state_block_root)
 }

eth2/state_processing/src/per_epoch_processing/winning_root.rs

@@ -1,3 +1,4 @@
+use super::get_attestation_participants::get_attestation_participants;
 use std::collections::HashSet;
 use std::iter::FromIterator;
 use types::*;
@@ -13,14 +14,14 @@ impl WinningRoot {
     /// Returns `true` if `self` is a "better" candidate than `other`.
     ///
     /// A winning root is "better" than another if it has a higher `total_attesting_balance`. Ties
-    /// are broken by favouring the lower `crosslink_data_root` value.
+    /// are broken by favouring the higher `crosslink_data_root` value.
     ///
-    /// Spec v0.4.0
+    /// Spec v0.5.0
     pub fn is_better_than(&self, other: &Self) -> bool {
         if self.total_attesting_balance > other.total_attesting_balance {
             true
         } else if self.total_attesting_balance == other.total_attesting_balance {
-            self.crosslink_data_root < other.crosslink_data_root
+            self.crosslink_data_root > other.crosslink_data_root
         } else {
             false
         }
@@ -33,22 +34,21 @@ impl WinningRoot {
 /// The `WinningRoot` object also contains additional fields that are useful in later stages of
 /// per-epoch processing.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 pub fn winning_root(
     state: &BeaconState,
     shard: u64,
-    current_epoch_attestations: &[&PendingAttestation],
-    previous_epoch_attestations: &[&PendingAttestation],
     spec: &ChainSpec,
 ) -> Result<Option<WinningRoot>, BeaconStateError> {
     let mut winning_root: Option<WinningRoot> = None;
 
     let crosslink_data_roots: HashSet<Hash256> = HashSet::from_iter(
-        previous_epoch_attestations
+        state
+            .previous_epoch_attestations
             .iter()
-            .chain(current_epoch_attestations.iter())
+            .chain(state.current_epoch_attestations.iter())
             .filter_map(|a| {
-                if a.data.shard == shard {
+                if is_eligible_for_winning_root(state, a, shard) {
                     Some(a.data.crosslink_data_root)
                 } else {
                     None
@@ -57,18 +57,17 @@ pub fn winning_root(
     );
 
     for crosslink_data_root in crosslink_data_roots {
-        let attesting_validator_indices = get_attesting_validator_indices(
+        let attesting_validator_indices =
-            state,
+            get_attesting_validator_indices(state, shard, &crosslink_data_root, spec)?;
-            shard,
-            current_epoch_attestations,
-            previous_epoch_attestations,
-            &crosslink_data_root,
-            spec,
-        )?;
 
-        let total_attesting_balance: u64 = attesting_validator_indices
+        let total_attesting_balance: u64 =
+            attesting_validator_indices
                 .iter()
-            .fold(0, |acc, i| acc + state.get_effective_balance(*i, spec));
+                .try_fold(0_u64, |acc, i| {
+                    state
+                        .get_effective_balance(*i, spec)
+                        .and_then(|bal| Ok(acc + bal))
+                })?;
 
         let candidate = WinningRoot {
             crosslink_data_root,
@@ -88,25 +87,36 @@ pub fn winning_root(
     Ok(winning_root)
 }
 
-/// Returns all indices which voted for a given crosslink. May contain duplicates.
+/// Returns `true` if pending attestation `a` is eligible to become a winning root.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
+fn is_eligible_for_winning_root(state: &BeaconState, a: &PendingAttestation, shard: Shard) -> bool {
+    if shard >= state.latest_crosslinks.len() as u64 {
+        return false;
+    }
+
+    a.data.previous_crosslink == state.latest_crosslinks[shard as usize]
+}
+
+/// Returns all indices which voted for a given crosslink. Does not contain duplicates.
+///
+/// Spec v0.5.0
 fn get_attesting_validator_indices(
     state: &BeaconState,
     shard: u64,
-    current_epoch_attestations: &[&PendingAttestation],
-    previous_epoch_attestations: &[&PendingAttestation],
     crosslink_data_root: &Hash256,
     spec: &ChainSpec,
 ) -> Result<Vec<usize>, BeaconStateError> {
     let mut indices = vec![];
 
-    for a in current_epoch_attestations
+    for a in state
+        .current_epoch_attestations
         .iter()
-        .chain(previous_epoch_attestations.iter())
+        .chain(state.previous_epoch_attestations.iter())
     {
         if (a.data.shard == shard) && (a.data.crosslink_data_root == *crosslink_data_root) {
-            indices.append(&mut state.get_attestation_participants(
+            indices.append(&mut get_attestation_participants(
+                state,
                 &a.data,
                 &a.aggregation_bitfield,
                 spec,
@@ -114,5 +124,41 @@ fn get_attesting_validator_indices(
         }
     }
 
+    // Sort the list (required for dedup). "Unstable" means the sort may re-order equal elements,
+    // this causes no issue here.
+    //
+    // These sort + dedup ops are potentially good CPU time optimisation targets.
+    indices.sort_unstable();
+    // Remove all duplicate indices (requires a sorted list).
+    indices.dedup();
+
     Ok(indices)
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn is_better_than() {
+        let worse = WinningRoot {
+            crosslink_data_root: Hash256::from_slice(&[1; 32]),
+            attesting_validator_indices: vec![],
+            total_attesting_balance: 42,
+        };
+
+        let better = WinningRoot {
+            crosslink_data_root: Hash256::from_slice(&[2; 32]),
+            ..worse.clone()
+        };
+
+        assert!(better.is_better_than(&worse));
+
+        let better = WinningRoot {
+            total_attesting_balance: worse.total_attesting_balance + 1,
+            ..worse.clone()
+        };
+
+        assert!(better.is_better_than(&worse));
+    }
+}

eth2/state_processing/src/per_slot_processing.rs

@@ -1,5 +1,6 @@
 use crate::*;
-use types::{BeaconState, BeaconStateError, ChainSpec, Hash256};
+use ssz::TreeHash;
+use types::*;
 
 #[derive(Debug, PartialEq)]
 pub enum Error {
@@ -9,12 +10,14 @@ pub enum Error {
 
 /// Advances a state forward by one slot, performing per-epoch processing if required.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 pub fn per_slot_processing(
     state: &mut BeaconState,
-    previous_block_root: Hash256,
+    latest_block_header: &BeaconBlockHeader,
     spec: &ChainSpec,
 ) -> Result<(), Error> {
+    cache_state(state, latest_block_header, spec)?;
+
     if (state.slot + 1) % spec.slots_per_epoch == 0 {
         per_epoch_processing(state, spec)?;
         state.advance_caches();
@@ -22,27 +25,35 @@ pub fn per_slot_processing(
 
     state.slot += 1;
 
-    update_block_roots(state, previous_block_root, spec);
-
     Ok(())
 }
 
-/// Updates the state's block roots as per-slot processing is performed.
+fn cache_state(
-///
+    state: &mut BeaconState,
-/// Spec v0.4.0
+    latest_block_header: &BeaconBlockHeader,
-pub fn update_block_roots(state: &mut BeaconState, previous_block_root: Hash256, spec: &ChainSpec) {
+    spec: &ChainSpec,
-    state.latest_block_roots[(state.slot.as_usize() - 1) % spec.latest_block_roots_length] =
+) -> Result<(), Error> {
-        previous_block_root;
+    let previous_slot_state_root = Hash256::from_slice(&state.hash_tree_root()[..]);
 
-    if state.slot.as_usize() % spec.latest_block_roots_length == 0 {
+    // Note: increment the state slot here to allow use of our `state_root` and `block_root`
-        let root = merkle_root(&state.latest_block_roots[..]);
+    // getter/setter functions.
-        state.batched_block_roots.push(root);
+    //
-    }
+    // This is a bit hacky, however it gets the job safely without lots of code.
+    let previous_slot = state.slot;
+    state.slot += 1;
+
+    // Store the previous slot's post-state transition root.
+    if state.latest_block_header.state_root == spec.zero_hash {
+        state.latest_block_header.state_root = previous_slot_state_root
     }
 
-fn merkle_root(_input: &[Hash256]) -> Hash256 {
+    let latest_block_root = Hash256::from_slice(&latest_block_header.hash_tree_root()[..]);
-    // TODO: implement correctly.
+    state.set_block_root(previous_slot, latest_block_root, spec)?;
-    Hash256::zero()
+
+    // Set the state slot back to what it should be.
+    state.slot -= 1;
+
+    Ok(())
 }
 
 impl From<BeaconStateError> for Error {

eth2/state_processing/tests/tests.rs

@@ -0,0 +1,42 @@
+use serde_derive::Deserialize;
+use types::*;
+
+#[derive(Debug, Deserialize)]
+pub struct TestCase {
+    pub name: String,
+    pub config: ChainSpec,
+    pub verify_signatures: bool,
+    pub initial_state: BeaconState,
+    pub blocks: Vec<BeaconBlock>,
+}
+
+#[derive(Debug, Deserialize)]
+pub struct TestDoc {
+    pub title: String,
+    pub summary: String,
+    pub fork: String,
+    pub version: String,
+    pub test_cases: Vec<TestCase>,
+}
+
+#[test]
+#[ignore]
+fn yaml() {
+    use serde_yaml;
+    use std::{fs::File, io::prelude::*, path::PathBuf};
+
+    let mut file = {
+        let mut file_path_buf = PathBuf::from(env!("CARGO_MANIFEST_DIR"));
+        file_path_buf.push("specs/example.yml");
+
+        File::open(file_path_buf).unwrap()
+    };
+
+    let mut yaml_str = String::new();
+
+    file.read_to_string(&mut yaml_str).unwrap();
+
+    let yaml_str = yaml_str.to_lowercase();
+
+    let _doc: TestDoc = serde_yaml::from_str(&yaml_str.as_str()).unwrap();
+}

eth2/types/src/attestation.rs

@@ -1,15 +1,26 @@
 use super::{AggregateSignature, AttestationData, Bitfield};
 use crate::test_utils::TestRandom;
 use rand::RngCore;
-use serde_derive::Serialize;
+use serde_derive::{Deserialize, Serialize};
 use ssz::TreeHash;
 use ssz_derive::{Decode, Encode, SignedRoot, TreeHash};
 use test_random_derive::TestRandom;
 
 /// Details an attestation that can be slashable.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
-#[derive(Debug, Clone, PartialEq, Serialize, Encode, Decode, TreeHash, TestRandom, SignedRoot)]
+#[derive(
+    Debug,
+    Clone,
+    PartialEq,
+    Serialize,
+    Deserialize,
+    Encode,
+    Decode,
+    TreeHash,
+    TestRandom,
+    SignedRoot,
+)]
 pub struct Attestation {
     pub aggregation_bitfield: Bitfield,
     pub data: AttestationData,

eth2/types/src/attestation_data.rs

@@ -1,20 +1,21 @@
 use crate::test_utils::TestRandom;
 use crate::{Crosslink, Epoch, Hash256, Slot};
 use rand::RngCore;
-use serde_derive::Serialize;
+use serde_derive::{Deserialize, Serialize};
 use ssz::TreeHash;
 use ssz_derive::{Decode, Encode, SignedRoot, TreeHash};
 use test_random_derive::TestRandom;
 
 /// The data upon which an attestation is based.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 #[derive(
     Debug,
     Clone,
     PartialEq,
     Default,
     Serialize,
+    Deserialize,
     Hash,
     Encode,
     Decode,
@@ -23,14 +24,19 @@ use test_random_derive::TestRandom;
     SignedRoot,
 )]
 pub struct AttestationData {
+    // LMD GHOST vote
     pub slot: Slot,
-    pub shard: u64,
     pub beacon_block_root: Hash256,
-    pub epoch_boundary_root: Hash256,
+
+    // FFG Vote
+    pub source_epoch: Epoch,
+    pub source_root: Hash256,
+    pub target_root: Hash256,
+
+    // Crosslink Vote
+    pub shard: u64,
+    pub previous_crosslink: Crosslink,
     pub crosslink_data_root: Hash256,
-    pub latest_crosslink: Crosslink,
-    pub justified_epoch: Epoch,
-    pub justified_block_root: Hash256,
 }
 
 impl Eq for AttestationData {}

eth2/types/src/attestation_data_and_custody_bit.rs

@@ -6,7 +6,7 @@ use ssz_derive::{Decode, Encode, TreeHash};
 
 /// Used for pairing an attestation with a proof-of-custody.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 #[derive(Debug, Clone, PartialEq, Default, Serialize, Encode, Decode, TreeHash)]
 pub struct AttestationDataAndCustodyBit {
     pub data: AttestationData,

eth2/types/src/attestation_duty.rs

@@ -0,0 +1,9 @@
+use crate::*;
+use serde_derive::{Deserialize, Serialize};
+
+#[derive(Debug, PartialEq, Clone, Default, Serialize, Deserialize)]
+pub struct AttestationDuty {
+    pub slot: Slot,
+    pub shard: Shard,
+    pub committee_index: usize,
+}

eth2/types/src/attester_slashing.rs

@@ -1,13 +1,13 @@
 use crate::{test_utils::TestRandom, SlashableAttestation};
 use rand::RngCore;
-use serde_derive::Serialize;
+use serde_derive::{Deserialize, Serialize};
 use ssz_derive::{Decode, Encode, TreeHash};
 use test_random_derive::TestRandom;
 
 /// Two conflicting attestations.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
-#[derive(Debug, PartialEq, Clone, Serialize, Encode, Decode, TreeHash, TestRandom)]
+#[derive(Debug, PartialEq, Clone, Serialize, Deserialize, Encode, Decode, TreeHash, TestRandom)]
 pub struct AttesterSlashing {
     pub slashable_attestation_1: SlashableAttestation,
     pub slashable_attestation_2: SlashableAttestation,

eth2/types/src/beacon_block.rs

@@ -1,41 +1,50 @@
 use crate::test_utils::TestRandom;
-use crate::{BeaconBlockBody, ChainSpec, Eth1Data, Hash256, Proposal, Slot};
+use crate::*;
 use bls::Signature;
 use rand::RngCore;
-use serde_derive::Serialize;
+use serde_derive::{Deserialize, Serialize};
-use ssz::{SignedRoot, TreeHash};
+use ssz::TreeHash;
 use ssz_derive::{Decode, Encode, SignedRoot, TreeHash};
 use test_random_derive::TestRandom;
 
