1  // Copyright (c) 2009-2010 Satoshi Nakamoto
 2  // Copyright (c) 2009-2022 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  std::string FormatMoney(const CAmount n)
17  {
18      // Note: not using straight sprintf here because we do NOT want
19      // localized number formatting.
20      static_assert(COIN > 1);
21      int64_t quotient = n / COIN;
22      int64_t remainder = n % COIN;
23      if (n < 0) {
24          quotient = -quotient;
25          remainder = -remainder;
26      }
27      std::string str = strprintf("%d.%08d", quotient, remainder);
28  
29      // Right-trim excess zeros before the decimal point:
30      int nTrim = 0;
31      for (int i = str.size()-1; (str[i] == '0' && IsDigit(str[i-2])); --i)
32          ++nTrim;
33      if (nTrim)
34          str.erase(str.size()-nTrim, nTrim);
35  
36      if (n < 0)
37          str.insert(uint32_t{0}, 1, '-');
38      return str;
39  }
40  
41  
42  std::optional<CAmount> ParseMoney(const std::string& money_string)
43  {
44      if (!ContainsNoNUL(money_string)) {
45          return std::nullopt;
46      }
47      const std::string str = TrimString(money_string);
48      if (str.empty()) {
49          return std::nullopt;
50      }
51  
52      std::string strWhole;
53      int64_t nUnits = 0;
54      const char* p = str.c_str();
55      for (; *p; p++)
56      {
57          if (*p == '.')
58          {
59              p++;
60              int64_t nMult = COIN / 10;
61              while (IsDigit(*p) && (nMult > 0))
62              {
63                  nUnits += nMult * (*p++ - '0');
64                  nMult /= 10;
65              }
66              break;
67          }
68          if (IsSpace(*p))
69              return std::nullopt;
70          if (!IsDigit(*p))
71              return std::nullopt;
72          strWhole.insert(strWhole.end(), *p);
73      }
74      if (*p) {
75          return std::nullopt;
76      }
77      if (strWhole.size() > 10) // guard against 63 bit overflow
78          return std::nullopt;
79      if (nUnits < 0 || nUnits > COIN)
80          return std::nullopt;
81      int64_t nWhole = LocaleIndependentAtoi<int64_t>(strWhole);
82      CAmount value = nWhole * COIN + nUnits;
83  
84      if (!MoneyRange(value)) {
85          return std::nullopt;
86      }
87  
88      return value;
89  }