text: // Copyright (c) 2009-2010 Satoshi Nakamoto
  // Copyright (c) 2009-2013 The Narcanisum 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 "uint256.h"
  #include "serialize.h"
  #include "script.h"
  
  #include <stdio.h>
  
  class CTransaction;
  
  /** An outpoint - a combination of a transaction hash and an index n into its vout */
  class COutPoint
  {
  public:
      uint256 hash;
      unsigned int n;
  
      COutPoint() { SetNull(); }
      COutPoint(uint256 hashIn, unsigned int nIn) { hash = hashIn; n = nIn; }
      IMPLEMENT_SERIALIZE( READWRITE(FLATDATA(*this)); )
      void SetNull() { hash = 0; n = (unsigned int) -1; }
      bool IsNull() const { return (hash == 0 && n == (unsigned int) -1); }
  
      friend bool operator<(const COutPoint& a, const COutPoint& b)
      {
          return (a.hash < b.hash || (a.hash == b.hash && 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;
      void print() const;
  };
  
  /** An inpoint - a combination of a transaction and an index n into its vin */
  class CInPoint
  {
  public:
      CTransaction* ptx;
      unsigned int n;
  
      CInPoint() { SetNull(); }
      CInPoint(CTransaction* ptxIn, unsigned int nIn) { ptx = ptxIn; n = nIn; }
      void SetNull() { ptx = NULL; n = (unsigned int) -1; }
      bool IsNull() const { return (ptx == NULL && n == (unsigned int) -1); }
  };
  
  /** 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;
      unsigned int nSequence;
  
      CTxIn()
      {
          nSequence = std::numeric_limits<unsigned int>::max();
      }
  
      explicit CTxIn(COutPoint prevoutIn, CScript scriptSigIn=CScript(), unsigned int nSequenceIn=std::numeric_limits<unsigned int>::max());
      CTxIn(uint256 hashPrevTx, unsigned int nOut, CScript scriptSigIn=CScript(), unsigned int nSequenceIn=std::numeric_limits<unsigned int>::max());
  
      IMPLEMENT_SERIALIZE
      (
          READWRITE(prevout);
          READWRITE(scriptSig);
          READWRITE(nSequence);
      )
  
      bool IsFinal() const
      {
          return (nSequence == std::numeric_limits<unsigned int>::max());
      }
  
      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;
      void print() 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:
      int64 nValue;
      CScript scriptPubKey;
  
      CTxOut()
      {
          SetNull();
      }
  
      CTxOut(int64 nValueIn, CScript scriptPubKeyIn);
  
      IMPLEMENT_SERIALIZE
      (
          READWRITE(nValue);
          READWRITE(scriptPubKey);
      )
  
      void SetNull()
      {
          nValue = -1;
          scriptPubKey.clear();
      }
  
      bool IsNull() const
      {
          return (nValue == -1);
      }
  
      uint256 GetHash() const;
  
      bool IsDust(int64 nMinRelayTxFee) const
      {
          // "Dust" is defined in terms of CTransaction::nMinRelayTxFee,
          // which has units satoshis-per-kilobyte.
          // If you'd pay more than 1/3 in fees
          // to spend something, then we consider it dust.
          // A typical txout is 34 bytes big, and will
          // need a CTxIn of at least 148 bytes to spend,
          // so dust is a txout less than 54 uBTC
          // (5460 satoshis) with default nMinRelayTxFee
          return ((nValue*1000)/(3*((int)GetSerializeSize(SER_DISK,0)+148)) < nMinRelayTxFee);
      }
  
      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;
      void print() const;
  };
  
  
  /** The basic transaction that is broadcasted on the network and contained in
   * blocks.  A transaction can contain multiple inputs and outputs.
   */
  class CTransaction
  {
  public:
      static int64 nMinTxFee;
      static int64 nMinRelayTxFee;
      static const int CURRENT_VERSION=1;
      int nVersion;
      std::vector<CTxIn> vin;
      std::vector<CTxOut> vout;
      unsigned int nLockTime;
  
