claim/bytom/protocolbc/types/output_commitment.go

   1 package types
   2
   3 import (
   4         "fmt"
   5         "io"
   6
   7         "github.com/vapor/crypto/sha3pool"
   8         "github.com/vapor/encoding/blockchain"
   9         "github.com/vapor/errors"
  10         "github.com/vapor/protocol/bc"
  11 )
  12
  13 // OutputCommitment contains the commitment data for a transaction output.
  14 type OutputCommitment struct {
  15         bc.AssetAmount
  16         VMVersion      uint64
  17         ControlProgram []byte
  18 }
  19
  20 func (oc *OutputCommitment) writeExtensibleString(w io.Writer, suffix []byte, assetVersion uint64) error {
  21         _, err := blockchain.WriteExtensibleString(w, suffix, func(w io.Writer) error {
  22                 return oc.writeContents(w, suffix, assetVersion)
  23         })
  24         return err
  25 }
  26
  27 func (oc *OutputCommitment) writeContents(w io.Writer, suffix []byte, assetVersion uint64) (err error) {
  28         if assetVersion == 1 {
  29                 if _, err = oc.AssetAmount.WriteTo(w); err != nil {
  30                         return errors.Wrap(err, "writing asset amount")
  31                 }
  32                 if _, err = blockchain.WriteVarint63(w, oc.VMVersion); err != nil {
  33                         return errors.Wrap(err, "writing vm version")
  34                 }
  35                 if _, err = blockchain.WriteVarstr31(w, oc.ControlProgram); err != nil {
  36                         return errors.Wrap(err, "writing control program")
  37                 }
  38         }
  39         if len(suffix) > 0 {
  40                 _, err = w.Write(suffix)
  41         }
  42         return errors.Wrap(err, "writing suffix")
  43 }
  44
  45 func (oc *OutputCommitment) readFrom(r *blockchain.Reader, assetVersion uint64) (suffix []byte, err error) {
  46         return blockchain.ReadExtensibleString(r, func(r *blockchain.Reader) error {
  47                 if assetVersion == 1 {
  48                         if err := oc.AssetAmount.ReadFrom(r); err != nil {
  49                                 return errors.Wrap(err, "reading asset+amount")
  50                         }
  51                         oc.VMVersion, err = blockchain.ReadVarint63(r)
  52                         if err != nil {
  53                                 return errors.Wrap(err, "reading VM version")
  54                         }
  55                         if oc.VMVersion != 1 {
  56                                 return fmt.Errorf("unrecognized VM version %d for asset version 1", oc.VMVersion)
  57                         }
  58                         oc.ControlProgram, err = blockchain.ReadVarstr31(r)
  59                         return errors.Wrap(err, "reading control program")
  60                 }
  61                 return nil
  62         })
  63 }
  64
  65 // Hash convert suffix && assetVersion to bc.Hash
  66 func (oc *OutputCommitment) Hash(suffix []byte, assetVersion uint64) (outputhash bc.Hash) {
  67         h := sha3pool.Get256()
  68         defer sha3pool.Put256(h)
  69         oc.writeExtensibleString(h, suffix, assetVersion)
  70         outputhash.ReadFrom(h)
  71         return outputhash
  72 }