src/amount.h

   1 // Copyright (c) 2009-2010 Satoshi Nakamoto
   2 // Copyright (c) 2009-2014 The Bitcoin Core developers
   3 // Distributed under the MIT software license, see the accompanying
   4 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
   5
   6 #ifndef BITCOIN_AMOUNT_H
   7 #define BITCOIN_AMOUNT_H
   8
   9 #include "serialize.h"
  10
  11 #include <stdlib.h>
  12 #include <string>
  13
  14 typedef int64_t CAmount;
  15
  16 static const CAmount COIN = 100000000;
  17 static const CAmount CENT = 1000000;
  18
  19 extern const std::string CURRENCY_UNIT;
  20
  21 /** No amount larger than this (in satoshi) is valid.
  22  *
  23  * Note that this constant is *not* the total money supply, which in Bitcoin
  24  * currently happens to be less than 21,000,000 BTC for various reasons, but
  25  * rather a sanity check. As this sanity check is used by consensus-critical
  26  * validation code, the exact value of the MAX_MONEY constant is consensus
  27  * critical; in unusual circumstances like a(nother) overflow bug that allowed
  28  * for the creation of coins out of thin air modification could lead to a fork.
  29  * */
  30 static const CAmount MAX_MONEY = 21000000 * COIN;
  31 inline bool MoneyRange(const CAmount& nValue) { return (nValue >= 0 && nValue <= MAX_MONEY); }
  32
  33 /** Type-safe wrapper class to for fee rates
  34  * (how much to pay based on transaction size)
  35  */
  36 class CFeeRate
  37 {
  38 private:
  39     CAmount nSatoshisPerK; // unit is satoshis-per-1,000-bytes
  40 public:
  41     CFeeRate() : nSatoshisPerK(0) { }
  42     explicit CFeeRate(const CAmount& _nSatoshisPerK): nSatoshisPerK(_nSatoshisPerK) { }
  43     CFeeRate(const CAmount& nFeePaid, size_t nSize);
  44     CFeeRate(const CFeeRate& other) { nSatoshisPerK = other.nSatoshisPerK; }
  45
  46     CAmount GetFee(size_t size) const; // unit returned is satoshis
  47     CAmount GetFeePerK() const { return GetFee(1000); } // satoshis-per-1000-bytes
  48
  49     friend bool operator<(const CFeeRate& a, const CFeeRate& b) { return a.nSatoshisPerK < b.nSatoshisPerK; }
  50     friend bool operator>(const CFeeRate& a, const CFeeRate& b) { return a.nSatoshisPerK > b.nSatoshisPerK; }
  51     friend bool operator==(const CFeeRate& a, const CFeeRate& b) { return a.nSatoshisPerK == b.nSatoshisPerK; }
  52     friend bool operator<=(const CFeeRate& a, const CFeeRate& b) { return a.nSatoshisPerK <= b.nSatoshisPerK; }
  53     friend bool operator>=(const CFeeRate& a, const CFeeRate& b) { return a.nSatoshisPerK >= b.nSatoshisPerK; }
  54     std::string ToString() const;
  55
  56     ADD_SERIALIZE_METHODS;
  57
  58     template <typename Stream, typename Operation>
  59     inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion) {
  60         READWRITE(nSatoshisPerK);
  61     }
  62 };
  63
  64 #endif //  BITCOIN_AMOUNT_H