Refactor x/staking Unbonding Validator Queue

CHANGELOG.md

@@ -200,6 +200,7 @@ invalid or incomplete requests.
 
 ### State Machine Breaking
 
+* (x/staking) [\#6844](https://github.com/cosmos/cosmos-sdk/pull/6844) Validators are now inserted into the unbonding queue based on their unbonding time and height. The relevant keeper APIs are modified to reflect these changes by now also requiring a height.
 * (x/bank) [\#6518](https://github.com/cosmos/cosmos-sdk/pull/6518) Support for global and per-denomination send enabled flags.
   * Existing send_enabled global flag has been moved into a Params structure as `default_send_enabled`.
   * An array of: `{denom: string, enabled: bool}` is added to bank Params to support per-denomination override of global default value.

x/staking/genesis.go

@@ -48,7 +48,7 @@ func InitGenesis(
 
 		// update timeslice if necessary
 		if validator.IsUnbonding() {
-			keeper.InsertValidatorQueue(ctx, validator)
+			keeper.InsertUnbondingValidatorQueue(ctx, validator)
 		}
 
 		switch validator.GetStatus() {

x/staking/keeper/delegation_test.go

@@ -528,7 +528,7 @@ func TestUndelegateFromUnbondedValidator(t *testing.T) {
 
 	// unbond the validator
 	ctx = ctx.WithBlockTime(validator.UnbondingTime)
-	app.StakingKeeper.UnbondAllMatureValidatorQueue(ctx)
+	app.StakingKeeper.UnbondAllMatureValidators(ctx)
 
 	// Make sure validator is still in state because there is still an outstanding delegation
 	validator, found = app.StakingKeeper.GetValidator(ctx, addrVals[0])
@@ -619,7 +619,7 @@ func TestUnbondingAllDelegationFromValidator(t *testing.T) {
 
 	// unbond the validator
 	ctx = ctx.WithBlockTime(validator.UnbondingTime)
-	app.StakingKeeper.UnbondAllMatureValidatorQueue(ctx)
+	app.StakingKeeper.UnbondAllMatureValidators(ctx)
 
 	// validator should now be deleted from state
 	_, found = app.StakingKeeper.GetValidator(ctx, addrVals[0])

x/staking/keeper/val_state_change.go

@@ -26,8 +26,8 @@ func (k Keeper) BlockValidatorUpdates(ctx sdk.Context) []abci.ValidatorUpdate {
 	// UnbondAllMatureValidatorQueue).
 	validatorUpdates := k.ApplyAndReturnValidatorSetUpdates(ctx)
 
-	// Unbond all mature validators from the unbonding queue.
-	k.UnbondAllMatureValidatorQueue(ctx)
+	// unbond all mature validators from the unbonding queue
+	k.UnbondAllMatureValidators(ctx)
 
 	// Remove all mature unbonding delegations from the ubd queue.
 	matureUnbonds := k.DequeueAllMatureUBDQueue(ctx, ctx.BlockHeader().Time)
@@ -283,7 +283,7 @@ func (k Keeper) beginUnbondingValidator(ctx sdk.Context, validator types.Validat
 	k.SetValidatorByPowerIndex(ctx, validator)
 
 	// Adds to unbonding validator queue
-	k.InsertValidatorQueue(ctx, validator)
+	k.InsertUnbondingValidatorQueue(ctx, validator)
 
 	// trigger hook
 	k.AfterValidatorBeginUnbonding(ctx, validator.GetConsAddr(), validator.OperatorAddress)

x/staking/keeper/validator.go

@@ -358,112 +358,118 @@ func (k Keeper) GetLastValidators(ctx sdk.Context) (validators []types.Validator
 	return validators[:i] // trim
 }
 
-//_______________________________________________________________________
-// Validator Queue
-
-// gets a specific validator queue timeslice. A timeslice is a slice of ValAddresses corresponding to unbonding validators
-// that expire at a certain time.
-func (k Keeper) GetValidatorQueueTimeSlice(ctx sdk.Context, timestamp time.Time) []sdk.ValAddress {
+// GetUnbondingValidators returns a slice of mature validator addresses that
+// complete their unbonding at a given time and height.
+func (k Keeper) GetUnbondingValidators(ctx sdk.Context, endTime time.Time, endHeight int64) []sdk.ValAddress {
 	store := ctx.KVStore(k.storeKey)
 
