feat: electra process_operations changes (#1426)

Co-authored-by: Rodrigo Oliveri <rodrigooliveri10@gmail.com>

Author: LeanSerra

electra-gap.md

@@ -73,16 +73,16 @@ The current status of the implementation in the [electra-support](https://github
 - [x] Modified `get_next_sync_committee_indices` ([Spec](docs/specs/electra/beacon-chain.md#modified-get_next_sync_committee_indices), [PR](https://github.com/lambdaclass/lambda_ethereum_consensus/pull/1417))
 - [x] New `get_balance_churn_limit` ([Spec](docs/specs/electra/beacon-chain.md#new-get_balance_churn_limit), [PR](https://github.com/lambdaclass/lambda_ethereum_consensus/pull/1420))
 - [x] New `get_activation_exit_churn_limit` ([Spec](docs/specs/electra/beacon-chain.md#new-get_activation_exit_churn_limit), [PR](https://github.com/lambdaclass/lambda_ethereum_consensus/pull/1420))
-- [ ] New `get_consolidation_churn_limit` ([Spec](docs/specs/electra/beacon-chain.md#new-get_consolidation_churn_limit))
-- [ ] New `get_pending_balance_to_withdraw` ([Spec](docs/specs/electra/beacon-chain.md#new-get_pending_balance_to_withdraw))
+- [x] New `get_consolidation_churn_limit` ([Spec](docs/specs/electra/beacon-chain.md#new-get_consolidation_churn_limit), [PR](https://github.com/lambdaclass/lambda_ethereum_consensus/pull/1426))
+- [x] New `get_pending_balance_to_withdraw` ([Spec](docs/specs/electra/beacon-chain.md#new-get_pending_balance_to_withdraw), [PR](https://github.com/lambdaclass/lambda_ethereum_consensus/pull/1426))
 
 #### Beacon State Mutators (3/6 - 50%)
 
 - [x] Modified `initiate_validator_exit` ([Spec](docs/specs/electra/beacon-chain.md#modified-initiate_validator_exit), [PR](https://github.com/lambdaclass/lambda_ethereum_consensus/pull/1420))
-- [ ] New `switch_to_compounding_validator` ([Spec](docs/specs/electra/beacon-chain.md#new-switch_to_compounding_validator))
-- [ ] New `queue_excess_active_balance` ([Spec](docs/specs/electra/beacon-chain.md#new-queue_excess_active_balance))
+- [x] New `switch_to_compounding_validator` ([Spec](docs/specs/electra/beacon-chain.md#new-switch_to_compounding_validator), [PR](https://github.com/lambdaclass/lambda_ethereum_consensus/pull/1426))
+- [x] New `queue_excess_active_balance` ([Spec](docs/specs/electra/beacon-chain.md#new-queue_excess_active_balance), [PR](https://github.com/lambdaclass/lambda_ethereum_consensus/pull/1426))
 - [x] New `compute_exit_epoch_and_update_churn` ([Spec](docs/specs/electra/beacon-chain.md#new-compute_exit_epoch_and_update_churn), [PR](https://github.com/lambdaclass/lambda_ethereum_consensus/pull/1420))
-- [ ] New `compute_consolidation_epoch_and_update_churn` ([Spec](docs/specs/electra/beacon-chain.md#new-compute_consolidation_epoch_and_update_churn))
+- [x] New `compute_consolidation_epoch_and_update_churn` ([Spec](docs/specs/electra/beacon-chain.md#new-compute_consolidation_epoch_and_update_churn), [PR](https://github.com/lambdaclass/lambda_ethereum_consensus/pull/1426))
 - [x] Modified `slash_validator` ([Spec](docs/specs/electra/beacon-chain.md#modified-slash_validator), [PR](https://github.com/lambdaclass/lambda_ethereum_consensus/pull/1420))
 