 /// A block of the `BeaconChain`.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
-#[derive(Debug, PartialEq, Clone, Serialize, Encode, Decode, TreeHash, TestRandom, SignedRoot)]
+#[derive(
+    Debug,
+    PartialEq,
+    Clone,
+    Serialize,
+    Deserialize,
+    Encode,
+    Decode,
+    TreeHash,
+    TestRandom,
+    SignedRoot,
+)]
 pub struct BeaconBlock {
     pub slot: Slot,
-    pub parent_root: Hash256,
+    pub previous_block_root: Hash256,
     pub state_root: Hash256,
-    pub randao_reveal: Signature,
-    pub eth1_data: Eth1Data,
     pub body: BeaconBlockBody,
     pub signature: Signature,
 }
 
 impl BeaconBlock {
-    /// Produce the first block of the Beacon Chain.
+    /// Returns an empty block to be used during genesis.
     ///
-    /// Spec v0.4.0
+    /// Spec v0.5.0
-    pub fn genesis(state_root: Hash256, spec: &ChainSpec) -> BeaconBlock {
+    pub fn empty(spec: &ChainSpec) -> BeaconBlock {
         BeaconBlock {
             slot: spec.genesis_slot,
-            parent_root: spec.zero_hash,
+            previous_block_root: spec.zero_hash,
-            state_root,
+            state_root: spec.zero_hash,
+            body: BeaconBlockBody {
                 randao_reveal: spec.empty_signature.clone(),
                 eth1_data: Eth1Data {
                     deposit_root: spec.zero_hash,
                     block_hash: spec.zero_hash,
                 },
-            body: BeaconBlockBody {
                 proposer_slashings: vec![],
                 attester_slashings: vec![],
                 attestations: vec![],
@@ -49,20 +58,37 @@ impl BeaconBlock {
 
     /// Returns the `hash_tree_root` of the block.
     ///
-    /// Spec v0.4.0
+    /// Spec v0.5.0
     pub fn canonical_root(&self) -> Hash256 {
         Hash256::from_slice(&self.hash_tree_root()[..])
     }
 
-    /// Returns an unsigned proposal for block.
+    /// Returns a full `BeaconBlockHeader` of this block.
     ///
-    /// Spec v0.4.0
+    /// Note: This method is used instead of an `Into` impl to avoid a `Clone` of an entire block
-    pub fn proposal(&self, spec: &ChainSpec) -> Proposal {
+    /// when you want to have the block _and_ the header.
-        Proposal {
+    ///
+    /// Note: performs a full tree-hash of `self.body`.
+    ///
+    /// Spec v0.5.0
+    pub fn block_header(&self) -> BeaconBlockHeader {
+        BeaconBlockHeader {
             slot: self.slot,
-            shard: spec.beacon_chain_shard_number,
+            previous_block_root: self.previous_block_root,
-            block_root: Hash256::from_slice(&self.signed_root()),
+            state_root: self.state_root,
+            block_body_root: Hash256::from_slice(&self.body.hash_tree_root()[..]),
+            signature: self.signature.clone(),
+        }
+    }
+
+    /// Returns a "temporary" header, where the `state_root` is `spec.zero_hash`.
+    ///
+    /// Spec v0.5.0
+    pub fn temporary_block_header(&self, spec: &ChainSpec) -> BeaconBlockHeader {
+        BeaconBlockHeader {
+            state_root: spec.zero_hash,
             signature: spec.empty_signature.clone(),
+            ..self.block_header()
         }
     }
 }

eth2/types/src/beacon_block_body.rs

@@ -1,15 +1,17 @@
-use super::{Attestation, AttesterSlashing, Deposit, ProposerSlashing, Transfer, VoluntaryExit};
 use crate::test_utils::TestRandom;
+use crate::*;
 use rand::RngCore;
-use serde_derive::Serialize;
+use serde_derive::{Deserialize, Serialize};
 use ssz_derive::{Decode, Encode, TreeHash};
 use test_random_derive::TestRandom;
 
 /// The body of a `BeaconChain` block, containing operations.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
-#[derive(Debug, PartialEq, Clone, Default, Serialize, Encode, Decode, TreeHash, TestRandom)]
+#[derive(Debug, PartialEq, Clone, Serialize, Deserialize, Encode, Decode, TreeHash, TestRandom)]
 pub struct BeaconBlockBody {
+    pub randao_reveal: Signature,
+    pub eth1_data: Eth1Data,
     pub proposer_slashings: Vec<ProposerSlashing>,
     pub attester_slashings: Vec<AttesterSlashing>,
     pub attestations: Vec<Attestation>,

eth2/types/src/beacon_block_header.rs

@@ -0,0 +1,47 @@
+use crate::test_utils::TestRandom;
+use crate::*;
+use bls::Signature;
+use rand::RngCore;
+use serde_derive::{Deserialize, Serialize};
+use ssz::TreeHash;
+use ssz_derive::{Decode, Encode, SignedRoot, TreeHash};
+use test_random_derive::TestRandom;
+
+/// A header of a `BeaconBlock`.
+///
+/// Spec v0.5.0
+#[derive(
+    Debug,
+    PartialEq,
+    Clone,
+    Serialize,
+    Deserialize,
+    Encode,
+    Decode,
+    TreeHash,
+    TestRandom,
+    SignedRoot,
+)]
+pub struct BeaconBlockHeader {
+    pub slot: Slot,
+    pub previous_block_root: Hash256,
+    pub state_root: Hash256,
+    pub block_body_root: Hash256,
+    pub signature: Signature,
+}
+
+impl BeaconBlockHeader {
+    /// Returns the `hash_tree_root` of the header.
+    ///
+    /// Spec v0.5.0
+    pub fn canonical_root(&self) -> Hash256 {
+        Hash256::from_slice(&self.hash_tree_root()[..])
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    ssz_tests!(BeaconBlockHeader);
+}

eth2/types/src/beacon_state/builder.rs

@@ -1,99 +0,0 @@
-use super::BeaconStateError;
-use crate::validator_registry::get_active_validator_indices;
-use crate::*;
-use rayon::prelude::*;
-use ssz::TreeHash;
-
-/// Builds a `BeaconState` for use in production.
-///
-/// This struct should _not_ be modified for use in testing scenarios. Use `TestingBeaconStateBuilder` for that purpose.
-///
-/// This struct should remain safe and sensible for production usage.
-pub struct BeaconStateBuilder {
-    pub state: BeaconState,
-}
-
-impl BeaconStateBuilder {
-    /// Create a new builder with the given number of validators.
-    ///
-    /// Spec v0.4.0
-    pub fn new(genesis_time: u64, latest_eth1_data: Eth1Data, spec: &ChainSpec) -> Self {
-        Self {
-            state: BeaconState::genesis(genesis_time, latest_eth1_data, spec),
-        }
-    }
-
-    /// Process deposit objects.
-    ///
-    /// Spec v0.4.0
-    pub fn process_initial_deposits(
-        &mut self,
-        initial_validator_deposits: &[Deposit],
-        spec: &ChainSpec,
-    ) {
-        let deposit_data = initial_validator_deposits
-            .par_iter()
-            .map(|deposit| &deposit.deposit_data)
-            .collect();
-
-        self.state.process_deposits(deposit_data, spec);
-
-        self.activate_genesis_validators(spec);
-
-        self.state.deposit_index = initial_validator_deposits.len() as u64;
-    }
-
-    fn activate_genesis_validators(&mut self, spec: &ChainSpec) {
-        for validator_index in 0..self.state.validator_registry.len() {
-            if self.state.get_effective_balance(validator_index, spec) >= spec.max_deposit_amount {
-                self.state.activate_validator(validator_index, true, spec);
-            }
-        }
-    }
-
-    /// Instantiate the validator registry from a YAML file.
-    ///
-    /// This skips a lot of signing and verification, useful if signing and verification has been
-    /// completed previously.
-    ///
-    /// Spec v0.4.0
-    pub fn import_existing_validators(
-        &mut self,
-        validators: Vec<Validator>,
-        initial_balances: Vec<u64>,
-        deposit_index: u64,
-        spec: &ChainSpec,
-    ) {
-        self.state.validator_registry = validators;
-
-        assert_eq!(
-            self.state.validator_registry.len(),
-            initial_balances.len(),
-            "Not enough balances for validators"
-        );
-
-        self.state.validator_balances = initial_balances;
-
-        self.activate_genesis_validators(spec);
-
-        self.state.deposit_index = deposit_index;
-    }
-
-    /// Updates the final state variables and returns a fully built genesis state.
-    ///
-    /// Spec v0.4.0
-    pub fn build(mut self, spec: &ChainSpec) -> Result<BeaconState, BeaconStateError> {
-        let genesis_active_index_root =
-            get_active_validator_indices(&self.state.validator_registry, spec.genesis_epoch)
-                .hash_tree_root();
-
-        self.state.latest_active_index_roots = vec![
-            Hash256::from_slice(&genesis_active_index_root);
-            spec.latest_active_index_roots_length
-        ];
-
-        self.state.current_shuffling_seed = self.state.generate_seed(spec.genesis_epoch, spec)?;
-
-        Ok(self.state)
-    }
-}

eth2/types/src/beacon_state/epoch_cache.rs

@@ -1,84 +1,324 @@
-use super::{AttestationDutyMap, BeaconState, CrosslinkCommittees, Error, ShardCommitteeIndexMap};
+use super::BeaconState;
-use crate::{ChainSpec, Epoch};
+use crate::*;
-use log::trace;
+use honey_badger_split::SplitExt;
-use serde_derive::Serialize;
+use serde_derive::{Deserialize, Serialize};
-use std::collections::HashMap;
+use swap_or_not_shuffle::shuffle_list;
 
-#[derive(Debug, PartialEq, Clone, Serialize)]
+#[derive(Debug, PartialEq)]
+pub enum Error {
+    UnableToShuffle,
+    UnableToGenerateSeed,
+}
+
+mod tests;
+
+#[derive(Debug, Default, PartialEq, Clone, Serialize, Deserialize)]
 pub struct EpochCache {
-    /// True if this cache has been initialized.
+    /// `Some(epoch)` if the cache is initialized, where `epoch` is the cache it holds.
-    pub initialized: bool,
+    pub initialized_epoch: Option<Epoch>,
-    /// The crosslink committees for an epoch.
+    /// All crosslink committees for an epoch.
-    pub committees: Vec<CrosslinkCommittees>,
+    pub epoch_crosslink_committees: EpochCrosslinkCommittees,
     /// Maps validator index to a slot, shard and committee index for attestation.
-    pub attestation_duty_map: AttestationDutyMap,
+    pub attestation_duties: Vec<Option<AttestationDuty>>,
     /// Maps a shard to an index of `self.committees`.
-    pub shard_committee_index_map: ShardCommitteeIndexMap,
+    pub shard_committee_indices: Vec<Option<(Slot, usize)>>,
+    /// Indices of all active validators in the epoch
+    pub active_validator_indices: Vec<usize>,
 }
 
 impl EpochCache {
-    pub fn empty() -> EpochCache {
+    /// Return a new, fully initialized cache.
-        EpochCache {
-            initialized: false,
-            committees: vec![],
-            attestation_duty_map: AttestationDutyMap::new(),
-            shard_committee_index_map: ShardCommitteeIndexMap::new(),
-        }
-    }
-
     pub fn initialized(
         state: &BeaconState,
-        epoch: Epoch,
+        relative_epoch: RelativeEpoch,
         spec: &ChainSpec,
     ) -> Result<EpochCache, Error> {
-        let mut epoch_committees: Vec<CrosslinkCommittees> =
+        let epoch = relative_epoch.into_epoch(state.slot.epoch(spec.slots_per_epoch));
-            Vec::with_capacity(spec.slots_per_epoch as usize);
-        let mut attestation_duty_map: AttestationDutyMap = HashMap::new();
-        let mut shard_committee_index_map: ShardCommitteeIndexMap = HashMap::new();
 
-        let shuffling =
+        let active_validator_indices =
-            state.get_shuffling_for_slot(epoch.start_slot(spec.slots_per_epoch), false, spec)?;
+            get_active_validator_indices(&state.validator_registry, epoch);
 
-        for (epoch_committeess_index, slot) in epoch.slot_iter(spec.slots_per_epoch).enumerate() {
+        let builder = match relative_epoch {
-            let slot_committees = state.calculate_crosslink_committees_at_slot(
+            RelativeEpoch::Previous => EpochCrosslinkCommitteesBuilder::for_previous_epoch(
-                slot,
+                state,
-                false,
+                active_validator_indices.clone(),
-                shuffling.clone(),
                 spec,
-            )?;
+            ),
-
+            RelativeEpoch::Current => EpochCrosslinkCommitteesBuilder::for_current_epoch(
-            for (slot_committees_index, (committee, shard)) in slot_committees.iter().enumerate() {
+                state,
-                // Empty committees are not permitted.
+                active_validator_indices.clone(),
-                if committee.is_empty() {
+                spec,
-                    return Err(Error::InsufficientValidators);
+            ),
+            RelativeEpoch::NextWithRegistryChange => {
+                EpochCrosslinkCommitteesBuilder::for_next_epoch(
+                    state,
+                    active_validator_indices.clone(),
+                    true,
+                    spec,
+                )?
             }
+            RelativeEpoch::NextWithoutRegistryChange => {
+                EpochCrosslinkCommitteesBuilder::for_next_epoch(
+                    state,
+                    active_validator_indices.clone(),
+                    false,
+                    spec,
+                )?
+            }
+        };
+        let epoch_crosslink_committees = builder.build(spec)?;
 
-                trace!(
+        // Loop through all the validators in the committees and create the following maps:
-                    "shard: {}, epoch_i: {}, slot_i: {}",
+        //
+        // 1. `attestation_duties`: maps `ValidatorIndex` to `AttestationDuty`.
+        // 2. `shard_committee_indices`: maps `Shard` into a `CrosslinkCommittee` in
+        //    `EpochCrosslinkCommittees`.
+        let mut attestation_duties = vec![None; state.validator_registry.len()];
+        let mut shard_committee_indices = vec![None; spec.shard_count as usize];
+        for (i, slot_committees) in epoch_crosslink_committees
+            .crosslink_committees
+            .iter()
+            .enumerate()
+        {
+            let slot = epoch.start_slot(spec.slots_per_epoch) + i as u64;
+
+            for (j, crosslink_committee) in slot_committees.iter().enumerate() {
+                let shard = crosslink_committee.shard;
+
+                shard_committee_indices[shard as usize] = Some((slot, j));
+
+                for (k, validator_index) in crosslink_committee.committee.iter().enumerate() {
+                    let attestation_duty = AttestationDuty {
+                        slot,
                         shard,
-                    epoch_committeess_index,
+                        committee_index: k,
-                    slot_committees_index
+                    };
-                );
+                    attestation_duties[*validator_index] = Some(attestation_duty)
-
-                shard_committee_index_map
-                    .insert(*shard, (epoch_committeess_index, slot_committees_index));
-
-                for (committee_index, validator_index) in committee.iter().enumerate() {
-                    attestation_duty_map.insert(
-                        *validator_index as u64,
-                        (slot, *shard, committee_index as u64),
-                    );
                 }
             }
-
-            epoch_committees.push(slot_committees)
         }
 
