diff options
Diffstat (limited to 'data/transactions/signedtxn.go')
| -rw-r--r-- | data/transactions/signedtxn.go | 32 |
1 files changed, 31 insertions, 1 deletions
diff --git a/data/transactions/signedtxn.go b/data/transactions/signedtxn.go index 8b54300d9..c30cd5303 100644 --- a/data/transactions/signedtxn.go +++ b/data/transactions/signedtxn.go @@ -18,6 +18,7 @@ package transactions import ( "errors" + "fmt" "github.com/algorand/go-algorand/crypto" "github.com/algorand/go-algorand/data/basics" @@ -87,7 +88,7 @@ func (s SignedTxnInBlock) GetEncodedLength() int { // This is just s.AuthAddr or, if s.AuthAddr is zero, s.Txn.Sender. // It's provided as a convenience method. func (s SignedTxn) Authorizer() basics.Address { - if (s.AuthAddr == basics.Address{}) { + if s.AuthAddr.IsZero() { return s.Txn.Sender } return s.AuthAddr @@ -129,3 +130,32 @@ func WrapSignedTxnsWithAD(txgroup []SignedTxn) []SignedTxnWithAD { } return txgroupad } + +// FeeCredit computes the amount of fee credit that can be spent on +// inner txns because it was more than required. +func FeeCredit(txgroup []SignedTxn, minFee uint64) (uint64, error) { + minFeeCount := uint64(0) + feesPaid := uint64(0) + for _, stxn := range txgroup { + if stxn.Txn.Type != protocol.CompactCertTx { + minFeeCount++ + } + feesPaid = basics.AddSaturate(feesPaid, stxn.Txn.Fee.Raw) + } + feeNeeded, overflow := basics.OMul(minFee, minFeeCount) + if overflow { + return 0, fmt.Errorf("txgroup fee requirement overflow") + } + // feesPaid may have saturated. That's ok. Since we know + // feeNeeded did not overflow, simple comparison tells us + // feesPaid was enough. + if feesPaid < feeNeeded { + return 0, fmt.Errorf("txgroup had %d in fees, which is less than the minimum %d * %d", + feesPaid, minFeeCount, minFee) + } + // Now, if feesPaid *did* saturate, you will not get "credit" for + // all those fees while executing AVM code that might create + // transactions. But you'll get the max uint64 - good luck + // spending it. + return feesPaid - feeNeeded, nil +} |