/
spenddag.go
512 lines (404 loc) · 17.5 KB
/
spenddag.go
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package spenddagv1
import (
"github.com/iotaledger/hive.go/ds"
"github.com/iotaledger/hive.go/ds/shrinkingmap"
"github.com/iotaledger/hive.go/ds/walker"
"github.com/iotaledger/hive.go/ierrors"
"github.com/iotaledger/hive.go/lo"
"github.com/iotaledger/hive.go/runtime/syncutils"
"github.com/iotaledger/iota-core/pkg/core/acceptance"
"github.com/iotaledger/iota-core/pkg/core/account"
"github.com/iotaledger/iota-core/pkg/core/vote"
"github.com/iotaledger/iota-core/pkg/core/weight"
"github.com/iotaledger/iota-core/pkg/protocol/engine/mempool/spenddag"
iotago "github.com/iotaledger/iota.go/v4"
)
// SpendDAG represents a data structure that tracks causal relationships between Spends and that allows to
// efficiently manage these Spends (and vote on their fate).
type SpendDAG[SpenderID, ResourceID spenddag.IDType, VoteRank spenddag.VoteRankType[VoteRank]] struct {
// events contains the events of the spenddag.
events *spenddag.Events[SpenderID, ResourceID]
// seatCount is a function that returns the number of seats.
seatCount func() int
// spendersByID is a mapping of SpenderIDs to Spenders.
spendersByID *shrinkingmap.ShrinkingMap[SpenderID, *Spender[SpenderID, ResourceID, VoteRank]]
spendUnhooks *shrinkingmap.ShrinkingMap[SpenderID, func()]
// spendSetsByID is a mapping of ResourceIDs to SpendSets.
spendSetsByID *shrinkingmap.ShrinkingMap[ResourceID, *SpendSet[SpenderID, ResourceID, VoteRank]]
// pendingTasks is a counter that keeps track of the number of pending tasks.
pendingTasks *syncutils.Counter
// mutex is used to synchronize access to the spenddag.
mutex syncutils.RWMutex
// votingMutex is used to synchronize voting for different identities.
votingMutex *syncutils.DAGMutex[account.SeatIndex]
}
// New creates a new spenddag.
func New[SpenderID, ResourceID spenddag.IDType, VoteRank spenddag.VoteRankType[VoteRank]](seatCount func() int) *SpendDAG[SpenderID, ResourceID, VoteRank] {
return &SpendDAG[SpenderID, ResourceID, VoteRank]{
events: spenddag.NewEvents[SpenderID, ResourceID](),
seatCount: seatCount,
spendersByID: shrinkingmap.New[SpenderID, *Spender[SpenderID, ResourceID, VoteRank]](),
spendUnhooks: shrinkingmap.New[SpenderID, func()](),
spendSetsByID: shrinkingmap.New[ResourceID, *SpendSet[SpenderID, ResourceID, VoteRank]](),
pendingTasks: syncutils.NewCounter(),
votingMutex: syncutils.NewDAGMutex[account.SeatIndex](),
}
}
var _ spenddag.SpendDAG[iotago.TransactionID, iotago.OutputID, vote.MockedRank] = &SpendDAG[iotago.TransactionID, iotago.OutputID, vote.MockedRank]{}
// Shutdown shuts down the SpendDAG.
func (c *SpendDAG[SpenderID, ResourceID, VoteRank]) Shutdown() {
c.mutex.Lock()
defer c.mutex.Unlock()
//nolint:revive
c.spendersByID.ForEach(func(spenderID SpenderID, spender *Spender[SpenderID, ResourceID, VoteRank]) bool {
spender.Shutdown()
return true
})
}
// Events returns the events of the spenddag.
func (c *SpendDAG[SpenderID, ResourceID, VoteRank]) Events() *spenddag.Events[SpenderID, ResourceID] {
return c.events
}
// CreateSpender creates a new Spender.
func (c *SpendDAG[SpenderID, ResourceID, VoteRank]) CreateSpender(id SpenderID) {
if func() (created bool) {
c.mutex.RLock()
defer c.mutex.RUnlock()
_, isNewSpend := c.spendersByID.GetOrCreate(id, func() *Spender[SpenderID, ResourceID, VoteRank] {
newSpender := NewSpender[SpenderID, ResourceID, VoteRank](id, weight.New(), c.pendingTasks, acceptance.ThresholdProvider(func() int64 { return int64(c.seatCount()) }))
// attach to the acceptance state updated event and propagate that event to the outside.