         Ok(EpochCache {
-            initialized: true,
+            initialized_epoch: Some(epoch),
-            committees: epoch_committees,
+            epoch_crosslink_committees,
-            attestation_duty_map,
+            attestation_duties,
-            shard_committee_index_map,
+            shard_committee_indices,
+            active_validator_indices,
         })
     }
+
+    /// Return a vec of `CrosslinkCommittee` for a given slot.
+    pub fn get_crosslink_committees_at_slot(
+        &self,
+        slot: Slot,
+        spec: &ChainSpec,
+    ) -> Option<&Vec<CrosslinkCommittee>> {
+        self.epoch_crosslink_committees
+            .get_crosslink_committees_at_slot(slot, spec)
+    }
+
+    /// Return `Some(CrosslinkCommittee)` if the given shard has a committee during the given
+    /// `epoch`.
+    pub fn get_crosslink_committee_for_shard(
+        &self,
+        shard: Shard,
+        spec: &ChainSpec,
+    ) -> Option<&CrosslinkCommittee> {
+        if shard > self.shard_committee_indices.len() as u64 {
+            None
+        } else {
+            let (slot, committee) = self.shard_committee_indices[shard as usize]?;
+            let slot_committees = self.get_crosslink_committees_at_slot(slot, spec)?;
+            slot_committees.get(committee)
+        }
+    }
+}
+
+/// Returns a list of all `validator_registry` indices where the validator is active at the given
+/// `epoch`.
+///
+/// Spec v0.5.0
+pub fn get_active_validator_indices(validators: &[Validator], epoch: Epoch) -> Vec<usize> {
+    let mut active = Vec::with_capacity(validators.len());
+
+    for (index, validator) in validators.iter().enumerate() {
+        if validator.is_active_at(epoch) {
+            active.push(index)
+        }
+    }
+
+    active.shrink_to_fit();
+
+    active
+}
+
+/// Contains all `CrosslinkCommittees` for an epoch.
+#[derive(Debug, Default, PartialEq, Clone, Serialize, Deserialize)]
+pub struct EpochCrosslinkCommittees {
+    /// The epoch the committees are present in.
+    epoch: Epoch,
+    /// Each commitee for each slot of the epoch.
+    pub crosslink_committees: Vec<Vec<CrosslinkCommittee>>,
+}
+
+impl EpochCrosslinkCommittees {
+    /// Return a new instances where all slots have zero committees.
+    fn new(epoch: Epoch, spec: &ChainSpec) -> Self {
+        Self {
+            epoch,
+            crosslink_committees: vec![vec![]; spec.slots_per_epoch as usize],
+        }
+    }
+
+    /// Return a vec of `CrosslinkCommittee` for a given slot.
+    fn get_crosslink_committees_at_slot(
+        &self,
+        slot: Slot,
+        spec: &ChainSpec,
+    ) -> Option<&Vec<CrosslinkCommittee>> {
+        let epoch_start_slot = self.epoch.start_slot(spec.slots_per_epoch);
+        let epoch_end_slot = self.epoch.end_slot(spec.slots_per_epoch);
+
+        if (epoch_start_slot <= slot) && (slot <= epoch_end_slot) {
+            let index = slot - epoch_start_slot;
+            self.crosslink_committees.get(index.as_usize())
+        } else {
+            None
+        }
+    }
+}
+
+/// Builds an `EpochCrosslinkCommittees` object.
+pub struct EpochCrosslinkCommitteesBuilder {
+    epoch: Epoch,
+    shuffling_start_shard: Shard,
+    shuffling_seed: Hash256,
+    active_validator_indices: Vec<usize>,
+    committees_per_epoch: u64,
+}
+
+impl EpochCrosslinkCommitteesBuilder {
+    /// Instantiates a builder that will build for the `state`'s previous epoch.
+    pub fn for_previous_epoch(
+        state: &BeaconState,
+        active_validator_indices: Vec<usize>,
+        spec: &ChainSpec,
+    ) -> Self {
+        Self {
+            epoch: state.previous_epoch(spec),
+            shuffling_start_shard: state.previous_shuffling_start_shard,
+            shuffling_seed: state.previous_shuffling_seed,
+            committees_per_epoch: spec.get_epoch_committee_count(active_validator_indices.len()),
+            active_validator_indices,
+        }
+    }
+
+    /// Instantiates a builder that will build for the `state`'s next epoch.
+    pub fn for_current_epoch(
+        state: &BeaconState,
+        active_validator_indices: Vec<usize>,
+        spec: &ChainSpec,
+    ) -> Self {
+        Self {
+            epoch: state.current_epoch(spec),
+            shuffling_start_shard: state.current_shuffling_start_shard,
+            shuffling_seed: state.current_shuffling_seed,
+            committees_per_epoch: spec.get_epoch_committee_count(active_validator_indices.len()),
+            active_validator_indices,
+        }
+    }
+
+    /// Instantiates a builder that will build for the `state`'s next epoch.
+    ///
+    /// Note: there are two possible epoch builds for the next epoch, one where there is a registry
+    /// change and one where there is not.
+    pub fn for_next_epoch(
+        state: &BeaconState,
+        active_validator_indices: Vec<usize>,
+        registry_change: bool,
+        spec: &ChainSpec,
+    ) -> Result<Self, Error> {
+        let current_epoch = state.current_epoch(spec);
+        let next_epoch = state.next_epoch(spec);
+        let committees_per_epoch = spec.get_epoch_committee_count(active_validator_indices.len());
+
+        let epochs_since_last_registry_update =
+            current_epoch - state.validator_registry_update_epoch;
+
+        let (seed, shuffling_start_shard) = if registry_change {
+            let next_seed = state
+                .generate_seed(next_epoch, spec)
+                .map_err(|_| Error::UnableToGenerateSeed)?;
+            (
+                next_seed,
+                (state.current_shuffling_start_shard + committees_per_epoch) % spec.shard_count,
+            )
+        } else if (epochs_since_last_registry_update > 1)
+            & epochs_since_last_registry_update.is_power_of_two()
+        {
+            let next_seed = state
+                .generate_seed(next_epoch, spec)
+                .map_err(|_| Error::UnableToGenerateSeed)?;
+            (next_seed, state.current_shuffling_start_shard)
+        } else {
+            (
+                state.current_shuffling_seed,
+                state.current_shuffling_start_shard,
+            )
+        };
+
+        Ok(Self {
+            epoch: state.next_epoch(spec),
+            shuffling_start_shard,
+            shuffling_seed: seed,
+            active_validator_indices,
+            committees_per_epoch,
+        })
+    }
+
+    /// Consumes the builder, returning a fully-build `EpochCrosslinkCommittee`.
+    pub fn build(self, spec: &ChainSpec) -> Result<EpochCrosslinkCommittees, Error> {
+        // The shuffler fails on a empty list, so if there are no active validator indices, simply
+        // return an empty list.
+        let shuffled_active_validator_indices = if self.active_validator_indices.is_empty() {
+            vec![]
+        } else {
+            shuffle_list(
+                self.active_validator_indices,
+                spec.shuffle_round_count,
+                &self.shuffling_seed[..],
+                true,
+            )
+            .ok_or_else(|| Error::UnableToShuffle)?
+        };
+
+        let mut committees: Vec<Vec<usize>> = shuffled_active_validator_indices
+            .honey_badger_split(self.committees_per_epoch as usize)
+            .map(|slice: &[usize]| slice.to_vec())
+            .collect();
+
+        let mut epoch_crosslink_committees = EpochCrosslinkCommittees::new(self.epoch, spec);
+        let mut shard = self.shuffling_start_shard;
+
+        let committees_per_slot = (self.committees_per_epoch / spec.slots_per_epoch) as usize;
+
+        for (i, slot) in self.epoch.slot_iter(spec.slots_per_epoch).enumerate() {
+            for j in (0..committees.len())
+                .skip(i * committees_per_slot)
+                .take(committees_per_slot)
+            {
+                let crosslink_committee = CrosslinkCommittee {
+                    slot,
+                    shard,
+                    committee: committees[j].drain(..).collect(),
+                };
+                epoch_crosslink_committees.crosslink_committees[i].push(crosslink_committee);
+
+                shard += 1;
+                shard %= spec.shard_count;
+            }
+        }
+
+        Ok(epoch_crosslink_committees)
+    }
 }

eth2/types/src/beacon_state/epoch_cache/tests.rs

@@ -0,0 +1,149 @@
+#![cfg(test)]
+
+use super::*;
+use crate::test_utils::*;
+use swap_or_not_shuffle::shuffle_list;
+
+fn do_sane_cache_test(
+    state: BeaconState,
+    epoch: Epoch,
+    relative_epoch: RelativeEpoch,
+    validator_count: usize,
+    expected_seed: Hash256,
+    expected_shuffling_start: u64,
+    spec: &ChainSpec,
+) {
+    let active_indices: Vec<usize> = (0..validator_count).collect();
+
+    assert_eq!(
+        &active_indices[..],
+        state
+            .get_cached_active_validator_indices(relative_epoch, &spec)
+            .unwrap(),
+        "Validator indices mismatch"
+    );
+
+    let shuffling = shuffle_list(
+        active_indices,
+        spec.shuffle_round_count,
+        &expected_seed[..],
+        true,
+    )
+    .unwrap();
+
+    let committees_per_epoch = spec.get_epoch_committee_count(shuffling.len());
+    let committees_per_slot = committees_per_epoch / spec.slots_per_epoch;
+
+    let mut expected_indices_iter = shuffling.iter();
+    let mut shard_counter = expected_shuffling_start;
+
+    for (i, slot) in epoch.slot_iter(spec.slots_per_epoch).enumerate() {
+        let crosslink_committees_at_slot =
+            state.get_crosslink_committees_at_slot(slot, &spec).unwrap();
+
+        assert_eq!(
+            crosslink_committees_at_slot.len(),
+            committees_per_slot as usize,
+            "Bad committees per slot ({})",
+            i
+        );
+
+        for c in crosslink_committees_at_slot {
+            assert_eq!(c.shard, shard_counter, "Bad shard");
+            shard_counter += 1;
+            shard_counter %= spec.shard_count;
+
+            for &i in &c.committee {
+                assert_eq!(
+                    i,
+                    *expected_indices_iter.next().unwrap(),
+                    "Non-sequential validators."
+                );
+            }
+        }
+    }
+}
+
+fn setup_sane_cache_test(validator_count: usize, spec: &ChainSpec) -> BeaconState {
+    let mut builder =
+        TestingBeaconStateBuilder::from_default_keypairs_file_if_exists(validator_count, spec);
+
+    let epoch = spec.genesis_epoch + 4;
+    let slot = epoch.start_slot(spec.slots_per_epoch);
+    builder.teleport_to_slot(slot, spec);
+
+    let (mut state, _keypairs) = builder.build();
+
+    state.current_shuffling_start_shard = 0;
+    state.current_shuffling_seed = Hash256::from_slice(&[1; 32]);
+
+    state.previous_shuffling_start_shard = spec.shard_count - 1;
+    state.previous_shuffling_seed = Hash256::from_slice(&[2; 32]);
+
+    state
+        .build_epoch_cache(RelativeEpoch::Previous, spec)
+        .unwrap();
+    state
+        .build_epoch_cache(RelativeEpoch::Current, spec)
+        .unwrap();
+    state
+        .build_epoch_cache(RelativeEpoch::NextWithRegistryChange, spec)
+        .unwrap();
+    state
+        .build_epoch_cache(RelativeEpoch::NextWithoutRegistryChange, spec)
+        .unwrap();
+
+    state
+}
+
+#[test]
+fn builds_sane_current_epoch_cache() {
+    let mut spec = ChainSpec::few_validators();
+    spec.shard_count = 4;
+    let validator_count = (spec.shard_count * spec.target_committee_size) + 1;
+    let state = setup_sane_cache_test(validator_count as usize, &spec);
+    do_sane_cache_test(
+        state.clone(),
+        state.current_epoch(&spec),
+        RelativeEpoch::Current,
+        validator_count as usize,
+        state.current_shuffling_seed,
+        state.current_shuffling_start_shard,
+        &spec,
+    );
+}
+
+#[test]
+fn builds_sane_previous_epoch_cache() {
+    let mut spec = ChainSpec::few_validators();
+    spec.shard_count = 2;
+    let validator_count = (spec.shard_count * spec.target_committee_size) + 1;
+    let state = setup_sane_cache_test(validator_count as usize, &spec);
+    do_sane_cache_test(
+        state.clone(),
+        state.previous_epoch(&spec),
+        RelativeEpoch::Previous,
+        validator_count as usize,
+        state.previous_shuffling_seed,
+        state.previous_shuffling_start_shard,
+        &spec,
+    );
+}
+
+#[test]
+fn builds_sane_next_without_update_epoch_cache() {
+    let mut spec = ChainSpec::few_validators();
+    spec.shard_count = 2;
+    let validator_count = (spec.shard_count * spec.target_committee_size) + 1;
+    let mut state = setup_sane_cache_test(validator_count as usize, &spec);
+    state.validator_registry_update_epoch = state.slot.epoch(spec.slots_per_epoch);
+    do_sane_cache_test(
+        state.clone(),
+        state.next_epoch(&spec),
+        RelativeEpoch::NextWithoutRegistryChange,
+        validator_count as usize,
+        state.current_shuffling_seed,
+        state.current_shuffling_start_shard,
+        &spec,
+    );
+}

eth2/types/src/beacon_state/pubkey_cache.rs

@@ -1,25 +1,22 @@
 use crate::*;
-use serde_derive::Serialize;
+use serde_derive::{Deserialize, Serialize};
 use std::collections::HashMap;
 
 type ValidatorIndex = usize;
 
-#[derive(Debug, PartialEq, Clone, Default, Serialize)]
+#[derive(Debug, PartialEq, Clone, Default, Serialize, Deserialize)]
 pub struct PubkeyCache {
+    /// Maintain the number of keys added to the map. It is not sufficient to just use the HashMap
+    /// len, as it does not increase when duplicate keys are added. Duplicate keys are used during
+    /// testing.
+    len: usize,
     map: HashMap<PublicKey, ValidatorIndex>,
 }
 
 impl PubkeyCache {
-    /// Instantiates a new, empty cache.
+    /// Returns the number of validator indices added to the map so far.
-    pub fn empty() -> Self {
-        Self {
-            map: HashMap::new(),
-        }
-    }
-
-    /// Returns the number of validator indices already in the map.
     pub fn len(&self) -> ValidatorIndex {
-        self.map.len()
+        self.len
     }
 
