rhp4: add rpc replenish types

.changeset/add_rpcreplenish_to_rhp4.md

@@ -0,0 +1,7 @@
+---
+default: minor
+---
+
+# Add RPCReplenish to RHP4
+
+Adds an RPC to RHP4 that enables renters to set a target balance instead of first fetching the current balance and then funding the account with the difference. This is primarily to speed up account funding and reduce round trips when managing a large number of accounts.

rhp/v4/encoding.go

@@ -593,6 +593,52 @@ func (r *RPCAccountBalanceResponse) maxLen() int {
 	return sizeofCurrency
 }
 
+func (r *RPCReplenishAccountsRequest) encodeTo(e *types.Encoder) {
+	types.EncodeSlice(e, r.Accounts)
+	types.V2Currency(r.Target).EncodeTo(e)
+	r.ContractID.EncodeTo(e)
+	r.ChallengeSignature.EncodeTo(e)
+}
+func (r *RPCReplenishAccountsRequest) decodeFrom(d *types.Decoder) {
+	types.DecodeSlice(d, &r.Accounts)
+	(*types.V2Currency)(&r.Target).DecodeFrom(d)
+	r.ContractID.DecodeFrom(d)
+	r.ChallengeSignature.DecodeFrom(d)
+}
+func (r *RPCReplenishAccountsRequest) maxLen() int {
+	return reasonableObjectSize
+}
+
+func (r *RPCReplenishAccountsResponse) encodeTo(e *types.Encoder) {
+	types.V2Currency(r.Cost).EncodeTo(e)
+}
+func (r *RPCReplenishAccountsResponse) decodeFrom(d *types.Decoder) {
+	(*types.V2Currency)(&r.Cost).DecodeFrom(d)
+}
+func (r *RPCReplenishAccountsResponse) maxLen() int {
+	return sizeofCurrency
+}
+
+func (r *RPCReplenishAccountsSecondResponse) encodeTo(e *types.Encoder) {
+	r.RenterSignature.EncodeTo(e)
+}
+func (r *RPCReplenishAccountsSecondResponse) decodeFrom(d *types.Decoder) {
+	r.RenterSignature.DecodeFrom(d)
+}
+func (r *RPCReplenishAccountsSecondResponse) maxLen() int {
+	return sizeofSignature
+}
+
+func (r *RPCReplenishAccountsThirdResponse) encodeTo(e *types.Encoder) {
+	r.HostSignature.EncodeTo(e)
+}
+func (r *RPCReplenishAccountsThirdResponse) decodeFrom(d *types.Decoder) {
+	r.HostSignature.DecodeFrom(d)
+}
+func (r *RPCReplenishAccountsThirdResponse) maxLen() int {
+	return sizeofSignature
+}
+
 func (r *RPCFundAccountsRequest) encodeTo(e *types.Encoder) {
 	r.ContractID.EncodeTo(e)
 	types.EncodeSlice(e, r.Deposits)

rhp/v4/rhp.go

@@ -31,19 +31,23 @@ const (
 
 // RPC identifiers.
 var (
-	RPCAccountBalanceID  = types.NewSpecifier("AccountBalance")
+	RPCAccountBalanceID    = types.NewSpecifier("AccountBalance")
+	RPCFundAccountsID      = types.NewSpecifier("FundAccounts")
+	RPCReplenishAccountsID = types.NewSpecifier("ReplAccounts")
+
+	RPCAppendSectorsID = types.NewSpecifier("AppendSectors")
+	RPCFreeSectorsID   = types.NewSpecifier("FreeSectors")
+	RPCSectorRootsID   = types.NewSpecifier("SectorRoots")
+
 	RPCFormContractID    = types.NewSpecifier("FormContract")
-	RPCFundAccountsID    = types.NewSpecifier("FundAccounts")
 	RPCLatestRevisionID  = types.NewSpecifier("LatestRevision")
-	RPCAppendSectorsID   = types.NewSpecifier("AppendSectors")
-	RPCFreeSectorsID     = types.NewSpecifier("FreeSectors")
-	RPCReadSectorID      = types.NewSpecifier("ReadSector")
-	RPCRenewContractID   = types.NewSpecifier("RenewContract")
 	RPCRefreshContractID = types.NewSpecifier("RefreshContract")
-	RPCSectorRootsID     = types.NewSpecifier("SectorRoots")
-	RPCSettingsID        = types.NewSpecifier("Settings")
-	RPCWriteSectorID     = types.NewSpecifier("WriteSector")
-	RPCVerifySectorID    = types.NewSpecifier("VerifySector")
+	RPCRenewContractID   = types.NewSpecifier("RenewContract")
+
+	RPCReadSectorID   = types.NewSpecifier("ReadSector")
+	RPCWriteSectorID  = types.NewSpecifier("WriteSector")
+	RPCVerifySectorID = types.NewSpecifier("VerifySector")
+	RPCSettingsID     = types.NewSpecifier("Settings")
 )
 
