Permalink
Fetching contributors…
Cannot retrieve contributors at this time
407 lines (337 sloc) 11.6 KB
// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2018 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#ifndef BITCOIN_PRIMITIVES_TRANSACTION_H
#define BITCOIN_PRIMITIVES_TRANSACTION_H
#include <stdint.h>
#include <amount.h>
#include <script/script.h>
#include <serialize.h>
#include <uint256.h>
static const int SERIALIZE_TRANSACTION_NO_WITNESS = 0x40000000;
/** An outpoint - a combination of a transaction hash and an index n into its vout */
class COutPoint
{
public:
uint256 hash;
uint32_t n;
COutPoint(): n((uint32_t) -1) { }
COutPoint(const uint256& hashIn, uint32_t nIn): hash(hashIn), n(nIn) { }
ADD_SERIALIZE_METHODS;
template <typename Stream, typename Operation>
inline void SerializationOp(Stream& s, Operation ser_action) {
READWRITE(hash);
READWRITE(n);
}
void SetNull() { hash.SetNull(); n = (uint32_t) -1; }
bool IsNull() const { return (hash.IsNull() && n == (uint32_t) -1); }
friend bool operator<(const COutPoint& a, const COutPoint& b)
{
int cmp = a.hash.Compare(b.hash);
return cmp < 0 || (cmp == 0 && a.n < b.n);
}
friend bool operator==(const COutPoint& a, const COutPoint& b)
{
return (a.hash == b.hash && a.n == b.n);
}
friend bool operator!=(const COutPoint& a, const COutPoint& b)
{
return !(a == b);
}
std::string ToString() const;
};
/** An input of a transaction. It contains the location of the previous
* transaction's output that it claims and a signature that matches the
* output's public key.
*/
class CTxIn
{
public:
COutPoint prevout;
CScript scriptSig;
uint32_t nSequence;
CScriptWitness scriptWitness; //! Only serialized through CTransaction
/* Setting nSequence to this value for every input in a transaction
* disables nLockTime. */
static const uint32_t SEQUENCE_FINAL = 0xffffffff;
/* Below flags apply in the context of BIP 68*/
/* If this flag set, CTxIn::nSequence is NOT interpreted as a
* relative lock-time. */
static const uint32_t SEQUENCE_LOCKTIME_DISABLE_FLAG = (1 << 31);
/* If CTxIn::nSequence encodes a relative lock-time and this flag
* is set, the relative lock-time has units of 512 seconds,
* otherwise it specifies blocks with a granularity of 1. */
static const uint32_t SEQUENCE_LOCKTIME_TYPE_FLAG = (1 << 22);
/* If CTxIn::nSequence encodes a relative lock-time, this mask is
* applied to extract that lock-time from the sequence field. */
static const uint32_t SEQUENCE_LOCKTIME_MASK = 0x0000ffff;
/* In order to use the same number of bits to encode roughly the
* same wall-clock duration, and because blocks are naturally
* limited to occur every 600s on average, the minimum granularity
* for time-based relative lock-time is fixed at 512 seconds.
* Converting from CTxIn::nSequence to seconds is performed by
* multiplying by 512 = 2^9, or equivalently shifting up by
* 9 bits. */
static const int SEQUENCE_LOCKTIME_GRANULARITY = 9;
CTxIn()
{
nSequence = SEQUENCE_FINAL;
}
explicit CTxIn(COutPoint prevoutIn, CScript scriptSigIn=CScript(), uint32_t nSequenceIn=SEQUENCE_FINAL);
CTxIn(uint256 hashPrevTx, uint32_t nOut, CScript scriptSigIn=CScript(), uint32_t nSequenceIn=SEQUENCE_FINAL);
ADD_SERIALIZE_METHODS;
template <typename Stream, typename Operation>
inline void SerializationOp(Stream& s, Operation ser_action) {
READWRITE(prevout);
READWRITE(scriptSig);
READWRITE(nSequence);
}
friend bool operator==(const CTxIn& a, const CTxIn& b)
{
return (a.prevout == b.prevout &&
a.scriptSig == b.scriptSig &&
a.nSequence == b.nSequence);
}
friend bool operator!=(const CTxIn& a, const CTxIn& b)
{
return !(a == b);
}
std::string ToString() const;
};
/** An output of a transaction. It contains the public key that the next input
* must be able to sign with to claim it.
