// FundSiafunds will add a siafund input of exaclty 'amount' to the
// transaction. A parent transaction may be needed to achieve an input with the
// correct value. The siafund input will not be signed until 'Sign' is called
// on the transaction builder.
func (tb *transactionBuilder) FundSiafunds(amount types.Currency) error {
tb.wallet.mu.Lock()
defer tb.wallet.mu.Unlock()
// Create and fund a parent transaction that will add the correct amount of
// siafunds to the transaction.
var fund types.Currency
var potentialFund types.Currency
parentTxn := types.Transaction{}
var spentSfoids []types.SiafundOutputID
for sfoid, sfo := range tb.wallet.siafundOutputs {
// Check that this output has not recently been spent by the wallet.
spendHeight := tb.wallet.spentOutputs[types.OutputID(sfoid)]
// Prevent an underflow error.
allowedHeight := tb.wallet.consensusSetHeight - RespendTimeout
if tb.wallet.consensusSetHeight < RespendTimeout {
allowedHeight = 0
}
if spendHeight > allowedHeight {
potentialFund = potentialFund.Add(sfo.Value)
continue
}
outputUnlockConditions := tb.wallet.keys[sfo.UnlockHash].UnlockConditions
if tb.wallet.consensusSetHeight < outputUnlockConditions.Timelock {
continue
}
// Add a siafund input for this output.
parentClaimUnlockConditions, err := tb.wallet.nextPrimarySeedAddress()
if err != nil {
return err
}
sfi := types.SiafundInput{
ParentID: sfoid,
UnlockConditions: outputUnlockConditions,
ClaimUnlockHash: parentClaimUnlockConditions.UnlockHash(),
}
parentTxn.SiafundInputs = append(parentTxn.SiafundInputs, sfi)
spentSfoids = append(spentSfoids, sfoid)
// Add the output to the total fund
fund = fund.Add(sfo.Value)
potentialFund = potentialFund.Add(sfo.Value)
if fund.Cmp(amount) >= 0 {
break
}
}
if potentialFund.Cmp(amount) >= 0 && fund.Cmp(amount) < 0 {
return modules.ErrPotentialDoubleSpend
}
if fund.Cmp(amount) < 0 {
return modules.ErrLowBalance
}
// Create and add the output that will be used to fund the standard
// transaction.
parentUnlockConditions, err := tb.wallet.nextPrimarySeedAddress()
if err != nil {
return err
}
exactOutput := types.SiafundOutput{
Value: amount,
UnlockHash: parentUnlockConditions.UnlockHash(),
}
parentTxn.SiafundOutputs = append(parentTxn.SiafundOutputs, exactOutput)
// Create a refund output if needed.
if amount.Cmp(fund) != 0 {
refundUnlockConditions, err := tb.wallet.nextPrimarySeedAddress()
if err != nil {
return err
}
refundOutput := types.SiafundOutput{
Value: fund.Sub(amount),
UnlockHash: refundUnlockConditions.UnlockHash(),
}
parentTxn.SiafundOutputs = append(parentTxn.SiafundOutputs, refundOutput)
}
// Sign all of the inputs to the parent trancstion.
for _, sfi := range parentTxn.SiafundInputs {
_, err := addSignatures(&parentTxn, types.FullCoveredFields, sfi.UnlockConditions, crypto.Hash(sfi.ParentID), tb.wallet.keys[sfi.UnlockConditions.UnlockHash()])
if err != nil {
return err
}
}
// Add the exact output.
claimUnlockConditions, err := tb.wallet.nextPrimarySeedAddress()
if err != nil {
return err
}
newInput := types.SiafundInput{
ParentID: parentTxn.SiafundOutputID(0),
UnlockConditions: parentUnlockConditions,
ClaimUnlockHash: claimUnlockConditions.UnlockHash(),
}
tb.newParents = append(tb.newParents, len(tb.parents))
tb.parents = append(tb.parents, parentTxn)
tb.siafundInputs = append(tb.siafundInputs, len(tb.transaction.SiafundInputs))
tb.transaction.SiafundInputs = append(tb.transaction.SiafundInputs, newInput)
// Mark all outputs that were spent as spent.
for _, sfoid := range spentSfoids {
tb.wallet.spentOutputs[types.OutputID(sfoid)] = tb.wallet.consensusSetHeight
}
return nil
}
// FundSiafunds will add a siafund input of exaclty 'amount' to the
// transaction. A parent transaction may be needed to achieve an input with the
// correct value. The siafund input will not be signed until 'Sign' is called
// on the transaction builder.
