blockchain/txbuilder/estimate.go

   1 package txbuilder
   2
   3 import (
   4         "github.com/bytom/consensus"
   5         "github.com/bytom/consensus/segwit"
   6         "github.com/bytom/protocol/bc/types"
   7         "github.com/bytom/protocol/vm/vmutil"
   8 )
   9
  10 const (
  11         baseSize       = int64(176) // inputSize(112) + outputSize(64)
  12         baseP2WPKHSize = int64(98)
  13         baseP2WPKHGas  = int64(1409)
  14 )
  15
  16 var (
  17         //ChainTxUtxoNum maximum utxo quantity in a tx
  18         ChainTxUtxoNum = 5
  19         //ChainTxMergeGas chain tx gas
  20         ChainTxMergeGas = uint64(10000000)
  21 )
  22
  23 // EstimateTxGasInfo estimate transaction consumed gas
  24 type EstimateTxGasInfo struct {
  25         TotalNeu    int64 `json:"total_neu"`
  26         FlexibleNeu int64 `json:"flexible_neu"`
  27         StorageNeu  int64 `json:"storage_neu"`
  28         VMNeu       int64 `json:"vm_neu"`
  29         ChainTxNeu  int64 `json:"chain_tx_neu"`
  30 }
  31
  32 func EstimateChainTxGas(templates []Template) (*EstimateTxGasInfo, error) {
  33         estimated, err := EstimateTxGas(templates[len(templates)-1])
  34         if err != nil {
  35                 return nil, err
  36         }
  37
  38         if len(templates) > 1 {
  39                 estimated.ChainTxNeu = int64(ChainTxMergeGas) * int64(len(templates)-1)
  40         }
  41         return estimated, nil
  42 }
  43
  44 // EstimateTxGas estimate consumed neu for transaction
  45 func EstimateTxGas(template Template) (*EstimateTxGasInfo, error) {
  46         var baseP2WSHSize, totalWitnessSize, baseP2WSHGas, totalP2WPKHGas, totalP2WSHGas, totalIssueGas int64
  47         for pos, input := range template.Transaction.TxData.Inputs {
  48                 switch input.InputType() {
  49                 case types.SpendInputType:
  50                         controlProgram := input.ControlProgram()
  51                         if segwit.IsP2WPKHScript(controlProgram) {
  52                                 totalWitnessSize += baseP2WPKHSize
  53                                 totalP2WPKHGas += baseP2WPKHGas
  54                         } else if segwit.IsP2WSHScript(controlProgram) {
  55                                 baseP2WSHSize, baseP2WSHGas = estimateP2WSHGas(template.SigningInstructions[pos])
  56                                 totalWitnessSize += baseP2WSHSize
  57                                 totalP2WSHGas += baseP2WSHGas
  58                         }
  59
  60                 case types.IssuanceInputType:
  61                         issuanceProgram := input.IssuanceProgram()
  62                         if height := vmutil.GetIssuanceProgramRestrictHeight(issuanceProgram); height > 0 {
  63                                 // the gas for issue program with checking block height
  64                                 totalIssueGas += 5
  65                         }
  66                         baseIssueSize, baseIssueGas := estimateIssueGas(template.SigningInstructions[pos])
  67                         totalWitnessSize += baseIssueSize
  68                         totalIssueGas += baseIssueGas
  69                 }
  70         }
  71
  72         flexibleGas := int64(0)
  73         if totalP2WPKHGas > 0 {
  74                 flexibleGas += baseP2WPKHGas + (baseSize+baseP2WPKHSize)*consensus.StorageGasRate
  75         } else if totalP2WSHGas > 0 {
  76                 flexibleGas += baseP2WSHGas + (baseSize+baseP2WSHSize)*consensus.StorageGasRate
  77         } else if totalIssueGas > 0 {
  78                 totalIssueGas += baseP2WPKHGas
  79                 totalWitnessSize += baseSize + baseP2WPKHSize
  80         }
  81
  82         // the total transaction storage gas
  83         totalTxSizeGas := (int64(template.Transaction.TxData.SerializedSize) + totalWitnessSize) * consensus.StorageGasRate
  84
  85         // the total transaction gas is composed of storage and virtual machines
  86         totalGas := totalTxSizeGas + totalP2WPKHGas + totalP2WSHGas + totalIssueGas + flexibleGas
  87         return &EstimateTxGasInfo{
  88                 TotalNeu:    totalGas * consensus.VMGasRate,
  89                 FlexibleNeu: flexibleGas * consensus.VMGasRate,
  90                 StorageNeu:  totalTxSizeGas * consensus.VMGasRate,
  91                 VMNeu:       (totalP2WPKHGas + totalP2WSHGas + totalIssueGas) * consensus.VMGasRate,
  92         }, nil
  93 }
  94
  95 // estimateP2WSH return the witness size and the gas consumed to execute the virtual machine for P2WSH program
  96 func estimateP2WSHGas(sigInst *SigningInstruction) (int64, int64) {
  97         var witnessSize, gas int64
  98         for _, witness := range sigInst.WitnessComponents {
  99                 switch t := witness.(type) {
 100                 case *SignatureWitness:
 101                         witnessSize += 33*int64(len(t.Keys)) + 65*int64(t.Quorum)
 102                         gas += 1131*int64(len(t.Keys)) + 72*int64(t.Quorum) + 659
 103                         if int64(len(t.Keys)) == 1 && int64(t.Quorum) == 1 {
 104                                 gas += 27
 105                         }
 106                 case *RawTxSigWitness:
 107                         witnessSize += 33*int64(len(t.Keys)) + 65*int64(t.Quorum)
 108                         gas += 1131*int64(len(t.Keys)) + 72*int64(t.Quorum) + 659
 109                         if int64(len(t.Keys)) == 1 && int64(t.Quorum) == 1 {
 110                                 gas += 27
 111                         }
 112                 }
 113         }
 114         return witnessSize, gas
 115 }
 116
 117 // estimateIssueGas return the witness size and the gas consumed to execute the virtual machine for issuance program
 118 func estimateIssueGas(sigInst *SigningInstruction) (int64, int64) {
 119         var witnessSize, gas int64
 120         for _, witness := range sigInst.WitnessComponents {
 121                 switch t := witness.(type) {
 122                 case *SignatureWitness:
 123                         witnessSize += 65 * int64(t.Quorum)
 124                         gas += 1065*int64(len(t.Keys)) + 72*int64(t.Quorum) + 316
 125                 case *RawTxSigWitness:
 126                         witnessSize += 65 * int64(t.Quorum)
 127                         gas += 1065*int64(len(t.Keys)) + 72*int64(t.Quorum) + 316
 128                 }
 129         }
 130         return witnessSize, gas
 131 }