Bitcoin Core  22.99.0
P2P Digital Currency
scriptnum10.h
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1 // Copyright (c) 2009-2010 Satoshi Nakamoto
2 // Copyright (c) 2009-2020 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_TEST_SCRIPTNUM10_H
7 #define BITCOIN_TEST_SCRIPTNUM10_H
8 
9 #include <assert.h>
10 #include <limits>
11 #include <stdexcept>
12 #include <stdint.h>
13 #include <string>
14 #include <vector>
15 
16 class scriptnum10_error : public std::runtime_error
17 {
18 public:
19  explicit scriptnum10_error(const std::string& str) : std::runtime_error(str) {}
20 };
21 
23 {
27 public:
28 
29  explicit CScriptNum10(const int64_t& n)
30  {
31  m_value = n;
32  }
33 
34  static const size_t nDefaultMaxNumSize = 4;
35 
36  explicit CScriptNum10(const std::vector<unsigned char>& vch, bool fRequireMinimal,
37  const size_t nMaxNumSize = nDefaultMaxNumSize)
38  {
39  if (vch.size() > nMaxNumSize) {
40  throw scriptnum10_error("script number overflow");
41  }
42  if (fRequireMinimal && vch.size() > 0) {
43  // Check that the number is encoded with the minimum possible
44  // number of bytes.
45  //
46  // If the most-significant-byte - excluding the sign bit - is zero
47  // then we're not minimal. Note how this test also rejects the
48  // negative-zero encoding, 0x80.
49  if ((vch.back() & 0x7f) == 0) {
50  // One exception: if there's more than one byte and the most
51  // significant bit of the second-most-significant-byte is set
52  // it would conflict with the sign bit. An example of this case
53  // is +-255, which encode to 0xff00 and 0xff80 respectively.
54  // (big-endian).
55  if (vch.size() <= 1 || (vch[vch.size() - 2] & 0x80) == 0) {
56  throw scriptnum10_error("non-minimally encoded script number");
57  }
58  }
59  }
60  m_value = set_vch(vch);
61  }
62 
63  inline bool operator==(const int64_t& rhs) const { return m_value == rhs; }
64  inline bool operator!=(const int64_t& rhs) const { return m_value != rhs; }
65  inline bool operator<=(const int64_t& rhs) const { return m_value <= rhs; }
66  inline bool operator< (const int64_t& rhs) const { return m_value < rhs; }
67  inline bool operator>=(const int64_t& rhs) const { return m_value >= rhs; }
68  inline bool operator> (const int64_t& rhs) const { return m_value > rhs; }
69 
70  inline bool operator==(const CScriptNum10& rhs) const { return operator==(rhs.m_value); }
71  inline bool operator!=(const CScriptNum10& rhs) const { return operator!=(rhs.m_value); }
72  inline bool operator<=(const CScriptNum10& rhs) const { return operator<=(rhs.m_value); }
73  inline bool operator< (const CScriptNum10& rhs) const { return operator< (rhs.m_value); }
74  inline bool operator>=(const CScriptNum10& rhs) const { return operator>=(rhs.m_value); }
75  inline bool operator> (const CScriptNum10& rhs) const { return operator> (rhs.m_value); }
76 
77  inline CScriptNum10 operator+( const int64_t& rhs) const { return CScriptNum10(m_value + rhs);}
78  inline CScriptNum10 operator-( const int64_t& rhs) const { return CScriptNum10(m_value - rhs);}
79  inline CScriptNum10 operator+( const CScriptNum10& rhs) const { return operator+(rhs.m_value); }
80  inline CScriptNum10 operator-( const CScriptNum10& rhs) const { return operator-(rhs.m_value); }
81 
82  inline CScriptNum10& operator+=( const CScriptNum10& rhs) { return operator+=(rhs.m_value); }
83  inline CScriptNum10& operator-=( const CScriptNum10& rhs) { return operator-=(rhs.m_value); }
84 
85  inline CScriptNum10 operator-() const
86  {
87  assert(m_value != std::numeric_limits<int64_t>::min());
88  return CScriptNum10(-m_value);
89  }
90 
91  inline CScriptNum10& operator=( const int64_t& rhs)
92  {
93  m_value = rhs;
94  return *this;
95  }
96 
97  inline CScriptNum10& operator+=( const int64_t& rhs)
98  {
99  assert(rhs == 0 || (rhs > 0 && m_value <= std::numeric_limits<int64_t>::max() - rhs) ||
100  (rhs < 0 && m_value >= std::numeric_limits<int64_t>::min() - rhs));
101  m_value += rhs;
102  return *this;
103  }
104 
105  inline CScriptNum10& operator-=( const int64_t& rhs)
106  {
107  assert(rhs == 0 || (rhs > 0 && m_value >= std::numeric_limits<int64_t>::min() + rhs) ||
108  (rhs < 0 && m_value <= std::numeric_limits<int64_t>::max() + rhs));
109  m_value -= rhs;
110  return *this;
111  }
112 
113  int getint() const
114  {
115  if (m_value > std::numeric_limits<int>::max())
116  return std::numeric_limits<int>::max();
117  else if (m_value < std::numeric_limits<int>::min())
118  return std::numeric_limits<int>::min();
119  return m_value;
120  }
121 
122  std::vector<unsigned char> getvch() const
123  {
124  return serialize(m_value);
125  }
126 
127  static std::vector<unsigned char> serialize(const int64_t& value)
128  {
129  if(value == 0)
130  return std::vector<unsigned char>();
131 
132  std::vector<unsigned char> result;
133  const bool neg = value < 0;
134  uint64_t absvalue = neg ? -value : value;
135 
136  while(absvalue)
137  {
138  result.push_back(absvalue & 0xff);
139  absvalue >>= 8;
140  }
141 
142 // - If the most significant byte is >= 0x80 and the value is positive, push a
143 // new zero-byte to make the significant byte < 0x80 again.
