Merge pull request #201 from Bytom/v0.1

[bytom/vapor.git] / vendor / github.com / bytom / protocol / bc / types / txoutput.go

diff --git a/vendor/github.com/bytom/protocol/bc/types/txoutput.go b/vendor/github.com/bytom/protocol/bc/types/txoutput.go
new file mode 100644 (file)
index 0000000..2df28e8
--- /dev/null
+++ b/vendor/github.com/bytom/protocol/bc/types/txoutput.go
@@ -0,0 +1,84 @@
+package types
+
+import (
+       "io"
+
+       "github.com/bytom/encoding/blockchain"
+       "github.com/bytom/errors"
+       "github.com/bytom/protocol/bc"
+)
+
+// TxOutput is the top level struct of tx output.
+type TxOutput struct {
+       AssetVersion uint64
+       OutputCommitment
+       // Unconsumed suffixes of the commitment and witness extensible strings.
+       CommitmentSuffix []byte
+}
+
+// NewTxOutput create a new output struct
+func NewTxOutput(assetID bc.AssetID, amount uint64, controlProgram []byte) *TxOutput {
+       return &TxOutput{
+               AssetVersion: 1,
+               OutputCommitment: OutputCommitment{
+                       AssetAmount: bc.AssetAmount{
+                               AssetId: &assetID,
+                               Amount:  amount,
+                       },
+                       VMVersion:      1,
+                       ControlProgram: controlProgram,
+               },
+       }
+}
+
+func (to *TxOutput) readFrom(r *blockchain.Reader) (err error) {
+       if to.AssetVersion, err = blockchain.ReadVarint63(r); err != nil {
+               return errors.Wrap(err, "reading asset version")
+       }
+
+       if to.CommitmentSuffix, err = to.OutputCommitment.readFrom(r, to.AssetVersion); err != nil {
+               return errors.Wrap(err, "reading output commitment")
+       }
+
+       // read and ignore the (empty) output witness
+       _, err = blockchain.ReadVarstr31(r)
+       return errors.Wrap(err, "reading output witness")
+}
+
+func (to *TxOutput) writeTo(w io.Writer) error {
+       if _, err := blockchain.WriteVarint63(w, to.AssetVersion); err != nil {
+               return errors.Wrap(err, "writing asset version")
+       }
+
+       if err := to.writeCommitment(w); err != nil {
+               return errors.Wrap(err, "writing output commitment")
+       }
+
+       if _, err := blockchain.WriteVarstr31(w, nil); err != nil {
+               return errors.Wrap(err, "writing witness")
+       }
+       return nil
+}
+
+func (to *TxOutput) writeCommitment(w io.Writer) error {
+       return to.OutputCommitment.writeExtensibleString(w, to.CommitmentSuffix, to.AssetVersion)
+}
+
+// ComputeOutputID assembles an output entry given a spend commitment and
+// computes and returns its corresponding entry ID.
+func ComputeOutputID(sc *SpendCommitment) (h bc.Hash, err error) {
+       defer func() {
+               if r, ok := recover().(error); ok {
+                       err = r
+               }
+       }()
+       src := &bc.ValueSource{
+               Ref:      &sc.SourceID,
+               Value:    &sc.AssetAmount,
+               Position: sc.SourcePosition,
+       }
+       o := bc.NewOutput(src, &bc.Program{VmVersion: sc.VMVersion, Code: sc.ControlProgram}, 0)
+
+       h = bc.EntryID(o)
+       return h, nil
+}