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@fbraem
Last active Aug 29, 2015
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UTF8Escape class for POCO
#include "Poco/UTF8Escape.h"
#include "Poco/UTF8Encoding.h"
#include "Poco/NumberFormatter.h"
#include "Poco/Ascii.h"
namespace Poco {
std::string UTF8Escape::escape(const std::string &s)
{
return escape(s.begin(), s.end());
}
std::string UTF8Escape::escape(std::string::const_iterator& begin, std::string::const_iterator& end)
{
static Poco::UInt32 offsetsFromUTF8[6] = {
0x00000000UL, 0x00003080UL, 0x000E2080UL,
0x03C82080UL, 0xFA082080UL, 0x82082080UL
};
std::string result;
std::string::const_iterator it = begin;
while(it != end)
{
Poco::UInt32 ch = 0;
unsigned int sz = 0;
do
{
ch <<= 6;
ch += (unsigned char)*it++;
sz++;
}
while (it != end && (*it & 0xC0) == 0x80 && sz < 6);
ch -= offsetsFromUTF8[sz-1];
if (ch == '\n') result += "\\n";
else if (ch == '\t') result += "\\t";
else if (ch == '\r') result += "\\r";
else if (ch == '\b') result += "\\b";
else if (ch == '\f') result += "\\f";
else if (ch == '\v') result += "\\v";
else if (ch == '\a') result += "\\a";
else if (ch == '\\') result += "\\\\";
else if (ch < 32 || ch == 0x7f)
{
result += "\\u";
NumberFormatter::appendHex(result, (unsigned short) ch, 4);
}
else if (ch > 0xFFFF)
{
ch -= 0x10000;
result += "\\u";
NumberFormatter::appendHex(result, (unsigned short) (( ch >> 10 ) & 0x03ff ) + 0xd800, 4);
result += "\\u";
NumberFormatter::appendHex(result, (unsigned short) (ch & 0x03ff ) + 0xdc00, 4);
}
else if (ch >= 0x80 && ch <= 0xFFFF)
{
result += "\\u";
NumberFormatter::appendHex(result, (unsigned short) ch, 4);
}
else
{
result += (char) ch;
}
}
return result;
}
std::string UTF8Escape::unescape(const std::string &s)
{
return unescape(s.begin(), s.end());
}
std::string UTF8Escape::unescape(std::string::const_iterator& begin, std::string::const_iterator& end)
{
std::string result;
std::string::const_iterator it = begin;
while (it != end)
{
Poco::UInt32 ch = (Poco::UInt32) *it++;
if (ch == '\\')
{
if ( it == end )
{
//Invalid sequence!
}
if (*it == 'n')
{
ch = '\n';
it++;
}
else if (*it == 't')
{
ch = '\t';
it++;
}
else if (*it == 'r')
{
ch = '\r';
it++;
}
else if (*it == 'b')
{
ch = '\b';
it++;
}
else if (*it == 'f')
{
ch = '\f';
it++;
}
else if (*it == 'v')
{
ch = '\v';
it++;
}
else if (*it == 'a')
{
ch = '\a';
it++;
}
else if (*it == 'u')
{
char digs[5];
memset(digs, 0, 5);
unsigned int dno = 0;
it++;
while (it != end && Ascii::isHexDigit(*it) && dno < 4) digs[dno++] = *it++;
if (dno > 0)
{
ch = strtol(digs, NULL, 16);
}
if( ch >= 0xD800 && ch <= 0xDBFF )
{
if ( it == end || *it != '\\' )
{
//Invalid sequence!
}
else
{
it++;
if ( it == end || *it != 'u' )
{
//Invalid sequence!
}
else
{
it++;
}
}
// UTF-16 surrogate pair. Go fetch other half
memset(digs, 0, 5);
dno = 0;
while (it != end && Ascii::isHexDigit(*it) && dno < 4) digs[dno++] = *it++;
if (dno > 0)
{
Poco::UInt32 temp = strtol(digs, NULL, 16);
if( temp >= 0xDC00 && temp <= 0xDFFF )
{
ch = ( ( ( ch - 0xD800 ) << 10 ) | ( temp - 0xDC00 ) ) + 0x10000;
}
}
}
}
else if (*it == 'U')
{
char digs[9];
memset(digs, 0, 9);
unsigned int dno = 0;
it++;
while (it != end && Ascii::isHexDigit(*it) && dno < 8)
{
digs[dno++] = *it++;
}
if (dno > 0)
{
ch = strtol(digs, NULL, 16);
}
}
}
unsigned char utf8[4];
UTF8Encoding encoding;
int sz = encoding.convert(ch, utf8, 4);
result.append((char*) utf8, sz);
}
return result;
}
} // Namespace Poco
//
// UTF8Escape.h
//
#ifndef Foundation_UTF8Escape_INCLUDED
#define Foundation_UTF8Escape_INCLUDED
namespace Poco {
class Foundation_API UTF8Escape
{
public:
static std::string escape(const std::string& s);
static std::string escape(std::string::const_iterator& begin, std::string::const_iterator& end);
static std::string unescape(const std::string& s);
static std::string unescape(std::string::const_iterator& begin, std::string::const_iterator& end);
private:
};
} // namespace Poco
#endif // Foundation_UTF8Escape_INCLUDED
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