// also need to remember the unhook method to properly evict the spender.
c.spendUnhooks.Set(id, newSpender.AcceptanceStateUpdated.Hook(func(_ acceptance.State, newState acceptance.State) {
if newState.IsAccepted() {
c.events.SpenderAccepted.Trigger(newSpender.ID)
return
}
if newState.IsRejected() {
c.events.SpenderRejected.Trigger(newSpender.ID)
}
}).Unhook)
return newSpender
})
return isNewSpend
}() {
c.events.SpenderCreated.Trigger(id)
}
}
func (c *SpendDAG[SpenderID, ResourceID, VoteRank]) UpdateSpentResources(id SpenderID, resourceIDs ds.Set[ResourceID]) error {
joinedSpendSets, err := func() (ds.Set[ResourceID], error) {
c.mutex.RLock()
defer c.mutex.RUnlock()
spender, exists := c.spendersByID.Get(id)
if !exists {
return nil, ierrors.WithMessage(spenddag.ErrEntityEvicted, "spender already evicted")
}
existingSpendSets := c.spendSets(resourceIDs)
return spender.JoinSpendSets(existingSpendSets)
}()
if err != nil {
return ierrors.Wrapf(err, "spender %s failed to join spend sets", id)
}
if !joinedSpendSets.IsEmpty() {
c.events.SpentResourcesAdded.Trigger(id, joinedSpendSets)
}
return nil
}
// ReadConsistent write locks the spenddag and exposes read-only methods to the callback to perform multiple reads while maintaining the same spenddag state.
func (c *SpendDAG[SpenderID, ResourceID, VoteRank]) ReadConsistent(callback func(spenddag spenddag.ReadLockedSpendDAG[SpenderID, ResourceID, VoteRank]) error) error {
c.mutex.Lock()
defer c.mutex.Unlock()
c.pendingTasks.WaitIsZero()
return callback(c)
}
// UpdateSpenderParents updates the parents of the given Spend and returns an error if the operation failed.
func (c *SpendDAG[SpenderID, ResourceID, VoteRank]) UpdateSpenderParents(spenderID SpenderID, addedParentIDs ds.Set[SpenderID], removedParentIDs ds.Set[SpenderID]) error {
newParents := ds.NewSet[SpenderID]()
updated, err := func() (bool, error) {
c.mutex.RLock()
defer c.mutex.RUnlock()
currentSpender, currentSpendExists := c.spendersByID.Get(spenderID)
if !currentSpendExists {
return false, ierrors.WithMessagef(spenddag.ErrEntityEvicted, "tried to modify evicted spend with %s", spenderID)
}
addedParents := ds.NewSet[*Spender[SpenderID, ResourceID, VoteRank]]()
if err := addedParentIDs.ForEach(func(addedParentID SpenderID) error {
// If we cannot load the parent it is because it has been already evicted
if addedParent, addedParentExists := c.spendersByID.Get(addedParentID); addedParentExists {
addedParents.Add(addedParent)
}
return nil
}); err != nil {
return false, err
}
removedParents, err := c.spenders(removedParentIDs, !currentSpender.IsRejected())
if err != nil {
return false, ierrors.Wrap(err, "failed to update spend parents")
}
updated := currentSpender.UpdateParents(addedParents, removedParents)
if updated {
_ = currentSpender.Parents.ForEach(func(parentSpender *Spender[SpenderID, ResourceID, VoteRank]) (err error) {
newParents.Add(parentSpender.ID)
return nil
})
}
return updated, nil
}()
if err != nil {
return err
}
if updated {
c.events.SpenderParentsUpdated.Trigger(spenderID, newParents)
}
return nil
}
// LikedInstead returns the SpenderIDs of the Spenders that are liked instead of the Spenders.
