Bitcoin Core  22.99.0
P2P Digital Currency
moneystr.cpp
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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 #include <util/moneystr.h>
7 
8 #include <consensus/amount.h>
9 #include <tinyformat.h>
10 #include <util/strencodings.h>
11 #include <util/string.h>
12 
13 #include <optional>
14 
15 std::string FormatMoney(const CAmount n)
16 {
17  // Note: not using straight sprintf here because we do NOT want
18  // localized number formatting.
19  static_assert(COIN > 1);
20  int64_t quotient = n / COIN;
21  int64_t remainder = n % COIN;
22  if (n < 0) {
23  quotient = -quotient;
24  remainder = -remainder;
25  }
26  std::string str = strprintf("%d.%08d", quotient, remainder);
27 
28  // Right-trim excess zeros before the decimal point:
29  int nTrim = 0;
30  for (int i = str.size()-1; (str[i] == '0' && IsDigit(str[i-2])); --i)
31  ++nTrim;
32  if (nTrim)
33  str.erase(str.size()-nTrim, nTrim);
34 
35  if (n < 0)
36  str.insert((unsigned int)0, 1, '-');
37  return str;
38 }
39 
40 
41 std::optional<CAmount> ParseMoney(const std::string& money_string)
42 {
43  if (!ValidAsCString(money_string)) {
44  return std::nullopt;
45  }
46  const std::string str = TrimString(money_string);
47  if (str.empty()) {
48  return std::nullopt;
49  }
50 
51  std::string strWhole;
52  int64_t nUnits = 0;
53  const char* p = str.c_str();
54  for (; *p; p++)
55  {
56  if (*p == '.')
57  {
58  p++;
59  int64_t nMult = COIN / 10;
60  while (IsDigit(*p) && (nMult > 0))
61  {
62  nUnits += nMult * (*p++ - '0');
63  nMult /= 10;
64  }
65  break;
66  }
67  if (IsSpace(*p))
68  return std::nullopt;
69  if (!IsDigit(*p))
70  return std::nullopt;
71  strWhole.insert(strWhole.end(), *p);
72  }
73  if (*p) {
74  return std::nullopt;
75  }
76  if (strWhole.size() > 10) // guard against 63 bit overflow
77  return std::nullopt;
78  if (nUnits < 0 || nUnits > COIN)
79  return std::nullopt;
80  int64_t nWhole = LocaleIndependentAtoi<int64_t>(strWhole);
81  CAmount value = nWhole * COIN + nUnits;
82 
83  if (!MoneyRange(value)) {
84  return std::nullopt;
85  }
86 
87  return value;
88 }
moneystr.h
string.h
MoneyRange
bool MoneyRange(const CAmount &nValue)
Definition: amount.h:26
TrimString
std::string TrimString(const std::string &str, const std::string &pattern=" \f\n\r\t\v")
Definition: string.h:18
ValidAsCString
bool ValidAsCString(const std::string &str) noexcept
Check if a string does not contain any embedded NUL (\0) characters.
Definition: string.h:78
IsSpace
constexpr bool IsSpace(char c) noexcept
Tests if the given character is a whitespace character.
Definition: strencodings.h:121
tinyformat.h
strencodings.h
CAmount
int64_t CAmount
Amount in satoshis (Can be negative)
Definition: amount.h:12
IsDigit
constexpr bool IsDigit(char c)
Tests if the given character is a decimal digit.
Definition: strencodings.h:105
strprintf
#define strprintf
Format arguments and return the string or write to given std::ostream (see tinyformat::format doc for...
Definition: tinyformat.h:1164
ParseMoney
std::optional< CAmount > ParseMoney(const std::string &money_string)
Parse an amount denoted in full coins.
Definition: moneystr.cpp:41
COIN
static constexpr CAmount COIN
Definition: amount.h:14
amount.h
FormatMoney
std::string FormatMoney(const CAmount n)
Money parsing/formatting utilities.
Definition: moneystr.cpp:15