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
|
/**
* mds — A micro-display server
* Copyright © 2014 Mattias Andrée (maandree@member.fsf.org)
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* 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
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "string.h"
#include <libmdsserver/macros.h>
#include <stdlib.h>
#include <string.h>
/**
* Get the length of a string
*
* @param string The string
* @return The length of the string
*/
size_t string_length(const char32_t* restrict string)
{
size_t i = 0;
while (string[i] != -1)
i++;
return i;
}
/**
* Convert a NUL-terminated UTF-8 string to a -1-terminated UTF-32 string
*
* @param string The UTF-8 string
* @return The string in UTF-32, `NULL` on error
*/
char32_t* string_decode(const char* restrict string)
{
size_t i, j, n, length = 0;
char32_t* rc;
/* Get the length of the UTF-32 string, excluding termination. */
for (i = 0; string[i]; i++)
if ((string[i] & 0xC0) != 0x80)
length++;
/* Allocated UTF-32 string. */
fail_if (xmalloc(rc, length + 1, char32_t));
/* Convert to UTF-32. */
for (i = j = n = 0; string[i]; i++)
{
char c = string[i];
if (n)
{
rc[j] <<= 6, rc[j] |= c & 0x3F;
if (--n == 0)
j++;
}
else if ((c & 0xC0) == 0xC0)
{
while (c & 0x80)
n++, c = (char)(c << 1);
rc[j] = c >> n--;
}
else
rc[j++] = c & 255;
}
/* -1-terminate and return. */
return rc[length] = -1, rc;
fail:
return NULL;
}
/**
* Convert a -1-terminated UTF-32 string to a NUL-terminated Modified UTF-8 string
*
* Negative values apart from -1 are converted to 0x00
*
* @param string The UTF-32 string
* @return The string in UTF-8, `NULL` on error
*/
char* string_encode(const char32_t* restrict string)
{
size_t i, j, n = string_length(string);
char* restrict rc;
/* Allocated Modified UTF-8 string. */
fail_if (xmalloc(rc, 7 * n + 1, char));
/* Convert to Modified UTF-8. */
for (i = j = 0; i < n; i++)
{
#define _c(s) rc[j++] = (char)(((c >> (s)) & 0x3F) | 0x80)
#define _t(s) (0 < c) && ((uint32_t)c < (uint32_t)(1ULL << s))
char32_t c = string[i];
if (c == 0) rc[j++] = (char)0xC0, rc[j++] = (char)0x80;
else if (_t( 7)) rc[j++] = (char)c;
else if (_t(11)) rc[j++] = (char)((c >> 6) | 0xC0), _c( 0);
else if (_t(16)) rc[j++] = (char)((c >> 12) | 0xE0), _c( 6), _c( 0);
else if (_t(21)) rc[j++] = (char)((c >> 18) | 0xF0), _c(12), _c( 6), _c( 0);
/* UTF-8 actually ends here, fits 32 planes. */
else if (_t(26)) rc[j++] = (char)((c >> 24) | 0xF8), _c(18), _c(12), _c( 6), _c(0);
else if (_t(31)) rc[j++] = (char)((c >> 30) | 0xFC), _c(24), _c(18), _c(12), _c(6), _c(0);
/* The orginal UTF-8 specification ended here, fits 31 bits.
* However, we added another byte so we can fit 32 bits
* (actually we ca now fit 36 bits.)
* However, we only needed this in `string_decode` which would
* not require any changed, but we added it here for symmetry. */
else rc[j++] = (char)0xFE, _c(30), _c(24), _c(18), _c(12), _c(6), _c(0);
#undef _t
#undef _c
}
/* NUL-terminate and return. */
return rc[j] = '\0', rc;
fail:
return NULL;
}
/**
* Create duplicate of a string
*
* @param string The string
* @return A duplicate of the string, `NULL` on error or if `string` is `NULL`
*/
char32_t* string_dup(const char32_t* restrict string)
{
size_t n;
char32_t* rc;
if (string == NULL)
return NULL;
n = string_length(string) + 1;
fail_if (xmalloc(rc, n, char32_t));
memcpy(rc, string, n * sizeof(char32_t));
return rc;
fail:
return NULL;
}
|
