lbcd/claimtrie/node/node.go
2022-05-26 22:04:33 -07:00

366 lines
10 KiB
Go

package node
import (
"fmt"
"math"
"sort"
"github.com/lbryio/lbcd/claimtrie/change"
"github.com/lbryio/lbcd/claimtrie/param"
)
type Node struct {
BestClaim *Claim // The claim that has most effective amount at the current height.
TakenOverAt int32 // The height at when the current BestClaim took over.
Claims ClaimList // List of all Claims.
Supports ClaimList // List of all Supports, including orphaned ones.
SupportSums map[string]int64
}
// New returns a new node.
func New() *Node {
return &Node{SupportSums: map[string]int64{}}
}
func (n *Node) HasActiveBestClaim() bool {
return n.BestClaim != nil && n.BestClaim.Status == Activated
}
func (n *Node) ApplyChange(chg change.Change, delay int32) error {
visibleAt := chg.VisibleHeight
if visibleAt <= 0 {
visibleAt = chg.Height
}
switch chg.Type {
case change.AddClaim:
c := &Claim{
OutPoint: chg.OutPoint,
Amount: chg.Amount,
ClaimID: chg.ClaimID,
// CreatedAt: chg.Height,
AcceptedAt: chg.Height,
ActiveAt: chg.Height + delay,
VisibleAt: visibleAt,
Sequence: int32(len(n.Claims)),
}
// old := n.Claims.find(byOut(chg.OutPoint)) // TODO: remove this after proving ResetHeight works
// if old != nil {
// return errors.Errorf("CONFLICT WITH EXISTING TXO! Name: %s, Height: %d", chg.Name, chg.Height)
// }
n.Claims = append(n.Claims, c)
case change.SpendClaim:
c := n.Claims.find(byOut(chg.OutPoint))
if c != nil {
c.setStatus(Deactivated)
} else {
LogOnce(fmt.Sprintf("Spending claim but missing existing claim with TXO %s, "+
"Name: %s, ID: %s", chg.OutPoint, chg.Name, chg.ClaimID))
}
// apparently it's legit to be absent in the map:
// 'two' at 481100, 36a719a156a1df178531f3c712b8b37f8e7cc3b36eea532df961229d936272a1:0
case change.UpdateClaim:
// Find and remove the claim, which has just been spent.
c := n.Claims.find(byID(chg.ClaimID))
if c != nil && c.Status == Deactivated {
// Keep its ID, which was generated from the spent claim.
// And update the rest of properties.
c.setOutPoint(chg.OutPoint).SetAmt(chg.Amount)
c.setStatus(Accepted) // it was Deactivated in the spend (but we only activate at the end of the block)
// that's because the old code would put all insertions into the "queue" that was processed at block's end
// This forces us to be newer, which may in an unintentional takeover if there's an older one.
// TODO: reconsider these updates in future hard forks.
c.setAccepted(chg.Height)
c.setActiveAt(chg.Height + delay)
} else {
LogOnce(fmt.Sprintf("Updating claim but missing existing claim with ID %s", chg.ClaimID))
}
case change.AddSupport:
n.Supports = append(n.Supports, &Claim{
OutPoint: chg.OutPoint,
Amount: chg.Amount,
ClaimID: chg.ClaimID,
AcceptedAt: chg.Height,
ActiveAt: chg.Height + delay,
VisibleAt: visibleAt,
})
case change.SpendSupport:
s := n.Supports.find(byOut(chg.OutPoint))
if s != nil {
if s.Status == Activated {
n.SupportSums[s.ClaimID.Key()] -= s.Amount
}
// TODO: we could do without this Deactivated flag if we set expiration instead
// That would eliminate the above Sum update.
// We would also need to track the update situation, though, but that could be done locally.
s.setStatus(Deactivated)
} else {
LogOnce(fmt.Sprintf("Spending support but missing existing claim with TXO %s, "+
"Name: %s, ID: %s", chg.OutPoint, chg.Name, chg.ClaimID))
}
}
return nil
}
// AdjustTo activates claims and computes takeovers until it reaches the specified height.
func (n *Node) AdjustTo(height, maxHeight int32, name []byte) {
changed := n.handleExpiredAndActivated(height) > 0
n.updateTakeoverHeight(height, name, changed)
if maxHeight > height {
for h := n.NextUpdate(); h <= maxHeight; h = n.NextUpdate() {
changed = n.handleExpiredAndActivated(h) > 0
n.updateTakeoverHeight(h, name, changed)
height = h
}
}
}
func (n *Node) updateTakeoverHeight(height int32, name []byte, refindBest bool) {
candidate := n.BestClaim
if refindBest {
candidate = n.findBestClaim() // so expensive...
}
hasCandidate := candidate != nil
hasCurrentWinner := n.HasActiveBestClaim()
takeoverHappening := !hasCandidate || !hasCurrentWinner || candidate.ClaimID != n.BestClaim.ClaimID
if takeoverHappening {
if n.activateAllClaims(height) > 0 {
candidate = n.findBestClaim()
}
}
if !takeoverHappening && height < param.ActiveParams.MaxRemovalWorkaroundHeight {
// This is a super ugly hack to work around bug in old code.
// The bug: un/support a name then update it. This will cause its takeover height to be reset to current.
// This is because the old code would add to the cache without setting block originals when dealing in supports.