//
// TODO: The implementation of FundSiacoins is known to have quirks/bugs
// (non-fatal), and has diverged from the implementation of FundSiacoins. The
// implementations should be converged once again.
func (tb *transactionBuilder) FundSiafunds(amount types.Currency) error {
lockID := tb.wallet.mu.Lock()
defer tb.wallet.mu.Unlock(lockID)
// Create and fund a parent transaction that will add the correct amount of
// siafunds to the transaction.
var fund types.Currency
parentTxn := types.Transaction{}
for scoid, sco := range tb.wallet.siafundOutputs {
// Check that this output has not recently been spent by the wallet.
spendHeight := tb.wallet.spentOutputs[types.OutputID(scoid)]
if spendHeight > tb.wallet.consensusSetHeight-RespendTimeout {
continue
}
outputUnlockConditions := tb.wallet.keys[sco.UnlockHash].unlockConditions
if tb.wallet.consensusSetHeight < outputUnlockConditions.Timelock {
continue
}
// Mark the output as spent.
tb.wallet.spentOutputs[types.OutputID(scoid)] = tb.wallet.consensusSetHeight
// Add a siafund input for this output.
parentClaimUnlockConditions, err := tb.wallet.nextPrimarySeedAddress()
if err != nil {
return err
}
sci := types.SiafundInput{
ParentID: scoid,
UnlockConditions: outputUnlockConditions,
ClaimUnlockHash: parentClaimUnlockConditions.UnlockHash(),
}
parentTxn.SiafundInputs = append(parentTxn.SiafundInputs, sci)
// Add the output to the total fund
fund = fund.Add(sco.Value)
if fund.Cmp(amount) >= 0 {
break
}
}
// Create and add the output that will be used to fund the standard
// transaction.
parentUnlockConditions, err := tb.wallet.nextPrimarySeedAddress()
if err != nil {
return err
}
exactOutput := types.SiafundOutput{
Value: amount,
UnlockHash: parentUnlockConditions.UnlockHash(),
}
parentTxn.SiafundOutputs = append(parentTxn.SiafundOutputs, exactOutput)
// Create a refund output if needed.
if amount.Cmp(fund) != 0 {
refundUnlockConditions, err := tb.wallet.nextPrimarySeedAddress()
if err != nil {
return err
}
refundOutput := types.SiafundOutput{
Value: fund.Sub(amount),
UnlockHash: refundUnlockConditions.UnlockHash(),
}
parentTxn.SiafundOutputs = append(parentTxn.SiafundOutputs, refundOutput)
}
// Sign all of the inputs to the parent trancstion.
for _, sfi := range parentTxn.SiafundInputs {
err := addSignatures(&parentTxn, types.FullCoveredFields, sfi.UnlockConditions, crypto.Hash(sfi.ParentID), tb.wallet.keys[sfi.UnlockConditions.UnlockHash()])
if err != nil {
return err
}
}
// Add the exact output.
claimUnlockConditions, err := tb.wallet.nextPrimarySeedAddress()
if err != nil {
return err
}
newInput := types.SiafundInput{
ParentID: parentTxn.SiafundOutputID(0),
UnlockConditions: parentUnlockConditions,
ClaimUnlockHash: claimUnlockConditions.UnlockHash(),
}
tb.parents = append(tb.parents, parentTxn)
tb.siafundInputs = append(tb.siafundInputs, len(tb.transaction.SiafundInputs))
tb.transaction.SiafundInputs = append(tb.transaction.SiafundInputs, newInput)
return nil
}