90 lines
2.6 KiB
Go
90 lines
2.6 KiB
Go
// Copyright (c) 2013-2014 Conformal Systems LLC.
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// Use of this source code is governed by an ISC
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// license that can be found in the LICENSE file.
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package btcutil
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import (
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"bytes"
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"github.com/conformal/btcwire"
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)
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// TxIndexUnknown is the value returned for a transaction index that is unknown.
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// This is typically because the transaction has not been inserted into a block
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// yet.
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const TxIndexUnknown = -1
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// Tx defines a bitcoin transaction that provides easier and more efficient
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// manipulation of raw transactions. It also memoizes the hash for the
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// transaction on its first access so subsequent accesses don't have to repeat
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// the relatively expensive hashing operations.
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type Tx struct {
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msgTx *btcwire.MsgTx // Underlying MsgTx
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serializedTx []byte // Serialized bytes for the transaction
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txSha *btcwire.ShaHash // Cached transaction hash
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txIndex int // Position within a block or TxIndexUnknown
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}
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// MsgTx returns the underlying btcwire.MsgTx for the transaction.
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func (t *Tx) MsgTx() *btcwire.MsgTx {
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// Return the cached transaction.
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return t.msgTx
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}
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// Sha returns the hash of the transaction. This is equivalent to
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// calling TxSha on the underlying btcwire.MsgTx, however it caches the
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// result so subsequent calls are more efficient.
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func (t *Tx) Sha() *btcwire.ShaHash {
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// Return the cached hash if it has already been generated.
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if t.txSha != nil {
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return t.txSha
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}
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// Generate the transaction hash. Ignore the error since TxSha can't
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// currently fail.
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sha, _ := t.msgTx.TxSha()
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// Cache the hash and return it.
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t.txSha = &sha
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return &sha
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}
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// Index returns the saved index of the transaction within a block. This value
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// will be TxIndexUnknown if it hasn't already explicitly been set.
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func (t *Tx) Index() int {
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return t.txIndex
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}
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// SetIndex sets the index of the transaction in within a block.
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func (t *Tx) SetIndex(index int) {
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t.txIndex = index
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}
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// NewTx returns a new instance of a bitcoin transaction given an underlying
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// btcwire.MsgTx. See Tx.
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func NewTx(msgTx *btcwire.MsgTx) *Tx {
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return &Tx{
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msgTx: msgTx,
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txIndex: TxIndexUnknown,
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}
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}
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// NewTxFromBytes returns a new instance of a bitcoin transaction given the
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// serialized bytes. See Tx.
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func NewTxFromBytes(serializedTx []byte) (*Tx, error) {
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// Deserialize the bytes into a MsgTx.
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var msgTx btcwire.MsgTx
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br := bytes.NewBuffer(serializedTx)
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err := msgTx.Deserialize(br)
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if err != nil {
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return nil, err
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}
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t := Tx{
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msgTx: &msgTx,
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serializedTx: serializedTx,
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txIndex: TxIndexUnknown,
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}
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return &t, nil
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}
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