rhp4,chain: simplify renew, move proof updates to chain manager

chain/manager.go

@@ -949,7 +949,7 @@ func (m *Manager) V2TransactionSet(basis types.ChainIndex, txn types.V2Transacti
 	m.revalidatePool()
 
 	// update the transaction's basis to match tip
-	_, txns, err := m.updateV2TransactionSet(basis, []types.V2Transaction{txn})
+	txns, err := m.UpdateV2TransactionSet([]types.V2Transaction{txn}, basis, m.tipState.Index)
 	if err != nil {
 		return types.ChainIndex{}, nil, fmt.Errorf("failed to update transaction set basis: %w", err)
 	} else if len(txns) == 0 {
@@ -1086,47 +1086,86 @@ func (m *Manager) AddPoolTransactions(txns []types.Transaction) (known bool, err
 	return
 }
 
-// updateV2TransactionSet updates the basis of a transaction set to the current
-// tip. If the basis is already the tip, the transaction set is returned as-is.
-// Any transactions that were confirmed are removed from the set. Any ephemeral
-// state elements that were created by an update are updated.
+// UpdateStateElement updates the basis of a state element from "from" to "to".
+// If from and to are equal, the state element is not modified.
+func (m *Manager) UpdateStateElement(se *types.StateElement, from, to types.ChainIndex) error {
+	if from == to {
+		return nil
+	}
+
+	revert, apply, err := m.reorgPath(from, to)
+	if err != nil {
+		return fmt.Errorf("couldn't determine reorg path from %v to %v: %w", from, to, err)
+	} else if len(revert)+len(apply) > 144 {
+		return fmt.Errorf("reorg path from %v to %v is too long (-%v +%v)", from, to, len(revert), len(apply))
+	}
+	for _, index := range revert {
+		b, _, cs, ok := blockAndParent(m.store, index.ID)
+		if !ok {
+			return fmt.Errorf("missing reverted block at index %v", index)
+		} else if b.V2 == nil {
+			return fmt.Errorf("reorg path from %v to %v contains a non-v2 block (%v)", from, to, index)
+		}
+		// NOTE: since we are post-hardfork, we don't need a v1 supplement
+		cru := consensus.RevertBlock(cs, b, consensus.V1BlockSupplement{})
+		cru.UpdateElementProof(se)
+	}
+
+	for _, index := range apply {
+		b, _, cs, ok := blockAndParent(m.store, index.ID)
+		if !ok {
+			return fmt.Errorf("missing applied block at index %v", index)
+		} else if b.V2 == nil {
+			return fmt.Errorf("reorg path from %v to %v contains a non-v2 block (%v)", from, to, index)
+		}
+		// NOTE: since we are post-hardfork, we don't need a v1 supplement or ancestorTimestamp
+		_, cau := consensus.ApplyBlock(cs, b, consensus.V1BlockSupplement{}, time.Time{})
+		cau.UpdateElementProof(se)
+	}
+	return nil
+}
+
+// UpdateV2TransactionSet updates the basis of a transaction set from "from" to "to".
+// If from and to are equal, the transaction set is returned as-is.
+// Any transactions that were confirmed are removed from the set.
+// Any ephemeral state elements that were created by an update are updated.
 //
 // If it is undesirable to modify the transaction set, deep-copy it
 // before calling this method.
-func (m *Manager) updateV2TransactionSet(basis types.ChainIndex, txns []types.V2Transaction) (types.ChainIndex, []types.V2Transaction, error) {
-	if basis == m.tipState.Index {
-		return basis, txns, nil
+func (m *Manager) UpdateV2TransactionSet(txns []types.V2Transaction, from, to types.ChainIndex) ([]types.V2Transaction, error) {
+	if from == to {
+		return txns, nil
 	}
 
 	// bring txns up-to-date
-	revert, apply, err := m.reorgPath(basis, m.tipState.Index)
+	revert, apply, err := m.reorgPath(from, to)
 	if err != nil {
-		return types.ChainIndex{}, nil, fmt.Errorf("couldn't determine reorg path from %v to %v: %w", basis, m.tipState.Index, err)
+		return nil, fmt.Errorf("couldn't determine reorg path from %v to %v: %w", from, to, err)
 	} else if len(revert)+len(apply) > 144 {
-		return types.ChainIndex{}, nil, fmt.Errorf("reorg path from %v to %v is too long (-%v +%v)", basis, m.tipState.Index, len(revert), len(apply))
+		return nil, fmt.Errorf("reorg path from %v to %v is too long (-%v +%v)", from, to, len(revert), len(apply))
 	}
 	for _, index := range revert {
 		b, _, cs, ok := blockAndParent(m.store, index.ID)
 		if !ok {
-			return types.ChainIndex{}, nil, fmt.Errorf("missing reverted block at index %v", index)
+			return nil, fmt.Errorf("missing reverted block at index %v", index)
 		} else if b.V2 == nil {
-			return types.ChainIndex{}, nil, fmt.Errorf("reorg path from %v to %v contains a non-v2 block (%v)", basis, m.tipState.Index, index)
+			return nil, fmt.Errorf("reorg path from %v to %v contains a non-v2 block (%v)", from, to, index)
 		}
 		// NOTE: since we are post-hardfork, we don't need a v1 supplement
 		cru := consensus.RevertBlock(cs, b, consensus.V1BlockSupplement{})
 		for i := range txns {
 			if !updateTxnProofs(&txns[i], cru.UpdateElementProof, cs.Elements.NumLeaves) {
-				return types.ChainIndex{}, nil, fmt.Errorf("transaction %v references element that does not exist in our chain", txns[i].ID())
+				return nil, fmt.Errorf("transaction %v references element that does not exist in our chain", txns[i].ID())
 			}
 		}
 	}
 