      CTransaction()
      {
          SetNull();
      }
  
      IMPLEMENT_SERIALIZE
      (
          READWRITE(this->nVersion);
          nVersion = this->nVersion;
          READWRITE(vin);
          READWRITE(vout);
          READWRITE(nLockTime);
      )
  
      void SetNull()
      {
          nVersion = CTransaction::CURRENT_VERSION;
          vin.clear();
          vout.clear();
          nLockTime = 0;
      }
  
      bool IsNull() const
      {
          return (vin.empty() && vout.empty());
      }
  
      uint256 GetHash() const;
      bool IsNewerThan(const CTransaction& old) const;
  
      bool IsCoinBase() const
      {
          return (vin.size() == 1 && vin[0].prevout.IsNull());
      }
  
      friend bool operator==(const CTransaction& a, const CTransaction& b)
      {
          return (a.nVersion  == b.nVersion &&
                  a.vin       == b.vin &&
                  a.vout      == b.vout &&
                  a.nLockTime == b.nLockTime);
      }
  
      friend bool operator!=(const CTransaction& a, const CTransaction& b)
      {
          return !(a == b);
      }
  
  
      std::string ToString() const;
      void print() const;
  };
  
  /** wrapper for CTxOut that provides a more compact serialization */
  class CTxOutCompressor
  {
  private:
      CTxOut &txout;
  
  public:
      static uint64 CompressAmount(uint64 nAmount);
      static uint64 DecompressAmount(uint64 nAmount);
  
      CTxOutCompressor(CTxOut &txoutIn) : txout(txoutIn) { }
  
      IMPLEMENT_SERIALIZE(({
          if (!fRead) {
              uint64 nVal = CompressAmount(txout.nValue);
              READWRITE(VARINT(nVal));
          } else {
              uint64 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;
  
      IMPLEMENT_SERIALIZE(
          READWRITE(vprevout);
      )
  };
  
  
  /** pruned version of CTransaction: only retains metadata and unspent transaction outputs
   *
   * Serialized format:
   * - VARINT(nVersion)
   * - VARINT(nCode)
   * - unspentness bitvector, for vout[2] and further; least significant byte first
   * - the non-spent CTxOuts (via CTxOutCompressor)
   * - VARINT(nHeight)
   *
   * The nCode value consists of:
   * - bit 1: IsCoinBase()
   * - bit 2: vout[0] is not spent
   * - bit 4: vout[1] is not spent
   * - The higher bits encode N, the number of non-zero bytes in the following bitvector.
   *   - In case both bit 2 and bit 4 are unset, they encode N-1, as there must be at
   *     least one non-spent output).
   *
   * Example: 0104835800816115944e077fe7c803cfa57f29b36bf87c1d358bb85e
   *          <><><--------------------------------------------><---->
   *          |  \                  |                             /
   *    version   code             vout[1]                  height
   *
   *    - version = 1
   *    - code = 4 (vout[1] is not spent, and 0 non-zero bytes of bitvector follow)
   *    - unspentness bitvector: as 0 non-zero bytes follow, it has length 0
   *    - vout[1]: 835800816115944e077fe7c803cfa57f29b36bf87c1d35
   *               * 8358: compact amount representation for 60000000000 (600 BTC)
   *               * 00: special txout type pay-to-pubkey-hash
   *               * 816115944e077fe7c803cfa57f29b36bf87c1d35: address uint160
   *    - height = 203998
   *
   *
   * Example: 0109044086ef97d5790061b01caab50f1b8e9c50a5057eb43c2d9563a4eebbd123008c988f1a4a4de2161e0f50aac7f17e7f9555caa486af3b
   *          <><><--><--------------------------------------------------><----------------------------------------------><---->
   *         /  \   \                     |                                                           |                     /
   *  version  code  unspentness       vout[4]                                                     vout[16]           height
   *
   *  - version = 1
   *  - code = 9 (coinbase, neither vout[0] or vout[1] are unspent,
   *                2 (1, +1 because both bit 2 and bit 4 are unset) non-zero bitvector bytes follow)
   *  - unspentness bitvector: bits 2 (0x04) and 14 (0x4000) are set, so vout[2+2] and vout[14+2] are unspent
   *  - vout[4]: 86ef97d5790061b01caab50f1b8e9c50a5057eb43c2d9563a4ee
   *             * 86ef97d579: compact amount representation for 234925952 (2.35 BTC)
   *             * 00: special txout type pay-to-pubkey-hash
   *             * 61b01caab50f1b8e9c50a5057eb43c2d9563a4ee: address uint160
   *  - vout[16]: bbd123008c988f1a4a4de2161e0f50aac7f17e7f9555caa4
   *              * bbd123: compact amount representation for 110397 (0.001 BTC)
   *              * 00: special txout type pay-to-pubkey-hash
   *              * 8c988f1a4a4de2161e0f50aac7f17e7f9555caa4: address uint160
   *  - height = 120891
   */
  class CCoins
  {
  public:
      // whether transaction is a coinbase
      bool fCoinBase;
  