func (c *SpendDAG[SpenderID, ResourceID, VoteRank]) LikedInstead(spenderIDs ds.Set[SpenderID]) ds.Set[SpenderID] {
likedInstead := ds.NewSet[SpenderID]()
spenderIDs.Range(func(spenderID SpenderID) {
if currentSpender, exists := c.spendersByID.Get(spenderID); exists {
if likedSpender := heaviestSpender(currentSpender.LikedInstead()); likedSpender != nil {
likedInstead.Add(likedSpender.ID)
}
}
})
return likedInstead
}
func (c *SpendDAG[SpenderID, ResourceID, VoteRank]) FutureCone(spenderIDs ds.Set[SpenderID]) (futureCone ds.Set[SpenderID]) {
futureCone = ds.NewSet[SpenderID]()
for futureConeWalker := walker.New[*Spender[SpenderID, ResourceID, VoteRank]]().PushAll(lo.Return1(c.spenders(spenderIDs, true)).ToSlice()...); futureConeWalker.HasNext(); {
if spender := futureConeWalker.Next(); futureCone.Add(spender.ID) {
futureConeWalker.PushAll(spender.Children.ToSlice()...)
}
}
return futureCone
}
func (c *SpendDAG[SpenderID, ResourceID, VoteRank]) ConflictingSpenders(spenderID SpenderID) (conflictingSpenders ds.Set[SpenderID], exists bool) {
spender, exists := c.spendersByID.Get(spenderID)
if !exists {
return nil, false
}
conflictingSpenders = ds.NewSet[SpenderID]()
spender.ConflictingSpenders.Range(func(conflictingSpender *Spender[SpenderID, ResourceID, VoteRank]) {
conflictingSpenders.Add(conflictingSpender.ID)
})
return conflictingSpenders, true
}
func (c *SpendDAG[SpenderID, ResourceID, VoteRank]) AllSpendsSupported(seat account.SeatIndex, spenderIDs ds.Set[SpenderID]) bool {
return lo.Return1(c.spenders(spenderIDs, true)).ForEach(func(spender *Spender[SpenderID, ResourceID, VoteRank]) (err error) {
lastVote, exists := spender.LatestVotes.Get(seat)
return lo.Cond(exists && lastVote.IsLiked(), nil, ierrors.Errorf("spender %s is not supported by seat %d", spender.ID, seat))
}) == nil
}
func (c *SpendDAG[SpenderID, ResourceID, VoteRank]) SpenderVoters(spenderID SpenderID) (spendVoters ds.Set[account.SeatIndex]) {
if spender, exists := c.spendersByID.Get(spenderID); exists {
return spender.Weight.Voters.Clone()
}
return ds.NewSet[account.SeatIndex]()
}
func (c *SpendDAG[SpenderID, ResourceID, VoteRank]) SpendSets(spenderID SpenderID) (spendSets ds.Set[ResourceID], exists bool) {
spender, exists := c.spendersByID.Get(spenderID)
if !exists {
return nil, false
}
spendSets = ds.NewSet[ResourceID]()
_ = spender.SpendSets.ForEach(func(spendSet *SpendSet[SpenderID, ResourceID, VoteRank]) error {
spendSets.Add(spendSet.ID)
return nil
})
return spendSets, true
}
func (c *SpendDAG[SpenderID, ResourceID, VoteRank]) SpenderParents(spenderID SpenderID) (spendParents ds.Set[SpenderID], exists bool) {
spender, exists := c.spendersByID.Get(spenderID)
if !exists {
return nil, false
}
spendParents = ds.NewSet[SpenderID]()
_ = spender.Parents.ForEach(func(parent *Spender[SpenderID, ResourceID, VoteRank]) error {
spendParents.Add(parent.ID)
return nil
})
return spendParents, true
}
func (c *SpendDAG[SpenderID, ResourceID, VoteRank]) SpenderChildren(spenderID SpenderID) (spendChildren ds.Set[SpenderID], exists bool) {
spender, exists := c.spendersByID.Get(spenderID)
if !exists {
return nil, false
}
spendChildren = ds.NewSet[SpenderID]()
_ = spender.Children.ForEach(func(parent *Spender[SpenderID, ResourceID, VoteRank]) error {
spendChildren.Add(parent.ID)
return nil
})
return spendChildren, true
}
func (c *SpendDAG[SpenderID, ResourceID, VoteRank]) SpendSetMembers(spendSetID ResourceID) (spenders ds.Set[SpenderID], exists bool) {
spendSet, exists := c.spendSetsByID.Get(spendSetID)
if !exists {
return nil, false
}
spenders = ds.NewSet[SpenderID]()
_ = spendSet.ForEach(func(parent *Spender[SpenderID, ResourceID, VoteRank]) error {
spenders.Add(parent.ID)
return nil
})
return spenders, true
}
func (c *SpendDAG[SpenderID, ResourceID, VoteRank]) SpenderWeight(spenderID SpenderID) int64 {
if spender, exists := c.spendersByID.Get(spenderID); exists {
return spender.Weight.Value().ValidatorsWeight()
}
return 0
}
// CastVotes applies the given votes to the spenddag.