 func round4KiB(n uint64) uint64 {
@@ -458,6 +462,22 @@ type (
 		Balance types.Currency `json:"balance"`
 	}
 
+	RPCReplenishAccountsRequest struct {
+		Accounts           []Account            `json:"accounts"`
+		Target             types.Currency       `json:"target"`
+		ContractID         types.FileContractID `json:"contractID"`
+		ChallengeSignature types.Signature      `json:"challengeSignature"`
+	}
+	RPCReplenishAccountsResponse struct {
+		Cost types.Currency `json:"cost"`
+	}
+	RPCReplenishAccountsSecondResponse struct {
+		RenterSignature types.Signature `json:"renterSignature"`
+	}
+	RPCReplenishAccountsThirdResponse struct {
+		HostSignature types.Signature `json:"hostSignature"`
+	}
+
 	// RPCVerifySectorRequest implements Object.
 	RPCVerifySectorRequest struct {
 		Prices    HostPrices    `json:"prices"`
@@ -547,6 +567,22 @@ func (r *RPCRefreshContractRequest) ValidChallengeSignature(existing types.V2Fil
 	return existing.RenterPublicKey.VerifyHash(r.ChallengeSigHash(existing.RevisionNumber), r.ChallengeSignature)
 }
 
+// ChallengeSigHash returns the hash of the challenge signature used for
+// signing.
+func (r *RPCReplenishAccountsRequest) ChallengeSigHash(revisionNumber uint64) types.Hash256 {
+	h := types.NewHasher()
+	types.EncodeSlice(h.E, r.Accounts)
+	types.V2Currency(r.Target).EncodeTo(h.E)
+	r.ContractID.EncodeTo(h.E)
+	h.E.WriteUint64(revisionNumber)
+	return h.Sum()
+}
+
+// ValidChallengeSignature checks the challenge signature for validity.
+func (r *RPCReplenishAccountsRequest) ValidChallengeSignature(fc types.V2FileContract) bool {
+	return fc.RenterPublicKey.VerifyHash(r.ChallengeSigHash(fc.RevisionNumber), r.ChallengeSignature)
+}
+
 // NewContract creates a new file contract with the given settings.
 func NewContract(p HostPrices, cp RPCFormContractParams, hostKey types.PublicKey, hostAddress types.Address) (types.V2FileContract, Usage) {
 	return types.V2FileContract{
@@ -656,6 +692,13 @@ func ReviseForFundAccounts(fc types.V2FileContract, amount types.Currency) (type
 	return fc, usage, err
 }
 
+// ReviseForReplenish creates a contract revision for the replenish accounts RPC
+func ReviseForReplenish(fc types.V2FileContract, amount types.Currency) (types.V2FileContract, Usage, error) {
+	usage := Usage{AccountFunding: amount}
+	err := PayWithContract(&fc, usage)
+	return fc, usage, err
+}
+
 // MinRenterAllowance returns the minimum allowance required to justify the given
 // host collateral.
 func MinRenterAllowance(hp HostPrices, duration uint64, collateral types.Currency) types.Currency {

rhp/v4/validation.go

@@ -249,3 +249,16 @@ func (req *RPCAppendSectorsRequest) Validate(pk types.PublicKey) error {
 	}
 	return nil
 }
+
+// Validate checks that the request is valid
+func (req *RPCReplenishAccountsRequest) Validate() error {
+	switch {
+	case len(req.Accounts) == 0:
+		return errors.New("no accounts to replenish")
+	case len(req.Accounts) > 100:
+		return fmt.Errorf("too many accounts to replenish: %d > %d", len(req.Accounts), 1000)
+	case req.Target.IsZero():
+		return errors.New("target must be greater than zero")
+	}
+	return nil
+}