      // unspent transaction outputs; spent outputs are .IsNull(); spent outputs at the end of the array are dropped
      std::vector<CTxOut> vout;
  
      // at which height this transaction was included in the active block chain
      int nHeight;
  
      // version of the CTransaction; accesses to this value should probably check for nHeight as well,
      // as new tx version will probably only be introduced at certain heights
      int nVersion;
  
      // construct a CCoins from a CTransaction, at a given height
      CCoins(const CTransaction &tx, int nHeightIn) : fCoinBase(tx.IsCoinBase()), vout(tx.vout), nHeight(nHeightIn), nVersion(tx.nVersion) { }
  
      // empty constructor
      CCoins() : fCoinBase(false), vout(0), nHeight(0), nVersion(0) { }
  
      // remove spent outputs at the end of vout
      void Cleanup() {
          while (vout.size() > 0 && vout.back().IsNull())
              vout.pop_back();
          if (vout.empty())
              std::vector<CTxOut>().swap(vout);
      }
  
      void swap(CCoins &to) {
          std::swap(to.fCoinBase, fCoinBase);
          to.vout.swap(vout);
          std::swap(to.nHeight, nHeight);
          std::swap(to.nVersion, nVersion);
      }
  
      // equality test
      friend bool operator==(const CCoins &a, const CCoins &b) {
           return a.fCoinBase == b.fCoinBase &&
                  a.nHeight == b.nHeight &&
                  a.nVersion == b.nVersion &&
                  a.vout == b.vout;
      }
      friend bool operator!=(const CCoins &a, const CCoins &b) {
          return !(a == b);
      }
  
      void CalcMaskSize(unsigned int &nBytes, unsigned int &nNonzeroBytes) const;
  
      bool IsCoinBase() const {
          return fCoinBase;
      }
  
      unsigned int GetSerializeSize(int nType, int nVersion) const {
          unsigned int nSize = 0;
          unsigned int nMaskSize = 0, nMaskCode = 0;
          CalcMaskSize(nMaskSize, nMaskCode);
          bool fFirst = vout.size() > 0 && !vout[0].IsNull();
          bool fSecond = vout.size() > 1 && !vout[1].IsNull();
          assert(fFirst || fSecond || nMaskCode);
          unsigned int nCode = 8*(nMaskCode - (fFirst || fSecond ? 0 : 1)) + (fCoinBase ? 1 : 0) + (fFirst ? 2 : 0) + (fSecond ? 4 : 0);
          // version
          nSize += ::GetSerializeSize(VARINT(this->nVersion), nType, nVersion);
          // size of header code
          nSize += ::GetSerializeSize(VARINT(nCode), nType, nVersion);
          // spentness bitmask
          nSize += nMaskSize;
          // txouts themself
          for (unsigned int i = 0; i < vout.size(); i++)
              if (!vout[i].IsNull())
                  nSize += ::GetSerializeSize(CTxOutCompressor(REF(vout[i])), nType, nVersion);
          // height
          nSize += ::GetSerializeSize(VARINT(nHeight), nType, nVersion);
          return nSize;
      }
  
