protocol/bc/types/output_commitment.go

   1 package types
   2
   3 import (
   4         "fmt"
   5         "io"
   6
   7         "github.com/vapor/encoding/blockchain"
   8         "github.com/vapor/errors"
   9         "github.com/vapor/protocol/bc"
  10 )
  11
  12 // OutputCommitment contains the commitment data for a transaction output.
  13 type OutputCommitment struct {
  14         bc.AssetAmount
  15         VMVersion      uint64
  16         ControlProgram []byte
  17 }
  18
  19 func (oc *OutputCommitment) writeExtensibleString(w io.Writer, suffix []byte, assetVersion uint64) error {
  20         _, err := blockchain.WriteExtensibleString(w, suffix, func(w io.Writer) error {
  21                 return oc.writeContents(w, suffix, assetVersion)
  22         })
  23         return err
  24 }
  25
  26 func (oc *OutputCommitment) writeContents(w io.Writer, suffix []byte, assetVersion uint64) (err error) {
  27         if assetVersion == 1 {
  28                 if _, err = oc.AssetAmount.WriteTo(w); err != nil {
  29                         return errors.Wrap(err, "writing asset amount")
  30                 }
  31                 if _, err = blockchain.WriteVarint63(w, oc.VMVersion); err != nil {
  32                         return errors.Wrap(err, "writing vm version")
  33                 }
  34                 if _, err = blockchain.WriteVarstr31(w, oc.ControlProgram); err != nil {
  35                         return errors.Wrap(err, "writing control program")
  36                 }
  37         }
  38         if len(suffix) > 0 {
  39                 _, err = w.Write(suffix)
  40         }
  41         return errors.Wrap(err, "writing suffix")
  42 }
  43
  44 func (oc *OutputCommitment) readFrom(r *blockchain.Reader, assetVersion uint64) (suffix []byte, err error) {
  45         return blockchain.ReadExtensibleString(r, func(r *blockchain.Reader) error {
  46                 if assetVersion == 1 {
  47                         if err := oc.AssetAmount.ReadFrom(r); err != nil {
  48                                 return errors.Wrap(err, "reading asset+amount")
  49                         }
  50                         oc.VMVersion, err = blockchain.ReadVarint63(r)
  51                         if err != nil {
  52                                 return errors.Wrap(err, "reading VM version")
  53                         }
  54                         if oc.VMVersion != 1 {
  55                                 return fmt.Errorf("unrecognized VM version %d for asset version 1", oc.VMVersion)
  56                         }
  57                         oc.ControlProgram, err = blockchain.ReadVarstr31(r)
  58                         return errors.Wrap(err, "reading control program")
  59                 }
  60                 return nil
  61         })
  62 }