 #### Miscellaneous (3/3 - 100%)
@@ -107,12 +107,12 @@ The current status of the implementation in the [electra-support](https://github
 - [ ] Modified `process_withdrawals` ([Spec](docs/specs/electra/beacon-chain.md#modified-process_withdrawals))
 - [ ] Modified `process_execution_payload` ([Spec](docs/specs/electra/beacon-chain.md#modified-process_execution_payload))
 - [x] Modified `process_operations` ([Spec](docs/specs/electra/beacon-chain.md#modified-process_operations), [PR](https://github.com/lambdaclass/lambda_ethereum_consensus/pull/1424))
-- [ ] Modified `process_attestation` ([Spec](docs/specs/electra/beacon-chain.md#modified-process_attestation))
+- [x] Modified `process_attestation` ([Spec](docs/specs/electra/beacon-chain.md#modified-process_attestation), [PR](https://github.com/lambdaclass/lambda_ethereum_consensus/pull/1426))
 - [x] Modified `process_deposit` ([Spec](docs/specs/electra/beacon-chain.md#modified-process_deposit), [PR](https://github.com/lambdaclass/lambda_ethereum_consensus/pull/1424))
-- [ ] Modified `process_voluntary_exit` ([Spec](docs/specs/electra/beacon-chain.md#modified-process_voluntary_exit))
-- [ ] New `process_withdrawal_request` ([Spec](docs/specs/electra/beacon-chain.md#new-process_withdrawal_request))
+- [x] Modified `process_voluntary_exit` ([Spec](docs/specs/electra/beacon-chain.md#modified-process_voluntary_exit), [PR](https://github.com/lambdaclass/lambda_ethereum_consensus/pull/1426))
+- [x] New `process_withdrawal_request` ([Spec](docs/specs/electra/beacon-chain.md#new-process_withdrawal_request), [PR](https://github.com/lambdaclass/lambda_ethereum_consensus/pull/1426))
 - [x] New `process_deposit_request` ([Spec](docs/specs/electra/beacon-chain.md#new-process_deposit_request), [PR](https://github.com/lambdaclass/lambda_ethereum_consensus/pull/1424))
-- [ ] New `process_consolidation_request` ([Spec](docs/specs/electra/beacon-chain.md#new-process_consolidation_request))
+- [x] New `process_consolidation_request` ([Spec](docs/specs/electra/beacon-chain.md#new-process_consolidation_request), [PR](https://github.com/lambdaclass/lambda_ethereum_consensus/pull/1426))
 - [x] New `is_valid_deposit_signature` ([Spec](docs/specs/electra/beacon-chain.md#new-is_valid_deposit_signature), [PR](https://github.com/lambdaclass/lambda_ethereum_consensus/pull/1424))
 - [x] Modified `add_validator_to_registry` ([Spec](docs/specs/electra/beacon-chain.md#modified-add_validator_to_registry), [PR](https://github.com/lambdaclass/lambda_ethereum_consensus/pull/1424))
 - [x] Modified `apply_deposit` ([Spec](docs/specs/electra/beacon-chain.md#modified-apply_deposit), [PR](https://github.com/lambdaclass/lambda_ethereum_consensus/pull/1424))

lib/constants.ex

@@ -151,4 +151,7 @@ defmodule Constants do
 
   @spec consolidation_request_type() :: Types.bytes1()
   def consolidation_request_type(), do: <<2>>
+
+  @spec g2_point_at_infinity() :: Types.bls_signature()
+  def g2_point_at_infinity(), do: <<0xC0, 0::8*95>>
 end

lib/lambda_ethereum_consensus/state_transition/accessors.ex

@@ -653,7 +653,11 @@ defmodule LambdaEthereumConsensus.StateTransition.Accessors do
 
   @spec get_committee_indices(Types.bitvector()) :: Enumerable.t(Types.commitee_index())
   def get_committee_indices(committee_bits) do
-    bitlist = committee_bits |> :binary.bin_to_list() |> Enum.reverse()
+    bitlist =
+      for <<bit::1 <- committee_bits>> do
+        bit
+      end
+      |> Enum.reverse()
 
     for {bit, index} <- Enum.with_index(bitlist), bit == 1, do: index
   end
@@ -682,4 +686,19 @@ defmodule LambdaEthereumConsensus.StateTransition.Accessors do
       get_balance_churn_limit(state)
     )
   end
+
+  @spec get_pending_balance_to_withdraw(BeaconState.t(), Types.validator_index()) :: Types.gwei()
+  def get_pending_balance_to_withdraw(state, validator_index) do
+    for(
+      withdrawal <- state.pending_partial_withdrawals,
+      withdrawal.validator_index == validator_index,
+      do: withdrawal.amount
+    )
+    |> Enum.sum()
+  end
+
+  @spec get_consolidation_churn_limit(BeaconState.t()) :: Types.gwei()
+  def get_consolidation_churn_limit(state) do
+    get_balance_churn_limit(state) - get_activation_exit_churn_limit(state)
+  end
 end

