func (tx *Transaction) BtcDecode(r io.Reader) error {
var version [4]byte
if _, err := r.Read(version[:]); err != nil {
return err
}
tx.Version = binary.LittleEndian.Uint32(version[:])
inCount, err := varint.Deserialize(r)
if err != nil {
return err
}
tx.In = make([]*TxIn, inCount)
for i := 0; i < int(inCount); i++ {
tx.In[i] = &TxIn{}
tx.In[i].BtcDecode(r)
}
outCount, err := varint.Deserialize(r)
if err != nil {
return err
}
tx.Out = make([]*TxOut, outCount)
for i := 0; i < int(outCount); i++ {
tx.Out[i] = &TxOut{}
tx.Out[i].BtcDecode(r)
}
var lockTime [4]byte
if _, err := r.Read(lockTime[:]); err != nil {
return err
}
tx.LockTime = binary.LittleEndian.Uint32(lockTime[:])
return nil
}
func (tx *TxOut) BtcDecode(r io.Reader) error {
var value [8]byte
if _, err := r.Read(value[:]); err != nil {
return err
}
tx.Value = int64(binary.LittleEndian.Uint64(value[:]))
pkscriptLen, err := varint.Deserialize(r)
if err != nil {
return err
}
pkscript := make([]byte, pkscriptLen)
if _, err := r.Read(pkscript); err != nil {
return err
}
tx.PKScript = pkscript
return nil
}
func (tx *TxIn) BtcDecode(r io.Reader) error {
tx.PreviousTxOut.BtcDecode(r)
scriptLen, err := varint.Deserialize(r)
if err != nil {
return err
}
sig := make([]byte, scriptLen)
if _, err := r.Read(sig); err != nil {
return err
}
tx.ScriptSignature = sig
var seq [4]byte
if _, err := r.Read(seq[:]); err != nil {
return err
}
tx.Sequence = binary.LittleEndian.Uint32(seq[:])
return nil
}
func TestVarintSerialize(t *testing.T) {
tests := []struct {
val uint64 // Value to get the serialized size for
size int // Expected serialized size
}{
// Single byte
{0, 1},
// Max single byte
{0xfc, 1},
// Min 2-byte
{0xfd, 3},
// Max 2-byte
{0xffff, 3},
// Min 4-byte
{0x10000, 5},
// Max 4-byte
{0xffffffff, 5},
// Min 8-byte
{0x100000000, 9},
// Max 8-byte
{0xffffffffffffffff, 9},
}
for i, test := range tests {
serialized := varint.Serialize(test.val)
if len(serialized) != test.size {
t.Errorf("Size #%d got: %d, want: %d", i, len(serialized), test.size)
continue
}
value, err := varint.Deserialize(bytes.NewBuffer(serialized))
if err != nil {
t.Fatal(err)
}
if value != test.val {
t.Errorf("Value: Expected %v, got %v", i, test.val, value)
continue
}
}
}