     /// Inserts a validator index into the map.
@@ -27,8 +24,9 @@ impl PubkeyCache {
     /// The added index must equal the number of validators already added to the map. This ensures
     /// that an index is never skipped.
     pub fn insert(&mut self, pubkey: PublicKey, index: ValidatorIndex) -> bool {
-        if index == self.map.len() {
+        if index == self.len {
             self.map.insert(pubkey, index);
+            self.len += 1;
             true
         } else {
             false

eth2/types/src/beacon_state/tests.rs

@@ -1,53 +1,57 @@
 #![cfg(test)]
-
 use super::*;
-use crate::test_utils::TestingBeaconStateBuilder;
+use crate::test_utils::*;
-use crate::test_utils::{SeedableRng, TestRandom, XorShiftRng};
-use crate::{BeaconState, ChainSpec};
-
-/// Tests that `get_attestation_participants` is consistent with the result of
-/// get_crosslink_committees_at_slot` with a full bitfield.
-#[test]
-pub fn get_attestation_participants_consistency() {
-    let mut rng = XorShiftRng::from_seed([42; 16]);
-
-    let spec = ChainSpec::few_validators();
-    let builder = TestingBeaconStateBuilder::from_deterministic_keypairs(8, &spec);
-    let (mut state, _keypairs) = builder.build();
-
-    state
-        .build_epoch_cache(RelativeEpoch::Previous, &spec)
-        .unwrap();
-    state
-        .build_epoch_cache(RelativeEpoch::Current, &spec)
-        .unwrap();
-    state.build_epoch_cache(RelativeEpoch::Next, &spec).unwrap();
-
-    for slot in state
-        .slot
-        .epoch(spec.slots_per_epoch)
-        .slot_iter(spec.slots_per_epoch)
-    {
-        let committees = state.get_crosslink_committees_at_slot(slot, &spec).unwrap();
-
-        for (committee, shard) in committees {
-            let mut attestation_data = AttestationData::random_for_test(&mut rng);
-            attestation_data.slot = slot;
-            attestation_data.shard = *shard;
-
-            let mut bitfield = Bitfield::new();
-            for (i, _) in committee.iter().enumerate() {
-                bitfield.set(i, true);
-            }
-
-            assert_eq!(
-                state
-                    .get_attestation_participants(&attestation_data, &bitfield, &spec)
-                    .unwrap(),
-                *committee
-            );
-        }
-    }
-}
 
 ssz_tests!(BeaconState);
+
+/// Test that
+///
+/// 1. Using the cache before it's built fails.
+/// 2. Using the cache after it's build passes.
+/// 3. Using the cache after it's dropped fails.
+fn test_cache_initialization<'a>(
+    state: &'a mut BeaconState,
+    relative_epoch: RelativeEpoch,
+    spec: &ChainSpec,
+) {
+    let slot = relative_epoch
+        .into_epoch(state.slot.epoch(spec.slots_per_epoch))
+        .start_slot(spec.slots_per_epoch);
+
+    // Assuming the cache isn't already built, assert that a call to a cache-using function fails.
+    assert_eq!(
+        state.get_beacon_proposer_index(slot, relative_epoch, spec),
+        Err(BeaconStateError::EpochCacheUninitialized(relative_epoch))
+    );
+
+    // Build the cache.
+    state.build_epoch_cache(relative_epoch, spec).unwrap();
+
+    // Assert a call to a cache-using function passes.
+    let _ = state
+        .get_beacon_proposer_index(slot, relative_epoch, spec)
+        .unwrap();
+
+    // Drop the cache.
+    state.drop_cache(relative_epoch);
+
+    // Assert a call to a cache-using function fail.
+    assert_eq!(
+        state.get_beacon_proposer_index(slot, relative_epoch, spec),
+        Err(BeaconStateError::EpochCacheUninitialized(relative_epoch))
+    );
+}
+
+#[test]
+fn cache_initialization() {
+    let spec = ChainSpec::few_validators();
+    let (mut state, _keypairs) =
+        TestingBeaconStateBuilder::from_default_keypairs_file_if_exists(16, &spec).build();
+
+    state.slot = (spec.genesis_epoch + 1).start_slot(spec.slots_per_epoch);
+
+    test_cache_initialization(&mut state, RelativeEpoch::Previous, &spec);
+    test_cache_initialization(&mut state, RelativeEpoch::Current, &spec);
+    test_cache_initialization(&mut state, RelativeEpoch::NextWithRegistryChange, &spec);
+    test_cache_initialization(&mut state, RelativeEpoch::NextWithoutRegistryChange, &spec);
+}

eth2/types/src/chain_spec.rs

@@ -1,21 +1,27 @@
-use crate::{Address, Epoch, Fork, Hash256, Slot};
+use crate::*;
 use bls::Signature;
+use int_to_bytes::int_to_bytes4;
+use serde_derive::Deserialize;
 
 const GWEI: u64 = 1_000_000_000;
 
+/// Each of the BLS signature domains.
+///
+/// Spec v0.5.0
 pub enum Domain {
-    Deposit,
+    BeaconBlock,
-    Attestation,
-    Proposal,
-    Exit,
     Randao,
+    Attestation,
+    Deposit,
+    Exit,
     Transfer,
 }
 
 /// Holds all the "constants" for a BeaconChain.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
-#[derive(PartialEq, Debug, Clone)]
+#[derive(PartialEq, Debug, Clone, Deserialize)]
+#[serde(default)]
 pub struct ChainSpec {
     /*
      * Misc
@@ -23,8 +29,7 @@ pub struct ChainSpec {
     pub shard_count: u64,
     pub target_committee_size: u64,
     pub max_balance_churn_quotient: u64,
-    pub beacon_chain_shard_number: u64,
+    pub max_indices_per_slashable_vote: usize,
-    pub max_indices_per_slashable_vote: u64,
     pub max_exit_dequeues_per_epoch: u64,
     pub shuffle_round_count: u8,
 
@@ -45,7 +50,7 @@ pub struct ChainSpec {
     /*
      * Initial Values
      */
-    pub genesis_fork_version: u64,
+    pub genesis_fork_version: u32,
     pub genesis_slot: Slot,
     pub genesis_epoch: Epoch,
     pub genesis_start_shard: u64,
@@ -63,12 +68,13 @@ pub struct ChainSpec {
     pub min_seed_lookahead: Epoch,
     pub activation_exit_delay: u64,
     pub epochs_per_eth1_voting_period: u64,
+    pub slots_per_historical_root: usize,
     pub min_validator_withdrawability_delay: Epoch,
+    pub persistent_committee_period: u64,
 
     /*
      * State list lengths
      */
-    pub latest_block_roots_length: usize,
     pub latest_randao_mixes_length: usize,
     pub latest_active_index_roots_length: usize,
     pub latest_slashed_exit_length: usize,
@@ -100,18 +106,18 @@ pub struct ChainSpec {
      *
      * Use `ChainSpec::get_domain(..)` to access these values.
      */
-    domain_deposit: u64,
+    domain_beacon_block: u32,
-    domain_attestation: u64,
+    domain_randao: u32,
-    domain_proposal: u64,
+    domain_attestation: u32,
-    domain_exit: u64,
+    domain_deposit: u32,
-    domain_randao: u64,
+    domain_exit: u32,
-    domain_transfer: u64,
+    domain_transfer: u32,
 }
 
 impl ChainSpec {
     /// Return the number of committees in one epoch.
     ///
-    /// Spec v0.4.0
+    /// Spec v0.5.0
     pub fn get_epoch_committee_count(&self, active_validator_count: usize) -> u64 {
         std::cmp::max(
             1,
@@ -124,24 +130,29 @@ impl ChainSpec {
 
     /// Get the domain number that represents the fork meta and signature domain.
     ///
-    /// Spec v0.4.0
+    /// Spec v0.5.0
     pub fn get_domain(&self, epoch: Epoch, domain: Domain, fork: &Fork) -> u64 {
         let domain_constant = match domain {
-            Domain::Deposit => self.domain_deposit,
+            Domain::BeaconBlock => self.domain_beacon_block,
-            Domain::Attestation => self.domain_attestation,
-            Domain::Proposal => self.domain_proposal,
-            Domain::Exit => self.domain_exit,
             Domain::Randao => self.domain_randao,
+            Domain::Attestation => self.domain_attestation,
+            Domain::Deposit => self.domain_deposit,
+            Domain::Exit => self.domain_exit,
             Domain::Transfer => self.domain_transfer,
         };
 
-        let fork_version = fork.get_fork_version(epoch);
+        let mut bytes: Vec<u8> = fork.get_fork_version(epoch).to_vec();
-        fork_version * u64::pow(2, 32) + domain_constant
+        bytes.append(&mut int_to_bytes4(domain_constant));
+
+        let mut fork_and_domain = [0; 8];
+        fork_and_domain.copy_from_slice(&bytes);
+
+        u64::from_le_bytes(fork_and_domain)
     }
 
     /// Returns a `ChainSpec` compatible with the Ethereum Foundation specification.
     ///
-    /// Spec v0.4.0
+    /// Spec v0.5.0
     pub fn foundation() -> Self {
         let genesis_slot = Slot::new(2_u64.pow(32));
         let slots_per_epoch = 64;
@@ -154,7 +165,6 @@ impl ChainSpec {
             shard_count: 1_024,
             target_committee_size: 128,
             max_balance_churn_quotient: 32,
-            beacon_chain_shard_number: u64::max_value(),
             max_indices_per_slashable_vote: 4_096,
             max_exit_dequeues_per_epoch: 4,
             shuffle_round_count: 90,
@@ -194,12 +204,13 @@ impl ChainSpec {
             min_seed_lookahead: Epoch::new(1),
             activation_exit_delay: 4,
             epochs_per_eth1_voting_period: 16,
+            slots_per_historical_root: 8_192,
             min_validator_withdrawability_delay: Epoch::new(256),
+            persistent_committee_period: 2_048,
 
             /*
              * State list lengths
              */
-            latest_block_roots_length: 8_192,
             latest_randao_mixes_length: 8_192,
             latest_active_index_roots_length: 8_192,
             latest_slashed_exit_length: 8_192,
@@ -226,18 +237,16 @@ impl ChainSpec {
             /*
              * Signature domains
              */
-            domain_deposit: 0,
+            domain_beacon_block: 0,
-            domain_attestation: 1,
+            domain_randao: 1,
-            domain_proposal: 2,
+            domain_attestation: 2,
-            domain_exit: 3,
+            domain_deposit: 3,
-            domain_randao: 4,
+            domain_exit: 4,
             domain_transfer: 5,
         }
     }
 
     /// Returns a `ChainSpec` compatible with the specification suitable for 8 validators.
-    ///
-    /// Spec v0.4.0
     pub fn few_validators() -> Self {
         let genesis_slot = Slot::new(2_u64.pow(32));
         let slots_per_epoch = 8;
@@ -254,12 +263,43 @@ impl ChainSpec {
     }
 }
 
+impl Default for ChainSpec {
+    fn default() -> Self {
+        Self::foundation()
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
+    use int_to_bytes::int_to_bytes8;
 
     #[test]
     fn test_foundation_spec_can_be_constructed() {
         let _ = ChainSpec::foundation();
     }
+
+    fn test_domain(domain_type: Domain, raw_domain: u32, spec: &ChainSpec) {
+        let fork = Fork::genesis(&spec);
+        let epoch = Epoch::new(0);
+
+        let domain = spec.get_domain(epoch, domain_type, &fork);
+
+        let mut expected = fork.get_fork_version(epoch).to_vec();
+        expected.append(&mut int_to_bytes4(raw_domain));
+
+        assert_eq!(int_to_bytes8(domain), expected);
+    }
+
+    #[test]
+    fn test_get_domain() {
+        let spec = ChainSpec::foundation();
+
+        test_domain(Domain::BeaconBlock, spec.domain_beacon_block, &spec);
+        test_domain(Domain::Randao, spec.domain_randao, &spec);
+        test_domain(Domain::Attestation, spec.domain_attestation, &spec);
+        test_domain(Domain::Deposit, spec.domain_deposit, &spec);
+        test_domain(Domain::Exit, spec.domain_exit, &spec);
+        test_domain(Domain::Transfer, spec.domain_transfer, &spec);
+    }
 }

eth2/types/src/crosslink.rs

@@ -1,15 +1,25 @@
 use crate::test_utils::TestRandom;
 use crate::{Epoch, Hash256};
 use rand::RngCore;
-use serde_derive::Serialize;
+use serde_derive::{Deserialize, Serialize};
 use ssz_derive::{Decode, Encode, TreeHash};
 use test_random_derive::TestRandom;
 
 /// Specifies the block hash for a shard at an epoch.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 #[derive(
-    Debug, Clone, PartialEq, Default, Serialize, Hash, Encode, Decode, TreeHash, TestRandom,
+    Debug,
+    Clone,
+    PartialEq,
+    Default,
+    Serialize,
+    Deserialize,
+    Hash,
+    Encode,
+    Decode,
+    TreeHash,
+    TestRandom,
 )]
 pub struct Crosslink {
     pub epoch: Epoch,

eth2/types/src/crosslink_committee.rs

@@ -0,0 +1,10 @@
+use crate::*;
+use serde_derive::{Deserialize, Serialize};
+use ssz_derive::{Decode, Encode, TreeHash};
+
+#[derive(Default, Clone, Debug, PartialEq, Serialize, Deserialize, Decode, Encode, TreeHash)]
+pub struct CrosslinkCommittee {
+    pub slot: Slot,
+    pub shard: Shard,
+    pub committee: Vec<usize>,
+}

eth2/types/src/deposit.rs

@@ -7,10 +7,10 @@ use test_random_derive::TestRandom;
 
 /// A deposit to potentially become a beacon chain validator.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 #[derive(Debug, PartialEq, Clone, Serialize, Deserialize, Encode, Decode, TreeHash, TestRandom)]
 pub struct Deposit {
-    pub branch: Vec<Hash256>,
+    pub proof: Vec<Hash256>,
     pub index: u64,
     pub deposit_data: DepositData,
 }

eth2/types/src/deposit_data.rs

@@ -7,7 +7,7 @@ use test_random_derive::TestRandom;
 
