/// <summary>
/// Resets the decoder.
/// </summary>
/// <remarks>
/// Resets the state of the decoder.
/// </remarks>
public void Reset()
{
octet = (byte)'\n';
state = initial;
escaped = false;
eoln = true;
crc.Reset();
}
/// <summary>
/// Initializes a new instance of the <see cref="MimeKit.Encodings.YDecoder"/> class.
/// </summary>
/// <remarks>
/// Creates a new yEnc decoder.
/// </remarks>
/// <param name="payloadOnly">
/// If <c>true</c>, decoding begins immediately rather than after finding an =ybegin line.
/// </param>
public YDecoder(bool payloadOnly)
{
initial = payloadOnly ? YDecoderState.Payload : YDecoderState.ExpectYBegin;
crc = new Crc32(-1);
Reset();
}
/// <summary>
/// Decodes the specified input into the output buffer.
/// </summary>
/// <remarks>
/// <para>Decodes the specified input into the output buffer.</para>
/// <para>The output buffer should be large enough to hold all of the
/// decoded input. For estimating the size needed for the output buffer,
/// see <see cref="EstimateOutputLength"/>.</para>
/// </remarks>
/// <returns>The number of bytes written to the output buffer.</returns>
/// <param name="input">A pointer to the beginning of the input buffer.</param>
/// <param name="length">The length of the input buffer.</param>
/// <param name="output">A pointer to the beginning of the output buffer.</param>
public unsafe int Decode(byte *input, int length, byte *output)
{
byte *inend = input + length;
byte *outptr = output;
byte *inptr = input;
if (state < YDecoderState.Payload)
{
if ((inptr = ScanYBeginMarker(inptr, inend)) == inend)
{
return(0);
}
eoln = true;
}
if (state == YDecoderState.Ended)
{
return(0);
}
while (inptr < inend)
{
octet = *inptr++;
if (octet == (byte)'\r')
{
escaped = false;
continue;
}
if (octet == (byte)'\n')
{
escaped = false;
eoln = true;
continue;
}
if (escaped)
{
if (eoln && octet == (byte)'y')
{
// this can only be =yend
state = YDecoderState.Ended;
break;
}
escaped = false;
eoln = false;
octet -= 64;
}
else if (octet == (byte)'=')
{
escaped = true;
continue;
}
else
{
eoln = false;
}
octet -= 42;
crc.Update(octet);
*outptr++ = octet;
}
return((int)(outptr - output));
}
unsafe byte *ScanYBeginMarker(byte *inptr, byte *inend)
{
while (inptr < inend)
{
if (state == YDecoderState.ExpectYBegin)
{
if (octet != (byte)'\n')
{
while (inptr < inend && *inptr != (byte)'\n')
{
inptr++;
}
if (inptr == inend)
{
octet = *(inptr - 1);
break;
}
octet = *inptr++;
if (inptr == inend)
{
break;
}
}
octet = *inptr++;
if (octet != (byte)'=')
{
continue;
}
state = YDecoderState.YBeginEqual;
if (inptr == inend)
{
break;
}
}
if (state == YDecoderState.YBeginEqual)
{
octet = *inptr++;
if (octet != (byte)'y')
{
state = YDecoderState.ExpectYBegin;
continue;
}
state = YDecoderState.YBeginEqualY;
if (inptr == inend)
{
break;
}
}
if (state == YDecoderState.YBeginEqualY)
{
octet = *inptr++;
if (octet != (byte)'b')
{
state = YDecoderState.ExpectYBegin;
continue;
}
state = YDecoderState.YBeginEqualYB;
if (inptr == inend)
{
break;
}
}
if (state == YDecoderState.YBeginEqualYB)
{
octet = *inptr++;
if (octet != (byte)'e')
{
state = YDecoderState.ExpectYBegin;