      template<typename Stream>
      void Serialize(Stream &s, int nType, int nVersion) const {
          unsigned int nMaskSize = 0, nMaskCode = 0;
          CalcMaskSize(nMaskSize, nMaskCode);
          bool fFirst = vout.size() > 0 && !vout[0].IsNull();
          bool fSecond = vout.size() > 1 && !vout[1].IsNull();
          assert(fFirst || fSecond || nMaskCode);
          unsigned int nCode = 8*(nMaskCode - (fFirst || fSecond ? 0 : 1)) + (fCoinBase ? 1 : 0) + (fFirst ? 2 : 0) + (fSecond ? 4 : 0);
          // version
          ::Serialize(s, VARINT(this->nVersion), nType, nVersion);
          // header code
          ::Serialize(s, VARINT(nCode), nType, nVersion);
          // spentness bitmask
          for (unsigned int b = 0; b<nMaskSize; b++) {
              unsigned char chAvail = 0;
              for (unsigned int i = 0; i < 8 && 2+b*8+i < vout.size(); i++)
                  if (!vout[2+b*8+i].IsNull())
                      chAvail |= (1 << i);
              ::Serialize(s, chAvail, nType, nVersion);
          }
          // txouts themself
          for (unsigned int i = 0; i < vout.size(); i++) {
              if (!vout[i].IsNull())
                  ::Serialize(s, CTxOutCompressor(REF(vout[i])), nType, nVersion);
          }
          // coinbase height
          ::Serialize(s, VARINT(nHeight), nType, nVersion);
      }
  
      template<typename Stream>
      void Unserialize(Stream &s, int nType, int nVersion) {
          unsigned int nCode = 0;
          // version
          ::Unserialize(s, VARINT(this->nVersion), nType, nVersion);
          // header code
          ::Unserialize(s, VARINT(nCode), nType, nVersion);
          fCoinBase = nCode & 1;
          std::vector<bool> vAvail(2, false);
          vAvail[0] = nCode & 2;
          vAvail[1] = nCode & 4;
          unsigned int nMaskCode = (nCode / 8) + ((nCode & 6) != 0 ? 0 : 1);
          // spentness bitmask
          while (nMaskCode > 0) {
              unsigned char chAvail = 0;
              ::Unserialize(s, chAvail, nType, nVersion);
              for (unsigned int p = 0; p < 8; p++) {
                  bool f = (chAvail & (1 << p)) != 0;
                  vAvail.push_back(f);
              }
              if (chAvail != 0)
                  nMaskCode--;
          }
          // txouts themself
          vout.assign(vAvail.size(), CTxOut());
          for (unsigned int i = 0; i < vAvail.size(); i++) {
              if (vAvail[i])
                  ::Unserialize(s, REF(CTxOutCompressor(vout[i])), nType, nVersion);
          }
          // coinbase height
          ::Unserialize(s, VARINT(nHeight), nType, nVersion);
          Cleanup();
      }
  
      // mark an outpoint spent, and construct undo information
      bool Spend(const COutPoint &out, CTxInUndo &undo);
  
      // mark a vout spent
      bool Spend(int nPos);
  
      // check whether a particular output is still available
      bool IsAvailable(unsigned int nPos) const {
          return (nPos < vout.size() && !vout[nPos].IsNull());
      }
  
      // check whether the entire CCoins is spent
      // note that only !IsPruned() CCoins can be serialized
      bool IsPruned() const {
          BOOST_FOREACH(const CTxOut &out, vout)
              if (!out.IsNull())
                  return false;
          return true;
      }
  };
  
  
  /** 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 int CURRENT_VERSION=2;
      int nVersion;
      uint256 hashPrevBlock;
      uint256 hashMerkleRoot;
      unsigned int nTime;
      unsigned int nBits;
      unsigned int nNonce;
  
      CBlockHeader()
      {
          SetNull();
      }
  
      IMPLEMENT_SERIALIZE
      (
          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 GetBlockTime() const
      {
          return (int64)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;
      }
  
      IMPLEMENT_SERIALIZE
      (
          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;
      }
  
      uint256 BuildMerkleTree() const;
  
      const uint256 &GetTxHash(unsigned int nIndex) const {
          assert(vMerkleTree.size() > 0); // BuildMerkleTree must have been called first
          assert(nIndex < vtx.size());
          return vMerkleTree[nIndex];
      }
  
      std::vector<uint256> GetMerkleBranch(int nIndex) const;
      static uint256 CheckMerkleBranch(uint256 hash, const std::vector<uint256>& vMerkleBranch, int nIndex);
      void print() const;
  };
  
  #endif
  