path: root/src/core.h

// 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.

#ifndef BITCOIN_CORE_H
#define BITCOIN_CORE_H

#include "core/transaction.h"
#include "script/compressor.h"
#include "serialize.h"
#include "uint256.h"

/** wrapper for CTxOut that provides a more compact serialization */
class CTxOutCompressor
{
private:
    CTxOut &txout;

public:
    static uint64_t CompressAmount(uint64_t nAmount);
    static uint64_t DecompressAmount(uint64_t nAmount);

    CTxOutCompressor(CTxOut &txoutIn) : txout(txoutIn) { }

    ADD_SERIALIZE_METHODS;

    template <typename Stream, typename Operation>
    inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion) {
        if (!ser_action.ForRead()) {
            uint64_t nVal = CompressAmount(txout.nValue);
            READWRITE(VARINT(nVal));
        } else {
            uint64_t nVal = 0;
            READWRITE(VARINT(nVal));
            txout.nValue = DecompressAmount(nVal);
        }
        CScriptCompressor cscript(REF(txout.scriptPubKey));
        READWRITE(cscript);
    }
};

/** Undo information for a CTxIn
 *
 *  Contains the prevout's CTxOut being spent, and if this was the
 *  last output of the affected transaction, its metadata as well
 *  (coinbase or not, height, transaction version)
 */
class CTxInUndo
{
public:
    CTxOut txout;         // the txout data before being spent
    bool fCoinBase;       // if the outpoint was the last unspent: whether it belonged to a coinbase
    unsigned int nHeight; // if the outpoint was the last unspent: its height
    int nVersion;         // if the outpoint was the last unspent: its version

    CTxInUndo() : txout(), fCoinBase(false), nHeight(0), nVersion(0) {}
    CTxInUndo(const CTxOut &txoutIn, bool fCoinBaseIn = false, unsigned int nHeightIn = 0, int nVersionIn = 0) : txout(txoutIn), fCoinBase(fCoinBaseIn), nHeight(nHeightIn), nVersion(nVersionIn) { }

    unsigned int GetSerializeSize(int nType, int nVersion) const {
        return ::GetSerializeSize(VARINT(nHeight*2+(fCoinBase ? 1 : 0)), nType, nVersion) +
               (nHeight > 0 ? ::GetSerializeSize(VARINT(this->nVersion), nType, nVersion) : 0) +
               ::GetSerializeSize(CTxOutCompressor(REF(txout)), nType, nVersion);
    }

    template<typename Stream>
    void Serialize(Stream &s, int nType, int nVersion) const {
        ::Serialize(s, VARINT(nHeight*2+(fCoinBase ? 1 : 0)), nType, nVersion);
        if (nHeight > 0)
            ::Serialize(s, VARINT(this->nVersion), nType, nVersion);
        ::Serialize(s, CTxOutCompressor(REF(txout)), nType, nVersion);
    }

    template<typename Stream>
    void Unserialize(Stream &s, int nType, int nVersion) {
        unsigned int nCode = 0;
        ::Unserialize(s, VARINT(nCode), nType, nVersion);
        nHeight = nCode / 2;
        fCoinBase = nCode & 1;
        if (nHeight > 0)
            ::Unserialize(s, VARINT(this->nVersion), nType, nVersion);
        ::Unserialize(s, REF(CTxOutCompressor(REF(txout))), nType, nVersion);
    }
};

/** Undo information for a CTransaction */
class CTxUndo
{
public:
    // undo information for all txins
    std::vector<CTxInUndo> vprevout;

    ADD_SERIALIZE_METHODS;

    template <typename Stream, typename Operation>
    inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion) {
        READWRITE(vprevout);
    }
};


/** Nodes collect new transactions into a block, hash them into a hash tree,
 * and scan through nonce values to make the block's hash satisfy proof-of-work
 * requirements.  When they solve the proof-of-work, they broadcast the block
 * to everyone and the block is added to the block chain.  The first transaction
 * in the block is a special one that creates a new coin owned by the creator
 * of the block.
 */
class CBlockHeader
{
public:
    // header
    static const int32_t CURRENT_VERSION=2;
    int32_t nVersion;
    uint256 hashPrevBlock;
    uint256 hashMerkleRoot;
    uint32_t nTime;
    uint32_t nBits;
    uint32_t nNonce;

    CBlockHeader()
    {
        SetNull();
    }

    ADD_SERIALIZE_METHODS;

    template <typename Stream, typename Operation>
    inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion) {
        READWRITE(this->nVersion);
        nVersion = this->nVersion;
        READWRITE(hashPrevBlock);
        READWRITE(hashMerkleRoot);
        READWRITE(nTime);
        READWRITE(nBits);
        READWRITE(nNonce);
    }

    void SetNull()
    {
        nVersion = CBlockHeader::CURRENT_VERSION;
        hashPrevBlock = 0;
        hashMerkleRoot = 0;
        nTime = 0;
        nBits = 0;
        nNonce = 0;
    }

    bool IsNull() const
    {
        return (nBits == 0);
    }

    uint256 GetHash() const;

    int64_t GetBlockTime() const
    {
        return (int64_t)nTime;
    }
};


class CBlock : public CBlockHeader
{
public:
    // network and disk
    std::vector<CTransaction> vtx;

    // memory only
    mutable std::vector<uint256> vMerkleTree;

    CBlock()
    {
        SetNull();
    }

    CBlock(const CBlockHeader &header)
    {
        SetNull();
        *((CBlockHeader*)this) = header;
    }

    ADD_SERIALIZE_METHODS;

    template <typename Stream, typename Operation>
    inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion) {
        READWRITE(*(CBlockHeader*)this);
        READWRITE(vtx);
    }

    void SetNull()
    {
        CBlockHeader::SetNull();
        vtx.clear();
        vMerkleTree.clear();
    }

    CBlockHeader GetBlockHeader() const
    {
        CBlockHeader block;
        block.nVersion       = nVersion;
        block.hashPrevBlock  = hashPrevBlock;
        block.hashMerkleRoot = hashMerkleRoot;
        block.nTime          = nTime;
        block.nBits          = nBits;
        block.nNonce         = nNonce;
        return block;
    }

    // Build the in-memory merkle tree for this block and return the merkle root.
    // If non-NULL, *mutated is set to whether mutation was detected in the merkle
    // tree (a duplication of transactions in the block leading to an identical
    // merkle root).
    uint256 BuildMerkleTree(bool* mutated = NULL) const;

    std::vector<uint256> GetMerkleBranch(int nIndex) const;
    static uint256 CheckMerkleBranch(uint256 hash, const std::vector<uint256>& vMerkleBranch, int nIndex);
    std::string ToString() const;
};


/** Describes a place in the block chain to another node such that if the
 * other node doesn't have the same branch, it can find a recent common trunk.
 * The further back it is, the further before the fork it may be.
 */
struct CBlockLocator
{
    std::vector<uint256> vHave;

    CBlockLocator() {}

    CBlockLocator(const std::vector<uint256>& vHaveIn)
    {
        vHave = vHaveIn;
    }

    ADD_SERIALIZE_METHODS;

    template <typename Stream, typename Operation>
    inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion) {
        if (!(nType & SER_GETHASH))
            READWRITE(nVersion);
        READWRITE(vHave);
    }

    void SetNull()
    {
        vHave.clear();
    }

    bool IsNull()
    {
        return vHave.empty();
    }
};

#endif // BITCOIN_CORE_H