continue;
}
state = YDecoderState.YBeginEqualYBe;
if (inptr == inend)
{
break;
}
}
if (state == YDecoderState.YBeginEqualYBe)
{
octet = *inptr++;
if (octet != (byte)'g')
{
state = YDecoderState.ExpectYBegin;
continue;
}
state = YDecoderState.YBeginEqualYBeg;
if (inptr == inend)
{
break;
}
}
if (state == YDecoderState.YBeginEqualYBeg)
{
octet = *inptr++;
if (octet != (byte)'i')
{
state = YDecoderState.ExpectYBegin;
continue;
}
state = YDecoderState.YBeginEqualYBegi;
if (inptr == inend)
{
break;
}
}
if (state == YDecoderState.YBeginEqualYBegi)
{
octet = *inptr++;
if (octet != (byte)'n')
{
state = YDecoderState.ExpectYBegin;
continue;
}
state = YDecoderState.YBeginEqualYBegin;
if (inptr == inend)
{
break;
}
}
if (state == YDecoderState.YBeginEqualYBegin)
{
octet = *inptr++;
if (octet != (byte)' ')
{
state = YDecoderState.ExpectYBegin;
continue;
}
state = YDecoderState.ExpectYBeginNewLine;
if (inptr == inend)
{
break;
}
}
if (state == YDecoderState.ExpectYBeginNewLine)
{
while (inptr < inend && *inptr != (byte)'\n')
{
inptr++;
}
if (inptr == inend)
{
octet = *(inptr - 1);
break;
}
state = YDecoderState.ExpectYPartOrPayload;
octet = *inptr++;
break;
}
if (state == YDecoderState.ExpectYPartOrPayload)
{
if (*inptr != (byte)'=')
{
state = YDecoderState.Payload;
break;
}
state = YDecoderState.YPartEqual;
octet = *inptr++;
escaped = true;
if (inptr == inend)
{
break;
}
}
if (state == YDecoderState.YPartEqual)
{
if (*inptr != (byte)'y')
{
state = YDecoderState.Payload;
return(inptr);
}
state = YDecoderState.YPartEqualY;
octet = *inptr++;
if (inptr == inend)
{
break;
}
}
if (state == YDecoderState.YPartEqualY)
{
if (*inptr == (byte)'e')
{
// we got an "=ye" which can only be an "=yend"
state = YDecoderState.Ended;
return(inptr);
}
if (*inptr != (byte)'p')
{
state = YDecoderState.ExpectYBeginNewLine;
continue;
}
state = YDecoderState.YPartEqualYP;
octet = *inptr++;
if (inptr == inend)
{
break;
}
}
if (state == YDecoderState.YPartEqualYP)
{
if (*inptr != (byte)'a')
{
state = YDecoderState.ExpectYBeginNewLine;
continue;
}
state = YDecoderState.YPartEqualYPa;
octet = *inptr++;
if (inptr == inend)
{
break;
}
}
if (state == YDecoderState.YPartEqualYPa)
{
if (*inptr != (byte)'r')
{
state = YDecoderState.ExpectYBeginNewLine;
continue;
}
state = YDecoderState.YPartEqualYPar;
octet = *inptr++;
if (inptr == inend)
{
break;
}
}
if (state == YDecoderState.YPartEqualYPar)
{
if (*inptr != (byte)'t')
{
state = YDecoderState.ExpectYBeginNewLine;
continue;
}
state = YDecoderState.YPartEqualYPart;
octet = *inptr++;
if (inptr == inend)
{
break;
}
}
if (state == YDecoderState.YPartEqualYPart)
{
if (*inptr != (byte)' ')
{
state = YDecoderState.ExpectYBeginNewLine;
continue;
}
state = YDecoderState.ExpectYPartNewLine;
octet = *inptr++;
if (inptr == inend)
{
break;
}
}
if (state == YDecoderState.ExpectYPartNewLine)
{
while (inptr < inend && *inptr != (byte)'\n')
{
inptr++;
}
if (inptr == inend)
{
octet = *(inptr - 1);
break;
}
state = YDecoderState.Payload;
octet = *inptr++;
break;
}
}
return(inptr);
}
/// <summary>
/// Initializes a new instance of the <see cref="MimeKit.Encodings.YDecoder"/> class.
