1 | // Copyright (C) 2022 The Qt Company Ltd. |
2 | // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only |
3 | |
4 | #ifndef QSTRINGCONVERTER_BASE_H |
5 | #define QSTRINGCONVERTER_BASE_H |
6 | |
7 | #if 0 |
8 | // QStringConverter(Base) class are handled in qstringconverter |
9 | #pragma qt_sync_stop_processing |
10 | #endif |
11 | |
12 | #include <optional> |
13 | |
14 | #include <QtCore/qglobal.h> // QT_{BEGIN,END}_NAMESPACE |
15 | #include <QtCore/qflags.h> // Q_DECLARE_FLAGS |
16 | |
17 | #include <cstring> |
18 | |
19 | QT_BEGIN_NAMESPACE |
20 | |
21 | class QByteArrayView; |
22 | class QChar; |
23 | class QByteArrayView; |
24 | class QStringView; |
25 | |
26 | class QStringConverterBase |
27 | { |
28 | public: |
29 | enum class Flag { |
30 | Default = 0, |
31 | Stateless = 0x1, |
32 | ConvertInvalidToNull = 0x2, |
33 | WriteBom = 0x4, |
34 | ConvertInitialBom = 0x8, |
35 | UsesIcu = 0x10, |
36 | }; |
37 | Q_DECLARE_FLAGS(Flags, Flag) |
38 | |
39 | struct State { |
40 | constexpr State(Flags f = Flag::Default) noexcept |
41 | : flags(f), state_data{0, 0, 0, 0} {} |
42 | ~State() { clear(); } |
43 | |
44 | State(State &&other) noexcept |
45 | : flags(other.flags), |
46 | remainingChars(other.remainingChars), |
47 | invalidChars(other.invalidChars), |
48 | state_data{other.state_data[0], other.state_data[1], |
49 | other.state_data[2], other.state_data[3]}, |
50 | clearFn(other.clearFn) |
51 | { other.clearFn = nullptr; } |
52 | State &operator=(State &&other) noexcept |
53 | { |
54 | clear(); |
55 | flags = other.flags; |
56 | remainingChars = other.remainingChars; |
57 | invalidChars = other.invalidChars; |
58 | std::memmove(dest: state_data, src: other.state_data, n: sizeof state_data); // self-assignment-safe |
59 | clearFn = other.clearFn; |
60 | other.clearFn = nullptr; |
61 | return *this; |
62 | } |
63 | Q_CORE_EXPORT void clear() noexcept; |
64 | Q_CORE_EXPORT void reset() noexcept; |
65 | |
66 | Flags flags; |
67 | int internalState = 0; |
68 | qsizetype remainingChars = 0; |
69 | qsizetype invalidChars = 0; |
70 | |
71 | union { |
72 | uint state_data[4]; |
73 | void *d[2]; |
74 | }; |
75 | using ClearDataFn = void (*)(State *) noexcept; |
76 | ClearDataFn clearFn = nullptr; |
77 | private: |
78 | Q_DISABLE_COPY(State) |
79 | }; |
80 | protected: |
81 | ~QStringConverterBase() = default; |
82 | }; |
83 | Q_DECLARE_OPERATORS_FOR_FLAGS(QStringConverterBase::Flags) |
84 | |
85 | class QStringConverter : public QStringConverterBase |
86 | { |
87 | public: |
88 | |
89 | enum Encoding { |
90 | Utf8, |
91 | Utf16, |
92 | Utf16LE, |
93 | Utf16BE, |
94 | Utf32, |
95 | Utf32LE, |
96 | Utf32BE, |
97 | Latin1, |
98 | System, |
99 | LastEncoding = System |
100 | }; |
101 | #ifdef Q_QDOC |
102 | // document the flags here |
103 | enum class Flag { |
104 | Default = 0, |
105 | Stateless = 0x1, |
106 | ConvertInvalidToNull = 0x2, |
107 | WriteBom = 0x4, |
108 | ConvertInitialBom = 0x8, |
109 | UsesIcu = 0x10, |
110 | }; |
111 | Q_DECLARE_FLAGS(Flags, Flag) |
112 | #endif |
113 | |
114 | protected: |
115 | |
116 | struct Interface |
117 | { |
118 | using DecoderFn = QChar * (*)(QChar *out, QByteArrayView in, State *state); |
119 | using LengthFn = qsizetype (*)(qsizetype inLength); |
120 | using EncoderFn = char * (*)(char *out, QStringView in, State *state); |
121 | const char *name = nullptr; |
122 | DecoderFn toUtf16 = nullptr; |
123 | LengthFn toUtf16Len = nullptr; |
124 | EncoderFn fromUtf16 = nullptr; |
125 | LengthFn fromUtf16Len = nullptr; |
126 | }; |
127 | |
128 | constexpr QStringConverter() noexcept |
129 | : iface(nullptr) |
130 | {} |
131 | constexpr explicit QStringConverter(Encoding encoding, Flags f) |
132 | : iface(&encodingInterfaces[qsizetype(encoding)]), state(f) |
133 | {} |
134 | constexpr explicit QStringConverter(const Interface *i) noexcept |
135 | : iface(i) |
136 | {} |
137 | Q_CORE_EXPORT explicit QStringConverter(const char *name, Flags f); |
138 | |
139 | |
140 | ~QStringConverter() = default; |
141 | |
142 | public: |
143 | QStringConverter(QStringConverter &&) = default; |
144 | QStringConverter &operator=(QStringConverter &&) = default; |
145 | |
146 | bool isValid() const noexcept { return iface != nullptr; } |
147 | |
148 | void resetState() noexcept |
149 | { |
150 | state.reset(); |
151 | } |
152 | bool hasError() const noexcept { return state.invalidChars != 0; } |
153 | |
154 | Q_CORE_EXPORT const char *name() const noexcept; |
155 | |
156 | Q_CORE_EXPORT static std::optional<Encoding> encodingForName(const char *name) noexcept; |
157 | Q_CORE_EXPORT static const char *nameForEncoding(Encoding e); |
158 | Q_CORE_EXPORT static std::optional<Encoding> |
159 | encodingForData(QByteArrayView data, char16_t expectedFirstCharacter = 0) noexcept; |
160 | Q_CORE_EXPORT static std::optional<Encoding> encodingForHtml(QByteArrayView data); |
161 | |
162 | protected: |
163 | const Interface *iface; |
164 | State state; |
165 | private: |
166 | Q_CORE_EXPORT static const Interface encodingInterfaces[Encoding::LastEncoding + 1]; |
167 | }; |
168 | |
169 | QT_END_NAMESPACE |
170 | |
171 | #endif |
172 | |