-	bz := store.Get(types.GetValidatorQueueTimeKey(timestamp))
+	bz := store.Get(types.GetValidatorQueueKey(endTime, endHeight))
 	if bz == nil {
 		return []sdk.ValAddress{}
 	}
 
-	va := sdk.ValAddresses{}
-	k.cdc.MustUnmarshalBinaryBare(bz, &va)
+	addrs := sdk.ValAddresses{}
+	k.cdc.MustUnmarshalBinaryBare(bz, &addrs)
 
-	return va.Addresses
+	return addrs.Addresses
 }
 
-// Sets a specific validator queue timeslice.
-func (k Keeper) SetValidatorQueueTimeSlice(ctx sdk.Context, timestamp time.Time, keys []sdk.ValAddress) {
+// SetUnbondingValidatorsQueue sets a given slice of validator addresses into
+// the unbonding validator queue by a given height and time.
+func (k Keeper) SetUnbondingValidatorsQueue(ctx sdk.Context, endTime time.Time, endHeight int64, addrs []sdk.ValAddress) {
 	store := ctx.KVStore(k.storeKey)
-	bz := k.cdc.MustMarshalBinaryBare(&sdk.ValAddresses{Addresses: keys})
-	store.Set(types.GetValidatorQueueTimeKey(timestamp), bz)
+	bz := k.cdc.MustMarshalBinaryBare(&sdk.ValAddresses{Addresses: addrs})
+	store.Set(types.GetValidatorQueueKey(endTime, endHeight), bz)
 }
 
-// Deletes a specific validator queue timeslice.
-func (k Keeper) DeleteValidatorQueueTimeSlice(ctx sdk.Context, timestamp time.Time) {
-	store := ctx.KVStore(k.storeKey)
-	store.Delete(types.GetValidatorQueueTimeKey(timestamp))
+// InsertUnbondingValidatorQueue inserts a given unbonding validator address into
+// the unbonding validator queue for a given height and time.
+func (k Keeper) InsertUnbondingValidatorQueue(ctx sdk.Context, val types.Validator) {
+	addrs := k.GetUnbondingValidators(ctx, val.UnbondingTime, val.UnbondingHeight)
+	addrs = append(addrs, val.OperatorAddress)
+	k.SetUnbondingValidatorsQueue(ctx, val.UnbondingTime, val.UnbondingHeight, addrs)
 }
 
-// Insert an validator address to the appropriate timeslice in the validator queue
-func (k Keeper) InsertValidatorQueue(ctx sdk.Context, val types.Validator) {
-	timeSlice := k.GetValidatorQueueTimeSlice(ctx, val.UnbondingTime)
-	timeSlice = append(timeSlice, val.OperatorAddress)
-	k.SetValidatorQueueTimeSlice(ctx, val.UnbondingTime, timeSlice)
+// DeleteValidatorQueueTimeSlice deletes all entries in the queue indexed by a
+// given height and time.
+func (k Keeper) DeleteValidatorQueueTimeSlice(ctx sdk.Context, endTime time.Time, endHeight int64) {
+	store := ctx.KVStore(k.storeKey)
+	store.Delete(types.GetValidatorQueueKey(endTime, endHeight))
 }
 
-// Delete a validator address from the validator queue
+// DeleteValidatorQueue removes a validator by address from the unbonding queue
+// indexed by a given height and time.
 func (k Keeper) DeleteValidatorQueue(ctx sdk.Context, val types.Validator) {
-	timeSlice := k.GetValidatorQueueTimeSlice(ctx, val.UnbondingTime)
-	newTimeSlice := []sdk.ValAddress{}
+	addrs := k.GetUnbondingValidators(ctx, val.UnbondingTime, val.UnbondingHeight)
+	newAddrs := []sdk.ValAddress{}
 
-	for _, addr := range timeSlice {
+	for _, addr := range addrs {
 		if !bytes.Equal(addr, val.OperatorAddress) {
-			newTimeSlice = append(newTimeSlice, addr)
+			newAddrs = append(newAddrs, addr)
 		}
 	}
 