/// </summary>
/// <remarks>
/// Creates a new yEnc decoder.
/// </remarks>
/// <param name="payloadOnly">
/// If <c>true</c>, decoding begins immediately rather than after finding an =ybegin line.
/// </param>
public YDecoder (bool payloadOnly)
{
initial = payloadOnly ? YDecoderState.Payload : YDecoderState.ExpectYBegin;
crc = new Crc32 (-1);
Reset ();
}
/// <summary>
/// Resets the decoder.
/// </summary>
/// <remarks>
/// Resets the state of the decoder.
/// </remarks>
public void Reset ()
{
octet = (byte) '\n';
state = initial;
escaped = false;
eoln = true;
crc.Reset ();
}
/// <summary>
/// Decodes the specified input into the output buffer.
/// </summary>
/// <remarks>
/// <para>Decodes the specified input into the output buffer.</para>
/// <para>The output buffer should be large enough to hold all of the
/// decoded input. For estimating the size needed for the output buffer,
/// see <see cref="EstimateOutputLength"/>.</para>
/// </remarks>
/// <returns>The number of bytes written to the output buffer.</returns>
/// <param name="input">A pointer to the beginning of the input buffer.</param>
/// <param name="length">The length of the input buffer.</param>
/// <param name="output">A pointer to the beginning of the output buffer.</param>
public unsafe int Decode (byte* input, int length, byte* output)
{
byte* inend = input + length;
byte* outptr = output;
byte* inptr = input;
if (state < YDecoderState.Payload) {
if ((inptr = ScanYBeginMarker (inptr, inend)) == inend)
return 0;
eoln = true;
}
if (state == YDecoderState.Ended)
return 0;
while (inptr < inend) {
octet = *inptr++;
if (octet == (byte) '\r') {
escaped = false;
continue;
}
if (octet == (byte) '\n') {
escaped = false;
eoln = true;
continue;
}
if (escaped) {
if (eoln && octet == (byte) 'y') {
// this can only be =yend
state = YDecoderState.Ended;
break;
}
escaped = false;
eoln = false;
octet -= 64;
} else if (octet == (byte) '=') {
escaped = true;
continue;
} else {
eoln = false;
}
octet -= 42;
crc.Update (octet);
*outptr++ = octet;
}
return (int) (outptr - output);
}
unsafe byte* ScanYBeginMarker (byte* inptr, byte* inend)
{
while (inptr < inend) {
if (state == YDecoderState.ExpectYBegin) {
if (octet != (byte) '\n') {
while (inptr < inend && *inptr != (byte) '\n')
inptr++;
if (inptr == inend) {
octet = *(inptr - 1);
break;
}
octet = *inptr++;
if (inptr == inend)
break;
}
octet = *inptr++;
if (octet != (byte) '=')
continue;
state = YDecoderState.YBeginEqual;
if (inptr == inend)
break;
}
if (state == YDecoderState.YBeginEqual) {
octet = *inptr++;
if (octet != (byte) 'y') {
state = YDecoderState.ExpectYBegin;
continue;
}
state = YDecoderState.YBeginEqualY;
if (inptr == inend)
break;
}
if (state == YDecoderState.YBeginEqualY) {
octet = *inptr++;
if (octet != (byte) 'b') {
state = YDecoderState.ExpectYBegin;
continue;
}
state = YDecoderState.YBeginEqualYB;
if (inptr == inend)
break;
}
if (state == YDecoderState.YBeginEqualYB) {
octet = *inptr++;
if (octet != (byte) 'e') {
