bool nsGB18030ToUnicode::DecodeToSurrogate(const char* aSrc, char16_t* aOut)
{
NS_ASSERTION(FIRST_BYTE_IS_SURROGATE(aSrc[0]), "illegal first byte");
NS_ASSERTION(LEGAL_GBK_4BYTE_SECOND_BYTE(aSrc[1]), "illegal second byte");
NS_ASSERTION(LEGAL_GBK_4BYTE_THIRD_BYTE(aSrc[2]), "illegal third byte");
NS_ASSERTION(LEGAL_GBK_4BYTE_FORTH_BYTE(aSrc[3]), "illegal forth byte");
if(! FIRST_BYTE_IS_SURROGATE(aSrc[0]))
return false;
if(! LEGAL_GBK_4BYTE_SECOND_BYTE(aSrc[1]))
return false;
if(! LEGAL_GBK_4BYTE_THIRD_BYTE(aSrc[2]))
return false;
if(! LEGAL_GBK_4BYTE_FORTH_BYTE(aSrc[3]))
return false;
uint8_t a1 = (uint8_t) aSrc[0];
uint8_t a2 = (uint8_t) aSrc[1];
uint8_t a3 = (uint8_t) aSrc[2];
uint8_t a4 = (uint8_t) aSrc[3];
a1 -= (uint8_t)0x90;
a2 -= (uint8_t)0x30;
a3 -= (uint8_t)0x81;
a4 -= (uint8_t)0x30;
uint32_t idx = (((a1 * 10 + a2 ) * 126 + a3) * 10) + a4;
// idx == ucs4Codepoint - 0x10000
if (idx > 0x000FFFFF)
return false;
*aOut++ = 0xD800 | (idx >> 10);
*aOut = 0xDC00 | (0x000003FF & idx);
return true;
}
PRBool nsGB18030ToUnicode::DecodeToSurrogate(const char* aSrc, PRUnichar* aOut)
{
NS_ASSERTION(FIRST_BYTE_IS_SURROGATE(aSrc[0]), "illegal first byte");
NS_ASSERTION(LEGAL_GBK_4BYTE_SECOND_BYTE(aSrc[1]), "illegal second byte");
NS_ASSERTION(LEGAL_GBK_4BYTE_THIRD_BYTE(aSrc[2]), "illegal third byte");
NS_ASSERTION(LEGAL_GBK_4BYTE_FORTH_BYTE(aSrc[3]), "illegal forth byte");
if(! FIRST_BYTE_IS_SURROGATE(aSrc[0]))
return PR_FALSE;
if(! LEGAL_GBK_4BYTE_SECOND_BYTE(aSrc[1]))
return PR_FALSE;
if(! LEGAL_GBK_4BYTE_THIRD_BYTE(aSrc[2]))
return PR_FALSE;
if(! LEGAL_GBK_4BYTE_FORTH_BYTE(aSrc[3]))
return PR_FALSE;
PRUint8 a1 = (PRUint8) aSrc[0];
PRUint8 a2 = (PRUint8) aSrc[1];
PRUint8 a3 = (PRUint8) aSrc[2];
PRUint8 a4 = (PRUint8) aSrc[3];
a1 -= (PRUint8)0x90;
a2 -= (PRUint8)0x30;
a3 -= (PRUint8)0x81;
a4 -= (PRUint8)0x30;
PRUint32 idx = (((a1 * 10 + a2 ) * 126 + a3) * 10) + a4;
*aOut++ = 0xD800 | (0x000003FF & (idx >> 10));
*aOut = 0xDC00 | (0x000003FF & idx);
return PR_TRUE;
}
NS_IMETHODIMP nsGBKToUnicode::ConvertNoBuff(const char* aSrc,
int32_t * aSrcLength,
char16_t *aDest,
int32_t * aDestLength)
{
int32_t i=0;
int32_t iSrcLength = (*aSrcLength);
int32_t iDestlen = 0;
nsresult rv=NS_OK;
*aSrcLength = 0;
for (i=0;i<iSrcLength;i++)
{
if ( iDestlen >= (*aDestLength) )
{
rv = NS_OK_UDEC_MOREOUTPUT;
break;
}
// The valid range for the 1st byte is [0x81,0xFE]
if(LEGAL_GBK_MULTIBYTE_FIRST_BYTE(*aSrc))
{
if(i+1 >= iSrcLength)
{
rv = NS_OK_UDEC_MOREINPUT;
break;
}
// To make sure, the second byte has to be checked as well.
