Merge pull request OffchainLabs#2483 from OffchainLabs/batch-confirma…

…tions-on-migration

Batch validator confirmations when nitro migration begins

packages/arb-node-core/ethbridge/rollupWatcher.go

@@ -243,6 +243,19 @@ func (r *RollupWatcher) LookupChallengedNode(ctx context.Context, address common
 	return challenge.ChallengedNode, nil
 }
 
+func (r *RollupWatcher) GetNodeStakerCount(ctx context.Context, nodeNum *big.Int) (*big.Int, error) {
+	callOpts := r.getCallOpts(ctx)
+	nodeAddr, err := r.con.GetNode(callOpts, nodeNum)
+	if err != nil {
+		return nil, err
+	}
+	nodeContract, err := ethbridgecontracts.NewINode(nodeAddr, r.client)
+	if err != nil {
+		return nil, err
+	}
+	return nodeContract.StakerCount(callOpts)
+}
+
 func (r *RollupWatcher) StakerInfo(ctx context.Context, staker common.Address) (*StakerInfo, error) {
 	info, err := r.con.StakerMap(r.getCallOpts(ctx), staker.ToEthAddress())
 	if err != nil {
@@ -330,3 +343,12 @@ func (r *RollupWatcher) GetNode(ctx context.Context, node core.NodeID) (*NodeWat
 	}
 	return NewNodeWatcher(nodeAddress, r.client, r.baseCallOpts)
 }
+
+func (r *RollupWatcher) IsShuttingDownForNitro(ctx context.Context) (bool, error) {
+	shuttingDownForNitro, err := r.con.ShutdownForNitroMode(r.getCallOpts(ctx))
+	if err != nil {
+		logger.Warn().Err(err).Msg("assuming not shutting down for nitro as we failed to check")
+		return false, nil
+	}
+	return shuttingDownForNitro, nil
+}

packages/arb-node-core/staker/validator.go

@@ -136,6 +136,14 @@ func (v *Validator) resolveNextNode(ctx context.Context, info *ethbridge.StakerI
 	if err != nil {
 		return err
 	}
+	latestNodeCreated, err := v.rollup.LatestNodeCreated(ctx)
+	if err != nil {
+		return err
+	}
+	shuttingDownForNitro, err := v.rollup.IsShuttingDownForNitro(ctx)
+	if err != nil {
+		return err
+	}
 	switch confirmType {
 	case ethbridge.CONFIRM_TYPE_INVALID:
 		addr := v.wallet.Address()
@@ -146,17 +154,52 @@ func (v *Validator) resolveNextNode(ctx context.Context, info *ethbridge.StakerI
 		logger.Info().Int("node", int(unresolvedNodeIndex.Int64())).Msg("Rejecting node")
 		return v.rollup.RejectNextNode(ctx, *addr)
 	case ethbridge.CONFIRM_TYPE_VALID:
-		nodeInfo, err := v.rollup.RollupWatcher.LookupNode(ctx, unresolvedNodeIndex)
-		if err != nil {
-			return err
+		confCount := 1
+		if shuttingDownForNitro {
+			confCount = 10
 		}
-		sendCount := new(big.Int).Sub(nodeInfo.Assertion.After.TotalSendCount, nodeInfo.Assertion.Before.TotalSendCount)
-		sends, err := v.lookup.GetSends(nodeInfo.Assertion.Before.TotalSendCount, sendCount)
-		if err != nil {
-			return errors.Wrap(err, "catching up to chain")
+		totalSendSize := 0
+		var lastStakerCount *big.Int
+		for i := 0; i < confCount && unresolvedNodeIndex.Cmp(latestNodeCreated) <= 0; i++ {
+			nodeInfo, err := v.rollup.RollupWatcher.LookupNode(ctx, unresolvedNodeIndex)
+			if err != nil {
+				return err
+			}
+			stakerCount, err := v.rollup.RollupWatcher.GetNodeStakerCount(ctx, unresolvedNodeIndex)
+			if err != nil {
+				return err
+			}
+			if lastStakerCount != nil {
+				if lastStakerCount.Cmp(stakerCount) != 0 {
+					logger.
+						Info().
+						Int64("stakerCount", stakerCount.Int64()).
+						Int64("lastStakerCount", lastStakerCount.Int64()).
+						Msg("not batching further confirmations as number of stakers changed")
+					break
+				}
+			} else {
+				lastStakerCount = stakerCount
+			}
+			sendCount := new(big.Int).Sub(nodeInfo.Assertion.After.TotalSendCount, nodeInfo.Assertion.Before.TotalSendCount)
+			sends, err := v.lookup.GetSends(nodeInfo.Assertion.Before.TotalSendCount, sendCount)
+			if err != nil {
+				return errors.Wrap(err, "catching up to chain")
+			}
+			for _, send := range sends {
+				totalSendSize += 32 + len(send)
+			}
+			if i > 0 && totalSendSize >= 64*1024 {
+				break
+			}
+			logger.Info().Int("node", int(unresolvedNodeIndex.Int64())).Msg("Confirming node")
+			err = v.rollup.ConfirmNextNode(ctx, nodeInfo.Assertion, sends)
+			if err != nil {
+				return err
+			}
+			unresolvedNodeIndex.Add(unresolvedNodeIndex, big.NewInt(1))
 		}
-		logger.Info().Int("node", int(unresolvedNodeIndex.Int64())).Msg("Confirming node")
-		return v.rollup.ConfirmNextNode(ctx, nodeInfo.Assertion, sends)
+		return nil
 	default:
 		return nil
 	}