*/
class CTxOut
{
public:
CAmount nValue;
CScript scriptPubKey;
CTxOut()
{
SetNull();
}
CTxOut(const CAmount& nValueIn, CScript scriptPubKeyIn);
ADD_SERIALIZE_METHODS;
template <typename Stream, typename Operation>
inline void SerializationOp(Stream& s, Operation ser_action) {
READWRITE(nValue);
READWRITE(scriptPubKey);
}
void SetNull()
{
nValue = -1;
scriptPubKey.clear();
}
bool IsNull() const
{
return (nValue == -1);
}
friend bool operator==(const CTxOut& a, const CTxOut& b)
{
return (a.nValue == b.nValue &&
a.scriptPubKey == b.scriptPubKey);
}
friend bool operator!=(const CTxOut& a, const CTxOut& b)
{
return !(a == b);
}
std::string ToString() const;
};
struct CMutableTransaction;
/**
* Basic transaction serialization format:
* - int32_t nVersion
* - std::vector<CTxIn> vin
* - std::vector<CTxOut> vout
* - uint32_t nLockTime
*
* Extended transaction serialization format:
* - int32_t nVersion
* - unsigned char dummy = 0x00
* - unsigned char flags (!= 0)
* - std::vector<CTxIn> vin
* - std::vector<CTxOut> vout
* - if (flags & 1):
* - CTxWitness wit;
* - uint32_t nLockTime
*/
template<typename Stream, typename TxType>
inline void UnserializeTransaction(TxType& tx, Stream& s) {
const bool fAllowWitness = !(s.GetVersion() & SERIALIZE_TRANSACTION_NO_WITNESS);
s >> tx.nVersion;
unsigned char flags = 0;
tx.vin.clear();
tx.vout.clear();
/* Try to read the vin. In case the dummy is there, this will be read as an empty vector. */
s >> tx.vin;
if (tx.vin.size() == 0 && fAllowWitness) {
/* We read a dummy or an empty vin. */
s >> flags;
if (flags != 0) {
s >> tx.vin;
s >> tx.vout;
}
} else {
/* We read a non-empty vin. Assume a normal vout follows. */
s >> tx.vout;
}
if ((flags & 1) && fAllowWitness) {
/* The witness flag is present, and we support witnesses. */
flags ^= 1;
for (size_t i = 0; i < tx.vin.size(); i++) {
s >> tx.vin[i].scriptWitness.stack;
}
}
if (flags) {
/* Unknown flag in the serialization */
throw std::ios_base::failure("Unknown transaction optional data");
}
s >> tx.nLockTime;
}
template<typename Stream, typename TxType>
inline void SerializeTransaction(const TxType& tx, Stream& s) {
const bool fAllowWitness = !(s.GetVersion() & SERIALIZE_TRANSACTION_NO_WITNESS);
s << tx.nVersion;
unsigned char flags = 0;
// Consistency check
if (fAllowWitness) {
/* Check whether witnesses need to be serialized. */
if (tx.HasWitness()) {
flags |= 1;
}
}
if (flags) {
/* Use extended format in case witnesses are to be serialized. */
std::vector<CTxIn> vinDummy;
s << vinDummy;
s << flags;
}
s << tx.vin;
s << tx.vout;
if (flags & 1) {
for (size_t i = 0; i < tx.vin.size(); i++) {
s << tx.vin[i].scriptWitness.stack;
}
}
s << tx.nLockTime;
}
/** The basic transaction that is broadcasted on the network and contained in
* blocks. A transaction can contain multiple inputs and outputs.
