transaction.h

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// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2015 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 <amount.h>
#include <script/script.h>
#include <serialize.h>
#include <uint256.h>

enum {
    TRANSACTION_NORMAL = 0,
    TRANSACTION_PROVIDER_REGISTER = 1,
    TRANSACTION_PROVIDER_UPDATE_SERVICE = 2,
    TRANSACTION_PROVIDER_UPDATE_REGISTRAR = 3,
    TRANSACTION_PROVIDER_UPDATE_REVOKE = 4,
    TRANSACTION_COINBASE = 5,
    TRANSACTION_QUORUM_COMMITMENT = 6,
};

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;
    std::string ToStringShort() const;
};

class CTxIn
{
public:
    COutPoint prevout;
    CScript scriptSig;
    uint32_t nSequence;

    /* 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);
    }

    friend bool operator<(const CTxIn& a, const CTxIn& b)
    {
        return a.prevout<b.prevout;
    }

    std::string ToString() const;
};

class CTxOut
{
public:
    CAmount nValue;
    CScript scriptPubKey;
    int nRounds;

    CTxOut()
    {
        SetNull();
    }

    CTxOut(const CAmount& nValueIn, CScript scriptPubKeyIn, int nRoundsIn = -10);

    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();
        nRounds = -10; // an initial value, should be no way to get this by calculations
    }

    bool IsNull() const
    {
        return (nValue == -1);
    }

    friend bool operator==(const CTxOut& a, const CTxOut& b)
    {
        return (a.nValue       == b.nValue &&
                a.scriptPubKey == b.scriptPubKey &&
                a.nRounds      == b.nRounds);
    }

    friend bool operator!=(const CTxOut& a, const CTxOut& b)
    {
        return !(a == b);
    }

    std::string ToString() const;
};

struct CMutableTransaction;

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=3;

    // 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 int16_t nVersion;
    const int16_t nType;
    const uint32_t nLockTime;
    const std::vector<uint8_t> vExtraPayload; // only available for special transaction types

private:
    const uint256 hash;

    uint256 ComputeHash() const;

public:
    CTransaction();

    CTransaction(const CMutableTransaction &tx);
    CTransaction(CMutableTransaction &&tx);

    template <typename Stream>
    inline void Serialize(Stream& s) const {
        int32_t n32bitVersion = this->nVersion | (this->nType << 16);
        s << n32bitVersion;
        s << vin;
        s << vout;
        s << nLockTime;
        if (this->nVersion == 3 && this->nType != TRANSACTION_NORMAL)
            s << vExtraPayload;
    }

    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;
    }

    // Return sum of txouts.
    CAmount GetValueOut() const;
    // GetValueIn() is a method on CCoinsViewCache, because
    // inputs must be known to compute value in.

    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;
};

struct CMutableTransaction
{
    std::vector<CTxIn> vin;
    std::vector<CTxOut> vout;
    int16_t nVersion;
    int16_t nType;
    uint32_t nLockTime;
    std::vector<uint8_t> vExtraPayload; // only available for special transaction types

    CMutableTransaction();
    CMutableTransaction(const CTransaction& tx);

    ADD_SERIALIZE_METHODS;

    template <typename Stream, typename Operation>
    inline void SerializationOp(Stream& s, Operation ser_action) {
        int32_t n32bitVersion = this->nVersion | (this->nType << 16);
        READWRITE(n32bitVersion);
        if (ser_action.ForRead()) {
            this->nVersion = (int16_t) (n32bitVersion & 0xffff);
            this->nType = (int16_t) ((n32bitVersion >> 16) & 0xffff);
        }
        READWRITE(vin);
        READWRITE(vout);
        READWRITE(nLockTime);
        if (this->nVersion == 3 && this->nType != TRANSACTION_NORMAL) {
            READWRITE(vExtraPayload);
        }
    }

    template <typename Stream>
    CMutableTransaction(deserialize_type, Stream& s) {
        Unserialize(s);
    }

    uint256 GetHash() const;

    std::string ToString() const;

    friend bool operator==(const CMutableTransaction& a, const CMutableTransaction& b)
    {
        return a.GetHash() == b.GetHash();
    }

    friend bool operator!=(const CMutableTransaction& a, const CMutableTransaction& b)
    {
        return !(a == b);
    }

};

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)); }

struct CompareInputBIP69
{
    inline bool operator()(const CTxIn& a, const CTxIn& b) const
    {
        if (a.prevout.hash == b.prevout.hash) return a.prevout.n < b.prevout.n;

        uint256 hasha = a.prevout.hash;
        uint256 hashb = b.prevout.hash;

        typedef std::reverse_iterator<const unsigned char*> rev_it;
        rev_it rita = rev_it(hasha.end());
        rev_it ritb = rev_it(hashb.end());

        return std::lexicographical_compare(rita, rita + hasha.size(), ritb, ritb + hashb.size());
    }
};

struct CompareOutputBIP69
{
    inline bool operator()(const CTxOut& a, const CTxOut& b) const
    {
        return a.nValue < b.nValue || (a.nValue == b.nValue && a.scriptPubKey < b.scriptPubKey);
    }
};

#endif // BITCOIN_PRIMITIVES_TRANSACTION_H