summaryrefslogtreecommitdiff
path: root/src/mongo/shell/linenoise_utf8.h
blob: dca7a8b0ef43fa67aa6afe8e213f37cd028f173a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
/**
 *    Copyright (C) 2018-present MongoDB, Inc.
 *
 *    This program is free software: you can redistribute it and/or modify
 *    it under the terms of the Server Side Public License, version 1,
 *    as published by MongoDB, Inc.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    Server Side Public License for more details.
 *
 *    You should have received a copy of the Server Side Public License
 *    along with this program. If not, see
 *    <http://www.mongodb.com/licensing/server-side-public-license>.
 *
 *    As a special exception, the copyright holders give permission to link the
 *    code of portions of this program with the OpenSSL library under certain
 *    conditions as described in each individual source file and distribute
 *    linked combinations including the program with the OpenSSL library. You
 *    must comply with the Server Side Public License in all respects for
 *    all of the code used other than as permitted herein. If you modify file(s)
 *    with this exception, you may extend this exception to your version of the
 *    file(s), but you are not obligated to do so. If you do not wish to do so,
 *    delete this exception statement from your version. If you delete this
 *    exception statement from all source files in the program, then also delete
 *    it in the license file.
 */

#include <algorithm>
#include <memory>
#include <string.h>

namespace linenoise_utf8 {

typedef unsigned char UChar8;  // UTF-8 octet
typedef char32_t UChar32;      // Unicode code point

// Error bits (or-ed together) returned from utf8toUChar32string
//
enum BadUTF8 { BadUTF8_no_error = 0x00, BadUTF8_invalid_byte = 0x01, BadUTF8_surrogate = 0x02 };

/**
 * Convert a null terminated UTF-8 std::string from UTF-8 and store it in a UChar32 destination
 * buffer Always null terminates the destination std::string if at least one character position is
 * available Errors in the UTF-8 encoding will be handled in two ways: the erroneous characters will
 * be converted to the Unicode error character U+FFFD and flag bits will be set in the
 * conversionErrorCode int.
 *
 * @param uchar32output                 Destination UChar32 buffer
 * @param utf8input                     Source UTF-8 string
 * @param outputBufferSizeInCharacters  Destination buffer size in characters
 * @param outputUnicodeCharacterCount   Number of UChar32 characters placed in output buffer
 * @param conversionErrorCode           Flag bits from enum BadUTF8, or zero if no error
 */
void copyString8to32(UChar32* uchar32output,
                     const UChar8* utf8input,
                     size_t outputBufferSizeInCharacters,
                     size_t& outputUnicodeCharacterCount,
                     int& conversionErrorCode);

/**
 * Copy a null terminated UChar32 std::string to a UChar32 destination buffer
 * Always null terminates the destination std::string if at least one character position is
 * available
 *
 * @param dest32                    Destination UChar32 buffer
 * @param source32                  Source UChar32 string
 * @param destLengthInCharacters    Destination buffer length in characters
 */
void copyString32(UChar32* dest32, const UChar32* source32, size_t destLengthInCharacters);

/**
 * Convert a specified number of UChar32 characters from a possibly null terminated UChar32
 * std::string to UTF-8 and store it in a UChar8 destination buffer
 * Always null terminates the destination std::string if at least one character position is
 * available
 *
 * @param dest8                     Destination UChar8 buffer
 * @param source32                  Source UChar32 string
 * @param outputBufferSizeInBytes   Destination buffer size in bytes
 * @param charCount                 Maximum number of UChar32 characters to process
 * @return                          Count of bytes written to output buffer, not including null
 *                                  terminator
 */
size_t copyString32to8counted(UChar8* dest8,
                              const UChar32* source32,
                              size_t outputBufferSizeInBytes,
                              size_t charCount);

/**
 * Convert a null terminated UChar32 std::string to UTF-8 and store it in a UChar8 destination
 * buffer
 * Always null terminates the destination std::string if at least one character position is
 * available
 *
 * @param dest8                     Destination UChar8 buffer
 * @param source32                  Source UChar32 string
 * @param outputBufferSizeInBytes   Destination buffer size in bytes
 * @return                          Count of bytes written to output buffer, not including null
 *                                  terminator
 */
size_t copyString32to8(UChar8* dest8, const UChar32* source32, size_t outputBufferSizeInBytes);

/**
 * Count characters (i.e. Unicode code points, array elements) in a null terminated UChar32 string
 *
 * @param str32     Source UChar32 string
 * @return          std::string length in characters
 */
size_t strlen32(const UChar32* str32);