*/
class CTransaction
{
public:
// Default transaction version.
static const int32_t CURRENT_VERSION=2;
// Changing the default transaction version requires a two step process: first
// adapting relay policy by bumping MAX_STANDARD_VERSION, and then later date
// bumping the default CURRENT_VERSION at which point both CURRENT_VERSION and
// MAX_STANDARD_VERSION will be equal.
static const int32_t MAX_STANDARD_VERSION=2;
// The local variables are made const to prevent unintended modification
// without updating the cached hash value. However, CTransaction is not
// actually immutable; deserialization and assignment are implemented,
// and bypass the constness. This is safe, as they update the entire
// structure, including the hash.
const std::vector<CTxIn> vin;
const std::vector<CTxOut> vout;
const int32_t nVersion;
const uint32_t nLockTime;
private:
/** Memory only. */
const uint256 hash;
const uint256 m_witness_hash;
uint256 ComputeHash() const;
uint256 ComputeWitnessHash() const;
public:
/** Construct a CTransaction that qualifies as IsNull() */
CTransaction();
/** Convert a CMutableTransaction into a CTransaction. */
CTransaction(const CMutableTransaction &tx);
CTransaction(CMutableTransaction &&tx);
template <typename Stream>
inline void Serialize(Stream& s) const {
SerializeTransaction(*this, s);
}
/** This deserializing constructor is provided instead of an Unserialize method.
* Unserialize is not possible, since it would require overwriting const fields. */
template <typename Stream>
CTransaction(deserialize_type, Stream& s) : CTransaction(CMutableTransaction(deserialize, s)) {}
bool IsNull() const {
return vin.empty() && vout.empty();
}
const uint256& GetHash() const { return hash; }
const uint256& GetWitnessHash() const { return m_witness_hash; };
// Return sum of txouts.
CAmount GetValueOut() const;
// GetValueIn() is a method on CCoinsViewCache, because
// inputs must be known to compute value in.
/**
* Get the total transaction size in bytes, including witness data.
* "Total Size" defined in BIP141 and BIP144.
* @return Total transaction size in bytes
*/
unsigned int GetTotalSize() const;
bool IsCoinBase() const
{
return (vin.size() == 1 && vin[0].prevout.IsNull());
}
friend bool operator==(const CTransaction& a, const CTransaction& b)
{
return a.hash == b.hash;
}
friend bool operator!=(const CTransaction& a, const CTransaction& b)
{
return a.hash != b.hash;
}
std::string ToString() const;
bool HasWitness() const
{
for (size_t i = 0; i < vin.size(); i++) {
if (!vin[i].scriptWitness.IsNull()) {
return true;
}
}
return false;
}
};
/** A mutable version of CTransaction. */
struct CMutableTransaction
{
std::vector<CTxIn> vin;
std::vector<CTxOut> vout;
int32_t nVersion;
uint32_t nLockTime;
CMutableTransaction();
explicit CMutableTransaction(const CTransaction& tx);
template <typename Stream>
inline void Serialize(Stream& s) const {
SerializeTransaction(*this, s);
}
template <typename Stream>
inline void Unserialize(Stream& s) {
UnserializeTransaction(*this, s);
}
template <typename Stream>
CMutableTransaction(deserialize_type, Stream& s) {
Unserialize(s);
}
/** Compute the hash of this CMutableTransaction. This is computed on the
* fly, as opposed to GetHash() in CTransaction, which uses a cached result.
*/
uint256 GetHash() const;
bool HasWitness() const
{
for (size_t i = 0; i < vin.size(); i++) {
if (!vin[i].scriptWitness.IsNull()) {
return true;
}
}
return false;
}
};
typedef std::shared_ptr<const CTransaction> CTransactionRef;
static inline CTransactionRef MakeTransactionRef() { return std::make_shared<const CTransaction>(); }
template <typename Tx> static inline CTransactionRef MakeTransactionRef(Tx&& txIn) { return std::make_shared<const CTransaction>(std::forward<Tx>(txIn)); }
#endif // BITCOIN_PRIMITIVES_TRANSACTION_H