feat(withdrawal): forced withdrawal

examples/berad/pkg/state-transition/interfaces.go

@@ -93,6 +93,9 @@ type ReadOnlyBeaconState[
 	ValidatorIndexByCometBFTAddress(
 		cometBFTAddress []byte,
 	) (math.ValidatorIndex, error)
+	ValidatorIndexByPubkey(
+		crypto.BLSPubkey,
+	) (math.ValidatorIndex, error)
 }
 
 // WriteOnlyBeaconState is the interface for a write-only beacon state.
@@ -106,6 +109,7 @@ type WriteOnlyBeaconState[
 
 	DecreaseBalance(math.ValidatorIndex, math.Gwei) error
 	IncreaseBalance(math.ValidatorIndex, math.Gwei) error
+	SetWithdrawalValidator(math.ValidatorIndex) error
 	SetEth1DepositIndex(uint64) error
 	SetFork(ForkT) error
 	SetGenesisValidatorsRoot(root common.Root) error

examples/berad/pkg/state-transition/state_processor_staking.go

@@ -270,10 +270,21 @@ func (sp *StateProcessor[
 func (sp *StateProcessor[
 	_, _, _, BeaconStateT, _, _, _, _, _, _, _, _, _, _, _, _,
 ]) processForcedWithdrawals(
-	_ BeaconStateT,
-	_ transition.ValidatorUpdates,
+	st BeaconStateT,
+	valUpdates transition.ValidatorUpdates,
 ) error {
-	// TODO: Implement this function.
+	// Process the forced withdrawals.
+	for _, valUpdate := range valUpdates {
+		idx, err := st.ValidatorIndexByPubkey(valUpdate.Pubkey)
+		if err != nil {
+			return err
+		}
+
+		// Set the validator's effective balance to 0.
+		if err = st.SetWithdrawalValidator(idx); err != nil {
+			return err
+		}
+	}
 	return nil
 }
 

mod/storage/pkg/beacondb/keys/keys.go

@@ -43,6 +43,7 @@ const (
 	GenesisValidatorsRootPrefix
 	NextWithdrawalIndexPrefix
 	NextWithdrawalValidatorIndexPrefix
+	WithdrawalValidatorsPrefix
 	ForkPrefix
 )
 
@@ -70,5 +71,6 @@ const (
 	GenesisValidatorsRootPrefixHumanReadable            = "GenesisValidatorsRootPrefix"
 	NextWithdrawalIndexPrefixHumanReadable              = "NextWithdrawalIndexPrefix"
 	NextWithdrawalValidatorIndexPrefixHumanReadable     = "NextWithdrawalValidatorIndexPrefix"
+	WithdrawalValidatorsPrefixHumanReadable             = "WithdrawalValidatorsPrefix"
 	ForkPrefixHumanReadable                             = "ForkPrefix"
 )

mod/storage/pkg/beacondb/kvstore.go

@@ -98,6 +98,11 @@ type KVStore[
 	// nextWithdrawalValidatorIndex stores the next withdrawal validator index
 	// for each validator.
 	nextWithdrawalValidatorIndex sdkcollections.Item[uint64]
+	// withdrawalValidators stores the list of validators that need to be
+	// withdrawn.
+	withdrawalValidators *sdkcollections.IndexedMap[
+		uint64, ValidatorT, index.ValidatorsIndex[ValidatorT],
+	]
 	// Randomness
 	// randaoMix stores the randao mix for the current epoch.
 	randaoMix sdkcollections.Map[uint64, []byte]
@@ -253,6 +258,14 @@ func New[
 			keys.NextWithdrawalValidatorIndexPrefixHumanReadable,
 			sdkcollections.Uint64Value,
 		),
+		withdrawalValidators: sdkcollections.NewIndexedMap(
+			schemaBuilder,
+			sdkcollections.NewPrefix([]byte{keys.WithdrawalValidatorsPrefix}),
+			keys.WithdrawalValidatorsPrefixHumanReadable,
+			sdkcollections.Uint64Key,
+			encoding.SSZValueCodec[ValidatorT]{},
+			index.NewValidatorsIndex[ValidatorT](schemaBuilder),
+		),
 		totalSlashing: sdkcollections.NewItem(
 			schemaBuilder,
 			sdkcollections.NewPrefix([]byte{keys.TotalSlashingPrefix}),

mod/storage/pkg/beacondb/registry.go

@@ -50,7 +50,7 @@ func (kv *KVStore[
 	BeaconBlockHeaderT, Eth1DataT, ExecutionPayloadHeaderT,
 	ForkT, ValidatorT, ValidatorsT,
 ]) AddValidatorBartio(val ValidatorT) error {
-	// Get the ne
+	// Get the next validator index from the sequence.
 	idx, err := kv.validatorIndex.Next(kv.ctx)
 	if err != nil {
 		return err
@@ -285,3 +285,38 @@ func (kv *KVStore[
 		},
 	)
 }
+
+func (kv *KVStore[
+	BeaconBlockHeaderT, Eth1DataT, ExecutionPayloadHeaderT,
+	ForkT, ValidatorT, ValidatorsT,
+]) SetWithdrawalValidator(
+	idx math.ValidatorIndex,
+) error {
+	val, err := kv.ValidatorByIndex(idx)
+	if err != nil {
+		return err
+	}
+
+	// Set the withdrawal validator.
+	if err = kv.withdrawalValidators.Set(kv.ctx, idx.Unwrap(), val); err != nil {
+		return err
+	}
+
+	// Get the next withdrawal index.
+	withdrawalIdx, err := kv.nextWithdrawalIndex.Get(kv.ctx)
+	if err != nil {
+		return err
+	}
+
+	// Increment the withdrawal index.
+	if err = kv.nextWithdrawalIndex.Set(kv.ctx, withdrawalIdx+1); err != nil {
+		return err
+	}
+
+	// Set the validator's balance to 0.
+	val.SetEffectiveBalance(0)
+	if err = kv.validators.Set(kv.ctx, idx.Unwrap(), val); err != nil {
+		return err
+	}
+	return kv.SetBalance(idx, 0)
+}

mod/storage/pkg/beacondb/types.go

@@ -37,4 +37,6 @@ type Validator[SelfT any] interface {
 	GetEffectiveBalance() math.Gwei
 	// IsActive checks if the validator is active at the given epoch.
 	IsActive(epoch math.Epoch) bool
+	// SetEffectiveBalance sets the effective balance of the validator.
+	SetEffectiveBalance(math.Gwei)
 }