1  // Copyright (c) 2009-2010 Satoshi Nakamoto
 2  // Copyright (c) 2009-present 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 <cstdint>
14  #include <optional>
15  
16  using util::ContainsNoNUL;
17  using util::TrimString;
18  
19  std::string FormatMoney(const CAmount n)
20  {
21      // Note: not using straight sprintf here because we do NOT want
22      // localized number formatting.
23      static_assert(COIN > 1);
24      int64_t quotient = n / COIN;
25      int64_t remainder = n % COIN;
26      if (n < 0) {
27          quotient = -quotient;
28          remainder = -remainder;
29      }
30      std::string str = strprintf("%d.%08d", quotient, remainder);
31  
32      // Right-trim excess zeros before the decimal point:
33      int nTrim = 0;
34      for (int i = str.size()-1; (str[i] == '0' && IsDigit(str[i-2])); --i)
35          ++nTrim;
36      if (nTrim)
37          str.erase(str.size()-nTrim, nTrim);
38  
39      if (n < 0)
40          str.insert(uint32_t{0}, 1, '-');
41      return str;
42  }
43  
44  
45  std::optional<CAmount> ParseMoney(const std::string& money_string)
46  {
47      if (!ContainsNoNUL(money_string)) {
48          return std::nullopt;
49      }
50      const std::string str = TrimString(money_string);
51      if (str.empty()) {
52          return std::nullopt;
53      }
54  
55      std::string strWhole;
56      int64_t nUnits = 0;
57      const char* p = str.c_str();
58      for (; *p; p++)
59      {
60          if (*p == '.')
61          {
62              p++;
63              int64_t nMult = COIN / 10;
64              while (IsDigit(*p) && (nMult > 0))
65              {
66                  nUnits += nMult * (*p++ - '0');
67                  nMult /= 10;
68              }
69              break;
70          }
71          if (IsSpace(*p))
72              return std::nullopt;
73          if (!IsDigit(*p))
74              return std::nullopt;
75          strWhole.insert(strWhole.end(), *p);
76      }
77      if (*p) {
78          return std::nullopt;
79      }
80      if (strWhole.size() > 10) // guard against 63 bit overflow
81          return std::nullopt;
82      if (nUnits < 0 || nUnits > COIN)
83          return std::nullopt;
84      int64_t nWhole = LocaleIndependentAtoi<int64_t>(strWhole);
85      CAmount value = nWhole * COIN + nUnits;
86  
87      if (!MoneyRange(value)) {
88          return std::nullopt;
89      }
90  
91      return value;
92  }