-	if len(newTimeSlice) == 0 {
-		k.DeleteValidatorQueueTimeSlice(ctx, val.UnbondingTime)
+	if len(newAddrs) == 0 {
+		k.DeleteValidatorQueueTimeSlice(ctx, val.UnbondingTime, val.UnbondingHeight)
 	} else {
-		k.SetValidatorQueueTimeSlice(ctx, val.UnbondingTime, newTimeSlice)
+		k.SetUnbondingValidatorsQueue(ctx, val.UnbondingTime, val.UnbondingHeight, newAddrs)
 	}
 }
 
-// Returns all the validator queue timeslices from time 0 until endTime
-func (k Keeper) ValidatorQueueIterator(ctx sdk.Context, endTime time.Time) sdk.Iterator {
+// ValidatorQueueIterator returns an interator ranging over validators that are
+// unbonding whose unbonding completion occurs at the given height and time.
+func (k Keeper) ValidatorQueueIterator(ctx sdk.Context, endTime time.Time, endHeight int64) sdk.Iterator {
 	store := ctx.KVStore(k.storeKey)
-	return store.Iterator(types.ValidatorQueueKey, sdk.InclusiveEndBytes(types.GetValidatorQueueTimeKey(endTime)))
-}
-
-// Returns a concatenated list of all the timeslices before currTime, and deletes the timeslices from the queue
-func (k Keeper) GetAllMatureValidatorQueue(ctx sdk.Context, currTime time.Time) (matureValsAddrs []sdk.ValAddress) {
-	// gets an iterator for all timeslices from time 0 until the current Blockheader time
-	validatorTimesliceIterator := k.ValidatorQueueIterator(ctx, ctx.BlockHeader().Time)
-	defer validatorTimesliceIterator.Close()
-
-	for ; validatorTimesliceIterator.Valid(); validatorTimesliceIterator.Next() {
-		timeslice := sdk.ValAddresses{}
-		k.cdc.MustUnmarshalBinaryBare(validatorTimesliceIterator.Value(), &timeslice)
-
-		matureValsAddrs = append(matureValsAddrs, timeslice.Addresses...)
-	}
-
-	return matureValsAddrs
+	return store.Iterator(types.ValidatorQueueKey, sdk.InclusiveEndBytes(types.GetValidatorQueueKey(endTime, endHeight)))
 }
 
-// Unbonds all the unbonding validators that have finished their unbonding period
-func (k Keeper) UnbondAllMatureValidatorQueue(ctx sdk.Context) {
+// UnbondAllMatureValidators unbonds all the mature unbonding validators that
+// have finished their unbonding period.
+func (k Keeper) UnbondAllMatureValidators(ctx sdk.Context) {
 	store := ctx.KVStore(k.storeKey)
 
-	validatorTimesliceIterator := k.ValidatorQueueIterator(ctx, ctx.BlockHeader().Time)
-	defer validatorTimesliceIterator.Close()
-
-	for ; validatorTimesliceIterator.Valid(); validatorTimesliceIterator.Next() {
-		timeslice := sdk.ValAddresses{}
-		k.cdc.MustUnmarshalBinaryBare(validatorTimesliceIterator.Value(), &timeslice)
-
-		for _, valAddr := range timeslice.Addresses {
-			val, found := k.GetValidator(ctx, valAddr)
-			if !found {
-				panic("validator in the unbonding queue was not found")
-			}
+	blockTime := ctx.BlockTime()
+	blockHeight := ctx.BlockHeight()
+
+	// unbondingValIterator will contains all validator addresses indexed under
+	// the ValidatorQueueKey prefix. Note, the entire index key is composed as
+	// ValidatorQueueKey | timeBzLen (8-byte big endian) | timeBz | heightBz (8-byte big endian),
+	// so it may be possible that certain validator addresses that are iterated
+	// over are not ready to unbond, so an explicit check is required.
+	unbondingValIterator := k.ValidatorQueueIterator(ctx, blockTime, blockHeight)
+	defer unbondingValIterator.Close()
+
+	for ; unbondingValIterator.Valid(); unbondingValIterator.Next() {
+		key := unbondingValIterator.Key()
+		keyTime, keyHeight, err := types.ParseValidatorQueueKey(key)
+		if err != nil {
+			panic(fmt.Errorf("failed to parse unbonding key: %w", err))
+		}
 
