/// <summary>
/// Resets the decoder.
/// </summary>
/// <remarks>
/// Resets the state of the decoder.
/// </remarks>
public void Reset ()
{
state = initial;
nsaved = 0;
saved = 0;
uulen = 0;
}
/// <summary>
/// Initializes a new instance of the <see cref="MimeKit.Encodings.UUDecoder"/> class.
/// </summary>
/// <remarks>
/// Creates a new Unix-to-Unix decoder.
/// </remarks>
/// <param name="payloadOnly">
/// If <c>true</c>, decoding begins immediately rather than after finding a begin-line.
/// </param>
public UUDecoder (bool payloadOnly)
{
initial = payloadOnly ? UUDecoderState.Payload : UUDecoderState.ExpectBegin;
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)
{
if (state == UUDecoderState.Ended)
return 0;
bool last_was_eoln = uulen == 0;
byte* inend = input + length;
byte* outptr = output;
byte* inptr = input;
byte c;
if (state < UUDecoderState.Payload) {
if ((inptr = ScanBeginMarker (inptr, inend)) == inend)
return 0;
}
while (inptr < inend) {
if (*inptr == (byte) '\r') {
inptr++;
continue;
}
if (*inptr == (byte) '\n') {
last_was_eoln = true;
inptr++;
continue;
}
if (uulen == 0 || last_was_eoln) {
// first octet on a line is the uulen octet
uulen = uudecode_rank[*inptr];
last_was_eoln = false;
if (uulen == 0) {
state = UUDecoderState.Ended;
break;
}
inptr++;
continue;
}
c = *inptr++;
if (uulen > 0) {
// save the byte
saved = (saved << 8) | c;
nsaved++;
if (nsaved == 4) {
byte b0 = (byte) ((saved >> 24) & 0xFF);
byte b1 = (byte) ((saved >> 16) & 0xFF);
byte b2 = (byte) ((saved >> 8) & 0xFF);
byte b3 = (byte) (saved & 0xFF);
if (uulen >= 3) {
*outptr++ = (byte) (uudecode_rank[b0] << 2 | uudecode_rank[b1] >> 4);
*outptr++ = (byte) (uudecode_rank[b1] << 4 | uudecode_rank[b2] >> 2);
*outptr++ = (byte) (uudecode_rank[b2] << 6 | uudecode_rank[b3]);
uulen -= 3;
} else {
if (uulen >= 1) {
*outptr++ = (byte) (uudecode_rank[b0] << 2 | uudecode_rank[b1] >> 4);
uulen--;
}
if (uulen >= 1) {
*outptr++ = (byte) (uudecode_rank[b1] << 4 | uudecode_rank[b2] >> 2);
uulen--;
}
}
nsaved = 0;
saved = 0;
}
} else {
break;
}
}
return (int) (outptr - output);
}
unsafe byte* ScanBeginMarker (byte* inptr, byte* inend)
{
while (inptr < inend) {
if (state == UUDecoderState.ExpectBegin) {
if (nsaved != 0 && nsaved != (byte) '\n') {
while (inptr < inend && *inptr != (byte) '\n')
inptr++;
if (inptr == inend) {
nsaved = *(inptr - 1);
return inptr;
}
nsaved = *inptr++;
if (inptr == inend)
return inptr;
}
nsaved = *inptr++;
if (nsaved != (byte) 'b')
continue;
state = UUDecoderState.B;
if (inptr == inend)
return inptr;
}
if (state == UUDecoderState.B) {
nsaved = *inptr++;
if (nsaved != (byte) 'e') {
state = UUDecoderState.ExpectBegin;
continue;
}
state = UUDecoderState.Be;
if (inptr == inend)
return inptr;
}
if (state == UUDecoderState.Be) {
nsaved = *inptr++;
if (nsaved != (byte) 'g') {
state = UUDecoderState.ExpectBegin;
continue;
}
state = UUDecoderState.Beg;
if (inptr == inend)
return inptr;
}
if (state == UUDecoderState.Beg) {
nsaved = *inptr++;
if (nsaved != (byte) 'i') {
state = UUDecoderState.ExpectBegin;
continue;
}
state = UUDecoderState.Begi;
if (inptr == inend)
return inptr;
}
if (state == UUDecoderState.Begi) {
nsaved = *inptr++;
if (nsaved != (byte) 'n') {
state = UUDecoderState.ExpectBegin;
continue;
}
state = UUDecoderState.Begin;
if (inptr == inend)
return inptr;
}
if (state == UUDecoderState.Begin) {
nsaved = *inptr++;
if (nsaved != (byte) ' ') {
state = UUDecoderState.ExpectBegin;
continue;
}
state = UUDecoderState.ExpectPayload;
if (inptr == inend)
return inptr;
}
if (state == UUDecoderState.ExpectPayload) {
while (inptr < inend && *inptr != (byte) '\n')
inptr++;
if (inptr == inend)
return inptr;
state = UUDecoderState.Payload;
nsaved = 0;
return inptr + 1;
}
}
return inptr;
}
/// <summary>
/// Initializes a new instance of the <see cref="MimeKit.Encodings.UUDecoder"/> class.
