1 // Copyright 2012 The Chromium Authors 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifdef UNSAFE_BUFFERS_BUILD 6 // TODO(crbug.com/40284755): Remove this and spanify to fix the errors. 7 #pragma allow_unsafe_buffers 8 #endif 9 10 #ifndef BASE_STRINGS_STRING_NUMBER_CONVERSIONS_H_ 11 #define BASE_STRINGS_STRING_NUMBER_CONVERSIONS_H_ 12 13 #include <stddef.h> 14 #include <stdint.h> 15 16 #include <string> 17 #include <string_view> 18 #include <vector> 19 20 #include "base/base_export.h" 21 #include "base/containers/span.h" 22 #include "build/build_config.h" 23 24 // ---------------------------------------------------------------------------- 25 // IMPORTANT MESSAGE FROM YOUR SPONSOR 26 // 27 // Please do not add "convenience" functions for converting strings to integers 28 // that return the value and ignore success/failure. That encourages people to 29 // write code that doesn't properly handle the error conditions. 30 // 31 // DO NOT use these functions in any UI unless it's NOT localized on purpose. 32 // Instead, use base::MessageFormatter for a complex message with numbers 33 // (integer, float, double) embedded or base::Format{Number,Double,Percent} to 34 // just format a single number/percent. Note that some languages use native 35 // digits instead of ASCII digits while others use a group separator or decimal 36 // point different from ',' and '.'. Using these functions in the UI would lead 37 // numbers to be formatted in a non-native way. 38 // ---------------------------------------------------------------------------- 39 40 namespace base { 41 42 // Number -> string conversions ------------------------------------------------ 43 44 // Ignores locale! see warning above. 45 BASE_EXPORT std::string NumberToString(int value); 46 BASE_EXPORT std::u16string NumberToString16(int value); 47 BASE_EXPORT std::string NumberToString(unsigned int value); 48 BASE_EXPORT std::u16string NumberToString16(unsigned int value); 49 BASE_EXPORT std::string NumberToString(long value); 50 BASE_EXPORT std::u16string NumberToString16(long value); 51 BASE_EXPORT std::string NumberToString(unsigned long value); 52 BASE_EXPORT std::u16string NumberToString16(unsigned long value); 53 BASE_EXPORT std::string NumberToString(long long value); 54 BASE_EXPORT std::u16string NumberToString16(long long value); 55 BASE_EXPORT std::string NumberToString(unsigned long long value); 56 BASE_EXPORT std::u16string NumberToString16(unsigned long long value); 57 BASE_EXPORT std::string NumberToString(double value); 58 BASE_EXPORT std::u16string NumberToString16(double value); 59 60 // String -> number conversions ------------------------------------------------ 61 62 // Perform a best-effort conversion of the input string to a numeric type, 63 // setting |*output| to the result of the conversion. Returns true for 64 // "perfect" conversions; returns false in the following cases: 65 // - Overflow. |*output| will be set to the maximum value supported 66 // by the data type. 67 // - Underflow. |*output| will be set to the minimum value supported 68 // by the data type. 69 // - Trailing characters in the string after parsing the number. |*output| 70 // will be set to the value of the number that was parsed. 71 // - Leading whitespace in the string before parsing the number. |*output| will 72 // be set to the value of the number that was parsed. 73 // - No characters parseable as a number at the beginning of the string. 74 // |*output| will be set to 0. 75 // - Empty string. |*output| will be set to 0. 76 // WARNING: Will write to |output| even when returning false. 77 // Read the comments above carefully. 78 BASE_EXPORT bool StringToInt(std::string_view input, int* output); 79 BASE_EXPORT bool StringToInt(std::u16string_view input, int* output); 80 81 BASE_EXPORT bool StringToUint(std::string_view input, unsigned* output); 82 BASE_EXPORT bool StringToUint(std::u16string_view input, unsigned* output); 83 84 BASE_EXPORT bool StringToInt64(std::string_view input, int64_t* output); 85 BASE_EXPORT bool StringToInt64(std::u16string_view input, int64_t* output); 86 87 BASE_EXPORT bool StringToUint64(std::string_view input, uint64_t* output); 88 BASE_EXPORT bool StringToUint64(std::u16string_view input, uint64_t* output); 89 90 BASE_EXPORT bool StringToSizeT(std::string_view input, size_t* output); 91 BASE_EXPORT bool StringToSizeT(std::u16string_view input, size_t* output); 92 93 // For floating-point conversions, only conversions of input strings in decimal 94 // form are defined to work. Behavior with strings representing floating-point 95 // numbers in hexadecimal, and strings representing non-finite values (such as 96 // NaN and inf) is undefined. Otherwise, these behave the same as the integral 97 // variants. This expects the input string to NOT be specific to the locale. 