// In GBK, the second byte range is [0x40,0x7E] and [0x80,0XFE]
if(LEGAL_GBK_2BYTE_SECOND_BYTE(aSrc[1]))
{
// Valid GBK code
*aDest = mUtil.GBKCharToUnicode(aSrc[0], aSrc[1]);
if(UCS2_NO_MAPPING == *aDest)
{
// We cannot map in the common mapping, let's call the
// delegate 2 byte decoder to decode the gbk or gb18030 unique
// 2 byte mapping
if(! TryExtensionDecoder(aSrc, aDest))
{
*aDest = UCS2_NO_MAPPING;
}
}
aSrc += 2;
i++;
}
else if (LEGAL_GBK_4BYTE_SECOND_BYTE(aSrc[1]))
{
// from the first 2 bytes, it looks like a 4 byte GB18030
if(i+3 >= iSrcLength) // make sure we got 4 bytes
{
rv = NS_OK_UDEC_MOREINPUT;
break;
}
// 4 bytes patten
// [0x81-0xfe][0x30-0x39][0x81-0xfe][0x30-0x39]
// preset the
if (LEGAL_GBK_4BYTE_THIRD_BYTE(aSrc[2]) &&
LEGAL_GBK_4BYTE_FORTH_BYTE(aSrc[3]))
{
if ( ! FIRST_BYTE_IS_SURROGATE(aSrc[0]))
{
// let's call the delegated 4 byte gb18030 converter to convert it
if(! Try4BytesDecoder(aSrc, aDest))
*aDest = UCS2_NO_MAPPING;
} else {
// let's try supplement mapping
if ( (iDestlen+1) < (*aDestLength) )
{
if(DecodeToSurrogate(aSrc, aDest))
{
// surrogte two char16_t
iDestlen++;
aDest++;
} else {
*aDest = UCS2_NO_MAPPING;
}
} else {
if (*aDestLength < 2) {
NS_ERROR("insufficient space in output buffer");
*aDest = UCS2_NO_MAPPING;
} else {
rv = NS_OK_UDEC_MOREOUTPUT;
break;
}
}
}
aSrc += 4;
i += 3;
} else {
*aDest = UCS2_NO_MAPPING;
// If the third and fourth bytes are not in the legal ranges for
// a four-byte sequnce, resynchronize on the second byte
// (which we know is in the range of LEGAL_GBK_4BYTE_SECOND_BYTE,
// 0x30-0x39)
aSrc++;
}
}
else if ((uint8_t) aSrc[0] == (uint8_t)0xA0 )
{
// stand-alone (not followed by a valid second byte) 0xA0 !
// treat it as valid a la Netscape 4.x
*aDest = CAST_CHAR_TO_UNICHAR(*aSrc);
aSrc++;
} else {
// Invalid GBK code point (second byte should be 0x40 or higher)
*aDest = UCS2_NO_MAPPING;
aSrc++;
}
} else {
if(IS_ASCII(*aSrc))
{
// The source is an ASCII
*aDest = CAST_CHAR_TO_UNICHAR(*aSrc);
aSrc++;
} else {
if(IS_GBK_EURO(*aSrc)) {
*aDest = UCS2_EURO;
} else {
*aDest = UCS2_NO_MAPPING;
}
aSrc++;
}
}
iDestlen++;
aDest++;
*aSrcLength = i+1;
}
*aDestLength = iDestlen;
return rv;
}