 /// Data generated by the deposit contract.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 #[derive(Debug, PartialEq, Clone, Serialize, Deserialize, Encode, Decode, TreeHash, TestRandom)]
 pub struct DepositData {
     pub amount: u64,

eth2/types/src/deposit_input.rs

@@ -1,6 +1,6 @@
 use crate::test_utils::TestRandom;
 use crate::*;
-use bls::{Keypair, PublicKey, Signature};
+use bls::{PublicKey, Signature};
 use rand::RngCore;
 use serde_derive::{Deserialize, Serialize};
 use ssz::{SignedRoot, TreeHash};
@@ -9,7 +9,7 @@ use test_random_derive::TestRandom;
 
 /// The data supplied by the user to the deposit contract.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
 #[derive(
     Debug,
     PartialEq,
@@ -31,25 +31,23 @@ pub struct DepositInput {
 impl DepositInput {
     /// Generate the 'proof_of_posession' signature for a given DepositInput details.
     ///
-    /// Spec v0.4.0
+    /// Spec v0.5.0
     pub fn create_proof_of_possession(
-        keypair: &Keypair,
+        &self,
-        withdrawal_credentials: &Hash256,
+        secret_key: &SecretKey,
-        domain: u64,
+        epoch: Epoch,
+        fork: &Fork,
+        spec: &ChainSpec,
     ) -> Signature {
-        let signable_deposit_input = DepositInput {
+        let msg = self.signed_root();
-            pubkey: keypair.pk.clone(),
+        let domain = spec.get_domain(epoch, Domain::Deposit, fork);
-            withdrawal_credentials: withdrawal_credentials.clone(),
-            proof_of_possession: Signature::empty_signature(),
-        };
-        let msg = signable_deposit_input.signed_root();
 
-        Signature::new(msg.as_slice(), domain, &keypair.sk)
+        Signature::new(msg.as_slice(), domain, secret_key)
     }
 
     /// Verify that proof-of-possession is valid.
     ///
-    /// Spec v0.4.0
+    /// Spec v0.5.0
     pub fn validate_proof_of_possession(
         &self,
         epoch: Epoch,
@@ -68,4 +66,23 @@ mod tests {
     use super::*;
 
     ssz_tests!(DepositInput);
+
+    #[test]
+    fn can_create_and_validate() {
+        let spec = ChainSpec::foundation();
+        let fork = Fork::genesis(&spec);
+        let keypair = Keypair::random();
+        let epoch = Epoch::new(0);
+
+        let mut deposit_input = DepositInput {
+            pubkey: keypair.pk.clone(),
+            withdrawal_credentials: Hash256::zero(),
+            proof_of_possession: Signature::empty_signature(),
+        };
+
+        deposit_input.proof_of_possession =
+            deposit_input.create_proof_of_possession(&keypair.sk, epoch, &fork, &spec);
+
+        assert!(deposit_input.validate_proof_of_possession(epoch, &fork, &spec));
+    }
 }

eth2/types/src/eth1_data.rs

@@ -1,14 +1,16 @@
 use super::Hash256;
 use crate::test_utils::TestRandom;
 use rand::RngCore;
-use serde_derive::Serialize;
+use serde_derive::{Deserialize, Serialize};
 use ssz_derive::{Decode, Encode, TreeHash};
 use test_random_derive::TestRandom;
 
 /// Contains data obtained from the Eth1 chain.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
-#[derive(Debug, PartialEq, Clone, Default, Serialize, Encode, Decode, TreeHash, TestRandom)]
+#[derive(
+    Debug, PartialEq, Clone, Default, Serialize, Deserialize, Encode, Decode, TreeHash, TestRandom,
+)]
 pub struct Eth1Data {
     pub deposit_root: Hash256,
     pub block_hash: Hash256,

eth2/types/src/eth1_data_vote.rs

@@ -1,14 +1,16 @@
 use super::Eth1Data;
 use crate::test_utils::TestRandom;
 use rand::RngCore;
-use serde_derive::Serialize;
+use serde_derive::{Deserialize, Serialize};
 use ssz_derive::{Decode, Encode, TreeHash};
 use test_random_derive::TestRandom;
 
 /// A summation of votes for some `Eth1Data`.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
-#[derive(Debug, PartialEq, Clone, Default, Serialize, Encode, Decode, TreeHash, TestRandom)]
+#[derive(
+    Debug, PartialEq, Clone, Default, Serialize, Deserialize, Encode, Decode, TreeHash, TestRandom,
+)]
 pub struct Eth1DataVote {
     pub eth1_data: Eth1Data,
     pub vote_count: u64,

eth2/types/src/fork.rs

@@ -1,24 +1,41 @@
-use crate::{test_utils::TestRandom, Epoch};
+use crate::{test_utils::TestRandom, ChainSpec, Epoch};
+use int_to_bytes::int_to_bytes4;
 use rand::RngCore;
-use serde_derive::Serialize;
+use serde_derive::{Deserialize, Serialize};
 use ssz_derive::{Decode, Encode, TreeHash};
 use test_random_derive::TestRandom;
 
 /// Specifies a fork of the `BeaconChain`, to prevent replay attacks.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
-#[derive(Debug, Clone, PartialEq, Default, Serialize, Encode, Decode, TreeHash, TestRandom)]
+#[derive(
+    Debug, Clone, PartialEq, Default, Serialize, Deserialize, Encode, Decode, TreeHash, TestRandom,
+)]
 pub struct Fork {
-    pub previous_version: u64,
+    pub previous_version: [u8; 4],
-    pub current_version: u64,
+    pub current_version: [u8; 4],
     pub epoch: Epoch,
 }
 
 impl Fork {
+    /// Initialize the `Fork` from the genesis parameters in the `spec`.
+    ///
+    /// Spec v0.5.0
+    pub fn genesis(spec: &ChainSpec) -> Self {
+        let mut current_version: [u8; 4] = [0; 4];
+        current_version.copy_from_slice(&int_to_bytes4(spec.genesis_fork_version));
+
+        Self {
+            previous_version: current_version,
+            current_version,
+            epoch: spec.genesis_epoch,
+        }
+    }
+
     /// Return the fork version of the given ``epoch``.
     ///
-    /// Spec v0.4.0
+    /// Spec v0.5.0
-    pub fn get_fork_version(&self, epoch: Epoch) -> u64 {
+    pub fn get_fork_version(&self, epoch: Epoch) -> [u8; 4] {
         if epoch < self.epoch {
             return self.previous_version;
         }
@@ -31,4 +48,49 @@ mod tests {
     use super::*;
 
     ssz_tests!(Fork);
+
+    fn test_genesis(version: u32, epoch: Epoch) {
+        let mut spec = ChainSpec::foundation();
+
+        spec.genesis_fork_version = version;
+        spec.genesis_epoch = epoch;
+
+        let fork = Fork::genesis(&spec);
+
+        assert_eq!(fork.epoch, spec.genesis_epoch, "epoch incorrect");
+        assert_eq!(
+            fork.previous_version, fork.current_version,
+            "previous and current are not identical"
+        );
+        assert_eq!(
+            fork.current_version,
+            version.to_le_bytes(),
+            "current version incorrect"
+        );
+    }
+
+    #[test]
+    fn genesis() {
+        test_genesis(0, Epoch::new(0));
+        test_genesis(9, Epoch::new(11));
+        test_genesis(2_u32.pow(31), Epoch::new(2_u64.pow(63)));
+        test_genesis(u32::max_value(), Epoch::max_value());
+    }
+
+    #[test]
+    fn get_fork_version() {
+        let previous_version = [1; 4];
+        let current_version = [2; 4];
+        let epoch = Epoch::new(10);
+
+        let fork = Fork {
+            previous_version,
+            current_version,
+            epoch,
+        };
+
+        assert_eq!(fork.get_fork_version(epoch - 1), previous_version);
+        assert_eq!(fork.get_fork_version(epoch), current_version);
+        assert_eq!(fork.get_fork_version(epoch + 1), current_version);
+    }
 }

eth2/types/src/historical_batch.rs

@@ -0,0 +1,22 @@
+use crate::test_utils::TestRandom;
+use crate::Hash256;
+use rand::RngCore;
+use serde_derive::{Deserialize, Serialize};
+use ssz_derive::{Decode, Encode, TreeHash};
+use test_random_derive::TestRandom;
+
+/// Historical block and state roots.
+///
+/// Spec v0.5.0
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, Encode, Decode, TreeHash, TestRandom)]
+pub struct HistoricalBatch {
+    pub block_roots: Vec<Hash256>,
+    pub state_roots: Vec<Hash256>,
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    ssz_tests!(HistoricalBatch);
+}

eth2/types/src/lib.rs

@@ -6,12 +6,15 @@ pub mod test_utils;
 pub mod attestation;
 pub mod attestation_data;
 pub mod attestation_data_and_custody_bit;
+pub mod attestation_duty;
 pub mod attester_slashing;
 pub mod beacon_block;
 pub mod beacon_block_body;
+pub mod beacon_block_header;
 pub mod beacon_state;
 pub mod chain_spec;
 pub mod crosslink;
+pub mod crosslink_committee;
 pub mod deposit;
 pub mod deposit_data;
 pub mod deposit_input;
@@ -19,20 +22,18 @@ pub mod eth1_data;
 pub mod eth1_data_vote;
 pub mod fork;
 pub mod free_attestation;
+pub mod historical_batch;
 pub mod pending_attestation;
-pub mod proposal;
 pub mod proposer_slashing;
-pub mod readers;
-pub mod shard_reassignment_record;
 pub mod slashable_attestation;
 pub mod transfer;
 pub mod voluntary_exit;
 #[macro_use]
 pub mod slot_epoch_macros;
+pub mod relative_epoch;
 pub mod slot_epoch;
 pub mod slot_height;
 pub mod validator;
-pub mod validator_registry;
 
 use ethereum_types::{H160, H256, U256};
 use std::collections::HashMap;
@@ -40,12 +41,15 @@ use std::collections::HashMap;
 pub use crate::attestation::Attestation;
 pub use crate::attestation_data::AttestationData;
 pub use crate::attestation_data_and_custody_bit::AttestationDataAndCustodyBit;
+pub use crate::attestation_duty::AttestationDuty;
 pub use crate::attester_slashing::AttesterSlashing;
 pub use crate::beacon_block::BeaconBlock;
 pub use crate::beacon_block_body::BeaconBlockBody;
-pub use crate::beacon_state::{BeaconState, Error as BeaconStateError, RelativeEpoch};
+pub use crate::beacon_block_header::BeaconBlockHeader;
+pub use crate::beacon_state::{BeaconState, Error as BeaconStateError};
 pub use crate::chain_spec::{ChainSpec, Domain};
 pub use crate::crosslink::Crosslink;
+pub use crate::crosslink_committee::CrosslinkCommittee;
 pub use crate::deposit::Deposit;
 pub use crate::deposit_data::DepositData;
 pub use crate::deposit_input::DepositInput;
@@ -53,9 +57,10 @@ pub use crate::eth1_data::Eth1Data;
 pub use crate::eth1_data_vote::Eth1DataVote;
 pub use crate::fork::Fork;
 pub use crate::free_attestation::FreeAttestation;
+pub use crate::historical_batch::HistoricalBatch;
 pub use crate::pending_attestation::PendingAttestation;
-pub use crate::proposal::Proposal;
 pub use crate::proposer_slashing::ProposerSlashing;
+pub use crate::relative_epoch::{Error as RelativeEpochError, RelativeEpoch};
 pub use crate::slashable_attestation::SlashableAttestation;
 pub use crate::slot_epoch::{Epoch, Slot};
 pub use crate::slot_height::SlotHeight;
@@ -63,6 +68,10 @@ pub use crate::transfer::Transfer;
 pub use crate::validator::Validator;
 pub use crate::voluntary_exit::VoluntaryExit;
 
+pub type Shard = u64;
+pub type Committee = Vec<usize>;
+pub type CrosslinkCommittees = Vec<(Committee, u64)>;
+
 pub type Hash256 = H256;
 pub type Address = H160;
 pub type EthBalance = U256;

eth2/types/src/pending_attestation.rs

@@ -1,14 +1,14 @@
 use crate::test_utils::TestRandom;
 use crate::{AttestationData, Bitfield, Slot};
 use rand::RngCore;
-use serde_derive::Serialize;
+use serde_derive::{Deserialize, Serialize};
 use ssz_derive::{Decode, Encode, TreeHash};
 use test_random_derive::TestRandom;
 
 /// An attestation that has been included in the state but not yet fully processed.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
-#[derive(Debug, Clone, PartialEq, Serialize, Encode, Decode, TreeHash, TestRandom)]
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, Encode, Decode, TreeHash, TestRandom)]
 pub struct PendingAttestation {
     pub aggregation_bitfield: Bitfield,
     pub data: AttestationData,

eth2/types/src/proposal.rs

@@ -1,56 +0,0 @@
-use crate::test_utils::TestRandom;
-use crate::{Hash256, Slot};
-use bls::Signature;
-use rand::RngCore;
-use serde_derive::Serialize;
-use ssz::TreeHash;
-use ssz_derive::{Decode, Encode, SignedRoot, TreeHash};
-use test_random_derive::TestRandom;
-
-/// A proposal for some shard or beacon block.
-///
-/// Spec v0.4.0
-#[derive(Debug, PartialEq, Clone, Serialize, Encode, Decode, TreeHash, TestRandom, SignedRoot)]
-pub struct Proposal {
-    pub slot: Slot,
-    /// Shard number (spec.beacon_chain_shard_number for beacon chain)
-    pub shard: u64,
-    pub block_root: Hash256,
-    pub signature: Signature,
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use crate::test_utils::{SeedableRng, TestRandom, XorShiftRng};
-    use ssz::{SignedRoot, TreeHash};
-
-    #[derive(TreeHash)]
-    struct SignedProposal {
-        pub slot: Slot,
-        pub shard: u64,
-        pub block_root: Hash256,
-    }
-
-    impl Into<SignedProposal> for Proposal {
-        fn into(self) -> SignedProposal {
-            SignedProposal {
-                slot: self.slot,
-                shard: self.shard,
-                block_root: self.block_root,
-            }
-        }
-    }
-
-    #[test]
-    pub fn test_signed_root() {
-        let mut rng = XorShiftRng::from_seed([42; 16]);
-        let original = Proposal::random_for_test(&mut rng);
-
-        let other: SignedProposal = original.clone().into();
-
-        assert_eq!(original.signed_root(), other.hash_tree_root());
-    }
-
-    ssz_tests!(Proposal);
-}

eth2/types/src/proposal_signed_data.rs

@@ -1,20 +0,0 @@
-use crate::test_utils::TestRandom;
-use crate::{Hash256, Slot};
-use rand::RngCore;
-use serde_derive::Serialize;
-use ssz_derive::{Decode, Encode, TreeHash};
-use test_random_derive::TestRandom;
-
-#[derive(Debug, PartialEq, Clone, Default, Serialize, Encode, Decode, TreeHash, TestRandom)]
-pub struct ProposalSignedData {
-    pub slot: Slot,
-    pub shard: u64,
-    pub block_root: Hash256,
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    ssz_tests!(ProposalSignedData);
-}

eth2/types/src/proposer_slashing.rs

@@ -1,18 +1,18 @@
-use super::Proposal;
+use super::BeaconBlockHeader;
 use crate::test_utils::TestRandom;
 use rand::RngCore;
-use serde_derive::Serialize;
+use serde_derive::{Deserialize, Serialize};
 use ssz_derive::{Decode, Encode, TreeHash};
 use test_random_derive::TestRandom;
 