-			if !val.IsUnbonding() {
-				panic("unexpected validator in unbonding queue; status was not unbonding")
+		// All addresses for the given key have the same unbonding height and time.
+		// We only unbond if the height and time are less than the current height
+		// and time.
+		if keyHeight <= blockHeight && (keyTime.Before(blockTime) || keyTime.Equal(blockTime)) {
+			addrs := sdk.ValAddresses{}
+			k.cdc.MustUnmarshalBinaryBare(unbondingValIterator.Value(), &addrs)
+
+			for _, valAddr := range addrs.Addresses {
+				val, found := k.GetValidator(ctx, valAddr)
+				if !found {
+					panic("validator in the unbonding queue was not found")
+				}
+
+				if !val.IsUnbonding() {
+					panic("unexpected validator in unbonding queue; status was not unbonding")
+				}
+
+				val = k.UnbondingToUnbonded(ctx, val)
+				if val.GetDelegatorShares().IsZero() {
+					k.RemoveValidator(ctx, val.OperatorAddress)
+				}
 			}
 
-			val = k.UnbondingToUnbonded(ctx, val)
-			if val.GetDelegatorShares().IsZero() {
-				k.RemoveValidator(ctx, val.OperatorAddress)
-			}
+			store.Delete(key)
 		}
-
-		store.Delete(validatorTimesliceIterator.Key())
 	}
 }

x/staking/types/keys.go

@@ -1,7 +1,9 @@
 package types
 
 import (
+	"bytes"
 	"encoding/binary"
+	"fmt"
 	"strconv"
 	"time"
 
@@ -120,13 +122,49 @@ func ParseValidatorPowerRankKey(key []byte) (operAddr []byte) {
 	return operAddr
 }
 
-// gets the prefix for all unbonding delegations from a delegator
-func GetValidatorQueueTimeKey(timestamp time.Time) []byte {
-	bz := sdk.FormatTimeBytes(timestamp)
-	return append(ValidatorQueueKey, bz...)
+// GetValidatorQueueKey returns the prefix key used for getting a set of unbonding
+// validators whose unbonding completion occurs at the given time and height.
+func GetValidatorQueueKey(timestamp time.Time, height int64) []byte {
+	heightBz := sdk.Uint64ToBigEndian(uint64(height))
+	timeBz := sdk.FormatTimeBytes(timestamp)
+	timeBzL := len(timeBz)
+	prefixL := len(ValidatorQueueKey)
+
+	bz := make([]byte, prefixL+8+timeBzL+8)
+
+	// copy the prefix
+	copy(bz[:prefixL], ValidatorQueueKey)
+
+	// copy the encoded time bytes length
+	copy(bz[prefixL:prefixL+8], sdk.Uint64ToBigEndian(uint64(timeBzL)))
+
+	// copy the encoded time bytes
+	copy(bz[prefixL+8:prefixL+8+timeBzL], timeBz)
+
+	// copy the encoded height
+	copy(bz[prefixL+8+timeBzL:], heightBz)
+
+	return bz
 }
 
-//______________________________________________________________________________
+// ParseValidatorQueueKey returns the encoded time and height from a key created
+// from GetValidatorQueueKey.
+func ParseValidatorQueueKey(bz []byte) (time.Time, int64, error) {
+	prefixL := len(ValidatorQueueKey)
+	if prefix := bz[:prefixL]; !bytes.Equal(prefix, ValidatorQueueKey) {
+		return time.Time{}, 0, fmt.Errorf("invalid prefix; expected: %X, got: %X", ValidatorQueueKey, prefix)
+	}
+
+	timeBzL := sdk.BigEndianToUint64(bz[prefixL : prefixL+8])
+	ts, err := sdk.ParseTimeBytes(bz[prefixL+8 : prefixL+8+int(timeBzL)])
+	if err != nil {
+		return time.Time{}, 0, err
+	}
+
+	height := sdk.BigEndianToUint64(bz[prefixL+8+int(timeBzL):])
+
+	return ts, int64(height), nil
+}
 
