internal XmlScanner(XmlStreamReader reader, XmlNameTable ntable) : this(reader, ntable, null) {
// Intentionally Empty
}
internal XmlScanner(XmlStreamReader reader, XmlNameTable ntable, Encoding enc) : this(ntable) {
_nLineNum = 1;
_StreamReader = reader;
_TextReader = null;
_nSize = (int) ((reader.CanCalcLength && reader.Length < BUFSIZE) ? reader.Length:BUFSIZE);
_ByteBuffer = new byte[_nSize+1];
_ByteLen = _StreamReader.Read(_ByteBuffer, 0, _nSize);
_ByteStart = 0;
_nCodePage = 0;
if (null != enc) {
_Encoding = enc;
}
else {
_Encoding = null;
switch(AutoDetectEncoding(_ByteBuffer))
{
case UniCodeBE://2:
_Encoding = Encoding.BigEndianUnicode;
break;
case UniCode: //3:
_Encoding = Encoding.Unicode;
break;
case UCS4BE: //4:
case UCS4BEB: // 5:
_Encoding = Ucs4Encoding.UCS4_Bigendian;
break;
case UCS4: //6:
case UCS4B: //7:
_Encoding = Ucs4Encoding.UCS4_Littleendian;
break;
case UCS434://8:
case UCS434B: //9:
_Encoding = Ucs4Encoding.UCS4_3412;
break;
case UCS421: //10:
case UCS421B://11:
_Encoding = Ucs4Encoding.UCS4_2143;
break;
case EBCDIC: //12: ebcdic
throw new XmlException(Res.Xml_UnknownEncoding, "ebcdic", LineNum, LinePos);
//break;
case UTF8: //13:
_EncodingSetByDefault = true;
_Encoding = new UTF8Encoding(true);
break;
default:
_Encoding = new UTF8Encoding(true, true);
break;
}
}
_Decoder = _Encoding.GetDecoder();
_PermitEncodingChange = true;
if(_Encoding != null)
_nCodePage = _Encoding.CodePage;
_achText = new char[_nSize+1];
int preambleLength = 0;
try {
byte[] preamble = _Encoding.GetPreamble();
preambleLength = preamble.Length;
bool hasByteOrderMark = true;
for (int i = 0; i < preambleLength && hasByteOrderMark; i++) {
hasByteOrderMark &= (_ByteBuffer[i] == preamble[i]);
}
if (hasByteOrderMark) {
_ByteStart = preambleLength;
}
}
catch (Exception) {
}
_nUsed += GetChars(_ByteBuffer, ref _ByteStart , _ByteLen - _ByteStart, _achText, 0, true);
_achText[_nUsed] = (char)0;
}
// Initialize the scanner given a StreamReader.
internal XmlScanner(TextReader reader, XmlNameTable ntable) : this(ntable) {
const int BUFSIZE_SMALL = 256;
_TextReader = reader;
_StreamReader = null;
_nSize = BUFSIZE;
StreamReader streamReader = reader as StreamReader;
if (streamReader != null) {
Stream stream = streamReader.BaseStream;
if (stream.CanSeek && stream.Length < BUFSIZE) {
_nSize = BUFSIZE_SMALL;
}
}
_achText = new char[_nSize+1];
_PermitEncodingChange = false;
_Encoding = Encoding.Unicode;
//no need to check Encoding, start reading
Read();
}