 /// Two conflicting proposals from the same proposer (validator).
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
-#[derive(Debug, PartialEq, Clone, Serialize, Encode, Decode, TreeHash, TestRandom)]
+#[derive(Debug, PartialEq, Clone, Serialize, Deserialize, Encode, Decode, TreeHash, TestRandom)]
 pub struct ProposerSlashing {
     pub proposer_index: u64,
-    pub proposal_1: Proposal,
+    pub header_1: BeaconBlockHeader,
-    pub proposal_2: Proposal,
+    pub header_2: BeaconBlockHeader,
 }
 
 #[cfg(test)]

eth2/types/src/readers/block_reader.rs

@@ -1,35 +0,0 @@
-use crate::{BeaconBlock, Hash256, Slot};
-use std::fmt::Debug;
-
-/// The `BeaconBlockReader` provides interfaces for reading a subset of fields of a `BeaconBlock`.
-///
-/// The purpose of this trait is to allow reading from either;
-///  - a standard `BeaconBlock` struct, or
-///  - a SSZ serialized byte array.
-///
-/// Note: presently, direct SSZ reading has not been implemented so this trait is being used for
-/// "future proofing".
-pub trait BeaconBlockReader: Debug + PartialEq {
-    fn slot(&self) -> Slot;
-    fn parent_root(&self) -> Hash256;
-    fn state_root(&self) -> Hash256;
-    fn into_beacon_block(self) -> Option<BeaconBlock>;
-}
-
-impl BeaconBlockReader for BeaconBlock {
-    fn slot(&self) -> Slot {
-        self.slot
-    }
-
-    fn parent_root(&self) -> Hash256 {
-        self.parent_root
-    }
-
-    fn state_root(&self) -> Hash256 {
-        self.state_root
-    }
-
-    fn into_beacon_block(self) -> Option<BeaconBlock> {
-        Some(self)
-    }
-}

eth2/types/src/readers/mod.rs

@@ -1,5 +0,0 @@
-mod block_reader;
-mod state_reader;
-
-pub use self::block_reader::BeaconBlockReader;
-pub use self::state_reader::BeaconStateReader;

eth2/types/src/readers/state_reader.rs

@@ -1,25 +0,0 @@
-use crate::{BeaconState, Slot};
-use std::fmt::Debug;
-
-/// The `BeaconStateReader` provides interfaces for reading a subset of fields of a `BeaconState`.
-///
-/// The purpose of this trait is to allow reading from either;
-///  - a standard `BeaconState` struct, or
-///  - a SSZ serialized byte array.
-///
-/// Note: presently, direct SSZ reading has not been implemented so this trait is being used for
-/// "future proofing".
-pub trait BeaconStateReader: Debug + PartialEq {
-    fn slot(&self) -> Slot;
-    fn into_beacon_state(self) -> Option<BeaconState>;
-}
-
-impl BeaconStateReader for BeaconState {
-    fn slot(&self) -> Slot {
-        self.slot
-    }
-
-    fn into_beacon_state(self) -> Option<BeaconState> {
-        Some(self)
-    }
-}

eth2/types/src/relative_epoch.rs

@@ -0,0 +1,134 @@
+use crate::*;
+
+#[derive(Debug, PartialEq, Clone, Copy)]
+pub enum Error {
+    EpochTooLow { base: Epoch, other: Epoch },
+    EpochTooHigh { base: Epoch, other: Epoch },
+    AmbiguiousNextEpoch,
+}
+
+/// Defines the epochs relative to some epoch. Most useful when referring to the committees prior
+/// to and following some epoch.
+///
+/// Spec v0.5.0
+#[derive(Debug, PartialEq, Clone, Copy)]
+pub enum RelativeEpoch {
+    /// The prior epoch.
+    Previous,
+    /// The current epoch.
+    Current,
+    /// The next epoch if there _is_ a validator registry update.
+    ///
+    /// If the validator registry is updated during an epoch transition, a new shuffling seed is
+    /// generated, this changes the attestation and proposal roles.
+    NextWithRegistryChange,
+    /// The next epoch if there _is not_ a validator registry update.
+    ///
+    /// If the validator registry _is not_ updated during an epoch transition, the shuffling stays
+    /// the same.
+    NextWithoutRegistryChange,
+}
+
+impl RelativeEpoch {
+    /// Returns the `epoch` that `self` refers to, with respect to the `base` epoch.
+    ///
+    /// Spec v0.5.0
+    pub fn into_epoch(self, base: Epoch) -> Epoch {
+        match self {
+            RelativeEpoch::Previous => base - 1,
+            RelativeEpoch::Current => base,
+            RelativeEpoch::NextWithoutRegistryChange => base + 1,
+            RelativeEpoch::NextWithRegistryChange => base + 1,
+        }
+    }
+
+    /// Converts the `other` epoch into a `RelativeEpoch`, with respect to `base`
+    ///
+    /// ## Errors
+    /// Returns an error when:
+    /// - `EpochTooLow` when `other` is more than 1 prior to `base`.
+    /// - `EpochTooHigh` when `other` is more than 1 after `base`.
+    /// - `AmbiguiousNextEpoch` whenever `other` is one after `base`, because it's unknowable if
+    ///   there will be a registry change.
+    ///
+    /// Spec v0.5.0
+    pub fn from_epoch(base: Epoch, other: Epoch) -> Result<Self, Error> {
+        if other == base - 1 {
+            Ok(RelativeEpoch::Previous)
+        } else if other == base {
+            Ok(RelativeEpoch::Current)
+        } else if other == base + 1 {
+            Err(Error::AmbiguiousNextEpoch)
+        } else if other < base {
+            Err(Error::EpochTooLow { base, other })
+        } else {
+            Err(Error::EpochTooHigh { base, other })
+        }
+    }
+
+    /// Convenience function for `Self::from_epoch` where both slots are converted into epochs.
+    pub fn from_slot(base: Slot, other: Slot, spec: &ChainSpec) -> Result<Self, Error> {
+        Self::from_epoch(
+            base.epoch(spec.slots_per_epoch),
+            other.epoch(spec.slots_per_epoch),
+        )
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_into_epoch() {
+        let base = Epoch::new(10);
+
+        assert_eq!(RelativeEpoch::Current.into_epoch(base), base);
+        assert_eq!(RelativeEpoch::Previous.into_epoch(base), base - 1);
+        assert_eq!(
+            RelativeEpoch::NextWithRegistryChange.into_epoch(base),
+            base + 1
+        );
+        assert_eq!(
+            RelativeEpoch::NextWithoutRegistryChange.into_epoch(base),
+            base + 1
+        );
+    }
+
+    #[test]
+    fn from_epoch() {
+        let base = Epoch::new(10);
+
+        assert_eq!(
+            RelativeEpoch::from_epoch(base, base - 1),
+            Ok(RelativeEpoch::Previous)
+        );
+        assert_eq!(
+            RelativeEpoch::from_epoch(base, base),
+            Ok(RelativeEpoch::Current)
+        );
+        assert_eq!(
+            RelativeEpoch::from_epoch(base, base + 1),
+            Err(RelativeEpochError::AmbiguiousNextEpoch)
+        );
+    }
+
+    #[test]
+    fn from_slot() {
+        let spec = ChainSpec::foundation();
+        let base = Epoch::new(10).start_slot(spec.slots_per_epoch);
+
+        assert_eq!(
+            RelativeEpoch::from_slot(base, base - 1, &spec),
+            Ok(RelativeEpoch::Previous)
+        );
+        assert_eq!(
+            RelativeEpoch::from_slot(base, base, &spec),
+            Ok(RelativeEpoch::Current)
+        );
+        assert_eq!(
+            RelativeEpoch::from_slot(base, base + spec.slots_per_epoch, &spec),
+            Err(RelativeEpochError::AmbiguiousNextEpoch)
+        );
+    }
+}

eth2/types/src/shard_reassignment_record.rs

@@ -1,19 +0,0 @@
-use crate::{test_utils::TestRandom, Slot};
-use rand::RngCore;
-use serde_derive::Serialize;
-use ssz_derive::{Decode, Encode, TreeHash};
-use test_random_derive::TestRandom;
-
-#[derive(Debug, PartialEq, Clone, Serialize, Encode, Decode, TreeHash, TestRandom)]
-pub struct ShardReassignmentRecord {
-    pub validator_index: u64,
-    pub shard: u64,
-    pub slot: Slot,
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    ssz_tests!(ShardReassignmentRecord);
-}

eth2/types/src/slashable_attestation.rs

@@ -1,6 +1,6 @@
 use crate::{test_utils::TestRandom, AggregateSignature, AttestationData, Bitfield, ChainSpec};
 use rand::RngCore;
-use serde_derive::Serialize;
+use serde_derive::{Deserialize, Serialize};
 use ssz::TreeHash;
 use ssz_derive::{Decode, Encode, SignedRoot, TreeHash};
 use test_random_derive::TestRandom;
@@ -9,8 +9,19 @@ use test_random_derive::TestRandom;
 ///
 /// To be included in an `AttesterSlashing`.
 ///
-/// Spec v0.4.0
+/// Spec v0.5.0
-#[derive(Debug, PartialEq, Clone, Serialize, Encode, Decode, TreeHash, TestRandom, SignedRoot)]
+#[derive(
+    Debug,
+    PartialEq,
+    Clone,
+    Serialize,
+    Deserialize,
+    Encode,
+    Decode,
+    TreeHash,
+    TestRandom,
+    SignedRoot,
+)]
 pub struct SlashableAttestation {
     /// Lists validator registry indices, not committee indices.
     pub validator_indices: Vec<u64>,
@@ -22,17 +33,17 @@ pub struct SlashableAttestation {
 impl SlashableAttestation {
     /// Check if ``attestation_data_1`` and ``attestation_data_2`` have the same target.
     ///
-    /// Spec v0.4.0
+    /// Spec v0.5.0
     pub fn is_double_vote(&self, other: &SlashableAttestation, spec: &ChainSpec) -> bool {
         self.data.slot.epoch(spec.slots_per_epoch) == other.data.slot.epoch(spec.slots_per_epoch)
     }
 
     /// Check if ``attestation_data_1`` surrounds ``attestation_data_2``.
     ///
-    /// Spec v0.4.0
+    /// Spec v0.5.0
     pub fn is_surround_vote(&self, other: &SlashableAttestation, spec: &ChainSpec) -> bool {
-        let source_epoch_1 = self.data.justified_epoch;
+        let source_epoch_1 = self.data.source_epoch;
-        let source_epoch_2 = other.data.justified_epoch;
+        let source_epoch_2 = other.data.source_epoch;
         let target_epoch_1 = self.data.slot.epoch(spec.slots_per_epoch);
         let target_epoch_2 = other.data.slot.epoch(spec.slots_per_epoch);
 
@@ -123,14 +134,14 @@ mod tests {
 
     fn create_slashable_attestation(
         slot_factor: u64,
-        justified_epoch: u64,
+        source_epoch: u64,
         spec: &ChainSpec,
     ) -> SlashableAttestation {
         let mut rng = XorShiftRng::from_seed([42; 16]);
         let mut slashable_vote = SlashableAttestation::random_for_test(&mut rng);
 
         slashable_vote.data.slot = Slot::new(slot_factor * spec.slots_per_epoch);
-        slashable_vote.data.justified_epoch = Epoch::new(justified_epoch);
+        slashable_vote.data.source_epoch = Epoch::new(source_epoch);
         slashable_vote
     }
 }