 	for _, index := range apply {
 		b, _, cs, ok := blockAndParent(m.store, index.ID)
 		if !ok {
-			return types.ChainIndex{}, nil, fmt.Errorf("missing applied block at index %v", index)
+			return nil, fmt.Errorf("missing applied block at index %v", index)
 		} else if b.V2 == nil {
-			return types.ChainIndex{}, nil, fmt.Errorf("reorg path from %v to %v contains a non-v2 block (%v)", basis, m.tipState.Index, index)
+			return nil, fmt.Errorf("reorg path from %v to %v contains a non-v2 block (%v)", from, to, index)
 		}
 		// NOTE: since we are post-hardfork, we don't need a v1 supplement or ancestorTimestamp
 		cs, cau := consensus.ApplyBlock(cs, b, consensus.V1BlockSupplement{}, time.Time{})
@@ -1154,7 +1193,6 @@ func (m *Manager) updateV2TransactionSet(basis types.ChainIndex, txns []types.V2
 				// remove any transactions that were confirmed in this block
 				continue
 			}
-			rem = append(rem, txns[i])
 
 			// update the state elements for any confirmed ephemeral elements
 			for j := range txns[i].SiacoinInputs {
@@ -1182,11 +1220,12 @@ func (m *Manager) updateV2TransactionSet(basis types.ChainIndex, txns []types.V2
 
 			// NOTE: all elements guaranteed to exist from here on, so no
 			// need to check this return value
-			updateTxnProofs(&rem[len(rem)-1], cau.UpdateElementProof, cs.Elements.NumLeaves)
+			updateTxnProofs(&txns[i], cau.UpdateElementProof, cs.Elements.NumLeaves)
+			rem = append(rem, txns[i])
 		}
 		txns = rem
 	}
-	return m.tipState.Index, txns, nil
+	return txns, nil
 }
 
 // AddV2PoolTransactions validates a transaction set and adds it to the txpool.
@@ -1220,7 +1259,7 @@ func (m *Manager) AddV2PoolTransactions(basis types.ChainIndex, txns []types.V2T
 	}
 
 	// update the transaction set to the current tip
-	_, txns, err := m.updateV2TransactionSet(basis, txns)
+	txns, err := m.UpdateV2TransactionSet(txns, basis, m.tipState.Index)
 	if err != nil {
 		return false, m.markBadTxnSet(setID, fmt.Errorf("failed to update set basis: %w", err))
 	} else if len(txns) == 0 {

go.mod

@@ -4,7 +4,7 @@ go 1.23.0
 
 require (
 	go.etcd.io/bbolt v1.3.11
-	go.sia.tech/core v0.4.8-0.20241002233523-418236837b5a
+	go.sia.tech/core v0.4.8-0.20241003192046-425f95763c90
 	go.sia.tech/mux v1.3.0
 	go.uber.org/zap v1.27.0
 	golang.org/x/crypto v0.27.0

go.sum

@@ -8,8 +8,8 @@ github.com/stretchr/testify v1.8.1 h1:w7B6lhMri9wdJUVmEZPGGhZzrYTPvgJArz7wNPgYKs
 github.com/stretchr/testify v1.8.1/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4=
 go.etcd.io/bbolt v1.3.11 h1:yGEzV1wPz2yVCLsD8ZAiGHhHVlczyC9d1rP43/VCRJ0=
 go.etcd.io/bbolt v1.3.11/go.mod h1:dksAq7YMXoljX0xu6VF5DMZGbhYYoLUalEiSySYAS4I=
-go.sia.tech/core v0.4.8-0.20241002233523-418236837b5a h1:Lz7h42eZCk8iI4/agdWNwlVneqaybxkV1lor+Eavzso=
-go.sia.tech/core v0.4.8-0.20241002233523-418236837b5a/go.mod h1:j2Ke8ihV8or7d2VDrFZWcCkwSVHO0DNMQJAGs9Qop2M=
+go.sia.tech/core v0.4.8-0.20241003192046-425f95763c90 h1:R/G7XXyzLKelfGBGT6XQpih379v5jJx6T4AsjLwyjJc=
+go.sia.tech/core v0.4.8-0.20241003192046-425f95763c90/go.mod h1:j2Ke8ihV8or7d2VDrFZWcCkwSVHO0DNMQJAGs9Qop2M=
 go.sia.tech/mux v1.3.0 h1:hgR34IEkqvfBKUJkAzGi31OADeW2y7D6Bmy/Jcbop9c=
 go.sia.tech/mux v1.3.0/go.mod h1:I46++RD4beqA3cW9Xm9SwXbezwPqLvHhVs9HLpDtt58=
 go.uber.org/goleak v1.3.0 h1:2K3zAYmnTNqV73imy9J1T3WC+gmCePx2hEGkimedGto=