_, takeoverHappening = param.TakeoverWorkarounds[fmt.Sprintf("%d_%s", height, name)] // TODO: ditch the fmt call
}
if takeoverHappening {
n.TakenOverAt = height
n.BestClaim = candidate
}
}
func (n *Node) handleExpiredAndActivated(height int32) int {
ot := param.ActiveParams.OriginalClaimExpirationTime
et := param.ActiveParams.ExtendedClaimExpirationTime
fk := param.ActiveParams.ExtendedClaimExpirationForkHeight
expiresAt := func(c *Claim) int32 {
if c.AcceptedAt+ot > fk {
return c.AcceptedAt + et
}
return c.AcceptedAt + ot
}
changes := 0
update := func(items ClaimList, sums map[string]int64) ClaimList {
for i := 0; i < len(items); i++ {
c := items[i]
if c.Status == Accepted && c.ActiveAt <= height && c.VisibleAt <= height {
c.setStatus(Activated)
changes++
if sums != nil {
sums[c.ClaimID.Key()] += c.Amount
}
}
if c.Status == Deactivated || expiresAt(c) <= height {
if i < len(items)-1 {
items[i] = items[len(items)-1]
i--
}
items = items[:len(items)-1]
changes++
if sums != nil && c.Status != Deactivated {
sums[c.ClaimID.Key()] -= c.Amount
}
}
}
return items
}
n.Claims = update(n.Claims, nil)
n.Supports = update(n.Supports, n.SupportSums)
return changes
}
// NextUpdate returns the nearest height in the future that the node should
// be refreshed due to changes of claims or supports.
func (n Node) NextUpdate() int32 {
ot := param.ActiveParams.OriginalClaimExpirationTime
et := param.ActiveParams.ExtendedClaimExpirationTime
fk := param.ActiveParams.ExtendedClaimExpirationForkHeight
expiresAt := func(c *Claim) int32 {
if c.AcceptedAt+ot > fk {
return c.AcceptedAt + et
}
return c.AcceptedAt + ot
}
next := int32(math.MaxInt32)
for _, c := range n.Claims {
ea := expiresAt(c)
if ea < next {
next = ea
}
// if we're not active, we need to go to activeAt unless we're still invisible there
if c.Status == Accepted {
min := c.ActiveAt
if c.VisibleAt > min {
min = c.VisibleAt
}
if min < next {
next = min
}
}
}
for _, s := range n.Supports {
es := expiresAt(s)
if es < next {
next = es
}
if s.Status == Accepted {
min := s.ActiveAt
if s.VisibleAt > min {
min = s.VisibleAt
}
if min < next {
next = min
}
}
}
return next
}
func (n Node) findBestClaim() *Claim {
// WARNING: this method is called billions of times.
// if we just had some easy way to know that our best claim was the first one in the list...
// or it may be faster to cache effective amount in the db at some point.
var best *Claim
var bestAmount int64
for _, candidate := range n.Claims {
// not using switch here for performance reasons
if candidate.Status != Activated {
continue
}
if best == nil {
best = candidate
continue
}
candidateAmount := candidate.Amount + n.SupportSums[candidate.ClaimID.Key()]
if bestAmount <= 0 {
bestAmount = best.Amount + n.SupportSums[best.ClaimID.Key()]
}
switch {
case candidateAmount > bestAmount:
best = candidate
bestAmount = candidateAmount
case candidateAmount < bestAmount:
continue
case candidate.AcceptedAt < best.AcceptedAt:
best = candidate
bestAmount = candidateAmount
case candidate.AcceptedAt > best.AcceptedAt:
continue
case OutPointLess(candidate.OutPoint, best.OutPoint):
best = candidate
bestAmount = candidateAmount
}
}
return best
}
func (n *Node) activateAllClaims(height int32) int {
count := 0
for _, c := range n.Claims {
if c.Status == Accepted && c.ActiveAt > height && c.VisibleAt <= height {
c.setActiveAt(height) // don't necessarily need to change this number?
c.setStatus(Activated)
count++
}
}
for _, s := range n.Supports {
if s.Status == Accepted && s.ActiveAt > height && s.VisibleAt <= height {
s.setActiveAt(height) // don't necessarily need to change this number?
s.setStatus(Activated)
count++
n.SupportSums[s.ClaimID.Key()] += s.Amount
}
}
return count
}
func (n *Node) SortClaimsByBid() {
// purposefully sorting by descent via func parameter order:
sort.Slice(n.Claims, func(j, i int) bool {
// SupportSums only include active values; do the same for amount. No active claim will have a zero amount
iAmount := n.SupportSums[n.Claims[i].ClaimID.Key()]
if n.Claims[i].Status == Activated {
iAmount += n.Claims[i].Amount
}
jAmount := n.SupportSums[n.Claims[j].ClaimID.Key()]
if n.Claims[j].Status == Activated {
jAmount += n.Claims[j].Amount
}
switch {
case iAmount < jAmount:
return true
case iAmount > jAmount:
return false
case n.Claims[i].AcceptedAt > n.Claims[j].AcceptedAt:
return true
case n.Claims[i].AcceptedAt < n.Claims[j].AcceptedAt:
return false
}
return OutPointLess(n.Claims[j].OutPoint, n.Claims[i].OutPoint)
})
}
func (n *Node) Clone() *Node {
clone := New()
if n.SupportSums != nil {
clone.SupportSums = map[string]int64{}
for key, value := range n.SupportSums {
clone.SupportSums[key] = value
}
}
clone.Supports = make(ClaimList, len(n.Supports))
for i, support := range n.Supports {
clone.Supports[i] = &Claim{}
*clone.Supports[i] = *support
}
clone.Claims = make(ClaimList, len(n.Claims))
for i, claim := range n.Claims {
clone.Claims[i] = &Claim{}
*clone.Claims[i] = *claim
}
clone.TakenOverAt = n.TakenOverAt
if n.BestClaim != nil {
clone.BestClaim = clone.Claims.find(byID(n.BestClaim.ClaimID))
}
return clone
}