neobytes/src/core.cpp

// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2013 The Bitcoin developers
// Distributed under the MIT/X11 software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#include "core.h"
#include "util.h"

std::string COutPoint::ToString() const
{
    return strprintf("COutPoint(%s, %u)", hash.ToString().substr(0,10).c_str(), n);
}

void COutPoint::print() const
{
    printf("%s\n", ToString().c_str());
}

CTxIn::CTxIn(COutPoint prevoutIn, CScript scriptSigIn, unsigned int nSequenceIn)
{
    prevout = prevoutIn;
    scriptSig = scriptSigIn;
    nSequence = nSequenceIn;
}

CTxIn::CTxIn(uint256 hashPrevTx, unsigned int nOut, CScript scriptSigIn, unsigned int nSequenceIn)
{
    prevout = COutPoint(hashPrevTx, nOut);
    scriptSig = scriptSigIn;
    nSequence = nSequenceIn;
}

std::string CTxIn::ToString() const
{
    std::string str;
    str += "CTxIn(";
    str += prevout.ToString();
    if (prevout.IsNull())
        str += strprintf(", coinbase %s", HexStr(scriptSig).c_str());
    else
        str += strprintf(", scriptSig=%s", scriptSig.ToString().substr(0,24).c_str());
    if (nSequence != std::numeric_limits<unsigned int>::max())
        str += strprintf(", nSequence=%u", nSequence);
    str += ")";
    return str;
}

void CTxIn::print() const
{
    printf("%s\n", ToString().c_str());
}

CTxOut::CTxOut(int64 nValueIn, CScript scriptPubKeyIn)
{
    nValue = nValueIn;
    scriptPubKey = scriptPubKeyIn;
}

uint256 CTxOut::GetHash() const
{
    return SerializeHash(*this);
}

std::string CTxOut::ToString() const
{
    if (scriptPubKey.size() < 6)
        return "CTxOut(error)";
    return strprintf("CTxOut(nValue=%"PRI64d".%08"PRI64d", scriptPubKey=%s)", nValue / COIN, nValue % COIN, scriptPubKey.ToString().substr(0,30).c_str());
}

void CTxOut::print() const
{
    printf("%s\n", ToString().c_str());
}

uint256 CTransaction::GetHash() const
{
    return SerializeHash(*this);
}

bool CTransaction::IsNewerThan(const CTransaction& old) const
{
    if (vin.size() != old.vin.size())
        return false;
    for (unsigned int i = 0; i < vin.size(); i++)
        if (vin[i].prevout != old.vin[i].prevout)
            return false;

    bool fNewer = false;
    unsigned int nLowest = std::numeric_limits<unsigned int>::max();
    for (unsigned int i = 0; i < vin.size(); i++)
    {
        if (vin[i].nSequence != old.vin[i].nSequence)
        {
            if (vin[i].nSequence <= nLowest)
            {
                fNewer = false;
                nLowest = vin[i].nSequence;
            }
            if (old.vin[i].nSequence < nLowest)
            {
                fNewer = true;
                nLowest = old.vin[i].nSequence;
            }
        }
    }
    return fNewer;
}

std::string CTransaction::ToString() const
{
    std::string str;
    str += strprintf("CTransaction(hash=%s, ver=%d, vin.size=%"PRIszu", vout.size=%"PRIszu", nLockTime=%u)\n",
        GetHash().ToString().substr(0,10).c_str(),
        nVersion,
        vin.size(),
        vout.size(),
        nLockTime);
    for (unsigned int i = 0; i < vin.size(); i++)
        str += "    " + vin[i].ToString() + "\n";
    for (unsigned int i = 0; i < vout.size(); i++)
        str += "    " + vout[i].ToString() + "\n";
    return str;
}

void CTransaction::print() const
{
    printf("%s", ToString().c_str());
}

// Amount compression:
// * If the amount is 0, output 0
// * first, divide the amount (in base units) by the largest power of 10 possible; call the exponent e (e is max 9)
// * if e<9, the last digit of the resulting number cannot be 0; store it as d, and drop it (divide by 10)
//   * call the result n
//   * output 1 + 10*(9*n + d - 1) + e
// * if e==9, we only know the resulting number is not zero, so output 1 + 10*(n - 1) + 9
// (this is decodable, as d is in [1-9] and e is in [0-9])

uint64 CTxOutCompressor::CompressAmount(uint64 n)
{
    if (n == 0)
        return 0;
    int e = 0;
    while (((n % 10) == 0) && e < 9) {
        n /= 10;
        e++;
    }
    if (e < 9) {
        int d = (n % 10);
        assert(d >= 1 && d <= 9);
        n /= 10;
        return 1 + (n*9 + d - 1)*10 + e;
    } else {
        return 1 + (n - 1)*10 + 9;
    }
}

uint64 CTxOutCompressor::DecompressAmount(uint64 x)
{
    // x = 0  OR  x = 1+10*(9*n + d - 1) + e  OR  x = 1+10*(n - 1) + 9
    if (x == 0)
        return 0;
    x--;
    // x = 10*(9*n + d - 1) + e
    int e = x % 10;
    x /= 10;
    uint64 n = 0;
    if (e < 9) {
        // x = 9*n + d - 1
        int d = (x % 9) + 1;
        x /= 9;
        // x = n
        n = x*10 + d;
    } else {
        n = x+1;
    }
    while (e) {
        n *= 10;
        e--;
    }
    return n;
}

