poco/Foundation/src/UTF8Encoding.cpp
2012-02-05 12:16:58 +00:00

273 lines
6.8 KiB
C++

//
// UTF8Encoding.cpp
//
// $Id: //poco/1.4/Foundation/src/UTF8Encoding.cpp#1 $
//
// Library: Foundation
// Package: Text
// Module: UTF8Encoding
//
// Copyright (c) 2004-2007, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// Permission is hereby granted, free of charge, to any person or organization
// obtaining a copy of the software and accompanying documentation covered by
// this license (the "Software") to use, reproduce, display, distribute,
// execute, and transmit the Software, and to prepare derivative works of the
// Software, and to permit third-parties to whom the Software is furnished to
// do so, all subject to the following:
//
// The copyright notices in the Software and this entire statement, including
// the above license grant, this restriction and the following disclaimer,
// must be included in all copies of the Software, in whole or in part, and
// all derivative works of the Software, unless such copies or derivative
// works are solely in the form of machine-executable object code generated by
// a source language processor.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//
#include "Poco/UTF8Encoding.h"
#include "Poco/String.h"
namespace Poco {
const char* UTF8Encoding::_names[] =
{
"UTF-8",
"UTF8",
NULL
};
const TextEncoding::CharacterMap UTF8Encoding::_charMap =
{
/* 00 */ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
/* 10 */ 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
/* 20 */ 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
/* 30 */ 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
/* 40 */ 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
/* 50 */ 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f,
/* 60 */ 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
/* 70 */ 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f,
/* 80 */ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
/* 90 */ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
/* a0 */ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
/* b0 */ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
/* c0 */ -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
/* d0 */ -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
/* e0 */ -3, -3, -3, -3, -3, -3, -3, -3, -3, -3, -3, -3, -3, -3, -3, -3,
/* f0 */ -4, -4, -4, -4, -4, -4, -4, -4, -5, -5, -5, -5, -6, -6, -1, -1,
};
UTF8Encoding::UTF8Encoding()
{
}
UTF8Encoding::~UTF8Encoding()
{
}
const char* UTF8Encoding::canonicalName() const
{
return _names[0];
}
bool UTF8Encoding::isA(const std::string& encodingName) const
{
for (const char** name = _names; *name; ++name)
{
if (Poco::icompare(encodingName, *name) == 0)
return true;
}
return false;
}
const TextEncoding::CharacterMap& UTF8Encoding::characterMap() const
{
return _charMap;
}
int UTF8Encoding::convert(const unsigned char* bytes) const
{
int n = _charMap[*bytes];
int uc;
switch (n)
{
case -6:
case -5:
case -1:
return -1;
case -4:
case -3:
case -2:
if (!isLegal(bytes, -n)) return -1;
uc = *bytes & ((0x07 << (n + 4)) | 0x03);
break;
default:
return n;
}
while (n++ < -1)
{
uc <<= 6;
uc |= (*++bytes & 0x3F);
}
return uc;
}
int UTF8Encoding::convert(int ch, unsigned char* bytes, int length) const
{
if (ch <= 0x7F)
{
if (bytes && length >= 1)
*bytes = (unsigned char) ch;
return 1;
}
else if (ch <= 0x7FF)
{
if (bytes && length >= 2)
{
*bytes++ = (unsigned char) (((ch >> 6) & 0x1F) | 0xC0);
*bytes = (unsigned char) ((ch & 0x3F) | 0x80);
}
return 2;
}
else if (ch <= 0xFFFF)
{
if (bytes && length >= 3)
{
*bytes++ = (unsigned char) (((ch >> 12) & 0x0F) | 0xE0);
*bytes++ = (unsigned char) (((ch >> 6) & 0x3F) | 0x80);
*bytes = (unsigned char) ((ch & 0x3F) | 0x80);
}
return 3;
}
else if (ch <= 0x10FFFF)
{
if (bytes && length >= 4)
{
*bytes++ = (unsigned char) (((ch >> 18) & 0x07) | 0xF0);
*bytes++ = (unsigned char) (((ch >> 12) & 0x3F) | 0x80);
*bytes++ = (unsigned char) (((ch >> 6) & 0x3F) | 0x80);
*bytes = (unsigned char) ((ch & 0x3F) | 0x80);
}
return 4;
}
else return 0;
}
int UTF8Encoding::queryConvert(const unsigned char* bytes, int length) const
{
int n = _charMap[*bytes];
int uc;
if (-n > length)
{
return n;
}
else
{
switch (n)
{
case -6:
case -5:
case -1:
return -1;
case -4:
case -3:
case -2:
if (!isLegal(bytes, -n)) return -1;
uc = *bytes & ((0x07 << (n + 4)) | 0x03);
break;
default:
return n;
}
while (n++ < -1)
{
uc <<= 6;
uc |= (*++bytes & 0x3F);
}
return uc;
}
}
int UTF8Encoding::sequenceLength(const unsigned char* bytes, int length) const
{
if (1 <= length)
{
int cc = _charMap[*bytes];
if (cc >= 0)
return 1;
else
return -cc;
}
else return -1;
}
bool UTF8Encoding::isLegal(const unsigned char *bytes, int length)
{
// Note: The following is loosely based on the isLegalUTF8 function
// from ftp://ftp.unicode.org/Public/PROGRAMS/CVTUTF/ConvertUTF.c
// Excuse the ugliness...
if (0 == bytes || 0 == length) return false;
unsigned char a;
const unsigned char* srcptr = bytes + length;
switch (length)
{
default:
return false;
// Everything else falls through when true.
case 4:
if ((a = (*--srcptr)) < 0x80 || a > 0xBF) return false;
case 3:
if ((a = (*--srcptr)) < 0x80 || a > 0xBF) return false;
case 2:
if ((a = (*--srcptr)) > 0xBF) return false;
switch (*bytes)
{
case 0xE0:
if (a < 0xA0) return false;
break;
case 0xED:
if (a > 0x9F) return false;
break;
case 0xF0:
if (a < 0x90) return false;
break;
case 0xF4:
if (a > 0x8F) return false;
break;
default:
if (a < 0x80) return false;
}
case 1:
if (*bytes >= 0x80 && *bytes < 0xC2) return false;
}
return *bytes <= 0xF4;
}
} // namespace Poco