lbrycrd/src/uint256.h
2014-06-28 18:02:42 +02:00

327 lines
9.3 KiB
C++

// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2014 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_UINT256_H
#define BITCOIN_UINT256_H
#include <assert.h>
#include <stdexcept>
#include <stdint.h>
#include <string>
#include <vector>
class uint_error : public std::runtime_error {
public:
explicit uint_error(const std::string& str) : std::runtime_error(str) {}
};
/** Template base class for unsigned big integers. */
template<unsigned int BITS>
class base_uint
{
private:
enum { WIDTH=BITS/32 };
uint32_t pn[WIDTH];
public:
base_uint()
{
for (int i = 0; i < WIDTH; i++)
pn[i] = 0;
}
base_uint(const base_uint& b)
{
for (int i = 0; i < WIDTH; i++)
pn[i] = b.pn[i];
}
base_uint& operator=(const base_uint& b)
{
for (int i = 0; i < WIDTH; i++)
pn[i] = b.pn[i];
return *this;
}
base_uint(uint64_t b)
{
pn[0] = (unsigned int)b;
pn[1] = (unsigned int)(b >> 32);
for (int i = 2; i < WIDTH; i++)
pn[i] = 0;
}
explicit base_uint(const std::string& str);
explicit base_uint(const std::vector<unsigned char>& vch);
bool operator!() const
{
for (int i = 0; i < WIDTH; i++)
if (pn[i] != 0)
return false;
return true;
}
const base_uint operator~() const
{
base_uint ret;
for (int i = 0; i < WIDTH; i++)
ret.pn[i] = ~pn[i];
return ret;
}
const base_uint operator-() const
{
base_uint ret;
for (int i = 0; i < WIDTH; i++)
ret.pn[i] = ~pn[i];
ret++;
return ret;
}
double getdouble() const;
base_uint& operator=(uint64_t b)
{
pn[0] = (unsigned int)b;
pn[1] = (unsigned int)(b >> 32);
for (int i = 2; i < WIDTH; i++)
pn[i] = 0;
return *this;
}
base_uint& operator^=(const base_uint& b)
{
for (int i = 0; i < WIDTH; i++)
pn[i] ^= b.pn[i];
return *this;
}
base_uint& operator&=(const base_uint& b)
{
for (int i = 0; i < WIDTH; i++)
pn[i] &= b.pn[i];
return *this;
}
base_uint& operator|=(const base_uint& b)
{
for (int i = 0; i < WIDTH; i++)
pn[i] |= b.pn[i];
return *this;
}
base_uint& operator^=(uint64_t b)
{
pn[0] ^= (unsigned int)b;
pn[1] ^= (unsigned int)(b >> 32);
return *this;
}
base_uint& operator|=(uint64_t b)
{
pn[0] |= (unsigned int)b;
pn[1] |= (unsigned int)(b >> 32);
return *this;
}
base_uint& operator<<=(unsigned int shift);
base_uint& operator>>=(unsigned int shift);
base_uint& operator+=(const base_uint& b)
{
uint64_t carry = 0;
for (int i = 0; i < WIDTH; i++)
{
uint64_t n = carry + pn[i] + b.pn[i];
pn[i] = n & 0xffffffff;
carry = n >> 32;
}
return *this;
}
base_uint& operator-=(const base_uint& b)
{
*this += -b;
return *this;
}
base_uint& operator+=(uint64_t b64)
{
base_uint b;
b = b64;
*this += b;
return *this;
}
base_uint& operator-=(uint64_t b64)
{
base_uint b;
b = b64;
*this += -b;
return *this;
}
base_uint& operator*=(uint32_t b32);
base_uint& operator*=(const base_uint& b);
base_uint& operator/=(const base_uint& b);
base_uint& operator++()
{
// prefix operator
int i = 0;
while (++pn[i] == 0 && i < WIDTH-1)
i++;
return *this;
}
const base_uint operator++(int)
{
// postfix operator
const base_uint ret = *this;
++(*this);
return ret;
}
base_uint& operator--()
{
// prefix operator
int i = 0;
while (--pn[i] == (uint32_t)-1 && i < WIDTH-1)
i++;
return *this;
}
const base_uint operator--(int)
{
// postfix operator
const base_uint ret = *this;
--(*this);
return ret;
}
int CompareTo(const base_uint& b) const;
bool EqualTo(uint64_t b) const;
friend inline const base_uint operator+(const base_uint& a, const base_uint& b) { return base_uint(a) += b; }
friend inline const base_uint operator-(const base_uint& a, const base_uint& b) { return base_uint(a) -= b; }
friend inline const base_uint operator*(const base_uint& a, const base_uint& b) { return base_uint(a) *= b; }
friend inline const base_uint operator/(const base_uint& a, const base_uint& b) { return base_uint(a) /= b; }
friend inline const base_uint operator|(const base_uint& a, const base_uint& b) { return base_uint(a) |= b; }
friend inline const base_uint operator&(const base_uint& a, const base_uint& b) { return base_uint(a) &= b; }