// calculate number of bytes for the bitmask, and its number of non-zero bytes
// each bit in the bitmask represents the availability of one output, but the
// availabilities of the first two outputs are encoded separately
void CCoins::CalcMaskSize(unsigned int &nBytes, unsigned int &nNonzeroBytes) const {
    unsigned int nLastUsedByte = 0;
    for (unsigned int b = 0; 2+b*8 < vout.size(); b++) {
        bool fZero = true;
        for (unsigned int i = 0; i < 8 && 2+b*8+i < vout.size(); i++) {
            if (!vout[2+b*8+i].IsNull()) {
                fZero = false;
                continue;
            }
        }
        if (!fZero) {
            nLastUsedByte = b + 1;
            nNonzeroBytes++;
        }
    }
    nBytes += nLastUsedByte;
}

bool CCoins::Spend(const COutPoint &out, CTxInUndo &undo) {
    if (out.n >= vout.size())
        return false;
    if (vout[out.n].IsNull())
        return false;
    undo = CTxInUndo(vout[out.n]);
    vout[out.n].SetNull();
    Cleanup();
    if (vout.size() == 0) {
        undo.nHeight = nHeight;
        undo.fCoinBase = fCoinBase;
        undo.nVersion = this->nVersion;
    }
    return true;
}

bool CCoins::Spend(int nPos) {
    CTxInUndo undo;
    COutPoint out(0, nPos);
    return Spend(out, undo);
}

uint256 CBlockHeader::GetHash() const
{
    return Hash(BEGIN(nVersion), END(nNonce));
}

uint256 CBlock::BuildMerkleTree() const
{
    vMerkleTree.clear();
    BOOST_FOREACH(const CTransaction& tx, vtx)
        vMerkleTree.push_back(tx.GetHash());
    int j = 0;
    for (int nSize = vtx.size(); nSize > 1; nSize = (nSize + 1) / 2)
    {
        for (int i = 0; i < nSize; i += 2)
        {
            int i2 = std::min(i+1, nSize-1);
            vMerkleTree.push_back(Hash(BEGIN(vMerkleTree[j+i]),  END(vMerkleTree[j+i]),
                                       BEGIN(vMerkleTree[j+i2]), END(vMerkleTree[j+i2])));
        }
        j += nSize;
    }
    return (vMerkleTree.empty() ? 0 : vMerkleTree.back());
}

std::vector<uint256> CBlock::GetMerkleBranch(int nIndex) const
{
    if (vMerkleTree.empty())
        BuildMerkleTree();
    std::vector<uint256> vMerkleBranch;
    int j = 0;
    for (int nSize = vtx.size(); nSize > 1; nSize = (nSize + 1) / 2)
    {
        int i = std::min(nIndex^1, nSize-1);
        vMerkleBranch.push_back(vMerkleTree[j+i]);
        nIndex >>= 1;
        j += nSize;
    }
    return vMerkleBranch;
}

uint256 CBlock::CheckMerkleBranch(uint256 hash, const std::vector<uint256>& vMerkleBranch, int nIndex)
{
    if (nIndex == -1)
        return 0;
    BOOST_FOREACH(const uint256& otherside, vMerkleBranch)
    {
        if (nIndex & 1)
            hash = Hash(BEGIN(otherside), END(otherside), BEGIN(hash), END(hash));
        else
            hash = Hash(BEGIN(hash), END(hash), BEGIN(otherside), END(otherside));
        nIndex >>= 1;
    }
    return hash;
}

void CBlock::print() const
{
    printf("CBlock(hash=%s, ver=%d, hashPrevBlock=%s, hashMerkleRoot=%s, nTime=%u, nBits=%08x, nNonce=%u, vtx=%"PRIszu")\n",
        GetHash().ToString().c_str(),
        nVersion,
        hashPrevBlock.ToString().c_str(),
        hashMerkleRoot.ToString().c_str(),
        nTime, nBits, nNonce,
        vtx.size());
    for (unsigned int i = 0; i < vtx.size(); i++)
    {
        printf("  ");
        vtx[i].print();
    }
    printf("  vMerkleTree: ");
    for (unsigned int i = 0; i < vMerkleTree.size(); i++)
        printf("%s ", vMerkleTree[i].ToString().c_str());
    printf("\n");
}