static string DecodeRfc2231(out Encoding encoding, ref Decoder decoder, HexDecoder hex, byte[] text, int startIndex, int count, bool flush)
{
int endIndex = startIndex + count;
int index = startIndex;
string charset;
// Note: decoder is only null if this is the first segment
if (decoder == null)
{
if (TryGetCharset(text, ref index, endIndex, out charset))
{
try {
encoding = CharsetUtils.GetEncoding(charset, "?");
decoder = (Decoder)encoding.GetDecoder();
} catch (NotSupportedException) {
encoding = Encoding.GetEncoding(28591); // iso-8859-1
decoder = (Decoder)encoding.GetDecoder();
}
}
else
{
// When no charset is specified, it should be safe to assume US-ASCII...
// but we all know what assume means, right??
encoding = Encoding.GetEncoding(28591); // iso-8859-1
decoder = (Decoder)encoding.GetDecoder();
}
}
else
{
encoding = null;
}
int length = endIndex - index;
var decoded = new byte[hex.EstimateOutputLength(length)];
// hex decode...
length = hex.Decode(text, index, length, decoded);
int outLength = decoder.GetCharCount(decoded, 0, length, flush);
var output = new char[outLength];
outLength = decoder.GetChars(decoded, 0, length, output, 0, flush);
return(new string (output, 0, outLength));
}
internal static char[] ConvertToUnicode(Encoding encoding, byte[] input, int startIndex, int length, out int charCount)
{
var decoder = encoding.GetDecoder();
int count = decoder.GetCharCount(input, startIndex, length, true);
var output = new char[count];
charCount = decoder.GetChars(input, startIndex, length, output, 0, true);
return(output);
}
/// <summary>
/// Initializes a new instance of the <see cref="MimeKit.IO.Filters.CharsetFilter"/> class.
/// </summary>
/// <remarks>
/// Creates a new <see cref="CharsetFilter"/> to convert text from the specified
/// source encoding into the target charset encoding.
/// </remarks>
/// <param name="sourceEncoding">Source encoding.</param>
/// <param name="targetEncoding">Target encoding.</param>
/// <exception cref="System.ArgumentNullException">
/// <para><paramref name="sourceEncoding"/> is <c>null</c>.</para>
/// <para>-or-</para>
/// <para><paramref name="targetEncoding"/> is <c>null</c>.</para>
/// </exception>
public CharsetFilter(Encoding sourceEncoding, Encoding targetEncoding)
{
if (sourceEncoding == null)
{
throw new ArgumentNullException(nameof(sourceEncoding));
}
if (targetEncoding == null)
{
throw new ArgumentNullException(nameof(targetEncoding));
}
SourceEncoding = sourceEncoding;
TargetEncoding = targetEncoding;
decoder = (Decoder)SourceEncoding.GetDecoder();
encoder = (Encoder)TargetEncoding.GetEncoder();
}
/// <summary>
/// Initializes a new instance of the <see cref="MimeKit.IO.Filters.CharsetFilter"/> class.
/// </summary>
/// <remarks>
/// Creates a new <see cref="CharsetFilter"/> to convert text from the specified
/// source encoding into the target charset encoding.
/// </remarks>
/// <param name="sourceEncoding">Source encoding.</param>
/// <param name="targetEncoding">Target encoding.</param>
/// <exception cref="System.ArgumentNullException">
/// <para><paramref name="sourceEncoding"/> is <c>null</c>.</para>
/// <para>-or-</para>
/// <para><paramref name="targetEncoding"/> is <c>null</c>.</para>
/// </exception>
public CharsetFilter (Encoding sourceEncoding, Encoding targetEncoding)
{
if (sourceEncoding == null)
throw new ArgumentNullException ("sourceEncoding");
if (targetEncoding == null)
throw new ArgumentNullException ("targetEncoding");
SourceEncoding = sourceEncoding;
TargetEncoding = targetEncoding;
decoder = (Decoder) SourceEncoding.GetDecoder ();
encoder = (Encoder) TargetEncoding.GetEncoder ();
}
internal static char[] ConvertToUnicode (Encoding encoding, byte[] input, int startIndex, int length, out int charCount)
{
var decoder = encoding.GetDecoder ();
int count = decoder.GetCharCount (input, startIndex, length, true);
char[] output = new char[count];
charCount = decoder.GetChars (input, startIndex, length, output, 0, true);
return output;
}