/**
 * Compare two UChar32 null-terminated strings with length parameter
 *
 * @param first32   First std::string to compare
 * @param second32  Second std::string to compare
 * @param length    Maximum number of characters to compare
 * @return          Negative if first < second, positive if first > second, zero if equal
 */
int strncmp32(UChar32* first32, UChar32* second32, size_t length);

/**
 * Internally convert an array of UChar32 characters of specified length to UTF-8 and write it to
 * fileHandle
 *
 * @param fileHandle                File handle to write to
 * @param string32                  Source UChar32 character array, may not be null terminated
 * @param sourceLengthInCharacters  Number of source characters to convert and write
 * @return                          Number of bytes written, -1 on error
 */
int write32(int fileHandle, const UChar32* string32, unsigned int sourceLengthInCharacters);

/**
 * Template and classes for UChar8 and UChar32 strings
 */
template <typename char_type>
struct UtfStringMixin {
    typedef char_type char_t;  // inherited

    UtfStringMixin() : _len(0), _cap(0), _chars(0) {}

    UtfStringMixin(const UtfStringMixin& other)  // copies like std::string
        : _len(other._len), _cap(other._len + 1), _chars(other._chars), _str(new char_t[_cap]) {
        memcpy(_str.get(), other._str.get(), _cap * sizeof(char_t));
    }

    UtfStringMixin& operator=(UtfStringMixin copy) {
        this->swap(copy);
        return *this;
    }

    char_t* get() const {
        return _str.get();
    }
    char_t& operator[](size_t idx) {
        return _str[idx];
    }
    const char_t& operator[](size_t idx) const {
        return _str[idx];
    }

    size_t length() const {
        return _len;
    }
    size_t capacity() const {
        return _cap;
    }
    size_t chars() const {
        return _chars;
    }

    void swap(UtfStringMixin& other) {
        std::swap(_len, other._len);
        std::swap(_cap, other._cap);
        std::swap(_chars, other._chars);
        _str.swap(other._str);
    }

protected:
    size_t _len;    // in units of char_t without nul
    size_t _cap;    // size of _str buffer including nul
    size_t _chars;  // number of codepoints
    std::unique_ptr<char_t[]> _str;
};

struct Utf32String;

struct Utf8String : public UtfStringMixin<UChar8> {
    Utf8String() {}
    explicit Utf8String(const UChar32* s, int chars = -1) {
        if (chars == -1) {
            initFrom32(s, strlen32(s));
        } else {
            initFrom32(s, chars);
        }
    }
    explicit Utf8String(const Utf32String& c);  // defined after utf32String

private:
    void initFrom32(const UChar32* s, int chars) {
        _chars = chars;
        _cap = _chars * sizeof(UChar32) + 1;
        _str.reset(new char_t[_cap]);
        _len = copyString32to8counted(_str.get(), s, _cap, chars);
    }
};

struct Utf32String : public UtfStringMixin<UChar32> {
    Utf32String() {}
    explicit Utf32String(const UChar32* s) {
        _chars = _len = strlen32(s);
        _cap = _len + 1;
        _str.reset(new UChar32[_cap]);
        memcpy(_str.get(), s, _cap * sizeof(UChar32));
    }
    explicit Utf32String(const UChar32* s, int textLen) {
        _chars = _len = textLen;
        _cap = _len + 1;
        _str.reset(new UChar32[_cap]);
        memcpy(_str.get(), s, _len * sizeof(UChar32));
        _str[_len] = 0;
    }
    explicit Utf32String(const UChar8* s, int chars = -1) {
        initFrom8(s, chars);
    }
    explicit Utf32String(const Utf8String& c) {
        initFrom8(c.get(), c.chars());
    }
    explicit Utf32String(size_t reserve) {
        _len = 0;
        _cap = reserve;
        _chars = 0;
        _str.reset(new UChar32[_cap]);
        _str[0] = 0;
    }
    void initFromBuffer(void) {
        _chars = _len = strlen32(_str.get());
    }

private:
    void initFrom8(const UChar8* s, int chars) {
        Utf32String temp;
        if (chars == -1) {
            temp._cap = strlen(reinterpret_cast<const char*>(s)) + 1;  // worst case ASCII
        } else {
            temp._cap = chars + 1;
        }
        temp._str.reset(new char_t[temp._cap]);
        int error;
        copyString8to32(temp._str.get(), s, temp._cap, temp._chars, error);
        temp._len = temp._chars;
        this->swap(temp);
    }
};

inline Utf8String::Utf8String(const Utf32String& s) {
    initFrom32(s.get(), s.chars());
}

}  // namespace linenoise_utf8