/// </summary>
/// <remarks>
/// Creates a new Unix-to-Unix decoder.
/// </remarks>
/// <param name="payloadOnly">
/// If <c>true</c>, decoding begins immediately rather than after finding a begin-line.
/// </param>
public UUDecoder(bool payloadOnly)
{
initial = payloadOnly ? UUDecoderState.Payload : UUDecoderState.ExpectBegin;
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)
{
if (state == UUDecoderState.Ended)
{
return(0);
}
bool last_was_eoln = uulen == 0;
byte *inend = input + length;
byte *outptr = output;
byte *inptr = input;
byte c;
if (state < UUDecoderState.Payload)
{
if ((inptr = ScanBeginMarker(inptr, inend)) == inend)
{
return(0);
}
}
while (inptr < inend)
{
if (*inptr == (byte)'\r')
{
inptr++;
continue;
}
if (*inptr == (byte)'\n')
{
last_was_eoln = true;
inptr++;
continue;
}
if (uulen == 0 || last_was_eoln)
{
// first octet on a line is the uulen octet
uulen = uudecode_rank[*inptr];
last_was_eoln = false;
if (uulen == 0)
{
state = UUDecoderState.Ended;
break;
}
inptr++;
continue;
}
c = *inptr++;
if (uulen > 0)
{
// save the byte
saved = (saved << 8) | c;
nsaved++;
if (nsaved == 4)
{
byte b0 = (byte)((saved >> 24) & 0xFF);
byte b1 = (byte)((saved >> 16) & 0xFF);
byte b2 = (byte)((saved >> 8) & 0xFF);
byte b3 = (byte)(saved & 0xFF);
if (uulen >= 3)
{
*outptr++ = (byte)(uudecode_rank[b0] << 2 | uudecode_rank[b1] >> 4);
*outptr++ = (byte)(uudecode_rank[b1] << 4 | uudecode_rank[b2] >> 2);
*outptr++ = (byte)(uudecode_rank[b2] << 6 | uudecode_rank[b3]);
uulen -= 3;
}
else
{
if (uulen >= 1)
{
*outptr++ = (byte)(uudecode_rank[b0] << 2 | uudecode_rank[b1] >> 4);
uulen--;
}
if (uulen >= 1)
{
*outptr++ = (byte)(uudecode_rank[b1] << 4 | uudecode_rank[b2] >> 2);
uulen--;
}
}
nsaved = 0;
saved = 0;
}
}
else
{
break;
}
}
return((int)(outptr - output));
}
unsafe byte *ScanBeginMarker(byte *inptr, byte *inend)
{
while (inptr < inend)
{
if (state == UUDecoderState.ExpectBegin)
{
if (nsaved != 0 && nsaved != (byte)'\n')
{
while (inptr < inend && *inptr != (byte)'\n')
{
inptr++;
}
if (inptr == inend)
{
nsaved = *(inptr - 1);
return(inptr);
}
nsaved = *inptr++;
if (inptr == inend)
{
return(inptr);
}
}
nsaved = *inptr++;
if (nsaved != (byte)'b')
{
continue;
}
state = UUDecoderState.B;
if (inptr == inend)
{
return(inptr);
}
}
if (state == UUDecoderState.B)
{
nsaved = *inptr++;
if (nsaved != (byte)'e')
{
state = UUDecoderState.ExpectBegin;
continue;
}
state = UUDecoderState.Be;
if (inptr == inend)
{
return(inptr);
}
}
if (state == UUDecoderState.Be)
{
nsaved = *inptr++;
if (nsaved != (byte)'g')
{
state = UUDecoderState.ExpectBegin;
continue;
}
state = UUDecoderState.Beg;
if (inptr == inend)
{
return(inptr);
}
}
if (state == UUDecoderState.Beg)
{
nsaved = *inptr++;
if (nsaved != (byte)'i')
{
state = UUDecoderState.ExpectBegin;
continue;
}
state = UUDecoderState.Begi;
if (inptr == inend)
{
return(inptr);
}
}
if (state == UUDecoderState.Begi)
{
nsaved = *inptr++;
if (nsaved != (byte)'n')
{
state = UUDecoderState.ExpectBegin;
continue;
}
state = UUDecoderState.Begin;
if (inptr == inend)
{
return(inptr);
}
}
if (state == UUDecoderState.Begin)
{
nsaved = *inptr++;
if (nsaved != (byte)' ')
{
state = UUDecoderState.ExpectBegin;
continue;
}
state = UUDecoderState.ExpectPayload;
if (inptr == inend)
{
return(inptr);
}
}
if (state == UUDecoderState.ExpectPayload)
{
while (inptr < inend && *inptr != (byte)'\n')
{
inptr++;
}
if (inptr == inend)
{
return(inptr);
}
state = UUDecoderState.Payload;
nsaved = 0;
return(inptr + 1);
}
}
return(inptr);
}
