1/*
2 * Copyright (C) 2011 Research In Motion Limited. All rights reserved.
3 * Copyright (C) 2016-2019 Apple Inc. All rights reserved.
4 *
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Library General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
9 *
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Library General Public License for more details.
14 *
15 * You should have received a copy of the GNU Library General Public License
16 * along with this library; see the file COPYING.LIB. If not, write to
17 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
18 * Boston, MA 02110-1301, USA.
19 */
20
21#pragma once
22
23#include <array>
24#include <wtf/text/StringConcatenate.h>
25
26namespace WTF {
27
28enum HexConversionMode { Lowercase, Uppercase };
29
30namespace Internal {
31
32inline const LChar* hexDigitsForMode(HexConversionMode mode)
33{
34 static const LChar lowercaseHexDigits[17] = "0123456789abcdef";
35 static const LChar uppercaseHexDigits[17] = "0123456789ABCDEF";
36 return mode == Lowercase ? lowercaseHexDigits : uppercaseHexDigits;
37}
38
39WTF_EXPORT std::pair<LChar*, unsigned> appendHex(LChar* buffer, unsigned bufferSize, std::uintmax_t number, unsigned minimumDigits, HexConversionMode);
40
41template<size_t arraySize, typename NumberType>
42inline std::pair<LChar*, unsigned> appendHex(std::array<LChar, arraySize>& buffer, NumberType number, unsigned minimumDigits, HexConversionMode mode)
43{
44 return appendHex(&buffer.front(), buffer.size(), static_cast<typename std::make_unsigned<NumberType>::type>(number), minimumDigits, mode);
45}
46
47} // namespace Internal
48
49template<typename T>
50inline void appendByteAsHex(unsigned char byte, T& destination, HexConversionMode mode = Uppercase)
51{
52 auto* hexDigits = Internal::hexDigitsForMode(mode);
53 destination.append(hexDigits[byte >> 4]);
54 destination.append(hexDigits[byte & 0xF]);
55}
56
57// FIXME: Consider renaming to appendHex.
58template<typename NumberType, typename DestinationType>
59inline void appendUnsignedAsHex(NumberType number, DestinationType& destination, HexConversionMode mode = Uppercase)
60{
61 appendUnsignedAsHexFixedSize(number, destination, 0, mode);
62}
63
64// FIXME: Consider renaming to appendHex.
65// Same as appendUnsignedAsHex, but zero-padding to get at least the desired number of digits.
66template<typename NumberType, typename DestinationType>
67inline void appendUnsignedAsHexFixedSize(NumberType number, DestinationType& destination, unsigned minimumDigits, HexConversionMode mode = Uppercase)
68{
69 // Each byte can generate up to two digits.
70 std::array<LChar, sizeof(NumberType) * 2> buffer;
71 auto result = Internal::appendHex(buffer, number, minimumDigits, mode);
72 destination.append(result.first, result.second);
73}
74
75struct HexNumberBuffer {
76 std::array<LChar, 16> characters;
77 unsigned length;
78};
79
80template<typename NumberType> HexNumberBuffer hex(NumberType number, unsigned minimumDigits = 0, HexConversionMode mode = Uppercase)
81{
82 // Each byte can generate up to two digits.
83 HexNumberBuffer buffer;
84 static_assert(sizeof(buffer.characters) >= sizeof(NumberType) * 2, "number too large for hexNumber");
85 auto result = Internal::appendHex(buffer.characters, number, minimumDigits, mode);
86 buffer.length = result.second;
87 return buffer;
88}
89
90template<typename NumberType> HexNumberBuffer hex(NumberType number, HexConversionMode mode)
91{
92 return hex(number, 0, mode);
93}
94
95template<> class StringTypeAdapter<HexNumberBuffer> {
96public:
97 StringTypeAdapter(const HexNumberBuffer& buffer)
98 : m_buffer { buffer }
99 {
100 }
101
102 unsigned length() const { return m_buffer.length; }
103 bool is8Bit() const { return true; }
104 template<typename CharacterType> void writeTo(CharacterType* destination) const { StringImpl::copyCharacters(destination, characters(), length()); }
105
106private:
107 const LChar* characters() const { return &*(m_buffer.characters.end() - length()); }
108
109 const HexNumberBuffer& m_buffer;
110};
111
112} // namespace WTF
113
114using WTF::appendByteAsHex;
115using WTF::appendUnsignedAsHex;
116using WTF::appendUnsignedAsHexFixedSize;
117using WTF::hex;
118using WTF::Lowercase;
119