friend inline const base_uint operator^(const base_uint& a, const base_uint& b) { return base_uint(a) ^= b; }
friend inline const base_uint operator>>(const base_uint& a, int shift) { return base_uint(a) >>= shift; }
friend inline const base_uint operator<<(const base_uint& a, int shift) { return base_uint(a) <<= shift; }
friend inline const base_uint operator*(const base_uint& a, uint32_t b) { return base_uint(a) *= b; }
friend inline bool operator==(const base_uint& a, const base_uint& b) { return a.CompareTo(b) == 0; }
friend inline bool operator!=(const base_uint& a, const base_uint& b) { return a.CompareTo(b) != 0; }
friend inline bool operator>(const base_uint& a, const base_uint& b) { return a.CompareTo(b) > 0; }
friend inline bool operator<(const base_uint& a, const base_uint& b) { return a.CompareTo(b) < 0; }
friend inline bool operator>=(const base_uint& a, const base_uint& b) { return a.CompareTo(b) >= 0; }
friend inline bool operator<=(const base_uint& a, const base_uint& b) { return a.CompareTo(b) <= 0; }
friend inline bool operator==(const base_uint& a, uint64_t b) { return a.EqualTo(b); }
friend inline bool operator!=(const base_uint& a, uint64_t b) { return !a.EqualTo(b); }
std::string GetHex() const;
void SetHex(const char* psz);
void SetHex(const std::string& str);
std::string ToString() const;
unsigned char* begin()
{
return (unsigned char*)&pn[0];
}
unsigned char* end()
{
return (unsigned char*)&pn[WIDTH];
}
const unsigned char* begin() const
{
return (unsigned char*)&pn[0];
}
const unsigned char* end() const
{
return (unsigned char*)&pn[WIDTH];
}
unsigned int size() const
{
return sizeof(pn);
}
// Returns the position of the highest bit set plus one, or zero if the
// value is zero.
unsigned int bits() const;
uint64_t GetLow64() const
{
assert(WIDTH >= 2);
return pn[0] | (uint64_t)pn[1] << 32;
}
unsigned int GetSerializeSize(int nType, int nVersion) const
{
return sizeof(pn);
}
template<typename Stream>
void Serialize(Stream& s, int nType, int nVersion) const
{
s.write((char*)pn, sizeof(pn));
}
template<typename Stream>
void Unserialize(Stream& s, int nType, int nVersion)
{
s.read((char*)pn, sizeof(pn));
}
};
/** 160-bit unsigned big integer. */
class uint160 : public base_uint<160> {
public:
uint160() {}
uint160(const base_uint<160>& b) : base_uint<160>(b) {}
uint160(uint64_t b) : base_uint<160>(b) {}
explicit uint160(const std::string& str) : base_uint<160>(str) {}
explicit uint160(const std::vector<unsigned char>& vch) : base_uint<160>(vch) {}
};
/** 256-bit unsigned big integer. */
class uint256 : public base_uint<256> {
public:
uint256() {}
uint256(const base_uint<256>& b) : base_uint<256>(b) {}
uint256(uint64_t b) : base_uint<256>(b) {}
explicit uint256(const std::string& str) : base_uint<256>(str) {}
explicit uint256(const std::vector<unsigned char>& vch) : base_uint<256>(vch) {}
// The "compact" format is a representation of a whole
// number N using an unsigned 32bit number similar to a
// floating point format.
// The most significant 8 bits are the unsigned exponent of base 256.
// This exponent can be thought of as "number of bytes of N".
// The lower 23 bits are the mantissa.
// Bit number 24 (0x800000) represents the sign of N.
// N = (-1^sign) * mantissa * 256^(exponent-3)
//
// Satoshi's original implementation used BN_bn2mpi() and BN_mpi2bn().
// MPI uses the most significant bit of the first byte as sign.
// Thus 0x1234560000 is compact (0x05123456)
// and 0xc0de000000 is compact (0x0600c0de)
// (0x05c0de00) would be -0x40de000000
//
// Bitcoin only uses this "compact" format for encoding difficulty
// targets, which are unsigned 256bit quantities. Thus, all the
// complexities of the sign bit and using base 256 are probably an
// implementation accident.
uint256& SetCompact(uint32_t nCompact, bool *pfNegative = NULL, bool *pfOverflow = NULL);
uint32_t GetCompact(bool fNegative = false) const;
};
#endif