eth2/types/src/slashable_vote_data.rs

@@ -1,132 +0,0 @@
-use super::AttestationData;
-use crate::chain_spec::ChainSpec;
-use crate::test_utils::TestRandom;
-use bls::AggregateSignature;
-use rand::RngCore;
-use serde_derive::Serialize;
-use ssz_derive::{Decode, Encode, TreeHash};
-use test_random_derive::TestRandom;
-
-#[derive(Debug, PartialEq, Clone, Serialize, Encode, Decode, TreeHash, TestRandom)]
-pub struct SlashableVoteData {
-    pub custody_bit_0_indices: Vec<u32>,
-    pub custody_bit_1_indices: Vec<u32>,
-    pub data: AttestationData,
-    pub aggregate_signature: AggregateSignature,
-}
-
-impl SlashableVoteData {
-    /// Check if ``attestation_data_1`` and ``attestation_data_2`` have the same target.
-    ///
-    /// Spec v0.3.0
-    pub fn is_double_vote(&self, other: &SlashableVoteData, spec: &ChainSpec) -> bool {
-        self.data.slot.epoch(spec.epoch_length) == other.data.slot.epoch(spec.epoch_length)
-    }
-
-    /// Check if ``attestation_data_1`` surrounds ``attestation_data_2``.
-    ///
-    /// Spec v0.3.0
-    pub fn is_surround_vote(&self, other: &SlashableVoteData, spec: &ChainSpec) -> bool {
-        let source_epoch_1 = self.data.justified_epoch;
-        let source_epoch_2 = other.data.justified_epoch;
-        let target_epoch_1 = self.data.slot.epoch(spec.epoch_length);
-        let target_epoch_2 = other.data.slot.epoch(spec.epoch_length);
-
-        (source_epoch_1 < source_epoch_2) && (target_epoch_2 < target_epoch_1)
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use crate::chain_spec::ChainSpec;
-    use crate::slot_epoch::{Epoch, Slot};
-    use crate::test_utils::{SeedableRng, TestRandom, XorShiftRng};
-
-    #[test]
-    pub fn test_is_double_vote_true() {
-        let spec = ChainSpec::foundation();
-        let slashable_vote_first = create_slashable_vote_data(1, 1, &spec);
-        let slashable_vote_second = create_slashable_vote_data(1, 1, &spec);
-
-        assert_eq!(
-            slashable_vote_first.is_double_vote(&slashable_vote_second, &spec),
-            true
-        )
-    }
-
-    #[test]
-    pub fn test_is_double_vote_false() {
-        let spec = ChainSpec::foundation();
-        let slashable_vote_first = create_slashable_vote_data(1, 1, &spec);
-        let slashable_vote_second = create_slashable_vote_data(2, 1, &spec);
-
-        assert_eq!(
-            slashable_vote_first.is_double_vote(&slashable_vote_second, &spec),
-            false
-        );
-    }
-
-    #[test]
-    pub fn test_is_surround_vote_true() {
-        let spec = ChainSpec::foundation();
-        let slashable_vote_first = create_slashable_vote_data(2, 1, &spec);
-        let slashable_vote_second = create_slashable_vote_data(1, 2, &spec);
-
-        assert_eq!(
-            slashable_vote_first.is_surround_vote(&slashable_vote_second, &spec),
-            true
-        );
-    }
-
-    #[test]
-    pub fn test_is_surround_vote_true_realistic() {
-        let spec = ChainSpec::foundation();
-        let slashable_vote_first = create_slashable_vote_data(4, 1, &spec);
-        let slashable_vote_second = create_slashable_vote_data(3, 2, &spec);
-
-        assert_eq!(
-            slashable_vote_first.is_surround_vote(&slashable_vote_second, &spec),
-            true
-        );
-    }
-
-    #[test]
-    pub fn test_is_surround_vote_false_source_epoch_fails() {
-        let spec = ChainSpec::foundation();
-        let slashable_vote_first = create_slashable_vote_data(2, 2, &spec);
-        let slashable_vote_second = create_slashable_vote_data(1, 1, &spec);
-
-        assert_eq!(
-            slashable_vote_first.is_surround_vote(&slashable_vote_second, &spec),
-            false
-        );
-    }
-
-    #[test]
-    pub fn test_is_surround_vote_false_target_epoch_fails() {
-        let spec = ChainSpec::foundation();
-        let slashable_vote_first = create_slashable_vote_data(1, 1, &spec);
-        let slashable_vote_second = create_slashable_vote_data(2, 2, &spec);
-
-        assert_eq!(
-            slashable_vote_first.is_surround_vote(&slashable_vote_second, &spec),
-            false
-        );
-    }
-
-    ssz_tests!(SlashableVoteData);
-
-    fn create_slashable_vote_data(
-        slot_factor: u64,
-        justified_epoch: u64,
-        spec: &ChainSpec,
-    ) -> SlashableVoteData {
-        let mut rng = XorShiftRng::from_seed([42; 16]);
-        let mut slashable_vote = SlashableVoteData::random_for_test(&mut rng);
-
-        slashable_vote.data.slot = Slot::new(slot_factor * spec.epoch_length);
-        slashable_vote.data.justified_epoch = Epoch::new(justified_epoch);
-        slashable_vote
-    }
-}

eth2/types/src/test_utils/mod.rs

@@ -4,10 +4,12 @@ mod generate_deterministic_keypairs;
 mod keypairs_file;
 mod test_random;
 mod testing_attestation_builder;
+mod testing_attestation_data_builder;
 mod testing_attester_slashing_builder;
 mod testing_beacon_block_builder;
 mod testing_beacon_state_builder;
 mod testing_deposit_builder;
+mod testing_pending_attestation_builder;
 mod testing_proposer_slashing_builder;
 mod testing_transfer_builder;
 mod testing_voluntary_exit_builder;
@@ -17,10 +19,12 @@ pub use keypairs_file::KeypairsFile;
 pub use rand::{prng::XorShiftRng, SeedableRng};
 pub use test_random::TestRandom;
 pub use testing_attestation_builder::TestingAttestationBuilder;
+pub use testing_attestation_data_builder::TestingAttestationDataBuilder;
 pub use testing_attester_slashing_builder::TestingAttesterSlashingBuilder;
 pub use testing_beacon_block_builder::TestingBeaconBlockBuilder;
 pub use testing_beacon_state_builder::{keypairs_path, TestingBeaconStateBuilder};
 pub use testing_deposit_builder::TestingDepositBuilder;
+pub use testing_pending_attestation_builder::TestingPendingAttestationBuilder;
 pub use testing_proposer_slashing_builder::TestingProposerSlashingBuilder;
 pub use testing_transfer_builder::TestingTransferBuilder;
 pub use testing_voluntary_exit_builder::TestingVoluntaryExitBuilder;

eth2/types/src/test_utils/test_random.rs

@@ -51,3 +51,17 @@ where
         ]
     }
 }
+
+macro_rules! impl_test_random_for_u8_array {
+    ($len: expr) => {
+        impl<T: RngCore> TestRandom<T> for [u8; $len] {
+            fn random_for_test(rng: &mut T) -> Self {
+                let mut bytes = [0; $len];
+                rng.fill_bytes(&mut bytes);
+                bytes
+            }
+        }
+    };
+}
+
+impl_test_random_for_u8_array!(4);

eth2/types/src/test_utils/testing_attestation_builder.rs

@@ -1,3 +1,4 @@
+use crate::test_utils::TestingAttestationDataBuilder;
 use crate::*;
 use ssz::TreeHash;
 
@@ -18,31 +19,7 @@ impl TestingAttestationBuilder {
         shard: u64,
         spec: &ChainSpec,
     ) -> Self {
-        let current_epoch = state.current_epoch(spec);
+        let data_builder = TestingAttestationDataBuilder::new(state, shard, slot, spec);
-        let previous_epoch = state.previous_epoch(spec);
-
-        let is_previous_epoch =
-            state.slot.epoch(spec.slots_per_epoch) != slot.epoch(spec.slots_per_epoch);
-
-        let justified_epoch = if is_previous_epoch {
-            state.previous_justified_epoch
-        } else {
-            state.justified_epoch
-        };
-
-        let epoch_boundary_root = if is_previous_epoch {
-            *state
-                .get_block_root(previous_epoch.start_slot(spec.slots_per_epoch), spec)
-                .unwrap()
-        } else {
-            *state
-                .get_block_root(current_epoch.start_slot(spec.slots_per_epoch), spec)
-                .unwrap()
-        };
-
-        let justified_block_root = *state
-            .get_block_root(justified_epoch.start_slot(spec.slots_per_epoch), spec)
-            .unwrap();
 
         let mut aggregation_bitfield = Bitfield::new();
         let mut custody_bitfield = Bitfield::new();
@@ -54,16 +31,7 @@ impl TestingAttestationBuilder {
 
         let attestation = Attestation {
             aggregation_bitfield,
-            data: AttestationData {
+            data: data_builder.build(),
-                slot,
-                shard,
-                beacon_block_root: *state.get_block_root(slot, spec).unwrap(),
-                epoch_boundary_root,
-                crosslink_data_root: Hash256::zero(),
-                latest_crosslink: state.latest_crosslinks[shard as usize].clone(),
-                justified_epoch,
-                justified_block_root,
-            },
             custody_bitfield,
             aggregate_signature: AggregateSignature::new(),
         };

eth2/types/src/test_utils/testing_attestation_data_builder.rs

@@ -0,0 +1,66 @@
+use crate::*;
+
+/// Builds an `AttestationData` to be used for testing purposes.
+///
+/// This struct should **never be used for production purposes.**
+pub struct TestingAttestationDataBuilder {
+    data: AttestationData,
+}
+
+impl TestingAttestationDataBuilder {
+    /// Configures a new `AttestationData` which attests to all of the same parameters as the
+    /// state.
+    pub fn new(state: &BeaconState, shard: u64, slot: Slot, spec: &ChainSpec) -> Self {
+        let current_epoch = state.current_epoch(spec);
+        let previous_epoch = state.previous_epoch(spec);
+
+        let is_previous_epoch =
+            state.slot.epoch(spec.slots_per_epoch) != slot.epoch(spec.slots_per_epoch);
+
+        let source_epoch = if is_previous_epoch {
+            state.previous_justified_epoch
+        } else {
+            state.current_justified_epoch
+        };
+
+        let target_root = if is_previous_epoch {
+            *state
+                .get_block_root(previous_epoch.start_slot(spec.slots_per_epoch), spec)
+                .unwrap()
+        } else {
+            *state
+                .get_block_root(current_epoch.start_slot(spec.slots_per_epoch), spec)
+                .unwrap()
+        };
+
+        let source_root = *state
+            .get_block_root(source_epoch.start_slot(spec.slots_per_epoch), spec)
+            .unwrap();
+
+        let data = AttestationData {
+            // LMD GHOST vote
+            slot,
+            beacon_block_root: *state.get_block_root(slot, spec).unwrap(),
+
+            // FFG Vote
+            source_epoch,
+            source_root,
+            target_root,
+
+            // Crosslink vote
+            shard,
+            previous_crosslink: Crosslink {
+                epoch: slot.epoch(spec.slots_per_epoch),
+                crosslink_data_root: spec.zero_hash,
+            },
+            crosslink_data_root: spec.zero_hash,
+        };
+
+        Self { data }
+    }
+
+    /// Returns the `AttestationData`, consuming the builder.
+    pub fn build(self) -> AttestationData {
+        self.data
+    }
+}

eth2/types/src/test_utils/testing_attester_slashing_builder.rs

@@ -23,45 +23,39 @@ impl TestingAttesterSlashingBuilder {
     {
         let double_voted_slot = Slot::new(0);
         let shard = 0;
-        let justified_epoch = Epoch::new(0);
         let epoch = Epoch::new(0);
         let hash_1 = Hash256::from_low_u64_le(1);
         let hash_2 = Hash256::from_low_u64_le(2);
 
-        let mut slashable_attestation_1 = SlashableAttestation {
+        let data_1 = AttestationData {
-            validator_indices: validator_indices.to_vec(),
-            data: AttestationData {
             slot: double_voted_slot,
-                shard,
             beacon_block_root: hash_1,
-                epoch_boundary_root: hash_1,
+            source_epoch: epoch,
-                crosslink_data_root: hash_1,
+            source_root: hash_1,
-                latest_crosslink: Crosslink {
+            target_root: hash_1,
+            shard,
+            previous_crosslink: Crosslink {
                 epoch,
                 crosslink_data_root: hash_1,
             },
-                justified_epoch,
+            crosslink_data_root: hash_1,
-                justified_block_root: hash_1,
+        };
-            },
+
+        let data_2 = AttestationData {
+            beacon_block_root: hash_2,
+            ..data_1.clone()
+        };
+
+        let mut slashable_attestation_1 = SlashableAttestation {
+            validator_indices: validator_indices.to_vec(),
+            data: data_1,
             custody_bitfield: Bitfield::new(),
             aggregate_signature: AggregateSignature::new(),
         };
 
         let mut slashable_attestation_2 = SlashableAttestation {
             validator_indices: validator_indices.to_vec(),
-            data: AttestationData {
+            data: data_2,
-                slot: double_voted_slot,
-                shard,
-                beacon_block_root: hash_2,
-                epoch_boundary_root: hash_2,
-                crosslink_data_root: hash_2,
-                latest_crosslink: Crosslink {
-                    epoch,
-                    crosslink_data_root: hash_2,
-                },
-                justified_epoch,
-                justified_block_root: hash_2,
-            },
             custody_bitfield: Bitfield::new(),
             aggregate_signature: AggregateSignature::new(),
         };

eth2/types/src/test_utils/testing_beacon_block_builder.rs

@@ -12,14 +12,14 @@ use ssz::{SignedRoot, TreeHash};
 ///
 /// This struct should **never be used for production purposes.**
 pub struct TestingBeaconBlockBuilder {
-    block: BeaconBlock,
+    pub block: BeaconBlock,
 }
 
 impl TestingBeaconBlockBuilder {
     /// Create a new builder from genesis.
     pub fn new(spec: &ChainSpec) -> Self {
         Self {
-            block: BeaconBlock::genesis(spec.zero_hash, spec),
+            block: BeaconBlock::empty(spec),
         }
     }
 
@@ -32,10 +32,9 @@ impl TestingBeaconBlockBuilder {
     ///
     /// Modifying the block after signing may invalidate the signature.
     pub fn sign(&mut self, sk: &SecretKey, fork: &Fork, spec: &ChainSpec) {
-        let proposal = self.block.proposal(spec);
+        let message = self.block.signed_root();
-        let message = proposal.signed_root();
         let epoch = self.block.slot.epoch(spec.slots_per_epoch);
-        let domain = spec.get_domain(epoch, Domain::Proposal, fork);
+        let domain = spec.get_domain(epoch, Domain::BeaconBlock, fork);
         self.block.signature = Signature::new(&message, domain, sk);
     }
 
@@ -46,7 +45,7 @@ impl TestingBeaconBlockBuilder {
         let epoch = self.block.slot.epoch(spec.slots_per_epoch);
         let message = epoch.hash_tree_root();
         let domain = spec.get_domain(epoch, Domain::Randao, fork);
-        self.block.randao_reveal = Signature::new(&message, domain, sk);
+        self.block.body.randao_reveal = Signature::new(&message, domain, sk);
     }
 
     /// Inserts a signed, valid `ProposerSlashing` for the validator.
@@ -74,19 +73,20 @@ impl TestingBeaconBlockBuilder {
         self.block.body.attester_slashings.push(attester_slashing);
     }
 
-    /// Fills the block with `MAX_ATTESTATIONS` attestations.
+    /// Fills the block with `num_attestations` attestations.
     ///
     /// It will first go and get each committee that is able to include an attestation in this
-    /// block. If there are enough committees, it will produce an attestation for each. If there
+    /// block. If there _are_ enough committees, it will produce an attestation for each. If there
-    /// are _not_ enough committees, it will start splitting the committees in half until it
+    /// _are not_ enough committees, it will start splitting the committees in half until it
     /// achieves the target. It will then produce separate attestations for each split committee.
     ///
     /// Note: the signed messages of the split committees will be identical -- it would be possible
     /// to aggregate these split attestations.
-    pub fn fill_with_attestations(
+    pub fn insert_attestations(
         &mut self,
         state: &BeaconState,
         secret_keys: &[&SecretKey],
+        num_attestations: usize,
         spec: &ChainSpec,
     ) -> Result<(), BeaconStateError> {
         let mut slot = self.block.slot - spec.min_attestation_inclusion_delay;
@@ -109,12 +109,17 @@ impl TestingBeaconBlockBuilder {
                 break;
             }
 
-            for (committee, shard) in state.get_crosslink_committees_at_slot(slot, spec)? {
+            for crosslink_committee in state.get_crosslink_committees_at_slot(slot, spec)? {
-                if attestations_added >= spec.max_attestations {
+                if attestations_added >= num_attestations {
                     break;
                 }
 
