Fork mechanics and median time in vectorindex

src/inter/idx/index.go

@@ -11,6 +11,9 @@ type (
 	// Event numeration.
 	Event uint64
 
+	// Member numeration.
+	Member uint64
+
 	// Txn numeration.
 	Txn uint64
 
@@ -28,6 +31,11 @@ func (e Event) Bytes() []byte {
 	return common.IntToBytes(uint64(e))
 }
 
+// Bytes gets the byte representation of the index.
+func (m Member) Bytes() []byte {
+	return common.IntToBytes(uint64(m))
+}
+
 // Bytes gets the byte representation of the index.
 func (t Txn) Bytes() []byte {
 	return common.IntToBytes(uint64(t))
@@ -47,6 +55,15 @@ func BytesToEvent(b []byte) Event {
 	return res
 }
 
+// BytesToMember converts bytes to member index.
+func BytesToMember(b []byte) Member {
+	var res Member
+	for i := 0; i < len(b); i++ {
+		res += Member(b[i]) << uint(i*8)
+	}
+	return res
+}
+
 // BytesToTxn converts bytes to transaction index.
 func BytesToTxn(b []byte) Txn {
 	var res Txn

src/posposet/event_ordering.go

@@ -56,52 +56,26 @@ func (p *Poset) fareOrdering(frame idx.Frame, sfWitness hash.Event, unordered in
 		selectedEvents = selectedEvents[:nodeCount-1]
 	}
 
-	// 3. Get Stake from each creator
-	stakes := map[hash.Peer]inter.Stake{}
-	var jointStake inter.Stake
-	for _, event := range selectedEvents {
-		stake := p.StakeOf(event.Creator)
-
-		stakes[event.Creator] = stake
-		jointStake += stake
-	}
-
-	halfStake := jointStake / 2
-
-	// 4. Calculate weighted median
-	var currStake inter.Stake
-	var median *inter.Event
-	for _, event := range selectedEvents {
-		currStake += stakes[event.Creator]
-		if currStake < halfStake {
-			continue
-		}
-
-		if median == nil {
-			median = event
-		}
-	}
-
-	highestTimestamp := selectedEvents[len(selectedEvents)-1].LamportTime
-	lowestTimestamp := selectedEvents[0].LamportTime
+	highestTimestamp := selectedEvents[len(selectedEvents)-1].LamportTime // TODO .ClaimedTime
+	lowestTimestamp := selectedEvents[0].LamportTime                      // TODO .ClaimedTime
 
-	// 5. Calculate time ratio & time offset
+	// 3. Calculate time ratio & time offset
 	if p.LastConsensusTime == 0 {
 		p.LastConsensusTime = genesisTimestamp
 	}
 
-	frameTimePeriod := inter.MaxTimestamp(median.LamportTime-p.LastConsensusTime, 1)
+	frameTimePeriod := inter.MaxTimestamp(p.vi.MedianTime(sfWitness, genesisTimestamp)-p.LastConsensusTime, 1)
 	frameLamportPeriod := inter.MaxTimestamp(highestTimestamp-lowestTimestamp, 1)
 
 	timeRatio := inter.MaxTimestamp(frameTimePeriod/frameLamportPeriod, 1)
 
 	lowestConsensusTime := p.LastConsensusTime + timeRatio
 	timeOffset := lowestConsensusTime - lowestTimestamp*timeRatio
 
-	// 6. Calculate consensus timestamp
+	// 4. Calculate consensus timestamp
 	p.LastConsensusTime = p.input.GetEvent(sfWitness).LamportTime*timeRatio + timeOffset
 
-	// 7. Save new timeRatio & timeOffset to frame
+	// 5. Save new timeRatio & timeOffset to frame
 	p.frames[frame].SetTimes(timeOffset, timeRatio)
 
 	return sortEvents(unordered)

src/posposet/internal/members.go

@@ -1,6 +1,7 @@
 package internal
 
 import (
+	"github.com/Fantom-foundation/go-lachesis/src/inter/idx"
 	"sort"
 
 	"github.com/Fantom-foundation/go-lachesis/src/hash"
@@ -19,18 +20,22 @@ type (
 func (mm *Members) Add(addr hash.Peer, stake inter.Stake) {
 	(*mm)[addr] = stake
 }
-
-// Top gets top subset.
-func (mm Members) Top() Members {
-	top := make(members, 0, len(mm))
+func (mm Members) sortedArray() members {
+	array := make(members, 0, len(mm))
 	for n, s := range mm {
-		top = append(top, member{
+		array = append(array, member{
 			Addr:  n,
 			Stake: s,
 		})
 	}
+	sort.Sort(array)
+	return array
+}
+
+// Top gets top subset.
+func (mm Members) Top() Members {
+	top := mm.sortedArray()
 
-	sort.Sort(top)
 	if len(top) > MembersCount {
 		top = top[:MembersCount]
 	}
@@ -43,6 +48,15 @@ func (mm Members) Top() Members {
 	return res
 }
 
+// Deterministic total order of members.
+func (mm Members) Idxs() map[hash.Peer]idx.Member {
+	idxs := make(map[hash.Peer]idx.Member, len(mm))
+	for i, m := range mm.sortedArray() {
+		idxs[m.Addr] = idx.Member(i)
+	}
+	return idxs
+}
+
 // Quorum limit of members.
 func (mm Members) Quorum() inter.Stake {
 	return mm.TotalStake()*2/3 + 1

src/posposet/poset.go

@@ -253,7 +253,7 @@ func (p *Poset) superFrameSealed(sfWitness hash.Event) bool {
 // and returns frame where event is root.
 // It is not safe for concurrent use.
 func (p *Poset) checkIfRoot(e *Event) (frame *Frame, isRoot bool) {
-	p.strongly.Cache(e.Event)
+	p.vi.Add(e.Event)
 
 	var frameI idx.Frame
 	if e.Seq == 1 {
@@ -282,7 +282,7 @@ func (p *Poset) checkIfRoot(e *Event) (frame *Frame, isRoot bool) {
 		sSeenCounter := p.members.NewCounter()
 		for member, memberRoots := range p.frames[maxParentsFrame].Roots {
 			for root := range memberRoots {
-				if p.strongly.See(e.Hash(), root) {
+				if p.vi.StronglySee(e.Hash(), root) {
 					sSeenCounter.Count(member)
 				}
 			}