Break down process_final_updates

specs/phase0/beacon-chain.md

@@ -113,7 +113,12 @@
       - [`process_rewards_and_penalties`](#process_rewards_and_penalties)
     - [Registry updates](#registry-updates)
     - [Slashings](#slashings)
-    - [Final updates](#final-updates)
+    - [Eth1 data votes updates](#eth1-data-votes-updates)
+    - [Effective balances updates](#effective-balances-updates)
+    - [Slashings balances updates](#slashings-balances-updates)
+    - [Randao mixes updates](#randao-mixes-updates)
+    - [Historical roots updates](#historical-roots-updates)
+    - [Participation records rotation](#participation-records-rotation)
   - [Block processing](#block-processing)
     - [Block header](#block-header)
     - [RANDAO](#randao)
@@ -1250,7 +1255,12 @@ def process_epoch(state: BeaconState) -> None:
     process_rewards_and_penalties(state)
     process_registry_updates(state)
     process_slashings(state)
-    process_final_updates(state)
+    process_eth1_data_votes_updates(state)
+    process_effective_balances_updates(state)
+    process_slashings_updates(state)
+    process_randao_mixes_updates(state)
+    process_historical_roots_updates(state)
+    process_participation_record_updates(state)
 ```
 
 #### Helper functions
@@ -1557,15 +1567,20 @@ def process_slashings(state: BeaconState) -> None:
             decrease_balance(state, ValidatorIndex(index), penalty)
 ```
 
-#### Final updates
-
+#### Eth1 data votes updates
 ```python
-def process_final_updates(state: BeaconState) -> None:
+def process_eth1_data_votes_updates(state: BeaconState) -> None:
     current_epoch = get_current_epoch(state)
     next_epoch = Epoch(current_epoch + 1)
     # Reset eth1 data votes
     if next_epoch % EPOCHS_PER_ETH1_VOTING_PERIOD == 0:
         state.eth1_data_votes = []
+```
+
+#### Effective balances updates
+
+```python
+def process_effective_balances_updates(state: BeaconState) -> None:
     # Update effective balances with hysteresis
     for index, validator in enumerate(state.validators):
         balance = state.balances[index]
@@ -1577,14 +1592,41 @@ def process_final_updates(state: BeaconState) -> None:
             or validator.effective_balance + UPWARD_THRESHOLD < balance
         ):
             validator.effective_balance = min(balance - balance % EFFECTIVE_BALANCE_INCREMENT, MAX_EFFECTIVE_BALANCE)
+```
+
+#### Slashings balances updates
+
+```python
+def process_slashings_updates(state: BeaconState) -> None:
+    next_epoch = Epoch(get_current_epoch(state) + 1)
     # Reset slashings
     state.slashings[next_epoch % EPOCHS_PER_SLASHINGS_VECTOR] = Gwei(0)
+```
+
+#### Randao mixes updates
+
+```python
+def process_randao_mixes_updates(state: BeaconState) -> None:
+    current_epoch = get_current_epoch(state)
+    next_epoch = Epoch(current_epoch + 1)
     # Set randao mix
     state.randao_mixes[next_epoch % EPOCHS_PER_HISTORICAL_VECTOR] = get_randao_mix(state, current_epoch)
+```
+
+#### Historical roots updates
+```python
+def process_historical_roots_updates(state: BeaconState) -> None:
     # Set historical root accumulator
+    next_epoch = Epoch(get_current_epoch(state) + 1)
     if next_epoch % (SLOTS_PER_HISTORICAL_ROOT // SLOTS_PER_EPOCH) == 0:
         historical_batch = HistoricalBatch(block_roots=state.block_roots, state_roots=state.state_roots)
         state.historical_roots.append(hash_tree_root(historical_batch))
+```
+
+#### Participation records rotation
+
+```python
+def process_participation_record_updates(state: BeaconState) -> None:
     # Rotate current/previous epoch attestations
     state.previous_epoch_attestations = state.current_epoch_attestations
     state.current_epoch_attestations = []