state = YDecoderState.ExpectYBegin;
continue;
}
state = YDecoderState.YBeginEqualYBe;
if (inptr == inend)
break;
}
if (state == YDecoderState.YBeginEqualYBe) {
octet = *inptr++;
if (octet != (byte) 'g') {
state = YDecoderState.ExpectYBegin;
continue;
}
state = YDecoderState.YBeginEqualYBeg;
if (inptr == inend)
break;
}
if (state == YDecoderState.YBeginEqualYBeg) {
octet = *inptr++;
if (octet != (byte) 'i') {
state = YDecoderState.ExpectYBegin;
continue;
}
state = YDecoderState.YBeginEqualYBegi;
if (inptr == inend)
break;
}
if (state == YDecoderState.YBeginEqualYBegi) {
octet = *inptr++;
if (octet != (byte) 'n') {
state = YDecoderState.ExpectYBegin;
continue;
}
state = YDecoderState.YBeginEqualYBegin;
if (inptr == inend)
break;
}
if (state == YDecoderState.YBeginEqualYBegin) {
octet = *inptr++;
if (octet != (byte) ' ') {
state = YDecoderState.ExpectYBegin;
continue;
}
state = YDecoderState.ExpectYBeginNewLine;
if (inptr == inend)
break;
}
if (state == YDecoderState.ExpectYBeginNewLine) {
while (inptr < inend && *inptr != (byte) '\n')
inptr++;
if (inptr == inend) {
octet = *(inptr - 1);
break;
}
state = YDecoderState.ExpectYPartOrPayload;
octet = *inptr++;
break;
}
if (state == YDecoderState.ExpectYPartOrPayload) {
if (*inptr != (byte) '=') {
state = YDecoderState.Payload;
break;
}
state = YDecoderState.YPartEqual;
octet = *inptr++;
escaped = true;
if (inptr == inend)
break;
}
if (state == YDecoderState.YPartEqual) {
if (*inptr != (byte) 'y') {
state = YDecoderState.Payload;
return inptr;
}
state = YDecoderState.YPartEqualY;
octet = *inptr++;
if (inptr == inend)
break;
}
if (state == YDecoderState.YPartEqualY) {
if (*inptr == (byte) 'e') {
// we got an "=ye" which can only be an "=yend"
state = YDecoderState.Ended;
return inptr;
}
if (*inptr != (byte) 'p') {
state = YDecoderState.ExpectYBeginNewLine;
continue;
}
state = YDecoderState.YPartEqualYP;
octet = *inptr++;
if (inptr == inend)
break;
}
if (state == YDecoderState.YPartEqualYP) {
if (*inptr != (byte) 'a') {
state = YDecoderState.ExpectYBeginNewLine;
continue;
}
state = YDecoderState.YPartEqualYPa;
octet = *inptr++;
if (inptr == inend)
break;
}
if (state == YDecoderState.YPartEqualYPa) {
if (*inptr != (byte) 'r') {
state = YDecoderState.ExpectYBeginNewLine;
continue;
}
state = YDecoderState.YPartEqualYPar;
octet = *inptr++;
if (inptr == inend)
break;
}
if (state == YDecoderState.YPartEqualYPar) {
if (*inptr != (byte) 't') {
state = YDecoderState.ExpectYBeginNewLine;
continue;
}
state = YDecoderState.YPartEqualYPart;
octet = *inptr++;
if (inptr == inend)
break;
}
if (state == YDecoderState.YPartEqualYPart) {
if (*inptr != (byte) ' ') {
state = YDecoderState.ExpectYBeginNewLine;
continue;
}
state = YDecoderState.ExpectYPartNewLine;
octet = *inptr++;
if (inptr == inend)
break;
}
if (state == YDecoderState.ExpectYPartNewLine) {
while (inptr < inend && *inptr != (byte) '\n')
inptr++;
if (inptr == inend) {
octet = *(inptr - 1);
break;
}
state = YDecoderState.Payload;
octet = *inptr++;
break;
}
}
return inptr;
}