lib/lambda_ethereum_consensus/state_transition/mutators.ex

@@ -218,4 +218,95 @@ defmodule LambdaEthereumConsensus.StateTransition.Mutators do
         earliest_exit_epoch: earliest_exit_epoch
     }
   end
+
+  @spec compute_consolidation_epoch_and_update_churn(Types.BeaconState.t(), Types.gwei()) ::
+          Types.BeaconState.t()
+  def compute_consolidation_epoch_and_update_churn(state, consolidation_balance) do
+    current_epoch = Accessors.get_current_epoch(state)
+
+    earliest_consolidation_epoch =
+      max(state.earliest_consolidation_epoch, Misc.compute_activation_exit_epoch(current_epoch))
+
+    per_epoch_consolidation_churn = Accessors.get_consolidation_churn_limit(state)
+
+    consolidation_balance_to_consume =
+      if state.earliest_consolidation_epoch < earliest_consolidation_epoch do
+        per_epoch_consolidation_churn
+      else
+        state.consolidation_balance_to_consume
+      end
+
+    {earliest_consolidation_epoch, consolidation_balance_to_consume} =
+      if consolidation_balance > consolidation_balance_to_consume do
+        balance_to_process = consolidation_balance - consolidation_balance_to_consume
+        additional_epochs = div(balance_to_process - 1, per_epoch_consolidation_churn) + 1
+
+        {
+          earliest_consolidation_epoch + additional_epochs,
+          consolidation_balance_to_consume + additional_epochs * per_epoch_consolidation_churn
+        }
+      else
+        {earliest_consolidation_epoch, consolidation_balance_to_consume}
+      end
+
+    %BeaconState{
+      state
+      | consolidation_balance_to_consume:
+          consolidation_balance_to_consume - consolidation_balance,
+        earliest_consolidation_epoch: earliest_consolidation_epoch
+    }
+  end
+
+  @spec switch_to_compounding_validator(BeaconState.t(), Types.validator_index()) ::
+          BeaconState.t()
+  def switch_to_compounding_validator(state, index) do
+    validator = Aja.Enum.at(state.validators, index)
+    <<_first_byte::binary-size(1), rest::binary>> = validator.withdrawal_credentials
+
+    withdrawal_credentials =
+      Constants.compounding_withdrawal_prefix() <> rest
+
+    updated_validator = %Validator{
+      validator
+      | withdrawal_credentials: withdrawal_credentials
+    }
+
+    state = %BeaconState{
+      state
+      | validators: Aja.Vector.replace_at(state.validators, index, updated_validator)
+    }
+
+    queue_excess_active_balance(state, index)
+  end
+
+  @spec queue_excess_active_balance(BeaconState.t(), Types.validator_index()) ::
+          BeaconState.t()
+  def queue_excess_active_balance(state, index) do
+    min_activation_balance = ChainSpec.get("MIN_ACTIVATION_BALANCE")
+    balance = Aja.Vector.at(state.balances, index)
+
+    if balance > min_activation_balance do
+      excess_balance = balance - min_activation_balance
+      validator = Aja.Vector.at(state.validators, index)
+
+      updated_balances = Aja.Vector.replace_at(state.balances, index, min_activation_balance)
+      # Use bls.G2_POINT_AT_INFINITY as a signature field placeholder
+      # and GENESIS_SLOT to distinguish from a pending deposit request
+      pending_deposit = %PendingDeposit{
+        pubkey: validator.pubkey,
+        withdrawal_credentials: validator.withdrawal_credentials,
+        amount: excess_balance,
+        signature: Constants.g2_point_at_infinity(),
+        slot: Constants.genesis_slot()
+      }
+
+      %BeaconState{
+        state
+        | balances: updated_balances,
+          pending_deposits: state.pending_deposits ++ [pending_deposit]
+      }
+    else
+      state
+    end
+  end
 end