From 156a14eeeb2ae4ede1c16e6655601d0af6a84060 Mon Sep 17 00:00:00 2001
From: Jakub Sztandera <kubuxu@protocol.ai>
Date: Tue, 23 Jun 2020 16:59:44 +0200
Subject: [PATCH] Integrate Poisson Sortition into chain sync

Signed-off-by: Jakub Sztandera <kubuxu@protocol.ai>
---
 chain/gen/gen.go      |  8 ++++++--
 chain/store/weight.go | 20 ++++++++++++++------
 chain/sub/incoming.go |  6 ++++++
 chain/sync.go         | 10 +++++++---
 4 files changed, 33 insertions(+), 11 deletions(-)

diff --git a/chain/gen/gen.go b/chain/gen/gen.go
index 89d4f32bf..14581ded9 100644
--- a/chain/gen/gen.go
+++ b/chain/gen/gen.go
@@ -559,11 +559,15 @@ func IsRoundWinner(ctx context.Context, ts *types.TipSet, round abi.ChainEpoch,
 	}
 
 	// TODO: wire in real power
-	if !types.IsTicketWinner(vrfout, mbi.MinerPower, mbi.NetworkPower) {
+	// TODO: is above TODO still applicable?
+	ep := &types.ElectionProof{VRFProof: vrfout}
+	j := ep.ComputeWinCount(mbi.MinerPower, mbi.NetworkPower)
+	ep.WinCount = j
+	if j < 1 {
 		return nil, nil
 	}
 
-	return &types.ElectionProof{VRFProof: vrfout}, nil
+	return ep, nil
 }
 
 type SignFunc func(context.Context, address.Address, []byte) (*crypto.Signature, error)
diff --git a/chain/store/weight.go b/chain/store/weight.go
index c92f1a74d..ac51aeb45 100644
--- a/chain/store/weight.go
+++ b/chain/store/weight.go
@@ -21,11 +21,11 @@ func (cs *ChainStore) Weight(ctx context.Context, ts *types.TipSet) (types.BigIn
 	if ts == nil {
 		return types.NewInt(0), nil
 	}
-	// >>> w[r] <<< + wFunction(totalPowerAtTipset(ts)) * 2^8 + (wFunction(totalPowerAtTipset(ts)) * len(ts.blocks) * wRatio_num * 2^8) / (e * wRatio_den)
+	// >>> w[r] <<< + wFunction(totalPowerAtTipset(ts)) * 2^8 + (wFunction(totalPowerAtTipset(ts)) * sum(ts.blocks.ElectionProof.WinCount) * wRatio_num * 2^8) / (e * wRatio_den)
 
 	var out = new(big.Int).Set(ts.Blocks()[0].ParentWeight.Int)
 
-	// >>> wFunction(totalPowerAtTipset(ts)) * 2^8 <<< + (wFunction(totalPowerAtTipset(ts)) * len(ts.blocks) * wRatio_num * 2^8) / (e * wRatio_den)
+	// >>> wFunction(totalPowerAtTipset(ts)) * 2^8 <<< + (wFunction(totalPowerAtTipset(ts)) * sum(ts.blocks.ElectionProof.WinCount) * wRatio_num * 2^8) / (e * wRatio_den)
 
 	tpow := big2.Zero()
 	{
@@ -57,11 +57,19 @@ func (cs *ChainStore) Weight(ctx context.Context, ts *types.TipSet) (types.BigIn
 
 	out.Add(out, big.NewInt(log2P<<8))
 
-	// (wFunction(totalPowerAtTipset(ts)) * len(ts.blocks) * wRatio_num * 2^8) / (e * wRatio_den)
+	// (wFunction(totalPowerAtTipset(ts)) * sum(ts.blocks.ElectionProof.WinCount) * wRatio_num * 2^8) / (e * wRatio_den)
 
-	eWeight := big.NewInt((log2P * int64(len(ts.Blocks())) * build.WRatioNum) << 8)
-	eWeight.Div(eWeight, big.NewInt(int64(build.BlocksPerEpoch*build.WRatioDen)))
-	out.Add(out, eWeight)
+	totalJ := uint64(0)
+	for _, b := range ts.Blocks() {
+		totalJ += b.ElectionProof.WinCount
+	}
+
+	eWeight := big.NewInt((log2P * build.WRatioNum))
+	eWeight = eWeight.Lsh(eWeight, 8)
+	eWeight = eWeight.Mul(eWeight, new(big.Int).SetUint64(totalJ))
+	eWeight = eWeight.Div(eWeight, big.NewInt(int64(build.BlocksPerEpoch*build.WRatioDen)))
+
+	out = out.Add(out, eWeight)
 
 	return types.BigInt{Int: out}, nil
 }
diff --git a/chain/sub/incoming.go b/chain/sub/incoming.go
index ba61dc5c5..0c4350d03 100644
--- a/chain/sub/incoming.go
+++ b/chain/sub/incoming.go
@@ -210,6 +210,12 @@ func (bv *BlockValidator) Validate(ctx context.Context, pid peer.ID, msg *pubsub
 		return pubsub.ValidationReject
 	}
 
+	if blk.Header.ElectionProof.WinCount < 1 {
+		log.Errorf("block is not claiming to be winning")
+		recordFailure("not_winning")
+		return pubsub.ValidationReject
+	}
+
 	// it's a good block! make sure we've only seen it once
 	if bv.recvBlocks.add(blk.Header.Cid()) > 0 {
 		// TODO: once these changes propagate to the network, we can consider
diff --git a/chain/sync.go b/chain/sync.go
index 26f30d95b..b190dc449 100644
--- a/chain/sync.go
+++ b/chain/sync.go
@@ -651,6 +651,10 @@ func (syncer *Syncer) ValidateBlock(ctx context.Context, b *types.FullBlock) (er
 	}
 
 	winnerCheck := async.Err(func() error {
+		if h.ElectionProof.WinCount < 1 {
+			return xerrors.Errorf("block is not claiming to be a winner")
+		}
+
 		rBeacon := *prevBeacon
 		if len(h.BeaconEntries) != 0 {
 			rBeacon = h.BeaconEntries[len(h.BeaconEntries)-1]
@@ -660,7 +664,6 @@ func (syncer *Syncer) ValidateBlock(ctx context.Context, b *types.FullBlock) (er
 			return xerrors.Errorf("failed to marshal miner address to cbor: %w", err)
 		}
 
-		//TODO: DST from spec actors when it is there
 		vrfBase, err := store.DrawRandomness(rBeacon.Data, crypto.DomainSeparationTag_ElectionProofProduction, h.Height, buf.Bytes())
 		if err != nil {
 			return xerrors.Errorf("could not draw randomness: %w", err)
@@ -684,8 +687,9 @@ func (syncer *Syncer) ValidateBlock(ctx context.Context, b *types.FullBlock) (er
 			return xerrors.Errorf("failed getting power: %w", err)
 		}
 
-		if !types.IsTicketWinner(h.ElectionProof.VRFProof, mpow.QualityAdjPower, tpow.QualityAdjPower) {
-			return xerrors.Errorf("miner created a block but was not a winner")
+		j := h.ElectionProof.ComputeWinCount(mpow.QualityAdjPower, tpow.QualityAdjPower)
+		if h.ElectionProof.WinCount != j {
+			return xerrors.Errorf("miner claims wrong number of wins: miner: %d, computed: %d", h.ElectionProof.WinCount, j)
 		}
 
 		return nil