Implement RPCReplenishAccounts

.changeset/add_rpcreplenishaccounts_implementation.md

@@ -0,0 +1,7 @@
+---
+default: minor
+---
+
+# Add RPCReplenishAccounts Implementation
+
+Implements RPCReplenishAccounts in the RHP4 client and server enabling clients managing a large number of accounts to fund them quicker

go.mod

@@ -8,7 +8,7 @@ require (
 	github.com/quic-go/quic-go v0.49.0
 	github.com/quic-go/webtransport-go v0.8.1-0.20241018022711-4ac2c9250e66
 	go.etcd.io/bbolt v1.4.0
-	go.sia.tech/core v0.10.1
+	go.sia.tech/core v0.10.2-0.20250219233743-df244d4e3f99
 	go.sia.tech/mux v1.3.0
 	go.uber.org/zap v1.27.0
 	golang.org/x/crypto v0.33.0

go.sum

@@ -31,8 +31,8 @@ github.com/stretchr/testify v1.10.0 h1:Xv5erBjTwe/5IxqUQTdXv5kgmIvbHo3QQyRwhJsOf
 github.com/stretchr/testify v1.10.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
 go.etcd.io/bbolt v1.4.0 h1:TU77id3TnN/zKr7CO/uk+fBCwF2jGcMuw2B/FMAzYIk=
 go.etcd.io/bbolt v1.4.0/go.mod h1:AsD+OCi/qPN1giOX1aiLAha3o1U8rAz65bvN4j0sRuk=
-go.sia.tech/core v0.10.1 h1:96lmgO50oKPiQU46H14Ga+6NYo6IB++VQ4DI3QCc6/o=
-go.sia.tech/core v0.10.1/go.mod h1:FRg3rOIM8oSvf5wJoAJEgqqbTtKBDNeqL5/bH1lRuDk=
+go.sia.tech/core v0.10.2-0.20250219233743-df244d4e3f99 h1:5/VLOh4rxfsOKxk+rV22eAMj+PJuf/EMtURa1UwbZrU=
+go.sia.tech/core v0.10.2-0.20250219233743-df244d4e3f99/go.mod h1:FRg3rOIM8oSvf5wJoAJEgqqbTtKBDNeqL5/bH1lRuDk=
 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

@@ -145,6 +145,20 @@ type (
 		Usage    rhp4.Usage           `json:"usage"`
 	}
 
+	// RPCReplenishAccountsParams contains the parameters for the replenish accounts RPC.
+	RPCReplenishAccountsParams struct {
+		Accounts []rhp4.Account   `json:"accounts"`
+		Target   types.Currency   `json:"target"`
+		Contract ContractRevision `json:"contract"`
+	}
+
+	// RPCReplenishAccountsResult contains the result of executing the replenish accounts RPC.
+	RPCReplenishAccountsResult struct {
+		Revision types.V2FileContract  `json:"revision"`
+		Deposits []rhp4.AccountDeposit `json:"deposits"`
+		Usage    rhp4.Usage            `json:"usage"`
+	}
+
 	// RPCSectorRootsResult contains the result of executing the sector roots RPC.
 	RPCSectorRootsResult struct {
 		Revision types.V2FileContract `json:"revision"`
@@ -366,6 +380,7 @@ func RPCFreeSectors(ctx context.Context, t TransportClient, cs consensus.State,
 	if err := rhp4.ReadResponse(s, &hostSignature); err != nil {
 		return RPCFreeSectorsResult{}, fmt.Errorf("failed to read host signatures: %w", err)
 	}
+	revision.HostSignature = hostSignature.HostSignature
 	// validate the host signature
 	if !contract.Revision.HostPublicKey.VerifyHash(sigHash, hostSignature.HostSignature) {
 		return RPCFreeSectorsResult{}, rhp4.ErrInvalidSignature
@@ -488,6 +503,83 @@ func RPCFundAccounts(ctx context.Context, t TransportClient, cs consensus.State,
 	}, nil
 }
 