func (c *SpendDAG[SpenderID, ResourceID, VoteRank]) CastVotes(vote *vote.Vote[VoteRank], spenderIDs ds.Set[SpenderID]) error {
c.mutex.RLock()
defer c.mutex.RUnlock()
c.votingMutex.Lock(vote.Voter)
defer c.votingMutex.Unlock(vote.Voter)
supportedSpenders, revokedSpenders, err := c.determineVotes(spenderIDs)
if err != nil {
return ierrors.Wrap(err, "failed to determine votes")
}
for supportedSpender := supportedSpenders.Iterator(); supportedSpender.HasNext(); {
supportedSpender.Next().ApplyVote(vote.WithLiked(true))
}
for revokedSpender := revokedSpenders.Iterator(); revokedSpender.HasNext(); {
revokedSpender.Next().ApplyVote(vote.WithLiked(false))
}
return nil
}
func (c *SpendDAG[SpenderID, ResourceID, VoteRank]) AcceptanceState(spenderIDs ds.Set[SpenderID]) acceptance.State {
lowestObservedState := acceptance.Accepted
if err := spenderIDs.ForEach(func(spenderID SpenderID) error {
spender, exists := c.spendersByID.Get(spenderID)
if !exists {
return ierrors.WithMessage(spenddag.ErrFatal, "tried to retrieve non-existing spend")
}
if spender.IsRejected() {
lowestObservedState = acceptance.Rejected
return spenddag.ErrExpected
}
if spender.IsPending() {
lowestObservedState = acceptance.Pending
}
return nil
}); err != nil && !ierrors.Is(err, spenddag.ErrExpected) {
panic(err)
}
return lowestObservedState
}
func (c *SpendDAG[SpenderID, ResourceID, VoteRank]) SetAccepted(spenderID SpenderID) {
c.mutex.RLock()
defer c.mutex.RUnlock()
if spender, exists := c.spendersByID.Get(spenderID); exists {
spender.setAcceptanceState(acceptance.Accepted)
}
}
// UnacceptedSpends takes a set of SpenderIDs and removes all the accepted Spends (leaving only the
// pending or rejected ones behind).
func (c *SpendDAG[SpenderID, ResourceID, VoteRank]) UnacceptedSpenders(spenderIDs ds.Set[SpenderID]) ds.Set[SpenderID] {
pendingSpenderIDs := ds.NewSet[SpenderID]()
spenderIDs.Range(func(currentSpenderID SpenderID) {
if spender, exists := c.spendersByID.Get(currentSpenderID); exists && !spender.IsAccepted() {
pendingSpenderIDs.Add(currentSpenderID)
}
})
return pendingSpenderIDs
}
// EvictSpend removes spend with given SpenderID from spenddag.
func (c *SpendDAG[SpenderID, ResourceID, VoteRank]) EvictSpender(spenderID SpenderID) {
for _, evictedSpenderID := range func() []SpenderID {
c.mutex.RLock()
defer c.mutex.RUnlock()
return c.evictSpender(spenderID)
}() {
c.events.SpenderEvicted.Trigger(evictedSpenderID)
}
}
func (c *SpendDAG[SpenderID, ResourceID, VoteRank]) evictSpender(spenderID SpenderID) []SpenderID {
// evicting an already evicted spend is fine
spender, exists := c.spendersByID.Get(spenderID)
if !exists {
return nil
}
evictedSpenderIDs := spender.Evict()
// remove the spenders from the spenddag dictionary
for _, evictedSpenderID := range evictedSpenderIDs {
c.spendersByID.Delete(evictedSpenderID)
}
// unhook the spend events and remove the unhook method from the storage
unhookFunc, unhookExists := c.spendUnhooks.Get(spenderID)
if unhookExists {
unhookFunc()
c.spendUnhooks.Delete(spenderID)
}
return evictedSpenderIDs
}
// spenders returns the Spenders that are associated with the given SpenderIDs. If ignoreMissing is set to true, it
// will ignore missing Spenders instead of returning an ErrEntityEvicted error.