 // gets the key for delegator bond with validator
 // VALUE: staking/Delegation
@@ -139,8 +177,6 @@ func GetDelegationsKey(delAddr sdk.AccAddress) []byte {
 	return append(DelegationKey, delAddr.Bytes()...)
 }
 
-//______________________________________________________________________________
-
 // gets the key for an unbonding delegation by delegator and validator addr
 // VALUE: staking/UnbondingDelegation
 func GetUBDKey(delAddr sdk.AccAddress, valAddr sdk.ValAddress) []byte {
@@ -168,8 +204,6 @@ func GetUBDKeyFromValIndexKey(indexKey []byte) []byte {
 	return GetUBDKey(delAddr, valAddr)
 }
 
-//______________
-
 // gets the prefix for all unbonding delegations from a delegator
 func GetUBDsKey(delAddr sdk.AccAddress) []byte {
 	return append(UnbondingDelegationKey, delAddr.Bytes()...)
@@ -186,10 +220,8 @@ func GetUnbondingDelegationTimeKey(timestamp time.Time) []byte {
 	return append(UnbondingQueueKey, bz...)
 }
 
-//________________________________________________________________________________
-
-// gets the key for a redelegation
-// VALUE: staking/RedelegationKey
+// GetREDKey returns a key prefix for indexing a redelegation from a delegator
+// and source validator to a destination validator.
 func GetREDKey(delAddr sdk.AccAddress, valSrcAddr, valDstAddr sdk.ValAddress) []byte {
 	key := make([]byte, 1+sdk.AddrLen*3)
 
@@ -258,38 +290,38 @@ func GetREDKeyFromValDstIndexKey(indexKey []byte) []byte {
 	return GetREDKey(delAddr, valSrcAddr, valDstAddr)
 }
 
-// gets the prefix for all unbonding delegations from a delegator
+// GetRedelegationTimeKey returns a key prefix for indexing an unbonding
+// redelegation based on a completion time.
 func GetRedelegationTimeKey(timestamp time.Time) []byte {
 	bz := sdk.FormatTimeBytes(timestamp)
 	return append(RedelegationQueueKey, bz...)
 }
 
-//______________
-
-// gets the prefix keyspace for redelegations from a delegator
+// GetREDsKey returns a key prefix for indexing a redelegation from a delegator
+// address.
 func GetREDsKey(delAddr sdk.AccAddress) []byte {
 	return append(RedelegationKey, delAddr.Bytes()...)
 }
 
-// gets the prefix keyspace for all redelegations redelegating away from a source validator
+// GetREDsFromValSrcIndexKey returns a key prefix for indexing a redelegation to
+// a source validator.
 func GetREDsFromValSrcIndexKey(valSrcAddr sdk.ValAddress) []byte {
 	return append(RedelegationByValSrcIndexKey, valSrcAddr.Bytes()...)
 }
 
-// gets the prefix keyspace for all redelegations redelegating towards a destination validator
+// GetREDsToValDstIndexKey returns a key prefix for indexing a redelegation to a
+// destination (target) validator.
 func GetREDsToValDstIndexKey(valDstAddr sdk.ValAddress) []byte {
 	return append(RedelegationByValDstIndexKey, valDstAddr.Bytes()...)
 }
 
-// gets the prefix keyspace for all redelegations redelegating towards a destination validator
-// from a particular delegator
+// GetREDsByDelToValDstIndexKey returns a key prefix for indexing a redelegation
+// from an address to a source validator.
 func GetREDsByDelToValDstIndexKey(delAddr sdk.AccAddress, valDstAddr sdk.ValAddress) []byte {
 	return append(GetREDsToValDstIndexKey(valDstAddr), delAddr.Bytes()...)
 }
 
-//________________________________________________________________________________
-
-// GetHistoricalInfoKey gets the key for the historical info
+// GetHistoricalInfoKey returns a key prefix for indexing HistoricalInfo objects.
 func GetHistoricalInfoKey(height int64) []byte {
 	return append(HistoricalInfoKey, []byte(strconv.FormatInt(height, 10))...)
 }