rhp/v4/rpc.go

@@ -649,48 +649,28 @@ func RPCRenewContract(ctx context.Context, t TransportClient, tp TxPool, signer
 	}
 
 	renterCost, hostCost := rhp4.RenewalCost(cs, p, renewal, renewalTxn.MinerFee)
-
-	basis := cs.Index // start with a decent basis and overwrite it if a setup transaction is needed
-	var renewalParents []types.V2Transaction
-	if !renterCost.IsZero() {
-		setupTxn := types.V2Transaction{
-			SiacoinOutputs: []types.SiacoinOutput{
-				{Address: renewal.NewContract.RenterOutput.Address, Value: renterCost},
-			},
-		}
-		var err error
-		var toSign []int
-		basis, toSign, err = signer.FundV2Transaction(&setupTxn, renterCost)
-		if err != nil {
-			return RPCRenewContractResult{}, fmt.Errorf("failed to fund transaction: %w", err)
-		}
-		signer.SignV2Inputs(&setupTxn, toSign)
-
-		basis, renewalParents, err = tp.V2TransactionSet(basis, setupTxn)
-		if err != nil {
-			return RPCRenewContractResult{}, fmt.Errorf("failed to get transaction set: %w", err)
-		}
-		setupTxn = renewalParents[len(renewalParents)-1]
-
-		renewalTxn.SiacoinInputs = append(renewalTxn.SiacoinInputs, types.V2SiacoinInput{
-			Parent: setupTxn.EphemeralSiacoinOutput(0),
-		})
-		signer.SignV2Inputs(&renewalTxn, []int{0})
+	req := rhp4.RPCRenewContractRequest{
+		Prices:   p,
+		Renewal:  params,
+		MinerFee: renewalTxn.MinerFee,
+		Basis:    cs.Index,
 	}
 
-	renterSiacoinElements := make([]types.SiacoinElement, 0, len(renewalTxn.SiacoinInputs))
-	for _, i := range renewalTxn.SiacoinInputs {
-		renterSiacoinElements = append(renterSiacoinElements, i.Parent)
+	basis, toSign, err := signer.FundV2Transaction(&renewalTxn, renterCost)
+	if err != nil {
+		return RPCRenewContractResult{}, fmt.Errorf("failed to fund transaction: %w", err)
 	}
+	signer.SignV2Inputs(&renewalTxn, toSign)
 
-	req := rhp4.RPCRenewContractRequest{
-		Prices:        p,
-		Renewal:       params,
-		MinerFee:      renewalTxn.MinerFee,
-		Basis:         basis,
-		RenterInputs:  renterSiacoinElements,
-		RenterParents: renewalParents,
+	req.Basis, req.RenterParents, err = tp.V2TransactionSet(basis, renewalTxn)
+	if err != nil {
+		return RPCRenewContractResult{}, fmt.Errorf("failed to get transaction set: %w", err)
 	}
+	for _, si := range renewalTxn.SiacoinInputs {
+		req.RenterInputs = append(req.RenterInputs, si.Parent)
+	}
+	req.RenterParents = req.RenterParents[:len(req.RenterParents)-1] // last transaction is the renewal
+
 	sigHash := req.ChallengeSigHash(existing.RevisionNumber)
 	req.ChallengeSignature = signer.SignHash(sigHash)
 
@@ -714,8 +694,14 @@ func RPCRenewContract(ctx context.Context, t TransportClient, tp TxPool, signer
 	}
 
 	// verify the host added enough inputs
-	if !hostInputSum.Equals(hostCost) {
+	if n := hostInputSum.Cmp(hostCost); n < 0 {
 		return RPCRenewContractResult{}, fmt.Errorf("expected host to fund %v, got %v", hostCost, hostInputSum)
+	} else if n > 0 {
+		// add change output
+		renewalTxn.SiacoinOutputs = append(renewalTxn.SiacoinOutputs, types.SiacoinOutput{
+			Address: existing.HostOutput.Address,
+			Value:   hostInputSum.Sub(hostCost),
+		})
 	}
 
 	// sign the renter inputs
@@ -728,7 +714,7 @@ func RPCRenewContract(ctx context.Context, t TransportClient, tp TxPool, signer
 	renterPolicyResp := rhp4.RPCRenewContractSecondResponse{
 		RenterRenewalSignature: renewal.RenterSignature,
 	}
-	for _, si := range renewalTxn.SiacoinInputs[:len(renterSiacoinElements)] {
+	for _, si := range renewalTxn.SiacoinInputs[:len(req.RenterInputs)] {
 		renterPolicyResp.RenterSatisfiedPolicies = append(renterPolicyResp.RenterSatisfiedPolicies, si.SatisfiedPolicy)
 	}
 	if err := rhp4.WriteResponse(s, &renterPolicyResp); err != nil {