+// RPCReplenishAccounts replenishes accounts on the host.
+func RPCReplenishAccounts(ctx context.Context, t TransportClient, p RPCReplenishAccountsParams, cs consensus.State, signer ContractSigner) (RPCReplenishAccountsResult, error) {
+	req := rhp4.RPCReplenishAccountsRequest{
+		Accounts:   p.Accounts,
+		Target:     p.Target,
+		ContractID: p.Contract.ID,
+	}
+	challengeSigHash := req.ChallengeSigHash(p.Contract.Revision.RevisionNumber)
+	req.ChallengeSignature = signer.SignHash(challengeSigHash)
+
+	if err := req.Validate(); err != nil {
+		return RPCReplenishAccountsResult{}, fmt.Errorf("invalid request: %w", err)
+	}
+
+	s, err := t.DialStream()
+	if err != nil {
+		return RPCReplenishAccountsResult{}, fmt.Errorf("failed to dial stream: %w", err)
+	}
+	defer s.Close()
+
+	if err := rhp4.WriteRequest(s, rhp4.RPCReplenishAccountsID, &req); err != nil {
+		return RPCReplenishAccountsResult{}, fmt.Errorf("failed to write request: %w", err)
+	}
+
+	maxCost := p.Target.Mul64(uint64(len(p.Accounts)))
+
+	var resp rhp4.RPCReplenishAccountsResponse
+	if err := rhp4.ReadResponse(s, &resp); err != nil {
+		return RPCReplenishAccountsResult{}, fmt.Errorf("failed to read response: %w", err)
+	}
+
+	for _, deposit := range resp.Deposits {
+		if deposit.Amount.Cmp(p.Target) > 0 {
+			return RPCReplenishAccountsResult{}, fmt.Errorf("expected deposit <= %v, got %v", p.Target, deposit.Amount)
+		}
+	}
+
+	totalCost := resp.TotalCost()
+	if totalCost.IsZero() {
+		// return early with the current revision if no deposits are needed
+		return RPCReplenishAccountsResult{
+			Revision: p.Contract.Revision,
+			Deposits: resp.Deposits,
+		}, nil
+	} else if totalCost.Cmp(maxCost) > 0 {
+		return RPCReplenishAccountsResult{}, fmt.Errorf("expected cost <= %v, got %v", maxCost, totalCost)
+	}
+
+	revision, usage, err := rhp4.ReviseForReplenish(p.Contract.Revision, totalCost)
+	if err != nil {
+		return RPCReplenishAccountsResult{}, fmt.Errorf("failed to revise contract: %w", err)
+	}
+
+	sigHash := cs.ContractSigHash(revision)
+	revision.RenterSignature = signer.SignHash(sigHash)
+
+	signatureResp := rhp4.RPCReplenishAccountsSecondResponse{
+		RenterSignature: revision.RenterSignature,
+	}
+	if err := rhp4.WriteResponse(s, &signatureResp); err != nil {
+		return RPCReplenishAccountsResult{}, fmt.Errorf("failed to write signature response: %w", err)
+	}
+
+	var hostSignature rhp4.RPCReplenishAccountsThirdResponse
+	if err := rhp4.ReadResponse(s, &hostSignature); err != nil {
+		return RPCReplenishAccountsResult{}, fmt.Errorf("failed to read host signatures: %w", err)
+	} else if !p.Contract.Revision.HostPublicKey.VerifyHash(sigHash, hostSignature.HostSignature) {
+		return RPCReplenishAccountsResult{}, fmt.Errorf("failed to validate host signature: %w", rhp4.ErrInvalidSignature)
+	}
+	revision.HostSignature = hostSignature.HostSignature
+	return RPCReplenishAccountsResult{
+		Revision: revision,
+		Deposits: resp.Deposits,
+		Usage:    usage,
+	}, nil
+}
+
 // RPCLatestRevision returns the latest revision of a contract.
 func RPCLatestRevision(ctx context.Context, t TransportClient, contractID types.FileContractID) (resp rhp4.RPCLatestRevisionResponse, err error) {
 	req := rhp4.RPCLatestRevisionRequest{ContractID: contractID}