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#include <utils/encoding.hpp>
#include <utils/binary.hpp>
#include <utils/scopeguard.hpp>
#include <assert.h>
#include <string.h>
#include <iconv.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); });
// iconv will not attempt to modify this buffer, but it still requires
// a char**.
size_t inbytesleft = str.size();
char* inbuf_ptr = const_cast<char*>(str.c_str());
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;
}
}
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