-                committees.push((slot, committee.clone(), committee.clone(), *shard));
+                committees.push((
+                    slot,
+                    crosslink_committee.committee.clone(),
+                    crosslink_committee.committee.clone(),
+                    crosslink_committee.shard,
+                ));
 
                 attestations_added += 1;
             }
@@ -125,12 +130,12 @@ impl TestingBeaconBlockBuilder {
         // Loop through all the committees, splitting each one in half until we have
         // `MAX_ATTESTATIONS` committees.
         loop {
-            if committees.len() >= spec.max_attestations as usize {
+            if committees.len() >= num_attestations as usize {
                 break;
             }
 
             for index in 0..committees.len() {
-                if committees.len() >= spec.max_attestations as usize {
+                if committees.len() >= num_attestations as usize {
                     break;
                 }
 
@@ -175,9 +180,14 @@ impl TestingBeaconBlockBuilder {
     ) {
         let keypair = Keypair::random();
 
-        let mut builder = TestingDepositBuilder::new(amount);
+        let mut builder = TestingDepositBuilder::new(keypair.pk.clone(), amount);
         builder.set_index(index);
-        builder.sign(&keypair, state, spec);
+        builder.sign(
+            &keypair,
+            state.slot.epoch(spec.slots_per_epoch),
+            &state.fork,
+            spec,
+        );
 
         self.block.body.deposits.push(builder.build())
     }

eth2/types/src/test_utils/testing_beacon_state_builder.rs

@@ -1,5 +1,5 @@
 use super::{generate_deterministic_keypairs, KeypairsFile};
-use crate::beacon_state::BeaconStateBuilder;
+use crate::test_utils::TestingPendingAttestationBuilder;
 use crate::*;
 use bls::get_withdrawal_credentials;
 use dirs;
@@ -109,7 +109,8 @@ impl TestingBeaconStateBuilder {
                 Validator {
                     pubkey: keypair.pk.clone(),
                     withdrawal_credentials,
-                    activation_epoch: spec.far_future_epoch,
+                    // All validators start active.
+                    activation_epoch: spec.genesis_epoch,
                     exit_epoch: spec.far_future_epoch,
                     withdrawable_epoch: spec.far_future_epoch,
                     initiated_exit: false,
@@ -118,7 +119,7 @@ impl TestingBeaconStateBuilder {
             })
             .collect();
 
-        let mut state_builder = BeaconStateBuilder::new(
+        let mut state = BeaconState::genesis(
             0,
             Eth1Data {
                 deposit_root: Hash256::zero(),
@@ -130,16 +131,10 @@ impl TestingBeaconStateBuilder {
         let balances = vec![32_000_000_000; validator_count];
 
         debug!("Importing {} existing validators...", validator_count);
-        state_builder.import_existing_validators(
+        state.validator_registry = validators;
-            validators,
+        state.validator_balances = balances;
-            balances,
-            validator_count as u64,
-            spec,
-        );
 
-        let state = state_builder.build(spec).unwrap();
+        debug!("BeaconState initialized.");
-
-        debug!("BeaconState built.");
 
         Self { state, keypairs }
     }
@@ -158,7 +153,8 @@ impl TestingBeaconStateBuilder {
 
         state.build_epoch_cache(RelativeEpoch::Previous, &spec)?;
         state.build_epoch_cache(RelativeEpoch::Current, &spec)?;
-        state.build_epoch_cache(RelativeEpoch::Next, &spec)?;
+        state.build_epoch_cache(RelativeEpoch::NextWithRegistryChange, &spec)?;
+        state.build_epoch_cache(RelativeEpoch::NextWithoutRegistryChange, &spec)?;
 
         state.update_pubkey_cache()?;
 
@@ -189,7 +185,7 @@ impl TestingBeaconStateBuilder {
         state.current_shuffling_seed = Hash256::from_low_u64_le(1);
 
         state.previous_justified_epoch = epoch - 3;
-        state.justified_epoch = epoch - 2;
+        state.current_justified_epoch = epoch - 2;
         state.justification_bitfield = u64::max_value();
 
         state.finalized_epoch = epoch - 3;
@@ -218,7 +214,7 @@ impl TestingBeaconStateBuilder {
             - spec.min_attestation_inclusion_delay;
         let last_slot = std::cmp::min(state.slot.as_u64(), last_slot);
 
-        for slot in first_slot..last_slot + 1 {
+        for slot in first_slot..=last_slot {
             let slot = Slot::from(slot);
 
             let committees = state
@@ -226,77 +222,24 @@ impl TestingBeaconStateBuilder {
                 .unwrap()
                 .clone();
 
-            for (committee, shard) in committees {
+            for crosslink_committee in committees {
-                state
+                let mut builder = TestingPendingAttestationBuilder::new(
-                    .latest_attestations
+                    state,
-                    .push(committee_to_pending_attestation(
+                    crosslink_committee.shard,
-                        state, &committee, shard, slot, spec,
-                    ))
-            }
-        }
-    }
-}
-
-/// Maps a committee to a `PendingAttestation`.
-///
-/// The committee will be signed by all validators in the committee.
-fn committee_to_pending_attestation(
-    state: &BeaconState,
-    committee: &[usize],
-    shard: u64,
-    slot: Slot,
-    spec: &ChainSpec,
-) -> PendingAttestation {
-    let current_epoch = state.current_epoch(spec);
-    let previous_epoch = state.previous_epoch(spec);
-
-    let mut aggregation_bitfield = Bitfield::new();
-    let mut custody_bitfield = Bitfield::new();
-
-    for (i, _) in committee.iter().enumerate() {
-        aggregation_bitfield.set(i, true);
-        custody_bitfield.set(i, true);
-    }
-
-    let is_previous_epoch =
-        state.slot.epoch(spec.slots_per_epoch) != slot.epoch(spec.slots_per_epoch);
-
-    let justified_epoch = if is_previous_epoch {
-        state.previous_justified_epoch
-    } else {
-        state.justified_epoch
-    };
-
-    let epoch_boundary_root = if is_previous_epoch {
-        *state
-            .get_block_root(previous_epoch.start_slot(spec.slots_per_epoch), spec)
-            .unwrap()
-    } else {
-        *state
-            .get_block_root(current_epoch.start_slot(spec.slots_per_epoch), spec)
-            .unwrap()
-    };
-
-    let justified_block_root = *state
-        .get_block_root(justified_epoch.start_slot(spec.slots_per_epoch), spec)
-        .unwrap();
-
-    PendingAttestation {
-        aggregation_bitfield,
-        data: AttestationData {
                     slot,
-            shard,
+                    spec,
-            beacon_block_root: *state.get_block_root(slot, spec).unwrap(),
+                );
-            epoch_boundary_root,
+                // The entire committee should have signed the pending attestation.
-            crosslink_data_root: Hash256::zero(),
+                let signers = vec![true; crosslink_committee.committee.len()];
-            latest_crosslink: Crosslink {
+                builder.add_committee_participation(signers);
-                epoch: slot.epoch(spec.slots_per_epoch),
+                let attestation = builder.build();
-                crosslink_data_root: Hash256::zero(),
+
-            },
+                if attestation.data.slot.epoch(spec.slots_per_epoch) < state.current_epoch(spec) {
-            justified_epoch,
+                    state.previous_epoch_attestations.push(attestation)
-            justified_block_root,
+                } else {
-        },
+                    state.current_epoch_attestations.push(attestation)
-        custody_bitfield,
+                }
-        inclusion_slot: slot + spec.min_attestation_inclusion_delay,
+            }
+        }
     }
 }

eth2/types/src/test_utils/testing_deposit_builder.rs

@@ -10,17 +10,15 @@ pub struct TestingDepositBuilder {
 
 impl TestingDepositBuilder {
     /// Instantiates a new builder.
-    pub fn new(amount: u64) -> Self {
+    pub fn new(pubkey: PublicKey, amount: u64) -> Self {
-        let keypair = Keypair::random();
-
         let deposit = Deposit {
-            branch: vec![],
+            proof: vec![],
             index: 0,
             deposit_data: DepositData {
                 amount,
                 timestamp: 1,
                 deposit_input: DepositInput {
-                    pubkey: keypair.pk,
+                    pubkey,
                     withdrawal_credentials: Hash256::zero(),
                     proof_of_possession: Signature::empty_signature(),
                 },
@@ -40,21 +38,22 @@ impl TestingDepositBuilder {
     /// - `pubkey` to the signing pubkey.
     /// - `withdrawal_credentials` to the signing pubkey.
     /// - `proof_of_possesssion`
-    pub fn sign(&mut self, keypair: &Keypair, state: &BeaconState, spec: &ChainSpec) {
+    pub fn sign(&mut self, keypair: &Keypair, epoch: Epoch, fork: &Fork, spec: &ChainSpec) {
         let withdrawal_credentials = Hash256::from_slice(
             &get_withdrawal_credentials(&keypair.pk, spec.bls_withdrawal_prefix_byte)[..],
         );
 
-        let epoch = state.current_epoch(spec);
-        let domain = spec.get_domain(epoch, Domain::Deposit, &state.fork);
-
         self.deposit.deposit_data.deposit_input.pubkey = keypair.pk.clone();
         self.deposit
             .deposit_data
             .deposit_input
-            .withdrawal_credentials = withdrawal_credentials.clone();
+            .withdrawal_credentials = withdrawal_credentials;
-        self.deposit.deposit_data.deposit_input.proof_of_possession =
+
-            DepositInput::create_proof_of_possession(&keypair, &withdrawal_credentials, domain);
+        self.deposit.deposit_data.deposit_input.proof_of_possession = self
+            .deposit
+            .deposit_data
+            .deposit_input
+            .create_proof_of_possession(&keypair.sk, epoch, fork, spec);
     }
 
     /// Builds the deposit, consuming the builder.

eth2/types/src/test_utils/testing_pending_attestation_builder.rs

@@ -0,0 +1,55 @@
+use crate::test_utils::TestingAttestationDataBuilder;
+use crate::*;
+
+/// Builds an `AttesterSlashing` to be used for testing purposes.
+///
+/// This struct should **never be used for production purposes.**
+pub struct TestingPendingAttestationBuilder {
+    pending_attestation: PendingAttestation,
+}
+
+impl TestingPendingAttestationBuilder {
+    /// Create a new valid* `PendingAttestation` for the given parameters.
+    ///
+    /// The `inclusion_slot` will be set to be the earliest possible slot the `Attestation` could
+    /// have been included (`slot + MIN_ATTESTATION_INCLUSION_DELAY`).
+    ///
+    /// * The aggregation and custody bitfields will all be empty, they need to be set with
+    /// `Self::add_committee_participation`.
+    pub fn new(state: &BeaconState, shard: u64, slot: Slot, spec: &ChainSpec) -> Self {
+        let data_builder = TestingAttestationDataBuilder::new(state, shard, slot, spec);
+
+        let pending_attestation = PendingAttestation {
+            aggregation_bitfield: Bitfield::new(),
+            data: data_builder.build(),
+            custody_bitfield: Bitfield::new(),
+            inclusion_slot: slot + spec.min_attestation_inclusion_delay,
+        };
+
+        Self {
+            pending_attestation,
+        }
+    }
+
+    /// Sets the committee participation in the `PendingAttestation`.
+    ///
+    /// The `PendingAttestation` will appear to be signed by each committee member who's value in
+    /// `signers` is true.
+    pub fn add_committee_participation(&mut self, signers: Vec<bool>) {
+        let mut aggregation_bitfield = Bitfield::new();
+        let mut custody_bitfield = Bitfield::new();
+
+        for (i, signed) in signers.iter().enumerate() {
+            aggregation_bitfield.set(i, *signed);
+            custody_bitfield.set(i, false); // Fixed to `false` for phase 0.
+        }
+
+        self.pending_attestation.aggregation_bitfield = aggregation_bitfield;
+        self.pending_attestation.custody_bitfield = custody_bitfield;
+    }
+
+    /// Returns the `PendingAttestation`, consuming the builder.
+    pub fn build(self) -> PendingAttestation {
+        self.pending_attestation
+    }
+}

eth2/types/src/test_utils/testing_proposer_slashing_builder.rs

@@ -22,38 +22,38 @@ impl TestingProposerSlashingBuilder {
         F: Fn(u64, &[u8], Epoch, Domain) -> Signature,
     {
         let slot = Slot::new(0);
-        let shard = 0;
+        let hash_1 = Hash256::from([1; 32]);
+        let hash_2 = Hash256::from([2; 32]);
 
-        let mut proposal_1 = Proposal {
+        let mut header_1 = BeaconBlockHeader {
             slot,
-            shard,
+            previous_block_root: hash_1,
-            block_root: Hash256::from_low_u64_le(1),
+            state_root: hash_1,
+            block_body_root: hash_1,
             signature: Signature::empty_signature(),
         };
 
-        let mut proposal_2 = Proposal {
+        let mut header_2 = BeaconBlockHeader {
-            slot,
+            previous_block_root: hash_2,
-            shard,
+            ..header_1.clone()
-            block_root: Hash256::from_low_u64_le(2),
-            signature: Signature::empty_signature(),
         };
 
-        proposal_1.signature = {
+        header_1.signature = {
-            let message = proposal_1.signed_root();
+            let message = header_1.signed_root();
             let epoch = slot.epoch(spec.slots_per_epoch);
-            signer(proposer_index, &message[..], epoch, Domain::Proposal)
+            signer(proposer_index, &message[..], epoch, Domain::BeaconBlock)
         };
 
-        proposal_2.signature = {
+        header_2.signature = {
-            let message = proposal_2.signed_root();
+            let message = header_2.signed_root();
             let epoch = slot.epoch(spec.slots_per_epoch);
-            signer(proposer_index, &message[..], epoch, Domain::Proposal)
+            signer(proposer_index, &message[..], epoch, Domain::BeaconBlock)
         };
 
         ProposerSlashing {
             proposer_index,
-            proposal_1,
+            header_1,
-            proposal_2,
+            header_2,
         }
     }
 }

eth2/types/src/test_utils/testing_transfer_builder.rs

@@ -10,12 +10,12 @@ pub struct TestingTransferBuilder {
 
 impl TestingTransferBuilder {
     /// Instantiates a new builder.
-    pub fn new(from: u64, to: u64, amount: u64, slot: Slot) -> Self {
+    pub fn new(sender: u64, recipient: u64, amount: u64, slot: Slot) -> Self {
         let keypair = Keypair::random();
 
         let transfer = Transfer {
-            from,
+            sender,
-            to,
+            recipient,
             amount,
             fee: 0,
             slot,