144 
145 // - If the most significant byte is >= 0x80 and the value is negative, push a
146 // new 0x80 byte that will be popped off when converting to an integral.
147 
148 // - If the most significant byte is < 0x80 and the value is negative, add
149 // 0x80 to it, since it will be subtracted and interpreted as a negative when
150 // converting to an integral.
151 
152  if (result.back() & 0x80)
153  result.push_back(neg ? 0x80 : 0);
154  else if (neg)
155  result.back() |= 0x80;
156 
157  return result;
158  }
159 
160 private:
161  static int64_t set_vch(const std::vector<unsigned char>& vch)
162  {
163  if (vch.empty())
164  return 0;
165 
166  int64_t result = 0;
167  for (size_t i = 0; i != vch.size(); ++i)
168  result |= static_cast<int64_t>(vch[i]) << 8*i;
169 
170  // If the input vector's most significant byte is 0x80, remove it from
171  // the result's msb and return a negative.
172  if (vch.back() & 0x80)
173  return -((int64_t)(result & ~(0x80ULL << (8 * (vch.size() - 1)))));
174 
175  return result;
176  }
177 
178  int64_t m_value;
179 };
180 
181 
182 #endif // BITCOIN_TEST_BIGNUM_H
CScriptNum10::operator=
CScriptNum10 & operator=(const int64_t &rhs)
Definition: scriptnum10.h:91
CScriptNum10::operator<
bool operator<(const int64_t &rhs) const
Definition: scriptnum10.h:66
assert
assert(!tx.IsCoinBase())
CScriptNum10::operator-=
CScriptNum10 & operator-=(const int64_t &rhs)
Definition: scriptnum10.h:105
CScriptNum10::operator-
CScriptNum10 operator-(const CScriptNum10 &rhs) const
Definition: scriptnum10.h:80
CScriptNum10::CScriptNum10
CScriptNum10(const std::vector< unsigned char > &vch, bool fRequireMinimal, const size_t nMaxNumSize=nDefaultMaxNumSize)
Definition: scriptnum10.h:36
CScriptNum10::operator>=
bool operator>=(const int64_t &rhs) const
Definition: scriptnum10.h:67
CScriptNum10::operator<=
bool operator<=(const CScriptNum10 &rhs) const
Definition: scriptnum10.h:72
scriptnum10_error::scriptnum10_error
scriptnum10_error(const std::string &str)
Definition: scriptnum10.h:19
CScriptNum10::operator+=
CScriptNum10 & operator+=(const CScriptNum10 &rhs)
Definition: scriptnum10.h:82
CScriptNum10::operator-
CScriptNum10 operator-() const
Definition: scriptnum10.h:85
CScriptNum10::nDefaultMaxNumSize
static const size_t nDefaultMaxNumSize
Definition: scriptnum10.h:34
CScriptNum10::operator==
bool operator==(const CScriptNum10 &rhs) const
Definition: scriptnum10.h:70
CScriptNum10::operator+
CScriptNum10 operator+(const int64_t &rhs) const
Definition: scriptnum10.h:77
CScriptNum10::operator>
bool operator>(const int64_t &rhs) const
Definition: scriptnum10.h:68
CScriptNum10::operator+=
CScriptNum10 & operator+=(const int64_t &rhs)
Definition: scriptnum10.h:97
CScriptNum10::operator-
CScriptNum10 operator-(const int64_t &rhs) const
Definition: scriptnum10.h:78
CScriptNum10::operator+
CScriptNum10 operator+(const CScriptNum10 &rhs) const
Definition: scriptnum10.h:79
CScriptNum10::operator==
bool operator==(const int64_t &rhs) const
Definition: scriptnum10.h:63
CScriptNum10::serialize
static std::vector< unsigned char > serialize(const int64_t &value)
Definition: scriptnum10.h:127
CScriptNum10::CScriptNum10
CScriptNum10(const int64_t &n)
The ScriptNum implementation from Bitcoin Core 0.10.0, for cross-comparison.
Definition: scriptnum10.h:29
CScriptNum10::m_value
int64_t m_value
Definition: scriptnum10.h:178
CScriptNum10::operator>=
bool operator>=(const CScriptNum10 &rhs) const
Definition: scriptnum10.h:74
CScriptNum10::getint
int getint() const
Definition: scriptnum10.h:113
scriptnum10_error
Definition: scriptnum10.h:16
CScriptNum10::operator<=
bool operator<=(const int64_t &rhs) const
Definition: scriptnum10.h:65
CScriptNum10::operator!=
bool operator!=(const int64_t &rhs) const
Definition: scriptnum10.h:64
CScriptNum10
Definition: scriptnum10.h:22
CScriptNum10::operator!=
bool operator!=(const CScriptNum10 &rhs) const
Definition: scriptnum10.h:71
CScriptNum10::operator-=
CScriptNum10 & operator-=(const CScriptNum10 &rhs)
Definition: scriptnum10.h:83
CScriptNum10::getvch
std::vector< unsigned char > getvch() const
Definition: scriptnum10.h:122
CScriptNum10::set_vch
static int64_t set_vch(const std::vector< unsigned char > &vch)
Definition: scriptnum10.h:161