func (c *SpendDAG[SpenderID, ResourceID, VoteRank]) spenders(ids ds.Set[SpenderID], ignoreMissing bool) (ds.Set[*Spender[SpenderID, ResourceID, VoteRank]], error) {
spenders := ds.NewSet[*Spender[SpenderID, ResourceID, VoteRank]]()
return spenders, ids.ForEach(func(id SpenderID) (err error) {
existingSpend, exists := c.spendersByID.Get(id)
if exists {
spenders.Add(existingSpend)
}
return lo.Cond(exists || ignoreMissing, nil, ierrors.WithMessagef(spenddag.ErrEntityEvicted, "tried to retrieve a non-existing spend with %s", id))
})
}
// spendSets returns the SpendSets that are associated with the given ResourceIDs. If createMissing is set to
// true, it will create an empty SpendSets for each missing ResourceID.
func (c *SpendDAG[SpenderID, ResourceID, VoteRank]) spendSets(resourceIDs ds.Set[ResourceID]) ds.Set[*SpendSet[SpenderID, ResourceID, VoteRank]] {
spendSets := ds.NewSet[*SpendSet[SpenderID, ResourceID, VoteRank]]()
resourceIDs.Range(func(resourceID ResourceID) {
spendSets.Add(lo.Return1(c.spendSetsByID.GetOrCreate(resourceID, c.spendSetFactory(resourceID))))
})
return spendSets
}
// determineVotes determines the Spends that are supported and revoked by the given SpenderIDs.
func (c *SpendDAG[SpenderID, ResourceID, VoteRank]) determineVotes(spenderIDs ds.Set[SpenderID]) (supportedSpenders ds.Set[*Spender[SpenderID, ResourceID, VoteRank]], revokedSpenders ds.Set[*Spender[SpenderID, ResourceID, VoteRank]], err error) {
supportedSpenders = ds.NewSet[*Spender[SpenderID, ResourceID, VoteRank]]()
revokedSpenders = ds.NewSet[*Spender[SpenderID, ResourceID, VoteRank]]()
revokedWalker := walker.New[*Spender[SpenderID, ResourceID, VoteRank]]()
revokeSpend := func(revokedSpender *Spender[SpenderID, ResourceID, VoteRank]) error {
if revokedSpenders.Add(revokedSpender) {
if supportedSpenders.Has(revokedSpender) {
return ierrors.Errorf("applied conflicting votes (%s is supported and revoked)", revokedSpender.ID)
}
revokedWalker.PushAll(revokedSpender.Children.ToSlice()...)
}
return nil
}
supportedWalker := walker.New[*Spender[SpenderID, ResourceID, VoteRank]]()
supportSpender := func(supportedSpender *Spender[SpenderID, ResourceID, VoteRank]) error {
if supportedSpenders.Add(supportedSpender) {
if err := supportedSpender.ConflictingSpenders.ForEach(revokeSpend); err != nil {
return ierrors.Wrap(err, "failed to collect conflicting spenders")
}
supportedWalker.PushAll(supportedSpender.Parents.ToSlice()...)
}
return nil
}
for supportedWalker.PushAll(lo.Return1(c.spenders(spenderIDs, true)).ToSlice()...); supportedWalker.HasNext(); {
if err := supportSpender(supportedWalker.Next()); err != nil {
return nil, nil, ierrors.Wrap(err, "failed to collect supported spenders")
}
}
for revokedWalker.HasNext() {
if revokedSpender := revokedWalker.Next(); revokedSpenders.Add(revokedSpender) {
revokedWalker.PushAll(revokedSpender.Children.ToSlice()...)
}
}
return supportedSpenders, revokedSpenders, nil
}
func (c *SpendDAG[SpenderID, ResourceID, VoteRank]) spendSetFactory(resourceID ResourceID) func() *SpendSet[SpenderID, ResourceID, VoteRank] {
return func() *SpendSet[SpenderID, ResourceID, VoteRank] {
spendSet := NewSpendSet[SpenderID, ResourceID, VoteRank](resourceID)
spendSet.OnAllMembersEvicted(func(prevValue bool, newValue bool) {
if newValue && !prevValue {
c.spendSetsByID.Delete(spendSet.ID)
}
})
return spendSet
}
}