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
|
#include <utils/encoding.hpp>
#include <utils/binary.hpp>
#include <utils/scopeguard.hpp>
#include <assert.h>
#include <string.h>
#include <iconv.h>
#include <config.h>
/**
* The UTF-8-encoded character used as a place holder when a character conversion fails.
* This is U+FFFD � "replacement character"
*/
static const char* invalid_char = "\xef\xbf\xbd";
static const size_t invalid_char_len = 3;
namespace utils
{
/**
* Based on http://en.wikipedia.org/wiki/UTF-8#Description
*/
bool is_valid_utf8(const char* s)
{
if (!s)
return false;
const unsigned char* str = reinterpret_cast<const unsigned char*>(s);
while (*str)
{
// 4 bytes: 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
if ((str[0] & 11111000_b) == 11110000_b)
{
if (!str[1] || !str[2] || !str[3]
|| ((str[1] & 11000000_b) != 10000000_b)
|| ((str[2] & 11000000_b) != 10000000_b)
|| ((str[3] & 11000000_b) != 10000000_b))
return false;
str += 4;
}
// 3 bytes: 1110xxx 10xxxxxx 10xxxxxx
else if ((str[0] & 11110000_b) == 11100000_b)
{
if (!str[1] || !str[2]
|| ((str[1] & 11000000_b) != 10000000_b)
|| ((str[2] & 11000000_b) != 10000000_b))
return false;
str += 3;
}
// 2 bytes: 110xxxxx 10xxxxxx
else if (((str[0]) & 11100000_b) == 11000000_b)
{
if (!str[1] ||
((str[1] & 11000000_b) != 10000000_b))
return false;
str += 2;
}
// 1 byte: 0xxxxxxx
else if ((str[0] & 10000000_b) != 0)
return false;
else
str++;
}
return true;
}
std::string convert_to_utf8(const std::string& str, const char* charset)
{
std::string res;
const iconv_t cd = iconv_open("UTF-8", charset);
if (cd == (iconv_t)-1)
throw std::runtime_error("Cannot convert into UTF-8");
// Make sure cd is always closed when we leave this function
ScopeGuard sg([&]{ iconv_close(cd); });
size_t inbytesleft = str.size();
// iconv will not attempt to modify this buffer, but some plateform
// require a char** anyway
#ifdef ICONV_SECOND_ARGUMENT_IS_CONST
const char* inbuf_ptr = str.c_str();
#else
char* inbuf_ptr = const_cast<char*>(str.c_str());
#endif
size_t outbytesleft = str.size() * 4;
char* outbuf = new char[outbytesleft];
char* outbuf_ptr = outbuf;
// Make sure outbuf is always deleted when we leave this function
sg.add_callback([&]{ delete[] outbuf; });
bool done = false;
while (done == false)
{
size_t error = iconv(cd, &inbuf_ptr, &inbytesleft, &outbuf_ptr, &outbytesleft);
if ((size_t)-1 == error)
{
switch (errno)
{
case EILSEQ:
// Invalid byte found. Insert a placeholder instead of the
// converted character, jump one byte and continue
memcpy(outbuf_ptr, invalid_char, invalid_char_len);
outbuf_ptr += invalid_char_len;
inbytesleft--;
inbuf_ptr++;
break;
case EINVAL:
// A multibyte sequence is not terminated, but we can't
// provide any more data, so we just add a placeholder to
// indicate that the character is not properly converted,
// and we stop the conversion
memcpy(outbuf_ptr, invalid_char, invalid_char_len);
outbuf_ptr += invalid_char_len;
outbuf_ptr++;
done = true;
break;
case E2BIG:
// This should never happen
done = true;
default:
// This should happen even neverer
done = true;
break;
}
}
else
{
// The conversion finished without any error, stop converting
done = true;
}
}
// Terminate the converted buffer, and copy that buffer it into the
// string we return
*outbuf_ptr = '\0';
res = outbuf;
return res;
}
}
|
