common/arithmetic/calculate.go

   1 package arithmetic
   2
   3 import (
   4         "github.com/bytom/vapor/consensus"
   5         "github.com/bytom/vapor/math/checked"
   6         "github.com/bytom/vapor/protocol/bc/types"
   7 )
   8
   9 // CalculateTxFee calculate transaction fee
  10 func CalculateTxFee(tx *types.Tx) (fee uint64, err error) {
  11         var ok bool
  12         for _, input := range tx.Inputs {
  13                 if input.InputType() == types.CoinbaseInputType {
  14                         return 0, nil
  15                 }
  16                 if input.AssetID() == *consensus.BTMAssetID {
  17                         if fee, ok = checked.AddUint64(fee, input.Amount()); !ok {
  18                                 return 0, checked.ErrOverflow
  19                         }
  20                 }
  21         }
  22
  23         for _, output := range tx.Outputs {
  24                 if *output.AssetAmount().AssetId == *consensus.BTMAssetID {
  25                         if fee, ok = checked.SubUint64(fee, output.AssetAmount().Amount); !ok {
  26                                 return 0, checked.ErrOverflow
  27                         }
  28                 }
  29         }
  30         return
  31 }