98 // If your input is locale specific, use ICU to read the number. 99 // WARNING: Will write to |output| even when returning false. 100 // Read the comments here and above StringToInt() carefully. 101 BASE_EXPORT bool StringToDouble(std::string_view input, double* output); 102 BASE_EXPORT bool StringToDouble(std::u16string_view input, double* output); 103 104 // Hex encoding ---------------------------------------------------------------- 105 106 // Returns a hex string representation of a binary buffer. The returned hex 107 // string will be in upper case. This function does not check if |size| is 108 // within reasonable limits since it's written with trusted data in mind. If 109 // you suspect that the data you want to format might be large, the absolute 110 // max size for |size| should be is 111 // std::numeric_limits<size_t>::max() / 2 112 BASE_EXPORT std::string HexEncode(base::span<const uint8_t> bytes); 113 BASE_EXPORT std::string HexEncode(std::string_view chars); 114 // TODO(crbug.com/40284755): The pointer-based overload should be removed. 115 BASE_EXPORT std::string HexEncode(const void* bytes, size_t size); 116 117 // Appends a hex representation of `byte`, as two uppercase (by default) 118 // characters, to `output`. This is a useful primitive in larger conversion 119 // routines. 120 inline void AppendHexEncodedByte(uint8_t byte, 121 std::string& output, 122 bool uppercase = true) { 123 static constexpr char kHexCharsUpper[] = {'0', '1', '2', '3', '4', '5', 124 '6', '7', '8', '9', 'A', 'B', 125 'C', 'D', 'E', 'F'}; 126 static constexpr char kHexCharsLower[] = {'0', '1', '2', '3', '4', '5', 127 '6', '7', '8', '9', 'a', 'b', 128 'c', 'd', 'e', 'f'}; 129 const char* const hex_chars = uppercase ? kHexCharsUpper : kHexCharsLower; 130 output.append({hex_chars[byte >> 4], hex_chars[byte & 0xf]}); 131 } 132 133 // Best effort conversion, see StringToInt above for restrictions. 134 // Will only successful parse hex values that will fit into |output|, i.e. 135 // -0x80000000 < |input| < 0x7FFFFFFF. 136 BASE_EXPORT bool HexStringToInt(std::string_view input, int* output); 137 138 // Best effort conversion, see StringToInt above for restrictions. 139 // Will only successful parse hex values that will fit into |output|, i.e. 140 // 0x00000000 < |input| < 0xFFFFFFFF. 141 // The string is not required to start with 0x. 142 BASE_EXPORT bool HexStringToUInt(std::string_view input, uint32_t* output); 143 144 // Best effort conversion, see StringToInt above for restrictions. 145 // Will only successful parse hex values that will fit into |output|, i.e. 146 // -0x8000000000000000 < |input| < 0x7FFFFFFFFFFFFFFF. 147 BASE_EXPORT bool HexStringToInt64(std::string_view input, int64_t* output); 148 149 // Best effort conversion, see StringToInt above for restrictions. 150 // Will only successful parse hex values that will fit into |output|, i.e. 151 // 0x0000000000000000 < |input| < 0xFFFFFFFFFFFFFFFF. 152 // The string is not required to start with 0x. 153 BASE_EXPORT bool HexStringToUInt64(std::string_view input, uint64_t* output); 154 155 // Similar to the previous functions, except that output is a vector of bytes. 156 // |*output| will contain as many bytes as were successfully parsed prior to the 157 // error. There is no overflow, but input.size() must be evenly divisible by 2. 158 // Leading 0x or +/- are not allowed. 159 BASE_EXPORT bool HexStringToBytes(std::string_view input, 160 std::vector<uint8_t>* output); 161 162 // Same as HexStringToBytes, but for an std::string. 163 BASE_EXPORT bool HexStringToString(std::string_view input, std::string* output); 164 165 // Decodes the hex string |input| into a presized |output|. The output buffer 166 // must be sized exactly to |input.size() / 2| or decoding will fail and no 167 // bytes will be written to |output|. Decoding an empty input is also 168 // considered a failure. When decoding fails due to encountering invalid input 169 // characters, |output| will have been filled with the decoded bytes up until 170 // the failure. 171 BASE_EXPORT bool HexStringToSpan(std::string_view input, 172 base::span<uint8_t> output); 173 174 } // namespace base 175 176 #if BUILDFLAG(IS_WIN) 177 #include "base/strings/string_number_conversions_win.h" 178 #endif 179 180 #endif // BASE_STRINGS_STRING_NUMBER_CONVERSIONS_H_ 181