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 | #include <QtCore/qcontainerfwd.h> |
17 | |
18 | #include <cstring> |
19 | |
20 | QT_BEGIN_NAMESPACE |
21 | |
22 | class QByteArrayView; |
23 | class QChar; |
24 | class QByteArrayView; |
25 | class QStringView; |
26 | |
27 | class QStringConverterBase |
28 | { |
29 | public: |
30 | enum class Flag { |
31 | Default = 0, |
32 | Stateless = 0x1, |
33 | ConvertInvalidToNull = 0x2, |
34 | WriteBom = 0x4, |
35 | ConvertInitialBom = 0x8, |
36 | UsesIcu = 0x10, |
37 | }; |
38 | Q_DECLARE_FLAGS(Flags, Flag) |
39 | |
40 | struct State { |
41 | constexpr State(Flags f = Flag::Default) noexcept |
42 | : flags(f), state_data{0, 0, 0, 0} {} |
43 | ~State() { clear(); } |
44 | |
45 | State(State &&other) noexcept |
46 | : flags(other.flags), |
47 | remainingChars(other.remainingChars), |
48 | invalidChars(other.invalidChars), |
49 | state_data{other.state_data[0], other.state_data[1], |
50 | other.state_data[2], other.state_data[3]}, |
51 | clearFn(other.clearFn) |
52 | { other.clearFn = nullptr; } |
53 | State &operator=(State &&other) noexcept |
54 | { |
55 | clear(); |
56 | flags = other.flags; |
57 | remainingChars = other.remainingChars; |
58 | invalidChars = other.invalidChars; |
59 | std::memmove(dest: state_data, src: other.state_data, n: sizeof state_data); // self-assignment-safe |
60 | clearFn = other.clearFn; |
61 | other.clearFn = nullptr; |
62 | return *this; |
63 | } |
64 | Q_CORE_EXPORT void clear() noexcept; |
65 | Q_CORE_EXPORT void reset() noexcept; |
66 | |
67 | Flags flags; |
68 | int internalState = 0; |
69 | qsizetype remainingChars = 0; |
70 | qsizetype invalidChars = 0; |
71 | |
72 | union { |
73 | uint state_data[4]; |
74 | void *d[2]; |
75 | }; |
76 | using ClearDataFn = void (*)(State *) noexcept; |
77 | ClearDataFn clearFn = nullptr; |
78 | private: |
79 | Q_DISABLE_COPY(State) |
80 | }; |
81 | protected: |
82 | ~QStringConverterBase() = default; |
83 | }; |
84 | Q_DECLARE_OPERATORS_FOR_FLAGS(QStringConverterBase::Flags) |
85 | |
86 | class QStringConverter : public QStringConverterBase |
87 | { |
88 | public: |
89 | |
90 | enum Encoding { |
91 | Utf8, |
92 | Utf16, |
93 | Utf16LE, |
94 | Utf16BE, |
95 | Utf32, |
96 | Utf32LE, |
97 | Utf32BE, |
98 | Latin1, |
99 | System, |
100 | LastEncoding = System |
101 | }; |
102 | #ifdef Q_QDOC |
103 | // document the flags here |
104 | enum class Flag { |
105 | Default = 0, |
106 | Stateless = 0x1, |
107 | ConvertInvalidToNull = 0x2, |
108 | WriteBom = 0x4, |
109 | ConvertInitialBom = 0x8, |
110 | UsesIcu = 0x10, |
111 | }; |
112 | Q_DECLARE_FLAGS(Flags, Flag) |
113 | #endif |
114 | |
115 | protected: |
116 | |
117 | struct Interface |
118 | { |
119 | using DecoderFn = QChar * (*)(QChar *out, QByteArrayView in, State *state); |
120 | using LengthFn = qsizetype (*)(qsizetype inLength); |
121 | using EncoderFn = char * (*)(char *out, QStringView in, State *state); |
122 | const char *name = nullptr; |
123 | DecoderFn toUtf16 = nullptr; |
124 | LengthFn toUtf16Len = nullptr; |
125 | EncoderFn fromUtf16 = nullptr; |
126 | LengthFn fromUtf16Len = nullptr; |
127 | }; |
128 | |
129 | constexpr QStringConverter() noexcept |
130 | : iface(nullptr) |
131 | {} |
132 | constexpr explicit QStringConverter(Encoding encoding, Flags f) |
133 | : iface(&encodingInterfaces[qsizetype(encoding)]), state(f) |
134 | {} |
135 | constexpr explicit QStringConverter(const Interface *i) noexcept |
136 | : iface(i) |
137 | {} |
138 | Q_CORE_EXPORT explicit QStringConverter(const char *name, Flags f); |
139 | |
140 | |
141 | ~QStringConverter() = default; |
142 | |
143 | public: |
144 | QStringConverter(QStringConverter &&) = default; |
145 | QStringConverter &operator=(QStringConverter &&) = default; |
146 | |
147 | bool isValid() const noexcept { return iface != nullptr; } |
148 | |
149 | void resetState() noexcept |
150 | { |
151 | state.reset(); |
152 | } |
153 | bool hasError() const noexcept { return state.invalidChars != 0; } |
154 | |
155 | Q_CORE_EXPORT const char *name() const noexcept; |
156 | |
157 | Q_CORE_EXPORT static std::optional<Encoding> encodingForName(const char *name) noexcept; |
158 | Q_CORE_EXPORT static const char *nameForEncoding(Encoding e); |
159 | Q_CORE_EXPORT static std::optional<Encoding> |
160 | encodingForData(QByteArrayView data, char16_t expectedFirstCharacter = 0) noexcept; |
161 | Q_CORE_EXPORT static std::optional<Encoding> encodingForHtml(QByteArrayView data); |
162 | |
163 | Q_CORE_EXPORT static QStringList availableCodecs(); |
164 | |
165 | protected: |
166 | const Interface *iface; |
167 | State state; |
168 | private: |
169 | Q_CORE_EXPORT static const Interface encodingInterfaces[Encoding::LastEncoding + 1]; |
170 | }; |
171 | |
172 | QT_END_NAMESPACE |
173 | |
174 | #endif |
175 | |